FIELD OF THE INVENTION
[0001] The present invention relates to toilet seat covers emplaced over a toilet seat to
insulate the user therefrom.
BACKGROUND OF THE INVENTION
[0002] Toilet seat covers are well known in the art. Toilet seat covers are typically used
in a public restroom where the user say be concerned about the sanitary conditions
and how such conditions may affect his or her hygiene. When using a public toilet
seat which may appear to be unsanitary or which is actually unclean, the user typically
places the toilet seat cover over the toilet seat. The user then sits on the toilet
seat cover, so that it is interposed between the skin of the user and the toilet seat
itself. The user then feels insulated from any unsanitary conditions which may be
present on the toilet seat - either due to misuse by the previous user or due to inadequate
cleaning of the public restroom.
[0003] However, toilet seat covers according to the prior art frequently suffer from a serious
drawback - they do not remain in place on the toilet seat during and throughout the
entire time period of their use. The toilet seat cover must remain in the desired
position from the time it is emplaced on the toilet seat by the user, until the user
is finished using the toilet.
[0004] This entire time can be broken down into two consecutive time periods: a first time
period starting when the user emplaces the toilet seat cover in the desired position
on the toilet seat and ending when the user sits on the toilet seat cover; and a second
time period beginning when the user sits on the toilet seat cover and ending when
the user rises from the toilet seat.
[0005] Unfortunately, the toilet seat cover can move out of the desired position during
either of the two consecutive time periods. Upon moving out of the desired position,
the toilet seat cover will actually or apparently fail to protect the user from real
or perceived unsanitary conditions on the toilet seat. In either situation, the toilet
seat cover has failed to perform the desired function.
[0006] During the first time period, the toilet seat cover may not remain in and move from
the desired position due to slight breezes present in the restroom. Even the slight
windage caused by the user sitting down onto the toilet seat cover may cause it to
move from the desired position. In extreme cases, the toilet seat cover may even fall
off the toilet seat.
[0007] Toilet seat covers constructed according to the prior art exacerbate this problem.
Such toilet seat covers are typically constructed of a single region, uniform high
density, uniform low basis weight paper. This construction is typical because such
paper is less costly to produce than lower density paper or paper having multiple
regions comprising different densities or basis weights.
[0008] However, such high density paper can be relatively stiff and overhang the edge of
the toilet seat without conforming to the shape of the edge of the toilet seat. Instead,
such a toilet seat cover projects over the edge of the toilet seat without draping.
[0009] The packaging of toilet seat covers according to the prior art further exacerbates
this problem. Packaged toilet seat covers are creased with sharp fold lines - in order
to be packed as tightly as possible into a compact kit for the convenience of the
user. High density toilet seat covers have a particular proclivity to form sharp fold
lines at the creases. The sharp fold lines at the creases allow the toilet seat cover
to be more tightly packaged in a smaller space, minimizing the package size. However,
the sharp fold lines structurally reinforce the toilet seat cover, increasing its
stiffness by increasing its section modulus.
[0010] By increasing the stiffness of the toilet seat cover (regardless of its material)
through such structural reinforcement, the tendency of the toilet seat cover to conform
to the shape of the toilet seat at the edges is minimized. By stiffening the toilet
seat cover through structural reinforcement, it conforms to the shape of the toilet
seat to a lesser degree. The less the toilet seat cover conforms to the toilet seat,
the smaller the area in contact with the toilet seat will be and the more likely the
toilet seat cover is to move out of the desired position during the first time period.
[0011] Several attempts have been made in the art to overcome this problem. For example,
one teaching in the prior art shows the inner periphery of the toilet seat cover slitted
to provide depending tongues. The user emplaces the toilet seat cover on the toilet
seat, then manually depresses the tongues into position. The depending tongues grip
the inside of the toilet seat, assisting the toilet seat cover in remaining in the
desired position.
[0012] This arrangement suffers from several obvious drawbacks. First, the user must spend
more time in a public restroom (which the user generally considers to be unsanitary
in the first place) in order to deploy the depending tongues. Secondly, the user must
manually place the tongues in position so that they grip the inside of the toilet
seat. This action requires the user to handle the toilet seat cover in position while
it is on the very toilet seat the user does not wish to touch.
[0013] One attempt to overcome at least some of these disadvantages is to provide a toilet
seat cover having a mitten made from the excess material in the center of the toilet
seat cover. This toilet seat cover further comprises separable top and bottom sheets.
The user wears the mitten to emplace the toilet seat cover in position such that the
bottom sheet is beneath the toilet seat, i.e. between the toilet seat and the toilet
itself. The top sheet is then placed in position on top of the toilet seat.
[0014] This arrangement suffers from much of the same drawbacks as the embodiment earlier
described. For example, in this second arrangement, the user must spend considerable,
extra and superfluous time in the public restroom placing the toilet seat cover in
position and, even though wearing a mitten, is committed to additional handling of
the very same toilet seat the user wishes not to touch.
[0015] Yet another attempt in the prior art disposes double sided adhesive on the bottom
of the toilet seat cover. The toilet seat cover is placed in the desired position
on the toilet seat and retained thereon by the adhesive. This arrangement suffers
from yet other drawbacks. First, the double sided adhesive increases the cost of the
toilet seat cover. Double sided adhesive requires additional materials (with concomitant
costs and disposal problems) to be utilized in packaging. Particularly, each piece
of the adhesive must be covered by its own release paper. Of course, the user must
spend additional time in the public restroom removing the release paper before he
or she can begin to emplace the toilet seat cover in the desired position on the toilet
seat.
[0016] Yet another drawback with this arrangement occurs if the user does not properly position
the toilet seat cover the first time. The user must carefully remove the toilet seat
cover without ripping it, then reposition it - hoping the adhesive still has enough
adhesion to hold the toilet seat cover in the desired position.
[0017] Still further drawbacks occur when the user wishes to flush away the used toilet
seat cover. The user encounters more handling of an adhered toilet seat cover than
one which is not adhered, in order to remove it from the toilet seat and flush it
away.
[0018] Examples of such prior art toilet seat covers include U.S. Patent 1,064,274 issued
June 10, 1913 to Young; U.S. Patent 4,875,242 issued October 24, 1989 to Albrecht
et al.; U.S. Patent 4,887,321 issued December 19, 1989 to MacLean; and U.S. Patent
5,144,698 issued September 8, 1992 to McKenzie.
[0019] During the second time period, the toilet seat cover may stick to the skin of the
user. Such sticking often occurs because the user perspires onto the toilet seat cover.
The surface tension of the perspiration may cause the adhesion between the toilet
seat cover and the skin to become greater than the gravitational force drawing the
toilet seat cover towards the toilet seat. When this imbalance of forces occurs, any
slight movement by the user will cause the toilet seat cover either to rip or to move
from the desired position. Either occurrence may directly expose the user to the toilet
seat.
[0020] The high density, low basis weight toilet seat covers according to the prior art
often exacerbate this problem too. The absorptive capacity of high density, low basis
weight toilet seat covers is typically so small and the hydrophobicity so great, that
perspiration occurring at one location on the toilet seat cover is not readily transmitted
to other portions of the toilet seat cover. Localizing the perspiration, or simply
exceeding the absorptive capacity of the toilet seat cover, often causes the toilet
seat cover to stick to the user at the localized sites of perspiration. Such sticking
is believed to be caused by the interface of water between the skin of the user and
the toilet seat cover. Under extreme conditions, the toilet seat cover may stick to
the toilet seat instead of, or in addition to, sticking to the user.
[0021] Yet other toilet seat covers in the art provide a top layer of porous paper, coated
on the bottom side with water repellent plastic or wax. Such toilet seat covers may
not be readily flushable due to the water repellent material and require a more expensive
construction than single lamina toilet seat covers. Furthermore, any adhesive used
to join the two laminae will stiffen the toilet seat cover and limit the utilization
of the full absorbent capacity of the first layer. Examples of such toilet seat covers
are found in the aforementioned U.S. patent 4,875,242 issued October 24, 1989, to
Albrecht et al. and U.S. Patent 4,887,321 issued December 19, 1989, to MacLean.
[0022] WO-A-887832 discloses toilet seat covers made of synthetic or natural rubber material
and presents the features of the preamble of claim 1.
[0023] It is clear from the foregoing that departure is needed from the prior art. What
is needed is a toilet seat cover which remains in the desired position without requiring
additional steps by the user to do so during the first time period and which also
remains in the desired position while in use during the second time period. Accordingly,
it is an object of this invention to provide a toilet seat cover which resists ordinary
displacing forces between the time the user emplaces it on the toilet seat and the
time the user sits on the toilet seat cover, yet does not require additional manipulative
steps by the user or increase the user's time in the restroom. Furthermore, it is
an object of this invention to provide a toilet seat cover which resists movement
caused by sticking to the skin of the user while the toilet seat cover is in use.
[0024] The toilet seat cover of the invention is defined by the features of claim 1.
BRIEF SUMMARY OF THE INVENTION
[0025] The present invention comprises a toilet seat cover for insulating a user from a
toilet seat. The toilet seat cover is drapable and conforms to the shape of a toilet
seat when emplaced thereon by a user. The toilet seat cover has a total flexibility
of less than about 5,000 grams centimeter, and preferably further has an effective
stick time of less than 4 seconds. The toilet seat cover according to the present
invention may further have a lateral wicking capability providing an average absorption
time of less than about 60 seconds and an absorptive capacity greater than about 0.062
grams per square centimeter. The toilet seat cover comprises a cellulosic and/or synthetic
fibrous structure, preferably a cellulosic fibrous structure, having at least two
regions, a high density region and a low density region, wherein the high density
regions are disposed in a series of discontinuous lineaments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] While the Specification concludes with claims particularly pointing out and distinctly
claiming the present invention, it is believed the same will be better understood
from the following description taken in accordance with the accompanying drawings
in which like reference numerals represent the same figure and:
Figure 1 is a top plan view of a toilet seat cover according to the present invention;
Figure 2 is a fragmentary vertical sectional view taken along line 2-2 of Figure 1,
of the toilet seat cover while it is emplaced on a toilet seat (not shown);
Figure 3 is a graphical representation of the data in Table I, showing the inverse
relationship between the toilet seat cover total flexibility and the retention of
the toilet seat cover on a toilet seat tilted at various angles from the horizontal;
Figure 4 is a graphical representation of the data of Table III, showing the direct
relationship between absorption time and the effective stick time of the toilet seat
cover to a synthetic skin laminate or to a glass plate; and
Figure 5 is a graphical representation of the data of Table III, showing the inverse
relationship between absorptive capacity and the aforementioned effective stick time.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Referring to Figure 1, the toilet seat cover 20 according to the present invention
has a generally rectangular, round or oval-shaped perimeter. The toilet seat cover
20 may be shaped like an "0," as shown, or in a less preferred embodiment may be generally
horseshoe shaped.
[0028] As used herein a "toilet seat cover" refers to a unitary structure which has two
forward extending arms 22 joined by at least one transversely extending cross piece
24, so as to fit a split ring toilet seat or at least partially cover a closed figure
toilet seat. As used herein, the terms forward, backward, and transverse (i.e., left
to right) refer to the directions as perceived by a user as he or she is sitting on
the toilet seat. A toilet seat cover 20 according to the present invention does not
include individual strips of toilet tissue laid in various directions to cover (or
partially cover) a toilet seat or tissue strips which were not previously connected
to extend in both the forward to backward and transverse directions (in other than
a generally narrow rectangle).
[0029] Internal to the toilet seat cover 20 is an opening 26 through which the user defecates
and urinates. The opening 26 may be fully or partially covered by an optional flush
flap 28 having a free end. The flush flap 28 is joined, preferably rearwardly, to
the toilet seat cover 20 along a hinged connection 30.
[0030] The toilet seat cover 20 is macroscopically two-dimensional and planar, although
not necessarily flat. The toilet seat cover 20 may have some thickness in the third
dimension. However, the third dimension is very small compared to the actual first
two dimensions or to the capability to manufacture a toilet seat cover 20 having relatively
large measurements in the first two dimensions.
[0031] The toilet seat cover 20 extends longitudinally from a front edge to a rear edge,
having a longitudinal length L of at least about 50.3 centimeters (19.8 inches) and
a transverse width W of at least about 41.9 centimeters (16.5 Inches). This size of
a toilet seat cover 20 having these dimensions allows the toilet seat cover 20 to
longitudinally and laterally overlap the edges of a typical toilet seat.
[0032] The toilet seat cover 20 may be longitudinally and laterally folded at spaced apart
fold lines 34 to allow the toilet seat cover 20 to conveniently fit into a kit or
package for carrying by the user. The fold lines 34 may be spaced apart to allow the
toilet seat cover 20 to be folded and fitted into a package about 10.9 centimeters
(4.3 inches) in length by about 6.4 centimeters (2.5 inches) in width.
[0033] The toilet seat cover 20 preferably comprises a cellulosic fibrous structure. The
fibers are components which make up the toilet seat cover 20 and that have one very
large dimension (along the longitudinal axis of the fiber) compared to the other two
relatively very small dimensions (mutually perpendicular, and being both radial and
perpendicular to the longitudinal axis of the fiber), so that linearity is approximated.
While microscopic examination of the fibers may reveal two other dimensions which
are small, compared to the principal dimension of the fibers, such other two small
dimensions need not be substantially equivalent nor constant throughout the axial
length of the fiber. It is only important that the fiber be able to bend about its
axis, be able to bond to other fibers and be distributed by a liquid carrier.
[0034] The fibers comprising the toilet seat cover 20 may be synthetic, such as polyolefin
or polyester; are preferably cellulosic (to provide flushability) such as cotton linters,
rayon or bagasse; and more preferably are wood pulp, such as soft woods (gymnosperms
or coniferous) or hard woods (angiosperms or deciduous). As used herein, a toilet
seat cover 20 is considered "cellulosic" If the toilet seat cover 20 comprises at
least about 50 weight percent or at least about 50 volume percent cellulosic fibers,
including but not limited to those fibers listed above. A cellulosic mixture of wood
pulp fibers comprising softwood fibers having a length of about 2.0 to about 4.5 millimeters
and a diameter of about 25 to about 50 micrometers, and hardwood fibers having a length
of less than about 1 millimeter and a diameter of about 12 to about 25 micrometers
has been found to work well for the toilet seat covers 20 described herein.
[0035] If wood pulp fibers are selected for the toilet seat cover 20, the fibers may be
produced by any pulping process including chemical processes, such as sulfite, sulphate
and soda processes; and mechanical processes such as stone groundwood. Alternatively,
the fibers may be produced by combinations of chemical and mechanical processes or
may be recycled. The type, combination, and processing of the fibers used are not
critical to the present invention.
[0036] The toilet seat cover 20 according to the present invention may be made of a single
ply of cellulosic fibers having a basis weight of about 0.029 kilograms per square
meter (18 pounds per 3,000 square feet), a machine direction tensile strength of about
91 grams per centimeter (230 grams per inch), and a cross machine direction tensile
strength of about 67 grams per centimeter (170 grams per inch).
[0037] A toilet seat cover 20 according to the present invention may be flushable. Flushable
toilet seat covers 20 comprise cellulosic and other materials which decompose in the
presence of water. Formed films, olefinic materials, and other synthetic materials
(e.g., plastics) which do not, under ordinary conditions, decompose in water, are
not considered to be flushable within the scope of the present invention.
[0038] The toilet seat cover 20 according to the present invention preferably comprises
a single lamina, in order to obviate the use of adhesive in the toilet seat cover
20. Adhesive stiffens the toilet seat cover 20 by increasing its section modulus.
However, it is to be recognized that two single laminae, either or both made according
to the present invention, may be joined in face-to-face relation to form a unitary
laminate. If a laminated construction is selected for the toilet seat cover 20, preferably
the laminae are joined with minimal adhesive, in order to impart the least amount
of stiffness to the toilet seat cover 20. A toilet seat cover 20 according to the
present invention is considered to be a "single lamina" if It is taken off a forming
element during manufacture as a single sheet having a thickness prior to drying which
does not change unless fibers are added to or removed from the sheet. The toilet seat
cover 20 may be embossed, creped, or printed with indicia as desired.
[0039] Referring to Figure 2, the toilet seat cover 20 according to the present invention
has high drapability. Drapability is the tendency of the toilet seat cover 20 to conform,
normal to its plane, to a surface, such as a toilet seat upon which the toilet seat
cover 20 is emplaced. The higher the drapability of the toilet seat cover 20, the
more accurately it will conform to the surface. More accurate conformation to the
surface provides greater retention thereon during the first time period.
[0040] High drapability is reflected by the toilet seat cover's total flexibility, i.e.
the geometric mean of the slope of a particular stress-strain curve of two samples
taken from the toilet seat cover 20. Preferably, the two samples correspond to the
machine and cross machine directions of manufacture, because these directions are
typically in the forward to backwards and transverse directions, respectively. However,
it may not always be possible to determine the machine and cross machine directions
of the toilet seat cover 20. Therefore, any two samples taken from the toilet seat
cover 20 at 90 degree angles from each other will be suitable.
[0041] The samples should be generally square and about 10.2 centimeters by 10.2 centimeters
(4.0 inches by 4.0 inches) in size. If possible the samples should not have fold lines
34, perforations, or other gross deviations from isotropy.
[0042] To determine the total flexibility, each sample is loaded in a tensile machine having
a resolution of at least 1.25 grams. A Thwing-Albert Intellect QCII tensile machine
made by the Thwing Albert Company of Philadelphia, Pennsylvania is suitable. The samples
are loaded so that the tensile load occurs along the machine direction of one sample
and the cross machine direction of the other sample. The cross heads are separated
at a rate of 2.54 centimeters per minute (1.0 inches per minute). A stress-strain
curve is generated. The slope of the stress-strain curve is measured between two points
corresponding to 101.6 grams and 203.2 grams (152.4 grams ± 50.8 grams) force. This
experiment is repeated for the other sample. This measurement may be performed using
Intellect II Standard System Software, APS Version 2.01, available as an option with
the aforementioned tensile machine, or by any comparable software.
[0043] The geometric mean (square root of the product) of the two slopes of the samples
(grams force per square centimeter unit per unit elongation) is determined and reported
in units of grams per centimeter, because the sample width is normalized by the sample
size specified above. For a toilet seat cover 20 according to the present invention,
the total flexibility is less than 5,000 grams per centimeter, preferably less than
2,500 grams per centimeter and more preferably less than 1,000 grams per centimeter.
[0044] A toilet seat cover 20 having such a total flexibility may be manufactured from cellulosic
fibers, provided the toilet seat cover 20 is a single lamina structure of a relatively
low overall density, preferably a density less than about 0.1 grams per cubic centimeter.
Furthermore, the toilet seat cover 20 may be through air dried. A through-air dried
toilet seat cover 20 made upon a drying belt having a particular pattern can cause
hinge lines to form at various angles, increasing the drapability and decreasing the
total flexibility value. It will be apparent to one skilled in the art that creping
will produce hinge lines as the machine direction flexibility is measured and structural
reinforcements to the section modulus as the cross machine direction flexibility is
measured.
[0045] The requisite total flexibility value, and hence drapability, may be achieved by
imprinting a series of discontinuous lineaments into the toilet seat cover 20. Preferably
the discontinuous lineaments locally compact specific regions of the toilet seat cover
20, selectively increasing its density only at such imprinted compacted sites. Such
localized compaction yields a multi-region toilet seat cover 20. Such a multiplicity
of regions increases the drapability, decreases the total flexibility value of the
toilet seat cover 20, and hence improves its ability to conform to the toilet seat
and its ability to remain in position during the first time period.
[0046] Particularly, the imprinted lineaments should preferably extend in both the machine
direction and cross machine direction, so that such lineaments may act as hinge lines
in both directions, allowing the toilet seat cover 20 to conform to the three-dimensional
curvature of a typical toilet seat. Preferably, the compressed lineaments are relatively
closely spaced, e.g., having a pitch of less than 0.6 centimeters (0.25 inches), so
that an accurate approximation of the three-dimensional shape of the toilet seat is
more readily attainable.
[0047] More preferably the toilet seat cover 20 is made in accordance with commonly assigned
U.S. Patent 4,191,609 issued March 4, 1980, to Trokhan, which patent is incorporated
herein by reference for showing a particularly preferred method of manufacturing a
material suitable for use with a toilet seat cover 20 according to the claimed invention.
[0048] With continuing reference to Figure 2, as discussed above it is important the measured
total flexibility reflect the machine direction and cross machine direction drapabilities
of the sample in the final reading, inasmuch as the toilet seat cover 20 preferably
conforms to the toilet seat by draping around the edge of the toilet seat in both
the machine direction and cross machine directions. Such importance is due to the
proclivity of the toilet seat cover 20 to shift in any direction in the presence of
wind forces during the first time period discussed above.
[0049] The proclivity of a toilet seat cover 20 to shift during the first time period described
above can be approximated by its ability to be retained in position on the toilet
seat while it is tilted at various angles relative to the horizontal. To determine
the ability of a toilet seat cover 20 to be retained on a toilet seat tilted at various
angles from the horizontal, a commercially available split ring toilet seat, model
no. 523 sold by the Beneke Division of Sanoerson Plumbing Products Inc. of Columbus,
Mississippi, was positioned on a horizontal surface.
[0050] Four 7.6 by 11.4 centimeter (3.0 by 4.5 inch) samples representing different toilet
seat covers 20 were disposed on this toilet seat, overhanging the nine o'clock position
as the toilet seat is viewed from the in-use position. The long dimension of each
sample was transversely oriented. The short dimension of each sample was oriented
forwards to backwards. The toilet seat was then rotated about its longitudinal axis
L-L until the toilet seat cover 20 sample slid from position. Such rotation approximated
the forces present during the first time period which tend to displace the toilet
seat cover 20 from the desired position.
[0051] The results of this test are recorded in Table I below. Table I shows the total flexibility,
measured as described above, for four toilet seat covers 20 according to the prior
art, three samples of commercially available toilet tissue and one toilet seat cover
20 according to the present invention. Table I also shows the angle at which retention
of the toilet seat cover 20 sample on the toilet seat ceased, as the toilet seat was
rotated prior to displacement of the sample caused by sliding from position.
[0052] Samples I through IV in Table I represent toilet seat covers 20 according to the
prior art. Sample VIII represents a toilet seat cover 20 according to the present
invention.
[0053] Attempts to procure toilet seat covers 20 according to the prior art and having total
flexibilities less than 5,000 grams per centimeter were unsuccessful. However, cellulosic
tissue paper samples large enough for testing were obtained from various other consumer
products and tested as described above. These test results (which do not represent
toilet seat covers 20) are listed as Samples V-VII.
TABLE I
| SAMPLE NO. |
DESCRIPTION (BRAND NAME) |
FLEXIBILITY (G/CM) |
ANGLE (DEGREES) |
| I |
WALGREEN'S |
13,000 |
9 |
| II |
SEATIES |
10,000 |
10 |
| III |
JUST IN CASE |
9,000 |
7 |
| IV |
MY SEAT |
7,000 |
8 |
| V |
RECYCLED SCOTT |
3,000 |
18 |
| VI |
JUST IN CASE TISSUE |
2,000 |
18 |
| VII |
SCOTT REGULAR |
1,000 |
20 |
| VIII |
INVENTION |
700 |
29 |
[0054] Conservative extrapolation of the retention angle of toilet seat covers 20 according
to the prior art towards lower total flexibilities predicts a retention angle of less
than 15 degrees for a toilet seat cover 20 having a total flexibility of 5,000 grams
per centimeter Unexpectedly the toilet seat cover 20 according to the present invention
had a retention angle of at least 29 degrees.
[0055] These data are graphically represented in Figure 3. Samples I through VIII in Figure
3 represent Samples I through VIII in Table I above. The test results for Samples
V-VII confirm the inverse correlation between total flexibility and retention angle
discussed above.
[0056] As is evident from Figure 3, there is a nonlinear inverse correlation between the
total flexibility of a toilet seat cover 20 and its retention angle, i.e., the angle
at which sliding displacement of the sample occurs when the toilet seat is rotated,
with a generally monotonically inverse relationship found therebetween. As can be
seen from Figure 3, a toilet seat cover 20 according to the present invention is far
more likely to be retained in the desired position on the toilet seat without an independent
or separate securing means.
[0057] The proclivity of a toilet seat cover 20 to stick to the user (or to stick to the
toilet seat) during the second time period described above is related to two liquid
handling parameters: its absorptive capacity and the lateral wicking capability of
the toilet seat cover 20. Two other parameters, texture and basis weight, also influence
the proclivity of the toilet seat cover 20 to stick to the user (or to stick to the
toilet seat) during the second time period.
[0058] Particularly with respect to the first two parameters, this proclivity is inversely
proportional to both absorptive capacity and the time it takes water deposited on
the surface of a toilet seat cover 20 to laterally wick throughout the structure.
If water is not absorbed, or wicked away, a film on the surface of the toilet seat
cover 20 may form and cause it to stick to the user or the toilet seat. Alternatively
stated, a toilet seat cover 20 having relatively more hydrophobicity will have a greater
proclivity to stick to the user during the second time period and hence be removed
from the desired position during use.
[0059] The proclivity of a toilet seat cover 20 to stick to the user (or to the toilet seat)
is measured in seconds of effective stick time and determined by the following test.
Eight 7.62 centimeter (3.00 inch) diameter samples are cut from the toilet seat cover
20. Of course, multiple toilet seat covers 20 may be used to acquire a sufficient
number of samples. Care is taken to minimize the number of fold lines 34 or creases
present in the sample.
[0060] Since it is unknown which orientation (right side up or upside down) a user will
emplace the toilet seat cover 20 onto the toilet seat, four samples are tested right
side up, and four samples are tested upside down. The effective stick times are separately
recorded for each side as the average of the four samples tested in the right side
up or the upside down orientations.
[0061] The samples are conditioned at 23 ± 1 degrees C. (73 ± 2 degrees F.) and 50 ± 2 percent
relative humidity for at least two hours. A model skin to toilet seat interface is
made by providing a flat glass base, which serves as the toilet seat. The skin of
the user is simulated by providing a cardboard square having a basis weight of 651
grams per square meter (400 pounds per 3,000 square feet) and being 10.16 centimeters
(4.0 inches) in length on each side. A sheet of 220 grit sand paper is attached to
one side of the cardboard, with the abrasive side of the sand paper facing outward.
Sand paper such as 220SE 3, 210N production paper A weight open coat sand paper made
by the Minnesota Mining & Manufacturing Company of Minneapolis, Minnesota has been
found suitable. A 0.01 millimeter (0.0005 inch) thick clear polyethylene film is tightly
wrapped around the outside of the sand paper and the cardboard, so that the sand paper
is laminated between the cardboard and the polyethylene film. Glad Cling Wrap made
by the First Brands Corporation of Danbury, Connecticut has been found suitable.
[0062] The resulting tri-laminae laminate is hereinafter referred to as the "synthetic skin
laminate." A 550 gram cylindrical weight having a diameter of 4.06 centimeters (1.6
inches) is also provided.
[0063] At the beginning of each test period, the glass surface is washed with liquid dishwashing
detergent, such as Dawn brand dishwashing detergent, available from The Procter &
Gamble Company of Cincinnati, Ohio. The glass surface is then dried with a paper towel.
Before each sample is tested, the glass surface is then wiped on both sides with a
sheet of dryer added fabric softener, such as Downy brand dryer added fabric softener
available from The Procter & Gamble Company. Wiping the glass surface with dryer added
fabric softener eliminates any static charges which may be present. After each of
the samples is tested, the glass surface and synthetic skin laminate are to be blotted
dry with a paper towel.
[0064] The sample to be tested is placed on the flat glass, noting which side faces upward.
This synthetic skin laminate is placed on a flat horizontal surface, with the film
facing upwards. A single drop containing 2 microliters of distilled water heated to
50 ± 4 degrees C (122 ± 8 degrees F) is dispensed onto the center of the synthetic
skin laminate. Dispensing may be accomplished using a 10 microliter glass syringe
having 0.1 microliter graduations. Such a syringe is available from the Precision
Sampling Corporation of Baton Rouge, Louisiana.
[0065] The synthetic skin laminate with the 2.0 microliters is then placed on the center
of the sample, so that the polyethylene film contacts the sample and the center of
the sample corresponds as closely as possible to the center of the area where the
2.0 microliters of distilled water were dispensed. The weight is then placed on top
of the synthetic skin laminate, as close as possible to the center of the synthetic
skin laminate for 10 seconds.
[0066] After 10 seconds the weight is removed and the synthetic skin laminate gently lifted
off the glass and held in position, with the polyethylene film facing downwards. The
time, if any, during which the sample remains stuck to the synthetic skin laminate
is measured and recorded as the effective stick time for that face of that sample.
If the sample sticks to the synthetic skin laminate for more than sixty seconds, this
portion of the test is terminated and the effective stick time for that sample is
recorded as 60 seconds.
[0067] If the sample does not stick to the synthetic skin laminate, one then determines
if it has stuck to the glass. The glass platform is removed from the countertop and
gradually rotated 180 degrees so that the sample now faces downward and the time period,
if any, during which the sample sticks to the glass is recorded. If the sample sticks
to the glass for more than sixty seconds, this portion of the test is terminated and
the effective stick time for that sample is recorded as 60 seconds.
[0068] This procedure Is repeated for the other three samples having the same orientation
of right side up or upside down. If one (or more) sample(s) stick(s) to the glass,
and the other sample (or samples) stick(s) to the synthetic skin laminate, the time
period during which samples stuck to the surface are averaged, without regard to the
difference in surfaces to which the samples stuck. This averaging occurs because the
user will experience discomfort if the toilet seat cover 20 sticks to his or her skin
and likewise will be uncomfortable if the toilet seat cover 20 sticks to the toilet
seat and the user must scrape or peel the toilet seat cover 20 from the toilet seat
to accomplish disposal. The average of these four tests are recorded as the effective
stick time for that face of the toilet seat cover 20.
[0069] This procedure is repeated for the four samples having the opposite orientation.
The effective stick time of these four samples is averaged together to yield an effective
stick time for that face of the toilet seat cover 20.
[0070] Thus, any particular toilet seat cover 20 will have two effective stick times, one
associated with each face of the toilet seat cover 20. The effective stick time of
each face corresponds to testing the toilet seat cover 20 in one of two orientations.
A toilet seat cover 20 according to the present invention has two effective stick
times of not more than 4 seconds, and preferably has two effective stick times of
not more than 2 seconds. Thus, if the effective stick time of either face is less
than 4 seconds, the toilet seat cover 20 meets this criterion of the invention.
[0071] Four commercially available toilet seat covers 20 according to the prior art and
one toilet seat cover 20 according to the present invention were tested as described
above for effective stick time. The results are recorded in Table II below.
[0072] The first column in Table II gives the name of the commercially available toilet
seat cover 20 or designates the toilet seat cover 20 to be according to the present
invention. The first column also designates the two opposed faces of the same toilet
seat cover 20 as "A" and "B." The second column of Table II gives the effective stick
time, in seconds, for the respective face of the sample. The third column gives the
standard deviation of the samples tested for effective stick time as recorded in the
second column. The fourth, fifth and sixth columns designate how many of the samples
tested stuck to the skin laminate, stuck to the glass and and the total that stuck
to either, respectively. The seventh column gives the base size of the samples tested
for each toilet seat cover 20. The eighth column gives the percentage of samples which
stuck to either the skin laminate or to the glass, without regard to the value of
the effective stick time.
TABLE II
| DESCRIPTION/ SIDE |
EFFECTIVE STICK TIME (SEC.) |
STD. DEV. |
NO. STUCK TO SKIN LAMINATE |
NO. STUCK TO GLASS |
TOTAL NO. STUCK |
BASE |
TOTAL PERCENT STUCK |
| MY SEAT A |
26 |
13 |
6 |
2 |
8 |
8 |
100 |
| MY SEAT B |
17 |
17 |
14 |
2 |
16 |
20 |
80 |
| WALGREEN'S A |
49 |
22 |
4 |
3 |
7 |
8 |
88 |
| WALGREEN'S B |
36 |
30 |
3 |
2 |
5 |
8 |
63 |
| SEATIES A |
20 |
17 |
13 |
2 |
15 |
20 |
75 |
| SEATIES B |
23 |
16 |
15 |
1 |
16 |
20 |
80 |
| JUST IN CASE A |
12 |
13 |
11 |
1 |
12 |
20 |
60 |
| JUST IN CASE B |
14 |
17 |
9 |
5 |
14 |
20 |
70 |
| INVENTION A |
1 |
4 |
0 |
3 |
3 |
16 |
19 |
| INVENTION B |
1 |
2 |
0 |
2 |
2 |
16 |
13 |
[0073] Regarding the first liquid handling parameter, the absorptive capacity of the toilet
seat cover 20 is inversely proportional to the proclivity of the toilet seat cover
20 to stick to the user or to the toilet during the second time period. If the absorptive
capacity of the toilet seat cover 20 is too little, even the small amount of moisture
caused by perspiration will overwhelm the ability of the toilet seat cover 20 to laterally
wick away such perspiration and local saturation will occur, causing local sticking
at the sites of saturation.
[0074] For the toilet seat cover 20 according to the present invention, the absorptive capacity
may preferably be at least 0.046 grams per square centimeter (0.298 grams per square
inch), and preferably at least about 0.062 grams per square centimeter (0.398 grams
per square inch). The absorptive capacity of a toilet seat cover 20 is measured according
to the following test.
[0075] A sample support rack is provided. The sample support rack has a plastic rectangular
frame holding a grid of 0.4 millimeter (0.015 inch) diameter monofilament nylon thread.
The thread forms a matrix of 25 by 31 squares, with each square being 1.27 by 1.27
centimeters (0.5 by 0.5 inches) in size. No square in the grid has a thread running
diagonally across it. A complementary sample support rack cover is also provided.
The frames of the sample support rack and sample support rack cover fit together so
that the grids of each capture the samples therebetween.
[0076] A suitable reservoir is filled to a depth of at least 5.1 centimeters (2 inches)
with distilled water. The distilled water is maintained at a temperature of 23 ± 1
degrees C (73 ± 2 degrees F).
[0077] Six 11.4 by 11.4 centimeter (4.5 by 4.5 inch) samples are conditioned for at least
two hours at 23 ± 1 degrees C (73 ± 2 degrees F) and 50 ± 2 percent relative humidity.
[0078] The six samples to be tested are placed on the sample support rack. The samples are
arranged in a 2 x 3 array, so that no sample touches an adjacent sample. Three samples
are oriented with the machine direction parallel to one side of the frame. The other
three samples are oriented with the cross machine direction parallel to the same side
of the frame. The sample support rack cover is placed over the samples. The sample
support rack, sample support rack cover and six samples are collectively weighed to
the nearest 0.01 gram, to yield an initial weight.
[0079] The samples are immersed in the reservoir for 10 seconds. After 10 seconds the samples,
sample support rack and sample support rack cover are gently raised from the reservoir
and maintained in a horizontal position to drain for 120 seconds. During the horizontal
draining period, the frames of the sample support rack and sample support rack cover
are gently blotted to remove excess water from the frames, but not remove water which
was absorbed by the samples.
[0080] The sample support rack, sample support rack cover and samples are then reweighed,
to yield a final weight. The absorptive capacity of the samples in grams per square
centimeter (grams per square inch) is determined by:

where the denominator simply represents the total area of six 11.4 by 11.4 centimeter
(4.5 by 4.5 inch) square samples.
[0081] Regarding the second liquid handling parameter, the lateral wicking capability of
a toilet seat cover 20 is measured in accordance with TAPPI Standard T 432 om-87 using
a 0.01 milliliter drop of distilled water. This test requires ten square 100 x 100
millimeter (3.94 x 3.94 inch) samples taken from one or more like toilet seat covers
20. Preferably each sample is cut so it does not include, or at least minimizes, fold
lines 34 in any direction. Each sample is then tested for its average absorption time.
[0082] The relationship between the average time it takes a drop of water to be absorbed
according to the aforementioned TAPPI test is inversely related to its propensity
not to stick to the skin. A toilet seat cover 20 according to the present invention
has an average absorption time of less than 60 seconds and preferably less than about
10 seconds.
[0083] Four toilet seat covers 20 according to the prior art and one toilet seat cover 20
according to the present invention were tested for the average absorption time as
described in the aforementioned TAPPI Standard T 432 om-87. The test was terminated
at 300 seconds if the drop was not absorbed as required by the test procedure. The
resulting data are tabulated in Table III.
[0084] The first column in Table III gives the sample number. The second column gives the
description of the toilet seat cover 20 from which the sample was taken. The designations
"A" and "B" again refer to opposite faces of the same sample. The third column gives
the average absorption time in seconds as measured according to the aforementioned
TAPPI Standard T 432 om-87. The fourth column gives the standard deviation of the
average wicking times in the third column. The fifth column gives the base size from
which columns 3 and 4 were taken. The sixth, seventh and eighth columns give the horizontal
absorptive capacity in grams per square centimeter, the standard deviation and base
size, respectively. It was assumed that the absorptive capacity of a sample did not
change with the orientation of the sample as it was immersed in the reservoir. Accordingly,
the capacity of side B of each sample is indicated, by ditto marks, to be the same
as side A. The ninth column repeats the effective stick time recorded in Table II
above, for the convenience of the reader.
TABLE III
| SAMPLE NO. |
DESCRIPTION |
WICKING CAPABILITY |
ABSORPTIVE CAPACITY |
EFFECTIVE STICK TIME (SEC.) |
| |
|
AVERAGE ABSORPTION TIME (SEC.) |
STD. DEV. |
BASE |
GRAM/ SQ.CM. |
STD. DEV. |
BASE |
|
| IA |
WALGREEN'S A |
300 |
0 |
5 |
0.035 |
0.002 |
5 |
49 |
| IB |
WALGREEN'S B |
300 |
0 |
5 |
" |
" |
" |
36 |
| IIA |
SEATIES A |
268 |
30 |
5 |
0.025 |
0.001 |
5 |
20 |
| IIB |
SEATIES B |
300 |
0 |
5 |
" |
" |
" |
23 |
| IIIA |
JUST IN CASE A |
160 |
28 |
5 |
0.025 |
0.001 |
5 |
12 |
| IIIB |
JUST IN CASE B |
172 |
36 |
5 |
" |
" |
" |
14 |
| IVA |
MY SEAT A |
170 |
64 |
5 |
0.026 |
0.0 |
5 |
26 |
| IVB |
MY SEAT B |
174 |
20 |
5 |
" |
" |
" |
17 |
| VA |
INVENTION A |
1 |
1 |
5 |
0.069 |
0.005 |
5 |
1 |
| VB |
INVENTION B |
1 |
0 |
5 |
" |
" |
" |
1 |
[0085] These benefits are graphically illustrated in Figure 4. The sample numbers in Table
III correspond to the data points in Figure 4.
[0086] Figure 4 shows a direct correlation between absorption time and effective stick time.
As can be seen, Samples VA and VB according to the present invention had a very low
effective stick time, indicating a propensity not to stick to the user (or to the
toilet seat) during the second time period. Samples VA and VB had the only effective
sticks times less than 10 seconds. Samples VA and VB had the only average absorption
times less than 150 seconds.
[0087] Conversely, Samples IA, IB, IIA, IIB and IVA, each representing a toilet seat cover
20 according to the prior art, had an effective stick time of at least 20 seconds.
Such relatively high effective stick times indicate a proclivity of the toilet seat
cover 20 to stick to the user (or to the toilet seat) during the second time period
and illustrate the drawbacks of toilet seat covers 20 according to the prior art when
compared to toilet seat covers 20 according to the present invention.
[0088] All of these toilet seat covers 20 according to the prior art had absorptive capacities
0.035 grams per square centimeter or less. Similarly, these toilet seat covers 20
had the relatively high effective stick times discussed above.
[0089] There is an inverse relationship between effective stick time and absorptive capacity.
This relationship is graphically illustrated in Figure 5. Again, the Sample Numbers
from Table III correspond to the data points in Figure 5.
[0090] Figure 5 shows the benefits of a toilet seat cover 20 according to the present invention.
A toilet seat cover 20 having a greater absorptive capacity has a lesser effective
stick time, indicating a lesser proclivity to stick to the user or to stick to the
toilet seat during the second time period.
[0091] It will be apparent to one skilled in the art that many variations of the claimed
invention are feasible. For example, the effective stick times of opposite faces of
the toilet seat cover 20 may be the same or different, the toilet seat cover 20 may
have a greater basis weight in the area corresponding to where the user's buttocks
reside during use than in the area where the user's legs reside during use, etc. All
such variations are within the scope of the appended claims.
1. Dispositif de recouvrement de lunette de W.-C. (20) destiné à isoler un utilisateur
de lunette de W.-C., pouvant être drapé de façon à épouser sensiblement la forme d'une
lunette de W.-C. lorsqu'il est placé sur celle-ci par un utilisateur, caractérisé
en ce que ledit dispositif de recouvrement de lunette de W.-C. a une flexibilité totale
inférieure à environ 5000 grammes par centimètre et, de préférence, inférieure à 2500
g par centimètre et, plus préférablement inférieure à 1000 grammes par centimètre,
et en ce que ledit dispositif de recouvrement de W.-C. comprend une structure fibreuse
cellulosique et/ou synthétique.
2. Dispositif de recouvrement de lunette de W.-C. (20) selon la revendication 1, caractérisé
en ce que ledit dispositif de recouvrement de lunette de W.-C. a un temps d'adhérence
effectif qui n'est pas supérieur à 4 secondes et, de préférence, a un temps d'adhérence
effectif qui n'est pas supérieur à 2 secondes.
3. Dispositif de recouvrement de lunette de W.-C. (20) selon les revendications 1 et
2, caractérisé en ce que ledit dispositif de recouvrement de lunette de W.-C. a une
capacité d'absorption supérieure à 0,046 gramme par centimètre carré et, de préférence,
a une capacité d'absorption supérieure à 0,062 gramme par centimètre carré.
4. Dispositif de recouvrement de lunette de W.-C. (20) selon les revendications 1, 2
et 3, caractérisé en ce que ledit dispositif de recouvrement de lunette de W.-C. a
une capacité d'effet de mèche latérale qui assure un temps d'absorption moyen inférieur
à 60 secondes et, de préférence, a une capacité d'effet de mèche latérale qui assure
un temps d'absorption moyen inférieur à 10 secondes.
5. Dispositif de recouvrement de lunette de W.-C. (20) selon la revendication 1, dans
lequel ledit dispositif de recouvrement de W.-C. comprend une structure cellulosique.
6. Dispositif de recouvrement de lunette de W.-C. (20) selon la revendication 5, dans
lequel ladite structure fibreuse cellulosique présente au moins deux régions, une
région à haute densité et une région à basse densité, ledit dispositif de recouvrement
de lunette de W.-C. ayant, de préférence, une flexibilité totale inférieure à 2500
grammes par centimètre et, plus préférablement, ayant une flexibilité totale inférieure
à 1000 grammes par centimètre.
7. Dispositif de recouvrement de lunette de W.-C. (20) selon la revendication 6, qui
a un temps d'adhérence effectif qui n'est pas supérieur à 4 secondes et, de préférence,
qui a un temps d'adhérence effectif qui n'est pas supérieur à 2 secondes.
8. Dispositif de recouvrement de lunette de W.-C. (20) selon les revendications 6 et
7, caractérisé en ce que lesdites régions à haute densité sont placées en linéaments
discontinus.
9. Dispositif de recouvrement de lunette de W.-C. (20) selon la revendication 8, caractérisé
en ce que lesdites régions à haute densité s'étendent à la fois dans le sens machine
et dans le sens transversal à la machine.
10. Dispositif de recouvrement de lunette de W.-C. (20) selon l'une quelconque des revendications
précédentes, qui peut être évacué par chasse d'eau.