[0001] Fabric items such as clothing, towels, bedding, etc. can be colored using a variety
of different dyes and dyeing processes. In a residential setting, caring for these
dyed fabric items may present consumers with several challenges. Some dyed fabric
items may have excess or loose dye that can wash off during a normal wash cycle in
a clothes washer and redeposit on other items in the laundry load or bleed onto differently
dyed areas of the same item, for example. Excess or loose dyes may also rub off onto
the consumer or other surfaces during wear or use. Sorting the laundry items before
washing into loads of "like color" or washing items separately may address some dye
transfer concerns, but can be time consuming and inefficient for the user. In addition,
mistakes in sorting loads can lead to dye transfer which cannot be easily removed,
potentially ruining the item.
[0002] US-A1-2007/0084000 discloses a cycle of operation for a laundry treating appliance, and a laundry treating
appliance, on which the precharacterizing portions of the independent claims are based.
It discloses alternating the speed of rotation of the automatic washer wash basket
from a low spin speed to a high spin speed and applying a concentrated solution to
the textiles when the wash basket is spinning at the low spin speed. Chemicals for
producing wash chemistry are supplied into a space between the tub and the wash basket
so that they pass to the sump region of the tub before being mixed with water and
then being supplied in a recirculation system to the wash basket.
US-A1-2007/0283508 discloses an automatic washing machine in which a pre-wash step can comprise recirculating
a first volume of liquid between the tub and the drum without submerging a portion
of the drum in the liquid, and rotating the drum.
[0003] According to an aspect of the invention, as defined by claim 1, a cycle of operation
for a laundry treating appliance having a tub and a rotatable, perforated drum located
within the tub and operably coupled with a motor for rotating the drum, the drum at
least partially defining a treating chamber for receiving laundry for treatment according
to a cycle of operation comprises a pre-wash phase and a main wash phase. The pre-wash
phase includes rotating the drum to impart a centrifugal force to the laundry sufficient
to distribute the laundry about the periphery of the drum to form an annulus of laundry
within the treating chamber and supplying a treating chemistry comprising at least
one substance other than water to the tub via the drum by supplying the treating chemistry
through a center of the annulus of laundry such that the treating chemistry bypasses
the laundry and flows through the perforations in the drum into the tub.
[0004] The cycle of operation may further comprise wetting the laundry with water prior
to forming the annulus of laundry. Rotating the drum to impart a centrifugal force
may comprise rotating the drum at a satellizing speed. The supplying the treating
chemistry may occur when a speed of rotation of the drum satisfies a predetermined
threshold less than the satellizing speed. The drum may further comprise an impeller
inside the drum and mounted on a rotational axis of the drum and the supplying of
the treating chemistry to the tub comprises supplying the treating chemistry onto
the impeller.
[0005] The supplying of the liquid to the tub may be contemporaneous with or after the supplying
of the treating chemistry. The cycle of operation may further comprise rotating the
drum to redistribute the laundry in the drum from the annulus after the supplying
of the treating chemistry to the tub. Rotating the drum to redistribute the laundry
may comprise alternately turning the motor on and off or reversing a direction of
rotation of the drum. The cycle of operation may further comprise mixing the mixture
of liquid and the treating chemistry prior to supplying the mixture onto the laundry.
The mixing may comprise supplying water to a first predetermined liquid level in the
tub and rotating the drum to a predetermined speed to agitate the mixture of liquid
and the treating chemistry in the tub.
[0006] The supplying of the mixture onto the laundry may comprise wetting a portion of the
laundry adjacent a side wall of the drum. The wetting a portion of the laundry may
comprise rotating the drum at a predetermined speed to draw the mixture up the side
wall of the drum.
[0007] Another aspect of the invention provides a laundry treating appliance as defined
by claim 2.
[0008] The liquid supply system may be controlled to wet the laundry with water prior to
forming the annulus of laundry. The drum may further comprise an impeller inside the
drum and mounted on a rotational axis of the drum configured to direct treating chemistry
dispensed onto the impeller to the drum.
[0009] The impeller may comprise a plurality of apertures, wherein treating chemistry dispensed
onto the impeller flows through the apertures to the drum. The dispensing system may
comprise at least one sprayer configured to spray the treating chemistry into the
center of the annulus of the laundry.
[0010] Controlling the motor to rotate the drum to impart a centrifugal force may comprise
rotating the drum at a satellizing speed. The supplying the treating chemistry may
occur when a speed of rotation of the drum satisfies a predetermined threshold less
than the satellizing speed.
[0011] The dispensing system may be controlled to supply the liquid to the tub contemporaneously
with or after the supplying the treating chemistry. The laundry treating appliance
may be adapted to control the motor to rotate the drum to redistribute the laundry
in the drum from the annulus after the supplying the treating chemistry to the tub.
Controlling the motor to rotate the drum to redistribute the laundry comprises alternately
turning the motor on and off or reversing a direction of rotation of the drum.
[0012] Controlling the liquid supply system to supply liquid to the tub to form a mixture
of the liquid and the treating chemistry may comprise supplying liquid to a first
liquid level in the tub. The laundry treating appliance may be adapted to control
the motor to rotate the drum to a predetermined speed to agitate the mixture of liquid
and the treating chemistry in the tub.
[0013] Controlling the recirculation system to supply the mixture in the tub onto the laundry
may comprise wetting a portion of the laundry adjacent a side wall of the drum. Wetting
a portion of the laundry may comprise controlling the motor to rotate the drum at
a predetermined speed to draw the mixture up the side wall of the drum.
[0014] The treating chemistry may comprise a dye absorber, a dye fixative, a fabric softener
or combinations thereof.
[0015] The present invention will be further described by way of example with reference
to the accompanying drawings in which:-
Figure 1 is a flow chart illustrating a wash cycle for inhibiting dye transfer according
to an embodiment of the invention.
Figures 2A and 2B are cross-section, schematic side views of a vertical axis clothes
washer according to an embodiment of the invention.
Figure 3 is a schematic representation of a controller for controlling the operation
of one or more components of the clothes washer of Figures 2A and 2B according to
an embodiment of the invention.
Figure 4 is a flow chart illustrating a method for supplying a treating chemistry
according to an embodiment of the invention.
Figure 5 is a flow chart illustrating a method for supplying a treating chemistry,
such as a dye fixative, according to an embodiment of the invention.
Figures 6A, 6B and 6C are cross-section, schematic side views of a clothes washer
illustrating a method for wetting a laundry load according to an embodiment of the
invention.
Figure 7 is a flow chart illustrating a method for supplying a treating chemistry
to a laundry item according to an embodiment of the invention.
Figure 8 is a flow chart illustrating methods for implementing an intermediate phase
according to an embodiment of the invention.
Figure 9 is a flow chart illustrating a method for implementing a rinse phase according
to an embodiment of the invention.
Figure 10 is a cross-section, schematic side view of a horizontal axis clothes washer
according to an embodiment of the invention.
Figure 11 is a flow chart illustrating a method for supplying a treating chemistry
according to an embodiment of the invention.
Figure 12 is a graph representing change in concentration of a dye fixative over time
according to an embodiment of the invention.
Figure 13 is a flow chart illustrating a method for determining an amount of dye absorber
to supply during a cycle of operation according to an embodiment of the invention.
Figure 14 is a representative absorbance spectrum for a dye absorber in the presence
and absence of a dye according to an embodiment of the invention.
Figure 15 is a flow chart illustrating a method for removing dye according to an embodiment
of the invention.
Figure 16 is a flow chart illustrating a method for inhibiting dye transfer during
a cycle of operation according to an embodiment of the invention.
Figure 17A is a flow chart illustrating a method for supplying a dye fixative to a
laundry load according to an embodiment of the invention.
Figure 17B is a flow chart illustrating a method for supplying a dye fixative to a
laundry load according to an embodiment of the invention.
Figure 18 is a flow chart illustrating a method for supplying a dye fixative to a
laundry load according to an embodiment of the invention.
Figure 19 is a flow chart illustrating a method of treating a surface of a laundry
item according to an embodiment of the invention.
Figure 20 is a flow chart illustrating a method for treating a new laundry item according
to an embodiment of the invention.
Figure 21 is a flow chart illustrating a method for treating a new laundry item according
to an embodiment of the invention.
Figure 22 is a flow chart illustrating a method for treating a new laundry item according
to an embodiment of the invention.
Figure 23 is a schematic view of a clothes dryer.
Figure 24 is a schematic view of a controller of the clothes dryer of Figure 23.
Figure 25 is a flow chart illustrating a method for communicating dye transfer information
between a clothes washer and a clothes dryer according to an embodiment of the invention.
Figure 26 is a flow chart illustrating a method for communicating dye transfer information
between a clothes washer and a clothes dryer according to an embodiment of the invention.
Figure 27 is a flow chart illustrating a method for inhibiting dye transfer in a wash
cycle according to an embodiment of the invention.
Figure 28 is a flow chart illustrating a method for removing dye fixative from a laundry
item according to an embodiment of the invention.
Figure 29 is a cross-section, schematic side view of a vertical axis clothes washer
according to an embodiment of the invention.
Figure 30 is a flow chart illustrating a color care cycle of operation according to
an embodiment of the invention.
Figure 31 illustrates a process for supplying a treating chemistry according to an
embodiment of the invention.
Figures 32A and 32B illustrate graphs representative of a change in the liquid level
in a sump of a clothes washer over time during a recirculation process according to
an embodiment of the invention.
Figure 33 illustrates a graph representative of a change in a liquid level in a sump
of clothes washer during an adaptive fill and recirculation process according to an
embodiment of the invention.
Figure 34 illustrates a cross-section, schematic side view of a horizontal axis clothes
washer according to an embodiment of the invention.
Figure 35 illustrates a process for supplying a treating chemistry according to an
embodiment of the invention.
Figure 36 is a cross-section, schematic side view of a vertical axis clothes washer
according to an embodiment of the invention.
Figure 37 is a schematic representation of a controller for controlling the operation
of one or more components of the clothes washer of Figure 36 according to an embodiment
of the invention.
Figure 38 is a flow chart illustrating a cycle of operation for dispensing a treating
chemistry in a pre-wash phase according to an embodiment of the invention.
Figure 39 is a cross-section, schematic side view of a vertical axis clothes washer
in which a treating chemistry is dispensed according to an embodiment of the invention.
Figure 40 is a top-down, schematic view of a vertical axis clothes washer in which
a treating chemistry is dispensed according to an embodiment of the operation.
Figure 41 is a flow chart illustrating a method for implementing a pre-wash phase
according to an embodiment of the invention.
[0016] The embodiments of the invention relate to methods and compositions for inhibiting
undesired dye transfer between fabric items of a laundry load during treatment in
a laundry treating appliance. As used herein, dye transfer is used to refer to the
broader phenomenon of the transfer of a dye from one area of a fabric item to an adjacent
area of the same fabric item that is not dyed with the transferring dye and/or a different
fabric item or surface. Dye transfer may occur through direct physical contact between
the dyed item and another surface or as a result of the dye moving away from the fabric
surface and into solution with a solvent in contact with the fabric surface. Once
the dye has distributed into solution (through suspension, dispersion or solubilization),
the dye may deposit onto other surfaces, including other fabric items, also in contact
with the solution. Dye bleeding is another term of art which, as used herein, refers
to the partitioning of a dye from the surface of a fabric into solution or onto a
differently dyed area of the same fabric. Dye transfer, as used herein, is meant to
be generic to all manner in which dye may move between fabric items or within the
same fabric item. In that sense, dye bleeding is one type of dye transfer. As used
herein, partition is used as the general term to encompass several phenomena including
the distribution of a substance between two immiscible or slightly immiscible phases
based on the relative solubility of the substance within the two phases and the sorption
and desorption of a substance between a solid phase and a surrounding medium or between
two solid phases. The term sorption refers to either absorption in which a substance
distributes within the solid phase or adsorption, the process by which a substance
distributes at the surface of a solid phase.
[0017] Dye transfer between fabric items during laundering in a residential setting may
ruin items in the laundry load to the dissatisfaction of the consumer. One manner
in which dye transfer during a laundry treating cycle of operation in a clothes washer
has been addressed is by separating or sorting laundry loads based on the color of
the items to be washed. For example, typically, clothes washers and laundry detergents
instruct consumers to sort loads and wash items with "like colors," and consumers
may further be instructed to sort laundry into a jeans load, a whites load and a darks
load. Sorting laundry in this manner may be cumbersome for the consumer and a mistake
during sorting, such as accidentally washing a red sock with a load of whites, may
result in undesirable dye transfer between the red sock and the whites, effectively
ruining the whites for the consumer. In addition, sorting loads may be inefficient
as a consumer either has to wait until enough items of a single type are ready for
laundering or run multiple cycles with smaller loads as items become ready for laundering,
with the latter typically leading to more overall water and energy usage.
[0018] Textile producers have developed procedures and chemistries for addressing dye bleeding
and wash fastness of colors during manufacturing that may address dye transfer issues
in the subsequent use of the textile and care of the fabric item made from the dyed
textile. For example, additional washes and rinses can be included in the dyeing process
by the fabric maker to remove excess or loosely bound dyes from the fabric. In addition,
certain treating chemistries may be added to the washes and rinses to facilitate removal
of excess or loose dyes from the fabric. The dyed fabric can also be treated with
a fabric finish to minimize dye bleeding and increase wash fastness. However, the
use and quality of the processes used by different manufacturers can vary significantly.
In a residential setting, when a consumer loads a clothes washer for a laundry cycle,
the consumer usually has no way of knowing whether or not the laundry items have been
treated to minimize dye transfer during a laundry cycle and what the risks of dye
transfer are.
[0019] In an industrial setting the variables of fabric type, dye, and uniformity of material
are known, controlled variables that may be used to determine what processes to implement
to minimize dye bleeding. In a residential setting, these variables are typically
not known and/or controllable. A consumer-loaded clothes washer is not a controlled
setting: the load is likely to be mixture of different fabrics and or colors, with
the exact make-up unknown to the washer. A single garment may have multiple different
fabric types and/or dyes. A consumer may sort the laundry load based on color, but
mix different fabric types, or sort the load based on fabric type, but different dyes
may be present. A consumer is further unlikely to be aware of whether dye transfer
is an issue of concern or whether the items of the laundry load have been treated
so as to minimize dye transfer or the quality of such treatments. Thus, both the design
and implementation of processes and chemistries for minimizing dye transfer in a residential
setting faces many challenges that are not relevant to an industrial setting.
[0020] The methods and chemistries described herein are provided for facilitating laundering
of mixed or unsorted loads of laundry, i.e. loads that include multiple dye types
and/or fabrics, including different fiber types, fabric construction and fabric finishes,
in a domestic clothes washer and clothes dryer. The methods and chemistries described
herein may be used to inhibit dye transfer from one fabric item to another fabric
item during a laundry cycle such that unsorted loads may be laundered with minimal
or no dye transfer between items. Inhibiting dye transfer may include inhibiting partitioning
of the dye away from the fabric surface and/or inhibiting redistribution of the dye
onto another fabric surface. In addition, the methods and chemistries described herein
may also minimize dye transfer from one fabric item to another surface which may come
into contact with the fabric item. It will be understood that unless stated to the
contrary, the methods and chemistries described herein may be utilized interchangeably
even when not explicitly described as such.
[0021] A brief description of the types of chemistries that may be used to facilitate inhibiting
dye transfer and the more commonly used types of dyes may be useful here.
[0022] As used herein a dye transfer inhibitor or dye transfer inhibiting agent is used
to refer to any substance that inhibits dye transfer. The two main groups of dye inhibitors
include dye absorbers and dye fixatives. Dye fixatives are generally molecules that
preferentially partition from solution onto a fabric surface. Most fixatives are high
molecular weight polymers having repeating monomers of either a cationic or anionic
functional group so as to aid in favorable partition onto fabrics through favorable
electrostatic interactions at multiple regions within a fixative molecule and charged
(ionizable) fibers and because large molecules have entropic restraints which inhibit
large molecules from remaining dissolved in an aqueous solution. Dye fixatives may
interact with the fabric surface and form a polymeric film or layer that inhibits
dyes from partitioning away from the fabric surface into solution.
[0023] Dye absorbers are generally molecules that preferentially interact with dye molecules
either through electrostatic interactions or hydrophobic forces (e.g. micelle formation)
to attract dye molecules and suspend the dye molecules in aqueous solution, thus inhibiting
transfer of the dye molecules to another fabric surface. Because most ionic dyes are
anionic in nature, dye absorbers that work through electrostatic interactions are
designed to be cationic in nature in their active state - typically molecules comprising
quaternary or polyamine groups or aromatic pyridine groups. Typically these cationic
polymers are smaller in molecular size compared to dye fixatives to allow them to
remain suspended in solution. In addition, surfactants above the critical micelle
concentration (CMC) may self-assemble into a micelle structure having a hydrophobic
core which can act as a dye absorber by trapping and suspending dye in solution. While
surfactant micelles generally work as dye absorbers for all dye types, they are one
of the few dye absorbers that complex and suspend nonionic disperse dyes. Dye absorbers
can also be from the group of molecules that form host-guest complexes with hydrophobic
molecules, such as cyclodextrin, for example. In general, once the dye absorbers interact
with the dye molecules, the dye absorber-dye molecule complex remains suspended in
solution. In addition to complexing with dyes in solution, dye absorbers may also
preferentially remove loosely held dyes from fabric surfaces and keep them suspended
in solution.
[0024] There are several different types of dyes that are commonly used in dyeing clothing
and other laundry items that vary depending on the type of fiber being dyed. Vat and
sulfur dyes are non-polar, water insoluble pigments with no affinity towards the fabric
fiber, and are commonly used in dyeing jeans and towels. Vatting is a process by which
the solubilized dye enters the cotton and viscose fibers of the fabric and subsequent
oxidation causes the dye to become insoluble in water. Indigo is one of the most common
vat dyes currently used. Vat dyes may present the consumer with several challenges
in caring for items dyed with vat dyes. Improper treatment by the textile manufacturer,
such as failure to remove excess or free dye or improper oxidation, which may result
in dyes that are not fixed to the fabric, may lead to dye transfer in the form of
run-off or bleeding of the dye during washing or when wetted and may also result in
poor rubbing fastness (i.e. dye may transfer to other surfaces, such as other clothing,
furniture or the consumer that the dyed fabric comes into contact with). In addition,
washing of the fabric at high alkalinity may promote removal of dye from the fabric.
Sulfur dyes are another example of vat dyes in which the dye is solubilized, in this
example by reduction in sodium sulfide, and subsequent oxidation renders the sulfur
dye insoluble. Sulfur black is an example of commonly used vat dye. Loose vat dyes
would be dyes that are either unoxidized or present on the surface of the fabrics.
Unoxidized vat dyes are anionic in nature and typically easily partition from cotton
fabrics into an aqueous solution based on their small size and polar nature.
[0025] Disperse dyes are neutral dyes and are typically used for dyeing polyester and acetate
fabrics. Disperse dyes are slightly water soluble dyes that diffuse from solution
into the fibers and remain preferentially dispersed within the fibers due to hydrophobic
interactions between the fibers and the dye. Dispersing agents are utilized to facilitate
dispersion of the dye in the dye bath for dyeing the fabric. In general, and all else
being equal, the greater the molecular weight of the disperse dye, the higher the
wash or color fastness of the dye. As used herein, the term wash fastness is a descriptive
term that refers to the extent to which a dye is retained by the fabric during treatment
of the dyed fabric in a clothes washer. For example, a high degree of wash fastness
refers to a dye that is primarily retained by the fabric and does not bleed or otherwise
transfer during treatment in the clothes washer; a low degree or no wash fastness
refers to a dye that is not retained by the fabric and bleeds or otherwise transfers
during treatment. Typically, only excess or over-dyed fabric presents a dye bleeding
challenge during treatment in a clothes washer. In the case of polyester, only excess
dye molecules that are not associated with the fabric fibers present a potential dye
bleeding problem because the rest of the dye molecules are locked within the polyester
matrix of the fabric, at least below the glass transition temperature of the polyester.
A loose disperse dye is typically a dye that has not entered the crystalline matrix
of the polyester.
[0026] Direct dyes are anionic dyes that typically include a sulfonate group and are used
to dye cotton fibers. Direct dyes interact with cotton fibers primarily through cumulative
London or van der Waal's dispersion forces and hydrophobic forces. Cotton dyed with
direct dyes are often treated with post-processing techniques such as treatment with
a dye fixative or treatment to remove loosely attached dye to address dye bleeding
and wash fastness. The anionic (e.g. sulfonate) group of direct dyes has a small cationic
counterion (typically sodium) and if dye exhaustion is not done well, the sodium ion
can dissociate from the dye in an aqueous wash solution, resulting in the direct dye
being deprotonated and hence hydrophilic, which can lead to bleeding in an aqueous
wash liquor. In addition, certain types of surfactants may interrupt the interaction
between the cotton fibers and the dye molecules, which may lead to an increase in
dye bleeding. In addition, because the interaction between direct dyes and cotton
is based on non-permanent, weak molecular interactions, water and mechanical action
may also increase dye bleeding. Loose direct dyes are typically dyes that are not
exhausted well with NaCI (suggesting there are dissociable Na counter-ions left) or
not rinsed off well.
[0027] Acid dyes are anionic dyes that include a sulfonate group, similar to direct dyes,
but are typically smaller than direct dyes. Acid dyes are usually used to dye nylon,
wool and silk fibers, with the negatively charged sulfonate group of the dye interacting
with the positively charged amide in the nylon at a low pH where the amide group in
nylon is in a protonated form. Typically, nylon is heated above its glass transition
temperature (about 40 °C for Nylon 6.6.) to promote penetration of the acid dye molecules
into the fabric during dyeing. The nylon is cooled at the end of the dyeing process
to lock the dyes within the nylon. Even though the interaction between the dye and
the fiber is an electrostatic interaction, the crystalline nylon matrix may prevent
dye bleeding of adhered dye molecules, even during a subsequent increase in pH (e.g.
during laundering). However, there is the potential for over-dyeing of the nylon after
the cationic nylon fiber sites are exhausted. In addition, dyed nylon may have lower
wash fastness in the presence of certain surfactants, such as a linear alkylbenzene
sulfonates (LAS), which has a similar sulfonate group to the dye molecules, and is
more surface active than the acid dye and some other types of surfactants and thus
may have a greater potential to displace loose dyes from the nylon surface. A loose
acid dye is typically a dye that has not entered the crystalline matrix of the nylon.
[0028] Reactive dyes are dyes that covalently bond to fabric fibers through reactive sites
on the fibers, the most common being cotton fibers. Once the dye molecule reacts with
the cotton fiber, the dye is completely wash fast. However, during the dyeing process,
competing reactions may result in hydrolysis of the dye molecule reactive group, leaving
a dye molecule that may interact with and be carried by the cotton fibers, but is
no longer capable of covalently bonding with the fibers. Failure to adequately remove
un-reacted dyes from the cotton fiber matrix may result in loose dye molecules that
may bleed in a subsequent laundry process.
[0029] Referring now to Figure 1, an exemplary method for treating a laundry load according
to a dye transfer inhibition wash cycle 10 is illustrated. While the methods described
herein will be discussed in the context of a mixed load of laundry, i.e. an unsorted
load of laundry that is not uniform in at least one of fabric type and fabric dye
color, it will be understood that it is within the scope of the invention for the
methods to also be used with sorted laundry loads. In addition, it will be understood
that the sequence of steps depicted is for illustrative purposes only, and is not
meant to limit the methods described herein in any way as it is understood that the
steps may proceed in a different logical order, additional or intervening steps may
be included, or described steps may be divided into multiple steps, without detracting
from the invention. Furthermore, while the wash cycle 10 is described in the context
of inhibiting dye transfer, it will be understood that individual phases of the wash
cycle 10 and the additional methods described herein may also be used for additional
purposes, such as facilitating distribution of a treating chemistry, for example.
[0030] As used herein, the term wash liquid refers to a combination of water and at least
one treating chemistry for providing detergency to lift soils from the laundry, and
may also include other treating chemistries. Laundry soils may refer to dirt, oils,
and stains, such as may be caused by food, dyes, beverages, environmental soil, or
bodily fluids, for example. The term rinse liquid or rinse water refers to any liquid
used to rinse away a treating chemistry and may include water with one or more treating
chemistries or just water. The wash liquid may be just water, in which case it may
be referred to as a rinse water or water. The term treating liquid is a generic term
that refers to a combination of water and at least one treating chemistry, which may
refer to a wash liquid, a rinse liquid or any other liquid having at least one treating
chemistry. The terms recirculated liquid and recirculated water refer to water or
a combination of water and one or more treating agents that is pumped from a collection
area and re-applied to the laundry, with or without the addition of additional water
from the household water supply. As used herein, the term liquid is generic, and includes
all types of liquid, including without limitation wash liquid, rinse liquid, rinse
water, water, recirculated liquid, etc.
[0031] Supplying or applying liquid to the laundry may be done in any desired manner, such
as, without limitation, directly and/or indirectly, and may be done as pouring, spraying
or misting. The supplying of liquid will typically be into the treating chamber in
which the laundry is located from a water supply or dispenser and/or supplying a water
or a treating chemistry to a collection area from which the liquid is then pumped
and either sprayed or misted into the treating chamber. In addition, when laundry
is located within a rotatable drum within a tub, supplying or applying a liquid may
also include supplying liquid to the tub and rotating the drum such that the laundry
within the drum rotates through the liquid in the tub.
[0032] The dye transfer prevention wash cycle 10 may begin with an optional pre-wetting
phase 12 in which the laundry may be pre-wetted with a liquid. A pre-wash phase 14
may include treating the laundry load with a treating chemistry, an exemplary embodiment
of which includes a dye fixative. A main wash phase 16 may include washing the laundry
with a detergent-based laundry composition and optionally treating the laundry with
an additional treating chemistry, such as a dye absorber. At rinse phase 18 the laundry
load may be treated with a fabric softener and additional dye absorber followed by
an extraction phase at 20, which may include spinning the laundry at high speeds to
remove extraneous liquid from the laundry load. The wash cycle 10 may also include
an optional laundry load detection phase 22.
[0033] The pre-wetting phase 12 may include wetting the laundry load with a limited amount
of liquid before applying a treating chemistry at 14. The liquid may be any treating
liquid or water from the water supply without any additional substances added to the
water. While the pre-wetting phase 12 is generally described in the context of pre-wetting
with water without any additional substances added to the water by the clothes washer,
it will be understood that the pre-wetting phase 12 may be implemented in a similar
manner with a treating liquid including a treating chemistry.
[0034] The liquid may be applied to the laundry at a predetermined rate for a predetermined
period of time while the laundry is being rotated within the treating chamber. Liquid
may be added during the pre-wetting phase 12 to wet the laundry to promote distribution
of the treating chemistry in the subsequent pre-wash phase 14 without adding too much
liquid such that dye transfer occurs. In one example, the liquid supplied during the
pre-wetting phase 12 may be just water; in another example, the liquid may include
an emulsion to make the surface of the laundry hydrophobic to facilitate distribution
of a subsequently supplied treating chemistry, such as a dye fixative. In addition,
the pre-wetting phase 12 may be used in a similar manner to pre-wet the laundry prior
to the main wash phase 16 if there is no pre-wash phase 14. If too much liquid is
added, loose dye may partition into the liquid and may transfer to other items in
the load as the liquid distributes through the load. If too much liquid is added,
whether the laundry is saturated or not, the liquid with the loose dyes may also run
off of one laundry item to another and effect dye transfer. Therefore, the pre-wetting
phase 12 is not intended to saturate the laundry or have liquid run off. If the load
is agitated or spun at too high of a speed, such as speeds corresponding to a force
of 1 G for that particular drum, dye transfer could occur between laundry items.
[0035] In addition, while the laundry may be rotated or re-oriented during the pre-wetting
phase 12 to distribute the liquid added during the pre-wetting phase 12, too much
agitation of the laundry or spinning the laundry at too high of a speed may facilitate
dye transfer between laundry items. While not meant to be limited by any theory, it
is believed that pre-wetting the laundry with liquid prior to the application of the
dye fixative may facilitate more uniform distribution of the dye fixative on the fabrics
by lowering interfacial driving forces and reducing a rate of fabric penetration and/or
a rate of attachment of the dye fixative. The pre-wetting may also facilitate the
distribution of additional treating chemistries other than dye fixatives, such as
a laundry detergent or fabric softener, for example.
[0036] During the pre-wetting phase 12, the dry laundry (i.e. laundry that has not been
previously wet by the clothes washer during the present cycle of operation) may be
wet with liquid while the laundry is rotating at a low speed, passing through a fogging
or misting spray nozzle, as will be described in more detail below. Exemplary rotation
speeds include 20-60 rpm, but preferably may be within the range of 20-30 rpm. As
used herein, the terms mist and fog are interchangeable and refer to a phenomenon
in which liquid is sprayed in droplets having a diameter and spray rate at which the
droplets will be temporarily suspended in air until they collide or condense on a
surface, coalesce to form water droplets that are too larger to remain suspended in
air and fall due to gravity, or evaporate to form a vapor. The spray nozzle may be
configured to spray the mist as fine droplets, on the order of 10 to 100 microns in
diameter, which become suspended in air and remain suspended in air as the droplets
slowly settle onto the laundry load. The spray nozzle may be configured to use very
little liquid, for example, less than 500 mL/min., such that the mist that settles
on the laundry is absorbed onto the surface of the laundry that it comes into contact
with, but the volume of liquid is not such that the liquid "runs off' the laundry.
The liquid may be sprayed onto the laundry during the pre-wetting phase 12 while the
laundry is rotating at a similar speed to the speed the drum rotates during the pre-wash
phase 14 such that generally the same areas of the laundry wet during the pre-wetting
phase 12 may also be wet during the pre-wash phase 14. It has been found that wetting
the laundry in this manner with very little liquid improves the distribution of a
treating chemistry, such as a dye fixative, that may be supplied in the subsequent
phase, such as the pre-wash phase 14, or the main wash phase 16 if there is not a
pre-wash phase, by a measurable amount.
[0037] While the pre-wash phase 14 is described as being subsequent to the pre-wetting phase
12, it will be understood that the pre-wash phase 14 may occur contemporaneously with
the pre-wetting phase, meaning the pre-wetting phase 12 and the pre-wash phase 14
may occur over the same period of time or at least partially overlap. In one example,
the pre-wash phase 14 may be initiated at some delayed time after a start of the pre-wetting
phase 12 such that the pre-wash phase 14 occurs during at least a portion of the same
time as the pre-wetting phase 12. In another example, the pre-wetting phase 12 and
pre-wash phase 14 may be alternately repeated two or more times before proceeding
to the next phase in the cycle.
[0038] Figure 2A illustrates a laundry treating appliance in the form of a vertical axis
clothes washer 50 which may be used to implement a cycle of operation, such as the
dye transfer prevention wash cycle 10. While the embodiments of the invention are
described in the context of a clothes washer, it will be understood that many of the
embodiments are applicable to any laundry treating appliance, such as a clothes dryer
or combination clothes washer/dryer, for distributing a treating chemistry and inhibiting
dye transfer.
[0039] The clothes washer 50 includes a cabinet or housing 52 and an imperforate tub 54
that defines an interior 56 of the washing machine 50. A sump 58 may be in fluid communication
with the interior 56 of the tub 54. A perforated wash basket or drum 60 may be located
within the interior 56 and rotatable relative to the tub 54 and may define a laundry
treating chamber 62 for receiving a laundry load. Rotation of the drum 60 may be considered
as rotation of any items located within the treating chamber 62. The drum 60 may include
a plurality of perforations or apertures (not shown) such that liquid supplied to
the drum 60 may flow through the perforations to the tub 54. An agitator or clothes
mover 64 may be located within the laundry treating chamber 62 and rotatable relative
to and/or with the drum 60. While the embodiments of the invention are described in
the context of a clothes washer having a rotatable drum located within a tub, it will
be understood that the embodiments may also be used in a clothes washer which has
an imperforate drum without a tub.
[0040] The drum 60 and/or the clothes mover 64 may be driven by an electrical motor 66,
which may or may not include a gear case, operably connected to the drum 60 and/or
the clothes mover 64. The clothes mover 64 may be commonly oscillated or rotated about
its axis of rotation during a cycle of operation in order to provide movement to the
fabric load contained within the laundry treating chamber 62. The drum 60 may be rotated
at high speed to centrifugally extract liquid from the fabric load and to discharge
it from the drum 60. The top of the housing 52 may include a selectively openable
lid 68 to provide access into the laundry treating chamber 62 through an open top
of the drum 60.
[0041] Still referring to Figure 2A, a spraying system 70 may be provided to spray liquid,
such as water or a combination of water and one or more treating chemistries into
the open top of the drum 60 and onto laundry placed within the laundry treating chamber
62. Non-limiting examples of treating chemistries that may be dispensed by the dispensing
system during a cycle of operation include one or more of the following: water, surfactants,
detergents, enzymes, fragrances, stiffness/sizing agents, wrinkle releasers/reducers,
softeners, antistatic or electrostatic agents, stain repellants, water repellants,
energy reduction/extraction aids, antibacterial agents, medicinal agents, vitamins,
moisturizers, shrinkage inhibitors, dye fixatives, dye absorbers, bleaches and combinations
thereof.
[0042] The spraying system 70 may be coupled with a treating chemistry dispensing system
(not shown) to supply the treating chemistry alone or mixed with water from the water
supply 72 to the laundry. The dispensing system may include a dispenser which may
be a single use dispenser, a bulk dispenser or a combination of a single use and bulk
dispenser. Non-limiting examples of suitable dispensers are disclosed in
U.S. Patent. No. 8,196,441 to Hendrickson et al., issued June 12, 2012, entitled "Household Cleaning Appliance with a Dispensing System Operable Between
a Single Use Dispensing System and a Bulk Dispensing System,"
U.S. Patent No. 8,388,695 to Hendrickson et al., issued March 5, 2013, entitled "Apparatus and Method for Controlling Laundering Cycle by Sensing Wash
Aid Concentration,"
U.S. Patent No. 8,397,328 to Hendrickson et al., issued March 19, 2013, entitled "Apparatus and Method for Controlling Concentration of Wash Aid in Wash
Liquid,"
U.S. Pub. No. 2010/0000581 to Doyle et al., filed July 1, 2008, entitled "Water Flow Paths in a Household Cleaning Appliance with Single Use and
Bulk Dispensing,"
U.S. Pub. No. 2010/0000264 to Luckman et al., filed July 1, 2008, entitled "Method for Converting a Household Cleaning Appliance with a Non-Bulk Dispensing
System to a Household Cleaning Appliance with a Bulk Dispensing System,"
U.S. Patent No. 8,397,544 to Hendrickson, issued March 19, 2013, entitled "Household Cleaning Appliance with a Single Water Flow Path for Both Non-Bulk
and Bulk Dispensing," and
U.S. Patent No. 8,438,881, issued May 14, 2013, entitled "Method and Apparatus for Dispensing Treating Chemistry in a Laundry Treating
Appliance".
[0043] The dispensing system may also include a system for determining information related
to the treating chemistry supplied to the dispensing system and communicating the
information with the controller 82. In one example, information related to the treating
chemistry may be determined directly using one or more sensors, non-limiting examples
of which include a chemical sensor, a pH sensor, or a UV/VIS absorbance or fluorescence
sensor. In another example, information related to the treating chemistry may be carried
by a container storing the treating chemistry that may be communicated wirelessly
with the clothes washer controller 82 (e.g. through an RFID system) or through a hard-wire
connection. In another example, the clothes washer may include an optical-based communication
system, such as a bar code reader and bar code for communicating information related
to the treating chemistry. Non-limiting examples of information related to the treating
chemistry that may be supplied to the controller 82 include an identity or characteristic
of the treating chemistry or one or more components of the treating chemistry; dosage
information, such as concentration or amount; dispensing information, such as an amount,
concentration, time to dispense, or a number of times to dispense; and cycle usage
information, such as what cycle, phase or stage to dispense the treating chemistry.
In yet another example, the user may enter information related to the treating chemistry
using the user interface 84. The exact manner by which information related to the
treating chemistry supplied to the dispensing system is provided to the controller
82 is not germane to the embodiments of the invention.
[0044] The spraying system 70 may be configured to supply water directly from a household
water supply 72 and/or from the tub 54 and spray it onto the laundry through a sprayer
74. The spraying system 70 may also be configured to recirculate wash water from the
tub 54, including the sump 58, and spray it onto the laundry. The spraying system
70 may also include additional sprayers and other components to supply liquid to one
or more additional locations, such as a portion of the interior 56 between the drum
60 and the tub 54, an exterior surface of the drum 56, an interior surface of the
drum 56 and an internal surface of the tub 54. The nature of the spraying system is
not germane to the invention, and thus any suitable spraying system may be used with
the laundry treating appliance 50.
[0045] A pump 76 may be housed below the tub 54. The pump 76 may have an inlet fluidly coupled
to the sump 58 and an outlet configured to fluidly couple to either or both a household
drain 78 or a recirculation conduit 80. In this configuration, the pump 76 may be
used to drain or recirculate liquid in the sump 58, which is initially sprayed into
the treating chamber 62, flows through the drum 60, and then into the sump 58. Alternatively,
two separate pumps may be used instead of the single pump as previously described.
[0046] The washing machine 50 also includes a control system for controlling the operation
of the washing machine 50 to implement one or more cycles of operation. The control
system may include a controller 82 located within the cabinet 52 and a user interface
84 that is operably coupled with the controller 82. The user interface 82 may include
one or more knobs, dials, switches, displays, touch screens and the like for communicating
with the user, such as to receive input and provide output. The user may enter different
types of information including, without limitation, cycle selection and cycle parameters,
such as cycle options.
[0047] The controller 82 may include the machine controller and any additional controllers
provided for controlling any of the components of the washing machine 50. For example,
the controller 82 may include the machine controller and a motor controller. Many
known types of controllers may be used for the controller 82. The specific type of
controller is not germane to the invention. It is contemplated that the controller
82 is a microprocessor-based controller that implements control software and sends/receives
one or more electrical signals to/from each of the various working components to effect
the control software. As an example, proportional control (P), proportional integral
control (PI), and proportional derivative control (PD), or a combination thereof,
a proportional integral derivative control (PID control), may be used to control the
various components.
[0048] As illustrated in Figure 3, the controller 82 may be provided with a memory 96 and
a central processing unit (CPU) 98. The memory 96 may be used for storing the control
software that is executed by the CPU 98 in completing a cycle of operation using the
washing machine 50 and any additional software. Examples, without limitation, of cycles
of operation include: wash, heavy duty wash, delicate wash, quick wash, pre-wash,
refresh, rinse only, timed wash and any of the cycles of operation described herein.
The memory 96 may also be used to store information, such as a database or table,
and to store data received from one or more components of the washing machine 50 that
may be communicably coupled with the controller 82. The database or table may be used
to store the various operating parameters for the one or more cycles of operation,
including factory default values for the operating parameters and any adjustments
to them by the control system or by user input.
[0049] The controller 82 may be operably coupled with one or more components of the washing
machine 50 for communicating with and controlling the operation of the component to
complete a cycle of operation. For example, the controller 82 may be operably coupled
with the motor 66, the pump 76, the sprayer 74, and any other additional components
that may be present such as a steam generator, a treating chemistry dispenser, and
a sump heater (not shown) to control the operation of these and other components to
implement one or more of the cycles of operation.
[0050] The controller 82 may also be coupled with one or more sensors 99 provided in one
or more of the systems of the washing machine 50 to receive input from the sensors
99, which are known in the art and not shown for simplicity. Non-limiting examples
of sensors 99 that may be communicably coupled with the controller 82 include: a treating
chamber temperature sensor, a moisture sensor, a weight sensor, a chemical sensor,
an optical sensor, a conductivity sensor, a turbidity sensor, a position sensor and
a motor torque sensor, which may be used to determine a variety of system, laundry
and liquid characteristics, such as laundry load inertia or mass.
[0051] Still referring to Figure 2A, the sprayer 74 may be controlled during the pre-wetting
phase 12 to spray a mist or fog of water or other treating chemistry into the treating
chamber 62 to wet a load of laundry 86. In a vertical axis clothes washer, liquid
sprayed into the treating chamber62 will come from above the laundry load 86 through
the open top of the drum 60. During spraying, an exposed, upper surface of the laundry
load 86 will be contacted first by liquid sprayed from the sprayer 74. With continued
spraying from the sprayer 74, liquid may travel through and around the exposed, upper
surface of the load 86 to other surfaces of the load 86. The exposed, upper surface
of the laundry load 86 may be referred to as a first strike surface 88 for liquid
sprayed from the sprayer 74.
[0052] The controller 82 may be configured to determine a dye transfer event. The controller
82 or a communication module located therein or operably coupled thereto may be configured
to output a communication that a dye transfer event has occurred. For example, such
a communication may be outputted to a dryer. It will be understood that the communication
may be a wireless communication and/or a hard-wired communication.
[0053] During the pre-wetting phase 12, the laundry may be rotated while the sprayer 74
sprays water or a mixture of water and a treating chemistry into the treating chamber
62 to wet the first strike surface 88. Rotating the laundry may include rotating the
drum 60 or actuating the clothes mover 64 to move the laundry. It is also within the
scope of the invention for the sprayer 74 to rotate relative to the laundry. The sprayer
74 may be controlled so as to wet the first strike surface 88 without over-wetting
the laundry 86 such that the amount of water that travels from one fabric surface
to another is minimized. As described above, if too much water is sprayed onto the
load 86, loose dye from fabrics forming the load 86 may partition into the water and
may transfer to other items in the load 86. The sprayer 74 may spray the water as
a mist or fog of fine water droplets configured to be suspended in the air when sprayed
and slowly settle down onto the exposed surface of the laundry, i.e. the first strike
surface 88, to facilitate covering all of the first strike surface area 88 while minimizing
the volume of water used. For example, as described above, the sprayer 74 may be configured
to spray the mist as fine droplets, on the order of 10 to 100 microns in diameter,
at a rate less than 500 mL/min., which uses very little water, but enough such that
the mist that settles on the laundry is absorbed onto the surface of the laundry.
[0054] The application of the liquid during the pre-wetting phase 12 as a mist allows the
liquid to be supplied to the laundry at a volume, droplet size and rate such that
the liquid may be absorbed onto the laundry surface without running off the surface.
If the liquid is sprayed at a larger volume, droplet size and/or rate, the liquid
may reach the laundry surface at too high a volume and/or rate to be entirely absorbed
by the impacted laundry surface and thus some of the liquid may run off the surface,
potentially transferring dye from the impacted laundry surface to another surface
the liquid run-off comes into contact with.
[0055] In one example, an amount of liquid supplied to the laundry as a mist during the
pre-wetting phase 12 may be an amount that wets the laundry to a predetermined remaining
moisture content (RMC). As used herein, RMC is defined as the ratio of an amount of
water in the fabric in addition to the natural regain moisture of the fabric to the
amount of fabric. The natural regain moisture of a fabric is based on the natural
amount of moisture in the fabric at dry conditions and is considered zero water or
zero RMC. The RMC for the pre-wetting phase may range between 5-40% and in an exemplary
embodiment is within the range of 10-20%. It will be understood that wetting the laundry
to a predetermined RMC does not mean that all fabrics in the load would have to be
wet to the predetermined RMC. In one example, the clothes washer 50 may determine
the load amount and then the sprayer 74 may be controlled by the controller 82 to
spray an amount of liquid based on a predetermined RMC for the determined load amount.
The amount of laundry may be determined according to any suitable method, including
the methods described herein. It will be understood that the method by which the amount
of laundry is determined is not germane to the embodiments of the invention.
[0056] The drum 60 may also be rotated to facilitate even coverage of the first strike surface
88 with the mist from the sprayer 74. The drum 60 may be rotated at a relatively low
speed, for example, 20-60 rpm or less than 1 G, for example, to avoid agitating the
load 86. In addition to facilitating dye transfer, agitating the laundry load 86 or
spinning the laundry load 86 at too high of a speed too quickly may cause the load
items to move relative to one another within the treating chamber 62 such that a different
fabric surface is exposed, which may result in exposing un-wetted laundry as the first
strike surface 88 when a treating chemistry is sprayed onto the load 86 during a subsequent
phase. Pre-wetting the first strike surface 88 prior to application of the treating
chemistry facilitates distribution of the treating chemistry through the laundry load
86. If the treating chemistry is sprayed onto a dry fabric surface, the treating chemistry
may not distribute through the load 86 within a reasonable period of time. In the
exemplary embodiment of a dye fixative, there is typically an electrostatic attraction
between the dye fixative and the fabric substrate which may lead to localized spots
of high concentration of dye fixative where the dye fixative first comes into contact
with the fabric surface. Pre-wetting the fabric may slow the formation of electrostatic
bonds between the dye fixative and the fabric surface such that the dye fixative may
distribute more readily across the fabric surface.
[0057] Following the pre-wetting of the first strike surface 88 during the pre-wetting phase
12 and the subsequent wetting of the laundry with a treating chemistry, such as a
dye fixative, in the pre-wash phase 14, the laundry may be re-oriented to expose at
least a portion of a previously unexposed surface. Redistribution of one or more of
the items of the laundry load 86, such as by movement or reorientation of at least
one load item relative to another load item or the drum 60, may result in a previously
unexposed portion of the laundry surface being present at the first strike surface
88. The addition of at least a portion of a previously unexposed surface or exchange
of at least a portion of a previously unexposed surface for a recently exposed surface
at the first strike surface 88 may be considered a new exposed surface. As used herein,
a new exposed surface refers to a surface in which at least a portion of the surface
is formed from a previously unexposed surface. Exposing a new surface may include
rotating the drum 60 to re-orient the laundry and/or actuating the clothes mover 64.
[0058] The pre-wetting phase 12 and pre-wash phase 14 may be repeated one or more times
to expose a new surface, pre-wet the new surface with a pre-wetting mist and then
treat the pre-wet surface of the laundry with a dye fixative or other treating chemistry
to facilitate a uniform distribution of the treating chemistry on the laundry, while
decreasing the likelihood of dye transfer. It is also within the scope of the invention
for the pre-wetting phase 12 to include spraying a mist onto a first exposed surface
and then re-orienting the laundry to expose a previously unexposed portion of the
laundry and spraying a mist onto the new expose surface one or more times prior to
supplying the treating chemistry in the pre-wash phase 14.
[0059] Referring again to Figure 1, the dye transfer prevention wash cycle 10 may include
an optional load detection phase 22 which may occur prior to or as part of the pre-wetting
phase 12. The load detection phase 22 may be used to determine an amount of laundry
present in the treating chamber 62. The amount of laundry may be qualitative or quantitative
and may be determined manually based on user input through the user interface 84 or
automatically by the washing machine 50. For example, a qualitative determination
of the laundry amount may include determining whether the laundry is a small, medium
or large load. A quantitative determination may include determining a weight or volume
of the laundry within the treating chamber 62.
[0060] The amount of laundry may be determined at 22 according to any suitable method for
determining the amount of laundry prior to the addition of liquid to the laundry treating
chamber. One example of a suitable method for automatically determining the amount
of laundry prior to the application of liquid may include using a weight sensor coupled
with the tub 54. Another example of a suitable method may include rotating the drum
60 with the motor 66 and using feedback from the motor or one or more sensors associated
with the motor 66 or the drum 60 to determine the amount of laundry. One example of
determining the amount of laundry by rotating the drum 60 with laundry therein is
disclosed in
U.S. Pub. No. 2011/0247148 to Chanda et al., filed April 12, 2011, entitled "Laundry Treating Appliance with Load Amount Detection". Additional exemplary
methods include
U.S. Pub. U.S. Patent No. 8,176,798 to Ashrafzadeh et al., issued May 15, 2012, entitled "Method and Apparatus for Determining Laundry Load",
U.S. Patent No. 8,381,569 to Lilie et al., issued February 26, 2013, entitled "Method and Apparatus for Determining Load Amount in a Laundry Treating
Appliance,"
U.S. Patent No. 8,166,590 to Ashrafzadeh et al., issued May 1, 2012, entitled "Method and Apparatus for Determining Laundry Load Size," and
U.S. Patent No. 8,215,134 to Ashrafzadeh et al., issued July 10, 2012, entitled "Method and Apparatus for Determining Laundry Load Size". As discussed
above, the addition of too much liquid to the laundry 86 may facilitate dye transfer
between laundry items and thus methods for determining the amount of laundry that
do not require the addition of saturating amounts of liquid to the laundry may be
preferred.
[0061] Referring now to Figure 2B rotation of the drum 60 during the laundry load detection
phase 22 may shift the laundry load 86 within the treating chamber 62 such that the
laundry spreads out and forms a depression ring around the clothes mover 64. In general,
the movement of the load items relative to each other is minimal during the shift
of the load to minimize dye transfer that may occur from frictional contact between
load items during movement of one load item relative to another. The shifting of the
laundry to form the depression ring may increase the surface area of the first strike
surface 88 that is exposed during the pre-wetting phase 12 and the pre-wash phase
14. In one example, the pre-wetting phase 12 may coincide with the laundry load detection
phase 22 such that the first strike surface 88 is wetted as the laundry load 86 shifts
about the clothes mover 64. In general, laundry items that are placed into the drum
60 by a user prior to the start of a cycle of operation are typically piled on top
of each other within the treating chamber 62 around and possibly over the clothes
mover 64, providing a generally "flat" first strike surface 88, such as is illustrated
in Figure 2A. As the drum 60 is rotated at low speed, the laundry 86 may move from
the generally flat distribution illustrated in Figure 2A to the depression ring illustrated
in Figure 2B.
[0062] Figure 4 illustrates a method 100 for supplying a treating chemistry while determining
the amount of laundry that may be used with the wash cycle 10 or with any other suitable
method, including those further described herein. While the method 100 is described
in the context of combining the load detection phase 22 and the pre-wetting phase
12 of wash cycle 10, the method 100 may also be used in a similar manner to combine
the load detection phase 22 with the pre-wash phase 14. Inertia-based load amount
determination methods, such as that described in
U.S. Pub. No. 2011/0247148 to Chanda et al., for example, typically use motor torque information when the drum is rotated according
to a predetermined drum rotation profile to determine the inertia of the system and
use the determined inertia of the system to estimate the amount of laundry in the
drum. These types of inertia-based methods generally utilize information already available,
i.e. the motor torque, without the use of additional sensors, such as weight sensors,
for example.
[0063] The method 100 utilizes the shifting of the laundry during the rotation of the drum
according to an inertia-based load amount determination to facilitate distributing
a treating chemistry onto the laundry, such as water during the pre-wetting phase
12 or a dye fixative during the pre-wash phase 14 of wash cycle 10, for example. The
method 100 begins with assuming that a user has loaded the laundry into the treating
chamber and selected a cycle of operation. At 102, a treating liquid may be supplied
to the laundry in the treating chamber. This may include spraying the treating liquid
into the treating chamber, such as through the sprayer 74 of clothes washer 50, for
example.
[0064] At 104, the drum may be rotated according to the load amount determination method.
Rotation of the drum may coincide with the supplying of the treating liquid at 102.
The drum 60 may begin to rotate simultaneously with the supply of the treating liquid
at 102 or at some delayed time after the start of the supplying of the treating liquid.
The treating liquid may be supplied continuously or intermittently as the drum 60
is rotated during the load determination at 106. At 108, the load amount determination
may end and the supply of treating liquid to the laundry may end at 110. The load
amount determination 108 and supply of treating liquid at 110 may end simultaneously
or sequentially.
[0065] As described with respect to Figures 2A and 2B above, as the drum 60 is rotated,
the laundry 86 may shift within the treating chamber 62, increasing the first strike
surface 88. Supplying the treating liquid as the laundry 86 shifts from the initial
orientation shown in Figure 2A to the orientation the laundry 86 assumes after rotating,
illustrated in Figure 2B, may increase the surface area of the laundry that is contacted
by the treating liquid as the treating liquid may contact the laundry surface exposed
in the initial orientation, the orientation after rotating, and the transitional orientations
in between. In addition, performing the load amount determination and the supply of
the treating liquid coincidentally rather than sequentially can save cycle time. Furthermore,
if the treating liquid is not added until after the load determination, the initially
exposed fabric surfaces and the transitional fabric surfaces may not be covered by
the treating liquid.
[0066] The amount of treating liquid supplied at 102 and 106 may be a small, known amount
of liquid that may facilitate the load amount determination and also facilitate uniform
distribution of the liquid onto the laundry. The amount of treating liquid may be
far below an amount that would saturate the laundry load but is sufficient to just
dampen the laundry, while minimizing the potential for liquid run-off from the laundry.
For example, if the load amount has been determined, the amount of treating liquid
may be between 5-10% of the load amount. Alternatively, the amount of treating liquid
may be between 50-150 mL, which is likely to be sufficient to provide a layer of liquid
on the exposed fabric surface, irrespective of load size. The treating liquid may
further be applied as a mist, as described above, to facilitate a more uniform distribution
of the liquid. While not meant to be limited by any theory, it is believed that the
addition of a small volume of relatively uniformly applied liquid may provide additional
mass to the laundry which increases the forces compressing the laundry around the
periphery of the drum and provides for a more predictable distribution of the laundry
within the drum, which may improve the accuracy of the inertia-based load amount determination.
In addition, as described above with respect to the pre-wetting phase 12 of the cycle
10, pre-wetting the laundry with a small amount of a fine mist of water without saturating
the laundry may facilitate distribution of a subsequently applied treating chemistry
while minimizing the dye transfer that may occur if too much liquid is added.
[0067] Following the end of the supply of the treating liquid at 110, an optional extraction
phase may be implemented in which the laundry is spun at a predetermined rate for
a predetermined period of time to provide a relatively consistent liquid-to-cloth
ratio to facilitate the load estimation. Alternatively, the additional mass provided
by the added liquid may be subtracted from the load amount estimation if the effect
of the additional mass is deemed significant enough to have impacted the outcome of
the load amount estimation.
[0068] As discussed above, it is within the scope of the invention for the laundry load
detection phase 22 and the pre-wetting phase 12 to be performed sequentially or simultaneously.
Because the pre-wetting phase 12 does not saturate the laundry load 86 to a substantial
degree, the amount of water added during the pre-wetting phase 12 is generally not
considered to significantly effect the load amount determination. Thus, the laundry
load detection phase 22 and the pre-wetting phase 12 may overlap to save cycle time
without negatively effecting the laundry load detection. While the method 100 is described
in the context of determining the amount of laundry while supplying a treating chemistry,
it will be understood that the rotation of the drum 104 may be implemented without
determining an amount of laundry. In addition, it is also within the scope of the
invention for the treating chemistry to only be supplied to the shifted laundry at
the end of the load amount determination.
[0069] Referring now to Figure 5, a method 120 for applying a treating chemistry is illustrated.
While the method 120 is described in the context of applying a dye fixative, it will
be understood that the method 120 may also be used to apply other treating chemistries.
The dye fixative application method 120 may be used as part of the cycle 10 to apply
a dye fixative during the pre-wash phase 14, or as a separate cycle or part of another
cycle. The method 120 may begin at 122 with forming a dye fixative solution. The dye
fixative solution may include one or more dye fixatives and optional adjuncts, such
as a solvent (e.g. water) and a viscosity modifier, for example. Forming the dye fixative
solution may include providing a ready-to-use dye fixative solution to a dispenser
fluidly coupled with the sprayer 74. Alternatively, the dye fixative solution may
be mixed with water or other treating liquid in a suitable mixing chamber or in the
sump 58 prior to providing the dye fixative solution to the sprayer 74. At 124, a
first portion of the dye fixative solution formed at 122 may be sprayed onto the first
strike surface 88 that has been pre-wetted with water as described above with respect
to the pre-wetting phase 12 of the cycle 10. The dye fixative may be applied at 124
while the drum 60 is rotating at speeds where the resulting centrifugal force acting
on the laundry is below 1 G, which, for short-hand reference, will be referred to
as rotating at a speed less than 1G or similar language. Similarly, rotating at a
speed where the resulting centrifugal force acting on the laundry is above 1 G, will
be referred to as rotating at a speed above 1G or similar language.
[0070] Following application of the first portion of the dye fixative solution to the first
strike surface 88 at 124, the remainder of the dye fixative solution may continue
to be supplied into the treating chamber 62 through the sprayer 74 as the drum 60
continues to rotate to distribute the dye fixative through the laundry load 86. In
one example, the drum 60 may be rotated at increasing speeds below 1 G from 20-60
rpm to facilitate downward flow of the dye fixative through the laundry load 86. The
drum 60 may then be spun at increasing speeds above 1 G from 50-120 rpm, for example,
to facilitate flow of the dye fixative laterally through the laundry load 86. All
exemplary rotational speeds provided in this disclosure are for a basket or drum having
a radius of 11 inches (28 cm). As centrifugal force is a function of the radial distance
from the axis of rotation to the center of gravity of the laundry item, speed alone
is insufficient to define the centrifugal force. It will be understood that the rotational
speeds may be adjusted based on the radius of the basket or drum without deviating
from the scope of the invention.
[0071] While not meant to be limited by any theory, it has been observed that as the laundry
is wetted with water or a treating chemistry, flow channels form within the laundry
as the liquid distributes through the load. The flow channels are formed by the movement
of the liquid through the laundry and do not necessarily correspond to gaps within
the laundry. Once the flow channels are established, it may become difficult to wet
regions of the laundry outside these established flow channels. Typically, the limitations
of the flow channels may be overcome by repositioning the laundry, such as by agitation,
for example, in which the laundry items move relative to one another. However, in
cases where dye transfer is of concern, the mechanical action from inducing relative
movement between laundry items of the load at this stage may facilitate dye transfer.
Rotating the laundry at speeds below 1 G to initially distribute the dye fixative
and then increasing the speed above 1 G may facilitate movement of the flow channels
such that the distribution of the treating chemistry is increased while minimizing
dye transfer due to frictional interactions between items.
[0072] Figures 6A-B are a schematic representation of the change in flow channels through
the load as the drum speed increases from below 1 G to above 1 G. Referring now to
Figure 6A, as the load is wetted with the dye fixative while the drum 60 is rotating
at speeds below 1 G, gravity is the primary force acting on the liquid distributing
through the laundry, so the flow channels may generally be considered to be primarily
vertical, as illustrated by arrows 91. As the spin speed is slowly increased, centrifugal
forces begin to play more of a role and the flow channels may begin to vary from vertical,
as illustrated in Figure 6B. As illustrated in Figure 6C, as the spin speed increases
to 1 G, the speed at which the centrifugal acceleration at the outermost extent of
the drum 60 is equal to the acceleration due to gravity, the centrifugal forces at
the periphery of the drum 60 are equal to gravity and the flow channels may vary from
the initial vertical channels at the center of the drum to nearly 45 degrees at the
periphery of the drum 60.
[0073] As the drum 60 is rotated above 1 G, the centrifugal force begins to exceed the force
due to gravity and the flow channels may begin to approach a more horizontal orientation.
In addition, at speeds above 1 G, the laundry begins to satellize. This movement of
the laundry load is small enough such that dye transfer due to frictional contact
is not significant, but still provides a sufficient degree of shifting of the load
to aid in dispersion of the dye fixative. Thus, by varying the spin speed from below
1 G to above 1 G while spraying the dye fixative onto the laundry, a multitude of
flow channels and load orientations may be produced which may facilitate distribution
of the dye fixative within a shortened amount of time.
[0074] Still referring to Figures 6A-B, during the application of the dye fixative, some
amount of liquid 93 may collect within the tub 54. As the rotation speed of the drum
60 is increased, the liquid 93 may travel up the sidewall of the tub 54 to such an
extent that the liquid 93 may come into contact with an outer edge of the drum 60
where the drum sidewall meets the drum bottom wall, as illustrated in Figures 6B and
C. The liquid 93 that comes into contact with the drum 60 may then be absorbed through
the drum perforations (not shown) by laundry inside the treating chamber 62 adjacent
the outer edge of the drum 60. This may facilitate distributing the dye fixative to
the laundry located near the outer edge of the drum 60.
[0075] In addition to rotating the drum 60 at increasing spin speeds during spraying of
the dye fixative, the rotation of the drum 60 may include periods where the speed
of the drum 60 is held constant while the dye fixative continues to be sprayed. At
specific speeds, centrifugal forces combined with a drum 60 which is configured to
restrict the flow of liquid out of the drum 60, results in some amount of liquid being
held near the outer edge of the drum 60 such that a paraboloid of sorts forms (not
shown). The shape of the paraboloid depends on the speed at which the drum 60 is rotating
and the configuration of the drum apertures which restrict the liquid flow. Forming
the paraboloid in this manner may allow portions of the load at the outer edges of
the drum 60 where the sidewall and bottom wall meet, which are not directly impacted
by dye fixative being sprayed into the treating chamber 62 by the sprayer 74, to be
wet with the dye fixative. While the wetting methods have been described in the context
of wetting the laundry load with a dye fixative, it will be understood that the methods
may also be used in a similar manner to wet the laundry with any other type of treating
chemistry or to wet the laundry with water.
[0076] The amount of dye fixative or any treating chemistry applied during the pre-wash
phase 14 may be automatically or manually determined based on the amount of laundry
and/or a volume of water that will be applied to the laundry during the cycle of operation.
When the pre-wash phase 14 supplies a treating chemistry, it may also be considered
a treating chemistry phase, and in the specific embodiment of a dye fixative, a dye
fixative phase. The amount of laundry may be determined automatically using one or
more sensors or according to a load detection method, as discussed above. Alternatively,
the user may indicate the amount of the laundry through the user interface by selecting
an amount of laundry (e.g. small, medium, large, extra-large, or by inputting a mass
or weight) or based on the cycle selection. The amount of treating chemistry supplied
to a mixing chamber or to the sump 58 may be based on the amount of water to be applied
to the laundry, which may be based on the amount of laundry and/or the selected cycle
of operation. Alternatively, the amount of treating chemistry may be defined by an
amount provided to the dispensing system by the user.
[0077] In one example, the amount of a dye fixative supplied is based on the load size and
is within a predetermined range that is dependent on the type of dye fixative being
used. For the exemplary dye fixative Sera Fast CTE, the predetermined range may be
determined to be between 5 grams per kilogram of laundry and 10 grams per kilogram
of laundry. For some dye fixatives, too much dye fixative may have undesired consequences
and therefore maintaining the amount of dye fixative below a certain amount based
on the amount of laundry may be beneficial. For example, if the concentration of dye
fixative is too high, the dye fixative may not entirely partition onto the laundry
fabric, but rather may preferentially remain in aqueous solution, which may draw dye
from the fabric into the aqueous solution.
[0078] Referring now to Figure 7, an additional or alternative method 150 for facilitating
distribution of a treating chemistry, such as a dye fixative, fabric softener, detergent,
fabric finish or stain repellant, for example, onto the laundry is illustrated. The
method 150 may be used with any method for distributing a treating chemistry, including
the methods described herein, such as the cycle 10 of Figure 1 or the method 120 of
Figure 5, for example. By way of non-limiting introduction, a fabric surface within
a bulk liquid may be considered to have a boundary layer of fluid flow on the fabric
surface. When a substance is added to the bulk liquid, initially the concentration
of the substance at the boundary layer for a homogenous liquid is the same as the
bulk concentration, c
b. The amount of substance and the time it takes for the substance to diffuse through
the boundary layer depends on c
b and the thickness of the boundary layer. A lower initial concentration and a thicker
boundary layer may result in a slower rate of diffusion to the fabric surface.
[0079] The method 150 begins with assuming that a user has loaded laundry items into the
treating chamber and initiated a cycle of operation. At 152 the thickness of the boundary
layer of the fabric may be increased. At 154 a liquid including a treating chemistry
may be supplied to the treating chamber for distribution onto the fabric. The supply
of the treating chemistry may occur simultaneously with the increase in the thickness
of the boundary layer or at some delayed time after the start of the increase in the
thickness of the boundary layer at 154. After a predetermined period of time, the
boundary layer may be decreased at 156 to facilitate diffusion of the treating chemistry
through the boundary layer for interaction with the surface of the fabric.
[0080] The thickness of the boundary layer may be increased at 152 by having a low velocity
of liquid flow through the fabric items, such as by having a slow drum rotation speed
which causes little to no relative movement of the fabric items. Exemplary drum speeds
are in the range of 20-120 rpm. An additional or alternative manner by which the thickness
of the boundary layer may be increased includes maintaining the temperature of the
liquid at a predetermined temperature to increase the viscosity of the liquid relative
to the viscosity of the liquid in the subsequent boundary layer thickness decreasing
phase 156. Additionally, or alternatively, less liquid may be applied to the load
to decrease normal forces and decrease the pressure. For example, in a typical cycle
for a 100% cotton load, the cycle may be configured to saturate the load to about
200% of the load weight. According to the method 150, the amount of liquid applied
may be such that the load is saturated to a less degree than the load would typically
be, such as just until saturation.
[0081] Decreasing the thickness of the boundary layer at 156 may be done at a predetermined
time after the start of the supply of the treating chemistry 154 to provide time for
the treating chemistry to distribute through the load, and may include rotating the
drum at higher spin speeds, such as speeds greater than 120 rpm or speeds above 1
G, than used during the increasing thickness phase 152 or agitating/tumbling the laundry.
In one example the drum may be rotated at speeds equal to or greater than 280 rpm.
Alternatively or additionally, the viscosity of the liquid may be increased by increasing
the temperature of the liquid and/or adding substances which may reduce viscosity
and/or increase lubrication, such as a polyox, for example. Another example includes
adding more liquid to the load to increase the pressure drop by increasing the normal
force. The normal force can be increased by having more water in the fabrics than
normal or, in the case of a horizontal axis washing machine, by increasing the drum
speed so that the release of the fabric as it is rotated by the drum is at a greater
height above the drum axis than is typically used.
[0082] In an exemplary embodiment in which a cationic dye fixative is applied to a cotton
fabric, the positively charged dye fixative may be electrostatically attracted to
the negatively charged cotton fabric such that the dye fixative may bond to the fabric
surface before dispersing over the fabric surface, leading to localized spots of high
concentrations of dye fixative. The thickness of the fabric surface boundary layer
may be increased prior to supplying the treating chemistry to slow the rate at which
the dye fixative reaches the cotton fabric and electrostatically bonds thereto, which
may provide more time for the dye fixative to spread out and cover a larger surface
area of the fabric surface. After a predetermined period of time, the boundary layer
thickness can be decreased or collapsed to facilitate the dye fixative reaching the
surface and electrostatically bonding to the cotton.
[0083] An alternative or additional method for facilitating distribution of the dye fixative
on the laundry includes increasing the hydrophobicity of the fabric surface. Introduction
of water to the fabric surface may interrupt the forces, such as Van der Waal's forces,
for example, between the fabric surface and loosely held dyes at the fabric surface.
The water may form hydrogen bonds with the fabric surface and/or dye and promote partitioning
of hydrophobic dyes away from the fabric surface to the air-water interface. Increasing
the hydrophobicity of the fabric surface may reduce this partitioning of the dye away
from the fabric surface in the presence of water. The hydrophobicity of the fabric
surface may be increased by applying an oil to the fabric surface, such as a natural
fatty acid-based oil, for example. The oil may be applied to the fabric surface through
spraying, misting or vapor deposition, and/or may be supplied as an emulsion. The
oil on the fabric surface may facilitate the interaction between the fabric and the
dye to retain the dye at the fabric surface, even as water or a water-based treating
chemistry, such as a dye fixative, for example, is supplied to the laundry. The oil
may then be removed, such as during a subsequent wash phase with a surfactant, for
example.
[0084] In the context of the wash cycle 10, the oil may be supplied to the laundry prior
to the pre-wash phase 14 to inhibit dye transfer that may occur as the dye fixative
solution is being supplied to the laundry. In one example, this may result in the
ability to apply a greater volume of the dye fixative solution to the laundry to facilitate
distribution of the dye fixative solution without promoting excessive dye transfer.
In another example, the application of the oil to the fabric surface may negate the
use of the pre-wetting phase 12.
[0085] Another method by which distribution of the dye fixative on the fabric surface may
be facilitated includes preparing a delayed or trigger-released dye fixative. The
dye fixative may be encapsulated inside a colloidosome microcapsule to prevent the
dye fixative from prematurely adhering to the fabric surface and collecting in localized
spots on the fabric surface. The encapsulated dye fixative may be formed by preparing
a water-in-oil-in-water (W/O/W) double emulsion in which the dye fixative is encapsulated
in an oil shell which is then dispersed in an aqueous phase.
[0086] The oil shell may be formed from any suitable oil, and in an exemplary embodiment,
is formed from a natural oil, such as sunflower oil, soybean oil or a vegetable oil,
for example. Formation of the encapsulated dye fixative double emulsion generally
includes mixing an oil phase and an aqueous phase in which the dye fixative is dispersed,
emulsifying the oil and aqueous phase, stabilizing the oil shell, and transferring
and re-dispersing the encapsulated dye fixative in an aqueous phase. The exact procedure
by which the double emulsion may be formed depends on the oil used in the oil phase,
the dye fixative, and the composition of the aqueous phase.
[0087] An exemplary double emulsion for encapsulating a dye fixative, such as a cationic
methylene guanidine based dye fixative (commercially available under the trade name
Retayne™), in a soybean oil shell is illustrative of the process and product envisioned.
It will be understood that the process may be used in a similar manner to encapsulate
other water-soluble dye fixatives in different oil shells and that additional or different
steps and material may be included to obtained the desired encapsulated dye fixative.
[0088] The emulsification process begins with dispersing the dye fixative in an aqueous
phase, which may include only water. An oil-in-water emulsion may be formed by mixing
a desired oil phase, soybean oil for example, with the aqueous phase in which the
dye fixative is already dispersed in the presence of an emulsifier. A non-limiting
example of a suitable emulsifier includes a nonionic surfactant, such as polyethylene
glycol sorbitan monostearate (commercially available as TWEEN® 60 from Sigma-Aldrich®).
An exemplary ratio for the oil and aqueous phases is 50%/50% soybean oil/aqueous phase.
The mixture may be stirred and optionally heated, e.g. 70 °C, to promote the emulsification
process. The oil-in-water mixture may then be introduced into an electrolyte solution
for further mixing and homogenization, using an ultra-sonicator, for example, to form
the desired emulsion. Non-limiting examples of emulsification machines which may be
used to form the oil-in-water emulsion include a stirring vessel, a colloid mill,
a toothed disc dispersing machine or a high-pressure homogenizer. The resultant oil
encapsulated dye fixative comprises a dye fixative dispersed in water encapsulated
within an oil shell which is stabilized by the nonionic surfactant.
[0089] The oil encapsulated dye fixative may then be transferred into an aqueous phase and
re-dispersed to form the double emulsion. The oil shell may be stabilized by the further
addition of a nonionic surfactant, such as polyethylene glycol sorbitan monostearate,
with additional sonication. The stability and size of the oil encapsulated dye fixative
droplet may be varied depending on the emulsification process machines and materials.
[0090] In another example, the colloidosome microcapsule may be formed by self-assembly
or directed assembly of responsive materials, such as pH responsive materials, using
co-polymer-stabilized water/organic solvent/water (W/O/W) double emulsions. A water-in-oil-in-water
(W/O/W) emulsion may be generated by self-assembling pH responsive materials at the
liquid-liquid interfaces, for example, and removing the middle phase through evaporation.
The outer shell may be hydrophobic and dissolve in water at a predetermined pH threshold.
The pH of the dye fixative solution applied to the laundry may be kept outside the
predetermined pH threshold until such time as it is desired to release the dye fixative
to facilitate distribution of the dye fixative across a larger area of the fabric
surface and decrease localized or spotty distribution of the dye fixative.
[0091] For example, if the outer shell dissolves at a pH >7, the treating liquid may be
kept at a pH <7, such as by adding citric acid, for example. Increasing the pH above
7 releases the dye fixative from the colloidosome microcapsule. The pH may be increased
above 7 at some predetermined delayed time following the beginning of the application
of the treating liquid with the encapsulated dye fixative. Delaying the release of
the dye fixative may facilitate more uniform application of the dye fixative through
the laundry load. Because the dye fixative is attracted to the fabric surface, the
dye fixative may have a tendency to concentrate at the first surface the dye fixative
comes into contact, limiting its distribution. Encapsulating the dye fixative in a
triggered-release microcapsule may allow for more time to distribute the dye fixative
throughout the load before the dye fixative becomes strongly associated with the fabric
surface. In another example, the oil shell may be broken or de-stabilized to release
the dye fixative within by application of mechanical energy, such as may occur when
laundry to which the encapsulated dye fixative has been applied is agitated, or based
on changes in pressure or temperature. In yet another example, an additional material
may be supplied to the laundry to de-stabilize the oil shell, triggering release of
the dye fixative from within the oil shell.
[0092] Any of the water-soluble dye fixatives described herein may be encapsulated using
the double emulsion process, non-limiting examples of which include cationic polymers
containing functional groups selected from the group consisting of primary, secondary,
and tertiary amines and their salts, polyacrylamide or polyethyleneimine based polymers,
polymers containing a reactive vinyl, hydroxyl or epoxy functional group, poly diallyl
dimethyl ammonium chloride (DADMAAC), poly(acrylamide-co-diallyldimethyl ammonium
chloride), cetyl trimethyl ammonium bromide (CTAB), or cetyl pyridinium bromide (CPB).
[0093] The encapsulated dye fixative may be formed in a dispersing machine associated with
the clothes washer on demand or provided as a prepared chemistry in a treating packet,
for example. In one example, a mixture of the water-in-oil emulsion may be stored
in a suitable container and provided to the consumer for addition to the clothes washer.
The clothes washer may include a dispersing machine or mixing chamber capable of re-dispersing
the water-in-oil emulsion in an aqueous phase to form the double emulsion, which may
then be supplied to the laundry by the clothes washer during the cycle of operation.
In another example, the water-in-oil emulsion may be mixed within a sump of the clothes
washer with a suitable aqueous phase to form the double emulsion.
[0094] Referring again to the wash cycle 10 of Figure 1, the optional intermediate phase
24 may be implemented following the pre-wash phase 14 and prior to the main wash phase
16 to prepare the laundry for treatment during the main wash phase 16. Figure 8 illustrates
exemplary methods which may be used to implement the intermediate wash phase 24. Method
200 may include a drain phase 202 in which treating liquid collected in the sump 58
is drained from the treating chamber 62 and an optional extraction phase 204 in which
the laundry is rotated to facilitate the extraction of liquid from the laundry, which
may subsequently be drained from the sump 58.
[0095] Method 206 may include the optional extraction phase 204 and drain phase 202 of method
200 and further include supplying the drained treating liquid to a filter to filter
dye fixative from the treating liquid at 208. The filtered treating liquid may then
be re-applied to the laundry in the treating chamber 62 at 210. The applied filtered
treating liquid may then be drained at 202 following the optional extraction phase
at 204. The drain 202, optional extraction 204, filtering at 208 and application of
filtered liquid at 210 may be repeated a predetermined number of times or based on
output from a sensor system indicative of an amount of dye fixative in the treating
liquid drained at 202. The sensor system may include any suitable system for determining
an amount of dye fixative in the treating liquid, non-limiting examples of which include
optical sensor systems which may be used to perform UV/Vis absorbance/fluorescence
spectroscopy or a conductivity sensor. For example, a UV/Vis absorbance/fluorescence
system may provide an output representative of a sensed spectral absorbance and/or
fluorescence of the treating liquid. It will also be understood that, as used herein,
when referring to absorbance, transmittance, which is related to absorbance, may be
used as an alternative to absorbance or in order to determine the absorbance.
[0096] The method 206 may be repeated multiple times until the output indicates that the
amount of dye fixative in the treating liquid satisfies a predetermined threshold.
This may include comparing the output to a predetermined reference value that may
be a range of reference values, an upper threshold or a lower threshold. The term
"satisfies" the threshold is used herein to mean that the variation satisfies the
predetermined threshold, such as being equal to, less than, or greater than the threshold
value. It will be understood that such a determination may easily be altered to be
satisfied by a positive/negative comparison or a true/false comparison. For example,
a less than threshold value can easily be satisfied by applying a greater than test
when the data is numerically inverted. In another example, the method 206 may be repeated
multiple times based on the dye fixative, load amount and/or load type.
[0097] Alternatively, the optional intermediate phase 24 may include a method 212 which
includes the optional extraction phase 204 and drain phase 202 of method 200 and further
includes applying rinse water 214 from the household water supply to the laundry and
repeating the optional extraction at 204 and draining at 202. Similar to the method
206, the drain 202, optional extraction 204, and application of rinse water at 214
may be repeated a predetermined number of times or based on output from a sensor system
indicative of an amount of dye fixative in the liquid drained at 202, as described
above. For example, the method 212 may be repeated multiple times until the output
indicates that the amount of dye fixative in the treating liquid satisfies a predetermined
threshold. In another example, the method 212 may be repeated multiple times based
on the dye fixative, load amount and/or load type.
[0098] While the intermediate phase 24 is illustrated in Figure 1 between the pre-wash phase
14 and the main wash phase 16, it is within the scope of the invention for the intermediate
phase 24 to alternatively or additionally be implemented between one or more of the
phases 12, 14, 16, 18 and/or 20 of the cycle 10.
[0099] The main wash phase 16 may include the addition of a laundry detergent composition
comprising one or more surfactants, detergents, soaps and optional additional adjuncts
that are known for use in laundry detergent compositions, non-limiting examples of
which include pH buffers, builders, viscosity modifying agents, colorants, fragrances,
etc. In addition to washing the laundry with a laundry detergent composition, the
laundry may also be treated with a dye absorber in the main wash phase 18. The dye
absorber may be part of the laundry detergent composition or a separate agent that
may be supplied to the laundry in the treating chamber before the laundry detergent
composition is supplied or simultaneously with the laundry detergent composition.
As will be described in more detail below, the laundry detergent composition may be
formulated so as to not include anionic surfactants, or if anionic surfactants are
included, only sulfate-based anionic surfactants. In such a case, surfactancy may
be provided by nonionic surfactants or mixtures of cationic and nonionic surfactants.
Anionic surfactants may promote dye removal and may also interact undesirably with
dye fixative that may have been carried over from the pre-wash phase 14.
[0100] For example, the dye absorber may be provided to the tub 54 and diluted with water
from the household water supply 72. The dye absorber and water in the tub 54 may be
recirculated through the recirculation conduit 80 and back into the tub 54 without
application to the laundry load 86 to mix the dye absorber and water prior to application
the laundry load 86. Alternatively, the dye absorber may be mixed with water in a
mixing chamber prior to spraying the dye absorber solution into the treating chamber
62. The dye absorber mixed with water may be applied to the laundry before the addition
of a laundry detergent composition. Alternatively, following mixing of the dye absorber
and water, the detergent composition may be added to the dye absorber solution, optionally
mixed by circulation through the recirculation conduit 80, and then applied to the
laundry load 86.
[0101] The rinse phase 18 may include supplying a rinse liquid to the treating chamber comprising
a dye absorber that may be the same or different than the dye absorber supplied in
the main wash phase 16. The rinse liquid may optionally include additional laundry
adjuncts such as fabric softener, for example. The rinse phase 18 may include supplying
the tub 54 one or more times with rinse liquid comprising a dye absorber in at least
one of the rinses. Each time the tub 54 is filled with a rinse liquid or rinse water
and subsequently drained, this may be considered a rinse stage. Although, depending
on the volume of rinse liquid, it is possible to have multiple rinse phases without
an intervening draining. Each rinse stage may optionally include agitating the laundry
within the treating chamber62 by activating the clothes mover 64 and/or rotating the
drum 60, if dye absorber has been added in the main wash phase 16 and/or the rinse
phase 18. Agitating the laundry may facilitate removal of undesired dyes, such as
the removal of dyes that have transferred to white or light colored fabric in the
load, for interaction and subsequent removal with the dye absorbers.
[0102] When a dye absorber is supplied in the rinse phase 18, the rinse phase 18 may be
considered a dye removal or dye scrubber phase which can be implemented as part of
a rinse phase of the selected cycle of operation or independent of a rinse phase of
the selected cycle of operation. In one example, a dye removal/dye scrubber rinse
phase 18 may be implemented automatically, based on sensor data, or manually, based
on a selection by the user through a user interface of the appliance.
[0103] Figure 9 illustrates an exemplary dye absorber rinse cycle 300 that may be used in
the rinse phase 18 of the wash cycle 10, as part of another cycle of operation or
as a separate cycle. The rinse cycle 300 may include a first rinse stage 302 followed
by a second rinse stage 304. The first and second rinse stages 302 and 304 may include
supplying a rinse liquid and/or rinse water to the treating chamber 62. The rinse
liquid in the first and second rinse stages may include one or more treating chemistries,
non-limiting examples of which include fabric softener, stain repellant, fragrance,
wrinkle inhibitors, etc... The first and second rinse liquid may also optionally include
a dye absorber. During the final rinse stage, which in the exemplary rinse cycle 300
is the third rinse stage 306, the laundry may be rinsed in rinse liquid containing
a dye absorber. Applicants have found that if dye absorber is not included in the
final rinse stage 306, the likelihood of dye transfer occurring in the final rinse
stage increases. While the rinse cycle 300 is illustrated as having three rinse stages,
it will be understood that the rinse cycle 300 may have greater or fewer stages prior
to the final rinse.
[0104] While not meant to be limited by theory, it is believed that during the first and
second rinse stages 302 and 304 following a main wash phase 16 in which dye absorbers
were supplied to the laundry, there may be enough residual dye absorbers carried by
the laundry to inhibit dye transfer during the first and second rinse stages 302 and
304. However, each rinse stage rinses away at least a portion of the residual dye
absorber. Thus, at the third rinse stage 306 the amount of residual dye absorber may
be too low to inhibit dye transfer and a dye transfer event may occur. Supplying a
rinse liquid in the third rinse stage 306 that includes dye absorber may inhibit dye
transfer in the final rinse stage. In addition, even if dye transfer does occur in
the first and second rinse phases without any dye absorber present, the dye transfer
may still be removed in the third phase by supplying absorbers. However, if no dye
absorber is present in the third/final rinse, there is no subsequent phase with absorber
to remove the dye transfer. While additional dye absorber may be added in the rinse
stages preceding the final rinse stage 306, this may not be necessary, for the reasons
just discussed. In addition, too much dye absorber may be undesirable and may further
increase costs to the consumer in the amount of chemistry they have to purchase.
[0105] Following the third rinse stage 306, an optional quick rinse 308 may be implemented
with rinse liquid that does not include dye absorber to remove at least a portion
of the dye absorber associated with the laundry. A quick rinse 308 may differ from
the rinse stages 302, 304 and 306 in either or both a smaller amount of liquid supplied
to the laundry and/or a shorter length of time the laundry is in contact with the
liquid to minimize dye transfer. In addition, the quick rinse 308 may include minimal
agitation of the laundry to minimize the likelihood of dye transfer by contact. The
quick rinse 308 may be used to supply rinse liquid to remove at least a portion of
the dye absorber associated with the laundry.
[0106] The combination of dye fixatives and dye absorbers in the same wash cycle may be
complementary in that when a cationic dye fixative interacts with a fabric surface,
the cationic dye fixative may provide a positive charge to the fabric surface which
may attract soils, which are generally negatively charged. This attraction of loose
soil may increase the appearance of fabric dinginess. The dye absorber in solution
during the main wash phase 16 and rinse phase 18 may act as a sacrificial polymer
that may preferentially attract the loose soils relative to the dye fixative on the
fabric surface.
[0107] Stages 302 through 308 of the method 300 may be used with the wash cycle 10 or, alternatively,
the method 300 may be used as a separate cycle. When part of a separate cycle, the
method 300 may include a main wash phase 310. The main wash phase 310 may be similar
to the main wash phase 16 of the cycle 10 in that the main wash phase 310 may include
supplying dye absorbers to the laundry, however, the alternative cycle would not include
the application of a dye fixative.
[0108] Figure 10 illustrates a clothes washer 450 that is similar to the clothes washer
50 except for the drum 460 is oriented generally horizontally rather than vertically.
The clothes washer 450 is often referred to as a "front loader" or "horizontal axis"
machine, even though the axis of rotation is not always perfectly horizontal. The
clothes washer 50 is often referred to as a "top loader" or a "vertical axis" machine.
Horizontal and vertical axis machines primarily differ in the manner in which they
impart mechanical energy to the laundry. Horizontal axis machines impart mechanical
energy by lifting and dropping, often referred to as tumbling, the laundry within
the drum 460, whereas vertical axis machines have a clothes mover, such as an agitator,
nutator, impeller, etc., within the drum which rotates to apply mechanical energy
to the laundry. As many elements of the horizontal axis and vertical axis machines
are similar, elements of the clothes washer 450 similar to those of clothes washer
50 have been labeled with the prefix 400.
[0109] The clothes washer 450 may also be used to implement the dye transfer prevention
wash cycle 10 and any of the other methods described herein. However, because the
orientation of the drum 460 and thus the orientation of the laundry within the treating
chamber 462 is different in the horizontal axis clothes washer 450 than the vertical
axis clothes washer 50, the manner in which liquid is supplied to the laundry may
differ. It will be understood that all of the methods and compositions described herein
may be used with both a horizontal axis clothes washer and a vertical axis clothes
washer unless explicitly stated otherwise, even if the method or composition is described
in the context of only one of the types of clothes washers.
[0110] The cycle 10 for a horizontal axis clothes washer may include the laundry load detection
phase 22, which may be the same as that described above with respect to the vertical
axis clothes washer 50 and the method 100, for example, or differ in the use of other
inertia-based methods that are configured for use with horizontal axis clothes washers.
However, in a horizontal axis clothes washer, the pre-wetting phase 12 may be skipped
and the laundry may be initially wet in the pre-wash phase 14.
[0111] Application of a dye fixative in the pre-wash phase 14 in the context of the horizontal
axis clothes washer 450 may include a combination of spraying a recirculating dye
fixative solution into the treating chamber 462 from the tub 454 with the recirculation
sprayer 474 and rotating the laundry through the dye fixative solution in the tub
454. For example, a dye fixative may be dispensed from a dispenser 490 and mixed with
water supplied into the tub 454 from the water supply 472. The dye fixative and water
supplied to the tub 454 may be mixed by recirculation through the recirculation conduit
480 without application to the laundry to form a dye fixative solution.
[0112] The drum 460 may be rotated such that the laundry rolls, flips, or tumbles through
the dye fixative solution collected in the sump area 458 of the tub 454 with optional
dwell times to facilitate wicking of the dye fixative solution. The dye fixative solution
may also be continuously or intermittently sprayed into the treating chamber462 through
the recirculation sprayer 474, such as according to the method 120 of Figure 5, for
example. In this manner, both the exposed first strike surface 488 of the laundry
facing the treating chamber 462 and the opposite side of the laundry facing the sidewall
of the drum 460 are wet with the dye fixative solution. The drum 460 may further be
rotated at increasing speeds up to a satellizing speed such that the laundry 486 redistributes
within the drum 460 to expose additional laundry surfaces for wetting with the dye
fixative solution. For some small loads it may not be necessary to recirculate solution
through the sprayer 474 to adequately wet the load with the dye fixative solution.
[0113] Referring now to Figure 11, a dispensing control method 500 for dispensing dye fixatives
and dye absorbers in a clothes washer is illustrated. The dispensing control method
500 may be used with the wash cycle 10 of Figure 1 to dispense a dye fixative in the
pre-wash phase 14 or a dye absorber in the main wash phase 16 or rinse phase 18. The
dispensing control method 500 may also be used with any other cycle of operation to
dispense a dye fixative, dye absorber, or other treating chemistry.
[0114] The method 500 may begin with supplying a first portion of the treating chemistry,
such as a dye fixative or dye absorber, during a first stage of the cycle of operation
or a first stage of a phase of the cycle of operation at 502. Supplying a portion
of a treating chemistry may refer to dispensing a portion of an undiluted treating
chemistry into a liquid (e.g. water, a wash liquid, or a rinse liquid) for dilution
and then supplying the diluted treating chemistry to the treating chamber. Alternatively,
supplying a portion of a treating chemistry may refer to supplying a portion of a
treating chemistry solution in which a treating chemistry has already been diluted
with a liquid. The first stage may refer to a beginning of the cycle or phase or a
predetermined time period after the beginning.
[0115] At 504 a second portion of the treating chemistry is supplied during a second stage
of the phase. An n
th portion of the treating chemistry may be supplied at successively later stages of
the phase at 506 until a final portion of the chemistry is supplied. The cycle or
phase may be completed at 508 without further addition of the treating chemistry.
The amount of treating chemistry supplied during each stage of the cycle or phase
and the timing within the phase during which the treating chemistry is supplied may
be determined experimentally or empirically so as to maintain a concentration of the
treating chemistry in the treating chamber at a predetermined concentration or within
a predetermined range based on the treating chemistry.
[0116] A control system, such as an open loop control system, may be used to control the
amount and timing of supplying at each stage based on the treating chemistry being
supplied according to a control algorithm associated with the control system. The
treating chemistry may be supplied at each stage as either a single shot at a beginning
of each stage or supplied intermittently or continuously throughout the course of
each stage. When the treating chemistry is supplied throughout the stage, the amount
of chemistry supplied may be controlled by controlling a rate at which the chemistry
is supplied or a duration of on/off times of a pump for supplying the chemistry. This
may include controlling the rate or on/off periods of a dispenser metering pump or
a pump used for recirculating liquid from the sump into the treating chamber. The
type of treating chemistry may be determined automatically based on sensor information
or the selected cycle information or may be determined manually based on user input.
[0117] For example, the first portion of the treating chemistry supplied at the beginning
of the phase may be determined to be an amount which brings the concentration of the
treating chemistry in the treating chamber to within a predetermined preferred or
effective range, above a predetermined lower threshold and/or below a predetermined
upper threshold. The amount of the second portion of treating chemistry and the timing
of the second stage may be determined so as to maintain the concentration of the treating
chemistry in the treating chamber within the predetermined range such that the concentration
of the treating chemistry remains relatively constant from the first stage to the
second stage. The amount of each n
th portion and the timing of each n
th stage for dispensing may be determined so as to maintain the concentration of the
treating chemistry within the predetermined range throughout each stage. The amount
and timing of the last portion of treating chemistry supplied during the last stage
may be determined so as to maintain the concentration of the treating chemistry within
the predetermined range until the end of the cycle or phase.
[0118] An exemplary algorithm for controlling dispensing according to the method 500 may
include supplying 50% of a total dose of a treating chemistry at the beginning of
the cycle or phase, supplying the next 35% of the total dose over the course of the
first half of the cycle or phase, and the remaining 15% of the total dose during the
third quarter of the cycle or phase with no additional treating chemistry supplied
during the final quarter of the cycle. In this manner, as the treating chemistry is
depleted or "used up" as the cycle or phase progresses, the remainder of the treating
chemistry dose may be supplied to replenish the depleted treating chemistry such that
the concentration of the treating chemistry remains relatively constant as the cycle
or phase progresses.
[0119] Alternatively, rather than an open loop control system in which the dispensing of
the treating chemistry is not controlled based on feedback to the controller, the
method 500 may be implemented using a closed loop system based on sensor information.
A sensor system may be configured to provide sensor data indicative of a concentration
of the treating chemistry which may provide feedback to the closed loop system which
includes a control algorithm to vary the amount and/or timing of the treating chemistry
supplied. For example, the closed loop system may continuously vary a rate at which
treating chemistry is supplied during each stage based on the feedback from the sensor
system.
[0120] The sensor system may include any suitable system for determining a characteristic
of the liquid indicative of the concentration of a dye(s) in the liquid. The sensor
system may determine the concentration of the dye in liquid that is being recirculated
within the clothes washer, collected in the sump of the clothes washer or drained
from the clothes washer. Non-limiting examples of suitable sensor systems include
ultraviolet or visible light absorbance/transmittance or fluorescence systems, a conductivity
sensor, and/or a turbidity sensor.
[0121] For some chemistries, such as dye fixatives and dye absorbers, it may be desirable
to maintain the concentration of the chemistry within a predetermined range to avoid
failure modes and unnecessary costs to the consumer. The concentration of available
dye fixative or dye absorber in solution, i.e. fixative or absorber that is available
for associating with dye molecules, may decrease over time through the course of the
cycle or phase as the fixative or absorber complexes with dye in solution or on fabric
or otherwise becomes unavailable, such as by interaction with surfaces of the clothes
washer or other contaminants in solution. As the amount of available dye fixative
or dye absorber is depleted, the concentration of the dye fixative or dye absorber
may decrease to a concentration outside of a predetermined range or below a predetermined
threshold, making it difficult to maintain a constant concentration throughout the
cycle or phase or to keep the concentration within a predetermined range or above
a predetermined threshold.
[0122] If there is not enough available dye fixative or dye absorber in solution, the fixative/absorber
may not be able to adequately prevent dye transfer. For example, for dye absorbers,
sufficient available dye absorber in solution may be needed to ensure that sufficient
absorber is present to capture and suspend any fugitive dyes in solution before the
dyes can redeposit on another garment in the laundry. If the concentration of dye
fixative is too low, there may not be sufficient dye fixative present to prevent the
liquid in the treating chamber from lifting the dye from the fabric.
[0123] One way to address the depletion of available dye fixative/dye absorber through the
course of the phase or cycle may be to add a high concentration of dye fixative/dye
absorber, e.g. a concentration higher than the desired predetermined range or threshold.
However, if the concentration is too high, the possibility of fixatives/absorbers
depositing on components of the clothes washer and leading to undesired build-up may
increase. In addition, for some fixatives, increasing the concentration above a certain
threshold may decrease the efficacy of the dye fixatives and even exacerbate dye transfer.
Some dye absorbers may form undesirable suds if the concentration becomes too high.
Furthermore, even when the concentration of the dye fixative or dye absorber is increased
at the beginning of the cycle such that the identified problems above are avoided,
the concentration may still not be enough to maintain the concentration within a desired
range through the course of the cycle or phase.
[0124] For example, Figure 12 illustrates a graph 520 representing the change of a concentration
of a dye fixative, such as a cationic methylene guanidine based dye fixative commercially
available under the trade name Retayne™ (available from G&K Craft Industries), for
example, during mixing of the dye fixative with treating liquid prior to the start
of recirculation at 522, at the start of recirculation at 524 and at subsequent 30
second intervals during recirculation at 526. Figure 12 is used for illustrative purposes
only for the purpose of describing an embodiment of the invention and is not meant
to limit the invention in any manner. Consider, for example, the case described above
in which the dye fixative is supplied to the laundry in a concentration of about twice
the desired concentration. For example, when the desired predetermined concentration
range for the dye fixative for the cycle is 2-2.5 g/L, the dye fixative may be added
at the beginning of the cycle or phase, prior to the start of circulation, at a concentration
of approximately twice the desired concentration. As may be seen in Figure 12, at
the start of recirculation of the treating liquid at 524, the concentration of the
dye fixative has already decreased from the initial concentration of almost 4.5 g/L
to about 2 g/L. As the cycle or phase continues, the concentration of the dye fixative
decreases further to about 1 g/L, which is below the desired predetermined range.
Thus, simply overcharging the dye fixative at the start of a cycle or phase may not
be suitable for maintaining the concentration of the dye fixative within the predetermined
range throughout the course of the cycle or phase.
[0125] While the open and closed loop control systems of the method 500 have been described
in the context of dye fixatives and dye absorbers, the method 500 may be useful with
other treating chemistries as well, such as detergents, surfactants or bleaches, for
example. For example, in a cold water sanitization cycle, the concentration of chlorine
may be kept relatively constant at a low level throughout the course of the cycle
or phase that is sufficient to sanitize the laundry while not affecting the colorfastness
of the laundry. However, if the concentration varies outside a predetermined range,
either sanitization may not be achieved or colorfastness of the laundry may be effected.
[0126] Referring now to Figure 13, a method 550 for determining an amount of dye absorber
to add during a cycle of operation is illustrated. The method 550 may be used to control
the supply of dye absorber to the laundry as needed so as to provide sufficient dye
absorber in solution to inhibit dye transfer while minimizing excess dye absorber.
The method 550 may be used with the closed loop system of method 500 or any other
method for dispensing a dye absorber. While the method 550 is described in the context
of dye absorbers, it will be understood that the method 550 may be used in a similar
manner with dye fixatives or other chemistry.
[0127] The method 550 begins with the assumption that a user has loaded the clothes washer
with one or more laundry items and selected a cycle of operation which uses dye absorbers.
At 552 an initial dose of dye absorber may be supplied to the treating chamber for
treating the laundry. The amount of initial dye absorber supplied may be determined
automatically based on sensor data, characteristics of the load (e.g. load amount),
or the selected cycle, for example, or manually based on information provided by the
user.
[0128] At 554 an absorbance and/or fluorescence (Abs/F) characteristic of the dye absorber,
which will be described in further detail below, may be determined. The Abs/F characteristic
may be of the dye absorber or of a composition which includes a dye absorber. The
Abs/F characteristic of the dye absorber may be determined based on information stored
in a memory accessible by a controller of the clothes washer. The information may
be in the form of a look-up table of absorbance or fluorescence spectra or data for
different dye absorbers. The identity of the dye absorber may be determined automatically
based on sensor data or manually based on user input and used to find the absorbance
or fluorescence spectra or data for the dye absorber in the look-up table. Alternatively,
the absorbance or fluorescence spectra for the dye absorber may be determined by the
clothes washer prior to application of the dye absorber to the laundry items. In one
example, the identity of the dye absorber may be determined using one or more sensors
in the dispenser to determine a characteristic of the dye absorber and a look-up table
stored in the controller may be used to determine the identity and/or spectra for
the identified dye absorber. In yet another example, the identity of the dye absorber
and/or the Abs/F characteristic may be determined based on information carried by
a container storing the dye absorber that may be communicated wirelessly with the
clothes washer controller (e.g. through an RFID system) or through a hard-wire connection
or which may be read by an appropriate sensor provided on the clothes washer (e.g.
a bar code/bar code reader system).
[0129] At 556 an Abs/F characteristic of the treating liquid after the dye absorber has
been supplied to the laundry in the treating chamber may be determined. The Abs/F
characteristic may be based on the absorbance or fluorescence of a dye absorber-dye
complex in solution or suspended within the liquid mixture, which may be representative
of the dye absorber level in the liquid mixture. The Abs/F characteristic may be determined
based on output provided by an optical sensor representative of a sensed spectral
absorbance and/or fluorescence of the treating liquid. It will also be understood
that when referring to absorbance herein, transmittance, which is related to absorbance,
may be used as an alternative to absorbance or in order to determine the absorbance.
For some dyes and dye absorbers, the dye absorber-dye complex UV and/or visible light
absorbance or fluorescence spectrum may be measurably different than the absorbance
or fluorescence spectrum for the individual dye and dye absorber components of the
complex. The Abs/F characteristic may be based on the absorbance/fluorescence of the
treating liquid at a single wavelength or over a range of wavelengths.
[0130] Figure 14 illustrates an exemplary absorbance spectrum 570 for a cationic polyamine
dye absorber in the presence and absence of a dye. As may be seen by dye absorber
spectrum 572, the dye absorber in the absence of dye has a strong absorbance in the
ultraviolet region. As may be seen by spectra 574 and 576, in the presence of increasing
concentration of dye, 10 mg/L and 20 mg/L, respectively, the absorbance spectrum shifts
compared to the absorbance spectrum 572 of the polyamine dye absorber alone. This
shift in absorbance in the presence of dye may be used as an indication of the presence
of a dye absorber-dye complex, which may be used to determine if enough dye absorber
is present in the treating liquid to complex with dye in solution.
[0131] Referring back to Figure 13, at 558 it may be determined if the Abs/F characteristic
of the treating liquid satisfies a predetermined threshold at one or more wavelengths.
This may include comparing the Abs/F characteristic to a predetermined reference value
that may be a range of reference values, an upper threshold or a lower threshold.
The reference value may be based on the known characteristics of the dye absorber.
In the embodiment of Figure 13, the threshold is a lower threshold. If the Abs/F characteristic
satisfies the lower threshold it may be determined that there is not sufficient uncomplexed
dye absorber in solution and one of two options 562 or 564 may occur. If the Abs/F
characteristic does not satisfy the lower threshold, it may be determined at 560 that
there is uncomplexed dye absorber in solution and additional dye absorber is not needed.
The term "satisfies" the threshold is used herein to mean that the variation satisfies
the predetermined threshold, such as being equal to, less than, or greater than the
threshold value. It will be understood that such a determination may easily be altered
to be satisfied by a positive/negative comparison or a true/false comparison. For
example, a less than threshold value can easily be satisfied by applying a greater
than test when the data is numerically inverted.
[0132] In a first option 562, an additional dose of dye absorber may be automatically supplied
to the laundry. The amount of the additional dose of dye absorber may be a predetermined
amount of dye absorber based on the Abs/F characteristic of the treating liquid determined
at 558 or independent of the Abs/F characteristic. The Abs/F characteristic of the
treating liquid may then be determined again at 556 and a determination of whether
the Abs/F characteristic of the treating liquid is below the predetermined threshold
is made at 558. The elements 556, 558 and 562 of method 550 may be repeated a predetermined
number of times or until the Abs/F characteristic is below the threshold.
[0133] Alternatively, or additionally, a second option 564 includes communicating to the
user that the amount of dye absorber was low or may not have been sufficient for the
load and providing the user with additional instructions. In one example, the user
may be prompted to add more dye absorber to the treating chamber and restart the cycle.
This may be useful in clothes washers with single dose dispensers in which the entire
dose of dye absorber provided in the dispenser is supplied to the treating chamber.
In another example, the user feedback could include warning the user to inspect the
load at the end of the cycle and optionally warning the user to not dry the laundry
under high heat. In another example, the feedback may include communicating information
to the clothes dryer to dry at a low temperature or to block a high temperature selection,
in a manner similar to that described below in method 1500 of Figure 26.
[0134] One example of a dye fixative composition according to an embodiment of the invention,
which may be suitable for use according to any of the methods described herein, includes
three cationic dye fixatives providing the composition with a tri-modal molecular
weight distribution, i.e. the composition contains three different discrete populations,
each within a predetermined range of weight average molecular weight
Mw. The combination of cationic fixatives having three different
Mw may be selected to inhibit dye bleeding of different dye types within a mixed load
of laundry or within a laundry item having multiple dye types. As discussed above,
the various dye types interact with the fabric differently and thus it is challenging
to find a single dye fixative that can address dye bleeding for all of the different
dye and fabric types.
[0135] For example, acid dyes are typically smaller than direct dyes and thus have a higher
diffusivity and smaller conformation. A suitable dye fixative for acid dyes may be
a dye fixative that is capable of forming a direct electrostatic bond with an individual
acid dye molecule and neutralize the charge. In addition, because acid and reactive
dyes are typically small molecules, generally in the range of 10 kDa, a dye fixative
for acid and reactive dyes may have to have high diffusivity to reach the fabric surface
before the acid/reactive dyes release from the fabric surface.
[0136] Direct dyes in contrast are larger molecules with anionic sites that remain on fabrics
because of favorable partitioning with the fabric as compared to the wash liquid.
A suitable dye fixative for direct dyes may be a large cationic molecule that can
bind to negatively charged fabric surfaces, such as cotton/cellulose, and form a polymeric
film on the fiber surface to prevent the release of direct dyes from the surface.
Because direct dyes are typically large molecules, small fixative molecules are not
always effective at inhibiting release of direct dyes from fabric surface.
[0137] According to one embodiment, the dye fixative composition may be designed so as to
inhibit dye bleeding of both direct and acid dyes. The first dye fixative may be a
large polymer having cationic functional groups capable of inhibiting dye bleeding
of direct dyes having an Mw greater than 200 kDa and a zeta potential greater than
20 mV. Non-limiting examples of polymers suitable for use as the first dye fixative
include cationic polymers containing functional groups selected from the group consisting
of primary, secondary, and tertiary amines and their salts, quaternary ammonium and
phosphonium salts, such as poly diallyl dimethyl ammonium chloride (DADMAAC) and poly(acrylamide-co-diallyldimethyl
ammonium chloride), polyacrylamide, and polyethyleneimine. In one example, the first
dye fixative may include a reactive functional group, such as a vinyl group, a reactive
hydroxyl group or an epoxy, for example, which may form a covalent bond with the fabric.
[0138] The second and third dye fixatives may be selected so as to inhibit dye bleeding
of reactive/acid dyes. The second dye fixative may be selected from polymers having
cationic functional groups having an Mw less 10 kDa but greater than 1 kDa and a zeta
potential of greater than 20 mV. Non-limiting examples of polymers suitable for use
as the second dye fixative include cationic polymers containing functional groups
selected from the group consisting of primary, secondary, and tertiary amines and
their salts, and quaternary ammonium and phosphonium salts.
[0139] The third dye fixative may be selected from surfactants, polymers and/or monomers
having an Mw less than 1 kDa, a zeta potential greater than 20 mV and a diffusivity
greater than 5x10
-6 cm
2/s. Non-limiting examples of substances suitable for the third dye fixative include
cetyl trimethyl ammonium bromide (CTAB), cetyl pyridinium bromide (CPB); diallyl dimethyl
ammonium chloride (DADMAAC). In one example, the dye cationic fixative includes at
least one polymer and/or monomer having a cationic functional group in combination
with a cationic surfactant.
[0140] The combination of different
Mw dye fixatives are selected so as to address dye bleeding from multiple different
types of dyes. Contrary to an industrial setting in which the fabrics and dye types
are uniform and/or at least well known to the user, in a residential setting different
fabrics and dye types may be mixed into a single load and therefore a dye fixative
composition that may address dye bleeding from different dye types may be beneficial
to the user in a residential setting. In addition, the smaller, high diffusivity cationic
molecules of the second and third dye fixative may partition to the fabrics first
compared to the larger polymer of the first dye fixative. The initial layer of smaller
cationic molecules on the fabric surface, such as a cellulose fabric surface, may
diffuse the negative surface charge of the cellulose, providing improved transportation
of the larger cationic molecules on the cellulose and hence improved distribution.
[0141] The dye fixative composition may also include an anionic fixative that has a very
low diffusivity and partitioning coefficient onto the laundry fabric so that the anionic
fixative partitions onto the fabrics last, after the first, second and third dye fixatives.
The anionic fixative may inhibit dye bleeding for acid dyes by fixing on a positively
charged nylon surface and forming a polymeric film on the surface. In addition, the
anionic fixative may interact with the cationic dye fixative which has already deposited
onto a fabric surface, such as a cotton surface, and decrease or neutralize the positive
charge imparted to the surface by the dye fixative. This may decrease the attraction
of negatively charged soils to the fabric surface. Alternatively, the rate at which
the anionic fixative deposits on the fabrics surface relative to the cationic dye
fixative may be slowed by selecting an anionic fixative that has a larger molecular
weight than the cationic dye fixative. Non-limiting examples of anionic fixatives
include polymers with the following functional groups - sulfonate, carboxylate, acrylic
acid, some examples of which include poly(acrylic acid), poly(methaacrylic acid),
poly(styrene sulfonate), poly(acrylamide-co-acrylic acid), poly(vinylsulfonic acid).
In an exemplary embodiment, the anionic fixative has an
Mw of 200 kDa or greater.
[0142] The first and second dye fixatives may comprise a polymer having cationic functional
groups, as described above. Alternatively, either or both the first and second dye
fixatives may be a zwitterionic molecule that includes both cationic and anionic functional
groups that become charged depending on cycle conditions. Non-limiting examples of
cationic functional groups include primary, secondary, and tertiary amines. Non-limiting
examples of anionic functional groups include sulfonates and carboxylates. The zwitterionic
molecule may be selected to provide the desired cationic or anionic charge at a predetermined
time or stage during a cycle of operation. In one example, the zwitterionic molecule
may include a cationic functional group that is charged at least between pH 6-8.
[0143] In another example, either or both the first and second dye fixatives may include
a dye-reactive functional group covalently bonded to the dye fixative to destroy or
otherwise disable the ability of a dye to color a fabric. The dye-reactive functional
group may include a reactive group, such as an oxidizing agent (e.g. sodium hypochlorite)
or a reducing agent (e.g. sodium thiosulfate). In another example, the dye-reactive
functional group may include catalyst materials that generate oxygen radicals, which
may be short lived. Non-limiting examples of suitable oxygen radical generating functional
groups include metal silicates, polyoxometalates and/or other metal complexes. In
one example, the first dye fixative may be configured to partition preferentially
to the fabric surface such that the reactive functional group is available to react
with loose dyes adjacent the fabric surface.
[0144] The dye fixative composition may further include an oxidizing agent, such as hydrogen
peroxide or a peroxide generating substance, and is preferably acidic, having a pH
less than 7. Preferably, the oxidizing agent is active at cold wash temperatures (e.g.
less than 85°F or 29.4°C). A non-limiting example of a suitable oxidizing agent includes
peracetic acid. In one example, the oxidizing agent may be a component of the dye
fixative formulation. In another example, the dye fixative may include chemicals that
interact with a component of the wash detergent composition to produce hydrogen peroxide,
non-limiting examples of which include an enzyme alcohol oxidase provided in the dye
fixative composition that reacts with ethanol present in the wash detergent composition
to produce hydrogen peroxide. In another example, the dye fixative formulation may
include acetic acid in an amount to provide the dye fixative formulation with a pH
less than 7.
[0145] Another example of a dye fixative composition includes a mixture of cationic surfactants
and nonionic surfactants that are capable of forming self-assembled monolayers on
the surface of the fabric. In one example, the mixture can include a mixture of cationic
surfactants and high HLB nonionic surfactants. The cationic surfactants may have a
zeta potential of greater than +20 mV. In one example, the zeta potential is preferably
between +20 mV and +40 mV. The nonionic surfactants may have an HLB in the range of
8-14. The cationic surfactants are capable of electrostatic interaction with the surface
of the fabric, such as a cotton fabric, for example, and may form a first monolayer
on the fabric surface which retains the dye at the fabric surface. The nonionic surfactants
may provide screening of the electrostatic repulsion between the head groups of the
cationic surfactants and further allow for a higher packing density of the assembled
surfactant layer on the fabric surface. The length of the alkyl chains of the surfactants
may be selected so as to provide a film having a predetermined thickness on the fabric
surface. In addition, a ratio of the concentration of the cationic and nonionic surfactants
may be selected to provide a desired packing density when assembled at the fabric
surface. For example, a lower packing density may allow for penetration of water through
the film to the fabric surface to facilitate the removal of soils from the fabric
surface, while still retaining the dye at the fabric surface. Alternatively, the packing
density may be selected so as to provide little to no water penetration of the film.
[0146] An example of a dye absorber composition according to an embodiment of the invention,
which may be used according to any of the methods described herein, includes a combination
of cationic and nonionic dye absorbers. There are a variety of different dye types
with different surface charges. For example, direct and acid dyes generally are negatively
charged while disperse and vat dyes are typically neutral under conditions normally
found in a wash liquid during a wash cycle in a clothes washer. The dye absorbers
of the composition may be selected to accommodate the various types of loose dye that
may bleed during a cycle of operation.
[0147] The cationic dye absorber component may include a water soluble cationic absorber,
examples of which are well known, such as polyvinylpyrrolidone. In another example,
the cationic dye absorber may include a zwitterionic dye absorber that becomes cationically
charged depending on conditions in solution in the treating chamber. The cationic
dye absorber component may also include a surfactant system comprising one or more
cationic surfactants configured to be present in the treating liquid when applied
to the laundry at a concentration above the critical micelle concentration (CMC) of
the surfactants. Cationic surfactants above the CMC may interact with acid and direct
dyes such that loose dye, for example dye that has transferred to other fabrics in
the load, which is not removed by a long chain cationic polymeric dye absorber, may
be removed by the cationic surfactants. Non-limiting examples of suitable cationic
surfactants include cetyltrimethylammonium bromide (CTAB) and cetylpyridnium bromide
(CPB).
[0148] The nonionic dye absorber component may include emulsifiers to absorb disperse and
vat dyes in solution. In one example, the emulsifier may be a surfactant system. In
one example, the surfactant system includes one or more nonionic surfactants having
an HLB in the range of 8 to 18 and capable of forming micelles between 10 to 40 °C
in an aqueous solution. Preferably, the nonionic surfactants are configured to be
present in the treating liquid when applied to the laundry at a concentration above
the CMC of the surfactants. An exemplary surfactant system may also include a block
co-polymer. In another example, the surfactant system may additionally or alternatively
include one or more zwitterionic or amphoteric surfactants. In yet another example,
the emulsifier may additionally or alternatively include host-guest complexes, such
as cyclodextrin, for example.
[0149] In another example, the emulsifier of the nonionic dye absorber component may be
in the form of colloidal particulates which form a Pickering emulsion. In general,
colloidal particulates are considered as changing the interfacial energy to form stable
emulsions of dye molecules in the liquid, rather than changing the surface tension
of the liquid. Colloidal particulates, such as nano-crystalline cellulose, silica,
particulates with positively charged functional groups, clay or silica-covered particles,
for example, can act as Pickering emulsions to complex with and suspend dye molecules
in solution.
[0150] The dye absorber composition may also include additional adjuncts, non-limiting examples
of which include chelators and builders, such as EDTA and STPP.
[0151] Figure 15 illustrates a method 600 for removing dye that is loose in solution or
has transferred to other fabric in the laundry load which may be used with the dye
absorber composition just described including a combination of cationic and/or nonionic
dye absorber components. The method 600 may be used with the wash cycle 10, other
wash cycle, or as a separate cycle of operation. The method 600 may be implemented
during a cycle of operation to remove loose dye that has transferred in the currently
running cycle. Alternatively, the method 600 may be used to remove loose dye that
has transferred in a previously run cycle. The method 600 includes treating the laundry
with a wash liquid including at least one surfactant and optionally enzymes, such
as a laundry detergent, to lift soils from the fabric at 602, such as may occur during
a main wash phase of a wash cycle. Following treatment with a wash liquid at 602,
the laundry load may be rotated at high speeds to extract the wash liquid, which includes
the detergent composition and soil which has been lifted from the laundry, from the
laundry load at 604.
[0152] At 606 the laundry may be treated with a dye absorber composition. In one exemplary
embodiment, the dye absorber composition may include a combination of the cationic
and nonionic dye absorber components described above. The dye absorber composition
may optionally include zwitterionic dye absorber components, as described above, without
the addition of additional anionic surfactants and/or enzymes (e.g. no additional
laundry detergent is added).
[0153] The dye absorber composition may include at least one water soluble cationic dye
absorber, a surfactant system comprising at least one surfactant and an emulsifier.
The at least one water soluble cationic dye absorber may include a polymeric dye absorber,
such as polyvinylpyrrolidone, or a zwitterionic dye absorber that becomes cationically
charged depending on conditions in solution in the treating chamber, for example.
The surfactant system may include cationic and/or nonionic surfactants above the CMC.
Non-limiting examples of suitable cationic surfactants include cetyltrimethylammonium
bromide (CTAB) and cetylpyridnium bromide (CPB). Non-limiting examples of suitable
nonionic surfactants include surfactants having an HLB in the range of 8 to 18 and
capable of forming micelles between 10 to 40 °C in an aqueous solution
[0154] The emulsifier may include a Pickering emulsion to complex with dyes in solution
or that may have transferred to other fabrics. In one example, the emulsifier component
may include cationic colloidal particulates capable of forming Pickering emulsions
to complex with loose acid and direct dyes present in solution or that may have transferred
to other fabrics. Additionally, or alternatively, the surfactant system may include
nonionic surfactants present above the CMC to complex with loose disperse and vat
dyes in solution or that may have transferred to other fabrics. In another example,
the emulsifier component may include a host-guest complex. In yet another example,
the emulsifier component may include a surfactant system comprising at least one surfactant
present at a concentration above the CMC of the at least one surfactant.
[0155] The dye absorber treatment phase 606 may include mechanical agitation to facilitate
removal of loose dyes, such as loose dyes that may have transferred onto light or
white colored fabrics. In this manner the dye absorber treatment phase 606 may be
considered a dye removal or dye scrubber phase in that dye absorbers are supplied
to the laundry to complex with dyes for removal from the laundry load. While the dye
absorber treatment phase 606 is described for use with the composition including a
combination of cationic and nonionic dye absorbers described above, it will be understood
that the dye absorber treatment phase 606 may be used with other dye absorber compositions
in a similar manner. In addition, while the dye absorber composition is described
in the context of the method 600, the composition may be used with other methods.
[0156] The concentration of one or more of the surfactants in the dye absorber composition
may be monitored during the treatment phase 606 to maintain the concentration above
the CMC for that particular surfactant. The concentration may be monitored using one
or more sensors or may be determined empirically by the controller using pre-programmed
algorithms and based on information related to the amount of laundry, the volume of
liquid supplied during the cycle of operation, the amount of absorber composition
supplied and/or the concentration of the dye absorber composition supplied. The concentration
may be controlled by controlling the dosage of the surfactant and/or controlling an
amount of water supplied to the treating chamber. For example, if the concentration
is too high above the CMC, additional water may be added to dilute the surfactant
concentration. In another example, if the concentration is too low, additional dye
absorber composition may be added to increase the surfactant concentration.
[0157] The amount of treating composition to supply to the treating chamber during the treatment
phase 606 may be based on the amount of treating chemistry provided to the dispenser
and/or based on an amount of laundry in the treating chamber. The amount of laundry
may be determined during a load amount determining phase that may be part of the method
600 or part of the cycle of operation used with the method 600. In one example, the
laundry treating appliance may use the load detection phase 22 described above with
respect to Figure 1 or any other suitable load detection method to determine the amount
of laundry. In another example the load amount may be determined based on input by
the user related to the load amount. In yet another example, the amount of treating
composition can be supplied based on an amount of liquid supplied to the treating
chamber to achieve the desired concentration of surfactants in the treating liquid
during the treatment phase 606.
[0158] At 608 the treatment liquid applied at 606 may be extracted from the laundry. This
may include draining treatment liquid collected in a sump of the clothes washer so
that it is no longer recirculated back onto the laundry and may optionally include
spinning the laundry at high speeds to facilitate the extraction of liquid from the
laundry. The dye absorber treatment at 606 and extraction at 608 may be repeated one
or more times and may be considered part of a dye removal or dye scrubber phase to
remove dye that is loose in solution and/or has transferred to other fabric in the
laundry load implemented as part of a rinse phase of a wash cycle or independent of
a rinse phase of a wash cycle. Following the extraction at 608, a final rinse may
be implemented at 610. The final rinse may include additional dye absorber and optionally
other rinse agents, such as a fabric softener, for example. Alternatively, the final
rinse may include water or a rinse liquid which includes rinse agents, such as a fabric
softener. If the final rinse at 610 includes dye absorber, the final rinse may be
implemented with mechanical agitation of the laundry load; if the final rinse at 610
does not include dye absorber, the final rinse may be restricted to only mechanical
motion which does not facilitate relative fabric-to-fabric motion, which may facilitate
dye transfer.
[0159] Figure 16 illustrates a method 650 for inhibiting dye transfer during a wash cycle
which includes treatment of the laundry with a dye transfer inhibiting composition
including a fabric softener and a dye absorber composition. The dye absorber composition
may include the dye absorber composition described above which includes a combination
of cationic and nonionic dye absorber components or some other dye absorber composition.
The fabric softener may include at least one cationic small chain polymer and/or at
least one silicone-based polymer which is capable of acting as a dye fixative. The
method 650 may be used with the wash cycle 10, with another wash cycle or as a separate
cycle of operation.
[0160] The method 650 begins with treating the laundry with a first dose of the dye inhibitor
composition at 652. At 654, the laundry may be washed according to a wash phase of
a selected cycle of operation with a wash liquid that includes at least one surfactant
and optionally enzymes, such as a wash liquid containing a laundry detergent composition,
to lift soils from the fabric. At 656, a second dose of the dye inhibitor composition
may be supplied to the treating chamber for treating the laundry. The second dose
of the dye inhibitor may be dispensed during a rinse phase to replenish fabric softener
which may have been removed from the laundry during the wash phase at 654. The second
dose of dye absorbers may facilitate removal of transferred loose dyes during the
rinse phase.
[0161] While not meant to be limited by any theory, the softener component of the dye transfer
inhibiting composition may form a thin film on the surface of the fabric from the
electrostatic interaction of the positively charged fabric softener and the cellulose
substrate that may fix or retain loose dyes on the surface of the laundry. The dye
absorbers may be provided in the composition to complex with loose dyes in solution
that may have been released from the surface of the laundry fabric. Some surfactants,
especially those containing anionic functional groups, may increase the release of
dyes from the fabric surface into solution during treatment with a laundry detergent
including such surfactants. The presence of the fabric softener, which may act as
a dye fixative to fix dyes at the surface of the laundry, in combination with dye
absorbers available for complexing with loose dyes, may decrease the rate of release
of dyes from the fabric surface and the subsequent dye transfer that may occur during
washing with a laundry detergent.
[0162] Figure 17A illustrates a method 700 for facilitating distribution of a dye fixative
on a laundry load. Dye fixatives may interact electrostatically with fabrics resulting
in localized spots of high concentration of dye fixative and non-uniform distribution
on the laundry items. For example, cationic dye fixatives can interact electrostatically
with the cellulose of cotton fibers, making uniform distribution of the dye fixative
on the fabric difficult. Uniform distribution of the dye fixative on the fabric facilitates
inhibition of dye transfer from the fabric surface. The method 700 may utilize a dye
fixative having a characteristic which may be adjusted or manipulated in order to
control a strength of the interaction between the dye fixative and a fabric surface
so as to facilitate the desired distribution, dye fixing and optional fixative removal.
The method 700 may be used with the wash cycle 10 of Figure 1 or any other suitable
wash cycle.
[0163] The strength or degree of interaction between a charged molecule, such as a cationic
dye fixative, and a charged surface, such as a cotton fiber surface, may be controlled
by adjusting the potential of the molecule and/or the surface. Zeta potential is a
measure indicative of a potential of a charged material in solution. Solution conditions,
such as pH, ionic strength, temperature and pressure can affect the measured zeta
potential of a material. The method 700 may be used with a dye fixative having a tunable
or adjustable zeta potential which may be controlled to provide a desired degree of
interaction between the dye fixative and a laundry surface.
[0164] The method 700 may begin at 702 with distributing a dye fixative to the laundry.
Distributing the dye fixative may include supplying a treating composition comprising
at least one dye fixative to wet or saturate the laundry. The treating composition
may be configured to provide an essentially neutrally charged dye fixative. As used
herein, a neutrally charged dye fixative is a dye fixative having a zeta potential
near zero, preferably within ± 10 mV. Providing a neutrally charged dye fixative to
the laundry may provide a more uniform distribution of the dye fixative to the laundry
by minimizing the electrostatic attraction between the dye fixative and the fabric
surface. Minimizing the electrostatic attraction between the dye fixative and the
fabric surface during the distributing at 702 may inhibit the formation of localized
spots of high concentration of dye fixative by allowing the dye fixative to spread
or distribute on the fabric surface before becoming strongly attracted to the surface.
[0165] Once the dye fixative has been distributed to the laundry, it is desirable to increase
the strength of the interaction between the dye fixative and the fabric surface in
order for the dye fixative to remain associated with the fabric surface and to interact
with dye molecules associated with the fabric to inhibit transfer or bleeding of the
dye molecules from the surface. Thus, at some predetermined point following the distribution
of the dye fixative, at 704 the zeta potential of the dye fixative may be changed
such that an electrostatic interaction between the dye fixative and the fabric surface
and/or dye molecules associated with the laundry fabric increases.
[0166] Depending on the nature of the dye fixative and the fabric surface, the zeta potential
of the dye fixative may be increased or decreased such that the electrostatic attraction
between the dye fixative and the fabric surface increases. In the case of a cationic
dye fixative and a cotton fabric, the zeta potential of the dye fixative may be increased
to increase the electrostatic attraction between the dye fixative and the cotton fabric.
The zeta potential of the dye fixative may be changed by altering the pH, ionic strength,
temperature and/or pressure of the fluid within which the dye fixative is dissolved
or suspended. For example, the pH may be changed to a desired pH by adding a suitable
pH buffer or using electrolysis to alter the pH, as discussed further below. In another
example, the ionic strength of the fluid may be changed by providing a salt or salt
solution to the fluid. Non-limiting examples of salts that may be used to adjust the
ionic strength include sodium chloride, sodium sulfate, and ammonium sulfate.
[0167] At 706, the dye fixative may be removed from the fabric surface, such as by changing
the zeta potential of the dye fixative again to facilitate removal of the dye fixative
from the fabric surface. For example, typically, it is desirable to have a dye fixative
associated with the laundry fabric during a wash phase in a cycle of operation to
inhibit dye transfer during the wash phase. As discussed previously, elements such
as the detergent, temperature, amount of liquid and mechanical energy used during
the wash phase may promote or facilitate dye transfer during the wash phase, thus
making it desirable to use a dye fixative to inhibit dye transfer. However, it may
not be desirable to leave the dye fixative on the laundry at the end of the cycle
of operation. Thus, following the wash and/or a rinse phase or stage, the dye fixative
may be removed prior to the end of the cycle of operation. The zeta potential may
be changed in the same or a different manner than described above at 704. To facilitate
removal of the dye fixative, the strength of the electrostatic attraction between
the dye fixative and laundry fabric is decreased, which may make it easier to rinse
off the dye fixative using a rinse liquid, for example. In one example, the strength
of the electrostatic attraction may be decreased by changing the zeta potential of
the dye fixative back to zero, preferably ± 10 mV, to make it easier to rinse away
the dye fixative.
[0168] Figure 17B illustrates an exemplary embodiment of the method 700 for facilitating
distribution of a dye fixative on a laundry load in the context of a pH tunable dye
fixative. In the example illustrated in Figure 17B, the electrostatic interaction
between the dye fixative and the fabric surface may be controlled by adjusting the
pH of the liquid in which the dye fixative is dissolved or suspended in. The method
710 may begin at 712 with treating the laundry with a pH tunable dye fixative in a
treating liquid at a first pH. A pH tunable dye fixative may refer to a polymer whose
surface charge changes depending on the pH of the solution. The first pH may correspond
to a pH at which the dye fixative is minimally charged, i.e. near the isoelectric
point of the dye fixative. An exemplary class of pH tunable dye fixatives includes
polymers having allylamine, vinylamine, acrylamide, ethylenimine, or lysine based
monomers or functional groups, poly(4-vinylpyridine), poly(2-vinylpyridine), poly(N,N-dimethylaminoethylmethacrylate),
poly(2-diethylaminoethyl methacrylate), poly(N,N-diakyl aminoethyl methacrylate),
poly(L-lysine), or chitosan.
[0169] An example of a suitable pH tunable dye fixative would be a dye fixative having a
zeta potential of approximately ±10 mV at pH > 8 and a zeta potential of greater than
20 mV at pH < 6. For this exemplary dye fixative, the treating liquid at 712 may have
a pH of approximately 8 or greater so as to provide a minimally charged or neutral
dye fixative, to facilitate uniform distribution of the dye fixative to the fabric
surface of the laundry, as discussed above.
[0170] At 714, the pH of the treating liquid may be decreased to a second pH which corresponds
to a pH at which the majority of the dye fixative is charged. This may include adding
liquid, such as a detergent, for example, to the treating liquid to bring the pH down
to the second pH or, alternatively, the treating liquid supplied at 712 may be drained
and fresh treating liquid at the desired second pH may be supplied to the laundry.
Alternatively, electrolysis may be used to alter the pH. Electrolysis of the liquid
produces an acid aqueous solution and an alkaline aqueous solution that may be used
to change the pH of the wash bath. An example of using electrolysis in a domestic
appliance is disclosed in
U.S. Pub. No. 2013/0026046 to Sanville, et al., filed July 6, 2011, entitled "On Site Generation of Alkalinity Boost for Ware Washing Applications".
For the exemplary dye fixative described above, the second pH may be about 6 or less.
Decreasing the pH to a value such that the majority of the dye fixative molecules
are charged may facilitate fixing of the dye fixative to the fabric surface, which
may promote the inhibition of dye transfer. The charged dye fixative molecule may
have a stronger electrostatic bond with the fabric surface such that a dye fixative
film or layer is formed on the surface of the fabric that inhibits the release of
dye from the fabric surface.
[0171] The laundry may then be washed according to a wash phase of a selected cycle at 716.
The pH of the wash liquid at 716 may be controlled such that the pH remains below
the first pH. Above the first pH, the dye fixative molecules become uncharged or neutral,
decreasing the strength of the bond between the dye fixative, the fabric surface and
the dye, which may increase the amount of dye released from the fabric surface.
[0172] Following the laundry wash phase at 716, the laundry may be treated with a rinse
liquid having a pH greater or equal to the first pH to again minimize the charge of
the dye fixative molecules at 718 to facilitate removal of the dye fixative from the
laundry. Neutralizing the dye fixative molecules in this manner may decrease the strength
of the interaction between the dye fixative and a charged fabric surface, such as
cellulose, making it easier to remove the dye fixative from the surface of the laundry.
Treating the laundry at 718 with a liquid at a pH greater than or equal to the first
pH may be done multiple times during a rinse phase of a cycle of operation or a single
time during a final rinse of the rinse phase. The dye fixative removal phase at 718
may be implemented in the presence of dye absorbers to complex with loose dyes in
solution to inhibit dye transfer during removal of the dye fixative.
[0173] An optional final rinse at 720 may be implemented to bring the pH down to at or below
neutral such that the laundry fabrics are not significantly alkaline at the end of
the cycle to improve the feel of the fabric. For example, the final rinse at 720 may
include a rinse with fresh water from the water supply.
[0174] The pH, ionic strength, temperature and/or pressure to provide a dye fixative with
the desired characteristic, such as the desired zeta potential, is based on the dye
fixative and characteristics of the treating liquids used during the cycle of operation
and may be determined empirically or using one or more formulas. Any combination of
environmental characteristics, such as pH, ionic strength, temperature or pressure
may be adjusted to provide the desired zeta potential of the dye fixative and thus
provide a desired strength of interaction between the dye fixative and the fabric
surface. For example, while the method 710 is described in the context of altering
the pH, it will be understood that the method 710 may also include adjusting the ionic
strength of the liquid at 714 or 718. In addition, while the methods 700 and 710 are
discussed in the context of changing the zeta potential of the dye fixative, it will
be understood that the zeta potential of the fabric surface may also be changed in
order to facilitate distribution or removal of the dye fixative from the laundry.
For example, rinsing the laundry with a rinse liquid having a high salinity may provide
the fabric surface with salt ions which may provide an electrostatic screen or shield
to reduce the attraction between the fabric surface and the dye fixative.
[0175] Figure 18 illustrates a method 800 for treating a laundry load with a dye fixative
during a wash cycle. The method 800 may be used with the wash cycle 10 of Figure 1
or any other suitable wash cycle. In one example, the method 800 may be used during
the pre-wash phase 14 of the wash cycle 10.
[0176] Many dye fixatives are charged molecules that interact electrostatically with the
fabric surface and the dye to fix or retain the dye at the fabric surface. Thus, the
presence of dye fixatives on the fabric surface may provide the fabric surface with
a charged layer that may undesirably attract other substances to the fabric surface.
For example, typical dye fixatives for use with cotton fabric and negatively charged
acid or direct dyes are positively charged cationic molecules. When the cationic dye
fixatives bond with the fabric surface, the fabric surface may present a more positively
charged surface than the untreated fabric surface. This positive charge may attract
negatively charged substances in solution to the fabric surface. For example, many
soils are negatively charged and thus may be attracted to the positively charged dye
fixative layer on the surface of the fabric. This may result in soils that have been
lifted from the laundry during washing or soils that the laundry comes into contact
with during use, depositing on the fabric to a greater extent than if the charged
dye fixative layer was not present.
[0177] The method 800 provides a method by which the charge of a dye fixative layer present
on the fabric surface may be changed or masked so as to minimize the attraction of
undesirable substances, such as soils, to the fabric surface. At 802 a dye fixative
layer having a first surface charge may be formed on the fabric surface. Formation
of the dye fixative may be implemented by supplying a dye fixative composition to
the laundry which is electrostatically attracted to one or more fabric surfaces of
the laundry. For example, for cotton fabrics dyed with acid or direct dyes, the dye
fixative will likely be a cationic dye fixative. Non-limiting examples of suitable
cationic dye fixatives include dye fixatives containing functional groups selected
from the group consisting of primary, secondary, and tertiary amines and their salts,
and quaternary ammonium and phosphonium salts, such as poly diallyl dimethyl ammonium
chloride (DADMAAC) and poly(acrylamide-co-diallyldimethyl ammonium chloride), polyacrylamide,
and polyethyleneimine. Non-limiting examples of suitable cationic dye fixatives include
those available under the trade name Sandofix SWE or WA, Sandolec CS, CL, WS, or CT,
and Cartafix WE (all available from Clariant), a cationic methylene guanidine based
dye fixative (commercially available under the trade name Retayne™ from G&K Craft
Industries), and those available under the trade name Sera® Fast CT (available from
Dystar).
[0178] At 804 the surface charge of the fabric dye fixative layer may be modified to neutralize
or change the charge of the fabric dye fixative layer. Modifying the fabric dye fixative
layer may include supplying a surface charge modifying agent having an electrostatic
charge opposite that of the fabric dye fixative layer to the laundry in the treating
chamber. The surface charge modifying agent may be attracted to the fabric-dye fixative
layer and preferentially distribute to the fabric surface. The surface charge modifying
agent may be supplied in an amount sufficient to neutralize the charge of the fabric-dye
fixative such that the overall charge of the fabric surface is near neutral. Alternatively,
the amount of surface charge modifying agent may be sufficient to provide the surface
of the fabric with an overall surface charge that is different than surface charge
of the fabric in the absence of the surface charge modifying agent.
[0179] In the example in which a cationic dye fixative is applied at 802, the surface charge
modifying agent may be an anionic polymer. Non-limiting examples of suitable anionic
polymers include polymers containing sulfonic or carboxylic groups having a molecular
weight above 200 kDa and a zeta potential between 0 to -20 mV in pure solution, although
other polymers having negatively charged functional groups may also be used. Non-limiting
examples of commercially available anionic polymers include Syntan, Nylofast® (available
from Clariant), and Sera Fast® NHF (available DyStar). The anionic polymers may be
supplied such that the surface charge of the fabric is negative rather than positive.
A negatively charged surface may be more likely to repel or inhibit the deposition
of negatively charged soils compared to a positively charged cationic dye fixative
layer. The anionic polymers may also provide the additional feature of acting as a
dye fixative on acid nylon fabrics.
[0180] Alternatively, the surface charge modifying agent may include small anionic compounds.
Non-limiting examples of suitable small anionic compounds include polymers having
functional sulfonate, carboxylate and/or acrylic acid functional groups and having
a molecular weight between 5-50 kDa. The small anionic compounds may interact with
the cationic dye fixative layer on the fabric surface to dissipate the positive charge
on the fabric such that the overall surface charge is near neutral. The small and
polar nature of the anionic agents may facilitate more uniform distribution of the
anionic agents through the treating liquid.
[0181] Subsequent treatment of the fabric item at 806, such as drying in a clothes dryer
following the end of the wash cycle, may be modified based on the type of surface
charge modifying agent applied to the fabric surface. For example, if a sulfonate
polymer is used as the surface charge modifying agent, the subsequent drying cycle
should be limited to a temperature below 130°F (54.4°C). The recommended drying temperature
may be communicated to the user through the user interface or may be automatically
communicated by the clothes washer to the dryer, in a manner similar to that described
below in method 1500 of Figure 26.
[0182] In yet another example, the surface charge modifying agent may include a saline solution.
The saline solution may be supplied to the laundry in the treating chamber to mask
the charge of the dye fixative layer and interrupt electrostatic attraction between
the charged dye fixative layer on the fabric and charged substances in the treating
liquid. In the example of direct dyes, these types of dyes often have low wash fastness,
i.e. are prone to bleeding when washed, because they are normally present as anionic
molecules with the sodium counter-ion dissociated in an aqueous solution, such as
a wash liquid, which increases hydrophilicity of the direct dye, and thus the solubility
of the dye in the wash liquid. Adding additional sodium ions into the solution may
shift the equilibrium of the system such that less sodium counter-ions dissociate
from the dye, making the dye molecules have an overall neutral charge and making the
dyes less soluble in the wash liquid. The concentration of sodium may vary depending
on the amount of direct dye in the wash liquid. In one example, the sodium ions may
be provided by adding sodium chloride and/or sodium sulfate at a sodium concentration
of about 50 g/L.
[0183] Additional examples of substances suitable for use as the surface charge modifying
agent include polyelectrolytes capable of forming layer by layer polymer films, non-limiting
examples of which include poly(acrylic acid), poly(methacrylic acid), polyethyleneimine,
poly(allylylamine hydrochloride), poly(acryllamide-2-methyl-propane sulfonate), poly(3-sulfopropyl
methacrylate), poly(styrene sulfonate), poly(N,N,N-trimethyl-2-methacryloyl ethyl
ammonium) bromide, poly(vinyl sulfate), poly(diallyldimethylammonium chloride), and
poly(4-vinyl-N-methylpyridinium iodide).
[0184] Figure 19 illustrates an exemplary dye fixative treatment method 850 for treating
a load of laundry with a cationic dye fixative. The method 850 may be implemented
as part of the pre-wash phase 14 of the wash cycle 10, as part of any other suitable
cycle of operation, or as a separate cycle. While the method 850 is described in the
context of treatment with a cationic dye fixative, it will be understood that the
method 850 may be implemented in a similar way for treatment with an anionic dye fixative
through the use of an appropriate surface charge modifying agent for anionic dye fixatives.
[0185] The method 850 may begin with assuming that the user has loaded a load of laundry
into the treating chamber and selected a cycle of operation that includes treatment
of the laundry with a dye fixative. At 852 the laundry may be pre-wet with rinse water.
The wetting phase at 852 may be the same as the pre-wetting phase 12 of cycle 10 or
different. As described above, pre-wetting the laundry with water prior to the application
of the dye fixative may facilitate more uniform distribution of the dye fixative on
the fabrics by lowering interfacial driving forces and reducing a rate of fabric penetration
and/or a rate of attachment of the dye fixative.
[0186] At 854 the laundry may be treated with a treating liquid including a cationic dye
fixative. The amount of cationic dye fixative may be based on an amount of laundry
and/or a type of fabric of the laundry. Any suitable automatic or manual method for
determining an amount and/or type of fabric of the laundry known in the art or described
herein may be used. Alternatively, the amount of cationic dye fixative may be a default
amount based on the selected cycle of operation or the amount of treating chemistry
provided by the user. Uniform distribution of the cationic dye fixative through the
laundry load may further be facilitated by applying mechanical energy to the laundry,
such as by tumbling or agitating the laundry load.
[0187] At 856, unbound or free cationic dye fixative, i.e. cationic dye fixative that is
not bound to the fabric surface, may be removed. Removing the free cationic dye fixative
may include draining cationic dye fixative that has collected in the sump of the clothes
washer. The laundry may be optionally spun at 856 to facilitate extraction of dye
fixative from the laundry for collection in the sump and subsequent draining. Alternatively,
fresh water may be added as a rinse prior to spinning and draining.
[0188] At 858, the laundry may be treated with a treating liquid including a surface charge
modifying agent which may be followed by a draining phase with optional laundry spin
to facilitate extraction of liquid at 860. The amount of surface charge modifying
agent to add may be determined in a similar or different manner to the amount of the
cationic dye fixative added. In one example, the amount of surface charge modifying
agent may be based on the amount of cationic dye fixative supplied to the laundry
at 854. Free surface charge modifying agent may be removed at 860 in a manner similar
to that described above at 856 for removing the cationic dye fixative. Following removal
of free surface charge modifying agent, the cycle of operation may continue to the
next phase of the selected cycle at 862. When the method 850 is used with the pre-wash
phase 14 of the wash cycle 10, the main wash phase 16 may follow the removal of free
surface charge modifying agent at 860.
[0189] In addition to providing dye fixatives to the fabric surface to inhibit dye transfer,
it may be desirable under certain circumstances to also remove dye fixative from the
fabric surface without facilitating dye transfer. For example, dye fixative may build
up on the fabric surface over time from multiple treatments with a dye fixative. The
dye fixative on the fabric may attract soils which may give the fabric a dirty or
dingy appearance.
[0190] In one example, the dye fixative may be configured to release from the fabric surface
upon exposure to predetermined conditions. Many dye fixatives are surfactants containing
a positively charged head group and non-polar tail. A surfactant-based dye fixative
may include a fatty acid tail that has a low melting temperature such that when heated
in a dryer or treated with hot water, the dye fixative melts out of the fabric surface.
Alternatively, the dye fixative may include a pH sensitive head group which changes
it charge under certain pH conditions, which may promote partitioning of the dye fixative
away from the surface. The pH of the treating liquid may be changed at a predetermined
point in the cycle to trigger the pH sensitive head group of the dye fixative to change
its charge and release from the fabric surface.
[0191] In another example, the dye fixatives may be actively removed from the surface of
the fabric, such as by using nanoparticles to shear off or remove at least a portion
of the fixative such that the dye fixative releases from the fabric surface. Alternatively,
enzymes may be introduced which may alter the fabric surface such that the dye fixative
releases from the fabric. In yet another example, the fabric surface may be excessively
charged to repel the dye fixative from the fabric surface, such as by adding salts,
such as sodium chloride.
[0192] The removal of the dye fixative may be performed at the end of a cycle to remove
dye fixative applied in the present cycle and additional dye fixative which may have
remained on the fabric after preceding cycles. Alternatively, the dye fixative may
be removed at the beginning of a cycle, such as during a pre-wash phase, for example,
The dye fixative may be removed at the beginning of the cycle to provide a relatively
dye fixative-free fabric surface which may be subsequently treated with additional
dye fixative. In this manner, the amount of dye fixative on the fabric surface may
be controlled and limited, inhibiting the build-up of dye fixative on the fabric surface
over time.
[0193] Figure 20 illustrates a method 1000 for treating new laundry items. As used herein
a new laundry item refers to a laundry item that is being washed by the user for the
first time. The new laundry item may be an unused laundry item or a used laundry item
that has not been previously washed by the user. The method 1000 may be used for treating
a single laundry item, multiple new laundry items or a combination of new laundry
items and previously washed laundry items.
[0194] The method 1000 begins at 1002 with receipt by the clothes washer controller of an
input indicative of a new laundry item for treatment by the clothes washer. The input
may include a user selecting the new laundry item cycle or indicating the load contains
a new laundry item through the user interface. Alternatively, the controller may receive
the input when a new laundry item is detected by the clothes washer. A new laundry
item may be detected optically, through radio frequency, or based on one or more predetermined
conditions being met. Optical detection may include optically scanning a label provided
on the laundry item, such as a bar code, detecting absorbance and/or transmittance
of light emitted from a light source, or taking an image or video of the laundry item.
Radio frequency detection may include receipt of information from an RFID tag provided
on the laundry item by a suitable RFID reader provided on the clothes washer. Certain
conditions, such as selection of a small load cycle or detection of a small load amount
may also indicate a new laundry item.
[0195] Upon receipt of the input indicative of a new laundry item, the controller may automatically
initiate a new laundry item cycle or prompt the user to select a new laundry item
cycle. At 1004, the new laundry item cycle may begin and a treatment may be supplied
based on the selected new laundry item cycle. At 1006 a wash and/or a rinse phase
may be modified. At 1008 the clothes washer may optionally provide feedback to a user
regarding an outcome of the "New Garment" cycle or recommendations for further laundry
item care.
[0196] Figure 21 illustrates an exemplary method 1020 for treating new laundry items in
a first wash cycle for a dyed laundry item. When a user goes to wash a new laundry
item for the first time, there may be concern as to whether the new laundry item will
bleed. In some cases a user will opt to wash the laundry item alone the first time
as a precaution to avoid potentially ruining other laundry items with dye transferred
from the new laundry item. In other cases, a user may inadvertently wash the new laundry
item with other laundry items and dye may transfer from the new laundry item to the
other laundry items in the load, potentially ruining these other laundry items. Some
laundry items are over-dyed and may bleed the first few times they are washed, but
after the first few washes, little to no additional bleeding may occur.
[0197] The method 1020 may be used to provide a user with information as to whether a new
laundry item is suitable for washing with mixed loads or should be washed alone and
optionally to provide a treatment to inhibit dye transfer.
[0198] The method 1020 may begin at 1022 with receipt by the controller of an input indicative
of a new laundry item, as described above at 1002 of the method 1000 of Figure 20.
While the method 1020 is described in the context of a single item, it will be understood
that the method 1020 may be used with multiple items. If multiple items are treated
at the same time according to the method 1020, the multiple items should be similarly
colored, such as multiple jeans, to avoid an undesirable dye transfer event.
[0199] At 1024 an optional dye transfer inhibitor may be supplied to the laundry item. The
dye transfer inhibitor may be a dye fixative that may be supplied to the laundry item
according to any of the methods described herein. Alternatively, the dye fixative
may be applied as the temperature of the treating liquid is increased. Increasing
the temperature may facilitate distribution of the dye fixative on the fabric surface
of the laundry item, increase complexing of the dye fixative and fabric, and also
facilitate bleeding of loose dyes which may be subsequently drained away. At the end
of the dye fixative supply phase, unabsorbed dye fixative may be removed by draining
treating liquid collected in the sump and optionally spinning the laundry items to
extract treating liquid.
[0200] At 1026, the laundry item may be washed according to a modified wash phase. Because
the laundry items are new items, it may be assumed that they are not heavily soiled
and thus removing soils is not a primary concern during the wash phase at 1026, and
the wash phase 1026 may therefore be quicker than a normal wash phase. The wash phase
at 1026 may include supplying a laundry detergent composition and an additive at a
predetermined concentration and at a predetermined temperature to facilitate removal
of loose dyes from the laundry item. For example, the laundry detergent composition
may be supplied to the laundry such that the concentration of surfactants is below
the CMC to facilitate removal of loose or excess dye. The additive may be a dye absorber
which may further facilitate removal of loose dyes. The laundry item may also be tumbled
or agitated to facilitate releasing loose dyes from the surface of the laundry item
through mechanical action. Because not all dyes are removed using the same methods,
a combination of dye fixative, laundry detergent concentration, temperature, dye absorbers
and mechanical action may be used to facilitate removal of loose/excess dye across
a broader range of dye and fabric types.
[0201] At 1028 the laundry item may be rinsed according to one or more rinse phases. A presence
of a dye in the rinse liquid may be determined at 1030 within the treating chamber,
which may also include liquid that was previously in the treating chamber. Dye in
the rinse liquid may be considered released dye in that the dye is no longer associated
with a laundry item, but is present in solution in the rinse liquid. A suitable sensor
system may be provided for determining the presence of a dye in the rinse liquid,
non-limiting examples of which include optical sensor systems which may be used to
perform UV/Vis absorbance/fluorescence spectroscopy or a conductivity sensor. For
example, a UV/Vis absorbance/fluorescence system may provide an output representative
of a sensed spectral absorbance and/or fluorescence of the treating liquid. It will
also be understood that when referring to absorbance herein, transmittance, which
is related to absorbance, may be used as an alternative to absorbance or in order
to determine the absorbance. The sensor system may output a signal indicative of a
presence of dye, including an amount of dye, in the rinse liquid. The sensor system
may sense the dye and output the signal continuously or intermittently throughout
the rinse phase 1028 or at one or more predetermined stages of the rinse phase 1028,
such as the end of the final rinse, for example.
[0202] The controller may receive the output signal indicative of the presence of a dye
from the sensor system and determine whether the output signal satisfies a predetermined
threshold at 1032. This may include comparing the Abs/F characteristic to a predetermined
reference value that may be a range of reference values, an upper threshold or a lower
threshold. In the embodiment of Figure 21, the threshold is an upper threshold. If
the output signal does not satisfy the threshold, the controller may determine at
1034 that the laundry item is suitable for washing with mixed loads in an un-sorted
wash cycle and provide feedback to the user through the user interface that the laundry
item may be washed in mixed loads in future wash cycles. In this manner the output
signal may indicate a dye inhibited condition.
[0203] The cycle may then be completed at 1038. Optionally, at 1042, a dye fixative may
be supplied to the laundry item to facilitate inhibiting dye transfer in a future
wash cycle and/or during use. The term "satisfies" the threshold is used herein to
mean that the variation satisfies the predetermined threshold, such as being equal
to, less than, or greater than the threshold value. It will be understood that such
a determination may easily be altered to be satisfied by a positive/negative comparison
or a true/false comparison. For example, a less than threshold value can easily be
satisfied by applying a greater than test when the data is numerically inverted.
[0204] If the output signal does satisfy the threshold, the controller may determine at
1036 that dye is present in the rinse liquid and that the laundry item is not ready
for washing with mixed loads and should be washed in a sorted wash cycle. In this
manner the output signal may indicate a non-inhibited condition, which may indicate
that the laundry is not dye stable, i.e. dye may transfer from the laundry item to
other surfaces during laundering and/or use. The method then returns to 1026 to repeat
the modified wash phase 1026, rinse phase 1028 and determining the presence of dye
in the wash liquid at 1030. The controller may be programmed to repeat the steps 1026,
1028, 1030 and 1032 a predetermined n number of times. If it is determined that dye
has been determined to be present greater than n number of times at 1036, the cycle
may end at 1038 and the controller may provide feedback to the user at 1040 that the
laundry item should not be washed with mixed loads. For many laundry items, washing
a predetermined number of times, usually around 3, is sufficient to remove enough
loose dye to decrease the risk of a dye transfer event to an acceptable level. However,
if a laundry item continues to bleed dye after multiple washings, the method 1020
may be completed and the user may be provided with feedback as to the dye transfer
status of the laundry item. Optionally, at 1044, a dye fixative may be supplied to
the laundry item to facilitate inhibiting dye transfer in a future wash cycle and/or
during use.
[0205] The feedback provided to the user at 1034 and 1040 may be provided through text communicated
through a user interface or with one or more illuminated indicators. For example,
the user interface may be provided with a ready for mixed loads indicator which is
illuminated green when the laundry item is ready for washing with mixed loads and
red when the laundry item is not ready for washing with mixed loads. In another example,
the user interface may communicate whether the laundry item is ready for washing with
mixed loads and other additional care information, such as recommendations for further
treatments.
[0206] In another example, the method 1020 may be configured for use in treating jeans,
which are typically dyed with vat dyes. Rather than adding a dye fixative at 1024,
an oxidizing agent may be added during the wash phase 1026 to facilitate oxidation
of any unoxidized vat dyes and render them water insoluble, which may increase their
wash fastness and decrease dye transfer. The method 1020 for use with jeans may be
provided to the user as a cycle option when the user selects a jeans-only cycle.
[0207] While the method 1020 is described as including a dye determination process, the
method 1020 may be used in a similar manner without determining the presence of dye.
For example, the wash and rinse phases 1026 and 1028 may be repeated a predetermined
number of times that may be set automatically by the controller or selected by the
user.
[0208] Figure 22 illustrates another exemplary method 1050 for treating new laundry items
in a first wash cycle. The method 1050 may be used with new laundry items to remove
treatments or finishes from the items or to apply additional treatments or finishes
to the items that are more suitable for applying to laundry items that have not been
worn or used. For example, the method 1050 may be used to remove a sizing agent from
the laundry, if desired by the user, prior to wearing or using the laundry item. In
another example, the method 1050 may be used to apply a stain repellant finish to
the laundry item. The application of a stain repellant may lock-in stains present
on the laundry item and thus it is preferable to apply a stain repellant prior to
wearing or using the garment. However, some consumers wear or use the item before
washing the item for the first time. Thus, as will be described below, the method
1050 may include a wash phase prior to the application of the stain repellant to remove
soils or stains that may have occurred prior to the first wash.
[0209] The method 1050 may begin at 1052 with receipt by the controller of an input indicative
of a new laundry item as described above at 1002 of the method 1000 of Figure 20.
While the method 1050 is described in the context of a single item, it will be understood
that the method 1050 may be used with multiple items.
[0210] The method 1050 may include a main wash phase 1056 and a rinse phase comprising one
or more rinses at 1062 which may be modified based on a treating agent supplied to
the laundry items during one or more of first, second and/or third treatment supply
phases 1054, 1058, and 1060. While three treatment supply phases are illustrated,
it will be understood that more treatment phases may be used depending on the treatment
to be applied.
[0211] In one example, the method 1050 may be used to remove a sizing agent from a new laundry
item. Some users may deem the presence of a sizing agent on the laundry item as undesirable.
For removal of a sizing agent, the main wash phase 1056 may include providing mechanical
action, such as tumbling or agitation, and a wash liquid at a predetermined temperature
and including a laundry detergent composition at a predetermined concentration to
facilitate removal of the sizing agent. The second and optionally third treatment
supply phases 1058 and 1060 may include additional mechanical action and application
of wash liquid configured to facilitate removal of the sizing agent. For example,
the wash liquid may be heated to the highest recommended temperature for that item
and/or the concentration of a laundry detergent in the wash liquid may be increased
to 1-3 times the recommended dosage. Because the laundry item is new, soil removal
is not the primary concern and the wash phase 1056 and treatment phases 1058 and 1060
may be configured to optimize removal of the sizing agent rather than the removal
of soil and stains, as in a typical normal wash cycle.
[0212] In another example, the method 1050 may be used to provide the new laundry item with
a fabric finish. In this example, the main wash 1056 may include providing mechanical
action, such as tumbling or agitation, and a wash liquid at a predetermined temperature
and including a laundry detergent composition at a predetermined concentration. The
main wash phase 1056 may be a quick or light wash phase because the laundry item is
new and therefore does not likely have a high degree of soiling or staining. At 1058
one or more fabric finish treating agents may be supplied to the laundry item. The
fabric finish agents may be supplied at a predetermined concentration and temperature
depending on the agent. The fabric finish agent may be supplied at a high concentration
in a low water volume with circulation to facilitate distribution of the fabric finish
agent.
[0213] In one example, the fabric finish agent supplied in the second supply treatment 1058
may prepare the laundry item for a fabric finish agent supplied in the third supply
treatment phase 1060. The second and/or third treatment supply phases 1058 and 1060
may include a temperature ramp profile that may activate or set the fabric finish.
Alternatively, or in addition, the user may be provided with feedback at 1064 through
a user interface to set/activate the finish in a high heat cycle in a clothes dryer
at the end of the wash cycle. In yet another example, the clothes washer may communicate
the recommended temperature setting automatically to the dryer.
[0214] Non-limiting examples of fabric finish agents that may be supplied during the treatment
supply phases 1058, 1060 include stain repellants, UV blockers, soil release agents,
insect repellant, flame retardant, water repellant, moisture wicking refresh agents,
wrinkle release agents and wrinkle repellants.
[0215] In yet another example, the method 1050 may be used to treat a new laundry item that
is being wash for the first time by the user, but may have been previously owned/used,
such as used clothing purchased from a second-hand or thrift shop or yard sale. At
1056, the laundry items may be washed in the main wash phase to remove soils and stains
by applying mechanical action and a wash liquid containing a laundry detergent composition.
At 1058 a treatment composition comprising an enzyme, such as cellulase, may be supplied
to the laundry. The cellulase may act as a fabric polisher, removing pilling, which
may rehabilitate the appearance of the laundry item and make it look "newer".
[0216] The feedback provided to the user at 1064 may be provided through text communicated
through a user interface or with one or more illuminated indicators. For example,
the user interface may be provided with an indicator that changes color depending
on the status of the treatment. In another example, the user interface may communicate
care information, such as recommendations for further treatments. For example, the
user interface may recommend dryer settings or future wash settings for the item.
[0217] Often, after fabric articles are washed, a user then dries the fabric articles. This
may be problematic if dye has been transferred during the washing of the fabric articles
as the drying may thermoset the transferred dye on the fabric articles, given the
drying temperatures of contemporary clothes dryers. Figure 23 illustrates one example
of a clothes dryer 1100, which includes a cabinet 1112 in which may be provided a
controller 1114 that may receive input from a user through a user interface 1116 for
selecting a cycle of operation and controlling the operation of the clothes dryer
1100 to implement the selected cycle of operation. The user interface 1116 may be
operably coupled with the controller 1114 and may provide an input and output function
for the controller 1114. The cabinet 1112 may be defined by a front wall 1118, a rear
wall 1120, and a pair of side walls 1122 supporting a top wall 1124. A chassis may
be provided with the walls being panels mounted to the chassis. A door 1126 may be
hingedly mounted to the front wall 1118 and may be selectively movable between opened
and closed positions to close an opening in the front wall 1118, which provides access
to the interior of the cabinet 1112.
[0218] A rotatable drum 1128 may be disposed within the interior of the cabinet 1112 between
opposing stationary front and rear bulkheads 1130, 1132, which, along with the door
1126, collectively define a treating chamber 1134 for receiving fabric items for treatment.
As illustrated, and as may be the case with most clothes dryers, the treating chamber
1134 may not be fluidly coupled with a drain. Thus, any liquid introduced into the
treating chamber 1134 may not be removed merely by draining.
[0219] The drum 1128 may include at least one lifter 1129. In most dryers, there may be
multiple lifters 1129. The lifters 1129 may be located along an inner surface of the
drum 1128 defining an interior circumference of the drum 1128. The lifters may facilitate
movement of the laundry 1136 within the drum 1128 as the drum 1128 rotates.
[0220] The drum 1128 may be operably coupled with an actuator in the form of a motor 1154
to selectively rotate the drum 1128 during a cycle of operation. The coupling of the
motor 1154 to the drum 1128 may be direct or indirect. As illustrated, an indirect
coupling may include a belt 1156 coupling an output shaft of the motor 1154 to a wheel/pulley
on the drum 1128. A direct coupling may include the output shaft of the motor 1154
coupled with a hub of the drum 1128.
[0221] An air flow system may be provided to the clothes dryer 1100. The airflow system
supplies air to the treating chamber 1134 and exhausts air from the treating chamber
1134. The supplied air may be heated or not. The air flow system may have an air supply
portion that may form, in part, a supply conduit 1138, which has one end open to ambient
air via a rear vent 1137 and another end fluidly coupled with an inlet grill 1140,
which may be in fluid communication with the treating chamber 1134. A heater 1142
may lie within the supply conduit 1138 and may be operably coupled with and controlled
by the controller 1114. If the heater 1142 may be turned on, the supplied air will
be heated prior to entering the drum 1128.
[0222] The air flow system may further include an air exhaust portion that may be formed
in part by an exhaust conduit 1144. A lint trap 1145 may be provided as the inlet
from the treating chamber 1134 to the exhaust conduit 1144. An actuator in the form
of a blower 1146 may be fluidly coupled with the exhaust conduit 1144. The blower
1146 may be operably coupled with and controlled by the controller 1114. Operation
of the blower 1146 draws air into the treating chamber 1134 as well as exhausts air
from the treating chamber 1134 through the exhaust conduit 1144. The exhaust conduit
1144 may be fluidly coupled with a household exhaust duct (not shown) for exhausting
the air from the treating chamber 1134 to the outside of the clothes dryer 1100.
[0223] The air flow system may further include various sensors and other components, such
as a thermistor 1147 and a thermostat 1148, which may be coupled with the supply conduit
1138 in which the heater 1142 may be positioned. The thermistor 1147 and the thermostat
1148 may be operably coupled with each other. Alternatively, the thermistor 1147 may
be coupled with the supply conduit 1138 at or near to the inlet grill 1140. Regardless
of its location, the thermistor 1147 may be used to aid in determining an inlet temperature.
A thermistor 1151 and a thermal fuse 1149 may be coupled with the exhaust conduit
1144, with the thermistor 1151 being used to determine an outlet air temperature.
[0224] A moisture sensor 1150 may be positioned in the interior of the treating chamber
1134 to monitor the amount of moisture of the laundry in the treating chamber 1134.
One example of a moisture sensor 1150 may be a conductivity strip. The moisture sensor
1150 may be operably coupled with the controller 1114 such that the controller 1114
receives output from the moisture sensor 1150. The moisture sensor 1150 may be mounted
at any location in the interior of the dryer 1100 such that the moisture sensor 1150
may be able to accurately sense the moisture content of the laundry. For example,
the moisture sensor 1150 may be coupled with one of the bulkheads 1130, 1132 of the
drying chamber 1134 by any suitable means.
[0225] A dispensing system 1157 may be provided to the clothes dryer 1100 to dispense one
or more treating chemistries to the treating chamber 1134 according to a cycle of
operation. As illustrated, the dispensing system 1157 may be located in the interior
of the cabinet 1112 although other locations are also possible. The dispensing system
1157 may be fluidly coupled with a water supply 1168. The dispensing system 1157 may
be further coupled with the treating chamber 1134 through one or more nozzles 1169.
As illustrated, nozzles 1169 are provided to the front and rear of the treating chamber
1134 to provide the treating chemistry or liquid to the interior of the treating chamber
1134, although other configurations are also possible. The number, type, and placement
of the nozzles 1169 are not germane to the invention.
[0226] As illustrated, the dispensing system 1157 may include a reservoir 1160, which may
be a cartridge, for a treating chemistry that may be releasably coupled with the dispensing
system 1157, which dispenses the treating chemistry from the reservoir 1160 to the
treating chamber 1134. The reservoir 1160 may include one or more cartridges configured
to store one or more treating chemistries in the interior of the cartridges. A mixing
chamber 1162 may be provided to couple the reservoir 1160 to the treating chamber
1134 through a supply conduit 1163. Pumps such as a metering pump 1164 and delivery
pump 1166 may be provided to the dispensing system 1157 to selectively supply a treating
chemistry and/or liquid to the treating chamber 1134 according to a cycle of operation.
The water supply 1168 may be fluidly coupled with the mixing chamber 1162 to provide
water from the water source to the mixing chamber 1162. The water supply 1168 may
include an inlet valve 1170 and a water supply conduit 1172. It may be noted that,
instead of water, a different treating chemistry may be provided from the exterior
of the clothes dryer 1100 to the mixing chamber 1162.
[0227] The treating chemistry may be any type of aid for treating laundry, non-limiting
examples of which include, but are not limited to, water, fabric softeners, sanitizing
agents, de-wrinkling or anti-wrinkling agents, and chemicals for imparting desired
properties to the laundry, including stain resistance, fragrance (e.g., perfumes),
insect repellency, and UV protection.
[0228] The clothes dryer 1100 may also be provided with a steam generating system 1180,
which may be separate from the dispensing system 1157 or integrated with portions
of the dispensing system 1157 for dispensing steam and/or liquid to the treating chamber
1134 according to a cycle of operation. The steam generating system 1180 may include
a steam generator 1182 fluidly coupled with the water supply 1168 through a steam
inlet conduit 1184. A fluid control valve 1185 may be used to control the flow of
water from the water supply conduit 1172 between the steam generating system 1180
and the dispensing system 1157. The steam generator 1182 may further be fluidly coupled
with the one or more supply conduits 1163 through a steam supply conduit 1186 to deliver
steam to the treating chamber 1134 through the nozzles 1169. Alternatively, the steam
generator 1182 may be coupled with the treating chamber 1134 through one or more conduits
and nozzles independently of the dispensing system 1157.
[0229] The steam generator 1182 may be any type of device that converts the supplied liquid
to steam. For example, the steam generator 1182 may be a tank-type steam generator
that stores a volume of liquid and heats the volume of liquid to convert the liquid
to steam. Alternatively, the steam generator 1182 may be an in-line steam generator
that converts the liquid to steam as the liquid flows through the steam generator
1182.
[0230] It will be understood that the details of the dispensing system 1157 and steam generating
system 1180 are not germane to the embodiments of the invention and that any suitable
dispensing system and/or steam generating system may be used with the clothes dryer
1100. It may also within the scope of an embodiment of the invention for the clothes
dryer 1100 to not include a dispensing system or a steam generating system.
[0231] Figure 24 is a schematic view of the controller 1114 coupled with the various components
of the clothes dryer 1100. The controller 1114 may be communicably coupled with components
of the clothes dryer 1100 such as the heater 1142, blower 1146, thermistor 1147, thermostat
1148, thermal fuse 1149, thermistor 1151, moisture sensor 1150, motor 1154, inlet
valve 1710, pumps 1164, 1166, steam generator 1182 and fluid control valve 1185 to
either control these components and/or receive their input for use in controlling
the components. The controller 1114 may also be operably coupled with the user interface
1116 to receive input from the user through the user interface 1116 for the implementation
of the drying cycle and provide the user with information regarding the drying cycle.
For example, the user interface 1116 may receive information from a user that a dye
transfer event has occurred and may provide an indication of a dye transfer event
to the controller 1114. The user interface 1116 may be provided having operational
controls such as dials, lights, knobs, levers, buttons, switches, and displays enabling
the user to input commands to a controller 1114 and receive information about a treatment
cycle from components in the clothes dryer 1100 or via input by the user through the
user interface 1116. The user may enter many different types of information, including,
without limitation, cycle selection and cycle parameters, such as cycle options as
well as information regarding the load to be dried including the type of laundry and
the type of dye transferred. Any suitable cycle may be used. Non-limiting examples
include, Casual, Delicate, Super Delicate, Heavy Duty, Normal Dry, Damp Dry, Sanitize,
Quick Dry, Timed Dry, and Jeans.
[0232] The controller 1114 may also be communicably coupled with a data communicator 1190
for receiving information from a washing machine and outputting information to the
controller 1114. For example, the data communicator 1190 may provide an indication
of a dye transfer event to the controller 1114. The data communicator 1190 may wirelessly
communicate with the washing machine and/or may be hard-wired to communicate with
the washing machine. The wireless communication may be any variety of communication
mechanism capable of wirelessly linking with other systems and devices and may include,
but is not limited to, packet radio, satellite uplink, Wireless Fidelity (WiFi), WiMax,
Bluetooth, ZigBee, 3G wireless signal, code division multiple access (CDMA) wireless
signal, global system for mobile communication (GSM), 4G wireless signal, long term
evolution (LTE) signal, Ethernet, or any combinations thereof. It will also be understood
that the particular type or mode of wireless communication is not critical to this
invention, and later-developed wireless networks are certainly contemplated as within
the scope of embodiments of this invention. Alternatively, the data communicator 1190
may be incorporated into the controller 1114 such that the washing machine may be
communicably coupled with the controller 1114.
[0233] The controller 1114 may implement a treatment cycle of operation selected by the
user according to any options selected by the user and provide related information
to the user. The controller 1114 may also include a central processing unit (CPU)
1174 and an associated memory 1176 where a set of executable instructions comprising
at least one user-selectable cycle of operation may be stored. One or more software
applications, such as an arrangement of executable commands/instructions may be stored
in the memory and executed by the CPU 1174 to implement the one or more treatment
cycles of operation.
[0234] In general, the controller 1114 will effect a cycle of operation to effect a treating
of the laundry in the treating chamber 1134, which may or may not include drying.
The controller 1114 may actuate the blower 1146 to draw an inlet air flow 1158 into
the supply conduit 1138 through the rear vent 1137 when air flow may be needed for
a selected treating cycle. The controller 1114 may activate the heater 1142 to heat
the inlet air flow 1158 as it passes over the heater 1142, with the heated air 1159
being supplied to the treating chamber 1134. The heated air 1159 may be in contact
with a laundry load 1136 as it passes through the treating chamber 1134 on its way
to the exhaust conduit 1144 to effect a moisture removal of the laundry. The heated
air 1159 may exit the treating chamber 1134, and flow through the blower 1146 and
the exhaust conduit 1144 to the outside of the clothes dryer 1100. The controller
1114 continues the cycle of operation until completed. If the cycle of operation includes
drying, the controller 1114 determines when the laundry may be dry. The determination
of a "dry" load may be made in different ways, but may be often based on the moisture
content of the laundry, which may be typically set by the user based on the selected
cycle, an option to the selected cycle, or a user-defined preference.
[0235] Further, the controller 1114 may receive an indication of a dye transfer event for
the laundry to be dried from the user interface 1116 or the data communicator 1190.
Based on such a determination, the controller 1114 may control operation of one or
more specific drying actions or cycles based on the determined dye transfer event
to limit any damage to the fabric items that the transferred dye may cause. For example,
the controller 1114 may control operation of the blower 1146, the heater 1142, and
the operation of the rotatable drum 1128 based on the determined dye transfer event.
The controller 1114 may also be configured to provide an indication on the user interface
1116 of the determined dye transfer event.
[0236] Figure 25 illustrates a method 1300 for determining a dye transfer event and controlling
operation of the clothes dryer based thereon. More specifically, the method begins
at 1302 by the controller 1114 receiving as an input an indication of a dye transfer
event for the laundry to be dried. For example, the controller 1114 may receive an
indication from the user interface 1116 when a user inputs that the dye transfer event
has occurred. A washing machine used to wash the laundry may alert the user to the
dye transfer or the user may notice that dye has transferred. The washing machine
may also indicate to the user to select a specific dryer cycle, including for example
a delicate cycle or dye transfer cycle, or may indicate to the user to select a specific
temperature or dryness level. Alternatively, the controller 1114 may receive a communication
from a washing machine that the dye transfer event has occurred. For example, clothes
washer 50, 450 and 2050 may all be configured to communicate that a dye transfer event
has occurred. Such a communication is described in more detail below with respect
to method 1500. It will be understood that such an indication of a dye transfer event
may be received via the data communicator 1190 from the washing machine and that the
data communicator 1190 may provide an indication of the dye transfer event to the
controller 1114. Alternatively, the controller 1114 may be configured to receive the
indication directly from the washing machine. Regardless of whether the data communicator
1190 or the controller is communicably coupled with the washing machine, it will be
understood that the communication with the washing machine may be a wireless communication
and/or a hard-wired communication.
[0237] After a dye transfer event has been indicated at 1302, the controller 1114 may control
the implementation at 1304 of the automatic cycle of operation of the clothes dryer
based on the indication of the dye transfer event. This may include the controller
1114 implementing one or more specific drying actions or cycles, which may include,
among other things, selecting a specific cycle of operation, setting one or more parameters
of the cycle of operation, including keeping the drying temperature below the dye
set or thermoset temperature, skipping or adding a phase to the cycle of operation,
terminating the cycle of operation, and adding a treating chemistry to prevent the
dye from setting. For example, a specific dye transfer cycle may be utilized to limit
the drying of the fabric items so that the transferred dye does not thermoset. The
implementation of the one or more specific drying actions or cycles may occur regardless
of what cycle of operation is selected by a user on the user interface 1116. For example,
a user may select a gentle dry cycle and the controller 1114 will instead operate
the clothes dryer 1100 under the dye transfer cycle. Alternatively, the controller
1114 may limit the user from selecting any alternative cycles or drying actions such
the one or more specific drying actions or cycles may be the only options allowed
for the user to select.
[0238] By way of non-limiting example, controlling the implementation of the automatic cycle
of operation of the clothes dryer 1100 including specific drying actions or cycles
may include limiting temperatures during the cycle of operation. This may include
limiting the drying temperature within the treating chamber 1134 to below 140°F (60°C).
For example, the cycle of operation may be executed such that temperatures within
the rotatable drum 1128 do not exceed 135°F (57°C). By way of further example, this
may include utilizing drying temperatures between 115°F (40°C) and 125°F (52°C) for
a first half of the cycle of operation or until the residual moisture content (RMC)
of the fabric items is determined to be about 30% and then utilizing drying temperatures
between 95°F (35°C) and 105°F (41°C) from that point until the end of the cycle. Further,
controlling operation of the clothes dryer 1100 may include limiting dryness achieved
during the cycle of operation. Typical cycles end when the RMC reaches between two
and four percent. Limiting the dryness during the implemented cycle where a dye transfer
has been indicated may include ending the cycle of operation when the RMC reaches
between 10% and 18%. Further still, controlling operation of the clothes dryer 1100
may include adjusting a rotation profile of a drum of the clothes dryer. This may
include lowering the revolutions per minute of the rotatable drum 1128, limiting the
time spent tumbling, not tumbling, etc. Any of the above or any combination of the
above may avoid hot spots within the load and over drying, either of which may thermoset
transferred dye.
[0239] It will be understood that the method may be flexible and that the method 1300 illustrated
is merely for illustrative purposes. For example, the method may include indicating,
on a user interface of the clothes dryer, information related to the dye where the
information includes at least one of: at least one action taken by the clothes dryer
in response to the determined dye transfer event, at least one consequence of the
at least one action taken by the clothes dryer, or indicating on the user interface
that the dye transfer event has been determined. It is also contemplated that the
input received by the controller 1114 may include information related to a type of
dye transferred and/or a type of laundry to be dried. Based on such additional information
the controller 1114 may be configured to control a drying temperature of the clothes
dryer to be below a thermoset temperature and such a thermoset temperature may be
determined based on the type of dye transferred and/or the type of laundry.
[0240] As briefly described above, the method may include communicating with a clothes washer
to determine if a dye transfer event has occurred. Figure 26 illustrates a method
1500 for communicating dye transfer information between a clothes washer and clothes
dryer and controlling operation of the clothes dryer based on the communicated dye
transfer information. The operation of the clothes dryer may then be controlled to
minimize further dye transfer or thermosetting of any transferred dye.
[0241] The method 1500 may begin with assuming that laundry has been loaded into the clothes
washer and is being treated according to a selected cycle of operation. At 1502 the
presence of a dye transfer event may be determined. A dye transfer event may be determined
automatically by the clothes washer or the clothes washer may determine a dye transfer
event manually based on user input. For example, the user may provide information
to the clothes washer through the user interface that identifies an item of the load
as known for dye bleeding and/or identifies an item of the load as new and/or brightly
or deeply colored, which may be suspected of bleeding. Alternatively, the user may
identify an item of the load as being new and/or of unknown dye bleeding status that
the user would like the clothes washer and/or dryer to treat as if a dye transfer
event occurred as a precaution.
[0242] Alternatively, a dye transfer event may be determined automatically one or more times
at predetermined points in the cycle of operation. The determination may be done continuously
or intermittently through the entire cycle of operation or during one or more phases
of the cycle of operation. In one example, the color of the wash liquid at different
stages of the wash phase of a cycle or at the end of the wash phase may be determined
using a suitable sensor system, such as a UV/Vis absorbance system, for example, to
determine whether the color of the wash liquid or a change in color of the wash liquid
indicates that a dye transfer event has occurred. In another example, the use of dye
fixatives and/or absorbers in the cycle, either automatically or based on manual input
by a user, may be used to determine that a dye transfer event has occurred.
[0243] In yet another example, the fabric item may include a label that communicates dye-related
information with the clothes washer. The fabric item may include an RFID tag or a
barcode that is readable by a suitable reader provided on the clothes washer. The
label may communicate information such as the type of dye(s) present in the fabric
item and the clothes washer controller may be programmed to determine whether the
dye(s) are likely to result in a dye transfer event.
[0244] The dye transfer event information may be communicated with the dryer at 1504 through
an appropriate connection between the clothes washer and the dryer or wirelessly,
such as through Bluetooth, for example, as described above with respect to Figure
24. In this manner the washing machine may provide an indication to the dryer that
a dye transfer event has occurred and the dryer may control or modify a subsequent
drying cycle based on the indicated dye transfer event information at 1506.
[0245] Similarly to the method 1300 described above, controlling the drying cycle may include
controller the implementation of the cycle of operation based on the indication of
the dye transfer event including modifying the drying cycle such that the temperature
remains at the lowest setting for that drying cycle, modifying the dryness end point
for the selected drying cycle to minimize heating of the fabrics at the end of the
cycle, and/or modifying the drum rotation profile for the selected drying cycle to
provide minimal agitation so as to not facilitate further dye transfer. Heating the
fabrics at too high of a temperature and/or for too long during a drying cycle may
thermoset dye that has transferred during the preceding wash cycle, which may prevent
removal of the transferred dye in a subsequent wash cycle. In one example, receipt
of a dye transfer event by the dryer may cause the dryer to prompt the user to select
a predetermined dye transfer cycle which includes one or more of these cycle modifications.
[0246] Figure 27 illustrates a method 1600 for inhibiting dye transfer in a wash cycle without
the use of dye fixatives or dye absorbers by controlling surface tension gradients
on the fabric surface of the laundry.
[0247] The method 1600 may begin by assuming that a user has loaded laundry into the treating
chamber and selected a cycle of operation. At 1602, the laundry may be pre-wet with
water only. In one example, the pre-wet phase may be implemented as described above
for the pre-wetting phase 12 of the cycle 10. Pre-wetting the fabrics may reduce the
interfacial tension between a wash liquid and the fabric surface when a wash liquid
is supplied to the laundry. Reducing the interfacial tension may reduce surfactant
penetration onto the laundry and thus reduce dye bleeding from the fabric. In a laundry
detergent composition, surfactants may penetrate the fabric and lift dyes from the
fabric surface. Anionic surfactants have been found to lift direct and acid dyes and
nonionic surfactants have been found to lift disperse dyes. Reducing the driving force
of surfactants to the fabric surface by pre-wetting the fabric may reduce this surfactant-induced
dye bleeding.
[0248] Following pre-wetting of the laundry at 1602, the laundry may be treated with a laundry
detergent composition at a concentration such that the surfactants are present at
concentrations slightly above their CMC. Surfactants at concentrations above the CMC
may provide surfactant micelles capable of absorbing dye released from the fabric
surface to inhibit dye transfer. The concentration of the surfactant may be controlled
and/or monitored in a manner similar to that described above with respect to method
600 of Figure 15. In one example, the concentration of the laundry detergent may be
controlled by controlling the dosage of the detergent and/or controlling an amount
of water supplied to the treating chamber with the detergent. If the surfactant concentration
is too high above the CMC, at 1606 additional water may be added to dilute the surfactant
concentration and the cycle may continue at 1608. The pre-wetting at 1602 and treating
with laundry detergent at 1604 may be implemented at cold water temperatures and with
minimal mechanical action to further inhibit dye transfer.
[0249] Figure 28 illustrates a method 1700 for removing dye fixative from laundry items.
Dye fixatives, in particular cationic dye fixatives, on laundry may attract soils,
which are often negatively charged, in the wash liquor during a wash cycle and during
use of the laundry item after laundering. The electrostatic attraction between the
cationic dye fixative and negatively charged soil may make the soil difficult to remove,
even during a wash cycle. This soil may also give the laundry a dingy or dulled appearance,
especially on white and light colored fabrics, which may increase over time as dye
fixative is applied multiple times to the laundry in subsequent wash cycles.
[0250] The method 1700 may be implemented as a wash cycle to remove absorbed dye fixative
and soil to whiten or brighten laundry items. The method 1700 may be implemented automatically
as part of a whitening or a brightening phase of a wash cycle or a whites only wash
cycle, for example. In another example, the method 1700 may be implemented based on
user selection of a cycle modifier option to selectively implement the method 1700
as part of a wash cycle. The method 1700 may begin with a wash phase 1702 which includes
supplying a hot wash liquid to the laundry items that includes a laundry detergent
and a basic agent to increase the pH of the wash liquid to a basic pH, preferably
pH >9. The temperature of the treating liquid is preferably at least 110°F (43°C)
or greater, but lower temperatures may also be used. Non-limiting examples of basic
agents include powdered alkaline build detergents, alkaline ingredients such as sodium
or ammonium hydroxide, and other buffer components, such as a buffer system formed
by sodium bicarbonate and sodium hydroxide, for example. Alternatively, the pH of
the wash liquid may be adjusted through electrolysis.
[0251] The alkaline wash liquid may be configured to provide an environment with a pH above
the pKa of the cationic dye fixative, which may decrease the adhesion force between
the dye fixative and the fabric, resulting in the release of the dye fixative from
the fabric. For example, a basic pH may facilitate removal of polyamine cationic dye
fixatives from the fabric, as described above at 718 of the method 710 of Figure 17B,
the embodiments of which may be used with the method 1700.
[0252] In one example, the supplying of heated, alkaline liquid and a detergent to the laundry
in the treating chamber may overlap as part of the wash phase 1702. Alternatively,
the wash phase 1702 may be divided into a dye fixative removal stage in which heated,
alkaline liquid is supplied to the laundry first followed by the addition of detergent
to the alkaline liquid to form a wash liquid as part of a wash stage. In this manner
the dye fixative removal stage may be implemented as a separate stage prior to any
wash stage in a selected cycle of operation.
[0253] The heating of the liquid, adjusting of the pH and addition of detergent may be done
in any order and may occur simultaneously or sequentially. In one example, the water,
basic agent, and detergent may be supplied to a tub of the clothes washer for heating
and mixing, such as in a sump area of the tub, prior to being sprayed onto the laundry
in the treating chamber by a recirculation system. Alternatively, any part of the
heating, adjusting the pH or mixing with a detergent may occur prior to entry into
the tub or treating chamber. For example, the water may be supplied from a hot water
supply or flowed through an in-line heater prior to being supplied to the tub or sprayed
directly onto the laundry in the treating chamber. In another example, the basic agent
may be mixed with the heated water as it is being supplied to the laundry in the treating
chamber, such as by adding the basic agent to the flow of heated water or flowing
the heated water through a mixing chamber where the heated water can be mixed with
the basic agent prior to being sprayed into the treating chamber.
[0254] The wash phase 1702 may include treating the laundry items with additional laundry
adjuncts, such as dye absorbers, oxidizing agents and/or optical brighteners. In one
example, the wash phase 1702 may be implemented with dye absorbers in a manner similar
to that described above for cycle 10 of Figure 1. The dye absorbers may be a mixture
of cationic and nonionic dye absorbers, such as those described above. The dye absorbers
may facilitate preferential distribution of the soil away from the cationic fixative
and fabric surface and into solution with the dye absorbers where they may subsequently
be removed. The oxidizing agents, such as hydrogen peroxide or a source of hydrogen
peroxide, for example, may be provided to decolorize soil on the laundry items and
may also oxidize the cationic dye fixative, which may facilitate solubilization of
the cationic dye fixative for subsequent removal.
[0255] During the wash phase 1702, the alkaline liquid and/or the wash liquid may be recirculated
through the treating chamber to move the liquid through the laundry to facilitate
removal of dye fixative from the laundry and cleaning of the laundry. Mechanical energy
may also be supplied to further facilitate removal of the dye fixative and cleaning
of the laundry, such as by rotating a drum defining the treating chamber and/or moving
a clothes mover within the treating chamber.
[0256] At 1704 a rinse phase may be implemented. The rinse phase may include one or more
rinses which may optionally include supplying dye absorbers during at least one of
the rinses. The rinse phase 1704 may be implemented in a manner similar to that described
above for cycle 10 of Figure 1 or the method 300 of Figure 9, which include the use
of dye absorbers.
[0257] Either or both of the wash and rinse phases 1702 and 1704 may be repeated one or
more times before ending the cycle at 1706. In one example, the number of times the
wash phase 1702 and/or rinse phase 1704 is repeated may be a predetermined number
of times programmed into control software associated with the controller. Alternatively,
the number of times the wash and/or rinse phases 1702/1704 are repeated may be set
by the user. Each of the wash and rinse phases 1702 and 1704 may include one or more
drain phases in which liquid is drained from the tub. The drain phases may optionally
include rotating the laundry at high speeds to facilitate extraction of liquid from
the laundry, followed by draining the extracted liquid from the tub.
[0258] In another example, the decision to repeat a wash and/or rinse phase 1702, 1704 may
be determined based on sensor output indicative of a presence of a dye fixative in
the wash and/or rinse liquid. The clothes washer may be provided with a suitable sensor
system to determine the presence of a dye fixative in the treating liquid. The sensor
system may be an optical-based sensor system such as a UV/Vis absorbance/reflectance
system, or a conductivity sensor system, for example. The sensor system may provide
an output to the controller indicative of a presence of a dye fixative in the wash
and/or rinse liquid. The controller may decide whether to repeat the wash and/or rinse
phase 1702, 1704 based on the output from the sensor system. The sensor system may
take sensor readings continuously or intermittently throughout the wash/rinse phases
1702, 1704 or at predetermined stages of the wash/rinse phases 1702, 1704.
[0259] Referring again to Figure 28, at 1708 a presence of a dye fixative in the wash liquid
may optionally be determined by the controller based on output received from the sensor
system during or at the end of the wash phase 1702. The controller may determine that
dye fixative is present if the output satisfies a predetermined threshold and repeat
the wash phase 1702. The wash phase 1702 may be repeated based on the determine presence
of a dye fixative a predetermined number of times or until the output does not satisfy
the threshold. If the output does not satisfy the predetermined threshold, then the
cycle may proceed to the next phase.
[0260] Optionally, the determination of the presence of a dye fixative may be used to modify
the wash phase 1702 each time the wash phase 1702 is repeated. For example, the controller
may use the output to determine an amount of dye fixative present in the wash liquid
and modify cycle parameters such as temperature of the wash liquid, pH of the wash
liquid, and/or an amount of a treating agent to add. In one example an amount of laundry
detergent and/or dye absorbers to supply during the wash phase 1702 may be determined
based on the amount of dye fixative detected in the wash liquid.
[0261] The method 1700 may be implemented automatically based on sensor output or based
on information received from the user. For example, the method 1700 may be implemented
automatically during a cycle of operation based on a determined presence of a dye
fixative. The determination of the presence of a dye fixative may include determining
the presence of a dye fixative in the wash or rinse liquid, in a manner similar to
that described above at 1708 and 1710 of Figure 28, or on the laundry items. Alternatively,
the presence of a dye fixative may be determined based on sensing the presence of
dye fixative in the dispenser. In one example, the presence of a dye fixative in the
dispenser may be determined using a suitable sensor configured to determine the presence
of a dye fixative in the treating liquid provided in the dispenser. Non-limiting examples
of a sensor include an optical or electrical sensor. In another example, the dye fixative
may be stored in a container which carries information regarding the presence of a
dye fixative that may be communicated with the controller of the appliance. In an
exemplary embodiment, the dye fixative may be provided in a dispenser cartridge which
carries information, such as a bar code, that can be read by a suitable sensor provided
in the appliance. In another example, the method 1700 may be implemented based on
cycle selections or cycle modifier selections made by the user through the user interface
of the clothes washer.
[0262] In an exemplary embodiment, the clothes washer may include a dye fixative removal
option that a user can select through the user interface to implement the dye fixative
removal cycle of method 1700 as part of a selected cycle of operation or as an independent
cycle. Additionally, or alternatively, the method 1700 may be implemented automatically
based on the selected cycle, such as a whites only cycle, or based on the phases of
the selected cycle, such as a wash cycle with a whitening phase, as described above.
In yet another example, the user may be prompted by the clothes washer to provide
information relating to the laundry item(s) dye fixative treatment status (e.g. the
item was previously treated in a dye fixative treatment cycle) and the clothes washer
may use this information to automatically implement the method 1700 as part of a selected
cycle of operation or as an independent cycle.
[0263] Alternatively, or additionally, a determination of a presence of a dye fixative may
optionally be determined following the rinse phase 1704 at 1710. The determination
at 1710 may be performed in a manner similar to that described above at 1708. If dye
fixative is determined to be present, either the wash phase 1702 or the rinse phase
1704 may be repeated a predetermined number of times or until the output satisfies
a threshold value.
[0264] Figure 29 illustrates a schematic of a vertical axis clothes washer, also sometimes
referred to as a top loader, 1850 that is similar to the clothes washer 50 of Figure
2 except that the clothes washer 1850 is illustrated as having a dispenser 1890 and
an optional heating system 1898. The elements in the clothes washer 1850 that are
similar to those of clothes washer 50 have been labeled with the prefix 1800. Only
those elements necessary for a complete understanding of the embodiments of the invention
are illustrated and it will be understood that the clothes washer 1850 may include
additional elements traditionally found in a clothes washer without deviating from
the scope of the invention.
[0265] The clothes washer 1850 may include a dispenser 1890 for dispensing a treating chemistry,
which may include water, into the treating chamber 1862 or tub 1854 through one or
more nozzles 1894. The dispenser 1890 may be any suitable single dose, multi-dose
or bulk-type dispenser and may include a treating chemistry storage compartment(s)
1892 and one or more dispensing pumps 1893 for pumping the treating chemistry from
the storage compartment 1892 to the nozzle 1894 for spraying into the treating chamber
1862. There may be one or multiple compartment(s) 1892, which may dispense solid or
liquid treating chemistries. One or more of the storage compartment(s) may receive
a removable cartridge containing the dispensing chemistry. Some of the compartment(s)
1892 may be a cup holding the treating chemistry, which is flushed by liquid, instead
of using the pump 1893, to dispense the treating chemistry from the compartment 1892.
The dispensing pump 1893 may pump the treating chemistry directly from the storage
compartment 1892 or, alternatively, the dispensing pump 1893 may pump the treating
chemistry to a mixing chamber (not shown) for mixing one or more treating chemistries,
which may include water from a water supply 1872, to form a treating chemistry mixture
prior to supplying the treating chemistry mixture to the treating chamber 1862. The
pump 1893 is preferably a metered pump, such as a piston pump, which is capable of
dispensing very precise volumes of treating chemistries at very precise flow rates.
[0266] Treating chemistry which collects in the sump 1858 may be pumped out through a household
drain 1878 by a pump 1876. Alternatively, the pump 1876 may recirculate liquid collected
in the sump 1858 back to the treating chamber 1862 through a recirculation conduit
1880 and a sprayer 1874. While a single pump 1876 is illustrated for preforming both
the drain and recirculation functions, separate pumps may be used.
[0267] The optional heating system 1898 is provided for heating the liquid used in the cycle
of operation and/or the treating chamber 1862. In this way, the temperature of the
liquid and/or laundry in the treating chamber 1862 may be raised to a desired temperature
for the cycle of operation. The heating system 1898 may be any suitable heating system
for the described purpose and is illustrated as a forced air system comprising a resistive
heating element 1898A and a fan 1898B, which are configured such that the fan 1898B
blows air over the heating element 1898A and the heated air is sent to the treating
chamber 1862. Alternatively, the heating system 1898 could be a heater located within
a liquid supply line or in the sump 1858 to heat the liquid that is applied to the
laundry in the treating chamber 1862. However, for the low liquid volumes used in
the embodiments described herein, there may be insufficient liquid volumes to fully
immerse a heater in the sump, making the forced air system more desirable.
[0268] Figure 30 illustrates a color care cycle 1900 for supplying a treating chemistry,
such as a color care agent, to laundry in the treating chamber 1862 during an automatic
cycle of operation. While the color care cycle 1900 is described in the context of
the clothes washer 1850, it will be understood that the cycle 1900 may be used with
any of the clothes washers described herein, such as clothes washer 50, 450 and 2050.
The color care cycle 1900 may be used to supply one or more color care agents to the
treating chamber 1862 for the preservation of laundry color and/or the inhibition
of a dye transfer event. While the color care cycle 1900 is described in the context
of supplying a fabric softener as the color care agent, the color care agent may include
alternate or additional treating chemistries, non-limiting examples of which include
one or more cationic surfactants, cationic polymers, emulsions, vesicles, micelles,
dye absorbers or dye fixatives or combinations thereof. The color care agent may be
provided to the treating chamber 1862 as a mixture and may include one or more additional
treating chemistries, non-limiting examples of which include water, fragrance and
colorants.
[0269] The color care cycle 1900 begins with assuming that the user has placed the laundry
for treatment into the treating chamber 1862, provided a treating chemistry that includes
a color agent to the dispenser 1890 and selected a cycle of operation that includes
the color care cycle 1900. The color care cycle 1900 may be an independent cycle or
part of another cycle of operation executed by the control software of the controller
1882.
[0270] The color care cycle 1900 may include an optional laundry load detection phase 1902
that may be used to determine an amount of laundry present in the treating chamber
1862. The amount of laundry may be qualitative or quantitative and may be determined
manually based on user input through the user interface 1884 or automatically by the
washing machine 1850 in a manner similar to that described for the laundry load detection
phase 22 of Figure 1.
[0271] The color care cycle 1900 includes a pre-wash phase 1904 which includes forming a
pre-wash mixture 1906 and supplying the thus formed pre-wash mixture to the treating
chamber 1862 at 1908. Following the pre-wash phase 1904, a wash phase 1910 may be
implemented in which a wash mixture is formed at 1912 and supplied to the treating
chamber 1862 at 1914. The wash phase 1910 may also include the application of mechanical
energy 1916 to the laundry in the treating chamber 1862 to treat the laundry and remove
soil from the laundry.
[0272] Forming the pre-wash mixture at 1906 may include combining a color care agent, such
as a composition that includes a fabric softener, and water to form a pre-wash mixture
having a predetermined concentration of fabric softener, which may include providing
a constant concentration of the color care agent. The dispensing pump 1893 may be
configured to dispense a controlled amount of fabric softener from the storage compartment
1892 to provide a predetermined concentration of fabric softener to the treating chamber
1862 throughout the supplying of the pre-wash mixture at 1908. In one example, the
dispensing pump 1893 may continuously or intermittently dose a predetermined portion
of the fabric softener stored in the storage compartment 1892 to a flow of water in
real time to form the pre-wash mixture. In another example, the dispensing pump 1893
may repeatedly pump a micro-dose of the fabric softener into a flow of water. Dosing
a predetermined portion of the fabric softener may be based on dosing a predetermined
amount of fabric softener and/or predetermined rate of fabric softener based on the
concentration of the fabric softener in the storage compartment 1892 and the desired
end concentration of fabric softener to be applied to the laundry in the treating
chamber 1862. In another example, the fabric softener and water can be supplied to
the sump 1858 at predetermined ratios or at predetermined rates to form a pre-wash
mixture having the desired end concentration for application to the laundry. An exemplary
ratio of fabric softener to water is 4 mL of fabric softener for every 1 L of water.
The thus formed pre-wash mixture may then be circulated from the sump 1858 to the
laundry in the treating chamber 1862 by the pump 1876 through the recirculation conduit
1880 and the sprayer 1874. In yet another example, the fabric softener may be combined
with another treating chemistry, such as water, in a mixing chamber to form a pre-diluted
concentrate that is then pumped into a flow of water or into the sump 1858 for mixture
with water also supplied to the sump 1858.
[0273] The pre-wash mixture may be formed at 1906 at a predetermined concentration that
is based on the amount of laundry in the treating chamber 1862, as determined at the
load detection phase 1902. The amount of pre-wash mixture formed at 1906 may also
be based on the amount of laundry and may be set so as to provide enough pre-wash
mixture to uniformly cover the laundry with the pre-wash mixture without oversaturating
the laundry. As used herein, oversaturating the laundry refers to a condition in which
the amount of water and/or fabric softener associated with the laundry is more than
is necessary to uniformly cover the surface of the laundry. Once the laundry is saturated
with liquid such that the laundry cannot absorb additional liquid, any additional
liquid that is added will either run-off the laundry or pool within folds or pockets
formed by the laundry items. For example, consider an exemplary embodiment in which
a load is to be treated with a pre-wash mixture including a dye fixative, such as
Retayne™. For an 8 lb (3.63 kg) load, 48 mL of a pre-wash dye fixative mixture would
oversaturate the load, whereas 32 mL of the pre-wash dye fixative mixture would provide
sufficient liquid to saturate and cover the laundry, such as when applied according
to the method 1900 as described below, for example, without oversaturating the load
and wasting the pre-wash dye fixative mixture.
[0274] Providing excess water and fabric softener to the laundry unnecessarily consumes
these resources. In addition, excess fabric softener may interact with treating chemistries,
such as laundry detergent, supplied during other portions of the cycle resulting in
an undesirable amount of an undesirable by-product, such as a precipitate. Thus, an
appropriate amount of fabric softener will be an amount that can cover the laundry
for the determined load size without the fabric softener precipitating with other
chemistries used during the cycle of operation. While it is desired that every surface
of the laundry be uniformly covered with fabric softener at the determined concentration
level, practically it is understood that this is not likely possible. Thus, it is
expected that a suitable amount may result in less than perfect coverage and a small
amount of precipitate which does not interfere with treating performance of the cycle
of operation is tolerable.
[0275] Referring now to Figure 31, one example of a treating chemistry supply method 1950
is illustrated, which may be used at 1908 of the cycle 1900 of Figure 30 for supplying
a pre-wash mixture to the laundry in the treating chamber 1862. While the method 1950
is described in the context of supplying a pre-wash mixture, it will be understood
that the method 1950 may be used to supply any suitable treating chemistry to the
laundry. The method 1950 may be used with the cycle 1900 or any other cycle in which
a treating chemistry is supplied to the laundry to provide uniform coverage of the
laundry without oversaturating the laundry with the treating chemistry. Further, while
the treating chemistry supply method 1950 is designed for a vertical axis machine,
it may be used in a horizontal axis machine.
[0276] In overview, the method 1950 initially supplies the pre-wash mixture to the tub 1854
to maintain the level of pre-wash mixture at a predetermined level. During the supply
of pre-wash mixture, the pre-wash mixture is recirculated while the drum 1860 is rotated
at a slow speed. The liquid level in the sump 1858 is checked to confirm that there
is sufficient liquid for continued recirculation. If not, the recirculation is stopped
until sufficient liquid is supplied for recirculation. Ultimately, a steady state
is reached where the liquid in the sump maintains a predetermined level while the
liquid is continuously recirculated and the supply of pre-wash liquid is terminated
while the recirculation is continued. The termination of the recirculation with drum
rotation may be based on time, which may be a function of the time to reach the steady
state.
[0277] In a specific implementation, the method 1950 may begin with an optional drain step
1952 in which liquid that has collected in the sump 1858 is drained by the pump 1876.
At 1954, water and fabric softener may be provided to the sump 1858 as a pre-formed,
pre-wash mixture or to form the pre-wash mixture, such as described above at 1906
of the cycle 1900, until the liquid level satisfies a predetermined threshold wl_max.
Providing the pre-wash mixture to the sump at 1954 may be considered a fill process.
The level of liquid in the sump 1858 may be determined in any suitable manner, such
as based on output from a pressure sensor located in the sump 1858, and is not germane
to the embodiments of the invention.
[0278] At 1956 recirculation of the liquid in the sump 1858 and rotation of the drum 1860
may begin. The recirculation and rotation of the drum 1860 may begin at the same time
or one may begin at some predetermined delay after the other. In one example, recirculation
may begin after the drum 1860 has been rotating for a predetermined period of time
or when the rotational speed of the drum 1860 reaches a predetermined speed. The filling
started at 1954 may continue for a predetermined period of time during recirculation
and rotation at 1956 or may be halted prior to beginning recirculation and/or rotation
at 1956. In one example, the fill process of 1954 continues as recirculation is started
and the drum 1860 starts to rotate to a predetermined speed, such as 26 rpm, for example.
The fill, recirculation and rotation may continue for a predetermined period of time,
such as 10 seconds, for example, before moving on to a liquid level determination
at 1958a, b.
[0279] Following the start of recirculation and rotation of the drum at 1956, the process
loops back and forth between 1958a and 1958b to determine if the liquid level wl in
the sump satisfies a pair of upper and lower threshold values, which in the exemplary
method 1950 correspond to 10 and 0.5. The upper and lower threshold values may correspond
to a height of liquid in the sump or an output from the pressure sensor representative
of the level of liquid in the sump 1858. The lower threshold value may correspond
to an amount of liquid in the sump 1858 that satisfies the pump 1876 by providing
a sufficient amount of liquid to decrease the likelihood of starvation of the pump
1876. As used herein, starvation with respect to a pump refers to when the pump inlet
draws in air, not just liquid. The upper threshold value may correspond to a desired
amount of liquid for completing the treating chemistry supply method. In one example,
the upper threshold value may correspond to a liquid level in the sump 1858 which
will satisfy the pump 1876 during recirculation of the liquid in the sump 1876 even
as some of the recirculating liquid is absorbed by the laundry. Prior to saturation
of the laundry with the liquid, as liquid is sprayed onto the laundry, the laundry
may absorb some of the liquid, thus the amount of liquid which collects in the sump
1858 after spraying will likely be less than the amount of liquid in the sump 1858
prior to the spraying.
[0280] If the liquid level wl in the sump is below the lower threshold value 0.5 at 1958a,
then recirculation is stopped at 1960 and the drum 1860 is rotated while continuing
to fill the sump 1858 with the pre-wash mixture until the liquid level satisfies the
upper threshold value 10 at 1962, at which point recirculation is started at 1964
and filling is stopped at 1966. At 1958b, if the liquid level in the sump 1858 goes
above the upper threshold value 10 before it drops below the lower threshold value
0.5, then the process stops filling at 1966.
[0281] At 1968, the pre-wash mixture has been provided to increase the liquid level wl in
the sump to satisfy the upper threshold value 10 while recirculation continues and
filling has been stopped and parameter t_0 is set. The drum 1860 may continue to rotate
at 26 rpm for the remainder of the process 1950. After t_0 is defined, the remainder
of the process 1950 relates to determining if the liquid level wl in the sump is staying
above a predetermined lower threshold level determined according to the relationship
wl<os-ts*(time-t_0).
[0282] Referring now to Figures 32A and B, graphs 2000 and 2002 of liquid level in the sump
over time for a large load and a small load, respectively are illustrated. The graphs
2000 and 2002 are illustrated for the purposes of discussion and do not represent
actual data. As liquid is provided to the sump 1858 during a fill process, the sump
liquid level increases. At a predetermined liquid level 2004, filling is stopped and
recirculation of the liquid in the sump 1858 is started. As the liquid is recirculated
onto the laundry and absorbed by the laundry, the liquid level in the sump 1858 begins
to decrease. The amount of time t
c that it takes for the liquid level to decrease to a predetermined level may vary
depending on characteristics of the laundry, such as the load amount and fabric type,
for example, as well as the speed of rotation of the drum 1860 during recirculation.
As illustrated in Figures 32A and B, the time t
c for a large load is smaller than the time t
c for a small load. Viewed another way, the rate of change of the liquid level in the
sump during recirculation (i.e. the slope) is faster for a large load than for a small
load. During recirculation, larger loads may absorb more water than small loads and
thus the liquid level in the sump 1858 for a large load will decrease faster than
an equivalent small load.
[0283] Figure 33 graphically illustrates the relationship between wl, os, ts, t_0 and t
c for the purposes of discussion only and is not meant to limit the embodiments of
the invention in any way. Graph 2006 illustrates the change in liquid level, lower
threshold and refill level over time for a single load during a filling and recirculation
process to cover the laundry with a pre-wash mixture. The pre-wash mixture may be
provided to the sump 1858 during a fill 2008 to increase the liquid level to a first
fill level 2010 at which point recirculation of the pre-wash mixture is started. The
point at which recirculation is started is time t_0. As the liquid is recirculated,
the liquid level in the sump 1858 decreases. When the liquid level in the sump reaches
a first lower threshold 2012, recirculation is halted and the filling process begins
again until the liquid level reaches a second fill level or refill level 2014. When
the liquid level in the sump reaches the refill level 2014, recirculation is started
and a new t_0 and lower threshold level wl 2016 is determined. As the liquid level
in the sump decreases during recirculation, when the liquid level reaches the lower
threshold level wl 2016, recirculation is stopped and the filling process begins again
until the liquid level reaches the second refill level 2018. The fill and recirculate
process may be repeated any number of times until the liquid level in the sump remains
above the lower threshold for a predetermined period of time. Each time the fill and
recirculate process is repeated, the lower threshold level may be varied, by changing
os and ts, based on the amount of time it took for the liquid level to drop below
the lower threshold level in the previous fill and recirculate process. The term os
is an offset value which corresponds to the lower threshold at time t_0; the term
ts is the target slope which corresponds to the rate at which the lower threshold
decreases. As the laundry becomes covered and saturated with the pre-wash mixture,
the amount of time it takes for the liquid level in the sump to decrease to the lower
threshold level increases.
[0284] Depending on the characteristics of the load, such as amount and fabric type, for
example, the liquid level in the sump may decrease at varying rates. The rate at which
the liquid level in the sump decreases affects how long it takes to reach the lower
threshold level, which is determined by the offset os and the target slope ts, illustrated
by lower limit 2020. The parameters os and ts may be determined experimentally or
based on empirical data for different load conditions to provide the desired degree
of coverage using a predetermined amount of resources and time.
[0285] In this manner, the supplying of the pre-wash mixture may be implemented adaptively
to supply enough pre-wash mixture to the laundry to provide a predetermined level
of coverage and saturation without oversaturating the load or using an excessive amount
of water and/or fabric softener. The amount of pre-wash mixture absorbed by the laundry
during a fill and recirculate process may be used to determine an amount of pre-wash
mixture to provide in a subsequent fill and recirculate process.
[0286] Referring again to Figure 31, at 1970, it may be determined if the liquid level wl
in the sump 1858 remained above the predetermined lower threshold level for a predetermined
period of time, such as 30 seconds. If the liquid level wl in the sump 1858 did not
remain above the lower threshold level for longer than 30 seconds, at 1972 it is determined
if the liquid level wl in the sump 1858 satisfies the relationship wl<os-ts*(time-t_0).
If the liquid level wl in the sump 1858 does not satisfy this relationship, then the
process loops back to 1970. If the liquid level wl in the sump 1858 does satisfy the
relationship, then recirculation is stopped at 1974, the refill level, os, ts and
lower threshold level are determined for the next fill at 1976 and recirculation process
based on the length of time it took for the liquid level wl to reach the previous
lower threshold level. The pre-wash mixture is provided to the sump 1858 at 1978 to
begin the refill process until the liquid level wl in the sump 1858 reaches the refill
level at 1980 and then recirculation is started again at 1964.
[0287] This process is repeated until it is determined at 1970 that the liquid level wl
in the sump 1858 remains above the lower threshold level for 30 seconds or more. The
process then advances to 1982 and the lower threshold level may be set to a predetermined
value, such as 0.5, for example. If the liquid level wl in the sump 1858 remains above
0.5, the process continues for a predetermined period of time before completion. In
the exemplary embodiment, if the liquid level wl remains above 0.5, the process continues
for 60 more seconds and then recirculation and drum rotation is stopped and the liquid
collected in the sump 1858 may optionally be drained at 1984 and the process completed
at 1986.
[0288] If the liquid level wl in the sump 1858 drops below 0.5 with at least 10 seconds
remaining in the process at 1988 and 1990, then the fill process is implemented for
a predetermined period time, such as 5 seconds at 1992, during which recirculation
and drum rotation continue. Optionally, if there is less than 10 seconds remaining,
the liquid level wl may be allowed to continue to decrease until completion of the
process. In this scenario, during this final portion, the time is never reset as it
is in process loop 1970 to 1968. If the liquid level drops below the lower threshold
level and fill is activated, the time simply continues counting towards the 60 second
limit, at which point the process is ended as described previously.
[0289] During the fill process in which the pre-wash mixture is provided to the sump 1858,
the fabric softener may be dispensed at a constant or varying rate such that when
the amount of liquid remaining in the sump 1858 during recirculation satisfies the
time threshold for the amount of time the liquid level remains above the lower threshold,
the concentration of fabric softener on the laundry item and the level of coverage
satisfies a predetermined threshold.
[0290] Referring again to Figure 30, supplying the pre-wash mixture may include recirculating
the pre-wash mixture onto the laundry while the drum 1860 is rotating such that minimal
mechanical energy is provided to the individual items in the laundry load. This may
include rotating the drum 1860 such that there is little relative movement of the
laundry items relative to one another, such as at low speeds or at high spin speeds
after the laundry items have already satellized to the periphery of the drum 1860.
Low speeds may be speeds at which no tumbling or rolling of the laundry items occur,
for example. In addition, supplying the pre-wash mixture may be done without activating
a clothes mover, such as an agitator or impeller.
[0291] In a variation, supplying the pre-wash mixture at 1908 of the cycle 1900 may include
rotating the drum 1860 at a first, slower rotational speed and a second, faster rotational
speed while spraying the pre-wash mixture into the treating chamber 1862 rather than
while rotating at a single speed as described with respect to the method 1950 of Figure
31. For example, the pre-wash mixture may be recirculated and sprayed into the treating
chamber 1862 while the drum 1860 is rotating up to and/or at a first, slower speed.
After a predetermined period of time or after a predetermined speed threshold is satisfied,
the recirculation and spraying of the pre-wash mixture may be stopped and the drum
rotational speed may be accelerated to a second, faster speed. When the drum rotational
speed reaches the second speed or a predetermined period of time after the drum speed
reaches the second speed, the recirculation and spraying of the pre-wash mixture may
be re-started. The second speed may be a spin speed at which a centrifugal force of
at least 1 G is provided to the laundry items such that laundry items have satellized
around the periphery of the drum 1860. Once the laundry items have satellized, even
though the drum 1860 may be rotating at a high speed, the laundry items are not moving
relative to each other.
[0292] In this manner, the pre-wash mixture may be supplied to the laundry load when there
is minimal relative movement between the items of the laundry load and not supplied
to the laundry items when the load items are moving, such as when transitioning between
the first and second speeds. This may decrease the amount of dye transfer between
laundry items due to frictional contact between laundry items as they move relative
to each other. In addition, the redistribution of the laundry load between the first
speed and the second speed may facilitate even coverage of the laundry load with the
pre-wash mixture by exposing different surfaces to the pre-wash mixture spray and/or
facilitating movement of the pre-wash mixture through the laundry load.
[0293] In yet another variation, supplying the pre-wash mixture at 1908 may be done while
the drum 1860 is rotated at different speeds so as to form multiple flow channels
through the laundry in a manner similar to that described above with respect to Figures
6A-6C. In this example, recirculation of the pre-wash mixture stops when the drum
speed is accelerated or decelerated between different speeds and is re-started once
the drum speed reaches the new speed.
[0294] The pre-wash mixture may be sprayed onto the laundry using one or more sprayers and
may be applied as a mist, fog, or stream using any suitable spray nozzle or other
spraying device or according to any methods for supplying a treating chemistry described
herein. A single sprayer 1874 may be used to spray the pre-wash mixture onto a predetermined
portion of the load that enters a spray zone corresponding to that sprayer. The spray
zone may be considered the area which liquid emitted from the sprayer directly contacts.
The sprayer 1874 may be configured to cover only a portion of the treating chamber
1682 and the laundry may be rotated to enter the portion of the treating chamber 1862
covered by the sprayer 1874. In another example, the sprayer may be configured to
cover the entire treating chamber 1862 such that all of the exposed surfaces of the
laundry in the treating chamber 1862 are covered by the liquid emitted by the sprayer
1874 without rotating the drum 1860. In yet another example, the clothes washer 1850
may include multiple sprayers to cover multiple portions of the treating chamber 1862
with a single spray.
[0295] Optionally, supplying the pre-wash mixture at 1908 of the cycle 1900 may also include
applying heat to the laundry. In one example heated air may be applied to the laundry
after it has been treated with the pre-wash mixture using the heating system 1898.
The application of heated air may be used to increase the temperature of the laundry
to a predetermined temperature, which is preferably below the setting temperature
of blood to avoid setting blood stains in the laundry items. The heated air may be
supplied to the treating chamber 1862 with or without agitation or movement of the
laundry, such as by rotation of the drum 1860. In one example, the application of
heated air to laundry that has been treated according the cycle 1900 with a pre-wash
mixture that includes a fabric softener has been found to further facilitate the inhibition
of dye transfer in the subsequent wash phase 1910 compared to when heated air is not
applied.
[0296] A benefit of the pre-wash process 1904 for forming and supplying a pre-wash mixture
is that a treating chemistry, such as a fabric softener may be uniformly applied to
a laundry load without immersing or submerging the laundry in liquid as is typically
done in a deep-fill process, which results in a substantial reduction of water consumed
during the cycle. A deep-fill process will use approximately 16 liters of water for
a 4 kg (8 lb) load, whereas the current process uses 8 liters of water for the same
load size. For example, typically during a rinse phase in which it is desired to treat
the laundry with a fabric softener, water and fabric softener will be supplied to
the treating chamber to submerge the laundry in the water and fabric softener in order
to achieve even distribution of the fabric softener.
[0297] The pre-wash process 1904 described herein may be used not only in a pre-wash setting,
but also in the traditional application of fabric softener during a rinse phase, which
follows a wash phase. The use of the current method in the traditional rinse phase
will have the same benefits of uniformly distributing a fabric softener to the laundry,
without the extra consumption of water and time of a traditional deep-fill process.
Further the use of the current method for a fabric softener dispensing during the
rinse phase can simplify the controls or user interface for the washing machine. Contemporary
washing machines have a dedicated selector to indicate that fabric softener is being
used so that the cycle of operation may be modified accordingly to include a deep-fill
rinse for application of the fabric softener. The current method can be implemented
automatically without the need for a dedicated selector.
[0298] Still referring to Figure 30, the transition between the pre-wash phase 1904 and
the wash phase 1910 of the cycle 1900 may optionally including an extraction phase
in which the laundry is spun at high speeds to extract liquid from the laundry and/or
a drain phase in which liquid collected in the sump 1858 is drained by the pump 1876.
The drain and/or extract phases may be configured so as to provide a predetermined
amount of carry-over of the pre-wash mixture into the wash phase 1910. In one example,
the laundry may be spun at high speeds to extract the pre-wash mixture from the laundry
such that a predetermined amount of the pre-wash mixture remains in the laundry. Depending
on the components of the pre-wash mixture, it may be desirable to have a small amount
of carry-over in the laundry, such as when the color care agent is a dye fixative;
in another example, in the case of a dye absorber, a higher amount of carry-over of
the pre-wash mixture may be desirable. In another example, the drain and extract phases
may be controlled such that some amount of the pre-wash mixture is extracted from
the laundry and held over in the sump 1858 such that the pre-wash mixture may be re-applied
in the subsequent wash phase 1910. This may be desirable when the pre-wash mixture
includes a dye absorber such that dye absorber is re-supplied to the laundry, such
as during a portion of the wash phase 1910 in which mechanical energy is applied to
the laundry, for example, to further facilitate inhibition of a dye transfer event.
[0299] Referring now to Figure 34, a schematic of a horizontal axis clothes washer 2050
that is similar to the clothes washer 450 of Figure 10 is illustrated except that
the clothes washer 2050 is illustrated as having an optional heating system 2098,
in a manner similar to that described above for the clothes washer 1850 of Figure
29. The elements in the clothes washer 2050 that are similar to those of clothes washer
450 have been labeled with the prefix 2000. Only those elements necessary for a complete
understanding of the embodiments of the invention are illustrated and it will be understood
that the clothes washer 2050 may include additional elements traditionally found in
a clothes washer without deviating from the scope of the invention. The clothes washer
2050 may be used to implement the cycle 1900 of Figure 30 in a manner similar to that
described above with respect to the vertical axis clothes washer 1850 of Figure 29.
[0300] Figure 35 illustrates a method 2100 for supplying a treating chemistry which may
be used at 1908 of the cycle 1900 of Figure 30 for supplying a pre-wash mixture to
the laundry in the treating chamber 2062 of the clothes washer 2050. The pre-wash
mixture may be formed according to any of the methods described above at 1906 of the
cycle 1900 to provide a predetermined amount of fabric softener, or other treating
chemistry, to the laundry in the treating chamber 2062. While the method 2100 is described
in the context of supplying a pre-wash mixture, it will be understood that the method
2100 may be used to supply any suitable treating chemistry to the laundry. The method
2100 may be used with the cycle 1900 or any other cycle in which a treating chemistry
is supplied to the laundry. The method 2100 may be implemented to provide an even
distribution of the fabric softener, or other treating chemistry, to the laundry items
under liquid volume and time constraints.
[0301] Still referring to Figure 35, the method 2100 may begin with rotating the drum 2060
to a first satellizing speed at 2102 without wetting the laundry to form an annulus
of laundry in the drum 2060. While it is contemplated that the laundry placed in the
treating chamber 2062 will be dry, there is the possibility that it may be wet when
placed into the treating chamber 2062. The lack of wetting during the formation of
the annulus 2102 means that liquid is not applied to the laundry during the formation
of the annulus, not that the laundry may not already be wet for other reasons. Rotating
the drum 2060 to the first satellizing speed without wetting the laundry may facilitate
forming a balanced load distribution that stays balanced throughout the method 2100.
The annulus will be formed as the laundry items move to the periphery of the drum
2060 due to centrifugal forces that the load experiences when rotating at a speed
at which the centrifugal force is generally greater than one gravitational force or
1 G. At 2104, the laundry may be wet by spraying a treating chemistry, such as the
pre-wash mixture, through the sprayer 2074 into the treating chamber 2062 while the
drum 2060 is still rotating at the first satellizing speed. While rotating at the
first satellizing speed, the laundry items are not moving relative to one another
and essentially remain plastered against the inner wall of the drum 2060, forming
the annulus. In this manner, the fabric surfaces forming the inner surface of the
annulus are exposed to the pre-wash mixture that is sprayed from the sprayer 2074.
[0302] The first satellizing speed may be a speed at which the laundry annulus may be formed
but which provides a first centrifugal force that is insufficient to extract liquid
carried by the laundry from the laundry at a rate that is great enough to satisfy
the pump 2076. As used herein, satisfying the pump refers to providing an amount of
liquid and a rate of liquid flow to the pump 2076 such that starvation of the pump
2076 in which the pump 2076 draws in air satisfies a predetermined threshold. The
satisfying of the pump 2076 may be done by monitoring the current draw of the pump
2076, the noise of the pump 2076, or the speed of the pump 2076. However, a convenient
way to determine that the pump 2076 is satisfied is to maintain a predetermined amount
of water in the sump 2058 or to maintain a minimum level of water in the sump 2058.
Thus, the term "satisfies" the pump is used herein to mean that the variation satisfies
a predetermined threshold, such as being equal to, less than, or greater than the
threshold value, which in this case may correspond to an amount or rate of starvation.
It will be understood that such a determination may easily be altered to be satisfied
by a positive/negative comparison or a true/false comparison. For example, a less
than threshold value can easily be satisfied by applying a greater than test when
the data is numerically inverted.
[0303] When it is determined that the pump 2076 is not satisfied, the drum speed rotation
may be decreased, by braking and/or controlling the motor 2066 to reduce the speed
and allowing the drum 2060 to slow, to a redistribution speed at 2106 without stopping
the rotation of the drum 2060. The redistribution speed may correspond to a speed
wherein the annulus of laundry which has been partially wet at 2104 redistributes
and the pump 2076 is satisfied. Redistribution of the load may include tumbling, rolling
and/or sliding all or a portion of the load. In most cases, the speed of the drum
2060 need only drop enough such that at least part, but preferably all, of the articles
forming the laundry experience a centrifugal force of less than 1G, which will permit
the articles to redistribute. While the drum 2060 may be stopped and/or reversed to
accomplish the redistribution, it is not necessary to do so. From an overall cycle
time perspective, not stopping the drum 2060 is preferred.
[0304] At a predetermined period of time following rotation of the drum 2060 at the redistribution
speed, at 2108 the drum 2060 may be accelerated to a second satellizing speed, greater
than the first satellizing speed. The second satellizing speed may correspond to a
speed at which a second centrifugal force is applied to the laundry that is sufficient
to extract liquid carried by the laundry in an amount and rate sufficient to satisfy
the pump 2076. During rotation of the drum 2060, liquid extracted from the load is
recirculated onto the load by the pump 2076 to further wet the load at 2110.
[0305] In one example, rotating the drum 2060 at the second satellizing speed and recirculating
the liquid at 2110 may be implemented for a predetermined period of time. Toward the
end of the predetermined period of time, the rotational speed of the drum 2060 may
be decreased until the pump 2076 is no longer capable of providing liquid at a sufficient
amount and pressure to the sprayer 2074 for spraying through the sprayer 2074 or until
the rotational speed of the drum 2060 reaches a speed where the centrifugal forces
are no longer sufficient to extract liquid from the laundry in an amount and rate
that is sufficient to satisfy the pump 2074. Alternatively, the drum speed may be
decreased until a predetermined drum speed is reached, until a predetermined time
period has lapsed, or until a liquid level in the sump 2058 satisfies a predetermined
liquid level threshold. In this manner the amount of liquid applied to the laundry
may be increased and the amount of liquid remaining in the sump 2058 decreases.
[0306] In an exemplary embodiment, the first centrifugal force corresponds to a 23 inch
(58.4 cm) diameter drum rotating at a first satellizing speed of 250 rpm, and the
second centrifugal force corresponds to a 23 inch diameter drum rotating at a second
satellizing speed of 350 rpm.
[0307] The amount of liquid supplied to the treating chamber 2062 for recirculation may
be limited based on the amount of laundry in the treating chamber 2062. In one example,
a maximum amount of liquid supplied to the treating chamber 2062 for a 2 kg (4 pound)
or less laundry load is 6.6 l (1.75 gallons), 8.6 l (2.27) gallons for a load amount
of 4 kg (8 pounds) or less, but greater than 2 kg (4 pounds), or 12 l (2.9 gallons)
for a load amount of 6 kg (12 pounds) or less, but greater than 4 kg (8 pounds).
[0308] As described above for the pre-wash phase 1904 of cycle 1900 with respect to Figure
30, the recirculating pre-wash mixture may be sprayed onto the laundry using one or
more sprayers. A single sprayer 2074 may be used to spray the pre-wash mixture onto
a predetermined portion of the load that enters a spray zone corresponding to that
sprayer. The spray zone may be considered the area which liquid emitted from the sprayer
2074 directly contacts. The sprayer 2074 may be configured to cover only a portion
of the treating chamber 2062 and the laundry may be rotated to enter the portion of
the treating chamber 2062 covered by the sprayer 2074. In another example, the sprayer
2074 may be configured to cover the entire treating chamber 2062 such that all of
the exposed surfaces of the laundry in the treating chamber 2062 are covered by the
liquid emitted by sprayer 2074 without rotating the drum 2060. In yet another example,
the clothes washer 2050 may include multiple sprayers to cover multiple portions of
the treating chamber 2062 with a single spray.
[0309] Optionally, supplying the pre-wash mixture at 1908 of the cycle 1900 according to
the method 2100 of Figure 35 may also include applying heat to the laundry. In one
example heated air may be applied to the laundry after it has been treated with the
pre-wash mixture using the heating system 2098. The application of heated air may
be used to increase the temperature of the laundry to a predetermined temperature,
which is preferably below the setting temperature of blood to avoid setting blood
stains in the laundry items. The heated air may be supplied to the treating chamber
2062 with or without agitation or movement of the laundry, such as by rotation of
the drum 2054.
[0310] Figure 36 illustrates a laundry treating appliance in the form of a vertical axis
clothes washer 2150 which may be used to implement a cycle of operation. The clothes
washer 2150 is similar to the clothes washer 50 of Figure 2A except for the details
of the dispensing and liquid supply systems. Therefore, elements of the clothes washer
2150 similar to that of clothes washer 50 have been numbered with the prefix 2100.
[0311] The clothes washer 2150 includes a liquid supply system for supplying water to the
clothes washer 2150 for use in the treatment of laundry during a cycle of operation.
The liquid supply system may include a source of water, such as the household water
supply 2172, which may include separate valves (not shown) for controlling the flow
of hot and cold water, respectively. Water may be supplied through an inlet conduit
2200 directly to the drum 2160 by controlling a diverter valve 2202. The diverter
valve 2202 may be a diverter valve having two outlets such that the diverter valve
2202 may selectively direct a flow of liquid to one or both of two flow paths. Water
from the household water supply 2172 may flow through the inlet conduit 2200 to the
diverter valve 2202 which may direct the flow of liquid to an outlet conduit 2204
which may be provided with a spray nozzle 2206 configured to spray the flow of liquid
into the drum 2160. In this manner, water from the household water supply 2172 may
be supplied directly to the drum 2160.
[0312] The clothes washer 2150 may also be provided with a dispensing system for dispensing
treating chemistry to the drum 2160, either directly or mixed with water from the
liquid supply system, for use in treating the laundry according to a cycle of operation.
The dispensing system may include a dispenser 2208 which may be a single use dispenser,
a bulk dispenser or a combination of a single use and bulk dispenser. Non-limiting
examples of suitable dispensers include those disclosed above with respect to the
clothes washer 50.
[0313] Regardless of the type of dispenser used, the dispenser 2208 may be configured to
dispense a treating chemistry directly to the drum 2160 or mixed with water from the
liquid supply system through a dispensing outlet conduit 2210. The dispensing outlet
conduit 2210 may include a dispensing nozzle 2212 configured to dispense the treating
chemistry into the drum 2160 in a desired pattern and under a desired amount of pressure.
For example, the dispensing nozzle 2212 may be configured to dispense a flow or stream
of treating chemistry into the drum 2160 by gravity, i.e. a non-pressurized stream.
Water may be supplied to the dispenser 2208 from the inlet conduit 2200 by directing
the diverter valve 2202 to direct the flow of water to a dispensing supply conduit
2214.
[0314] The clothes washer 2150 may also include a recirculation and drain system for recirculating
liquid within the laundry holding system and draining liquid from the clothes washer
2150. Liquid supplied to the drum 2160 through outlet conduit 2204 and/or the dispensing
supply conduit 2210 may flow by gravity to the sump 2158 through perforations 2216
provided in the side wall and bottom wall of the drum 2160. The sump 2158 may also
be formed by a sump conduit 2218 that may fluidly couple the sump 2158 to the pump
2176. The pump 2176 may direct liquid to the drain conduit 2178, which may drain the
liquid from the clothes washer 2150, or to a recirculation conduit 2180, which may
terminate at a recirculation inlet 2220. The recirculation inlet 2220 may direct the
liquid from the recirculation conduit 2180 into the drum 2160. The recirculation inlet
2220 may introduce the liquid into the drum 2160 in any suitable manner, such as by
spraying, dripping, or providing a steady flow of liquid. In this manner, liquid provided
to the tub 2154, with or without treating chemistry, may be recirculated into the
treating chamber 2162 for treating the laundry within.
[0315] The liquid supply, dispensing, and recirculation and drain systems may differ from
the configuration shown in Figure 36, such as by inclusion of other valves, conduits,
treating chemistry dispensers, sensors, such as water level sensors and temperature
sensors, and the like, to control the flow of liquid through the clothes washer 2150
and for the introduction of more than one type of treating chemistry.
[0316] The clothes washer 2150 also includes a control system for controlling the operation
of the clothes washer 2150 to implement one or more cycles of operation, similar to
the control system described above for the clothes washer 50. The control system may
include the controller 2182 and the user interface 2184 that is operably coupled with
the controller 2182.
[0317] As illustrated in Figure 37, the controller 2182 may be provided with a memory 2196
and a central processing unit (CPU) 2198. The memory 2196 may be used for storing
the control software that is executed by the CPU 2198 in implementing a cycle of operation
using the clothes washer 2150 and any additional software. Examples, without limitation,
of cycles of operation include: wash, heavy duty wash, delicate wash, quick wash,
pre-wash, refresh, rinse only, and timed wash. The memory 2196 may also be used to
store information, such as a database or table, and to store data received from one
or more components of the clothes washer 2150 that may be communicably coupled with
the controller 2182. The database or table may be used to store the various operating
parameters for the one or more cycles of operation, including factory default values
for the operating parameters and any adjustments to them by the control system or
by user input.
[0318] The controller 2182 may be operably coupled with one or more components of the clothes
washer 2150 for communicating with and controlling the operation of the component
to complete a cycle of operation. For example, the controller 2182 may be operably
coupled with the motor 2166, the pump 2176, the dispenser 2208, the clothes mover
2164 and the diverter valve 2202 to control the operation of these and other components
to implement one or more of the cycles of operation.
[0319] The controller 2182 may also be coupled with one or more sensors 2199 provided in
one or more of the systems of the clothes washer 2150 to receive input from the sensors
2199, which are known in the art and not shown for simplicity. Non-limiting examples
of 2199 that may be communicably coupled with the controller 2182 include: a treating
chamber temperature sensor, a moisture sensor, a weight sensor, a chemical sensor,
a position sensor, a liquid level sensor (e.g. a pressure sensor), and a motor torque
sensor, which may be used to determine a variety of system and laundry characteristics,
such as laundry load inertia or mass.
[0320] The previously described clothes washer 2150 may be used to implement one or more
embodiments of the invention. The embodiments of the invention seek to improve the
dispensing of the treating chemistry to more uniformly apply the treating chemistry
to the laundry. In some laundry treating appliances, such as the exemplary clothes
washer 2150 of Figure 36, the treating chemistry is dispensed directly into the drum
and will land on laundry present in the drum within the trajectory of the dispensed
treating chemistry. This can result in a non-uniform distribution of the treating
chemistry by providing regions of high treating chemistry coverage where the treating
chemistry initially comes into contact with the laundry and low levels of coverage
in regions of the laundry not initially contacted by the dispensed treating chemistry.
The embodiments of the methods described herein may be used to provide the treating
chemistry to the laundry in a manner which more uniformly applies the treating chemistry
to the laundry by dispensing the treating chemistry to the tub through the drum in
a manner which bypasses the laundry. Once in the tub, the treating chemistry may be
diluted and/or mixed with water or other liquid to form a treating chemistry mixture
during a fill phase and the treating chemistry mixture may be applied to the laundry.
[0321] Referring now to Figure 38, a flow chart of a cycle of operation 2300 for dispensing
a treating chemistry in the clothes washer 2150 is illustrated. The cycle of operation
2300 may be executed by the controller 2182 to implement the cycle of operation in
the clothes washer 2150. The cycle of operation 2300 may be used to treat the laundry
with a treating chemistry which includes at least one substance other than water during
a pre-wash phase of a cycle of operation to more uniformly distribute the treating
chemistry on the laundry. While in some instances water may be considered a treating
chemistry, in the present embodiments of the invention, uniform distribution of water
on the laundry is not a concern because the laundry will eventually all be wet with
water during subsequent fill phases and an initial, localized treatment of the laundry
with water will not negatively affect uniform wetting of the laundry during these
subsequent phases of the cycle of operation. However, some treating chemistries, other
than water, may have a tendency to concentrate at the first surface the treating chemistry
comes into contact with, limiting distribution of the treating chemistry and leading
to non-uniform distribution of the treating chemistry throughout the laundry, particularly
when the treating chemistry is a concentrated or undiluted treating chemistry. The
sequence of steps depicted for this cycle of operation and the proceeding cycles and
methods are for illustrative purposes only, and is not meant to limit any of the cycles
or methods in any way as it is understood that the steps may proceed in a different
logical order or additional or intervening steps may be included without detracting
from the invention. The cycle of operation 2300 may be implemented as a separate cycle
of operation or combined in whole or in part with any of the cycles of operations
or methods described herein, such as the wash cycle 10, for example.
[0322] Still referring to Figure 38, the cycle of operation 2300 begins with assuming that
a user has placed laundry items for treatment into the drum and selected a cycle of
operation that includes a pre-wash phase 2302 during which a treating chemistry other
than water may be dispensed followed by a wash phase 2304 during which the laundry
may be treated with a wash mixture. In an exemplary embodiment, the treating chemistry
may be a dye fixative, a dye absorber, a fabric softener or combinations thereof.
As used herein, the pre-wash phase 2302 is defined as a phase, prior to the main wash
phase, in which the laundry is treated with a treating chemistry prior to treating
the laundry with a detergent composition and mechanical action to lift soils from
the laundry. The wash phase 2304 is used to define a phase in which the laundry is
treated with a detergent composition comprising at least one treating chemistry for
providing detergency to lift soils from the laundry and mechanical action is applied
to lift soils from the laundry.
[0323] At 2306 the drum 2160 may be rotated to impart a centrifugal force to the laundry
sufficient to distribute the laundry about the periphery of the drum 2160 to form
an annulus of laundry within the treating chamber 2162. The annulus of laundry is
formed when the laundry is located adjacent the side wall of the drum 2160, exposing
the bottom wall of the drum 2160 and/or the clothes mover 2164 mounted on a rotational
axis of the drum 2160 above the bottom wall of the drum 2160. Depending on the dimensions
of the annulus and the dimensions of the clothes mover 2164, only the clothes mover
2164 may be exposed in the center of the laundry annulus or both the clothes mover
2164 and a portion of the bottom wall of the drum 2160 may be exposed in the center
of the laundry annulus.
[0324] The drum 2160 may be rotated at a speed that satillizes the majority of the laundry
to form to form the laundry annulus. Centrifugal force is proportional to the radial
distance from the rotational axis. As the annulus is formed, the laundry at an inner
surface of the annulus, closer to the rotation axis of the drum 2160, is subject to
a lower centrifugal force than the laundry at the outer surface of the annulus, adjacent
the side wall of the drum 2160. The drum 2160 may be rotated at a speed sufficient
to apply a 1G force to both the laundry near the center of the drum 2160 forming the
inner surface of the annulus and the laundry adjacent the side wall of the drum 2160
forming the outer surface of the annulus.
[0325] The treating chemistry provided in the dispenser 2208 may be supplied to the tub
2154 though the center of the laundry annulus at 2308. This may include controlling
the dispenser 2208 and/or the dispensing nozzle 2212 to supply the treating chemistry
to the drum 2160 through the center of the laundry annulus. The treating chemistry
thus supplied to the tub 2154 may be combined with water supplied to the tub 2154
at 2310, supplied either before, after, or contemporaneously with the supply of the
treating chemistry at 2308 to form a mixture of water and treating chemistry in the
tub 2154. Subsequent to the formation of the mixture of treating chemistry and water
in the tub 2154, the mixture may be supplied to the laundry at 2312. Supplying the
mixture to the laundry at 2312 may include moving the laundry through the mixture
or applying the mixture from the tub 2154 to the treating chamber 2162 through the
recirculation conduit 2180.
[0326] Figures 39 and 40 schematically illustrate the formation of the annulus and supply
of the treating chemistry at 2306 and 2310. The annulus of laundry provides a ring
of laundry 2186 located around the periphery of the drum 2160, exposing a portion
of the drum 2160 and treating chamber 2162 centered on the rotational axis of the
drum 2160. The annulus of laundry 2186 may be formed such that the laundry 2186 is
not in the direct path or trajectory of the treating chemistry supply 2314 supplied
by the dispensing nozzle 2212. In this manner, the treating chemistry supply 2314
may bypass the laundry 2186 and flow through the bottom wall of the drum 2160 to the
tub 2154 while minimizing direct contact between the treating chemistry supply 2314.
It will be understood that it is within the scope of the invention for there to be
some incidental contact between the treating chemistry supply 2314 and the laundry
2186, such as due to splashing, for example.
[0327] In the embodiment illustrated in Figure 40, the clothes mover 2164 is in the form
of an impeller having apertures 2316. The treating chemistry supply 2314 may be supplied
onto the clothes mover 2164 where the treating chemistry may flow through the apertures
2316, through apertures in the bottom wall of the drum 2160 (not shown), and into
the tub 2154. The clothes mover 2164 may include other features, such as vanes, configured
to direct treating chemistry dispensed onto the clothes mover 2164 to the tub 2154.
Alternatively, or additionally, depending on the configuration of the clothes mover
2164, the treating chemistry supply 2314 may flow to the tub 2154 directly through
the bottom wall of the drum 2160 without first flowing through a clothes mover.
[0328] Referring again to Figure 38, the wash phase 2304 may include forming a wash mixture
comprising water and at least one treating chemistry for providing detergency to lift
soils from the laundry, such as a surfactant detergent at 2318 and supplying the wash
mixture to the laundry at 2320. The detergent may be supplied to the dispenser 2208
at any point during the cycle 2300 and may include additional laundry treating chemistries,
non-limiting examples of which include surfactants, enzymes, fragrances, stiffness/sizing
agents, wrinkle releasers/reducers, softeners, antistatic or electrostatic agents,
stain repellants, water repellants, energy reduction/extraction aids, antibacterial
agents, medicinal agents, vitamins, moisturizers, shrinkage inhibitors, dye fixatives,
dye absorbers, bleaches and combinations thereof. The detergent may be supplied directly
to the drum 2160 or mixed with water from the liquid supply system. The wash mixture
may be formed by providing the detergent to the drum 2160 and/or the tub 2154 and
combining the detergent with water from the water supply system. The wash mixture
may then be supplied to the laundry at 2320 by moving the laundry through the wash
mixture and/or applying the mixture from the tub 2154 to the treating chamber 2162
through the recirculation conduit 2180.
[0329] At 2322, mechanical energy may be provided to the laundry that has been treated with
the wash mixture to lift soils from the laundry. Mechanical energy may be provided
by rotating the drum 2160 and/or actuating the clothes mover 2164. The cycle may continue
at 2324, such as with one or more rinse or extraction phases.
[0330] Referring now to Figure 41, a method 2500 for treating laundry with a treating chemistry
in a pre-wash phase is illustrated. The method 2500 may be used with the pre-wash
phase 2302 of the cycle of operation 2300 or combined in whole or in part with any
of the cycles of operations or methods described herein, such as the wash cycle 10,
for example. While the method 2500 is described in the context of a pre-wash phase
of a cycle of operation, it will be understood that the method 2500 may be used at
any point during a cycle of operation to facilitate a more uniform distribution of
a treating chemistry onto the laundry in the treating chamber2162.
[0331] The method 2500 may begin with controlling the motor 2166 to rotate the drum 2160
to satisfy a first speed threshold to form the annulus of laundry at 2504. The annulus
of laundry may be formed by rotating the drum 2160 at a speed sufficient to apply
a 1G force to both the laundry near the center of the drum 2160 forming the inner
surface of the annulus and the laundry adjacent the side wall of the drum 2160 forming
the outer surface of the annulus, which may be considered a satellizing speed. Satisfying
the first speed threshold may include rotating the drum 2160 to a predetermined speed
or rotating the drum 2160 at a predetermined speed for a predetermined period of time.
An exemplary drum rotation speed for forming the laundry annulus for a drum 2160 having
a diameter of 23 inches (58.4cm) is 765 rpm. The first speed threshold may be satisfied
by rotating the drum 2160 up to 765 rpm or rotating the drum 2160 at 765 rpm for a
predetermined period of time.
[0332] The laundry may optionally be wetted at 2502 with liquid, such as water from the
water supply system, to dampen the laundry to facilitate formation of the annulus
of the laundry. Damp laundry may form and hold the shape of the annulus better than
dry laundry by facilitating the laundry items adhering to the drum 2160 and other
laundry items and facilitating compression of the load during spinning. In one example,
an 8 pound (3.63 kg) load may be wet with about 380 mL of liquid to facilitate formation
of the annulus at 2504.
[0333] At 2506, the drum 2160 may be rotated to satisfy a second speed threshold, lower
than the first speed threshold. The second speed threshold at 2506 may be selected
to correspond to a speed that minimizes splashing of the treating chemistry dispensed
at 2508. The speed of rotation of the drum 2160 may be decreased from the speed that
satisfies the first threshold by braking the rotation of the drum 2160, controlling
the motor 2166 to rotate the drum 2160 in the opposite direction, or by allowing the
drum 2160 to coast from the speed that satisfies the first threshold down to the speed
that satisfies the second speed threshold, such as by shutting off the motor 2166,
for example. While it may be desirable to dispense the treating chemistry when the
drum 2160 is rotating slowly so as to minimize splashing of the treating chemistry,
it is also desirable to not significantly extend the cycle time. Thus the second speed
threshold at 2506 may be selected in order to balance the desire to minimize splashing
with the desire to not extend the cycle time significantly. Satisfying the second
speed threshold may include rotating the drum 2160 to a predetermined speed or rotating
the drum 2160 at a predetermined speed for a predetermined period of time. In an exemplary
embodiment, the speed satisfying the second speed threshold is 50 rpm.
[0334] The treating chemistry may be supplied to the tub 2154 at 2508 when the second speed
threshold is satisfied. As described above at 2308 in Figure 38 and with respect to
Figures 39 and 40, the treating chemistry is supplied indirectly to the tub 2154 through
the portions of the drum 2160 and/or clothes mover 2164 exposed within the laundry
annulus such that the treating chemistry bypasses the laundry.
[0335] Subsequent to or contemporaneous with the supply of treating chemistry at 2508, the
controller 2182 may control the water supply system to supply water to the tub 2154
to increase a level of liquid in the tub 2154 to satisfy a predetermined fill level
threshold at 2510. In one example, the treating chemistry is supplied to the tub 2154
in a single aliquot subsequent to or contemporaneous with supply of water at 2510.
In yet another example, the treating chemistry may be supplied incrementally to the
tub 2154 contemporaneous with the supply of water at 2510. The fill level threshold
may be a fill level that corresponds to an amount of liquid in the tub 2154 sufficient
to move the laundry through during rotation of the drum 2160 and/or movement of the
clothes mover2164 to uniformly treat the laundry to the treating chemistry. The motor
2166 may be controlled to continue to rotate the drum 2160 at the speed that satisfies
the second speed threshold or any other speed suitable for filling the tub 2154.
[0336] Optionally, at 2512, prior to the fill level satisfying the fill level threshold,
the drum 2160 may be rotated to facilitate mixing the liquid in the tub 2154. In an
exemplary embodiment, when the fill level satisfies an intermediate fill level threshold
corresponding to a fill level in which the liquid has come into contact with an underside
of the drum 2160, the drum 2160 may be rotated to stir the liquid in the tub 2154
to mix the treating chemistry and water in the tub 2154. Stirring the liquid in the
tub 2154 may facilitate dissolving the treating chemistry in the water added during
the filling and/or facilitate uniformly distributing the treating chemistry within
the water in the tub 2154. For example, the drum 2160 may be rotated at 120 rpm to
150 rpm to facilitate mixing the liquid in the tub 2154 for a predetermined period
of time, such as 4-5 seconds. Following the mixing of the liquid in the tub 2154,
the rotation speed of the drum 2160 may be controlled to decrease to a speed suitable
to continue the filling process at 2512, such as the speed that satisfies the second
speed threshold. The water supply may be controlled to stop filling during the mixing
of the liquid at 2512 and re-initiated following the mixing at 2512 to continue filling
the tub 2154 to satisfy the predetermined liquid fill level threshold at 2510.
[0337] At 2514, the laundry may be redistributed within the drum 2160 to facilitate wetting
the laundry with the treating chemistry mixture in the tub. The drum 2160 may be controlled
to rotate at different speeds and/or in alternating directions to cause the laundry
to shift or move within the drum 2160 to facilitate evenly wetting the laundry items
in the drum 2160. The redistribution process may be repeated one or more times prior
to, after, or contemporaneously with the filling process at 2510. In an exemplary
embodiment, the motor 2166 may be controlled to rotate the drum 2160 by alternately
turning the motor 2166 on and off and/or alternating the direction of rotation. Alternatively,
or in addition to, rotating the drum 2160 to redistribute the laundry, the clothes
mover 2164 may be operated to agitate the laundry with the drum 2160 to facilitate
movement of the laundry through the treating chemistry mixture in the tub 2154, which
may also be repeated one or more times prior to, after, or contemporaneously with
the filling process at 2510. In an exemplary embodiment, the clothes mover 2164 is
controlled to agitate the laundry during the fill process at 2510, either intermittently
or continuously, and continues to agitate the laundry after the liquid fill level
threshold is satisfied.
[0338] In another optional process at 2516, the drum 2160 may be rotated to facilitate wetting
the laundry items located adjacent the side wall of the drum 2160. The drum 2160 may
be rotated at a predetermined speed which facilitates movement of the treating chemistry
mixture up the side wall of the drum 2160 in a parabolic profile to wet items adjacent
the side wall of the drum 2160. An exemplary speed for forming the parabolic profile
is 40 rpm for a 23 inch (58.4 cm) diameter drum. The pre-wash method 2500 may be completed
at 2518 by implementing one or more extraction and/or drain phases before continuing
on to the main wash phase, such as the wash phase 2304 of Figure 38.
[0339] The processes 2300 and 2500 described herein provide a process to facilitate more
uniform coverage of laundry items with a treating chemistry in clothes washers in
which dispense the treating chemistry directly into the treating chamber 2162 rather
than the space 2156 between the drum 2160 and the tub 2154. Uneven coverage of laundry
items with a concentrated or undiluted treating chemistry may produce areas of high
concentration of treating chemistry on the laundry items where the treating chemistry
initially contacts the laundry which may be difficult to disperse. A traditional method
to minimize uneven treating chemistry coverage is to use large volumes of water and
treating chemistry. However, using large volumes may result in inefficient resource
usage, such as water and energy to heat the large volume of water, and may also increase
the cost to the consumer by increasing the amount of treating chemistry each cycle
consumes. The processes 2300 and 2500 described herein facilitate a more uniform coverage
of laundry items without the use of large volumes of water and treating chemistry
by controlling the dispensing of the treating chemistry to bypass the laundry in the
treating chamber 2162 and provide the treating chemistry to the tub 2154 through the
drum 2160.
[0340] To the extent not already described, the different features and structures of the
various embodiments may be used in combination with each other as desired. For example,
any of the processes 10, 100, 120, 150, 200, 206, 212, 300, 500, 550, 600, 650,700,
710, 800, 850, 1000, 1020, 1050, 1300, 1500, 1600, 1700, 1900, 1950, 2100, 2300, 2500
may be combined in whole or in part with one another and used with any of the apparatus
50, 450, 1100, 1850, 2050, or 2150 described herein or any other suitable apparatus
not explicitly described herein. That one feature may not be illustrated in all of
the embodiments is not meant to be construed that it cannot be, but is done for brevity
of description. Thus, the various features of the different embodiments may be mixed
and matched as desired to form new embodiments, whether or not the new embodiments
are expressly disclosed.
[0341] While the invention has been specifically described in connection with certain specific
embodiments thereof, it is to be understood that this is by way of illustration and
not of limitation. Reasonable variation and modification are possible to the forgoing
disclosure and drawings without departing from the scope of the invention which is
defined in the appended claims.