WO1995031164A1

WO1995031164A1 - Absorbent article

Info

Publication number: WO1995031164A1
Application number: PCT/SE1995/000540
Authority: WO
Inventors: Christer Karlsson; Cécile SANDIN; Robert Kling; Ing-Britt Magnusson
Original assignee: Mölnlycke AB
Priority date: 1994-05-16
Filing date: 1995-05-15
Publication date: 1995-11-23
Also published as: IL113655A0; SE502774C2; SE9401679L; SE9401679D0; GB2289417A; TNSN95053A1; AU2542395A; GB9509783D0; ZA953707B

Abstract

A disposable absorbent article (10) is disclosed which has an absorbent core (12) enclosed by a liquid-permeable topsheet (14) and a liquid-impermeable backsheet (16). The topsheet and backsheet extend beyond the absorbent core to join together to form a peripheral margin (18) extending around at least a portion of the absorbent core (12). Elastic means (22) are provided which run substantially the entire length of the article. So that the article adopts a bowl shape in use, the elastic means (22) define an outwardly convex curved path on either side of the longitudinal axis (20).

Description

TITLE: Absorbent article

TECHNICAL FIELD:

The present invention relates to an absorbent article, such as a disposable incontinence guard, according to the preamble of claim 1. An absorbent article of this type is known for example from EP-A-0 273 963.

BACKGROUND OF THE INVENTION:

In recent years, as incontinence guards and sanitary napkins have become thinner and thinner, the risk of lateral leakage has increased. Attempts have been made to address this problem by providing incontinence guards and sanitary napkins which in use more closely follow the shape of the wearer's body. Such articles are generally provided with a relatively thick midsection which maintains contact with the wearer. These articles are, however, still subject to lateral leakage when fluid discharge is great. In addition, these articles are considered by many to be too bulky.

Thin, generally planar incontinence guards are known in which side leakage protection is provided in the form of longitudinal compressed areas which serve to rapidly distribute the fluid over a large area of the incontinence guard. These compressed areas are, however, far from sufficient to satisfactorily eliminate lateral leakage.

In EP-A-0 091 412, one method of hindering side leakage is proposed. Said document discloses a sanitary napkin having an absorbent core totally enclosed by a liquid-permeable topsheet and a liquid-impermeable backsheet. The topsheet and backsheet are more expansive than the absorbent core and join together to form a peripheral margin extending around the entire absorbent core. In its longitudinal direction, the napkin is provided with pretensioned elastic means which extend along the peripheral margin on either longitudinal side of the absorbent core within the mid portion of the napkin. When the napkin is in use, the pretensioned elastic means cause the lateral margins of the napkin to fold upwards to thereby create lateral barriers along the mid portion of the napkin which serve to retain the discharged fluid.

Whilst the sanitary napkin according to EP-A-0 091 412 is reasonably successful in hindering lateral leakage at the mid portion of the napkin, it is still possible that discharged fluid may spread longitudinally along the napkin and past the lateral barriers, thereby exposing the wearer of the napkin to possible leakage.

In an effort to retain discharged fluid in the mid portion of an absorbent article, it is known from EP-A-0 273 963 to provide elastic elements which extend from a point on the longitudinal axis of symmetry of the article in the vicinity of the transverse peripheral margin of the article in substantially straight lines to corner regions of the article. As illustrated in Fig. 1 of said document, the elastic means can be arranged so as to delimit a diamond- shaped central region on the absorbent core. Tension in the elastic means causes the transverse end regions of the article to be drawn together, thereby creating a "basin" which retains the discharged fluid. The arrangement according to EP-A-0 273 963 does not, however, provide particularly effective protection from lateral leakage.

SUMMARY OF THE INVENTION: It is therefore an object of the invention to provide an absorbent article such as a incontinence guard which is both effective against lateral leakage and lends itself to mass production techniques.

This object is achieved in accordance with the present invention by an absorbent article, such as a incontinence guard, having an absorbent core enclosed by a liquid- permeable topsheet and a liquid-impermeable backsheet, said topsheet and backsheet extending beyond said absorbent core to join together to form a peripheral margin extending around at least a portion of the absorbent core, said article having a longitudinal extension along, and being substantially symmetric about, a longitudinal axis, said article further comprising elastic means extending generally along said longitudinal extension, said article being characterized in that said elastic means define an outwardly convex curved path on either side of said longitudinal axis.

The term "outwardly convex curved path" is hereby defined as any continuous or interrupted path which extends in a non-linear manner from a first point in the vicinity of the longitudinal axis, outwardly from said first point to a second point further away from the longitudinal axis than the first point and then inwardly from the second point to a third point closer to the longitudinal axis than the second point.

Due to the outwardly convex curved path of the elastic means, the extent to which the side edges of the absorbent article are drawn upwardly can be easily provided for by altering, for example, the radius of curvature of the curved path.

Preferred embodiments of the invention are detailed in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS:

The invention will be described in the following in greater detail and with reference to the attached drawings, in which:

Fig. 1 is a plan view of a incontinence guard according to the present invention, and

Fig. 2 is a perspective view of the incontinence guard shown in Fig. 1 in a position adopted in use.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS: In the drawings, reference numeral 10 generally denotes an absorbent article according to the present invention. By way of example, the illustrated absorbent article is a incontinence guard.

The incontinence guard 10 comprises an absorbent core 12 enclosed by a liquid-permeable topsheet 14 and a liquid- impermeable backsheet 16. These sheets can be made of any suitable materials known in the art. The topsheet and backsheet overlie and extend beyond the absorbent core 12 to join together to form a peripheral margin 18 which preferably extends around the entire absorbent core.

The incontinence guard 10 is generally elongate and presents a longitudinal extension along, and is substantially symmetric about, a longitudinal axis 20. On either side of the longitudinal axis 20 there are arranged elastic means 22 which extend substantially the entire length of the napkin 10. In accordance with the present invention, each of the elastic means 22 defines an outwardly convex curved path on either side of the longitudinal axis 20. Preferably, the paths are symmetrically disposed about the longitudinal axis of the napkin 10. It has been shown to be advantageous if the outwardly curved paths present a mean radius of curvature R of between about 10% and 25%, preferably about 15 to 18%, of the longitudinal extension of the absorbent article.

The position of the elastic means 22 relative the absorbent core 12 along the length of the incontinence guard defines three zones or portions, i.e. a front portion 24, a mid portion 26 and a rear portion 28. The mid portion 26 is hereby defined as that portion of the article 10 through which the elastic means 22 extends along its outwardly convex curved path through only the peripheral margin 18. The front and rear portions 24, 28 resp. correspond to those portions either side of the mid portion 26 and through which the elastic means 22 extends over at least a part of the absorbent core 12. Thus, in the front and rear portions, the elastic means lies between the absorbent core 12 and the topsheet 14.

In the preferred illustrated embodiment of the invention, in order to impart the preferred "bowl" shape to the incontinence guard when in use, and as illustrated in Fig.

2, the longitudinal extension of the mid portion 26 is arranged to constitute at least 10% of the longitudinal extension of the incontinence guard 10. It is further advantageous if the paths of the elastic means on either side of the longitudinal axis 20 are spaced furthest apart in the mid portion 26. In this manner, the peripheral margin 18 within the mid portion 26 is caused to raise to thereby form lateral walls which hinder lateral leakage. Preferably, the mid portion constitutes between 15% and

75%, more preferably between 30% and 50%, of the longitudinal extension of the absorbent article.

The elastic means 22 are further arranged such that on each side of the longitudinal axis 20, the elastic means extends in a curved line from a point 30 on the front portion 24 in the vicinity of the peripheral margin 18, laterally across the front portion 24 to enter the peripheral margin 18 in the mid portion 26 and to cross into the rear portion 28 to extend towards the longitudinal axis 20 to terminate at a point 32 on the rear portion 28 in the vicinity of the peripheral margin 18. The point 30 on the front portion and the point 32 on the rear portion may be substantially equidistant from the longitudinal axis 20. This equidistance is advantageously between 5% and 10% of the longitudinal extension of the absorbent article.

Elasticity may be imparted on the article in any known manner. For example, the elastic means 22 may comprise one or more elastic threads or bands which extend on either side of the longitudinal axis 20. During manufacture, each thread or band is advantageously applied to the article in a tensioned condition, though it is of course conceivable that the elastic means be applied in a non-tensioned condition and thereafter treated, e.g. with heat or radiation, to impart elasticity. Preferably, the elastic threads or bands are attached to the surface of the topsheet 14 contacting the absorbent core 12, whilst the topsheet itself is advantageously affixed to the absorbent core at discrete locations.

The outwardly convex curved path of the elastic means implies that the elastic means imparts a force component in both the transverse direction and the longitudinal direction of the article. The transverse force component causes the peripheral margin 18 in the mid portion 26 to bend upwardly, i.e. in the direction of the topsheet 14, to thereby form a longitudinally extending liquid barrier. The force component in the longitudinal direction causes the article to adopt a curved form transverse to the longitudinal axis. So that the incontinence guard 10 adopts an optimal "bowl" shape when in its in use condition, it is advantageous if the front portion 24 constitutes between 10% and 50%, preferably between 25% and 30%, of the longitudinal extension of the article, whilst the rear portion constitutes between 10% and 70%, preferably between 30% and 50%, of the longitudinal extension.

To ensure that the absorbent article does in fact adopt a bowl shape, the article possesses a degree of rigidity in comparison with the tensioning force in the elastic means which is sufficient to prevent the article from merely crinkling up on itself in a non-definable manner. Thus, the rigidity may be present in any of the components of the article, either individually or in combination. Preferably, the article comprises a stiffening element, for example in the form of a heavily compressed absorption layer which may be of slightly lesser width than the remainder of the absorbent core 12. The stiffening element cooperates with the elastic means to provide the article with the desired bowl-shape, both in the longitudinal direction and the transverse direction. The extent of deformation in said directions is controlled by means, such as compressions, in the stiffening element.

The present invention is not restricted to the embodiment described above and illustrated in the drawings but may be varied within the scope of the appended claims. For example, whilst the invention has been described with particular reference to a incontinence guard, it will be evident to the skilled person that the invention may be suitably applied to any absorbent article, such as diapers, sanitary napkins or panty liners, in which it is desired to retain discharged fluid.

Claims

CLAIMS:

1. An absorbent article (10), such as a incontinence guard, having an absorbent core (12) enclosed by a liquid- permeable topsheet (14) and a liquid-impermeable backsheet (16), said topsheet and backsheet extending beyond said absorbent core to join together to form a peripheral margin (18) extending around at least a portion of the absorbent core (12), said article having a longitudinal extension along, and being substantially symmetric about, a longitudinal axis (20), said article further comprising elastic means (22) extending generally along said longitudinal extension, characterized in that said elastic means define an outwardly convex curved path on either side of said longitudinal axis (20).

2. The absorbent article as claimed in claim 1, characterized in that said article presents a front portion (24), a mid portion (26) and a rear portion (28), said mid portion (26) being defined by that portion of said article (10) through which said elastic means (22) extends along said outwardly convex curved path through only said peripheral margin (18), said front and rear portions (24, 28) being portions either side of said mid portion (26) through which said elastic means (22) extends over at least a part of said absorbent core (12), said mid portion (26) constituting at least 10% of said longitudinal extension of said absorbent article.

3. The absorbent article as claimed in claim 2, characterized in that said mid portion (26) constitutes between 15% and 75%, preferably between 30% and 50%, of said longitudinal extension of said absorbent article.

4. The absorbent article as claimed in any of the preceding claims, characterized in that said peripheral margin (18) extends around substantially the entire absorbent core (12).

5. The absorbent article as claimed in claim 4, characterized in that on each side of said longitudinal axis (20), said elastic means (22) extends from a point (30) on said front portion (24) in the vicinity of said peripheral margin (18), laterally across said front portion to enter said peripheral margin in said mid portion (26) and to cross into said rear portion (28) to extend towards said longitudinal axis to terminate at a point (32) on said rear portion (28) in the vicinity of said peripheral margin (18).

6. The absorbent article as claimed in any of the preceding claims, characterized in that said elastic means (22) comprises one or more elastic threads or bands on either side of said longitudinal axis (20).

7. The absorbent article as claimed in any of the preceding claims, characterized in that said front portion (24) constitutes between 10% and 50%, preferably between 25% and 30%, of said longitudinal extension of said absorbent article.

8. The absorbent article as claimed in any of the preceding claims, characterized in that said rear portion (28) constitutes between 10% and 70%, preferably between 30% and 50%, of said longitudinal extension of said absorbent article.

9. The absorbent article as claimed in any one of claims 5 to 8, characterized in that said point (30) on said front portion (24) and said point (32) on said rear portion (28) are substantially equidistant from said longitudinal axis (20).

10. The absorbent article as claimed in any one of claims 5 to 8, characterized in that the distance between said elastic means (22) on either side of said longitudinal axis (20) on said front portion (24) is different to the corresponding distance on said rear portion (28).

11. The absorbent article as claimed in any of the preceding claims, characterized in that said article (10) comprises a stiffening element.

12. The absorbent article as claimed in claim 11, characterized in that said stiffening element is in the form of a heavily compressed absorption layer.

13. The absorbent article as claimed in claim 11 or claim 12, characterized in that said stiffening element is provided with means for controlling the extent of deformation of the article (10) both along and transverse to said longitudinal axis (20).