Flushable Fabric

Abstract

A sanitary napkin designed for disposal in conventional toilet systems. A conventional pad is enclosed in a wrapper comprising a web of nonwoven fibers discontinuously bonded with a water-sensitive adhesive that is relatively more soluble in cold water than in warm water. The napkin is used with supplementary support means.

Description

This invention relates to sanitary napkins and, more particularly, to a sanitary napkin with a flushable wrapper.

Absorbent pads, such as sanitary or catamenial napkins, are customarily enclosed in a fluid-pervious wrapper. This wrapper serves several functions. It hold together the various components making up the functional elements of the pad; and, in addition, it may provide extensions beyond each end of the pad which serves as tabs for attachment of the pad to the suspension device, such as a sanitary belt, whereby the pad may be suitably positioned against the body of a wearer. The wrapper must permit the body exudate to pass through into the absorbent pad under the normal conditions of usage and preferably has little absorbent capacity in itself so that the surface remains relatively dry in use, i.e., absorbed fluids should not wick along fibers in wrapper.

Various materials have been used for wrappers. These include woven gauze, nonwoven adhesively bonded thread webs, woven thread webs adhesively stabilized at the thread intersections, nonwoven carded fiber webs, knit fabrics, and the like.

While certain of these wrapper materials have functioned in a satisfactory manner, one universal problem has arisen. The disposability has been a messy, disagreeable task. While the absorbent pad element itself may be easily disposed of by flushing in the conventional toilet system, the pad wrapper must first be separated from the pad and disposed of by other means. Conventional wrappers are generally of woven or knitted construction, or are bonded together by a strong, permanent adhesive to provide the requisite strength in use and, therefore, cannot be deposited in the toilet system because of obvious plugging problems, which would result. Such wrappers also are generally not biodegrable and, even if successfully flushed into a septic system, will hasten the need for periodic cleaning. Disposal of the conventional sanitary napkin by flushing therefore involves separating the wrapper from the pad, depositing the pad in the toilet system and then separately disposing of the wrapper in a waste basket or by other means.

Previous attempts to provide a "flushable" pad wrapper have been successful in providing flushability, but only at the expense of other desirable features. If made strong enough to support the pad by taps alone, permeability is reduced and the water soluble adhesive dissolves too slowly for rapid flushability. If made sufficiently permeable, the wrapper is too weak for tap support.

It is accordingly an object of the present invention to provide a sanitary napkin pad and wrapper therefore which may be readily disposed of in conventional toilet systems.

A more specific object is to provide a sanitary napkin pad and flushable wrapper which may be advantageously used in connection with a supplemental supporting device.

A further object is to provide a sanitary napkin pad and flushable wrapper which may be economically manufactured.

A still further object is to provide a flushable sanitary napkin pad wrapper having the hereinbefore described characteristics which has improved permeability.

Other objects and advantages of the invention will be understood by reference to the following specification and accompanying drawings, in which:

FIG. 1 is a perspective view of one embodiment of the present invention and illustrating a pad with short tabs at both ends;

FIG. 2 is a perspective view of another embodiment of the present invention and showing a pad wrapper with a short tab on one end;

FIG. 3 is a front elevation of a bikini-type panty in the approximate shape the panty assumes on a wearer during use and showing the relative location of the attachment means that are used to hold a sanitary napkin of the type shown in FIG. 2 in position;

FIG. 4 is an enlarged view taken of the interior of the front portion of the panty shown in FIG. 3;

FIG. 5 is a plan view of one embodiment of the means for attaching the sanitary napkin to the bikini-type panty shown in FIG. 3;

FIG. 6 is a plan view of another type of supporter which may be used with the double short tab construction of FIG. 1 and;

FIG. 7 is a perspective view of the holder of FIG. 6 in the approximate position it would assume on wearer's body (and with pad in place).

While the invention will be described in connection with certain preferred embodiments, it should be understood that this invention is not intended to be limited to the particular embodiments disclosed, but, on the contrary, it it intended to cover the various modifications and equivalent arrangements included within the spirit and scope of the invention.

In accordance with one feature of the present invention, the pad wrapper comprises a nonwoven web of textile type, staple fibers bonded with a binder that is more soluble in cold water than in hot water. To this end, a nonwoven web is provided which is formed of staple fibers of varying length and having an average length of about 11/2 inches. The web should be relatively lightweight, i.e., less than about 1 ounce per square yard and preferably about 1/2 ounce per square yard or less. To provide the requisite strength, the fiber should be oriented in the web to provide a machine direction strength that is generally about four or five times that of the cross direction. A machine direction strength of about 2 pounds/inch of width is satisfactory. Higher strengths are, of course, preferred.

While any means may be employed to form the base web, the desired strength and weight can be readily obtained by combining a number of carded webs. The denier of the staple fibers may vary from about 1 to about 8, with a denier of less than about 2 being preferred. While rayon fibers are preferred, other types of synthetic fiber may be employed either alone or in combination.

To bond the fibers together to achieve the strength levels required, a water-sensitive adhesive such as polyvinyl alcohol or methyl cellulose is employed. The adhesive preferably is printed on or otherwise applied to provide discontinuous bonding which is preferred. When such discontinuous bonding is used it is preferable that less than about 40 percent of the area of the web be covered with the adhesive, preferably about 25 percent or less. The weight of the adhesive should be about 10 percent or less by weight of the fibers. Carded webs may also be sprayed with adhesive but this gives a stiffer, less satisfactory product.

In the preferred embodiment, polyvinyl alcohol is the adhesive that is employed. This may be applied to the web by rotogravure printing employing a polyvinyl alcohol-water solution with from about 5 to 15 percent solids. To improve the softness, a plasticizer such as glycerine or the like may be substituted for a minor percentage of the polyvinyl alcohol, from about 5 to 10 percent generally being sufficient. It has been found particularly advantageous to employ a polyvinyl alcohol which has a percent hydrolysis of from 79 to 82 and a viscosity (4 percent water solution at 20.degree. C.) of from 22 to 26 c.p.s. PVA of such composition dissolves more readily in cold water than it does in warm water.

To further enhance the softness of the wrapper material it is preferred to "work" the bonded web such as embossing, creping, use of breaker rolls and the like. It has been found that needling or "pin embossing" is particularly advantageous in that it reduces stiffness by as much as about 50 percent or more while at the same time improving the performance of the wrapper material by increasing the porosity.

Now turning to the drawings, FIGS. 1 and 2 illustrate two embodiments of wrappers that may be employed in accordance with the present invention. In FIG. 1, a pad is enclosed in a nonwoven web bonded by a water-soluble adhesive of the type hereinbefore described. Thus, a wrapper 10 has short tabs 12, 12' extending from both ends of the pad. The edges of the wrapper 10 will generally overlap and may be bonded by a line of adhesive running the length of the overlap, as shown at 14. In FIG. 2 a pad is enclosed by a wrapper 20 having a single short tab 22 extending from one end of the tab.

The construction of the pad itself is not critical and many suitable constructions are well know. As an example, the absorptive pad could comprise multiple plies of cellulose wadding with a central pad of wood fluff. Other known absorbent materials such as batts of cotton and/or various types of synthetic fibers may also be used for the main or central portion of the pad.

While the water-sensitive adhesives that have been described and which are employed in the wrapper shown in FIGS. 1 and 2 are more soluble in cold water than in hot, the passage of the body exudate through the wrapper may well cause a sufficient decrease in strength so that a pad wrapper using such adhesives and having a long tab constitution could not be employed in the conventionally used suspension devices. In accordance with the present invention, a wrapper with a short tab construction is utilized in connection with a supplemental supporting means.

FIGS. 3 through 5 show one embodiment of a supplementary means for the wrapper with the tab construction shown in FIG. 2. As illustrated in FIG. 3, the support includes a panty 30 of a bikini-type construction with a rear panel 32, a front panel 34, side seams 36, a crotch piece 38, a waistband 40 and leg openings 42. The garment may be made of stretch yarn and have a reinforced construction in the crotch area 44 such as a double-ply of material starting at seam 46 and extending a similar distance to a seam at the rear of the garment. At the seam, where there is adequate strength of fabric, there is secured a fastener 48 through which a short tab end 50 of the sanitary napkin 52 is threaded.

As is shown in FIGS. 4 and 5, the fastener 48 is of a flat, generally oblong configuration and comprises a pair of side bard 54, 54' interconnected at their lower ends by transverse bar 58 to form aperture 60. The opposite or upper end of the side bars is provided with a split top bar in the form of end bars 62, 62' extending toward each other to form an access slot 64 above aperture 60. This fastener may be attached to the front portion of the panty by any suitable means such as by threads not shown.

FIGS. 6 and 7 illustrate a suitable supporting means for the pad wrapper of FIG. 1.

The support comprises a backing member generally indicated at 70 formed as a laminate of a fluidproof plastic layer on the inner side and a cotton backing layer on the outside. The forward end 72 of the backing member is wider than the rear end 74 and each end is formed with two slots 76 and 78 respectively to receive the ends of the two straps 80 of an elastic material, the length of the straps being adjustable by means of buckles 82.

The support is provided with two tabs 84 adjacent each and, each tab being formed with one half of a press-stud 86 arranged to engage with a corresponding half of the backing member so that the tabs 88 of a sanitary napkin 90 can be held by the studs 18 against the backing member as can be seen in FIG. 1.

The spacing and angulation of the slots 76 and 78 allow the straps 82 to assume a position in which, when the holder is in use (see FIG. 7), they extend around the front of each leg of the wearer at approximately the crease line where the top of the leg is jointed to the body, and around the back. As the two front slots 76 are spaced apart further than the two rear slots 78, the suspension for the backing member is very comfortable and does not chafe. At the same time "roping" or twisting is prevented because of the spacing apart of the two rear slots 78.

The side edges of the backing member are bound with a fabric bias tape so as to provide a rim which not only helps to connect the layers of the backing member together, but also means that the holder, when in use, "cups" or "cradles" the sanitary napkin to help prevent leakage from the sanitary napkin.

Thus, as has been seen, the present invention provides a sanitary napkin pad and a wrapper material therefore which may be both readily disposed of by placing in a conventional toilet system yet which has the requisite durability and strength in conjunction with a supplementary support means. The napkin thus may be readily disposed of in a toilet.

Claims

I claim as my invention:

1. A supported catamenial absorption device comprising the combination of an absorbent pad, a fluid pervious wrapper enclosing the pad and having at least one short tab located on at least one end of the absorbent pad, said wrapper being comprised of staple fibers discontinuously bonded with a water sensitive adhesive in an amount insufficient to provide adequate strength to support the pad in use, a supplementary support means to provide support for the wrapped pad in use and attachment means for holding the tab to maintain the wrapped pad in position adjacent the supporting means.

2. The device of claim 1 wherein the adhesive is relatively more soluble in cold water than in warm water.

3. The device of claim 2 wherein tabs extend from both ends of the absorbent pad.

4. The device of claim 1 wherein the adhesive forms a series of discrete lines.

5. The device of claim 1 wherein the adhesive is polyvinyl alcohol.

6. The device of claim 3 wherein the polyvinyl alcohol has a percent hydrolysis of from about 79 to 82 and a viscosity of from about 22 to 26 c.p.s.

7. The device of claim 6 wherein the adhesive is present in an amount up to about 10 percent by weight of the fibers and comprises up to about 40 percent of the wrapper surface area.

8. The device of claim 1 wherein the support means comprises a panty having a waistband, leg openings and crotch area defined by front and back seams extending transversely of the garment.

9. The device of claim 3 wherein the support means comprises an elongated body portion with one end broader than the other and being formed with slots and support straps having ends which are received in the slots.