WO1994024919A1

WO1994024919A1 - Toilet seat cover

Info

Publication number: WO1994024919A1
Application number: PCT/US1994/004768
Authority: WO
Inventors: Mark John Steinhardt
Original assignee: The Procter & Gamble Company
Priority date: 1993-05-04
Filing date: 1994-04-28
Publication date: 1994-11-10
Also published as: AU688769B2; CA2161766A1; DE69415006D1; DE69415006T2; EP0697832B1; CA2161766C; AU6822394A; MX9403258A; NZ266631A; JPH08509640A; EP0697832A1

Abstract

A drapable toilet seat cover (20) which conforms to the shape of the toilet seat. By conforming to the shape of the toilet seat, the toilet seat cover remains in position after being emplaced by the user. The toilet seat cover (20) may also wick away perspiration, to prevent it from sticking to the user and moving from position during use.

Description

TOILET SEAT COVER

FIELD OF THE INVENTION

The present invention relates to toilet seat covers emplaced over a toilet seat to insulate the user therefrom. BACKGROUND OF THE INVENTION

Toilet seat covers are well known in the art. Toilet seat covers are typically used in a public restroom where the user may 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

BRIEF SUMMARY OF THE INVENTION

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 wieking 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 may comprise 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

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

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.

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).

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.

A toilet seat cover 20 according to the present invention 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.

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.

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.

The toilet seat cover 20 may comprise 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.

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 1 inters, 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.

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.

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). 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

DESCRIPTION FLEXIBILITY ANGLE

SAMPLE NO. (BRAND NAME) (G/CM) (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

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.

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.

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. 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

EFFECTIVE NO. STUCK

DESCRIPTION/ STICK STD. TO SKIN NO. STUCK TOTAL NO. TOTAL PERCENT SIDE TIME (SEC.) DEV. LAMINATE TO GLASS STUCK BASE 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

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.

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.

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.

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).

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.

The six samples to be tested are placed on the sample support rack. The samples are arranged in a 2 × 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. 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.

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:

(final weight - initial weight)/779.8.

where the denominator simply represents the total area of six 11.4 by 11.4 centimeter (4.5 by 4.5 inch) square samples.

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 × 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.

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.

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.

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 I I I

WICKING ABSORPTIVE CAPABILITY CAPACITY

EFFECTIVE

AVERAGE STICK ABSORPTION STD. GRAM/ STD. TIME

SAMPLE NO. DESCRIPTION TIME (SEC.) DEV. BASE SO.CM. DEV. BASE (SEC.)

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

These benefits are graphically illustrated in Figure 4. The sample numbers in Table III correspond to the data points in Figure 4.

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.

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.

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.

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.

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.

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.

Claims

What is claimed is:

1. A toilet seat cover for insulating a user from a toilet seat, said toilet seat cover having a total flexibility of less than about 5,000 grams per centimeter and being drapable to substantially conform to the shape of a toilet seat when emplaced thereon by a user, said toilet seat cover preferably having a total flexibility less than 2,500 grams per centimeter and more preferably having a total flexibility less than 1,000 grams per centimeter.

2. A toilet seat cover according to Claim 1 characterized in that said toilet seat cover has an effective stick time of not more than 4 seconds and preferably has an effective stick time of not more than 2 seconds.

3. A toilet seat cover according to Claims 1 and 2 characterized in that said toilet seat cover has an absorptive capacity greater than 0.046 grams per square centimeter and preferably has an absorptive capacity greater than 0.062 grams per square centimeter.

4. A toilet seat cover according to Claims 1, 2 and 3 characterized in that said toilet seat cover has a lateral wicking capability providing an average absorption time of less than 60 seconds and preferably has a lateral wicking capability providing an average absorption time of less than 10 seconds.

5. A toilet seat cover for insulating a user from a toilet seat, said toilet seat cover having a total flexibility of less than 5,000 grams per centimeter and being drapable to substantially conform to the shape of a toilet seat when emplaced on by a user, said toilet seat cover comprising a cellulosic fibrous structure having at least two regions, a high density region and a low density region, said toilet seat cover preferably having a total flexibility less than 2,500 grams per centimeter, and more preferably having a total flexibility less than 1,000 grams per centimeter.

6. A toilet seat cover according to Claim 5 having an effective stick time of not more than 4 seconds and preferably having an effective stick time of not more than 2 seconds.

7. A toilet seat cover according to Claims 5 and 6 characterized in that said high density regions are disposed in discontinuous lineaments.

8 A toilet seat cover according to Claim 7 characterized in that said high density regions extend in both the machine direction and the cross machine direction.

9 A toilet seat cover according to any of the foregoing claims which is flushable.

10. A toilet seat cover according to any of the foregoing claims which comprises cellulose fibers.