IE47704B1 - Disposable pilch - Google Patents

Abstract

A unitary disposable pilch comprises a waterproof sheet 2 and a waterpermeable sheet 1 enclosing an absorbent pad 3. Two elastic elements e.g. rubber bands are attached to the waterproof sheet adjacent a longitudinal edge of the pad, and spaced from a said edge at least in the crotch portion at a distance between 13 mm and 19 mm. These elements improve the water tightness of the crotch portion.

Description

This invention relates to a unitary disposable pilcb with elastic means for providing watertightness at the crotch of the wearer, and particularly relates to a pilch comprising means allowing watertightness of the crotch to be improved.

Numerous attempts have been made to achieve napkin structures whereby when worn leakages of urine may be avoided or whereby the urine is directed preferentially towards the most absorbent zones of the napkin. However relatively few disposable pilches are commercially available, and the possibilities of choice for mothers of young children are thus reduced to purchase of an inefficient if inexpensive napkin-pants combination, or expensive functional models.

While it is possible to use conventional foam cellulose napkins which are placed inside waterproof pants, experience has shown that such combinations, while at first sight being cheaper, cause much unpleasantness including soiling of the pants, yellowing, excessive compression of the baby's legs, and uncontrollable leakages.

Mothers of young babies are currently being offered «···? unitary ^combinations comprising the napkin and waterproof protection. These provide disposable pilches comprising layered, structures comprising plastics e.g. polyethylene sheet'—absorbent pad—fluid-permeable non-woven material, of rectangular initial shape modified by special folds • ·· adapted io’the'anatomy of the baby. 7 7 0 4 - 3 Thus our published French Patent Specification 2,219,636 describes a napkin-pants combination (disposable pilch) of triangular shape which provides a satisfactory performance but which is difficult to produce on a large scale.

French Patent Specification 2,063,794 describes a napkin-pants combination including two rectangular portions connected to each other by a zone of reduced width by concave portions along its longitudinal edges including an absorbent strip. The concave portions of the edges, with other edges, are provided with an elastic tape formed from latex threads. Figure 1 of this patent specification shows that the edges of the absorbent strip become removed from the concave elastic edge parts and a Speci fi cati on flap forms similar to that described in Patent/No. 40127. Moreover fixing elastic threads along concave edge portions is difficult in large-scale production.

Numerous documents described napkin supports or pants having elastic side edges, for example U.S. Patents Nos. 2,419,867; 2,509,674; 2,675,805; 2,969,065 and 3,000,381.

It has also been proposed in U.S. Patent 3,828,784 to produce micro-creping of the edges of a unitary napkin in order to confer some elasticity to the crotch zone, but again high-speed production of such a construction is not a viable proposition.

Another proposal is in U.S. Patent 3,776,232. At the level of the zone of the side edges of the unitary napkin, to be located near the baby's legs, a supplementary adhesive is applied allowing the opening formed to be reduced when the napkin is positioned on the baby.

Such an expedient however does not allow watertightness - 4 to be maintained with movement of the wearer and the adhesive is not sufficiently effective for resisting the resulting strains. When the adhesive becomes unstuck, the napkin loses a large part of its effectiveness.

Speci fi cati on The aforementioned Patent/No. 40127 describes a disposable napkin-pants combination, comprising an elastically contractable flexible flap along each of the side edges. Formation of the flap takes place only when an elastic element is located at a sufficient distance from the edge of the absorbent pad. Although it improves watertightness of the crotch, a napkin-pants combination of this kind has the disadvantage of not making the absorbent pad sufficiently adaptable to the anatomy of the wearer, the elastic element acting only on the flexible flap. The tendency to form a pocket at the crotch hereinbefore referred to in other models, becomes accentuated. Furthermore when urine penetrates into the flap this zone of the napkin-pants combination, being of insufficient capacity, becomes rapidly saturated and a greater area of the baby's skin becomes in contact with the urine.

To avoid such a disadvantage, another proposal consists in avoidance .of .the formation of a flexible British Specification flap, as described in I Patent/No. 1,561,081. A unitary disposable napkin of absorbent strip between a porous sheet and a waterproof sheet, includes at each end a planar waistband section and a non-planar crotch section between the ends, the crotch section being longitudinally compressed by extensible elastic elements fixed adjacent to each edge of the absorbent strip so as to produce a series of bulky transverse corrugations placed one against the other along the crotch section. - 5 In this construction the elastic means is disposed as close as possible to the edge of the pad in the crotch zone.

In such an arrangement, the elastic bands allow maximum compression of the absorbent strip since the taking up of the compressive forces of the elastic element will be affected by deformation of the sheet supporting it (waterproof sheet or porous sheet).

Nevertheless the formation of bulky transverse corrugations has the disadvantage of weakening the strip of absorbent material.

Furthermore the different operations of manufacture of a disposable pilch (e.g. deposition, adhesion and cutting of the different constituent elements) are performed in the stretched state of the elastic elements.

At the end of these operations, there is suppression of tension, the combinations are then folded and packed with the elastic elements in the slack state. Subsequently in use there is again application of tension when the mother stretches the napkin to put it on the child, and finally a further at least partial, slackening of tension once the napkin is in position on the child.

It has been observed that this succession of application and release of tension involves a risk of tearing the absorbent pad in its median portion, at crotch level, which is precisely where the effect of absorbent material is most required. This risk is due to the poor cohesion of the mass of cellulosic fibres constituting the absorbent pad.

Another disadvantage of such a construction is that when the elastically extensible elements are located immediately next to the longitudinal edges of the absorbent pad, these elements are not applied directly to the baby's skin and press on the latter through all or part of the thickness of the interposed pad. This has the effect of reducing watertightness in the crotch section, which reduction in watertightness may be aggravated by the effect of undulation of the pad resulting from its compression.

The present invention is directed to a unitary disposable pilch with elastic means for watertightness at the crotch of the wearer, by which the disadvantages referred to are mitigated, and in particular avoids the presence of a flap such as described in the said Patxr§?lto.C 10127, and the formation of transverse corrugations such as British Specification described in the said / Patent/No. 1,561,021.

The invention provides a unitary disposable pilch as set forth in Claim 1 hereof.

The invention is hereinafter described and illustrated in the accompanying drawings, of which Figure 1 is a schematic plan view of one embodiment of a napkin-pants combination according to the invention, Figure 2 is a sectional view of Figure 1 along the line AA, and Figures 3 and 4 illustrate dimensional relationships of Figures 1 and 2 respectively.

Referring to Figures 1 and 2, the unitary pilch is constituted by an absorbent pad 3 of width 1, e.g. of rectangular shape, and uniform thickness e, positioned between a liquid-permeable upper sheet 1 and a waterproof sheet 2.

At a crotch portion cutaway portions 4 and 5 on the longitudinal edges of pad 1 are provided so as to approximate to a pants shape when the combination is folded in use. The cutaways as shown are concave in shape, although they may be of rectangular or other suitable configuration.

Elastically extensible elements (for example natural or synthetic rubber bands) 6 and 7 are stuck in the stretched state on sheets 2 e.g. with a hot-melt adhesive or by other means, at a distance between 13 mm and 19 mm from the longitudinal edges of the absorbent pad, so as to avoid the formation of transverse creases over the full width of the crotch portion, the return forces of the elastic elements being substantially absorbed by deformation of sheet 2, to avoid gathering of the said sheet elements adjacent to the absorbent pad.

It is to be emphasised that it is only in the crotch portion of the combination that this distance criterion must be complied with. In the end portions of the combination, the absorbent pad may be wider, e.g. of a width similar to the width of the napkin. In such a construction dimensional restraint imposed by spacing of the elastic elements with respect to the pad is not necessary.

Preferably the distance between an elastic element and the corresponding longitudinal edge of the absorbent pad is about 15 mm.

Fixing of the absorbent pad 3 onto the waterproof sheet 2 is obtained by applying lines of adhesive of the hot-melt type or the like to sheet 2. The procedure is the same for adhesion of the permeable sheet 1 on sheet 2.

The pad 3 may be stuck to the waterproof sheet 2 over its whole length. It may likewise be stuck along a transverse central strip, the ends of the pad being stuck neither to the upper sheet 1 nor to the lower sheet 2. 4*7704 - 8 The pad of absorbent material 3 may be a pad of reticulated cellulosic fibres according to French Patent Specification 2,328,796 in the name of the applicant.

Consolidating means -which are in themselves known 5 may be used to increase its cohesion, e.g. by addition of binders or passage of water vapour through the pad followed by calendering. Xt is also possible to position the pad between two sheets of non-woven material or fleecy fabric to facilitate handling. The waterproof surface may consist of a sheet of plastics material for instance polyethylene, or be produced in situ by spraying on a hydrophobic latex, or a sizing agent as used in papermaking .

The permeable surface generally may consist of a conventional non-woven material, or preferably a nonv/oven material composed of a polypropylene mesh reinforced with polyamide filaments as described in French Patent Specification 2,195,555 in the name of the applicant, associated on one side with thermoplastic fibres.

Figures 3 and 4 illustrate the dimensional characteristics of preferred embodiments of the napkin.

In the table of dimensions hereinafter set forth Ll is the total length of the napkin, and L2 the total width.

The pad has a length 1^, a width 1% and a thickness e. The permeable upper sheet, which may be a sheet of non-woven material, has a length equal to that of the napkin Lj and a width Int slightly less.

The elastically extensible elements are natural or synthetic rubber bands of thickness μ, and width a, and are glued over a length with the reference lc at a distance d from the longitudinal edges of the absorbent pad.

The crotch cutaway has a length LD and a depth or width ID.

Examples of Dimensions of Napkin-Pants Combinations According to Invention Combination A B total length Ll (mm) 490 540 total width L2 (mm) 300 330 10 Pad length 1^ (mm) 410 470 width 12 (mm) 145 160 thickness e (mm) 8 to 9 9.5 to 10. weight of pad (g) 30 to 35 50 to 55 15 Permeable Upper Sheet width Int (mm) 295 325 Elastic Elements thickness μ (mm) 25/100 ths 25/100 ths width a (mm) 6 6 20 length of gluing le (mm) 260 300 retracted length under tension (mm) 140 165 distance in relation to pad d (mm) 15 15 25 Crotch Cutaway length LD (mm) 300 310 depth ID (mm) 42 49

Claims (3)

1. CLAIMS : 1. A unitary disposable pilch comprising a waterproof sheet element and a liquid-permeable sheet element together enclosing an absorbent centrally-disposed pad 5 extending longitudinally of the pilch across a crotch portion and including elastic means to ensure good contact of the combination at the crotch of the wearer, characterised in that the said elastic means are provided by two elastically extensible elements attached to the said water 10 proof sheet element, each located adjacent to a longitudinal edge of the said pad, and spaced from a corresponding said edge of the absorbent pad at least at a crotch portion of the combination at a distance between 13 mm and 19 mm beyond the respective edge, and in that the 15 tension in the elastic means is such as to avoid the generation of corrugations in the said two sheet elements adjacent to the absorbent pad at the crotch portion.

2. A pilch according to Claim 1, wherein each elastically extensible element is spaced from a corres20 ponding edge of the absorbent pad by a distance of about 15 mm.

3. A pilch as claimed in Claim 1, substantially as hereinbefore described and illustrated in the accompanying drawing.