AU2235800A - Sanitary absorbent article having tear-resistant flaps - Google Patents

Description

-1-

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: Actual Inventors: Address for Service: Invention Title: Johnson Johnson Inc Henri Brisebois and Jean-Sebastian Simard BALDWIN SHELSTON WATERS MARGARET STREET SYDNEY NSW 2000 'SANITARY ABSORBENT ARTICLE HAVING TEAR-RESISTANT

FLAPS'

The following statement is a full description of this invention, including the best method of performing it known to me/us:- File: 27454AUP00 1A SANITARY ABSORBENT ARTICLE HAVING TEAR-RESISTANT FLAPS FIELD OF THE INVENTION The present invention relates to sanitary absorbent articles such as feminaux sanitary napkins and incontinence pads, and, more particularly, to sanitary absorbent articles having at least one side-projecting flap that manifests a higher resistance to tearing when the sanitary absorbent article is removed from the undergarment with the flap still attached to the undergarment.

BACKGROUND OF THE INVENTION Sanitary absorbent articles generally are large-scale commercially manufactured articles used to absorb and retain bodily exudates. Such articles are convenient in that they are often economical yet disposable; they include sanitary napkins, infant diapers, adult incontinence pads and the like.

The technology surrounding sanitary absorbent articles, and particularly feminine sanitary napkins, has undergone several advances over the past two decades. One of such advances was the addition of a flap projecting laterally from each longitudinal side of the article when the article is in a flattened state. Such flaps may comprise integral extensions 20 of a material from which the article is formed or, alternatively, may simply comprise additional material added to the article after its formation.

When such articles are in use, the flaps are folded over the edges of the wearer's undergarment. They thus may more firmly secure the article to the undergarment, stabilize the article within the undergarment, provide an increased absorptive area for bodily exudates, and help prevent the undergarment from becoming soiled in part by protecting the side edges of the wearer's undergarment. The flap concept has generally met with success in the marketplace, and articles with flaps of various configurations and conformations are available to the consumer.

Conventional wisdom on the part of both designers and consumers has to date dictated that flaps on absorbent articles should be maximized at their line of juncture with the main body of the article in order to provide a greater area of protection against exudate leakage over the side of the article. Hence, a very common flap configuration is an isosceles bilaterally symmetrical) trapezoidal-shaped flap having its base adjoined with the longitudinal side of the main body of the article and projecting (and tapering) away therefrom to the top of the trapezoid. The size of the flap may vary from article to article.

The difficulty with absorbent articles of the trapezoidal and other conventional flap configurations is that the absorbent articles are designed and manufactured in a flat state, while in use the article should generally adopt a two- and often three-dimensional curvature in order to correctly interface with the body of the wearer. By two-dimensional curvature it is meant that the article will curve along one axis of the three-dimensional coordinate system formed by the longitudinal centre-line of the article, the transverse So centre-line of the article, and the line perpendicular to both. By three-dimensional 15 curvature it is meant that the article will curve along more than one axis of a threedimensional co-ordinate system (such a system having three orthogonal axes).

As an example, where the absorbent article is a feminine sanitary napkin, and is in use, a cross-section of the article in both the sagital plane of the wearer's body the longitudinal axis of the article) and the frontal or coronal plane of the wearer's body (i.e.

the transverse axis of the article) would most likely be curved. The flaps, however, are "'"°"generally designed to be folded about a linear folding axis commonly located along the line of juncture of the flap with the longitudinal side of the main body of the article. The difficulty with such a linear folding axis is that the edges of the wearer's undergarment, about which the flaps are folded, is curved. Moreover, the undergarment edges usually contain an elastic material for snugly securing the undergarment about the legs of the wearer. Depending on the force exerted by the elastic material, a curved shape may be imparted to the flaps and the central portion of the main body of the article causing them lift off the undergarment and wrinkle, or a flattened shape may be imparted to the edges of the undergarment causing them to not fit snugly against the legs of the wearer. In both cases, the comfort and efficiency of the article and its flaps are sacrificed. Moreover, the larger the flap, the more acute the problem. Thus while large flaps alleviate some difficulties on one hand side leakage protection), they create problems on the other instability and stress).

In order to alleviate the difficulties of conventional flap designs, a sanitary napkin has been proposed featuring flaps characterized by a width (dimension measured along the longitudinal axis of the sanitary napkin) that increases in a direction away from the main body of the napkin. This flap design offers a number of advantages, an important one being to securely retain the sanitary napkin to the undergarment of the wearer. Such enhanced retention is desirable because it stabilizes the sanitary napkin against the body of the wearer and thus reduces the likelihood of failure events.

It has been observed, however, that such strong attachment ability of the flaps may S: 15 cause the flaps to tear apart from the main body when the sanitary napkin is removed from the undergarment. Usually, the wearer will not detach the flaps from the undergarment before lifting away the main body. The tendency is to simply pull the main body while the flaps remain attached to the undergarment. This manipulation creates stress levels on the *sanitary napkin at the area of juncture main body/flap, often causing the flaps to tear and separate from the main body. This is undesirable since the wearer must then remove the separated flap(s) as a subsequent operation that may cause annoyance.

OBJECT AND STATEMENT OF THE INVENTION It is thus an object of the present invention to provide a sanitary absorbent article having an improved flap configuration, characterized by an ability to better resist tearing particularly when the sanitary absorbent article is removed from the undergarment with the flap still fastened to the undergarment.

As embodied and broadly described herein, the present invention provides a sanitary absorbent article comprising: a main body, said main body having a first longitudinal side, a second longitudinal side generally opposing the first longitudinal side, two generally opposing transverse sides, and a longitudinal centerline; a first flap united with said main body, said first flap projecting laterally from the first longitudinal side of said main body when the article is in a flattened state and being capable of being folded over a crotch portion of a wearer's undergarment, said first flap having; a) a distal side; b) a proximal side generally opposing the distal side of said first flap, the proximal side being adjacent to the first longitudinal side of said main body and connecting with the first longitudinal side of said main body along a line of juncture; c) a first transverse side; got* d) a second transverse side generally opposing the first transverse side of said first flap, the transverse sides of said first flap S .20 diverging in a direction away from said proximal side at least over a portion of their lengths; e) a fastener for retaining said first flap to the undergarment when said first flap is folded over a crotch portion of the undergarment; f) a distance between said first and second transverse sides measured at said line of juncture being at least about 45 mm; g) said absorbent article being characterized by a level of structural integrity preventing said flap from tearing away from said main body when said main body is pulled from the undergarment while said flap is still attached to the undergarment with a force sufficient to cause the flap to detach from the undergarment.

Preferably, the sanitary absorbent article further comprises a second flap united with said main body, said second flap being identical to the first flap.

It is preferred that the main body of the article be generally hourglass in shape with rounded ends. When the article is of such a conformation, the first and second transverse sides are the shorter opposing sides and will generally be arcuate. The first and second longitudinal sides are the longer opposing sides and will generally be biconcavely curved.

•It should be understood however that the shape of such sides is not essential to the invention, and thus the transverse or the longitudinal sides could be either arcuate or S straight.

S. For most articles, the longitudinal centerline thereof is an imaginary line that extends along the longitudinal axis of the article. Similarly, a flap centerline is an imaginary line that is perpendicular to the longitudinal centerline and passes on the flap.

20 It is preferred that the flaps be of a generally trapezoidal shape. For present purposes, when the flap is of such a shape, it should be considered that the "top" of the trapezoid is the shorter of the two generally parallel sides, and that the "base" of the "trapezoid is the longer of the two generally parallel sides. It should be understood that the term "generally parallel" is meant to encompass sides of a number of different conformations, including those which are slightly curved or angled and those which are formed from two or more straight edges joined at relatively wide angles.

Flaps of the present invention may comprise an integral extension of the materials (or some of the materials) of which the main body of the article is formed. As an example, the flaps may comprise extensions of the cover layer material and the barrier layer material which are joined together, typically about the periphery of the flap. They may also comprise flaps constructed from panels which themselves comprise integral extensions of the materials of which the main body of the article is formed, having been re-affixed to the underside of the main body on the garment facing-surface); all as described in commonly assigned co-pending International Patent Application PCTCA97/00990, filed December 22, 1997. Alternatively, the flaps may comprise additional material added to the main body of the article after the main body's formation, typically secured to the garment-facing surface of the main body.

It should be understood that flaps constructed in accordance with the teachings of the present invention could have a proximal length of varying dimensions. In one embodiment the flaps have lengths of 6.2 cm, however, flaps having lengths of less than "'"and greater than 6.2 cm 4.5, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15 cm) are all within it's the scope of the present invention. For clarity, the length of the proximal side of a flap S" is measured at the line of juncture between the flap and the main body.

The remaining two sides of the trapezoid form the first transverse side and second C..o transverse side of the flap. They are substantially divergent from the proximal side of the flap at least along a portion of their length.

Both the garment-facing surface of the main body and that of the flaps will typically include fasteners, such as adhesive fasteners that are used to secure the article to wearer's garments. Advantageously, each of the fasteners located on the garment-facing surfaces of each flap has a longitudinal length not less than about 75% of the length of the proximal side of the flap on which the fastener is located. In this context, the term "longitudinal length" should be understood as the maximum length of the fastener measured along a line parallel to the longitudinal centerline of the article. (For such purposes, gaps in the continuity of the fastener are ignored). The longitudinal length of the fastener may be colloquially termed its width. Longitudinal lengths of the fastener in the range from about 75 to about 115% of the length of the proximal side of the flap are possible.

In one possible embodiment, the geometrical shape of the flap is chosen so as to reduce the shear stress per unit area, particularly at the general area of juncture flap /main body when the main body is pulled away from the undergarment with the flap still attached to the undergarment. The geometrical shape of the flap is such as to define a ratio between distance A and distance B that is less than about 0.91, where distance A is the distance between the first transverse side and the flap centerline at an innermost point of the first transverse side relative the flap centerline, and distance B is the distance between the first transverse side and the flap centerline measured at the line of juncture. Preferably, the ratio does not exceed about 0.89. More preferably, the ratio does not exceed about 0.82.

Under this embodiment the shape of the transverse side, near the proximal side of the flap is a compound curve that is a combination of sectors of circles having different radii. More particularly, the transverse edge starts with a first sector of circle, S °15 followed by a second sector of circle. The first sector of circle has a radius of curvature that is substantially less than the radius of curvature of the second sector of circle. Also, the first sector of circle is concave, while the second one can be either concave or *o0° convex.

In a variant, the structural integrity of the flap may be increased to resist tearing by incorporating in the flap additional materials or stronger materials that will result in a I"°°"stronger flap. This will prevent the flap from tearing when the main body is pulled away from the undergarment with the flap still attached to the undergarment. Another possible variant is to reduce the level of retention that the fastener develops with the undergarment. When the fastener is an adhesive fastener, the formulation of the adhesive is controlled to reduce the level of bonding such that the flap will separate from the undergarment before the flap tears away from the main body.

Most preferably, the sanitary absorbent article is a feminine sanitary napkin, i.e. it is placed in the pudendal region of a female and is used to absorb menses and other discharged fluids.

8 Thus, as embodied and broadly described herein the invention also provides a sanitary absorbent article comprising: a main body, said main body having a first longitudinal side, a second longitudinal side generally opposing the first longitudinal side, two generally opposing transverse sides, and a longitudinal centerline; a first flap united with said main body, said first flap projecting laterally from the first longitudinal side of said main body when the article is in a flattened state and being capable of being folded over a crotch portion of a wearer's undergarment, said first flap having; a) a distal side; 6 b) a proximal side generally opposing the distal side of said first flap, the proximal side being adjacent to the first S. longitudinal side of said main body and connecting with 15 the first longitudinal side of said main body along a line of juncture; C.l. c) a first transverse side; d) a second transverse side generally opposing the first transverse side of said first flap, the transverse sides of 20 said first flap diverging in a direction away from said proximal side at least over a portion of their lengths; e) a first flap centerline that extends generally transversely to the longitudinal centerline of said main body; f) a ratio between distance A and distance B being less than about 0.89, where distance A is the shortest distance defined between said first transverse side and said flap centerline measured parallel to said line of juncture, and distance B is the distance between said first transverse side and said flap centerline at said line of juncture; g) a distance between said first and second transverse sides measured at said line of juncture being at least 45 mm.

As embodied and broadly described herein, the invention further provides a sanitary absorbent article comprising: a main body, said main body having a first longitudinal side, a second longitudinal side generally opposing the first longitudinal side, two generally opposing transverse sides, and a longitudinal centerline; a first flap united with said main body, said first flap projecting laterally from the first longitudinal side of said main body when the article is in a flattened state and being capable of being folded over a crotch portion of a wearer's undergarment, said first flap having; a distal side; a proximal side generally opposing the distal side of said first flap, the proximal side being adjacent to the first longitudinal side of said main body and connecting with the first longitudinal side of said main body along a line of juncture; c) a first transverse side; d) a second transverse side generally opposing the first transverse side of said first flap, the transverse sides of said first flap diverging in a direction away from said proximal side at least over a portion of their lengths; a first flap centerline that extends generally transversely to the longitudinal centerline of said main body; f) a fastener for retaining said second flap to the undergarment when said second flap is folded over a crotch portion of the undergarment; g) a distance between said first and second transverse sides measured at said line of juncture being at least 45 mm; h) said flap further characterized in that at least one transverse side includes a portion defining two sectors of circles, namely '0 a first sector and a second sector, the first sector characterized by a smaller radii that the second sector, and the first sector being closer to the proximal side than the second sector.

As embodied and broadly described herein, the invention also provides A sanitary absorbent article comprising: a main body, said main body having a first longitudinal side, a second longitudinal side generally opposing the first longitudinal side, two generally opposing transverse sides, and a longitudinal centerline; a first flap united with said main body, said first flap projecting laterally from the first longitudinal side of said main body when the article is in a S•"flattened state and being capable of being folded over a crotch portion of a wearer's undergarment, said first flap having; a) a distal side; b) a proximal side generally opposing the distal side of said first flap, the proximal side being adjacent to the first longitudinal side of said main body and connecting with the first longitudinal side of said main body along a line of juncture; a first transverse side; d) a second transverse side generally opposing the first transverse side of said first flap, the transverse sides of said first flap diverging in a direction away from said proximal side at least over a portion of their lengths; e) a first flap centerline that extends generally transversely to the longitudinal centerline of said main body; f) an adhesive fastener for retaining said second flap to the undergarment when said second flap is folded over a crotch portion of the undergarment, said adhesive fastener extending generally along the longitudinal centerline of said main body and including two generally opposite end portions; g) a distance between said first and second transverse sides measured at said line of juncture being at least 45 mm; 11 h) when said main body is pulled from the undergarment while said flap is still attached to the undergarment with a force sufficient to cause the flap to detach from the undergarment a tension vector being generated, said tension vector originating at an end portion of said fastener, said tension vector extending toward said main body and crossing said first transverse side at a certain location thereof; i) said flap being characterized in that a geometrical configuration of said first transverse side at said certain location is such as to prevent a shear stress level created by **said tension vector on said first transverse side to exceed a threshold at which said first flap begins tearing away from S. said main body.

15is Other objects and features of the invention will become apparent by reference to ao the following description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS A detailed description of preferred embodiments of the present invention is provided hereinbelow with reference to the following drawings, in which: Figure 1 is a top plan view of a feminine sanitary napkin; Figure la is a cross-sectional view of the napkin of Figure 1 taken along the line la la; Figure lb is an enlarged top plan view of the first flap of the napkin of Figure 1; Figure 2 is a bottom plan view of the napkin of Figure 1; Figure 2a is an enlarged bottom plan view of the first flap of the napkin of Figure lb; Figure 2b is an enlarged bottom plan view of the first flap of an alternative embodiment of the sanitary napkin, similar to Figure 2a; Figure 3 is an enlarged bottom plan view, similar to that of Figure 2a, of a first flap of a third embodiment of the sanitary napkin; 12 Figure 4 is a bottom plan view of the napkin of Figure 1 when placed within a typical undergarment; Figure 5 is a bottom plan view of a sanitary napkin in accordance with the present invention featuring flaps configured to manifest an increased resistance to tearing; Figure 6 is a fragmentary enlarged view of the flap area of the sanitary napkin of Figure 5 illustrating the flap configuration designed to increase the resistance to tearing; Figure 7 is an enlarged view of a transverse side of a flap of a second embodiment of the sanitary napkin of Figure 5 with a flap configuration designed to increase the resistance to tearing; Figure 8 is a fragmentary enlarged view of the flap area of a third embodiment i oeO the sanitary napkin of Figure 5 with a flap configuration designed to increase the resistance to tearing; and Figures 9a, 9b and 9c are top plan views of the flaps of the three embodiments 15 of the sanitary napkin of Figure 5 shown in Figures 6, 7 and 8, respectively.

In the drawings, preferred embodiments of the invention are illustrated by way of example. It is to be expressly understood that the description and drawings are only for purposes of illustration and as aids to understanding, and are not intended to be a definition of the limits of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Figure 1 illustrates a feminine sanitary napkin 20. The napkin is of a laminate construction and comprises a fluid-permeable cover layer 22, an absorbent system 24, and a fluid-impervious barrier layer 13 Cover Layer The cover layer 22 may be a relatively low density, bulky, high-loft non-woven web material. The cover layer 22 may be composed of only one type of fibre, such as polyester or polypropylene or it may be composed of bi-component or conjugate fibres having a low melting point component and a high melting point component. The fibres may be selected from a variety of natural and synthetic materials such as nylon, polyester, rayon (in combination with other fibres), cotton acrylic fibre and the like and combinations thereof.

Bi-component fibres may be made up of a polyester core and a polyethylene sheath. The use of appropriate bi-component materials results in a fusible non-woven o. fabric. Examples of such fusible fabrics are described in U.S. Patent 4,555,430 issued November 26, 1985 to Mays. Using a fusible fabric increases the ease with which the cover layer may be mounted to the adjacent transfer layer and/or to the barrier layer.

o The cover layer 22 preferably has a relatively high degree of wettability, although the individual fibres comprising the cover may not be particularly hydrophilic. The cover material should also contain a great number of relatively large pores. This is because the cover layer 22 is intended to absorb body fluid rapidly and transport it away from the body and the point of deposition. Preferably, the fibres which make up the cover layer 22 should not lose their physical properties when they are wetted, in other words, they should not collapse or lose their resiliency when subjected to water or body fluid. The cover layer 22 may be treated to allow fluid to pass through it readily. The cover layer 22 also functions to transfer the fluid quickly to the other layers of the absorbent structure 24. Thus, the cover layer 22 is preferably wettable, hydrophilic and porous. When composed of synthetic hydrophobic fibres such as polyester or bi-component fibres, the cover layer 22 may be treated with a surfactant to impart the desired degree of wettability.

Most preferably, the cover layer 22 is made of polymer film having large pores.

Because of such high porosity, the film accomplishes the function of quickly transferring body fluid to the inner layers of the absorbent system. Apertured co-extruded films such as 14 RETICULON~r brand, for example, described in U.S. Patent 4,690,679 are useful as cover layers in the absorbent structures of this invention.

The cover layer 22 may be embossed to the remainder of the absorbent system 24 in order to aid in promoting hydrophilicity by fusing the cover to the next layer.

Absorbent System Transfer Laye Adjacent to the cover layer 22 on its inner side and bonded to the cover layer 22 is a fluid transfer layer 26 that forms part of the absorbent system 24. The transfer layer 26 provides the means of receiving body fluid from the cover layer 22 and holding it until the ~.highly-dense absorbent core 28 has an opportunity to absorb the fluid.

0. The transfer layer 26 is, preferably, more dense than and has a larger proportion of *smaller pores than the cover layer 22. These attributes allow the transfer layer 26 to contain body fluid and hold it away from the outer side of the cover layer 22, thereby preventing the fluid from re-wetting the cover layer 22 and its surface. However, the transfer layer 26 is, preferably, not so dense as to prevent the passage of the fluid through *the layer 26 into the absorbent core 2 8 The transfer layer 26 may be composed of fibrous materials, such as wood pulp, 0 polyester, rayon, flexible foamn, or the like, or combinations thereof. The transfer layer 26 may also comprise thermoplastic fibers for the purpose of stabilizing the layer and maintaining its structural integrity. The transfer layer 26 may be treated with surfactant on one or both sides in order to increase its wettability, although generally the transfer layer 26 is relatively hydrophilic and may not require treatment. The transfer layer 26 is preferably bonded on both sides to the adjacent layers, i.e. the cover layer 22 and the absorbent core 28.

Abobn ytm-AsretCr Immediately adjacent to and bonded to the transfer layer 26 is the absorbent core 28. The absorbent core 28 is preferably a highly dense layer having a fine porosity. It has a large liquid holding capacity and it is extremely retentive. The absorbent core 28 may include compressed sphagnum moss material. More specifically, the sphagnum moss is formed as a board by air or wet laying and calendering to obtain a relatively thin, i.e. from about 0.025 cm to 0.25 cm thick, relatively dense, i.e. from about 0.2 to i.0 g/cm 3 sheetlike structure. The structure may include a layer of Kraft tissue laminated on one or both surfaces of the sphagnum moss layer. Preferably, a fibrous component is admixed with the sphagnum moss material. The fibrous component is suitably a natural or synthetic textile fiber such as rayon, polyester, nylon, acrylic or the like, having a length of from about 0.62 to 3.75 cm and a denier of from about 1.0 to 5. The fibrous component may be present in an amount from about 2 to 20% by weight, most preferably from 4 to The absorbent core 28 may also comprise other components such as wood pulp, synthetic wood pulp, *....thermo-mechanical pulp, mechanically ground pulp, polymers, surfactants, superabsorbents and the like.

In an alternative embodiment, the absorbent system 24 includes a single layer of pulp fluff material (the transfer layer is omitted). The absorbent core 28 preferably comprises a pulp fluff material and may optionally include other absorbent materials or non-absorbent materials which aid in stabilizing the absorbent structure such as conjugate S fibers, fusible fibers, binders, sphagnum peat moss particles, superabsorbents, and the like and combinations thereof, and may optionally include other absorbent materials or nonabsorbent materials which aid in stabilizing the absorbent structure such as conjugate o ~fibers, fusible fibers, binders, sphagnum peat moss particles, superabsorbents, and the like and combinations thereof.

Barrier Layer Underlying the absorbent system 24 is a barrier layer 30 comprising fluidimpervious film material so as to prevent liquid that is entrapped in the absorbent core from egressing the sanitary napkin and staining the wearer's undergarment. Most preferably, the barrier layer 30 is made of polymeric film, such as polyethylene that is both inexpensive and readily available. The polyethylene is capable of fully blocking the 16 passage of liquid or gas that may emanate from the absorbent system 24. In a variant, breathable films may be used that allow passage of gases while blocking liquid.

The cover layer 22 and the barrier layer 30 are joined along their marginal portions so as to form an enclosure that maintains the absorbent system 24 captive. The joint may be made by means of adhesives, heat-bonding, ultrasonic bonding, radio frequency sealing, mechanical crimping, and the like and combinations thereof. The peripheral seal line is shown in Figure 1 by the reference numeral 92.

Flap Configuration Referring again to Figure 1 and Figurelb, the sanitary napkin 20 is comprised of a main body 21 having a first transverse side 36 and an opposing second transverse side 38.

Each transverse side 36, 38 is arcuate in shape (curved outward such that the two transverse sides 36, 38 are biconvex), with no particular curvature being essential to the present invention. The sanitary napkin 20 further has a generally arcuate first longitudinal side 40 and an opposing generally arcuate second longitudinal side 42, each being curved inward the longitudinal sides 40, 42 are biconcave), with no particular curvature being essential to the present invention. The shape of the main body 21 of the napkin 20 when viewed from above, as shown in Figure 1, is thus somewhat hourglass-like. The contour of the sanitary napkin 20 is symmetric about an imaginary longitudinal centerline extending longitudinally down the sanitary napkin 20, and a transverse centerline 47 extending transversely across the napkin A first flap 44 projects laterally from the central region of first longitudinal side of the main body 21. The first flap 44 is generally of the shape of an isosceles (i.e.

bilaterally symmetrical) trapezoid. The first flap 44 thus has a distal end 52 formed of the base of the trapezoid. The distal end 52 is preferably slightly convexo-arcuate. The sides of the trapezoid include a first transverse side 48 and second transverse side 50 of the first flap 44. The top of the trapezoid forms the proximate side 59 of the first flap 44. As the first flap 44 is formed from an integral extension of the cover layer 22 and the barrier layer 17 of the main body 21, the proximate side 59 of the first flap 44 adjoins the first longitudinal side 40 of the main body 21 of the napkin The first transverse side 48 of the first flap 44 intersects the distal side 52 of the first flap 44 at a (first) point of intersection 54. Similarly, the second transverse side 50 of the first flap 44 intersects the distal side 52 of the first flap 44 at a (second) point of intersection 56. A first (imaginary) line 58 may be drawn between these points of intersection 54, 56. (The length of this line being illustrated by reference number 58a., and is approximately 7.0 cm) The first transverse Side 48 of the first flap 44 intersects the first longitudinal side 40 of the main body 21 at (third) point of intersection 61. Similarly, the second transverse side 50 of the first flap 44 intersects the first longitudinal side 40 of the main body 21 at a (fourth) point of intersection 63. A second (imaginary) line .i (representing the proximal side 59) may be drawn between these points of intersection 61, 63. The length of this line being illustrated by reference number 60a, and is approximately 15 6.2 cm. The line 60 is the line of juncture between the flap and the main body. In this oooo example, the points of intersection 61 and 63 are located at the end of the curves that merge the proximal sides of the flap with the longitudinal edge of the main body. Figure lb illustrates this feature. The length 58a of the first line 58 is greater than the length of the second line (line of juncture) The first flap 44 has a midpoint 57 which is equidistant from the first imaginary line 58 and the second imaginary line 60 while at the same time being equidistant from the first transverse side 48 and the second transverse side 50 of the first flap 44. An imaginary line 55 parallel to the longitudinal centerline 50 may be drawn through the midpoint 57.

A second flap 46 projects laterally form the central region of the second longitudinal side 42 of the main body 21. The second flap 46 is generally of the shape of an isosceles trapezoid. The second flap 46 thus has a distal end 70 formed of the base of the trapezoid. The distal end 70 is preferably slightly convexo-arcuate. The sides of the trapezoid include a first transverse side 66 and the second transverse side 68 of the second flap 46. The top of the trapezoid forms the proximate side 77 of the 18 second flap 46. As the second flap 46 is formed from an integral extension of the cover layer 22 and the barrier layer 30 of the main body 21, the proximate side 77 of the second flap 46 adjoins the second longitudinal side 42 of the main body 21 of the napkin The first transverse side 66 of the second flap 46 intersects the distal side 77 of the second flap 46 at a (first) point of intersection 72. Similarly, the second transverse side 68 of the second flap 46 intersects the distal side 70 of the second flap 46 at a (second) point of intersection 74. A first (imaginary) line (not shown) may be drawn between these points of intersection 72, 74. (The length of this line is illustrated by reference number 76a, and is approximately 7.0 cm) The first transverse side 66 of the second flap 46 intersects the second longitudinal side 42 of the main body 21 at a (third) point of intersection 79. Similarly, the second transverse side 68 of the second flap 46 intersects the second longitudinal side 42 of the main body 21 at a (fourth) point of intersection 81.

A second imaginary line of juncture (not shown) may be drawn between these points of intersection 79, 81. The length of this line is illustrated by reference number 78a and is approximately 6.2 cm. The length 76a of the first line is greater than the length 78a of the o..second line.

The second flap 46 has a midpoint (not shown) which is equidistant from the first imaginary line and the second imaginary line while at the same time being equidistant from the first transverse side 66 and the second transverse side 68 of the second flap 46.

Figures 5 to 9c illustrate in greater detail the structure of the flaps of the sanitary napkin designed to reduce the likelihood of tearing at the corners of the flaps near the longitudinal edges of the main body when the sanitary napkin is removed from the undergarment with the flaps still attached to the undergarment.

With reference to Figure 5, the first transverse side 48 of the flap 44 intersects the distal side 52 of the flap 44 at the point of intersection 54. The first transverse side 48 of the flap 44 intersects the first longitudinal side 25 of the main body 21 at the point 19 of intersection 61 which is located along the line of juncture 60 coinciding with the proximate side 59 of the flap 44. When an imaginary line 500 is drawn between the points of intersection 61 and the outermost part 54 of the flap 44 relative the centerline 506 of the flap 44, an area is defined between the imaginary line 500 and the transverse side 48 of the flap 44. This area has a maximum dimension 502 that is measured along the centerline 504 of the main body 21. Preferably, the maximum dimension 502 is at least 3 mm. More preferably, this maximum dimension is in the range from about 4 mm to about 7 mm and most preferably from about 4.5 mm to about 6.5 mm In the embodiment shown in Figures 5 and 6, the maximum dimension 502 is about 4.7 mm.

The following tables provide the depths of the transverse side 48 from the imaginary line 500 function of the distances from the point of intersection 61 for the napkin flap illustrated in Figure 6 and the variant shown in Figure 7.

15 Table 1: Distances and Depths for the Flap Configuration in Figure 6 S1 2 3 4.2 4 4.7 6 4.6 7 4.2 8 3.7 9 3.2 2.8 11 2.4 Table 2: Distances and Depths for the Flap Configuration in Figure 7 'a

S

S.

*0 5

S

Jo

S

S

S

S

See.

@0 0 1 2 3.6 3 4.4 4 5 5.4 6 5.7 7 5.9 8 9 5.9 10 5.7 11 5.3 12. 4.8 13 14 3.2 2.6 16 Referring to Figure 6 the shape of the transverse side 48, near the proximal side of the flap is a compound curve that is a combination of sectors of circles having different radii. More particularly, the transverse edge starts with a first sector of circle contained between the point of intersection 61 and a mark at 7.0 mm from the point of intersection. This sector of a circle has a radius of about 4.6 mm and an angle spread of 116.3 degrees. A second sector of circle is bounded between the mark at 7.0 mm and a 21 mark at 17.9 mm. This sector of circle has a radius of about 40 mm and a angle spread of 17.2 degrees. The radius of the first sector of circle is substantially less than the radius of the second sector. Also, the first sector of circle is concave, while the second one is convex.

Now referring to Figure 7 it will be noted that the shape of the transverse side 48 is also compound curve that is a combination of three sectors of circles having different radii. More particularly, the transverse edge starts with a first sector of circle contained between the point of intersection 61 and the mark at 1.6 mm from the point of S* •10 intersection 61. This sector of a circle has a radius of about 4.6 mm and an angle spread of 51.1 degrees. A second sector of circle is bounded between the mark at 1.6 mm and the mark at 12.8 mm. This sector of circle has a radius of about 8.2 mm and an angle spread of 86.5 degrees. A third sector of a circle is defined between the mark at 12.8 mm and the mark at 22.4 mm. This third sector of a circle has a radius of 20 mm and an 9o* 15 angle spread of 31.9 degrees. The first and the second sectors of circle are concave while the third one is convex.

Figure 8 is an enlarged view of a flap and a portion of the main body of a third 20 embodiment of the sanitary napkin shown in Figure 5. As may be seen from Figure 8, the main body 21 of the napkin has a longitudinal centerline 504. The flap 44 has a distal side 52, a first transverse side 48 and a proximate side 59. The proximate side 59 of the flap 44 is attached to the main body 21 of the sanitary napkin along the line of juncture 60 which extends longitudinal along the main body 21 of the napkin and is generally parallel to the centerline 504. The flap has a centerline 506 that extends generally transversely to the centerline 504 of the napkin.

An imaginary line 508 having a length A connects the innermost point of the first transverse side 48 relative the centerline 506 of the flap. In the example shown, the innermost point is the location corresponding to the shortest distance from the centerline 506 to the transverse side 48, the distance being measured parallel to the line of juncture Similarly, an imaginary line 510 having a length B extends from the first transverse 22 side 48 to the centerline of the flap 506. In the example shown, the imaginary line 510 coincides with the line of juncture Figure 8 also illustrates in greater detail the geometrical configuration of the transverse side 48 of the flap 44. The transverse side 48 of the flap 44 includes a portion that is adjacent to the main body and which is comprised of two sectors of circle, namely a first segment merging the transverse edge with the longitudinal side edge of the main body and a second segment. The first segment has a radius of curvature of 2.54 mm and has an angular extent of about 73.647 degrees. The second segment has a radius of curvature of 14 mm and has an angular extent of 52.376 degrees. Both segments are concave.

0. 1.

In the embodiment of the sanitary napkin flap shown in Figure 8, the ratio A/B is about 0.91. In the embodiment of Figure 6 the ratio is about 0.87. In the embodiment of Figure 7 the ratio is about 0.82. The sanitary napkin flaps of Figures 6, 7 and 8 are illustrated with their actual lengths A and B in Figures 9a, 9b and 9c, respectively.

The flap configuration illustrated in Figure 8 is symmetrical about the flap 20 centerline 506. This is not an essential feature of the invention as only one of the transversal side of the flap can be provided with the geometrical configuration to achieve the improved resistance to tearing.

Adhesive Fasteners Referring to Figure 2, in order to enhance the stability of the sanitary napkin 20, on the garment-facing side 85 of the barrier layer 30 of the main body 21, there are provided five fasteners 83, 86, 88, 94, 98 for fastening the napkin 20 to the undergarment 18 of a wearer when the napkin 20 is in use. Each of these fasteners 83, 86, 88, 94, 98 are of a conventional design e.g. they comprise adhesive material, such as hot-melt adhesives capable of establishing a temporary bond with the undergarment 18 material. One 88 of these fasteners is located in the central region of the main body 21 of the napkin 20, a 23 second 94 and third 98 in the area of the transverse sides 38, 38 of the main body 21 of the napkin 20, and a fourth 83 and a fifth 86 in the area of the distal edge 52, 70 of the first flap 44 and second flap 46, respectively. Separate release papers 96, 99 cover the second 94 and the third 98 fasteners, while a single release paper 84 covers the first 88, fourth 83, and fifth 86.

Referring to Figure2a, there is shown the garment-facing surface 85 of the first flap 44 shown in Figure lb, including the fourth adhesive 83. (The release paper 84 having been removed.) The adhesive has been applied in a generally rectangular shape, the longer 10 side 83a of which is parallel to the longitudinal centerline of the article 20. The fourth adhesive 83 has a width 83w measurement taken in a direction parallel to the transverse centerline of the article) of 1.5 cm and a length 831 measurement taken in a direction parallel to the longitudinal centerline of the article) of 4.8 cm. Although not shown, the fifth adhesive 86 would be of similar construction.

Alternate Embodiments i" Referring to Figure 2b, there is shown a garment-facing surface 285 of a flap 244 (similar to that shown in Figure 2a) having an alternate embodiment. Specifically the "fourth" adhesive 283 has been applied in a discontinuous fashion, i.e. there are gaps 201a, 201b, 201c, 201d, in the continuity of the adhesive 283. The adhesive 283 now takes the appearance of a plurality of rectangles 203a, 203b, 203c, 203d, and 203e. The center rectangle 203c has a width 203w of 1.5 cm and a 203cl length of 1.6 cm. Each of the other rectangles 203a, 203b, 203d, 203e (there are two are on either side of the central one) having a width 203w of 1.5 cm and a length 203al, 203 bl, 203dl, 203el respectively, of cm. The rectangles 203a, 203b, 203c, 203d, 203e each are being separated by a distance of 0.3 cm. The purpose of these gaps 201a, 201b, 201c, 201d is to reduce the adhesive strength of the adhesive 283 in the areas closer to the transverse sides 248, 250 of the flap 244. The adhesive 283 itself is otherwise the same as described hereinabove in reference to Figure 2a. Similarly, although not shown, a "fifth" adhesive would be of similar construction.

24 Referring to Figure 3, there is shown another embodiment of the present invention.

In this embodiment the "fourth" fastener 383, i.e. that on the first flap 344, has a longitudinal length 390a which exceeds the length 360a of the second line 360 (representing the proximal side) on the first flap 344. Moreover, the transverse sides 348 and 350 are only substantially straight between their respective points of intersection 361, 363 with the proximal side 359 and their respective points of intersection 391a, 391b with the line 391 along which the longitudinal length 390 of the adhesive 383 is measured.

Similarly, although not shown, a "fifth" adhesive would be of similar construction.

The flap configurations depicted in greater detail in Figures 5, 6, 7, 8, 9a, 9b and 9c manifest a higher resistance to tearing because the shape of the transverse sides of the flaps are such as to reduce the level of stress created at the general area of the juncture flap /main body when the main body is pulled from the undergarment with the flaps still attached to the undergarment. Without intent of being bound by a specific I15 theory, when the main body of the sanitary napkin is pulled away from the undergarment with the flaps still attached to the undergarment, tension vectors are created originating at the longitudinal ends of each adhesive fastener and extending toward the main body. With flaps shaped such that the transverse sides diverge at least along a portion of their length, such tension vectors cross the respective transverse 20 sides. The flaps that have the characteristics described above resist tearing because the geometrical configuration of the transverse sides allows reducing the level of shear stress that the tension vectors create on the transverse sides. As a result, there is a lesser degree of risk that the flaps will tear. More specifically, the geometrical configuration of each transverse side, at the location thereof that contains the tension vector, is such as to prevent the shear stress level created by the tension vector and acting on the transverse side to exceed a threshold at which said first flap begins tearing away from said main body. Such tearing would arise as a result of a fissure propagation phenomenon in the material of the flap. The likelihood of a fissure propagating though the material of the flap and resulting in a partial or a complete tearing of the flap from the main body is directly related to the level of shear stress created by the tension vector on the transverse side of the flap. The geometrical configuration of the flap in the area where the tension vector crosses the transverse side of the flap controls the level of shear stress in that area. In the examples given earlier, the geometrical configuration is a sector of a circle that is concave.

In a possible variant, such resistance to tearing can be obtained by increasing the structural integrity of the flaps, without necessarily shaping the transverse sides of the flaps as described earlier. This can be accomplished by using stronger materials or by using additional materials in the flaps. Yet another possibility is to use a fastener that has a reduced bonding strength with the. In the case of an adhesive fastener, the formulation of the fastener or the amount of the adhesive material can be controlled to reduce the bonding level beyond the threshold at which the flaps tear from the main :body. This allows pulling the main body from the undergarment until the flaps separate from the undergarment and such separation occurs before the flaps tear away from the main body.

The above description of preferred embodiments should not be interpreted in a limiting manner since other variations, modifications and refinements are possible within the spirit and scope of the present invention. The scope of the invention is defined in the "20 appended claims and their equivalents.

Claims (27)

1. A sanitary absorbent article comprising: a main body, said main body having a first longitudinal side, a second longitudinal side generally opposing the first longitudinal side, two generally opposing transverse sides, and a longitudinal centerline; a first flap united with said main body, said first flap projecting laterally from the first longitudinal side of said main body when the article is in a flattened state and being capable of being folded over a crotch portion of a wearer's undergarment, said first flap having; a) a distal side; b) a proximal side generally opposing the distal side of said first flap, the proximal side being adjacent to the first longitudinal side of said main body and connecting with the first longitudinal side 15 of said main body along a line of juncture; eeo. c) a first transverse side; d) a second transverse side generally opposing the first transverse side of said first flap, the transverse sides of said first flap diverging in a direction away from said proximal side at least 20 over a portion of their lengths; S• e) a first flap centerline that extends generally transversely to the longitudinal centerline of said main body; and f) a-ratio between distance A and distance B being less than about 0.91, where distance A is the shortest distance defined between said first transverse side and said flap centerline measured parallel to said line of juncture, and distance B is the distance between said first transverse side and said flap centerline at said line of juncture; g) a distance between said first and second transverse sides measured at said line of juncture being at least 45 mm.

2. A sanitary absorbent article as recited in claim 1, further comprising: 27 a second flap united with said main body, said second flap projecting laterally from the second longitudinal side of said main body when the article is in a flattened state and being capable of being folded over the crotch portion of the undergarment, said second flap having; a) a distal side; b) a proximal side generally opposing the distal side of said second flap, the proximal side of the second flap being adjacent to the second longitudinal side of said main body and connecting with the second longitudinal side of said main body along a line of juncture associated with said second flap; c) a first transverse side; S. d) a second transverse side generally opposing the first transverse S"side of said second flap, the transverse sides of said second flap diverging in a direction away from said proximal side at least 15 over a portion of their lengths; e) a second flap centerline that extends generally transversely to the longitudinal centerline of said main body; and f) a ratio between distance C and distance D being less than about 0.91, where distance C is the shortest distance defined between 20 the first transverse side of said second flap and said second flap centerline measured parallel to the line of juncture associated with said second flap, and distance D is the distance between the first transverse side of said second flap and said second flap centerline at the line of juncture associated with said second flap; g) a distance between the first and second transverse sides of said second flap measured at said line of juncture being at least mm.

3. A sanitary absorbent article as recited in claim 1, wherein the ratio A/B does not exceed about 0.87

4. A sanitary absorbent article as recited in claim 1, wherein the ratio A/B does not exceed about 0.82.

5. A sanitary absorbent article as recited in claim 1, wherein the distance between the first and second transverse sides of said first flap measured at said line of juncture being at least about 62 mm.

6. A sanitary absorbent article as recited in claim 7, wherein the fastener of said first 10 flap and the fastener of said second flap are adhesive fasteners.

7. A sanitary absorbent article as defined in claim 1, wherein said sanitary absorbent 4 article is a sanitary napkin.

8. A sanitary absorbent article comprising: a main body, said main body having a first longitudinal side, a second longitudinal side generally opposing the first longitudinal side, two generally opposing transverse sides, and a longitudinal centerline; a first flap united with said main body, said first flap projecting laterally oo.. from the first longitudinal side of said main body when the article is in a flattened state and being capable of being folded over a crotch portion of a wearer's undergarment, said first flap having; a) a distal side; b) a proximal side generally opposing the distal side of said first flap, the proximal side being adjacent to the first longitudinal side of said main body and connecting with the first longitudinal side of said main body along a line of juncture; c) a first transverse side; d) a second transverse side generally opposing the first transverse side of said first flap, the transverse sides of said first flap p p. S p p S 29 diverging in a direction away from said proximal side at least over a portion of their lengths; e) a fastener for retaining said first flap to the undergarment when said first flap is folded over a crotch portion of the undergarment; a distance between said first and second transverse sides measured at said line of juncture being at least 45 mm; h) said absorbent article being characterized by a level of structural integrity preventing said flap from tearing away from said main body when said main body is pulled from the undergarment while said flap is still attached to the undergarment with a force sufficient to cause the flap to detach from the undergarment.

9. A sanitary absorbent article as recited in claim 8, further comprising a second flap united with said main body, said second flap projecting laterally from the first longitudinal side of said main body when the article is in a flattened state and being capable of being folded over a crotch portion of a wearer's undergarment, said second flap having; a) a distal side; b) a proximal side generally opposing the distal side of said second flap, the proximal side of said second flap being adjacent to the second longitudinal side of said main body and connecting with the second longitudinal side of said main body along a line of juncture associated with said second flap; c) a first transverse side; d) a second transverse side generally opposing the first transverse side of said second flap, the transverse sides of said second flap diverging in a direction away from the proximal side of said second flap at least over a portion of their lengths; L C e) a fastener for retaining said second flap to the undergarment when said second flap is folded over a crotch portion of the undergarment; f) a distance between the first and second transverse sides of said second flap measured at the line of juncture associated with said second flap being at least 45 mm; i) said absorbent article being characterized by a level of structural integrity preventing said second flap from tearing away from said main body when said main body is pulled from the undergarment while said flap is still attached to the undergarment with a force -sufficient to cause the flap to detach from the undergarment. S. 15

10. A sanitary absorbent article as recited in claim 9, wherein the distance between the otto first and second transverse sides of said first flap measured at said line of juncture being at least about 62 mm. se e

11. A sanitary absorbent article as recited in any one of claim 9 and claim 10 wherein the fastener of said first flap and the fastener of said second flap are adhesive fasteners.

12. A sanitary absorbent article as defined in claim 10, wherein said sanitary absorbent article is a sanitary napkin.

13. A sanitary absorbent article comprising: a main body, said main body having a first longitudinal side, a second longitudinal side generally opposing the first longitudinal side, two generally opposing transverse sides, and a longitudinal centerline; a first flap united with said main body, said first flap projecting laterally from the first longitudinal side of said main body when the article is in a 31 flattened state and being capable of being folded over a crotch portion of a wearer's undergarment, said first flap having; a) a distal side; b) a proximal side generally opposing the distal side of said first flap, the proximal side being adjacent to the first longitudinal side of said main body and connecting with the first longitudinal side of said main body along a line of juncture; c) a first transverse side; go.. d) a second transverse side generally opposing the first 10 transverse side of said first flap, the transverse sides of said first flap diverging in a direction away from said proximal side at least over a portion of their lengths; e) a first flap centerline that extends generally transversely to the longitudinal centerline of said main body; 15 f) a fastener for retaining said second flap to the undergarment when said second flap is folded over a crotch portion of the undergarment; g) a distance between said first and second transverse sides measured at said line of juncture being at least 45 mm; h) said flap further characterized in that at least one transverse side includes a portion defining two sectors of circles, namely a first sector and a second sector, the first sector characterized by a smaller radii that the second sector, and the first sector being closer to the proximal side than the second sector.

14. A sanitary absorbent article as recited in claim 15, further comprising a second flap united with said main body, said second flap projecting laterally from the second longitudinal side of said main body when the article is in a flattened state and being capable of being folded over a crotch portion of a wearer's undergarment, said second flap having; a) a distal side; p I 32 b) a proximal side generally opposing the distal side of said second flap, the proximal side of said second flap being adjacent to the second longitudinal side of said main body and connecting with the second longitudinal side of said main body along a line of juncture associated with said second flap; c) a first transverse side; d) a second transverse side generally opposing the first transverse side of said first flap, the transverse sides of said first flap diverging in a direction away from the proximal side of said second flap at least over a portion of their lengths; e) a second flap centerline that extends generally transversely to the longitudinal centerline of said main body; f) a fastener for retaining said second flap to the undergarment when said second flap is folded over a crotch portion of the .D undergarment; g) a distance between the first and second transverse sides of said second flap measured at the line of juncture associated with said second flap being at least 45 mm; h) said second flap further characterized in that at least one transverse side of the second flap includes a portion defining two sectors of circles, namely a first sector associated with said second flap and a second sector associated with said second flap, the first sector associated with said second flap characterized by a smaller radii than the second sector associated with said second flap, and the first sector associated with said second flap being closer to the proximal side than the second sector associated with said second flap.

A sanitary absorbent article as recited in claim 14, wherein the distance between the first and second transverse sides of said first flap measured at said line of juncture being at least 62 mm. y I 33

16. A sanitary absorbent article as recited in any one of claims 14 and 15, wherein the fastener of said first flap and the fastener of said second flap are adhesive fasteners.

17. A sanitary absorbent article as defined in claim 16, wherein said sanitary absorbent article is a sanitary napkin.

18. A sanitary absorbent article as defined in claim 14, wherein said first and said 10 second sectors of circle are concave. .i

19. A sanitary absorbent article as defined in claim 14, wherein said first sector of circle .i is concave and said second sector of circle is convex.

20. A sanitary absorbent article as defined in claim 14, wherein said at least one transverse side defines a third sector of circle having a radius larger than the radius of said second sector of circle. 2 19. A sanitary absorbent article as defined in claim 14, wherein said first sector of circle 20 merges with the first lsecongitud sector of circlde ede of said main body.convex. 20. A sanitary absorbent article comprias defing:ed in claim 14, wherein said at least one Sa main body, said main body having a first longitudinal side, a second longitudinal side generally opposing the first longitudinal side, two 25 generally opposing transverse sides, and a lovingtu a radius largl cer than the "•"radius of said second sector of circle. •o

21. A sanitary absorbent flap united with said ain bodyclaim 14, wherein said first flap projectngor of crlerally merges withom the first longitudinal side edge of said main body when the article is in a o

22. A sanitary absorbent article comprising: a main body, said main body having a first longitudinal side, a second longitudinal side generally opposing the first longitudinal side, two generally opposing transverse sides, and a longitudinal centerline; a first flap united with said main body, said first flap projecting laterally from the first longitudinal side of said main body when the article is in a flattened state and being capable of being folded over a crotch portion of a wearer's undergarment, said first flap having; j) a distal side; i 0t 34 k) a proximal side generally opposing the distal side of said first Sflap, the proximal side being adjacent to the first longitudinal side of said main body and connecting with the first longitudinal side of said main body along a line of juncture; s 1) a first transverse side; m) a second transverse side generally opposing the first transverse side of said first flap, the transverse sides of said first flap diverging in a direction away from said proximal a goside at least over a portion of their lengths; 0 n) a first flap centerline that extends generally transversely to !""1the longitudinal centerline of said main body; S• o) an adhesive fastener for retaining said second flap to the o• undergarment when said second flap is folded over a crotch egg portion of the undergarment, said adhesive fastener extending So.. S 15 generally along the longitudinal centerline of said main body and including two generally opposite end portions; 5 p) a distance between said first and second transverse sides measured at said line of juncture being at least 45 mm; when said main body is pulled from the undergarment while said flap is still attached to the undergarment with a force sufficient to cause the flap to detach from the undergarment a tension vector being generated, said tension vector originating at an end portion of said fastener, said tension vector extending toward said main body and crossing said first transverse side at a certain location thereof; r) said flap being characterized in that a geometrical configuration of said first transverse side at said certain location is such as to prevent a shear stress level created by said tension vector on said first transverse side to exceed a threshold at which said first flap begins tearing away from said main body. q q t b

23. A sanitary absorbent article as defined in claim 22, wherein the geometrical configuration of said first transverse side at said certain location is a sector of a circle.

24. A sanitary absorbent article as defined in claim 23, wherein the distance between the first and second transverse sides of said first flap measured at said line of juncture being at least about 62 mm.

A sanitary absorbent article as defined in claim 23, wherein said sector of a 10 circle is concave.

26. A sanitary absorbent article as defined in claim 25, wherein said sanitary absorbent article is a sanitary napkin.

27. A sanitary absorbent article substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples. DATED this 17th day of March 2000 Johnson Johnson Inc Moe* Attorney: PAUL G. HARRISON Fellow Institute of Patent Attorneys of Australia of BALDWIN SHELSTON WATERS