[0001] This invention relates to a method and apparatus for washing textile webs in open-width.
[0002] The term "washing" used herein and in the claims is to be construed as including
scouring and rinsing.
[0003] Some fabrics are susceptible to creasing and it is for this reason that they are
washed in open-width rather than being washed in rope configuration and consequently
these fabrics are not subjected to any working or milling action to increase the bulk
or body thereof. Open-width washing therefore tends to be restricted to fabrics which
do not require milling but the majority of wool fabrics which can readily be washed
in open-width do require to be milled or worked.
[0004] It is an object of the present invention to provide an open-width fabric washing
method and apparatus which provides this milling facility when required for a fabric.
[0005] According to a first aspect of the present invention there is provided a method of
washing fabric in open-width which includes the steps of reducing the fabric width
and, while in such reduced-width configuration, subjecting the fabric to a mechanical
milling action whereby the bulk of the fabric is increased.
[0006] The term "milling" used herein and in the claims is to be construed as meaning any
working action whereby adjacent contacting portions of the fabric are caused to be
moved relative to each other to stimulate increase in fabric bulk.
[0007] Preferably, the fabric is subjected, while being mechanically milled, to a strong
soaping action.
[0008] The terms "soap" and "saponaceous" used herein and in the claims are to be construed
as including synthetic or natural milling additives, for example, synthetic detergents.
[0009] The fabric may alternatively be subjected to the strong soaping action while still
in the open-width configuration and prior to mechanical milling.
[0010] Preferably, the fabric is mechanically milled in a compartment wherein it is subjected
to the action of reciprocating pushing means, which causes relative rubbing movement
between adjacent portions of fabric, the pushing means and the walls of the compartment
thereby to achieve bulking of the fabric.
[0011] The mechanical milling may alternatively be effected by other mechanical working
elements such, for example, as rollers, paddles, flails or vibratory devices.
[0012] Where rollers are employed to apply the mechanical milling action the method includes
the step of reducing the width of the fabric to form a rope configuration.
[0013] Preferably the method comprises the steps of re-opening the milled fabric to open-width
configuration and thereafter subjecting it to at least a final rinsing action, but
preferably a washing or lathering action to remove retained soap followed by a final
rinsing action.
[0014] The fabric, after being subjected to the mechanical milling action may pass through
a squeezing nip or suction means to remove saponaceous liquid therefrom.
[0015] Preferably the method includes the step of returning such liquid to the mechanical
milling compartment.
[0016] Preferably the method includes the step of controlling the rate of extraction of
the fabric from the mechanical milling stage to ensure that neither too much or too
little fabric is present in the milling compartment.
[0017] In the former condition there is risk of damage to the mechanical milling elements
and compartment and in the latter condition little or no milling of the fabric would
occur.
[0018] The mechanical milling of the reduced-width fabric may be effected in two or more
stages with possibly intervening soaping stages between adjacent mechanical milling
stages.
[0019] The washing method may be multi-stage in nature with a mechanical milling stage between
adjacent washing stages. In this instance, the fabric may be constrained to move from
open-width to reduced-width and back to open-width more than once, or may move directly,
in reduced-width configuration, from one milling stage to a following milling stage.
[0020] The open-width washing method is preferably substantially as disclosed in published
European Patent No. 0259169 with the mechanical milling stage being preferably interposed
between the first and second washing stage, or alternatively the second washing stage
and final rinsing stage, or both.
[0021] Preferably the reduced-width fabric is caused to dwell by accumulation for a predetermined
time in the mechanical milling stage to control the degree of milling to which the
fabric is subjected and the consequent increase in fabric bulk.
[0022] In the milling stage, the degree of milling to which the fabric is subjected may
alternatively or additionally be controlled by the mechanical forces to which the
fabric is subjected.
[0023] These mechanical forces may be compressive and/or kinetic in nature.
[0024] According to a second aspect of the present invention there is provided apparatus
for washing fabric in open-width which incorporates a mechanical milling apparatus
into and through which the fabric is constrained to pass and which comprises a milling
compartment of a width less than the open-width of the fabric, and kinetic means within
the milling compartment for causing relative rubbing movement between adjacent portions
of the fabric, the compartment and the kinetic means to increase the bulk of the fabric.
[0025] The kinetic milling means is preferably constituted by a reciprocable pushing member.
[0026] Preferably the kinetic milling means comprises two opposed pairs of reciprocable
pushing members or stocks defining therebetween a mechanical milling zone.
[0027] Preferably means for driving the pushing members or stocks of each pair simultaneously
in opposite directions is provided.
[0028] The driving means may be arranged to move each pair of opposed pushing members simultaneously,
in phase, in the same or opposite directions, or in any desired combination of directional
movements, in phase or out of phase.
[0029] The milling compartment preferably comprises a trough or similar having a top cover
defining in spaced relationship, a fabric inlet and a fabric outlet.
[0030] Preferably the cover is openable or removable to permit access to the milling zone
and the pushing members or stocks.
[0031] Preferably, means is provided for delivering a saponaceous solution into the milling
compartment.
[0032] Preferably, the delivery means supplies the saponaceous solution to the inlet end
of the milling compartment, preferably at or through the fabric inlet in the cover.
[0033] Preferably, a squeeze nip or suction means is provided downstream of the milling
compartment to remove saponaceous liquid from the milled fabric.
[0034] Preferably, means is provided to deliver such extracted saponaceous liquid into the
milling compartment, preferably at the fabric inlet in the cover.
[0035] Alternatively, the fabric is conveyed through a saponaceous solution bath prior to
entering the milling compartment.
[0036] The open-width washing apparatus is preferably substantially as disclosed in the
aforesaid published European Patent Application with the mechanical milling apparatus
disposed between two adjacent washing stages or a washing stage and rinsing stage.
[0037] An embodiment of the present invention will now be described, by way of example,
with reference to the accompanying drawings, in which:-
Fig. 1 is a diagrammatic side elevation of an open-width washing apparatus incorporating
a preferred form of mechanical milling apparatus according to the present invention;
and
Fig. 2 is a perspective view of the mechanical milling apparatus of Fig. 1.
[0038] In Fig. 1 there is shown an open-width continuous washing apparatus comprising three
identical stages 10, 11 and 12.
[0039] The apparatus is, for example, used for scouring and washing a continuous length
of open-width, wool fabric indicated by the reference F.
[0040] Considering the open-width washing aspect only of the apparatus the fabric F is subjected
in stage 10 to washing with a warm concentrated scouring liquor (a solution of warm
water, soap and soda ash), in stage 11 to washing employing a warm less concentrated
scouring liquor, and in stage 12 to rinsing solely with warm water.
[0041] The constructional features of stages 10, 11 and 12 are identical and therefore only
stage 10 will be described in detail.
[0042] The fabric F, in washing stage 10, is conveyed through three vertically-spaced, identical
washing levels at each of which is provided a pair of sprays 13 for impregnating or
soaking both sides of the fabric F with the scouring liquor (water in stage 12), a
bowed expander bar 14 for maintaining the fabric in open-width and a suction tube
15 for pulling liquor through and out of the fabric F.
[0043] The fabric F, during its vertical movement, is constrained by the expander bars 14
and guide rollers 16 to follow vertically-spaced inclined, generally horizontal paths,
down which the scouring liquid (or warm water) runs, the suction tubes 15 being disposed
below these paths.
[0044] The extracted scouring liquor and accompanying air is subjected to separation and
recirculation as is disclosed in the aforesaid published European Patent Application.
[0045] The configuration of the washing levels as shown and described ensures that there
is a pool or stream of washing liquor on top of the fabric F as it passes over the
bottom and the middle suction tubes 15 while the top suction tube 15 operates above
the washing liquor supply level ensuring that when the fabric F leaves the top suction
tube 15 the major proportion of dirt and other contaminants contained in the fabric
F are removed and that the warm fabric F contains a residue of concentrated scouring
liquor but with the liquor content of the fabric F being substantially reduced.
[0046] It is preferred that the retained liquor content of the fabric F be not more than
approximately 50% of the dry weight of the fabric F.
[0047] Transport rollers for use in conveying the fabric F through the washing apparatus
are indicated by the reference 17.
[0048] The continuous open-width washing apparatus as shown in Fig. 1, therefore, subjects
the fabric F to washing and scouring with an extremely concentrated liquor at stage
10, washing with less concentrated scouring liquor at stage 11 and rinsing using only
warm water at stage 12.
[0049] The present invention is concerned with adding to the open-width washing apparatus
a facility for milling the fabric F in continuous form so that it is given increased
bulk or body but without rope marking the fabric F as occurs with conventional batch
milling machinery.
[0050] It is known to those skilled in the art that milling of fabric to increase the bulk
thereof is best achieved if the fabric is not too wet, is warm, has a sufficiently
high dry soap content and is subjected to mechanical forces sufficient to disturb
the fibres of the fabric relative to each other.
[0051] The open-width fabric F leaving the top suction tube 15 of stage 10 is, as described
above, not too wet and is warm.
[0052] To ensure that the fabric F is not too wet for the milling operation, liquor extraction
is increased at the top suction tube 15 of washing stage 10 by providing two (or possibly
more) rows of suction holes compared with the customary single row of holes. This
increased liquor extraction can be achieved in any other suitable manner.
[0053] Milling of the open-width fabric F is achieved by locating between two washing stages
a milling apparatus within which the fabric F is mechanically worked to give the desired
increased body or bulk thereto.
[0054] In Fig. 1 there is shown between washing stages 10 and 11 a milling apparatus 18
in accordance with the invention.
[0055] The milling apparatus 18 comprises a trough 19 closed by a stationary fixed cover
20 which is removable or openable to permit access to the trough interior and which
is fixed in position during the milling operation.
[0056] The cover 20 defines a fabric inlet 21 adjacent one end of the trough 19 and a fabric
outlet 22 adjacent the other end.
[0057] Within the trough 19 are two opposed pairs of pushing members 23, 24 which define
between them a milling zone 25.
[0058] The pushing members 23, 24 are caused to reciprocate to-and-fro by convenient drive
means generally indicated at 26.
[0059] Each pushing member 23 and its respective opposed pushing member 24 can be reciprocated,
in phase, in the same direction or opposite directions simultaneously or the reciprocating
movements of the respective pairs 23, 24 or of all four can be out of synchronism.
[0060] The drive means 26, which may be of any convenient form, may, for example, comprise,
for each pair of pushing members 23, 24, a respective crank shaft 27 coupled to its
pushing members or stocks 23, 24 by connecting rods 28, the crank shaft 27 being drivingly
interconnected by endless transmission belts or chains 29 driven, in turn, by a motor
30. Each pair of pushing members 23, 24 may alternatively have an independent drive
to give phased or out-of-phase reciprocation as aforesaid.
[0061] A saponaceous liquid supply tank 31 (see Fig. 2) is disposed adjacent to the milling
apparatus 18, which tank 31 incorporates a heater, and the saponaceous liquid (a soap
and warm water solution) is delivered into the trough 19 by a supply pipe 32.
[0062] The saponaceous liquid is suitably pumped (see 31A) along the supply pipe 32 which
delivers same out of bottom holes or apertures into the trough 19
via the fabric inlet 21, the pipe 32 returning to the supply tank 31 as shown (a simple
ring circuit).
[0063] The saponaceous liquid is a strong soap solution and is supplied in such quantity
that, unlike existing milling practice as hereinbefore mentioned, the fabric F in
the milling zone 25 is thoroughly saturated with the saponaceous liquid so that has
a substantially sloppy character or feel.
[0064] It is to be clearly understood, however, that the conventional "dry soap" method
hereinbefore mentioned may alternatively be employed.
[0065] The strong soap referred to herein and in the claims for milling purposes may, for
example, contain 2% to 20% dry weight of soap. A convenient range is considered to
be between 6% and 10%.
[0066] The soaping of the fabric F leaving washing stage 10 for milling may alternatively
be effected by passing the washed fabric through a soaping bath disposed between the
washing stage 10 and the milling apparatus 18 and preferably between washing stage
10 and a width-reducing device 34 hereinafter described.
[0067] The width of the trough 19 is less than the fully open-width of the fabric F, say
40% of said fully open-width and therefore the width of the fabric F leaving the washing
stage 10 requires, in accordance with this invention, to be restricted.
[0068] A fabric width restricting device 34 (see Fig. 2) is, therefore, provided between
the washing stage 10 and the milling apparatus 18.
[0069] In this embodiment, the width restricting device 34 comprises a triangular frame,
whereof the sides 34A are adjustable relative to the base 34B to vary the size of
the enclosed triangular area and consequently the restricted width of the fabric F.
[0070] Other forms of width restricting device may be employed. For example, a ring or tube
through which the fabric F passes, or a downwardly converging chute with containing
side walls.
[0071] An expander bar or bars 35 together with opening guiders is provided between the
milling apparatus 18 and the washing stage 11 to assist the fabric F in opening to
its full width again after leaving the milling apparatus.
[0072] A driven squeezing nip 36, or suction means (not shown), may be provided upstream
or downstream of the expander bar 35 to remove saponaceous liquid from the milled
fabric F and such extracted liquid is returned into the milling apparatus 18 through
the fabric inlet 21 by a pipe or duct 37 connected to a collection tray 37A or by
any other convenient return device.
[0073] The driven nip 36, if provided, assists in pulling the milled fabric F out of the
milling apparatus.
[0074] Alternatively the extracted saponaceous liquid may be returned to the supply tank
31.
[0075] The fabric F is thus washed and scoured in washing stage 10 in fully open-width form,
is delivered, not too wet, in reduced width form into the milling apparatus 18 where
it is soaked with warm saponaceous liquid and subjected to the milling or working
action of the reciprocating pushing members or stocks 23, 24 within the working zone
25, exits from the milling apparatus 18, possibly passing through the squeezing nip
36, to take up its full open-width configuration again before passing into washing
stage 11, which may use simply warm water or warm less concentrated scouring liquor.
[0076] As a result of this invention fabrics which are normally run on batch machines in
rope form to achieve a milling action with the risk of rope marks can be washed on
a continuous machine in open-width, milled in reduced width where creasing not rope
marking will occur, and then opened again to full width for further washing with consequent
removal of any creasing, or substantially so.
[0077] The reduced width fabric may be milled or worked within a milling compartment such,
for example, as 18 by other than reciprocating pushing members or stocks 23, 24. The
milling members may, for example, be rollers, paddles, flails or vibratory devices.
[0078] If rollers are employed the fabric F will be reduced in width to a rope configuration.
[0079] It is desirable that the milling zone 25 contains at any one time neither too much
or too little fabric possibly resulting in damage to the milling apparatus 18 or little
or no milling action on the fabric, and consequently a sensing device may be associated
with the driving motor or motors of the milling apparatus to measure the power output
which will indicate the fabric content of the milling zone 25, which sensing device
is also coupled to the drive for the transport rollers 17 of the washing stage 11
and the drive for the squeezing nip 36, if provided, to control the rate of removal
of the fabric F from the milling zone.
[0080] Other sensing arrangements may be employed to detect the fabric content of the milling
zone 25 and control the rate of extraction of the fabric F from the milling zone.
[0081] The degree of milling is controlled by fabric dwell time within the milling zone
25 and the reciprocable speed of the oppositely-acting pushing members 23, 24, and
the quantity of fabric in the milling zone 25 which varies the pressure on pushing
members 23, 24.
[0082] The milled fabric, now once again in open-width, passes into the washing stage 11
for lathering clean prior to its passage to rinsing stage 12.
[0083] To correct and remove marking of the fabric which may occur during milling, the fabric
may be passed into a second milling stage before being passed in open-width to the
washing (lathering) stage 11 with or without intervening widthwise opening of the
fabric.
[0084] For the avoidance of doubt the present invention may be applied to open-width washing
apparatus other than that described herein.
1. A method of washing fabric continuously in open-width which includes the steps of
reducing the fabric width and, while in such reduced width configuration, subjecting
the fabric to a mechanical milling action whereby the bulk of the fabric is increased.
2. A method as claimed in claim 1 comprising the step of washing the fabric in open-width
prior and subsequent to subjecting it to the reduced width mechanical milling action.
3. A method as claimed in claim 1 or 2 comprising the step of subjecting the reduced
width fabric, while being mechanically milled, to the action of a strong soaping solution,
or the step of subjecting the fabric, while in open-width configuration and prior
to width reduction and milling, to the action of strong soaping solution.
4. A method as claimed in any one of claims 1 to 3 in which the fabric is mechanically
milled in a compartment wherein it is subjected to the action kinetic milling means,
for example, reciprocating pushing means, which causes relative rubbing movement between
adjacent portions of fabric, the kinetic milling means and the walls of the compartment
thereby to achieve bulking of the fabric.
5. A method as claimed in claim 3 or 4 comprising the step of removing soap solution
(saponaceous liquid) out of the milled fabric as it returns to, or has returned to,
full open-width either by a squeezing action or a suction action.
6. Apparatus for continuously washing fabric in open-width which incorporates a mechanical
milling apparatus into and through which the fabric is constrained to pass and which
comprises a milling compartment of a width less than the open-width of the fabric,
and kinetic means within the milling compartment for causing relative rubbing movement
between adjacent portions of the fabric, the compartment and the kinetic means to
increase the bulk of the fabric.
7. Apparatus as claimed in claim 6 in which the kinetic milling means comprises two opposed
pairs of reciprocable pushing members or stocks defining therebetween a mechanical
milling zone.
8. Apparatus as claimed in claim 6 or 7 in which means is provided for delivering a saponaceous
solution into the milling compartment, preferably at a fabric inlet to the milling
compartment.
9. Apparatus as claimed in any one of claims 6 to 8 comprising, upstream of the mechanical
milling apparatus in terms of the direction of fabric movement a device for reducing
the width of the washed fabric prior to its entry into the mechanical milling apparatus.
10. Apparatus as claimed in claim 8 or 9 in which a squeeze nip or suction means is provided
downstream of the milling compartment to remove saponaceous liquid from the milled
fabric.