HK1019041A

HK1019041A - Sanitary absorbent article having flaps

Info

Publication number: HK1019041A
Application number: HK99104112.7A
Authority: HK
Inventors: R‧布朗热; H‧布里瑟波伊斯
Original assignee: 庄臣及庄臣有限公司
Priority date: 1997-09-26
Filing date: 1999-09-22
Publication date: 2000-01-21

Description

Sanitary absorbent article with flaps

The present invention relates to sanitary absorbent articles such as feminine sanitary napkins and incontinence pads, and more particularly to sanitary absorbent articles having laterally extending flaps.

Sanitary absorbent articles are generally commercially mass produced articles for absorbing and retaining various human excretions. These articles are not only economical but also disposable and therefore convenient to use. They include sanitary napkins, baby diapers, adult incontinence pads, and the like.

The art relating to sanitary absorbent articles, particularly feminine sanitary napkins, has made many advances over the last 20 years. One such feature is that each longitudinal side of the absorbent article extends laterally with a flap when the absorbent article is in a flattened condition. Such flaps may either be integral extensions of the material comprising the absorbent article or may simply be formed by attaching additional material to the absorbent article.

In using these sanitary napkins, the flaps are folded over the edges of the wearer's panties. Such that they can more securely hold the absorbent article to the undergarment, position the article within the undergarment, provide an increased area for absorption of body exudates, and help prevent soiling of portions of the undergarment by protecting the side edges of the wearer's undergarment. Flap designs have been commercially successful and absorbent articles having flaps of various shapes and configurations are used by consumers.

Common knowledge of designers and consumers requires that the flaps on absorbent articles be as large as possible in their line with the main body of the article in order to provide a relatively large amount of protection against leakage of excreta from the side edges of the article. The flaps are thus generally in the shape of an isosceles (i.e., bilaterally symmetrical) trapezoid, i.e., the flaps have a base connected to the longitudinal side of the main body of the article and a top that extends away (and narrows) away from the longitudinal side to the trapezoid. The dimensions of the wings can vary from article to article. Other shapes in the prior art may be loosely described as rectangular, square, or mushroom-shaped.

Problems with absorbent articles having wings of trapezoidal and other common shapes are: the absorbent article is designed and manufactured in a flat condition and in use, the article should generally adopt a two-dimensional, and often three-dimensional, curved condition in order to properly conform to the body of the wearer. By two-dimensional curvature, it is meant that the article will be curved along one axis of a three-dimensional coordinate system consisting of the longitudinal centerline of the article, the transverse centerline of the article, and a line perpendicular to both. By three-dimensionally curved, it is meant that the article will be curved along one axis of more than one three-dimensional coordinate system (e.g., a system having three orthogonal axes).

Feminine sanitary napkins are an example of such absorbent articles, which are most likely to be curved in use in both the sagittal plane (i.e., the longitudinal axis of the absorbent article) and the frontal or coronal plane (i.e., the transverse axis of the absorbent article) of the wearer's body. However, these flaps are generally designed so that they are folded about a linear fold axis generally disposed along the seam line between the flap and the longitudinal side of the main body of the article. The difficulty caused by such an axis of folding is the bending of the edges of the wearer's undergarment that are folded by the flaps. Also, the edges of the panty are typically provided with an elastic material for securing the panty tightly around the wearer's leg, and as the force is applied by the elastic material, a curved shape may be imparted to the flaps and the central portion of the main body of the article, thereby causing the flaps and central portion to tilt upwardly away from the panty and twist, or a flattened shape may be imparted to the edges of the panty, thereby preventing the edges from being pulled up against the wearer's leg. In both cases the comfort and effectiveness of the article and its flaps are sacrificed. Also, the larger the wings, the more acute this problem is. Thus, while the large flaps alleviate one problem (i.e., side leakage protection), they also cause another problem (i.e., instability and stress).

Until now, large wings have been considered by most people to be more beneficial than the disadvantages they cause and are therefore preferred. This has led to efforts to overcome the difficulties associated therewith. As a result, many different solutions have been attempted in the past to address the instability and stresses present in absorbent articles with a universal flap design. Yet totally satisfactory results have not been obtained heretofore because these absorbent articles have always been of a compressed construction, which are complicated, costly and/or complicated to manufacture. Moreover, they tend to be uncomfortable or at least less comfortable to the wearer.

It would be desirable if an absorbent article having an improved flap structure could prevent, alleviate or reduce the stresses that occur in the above-described conventional flap structures, while also being simple in construction and inexpensive to manufacture.

In view of the above, it is an object of the present invention to provide a sanitary absorbent article having an improved flap structure.

It is another object of the present invention to provide a sanitary absorbent article having a wing structure with relatively large wings which not only reduces stress as compared to prior art designs, but which also allows for relatively simple construction and/or reduced manufacturing costs.

The inventors have found that contrary to conventional wisdom, a flap having a configuration that is substantially inverted from the prior art flaps is really desirable. By reversed is meant herein that the wings should increase in width from their proximal side to their distal side substantially constant (i.e. substantially constant expansion, with an inverted cone). A flap having a generally isosceles trapezoidal shape with the distal side larger than the proximal side, i.e., the base of the trapezoid being distal to the flap, not only does the flap appear relatively large, but it also has reduced stress and increased stability compared to prior art flap designs, surprisingly without adversely affecting side leakage protection.

As embodied and described in detail herein, the present invention provides a sanitary absorbent article comprising:

(A) a body having a first longitudinal side, a second longitudinal side generally opposite the first longitudinal side, two generally opposite lateral sides and a longitudinal centerline; and

(B) a first flap attached to the main body portion, the first flap extending from the first longitudinal side of the main body in a flattened condition of the article and folded over the crotch of a wearer's undergarment, the first flap having:

a distal side;

(ii) a proximal side generally opposite the distal side of the first flap, the proximal side being adjacent the first longitudinal side of the main body;

(iii) a first lateral side;

(iv) a second lateral side generally opposite the first lateral side of the first flap; and

(v) a garment facing surface comprising a fastener for fastening the first flap to the garment;

the first lateral side of the first flap and the second lateral side of the first flap diverge substantially continuously from the proximal side of the first flap up to an imaginary line parallel to the longitudinal centerline of the main body portion near the midpoint of the first flap.

The sanitary absorbent article preferably further comprises:

(C) a second flap attached to the main body, the second flap extending laterally from the second longitudinal side of the main body in a flattened condition of the article and being foldable in the crotch of a wearer's undergarment, the second flap having:

a distal side;

(ii) a proximal side generally opposite the distal side of the second flap, the proximal side being adjacent the second longitudinal side of the main body;

(iii) a first lateral side;

(iv) a second lateral side generally opposite the first lateral side of the second flap; and

(v) a garment facing surface comprising a fastener for fastening the second flap to the garment;

the first lateral side of the second flap and the second lateral side of the second flap diverge substantially continuously from the proximal side of the second flap all the way to an imaginary line parallel to the longitudinal centerline of the main body portion near the midpoint of the second flap.

More advantageously:

(A) the first lateral side of the first flap and the second lateral side of the first flap extend straight from the proximal side of the first flap to the imaginary line thereof; and

(B) the first lateral side of the second flap and the second lateral side of the second flap extend substantially straight from a proximal side of the second flap to the imaginary line thereof.

It is further advantageous that:

(A) the first lateral side of the first flap and the second lateral side of the second flap are substantially continuously expandable from a proximal side of the first flap to a distal side of the first flap; and

(B) the first lateral side of the second flap and the second lateral side of the second flap expand substantially continuously from the second flap to a distal side of the second flap.

It is further advantageous:

(A) the first lateral side of the first wing and the second lateral side of the first wing extend substantially straight from the proximal side of the first wing to the distal side of the first wing; and

(B) the first lateral side of the second wing and the second lateral side of the second wing extend substantially straight from a proximal side of the second wing to a distal side of the second wing.

The body of the article is preferably in the form of an hourglass having rounded ends. If the article is of this shape, the first and second lateral sides are relatively short opposing sides and are generally arcuate. The first and second longitudinal sides are relatively long opposing sides and are generally biconcave curved. It is to be noted, however, that the shape of these sides is not essential to the present invention, the lateral and longitudinal sides may be curved or straight, and the main body is generally hour-glass shaped, having a square, rectangular, parallelogram or any other polygon, or even oval or dumbbell shaped absorbent articles are within the scope of the present invention and are not essential to the present invention. In such a case (i.e. where the body is not rectangular), the longitudinal sides of the layer will be considered to be the opposite sides having a greater length than the other opposite sides of the body. It is not possible to make such a limitation, and any pair of opposing sides can be considered a longitudinal side, i.e. in the limit any portion of two opposing sides can be considered a longitudinal side. In any case, the lateral sides are a pair of opposing sides (i.e., side portions) that are intersected by the longitudinal centerline of the article, which is defined hereinafter.

For most articles, its centerline is an imaginary line extending along the longitudinal axis of the article and dividing the article into identical or slightly identical, but not necessarily mirror-imaged, halves. Similarly, the transverse centerline is an imaginary line perpendicular to the longitudinal centerline and generally disposed along the transverse axis of the article, dividing the article into identical or slightly identical, but not necessarily mirror-imaged halves.

The wings are preferably generally trapezoidal in shape, and more preferably are symmetrical (i.e., bilaterally symmetrical) trapezoidal in shape. In the case of the invention, the wings are of such a shape that: the "top" of the trapezoid is considered the shorter of the two generally parallel sides, while the "bottom" of the trapezoid is the longer of the two generally parallel sides. It should be noted that the meaning of the word "substantially parallel" is to emphasize the sides of many different configurations, including those that are slightly curved or angled and those that are formed by two or more straight edges connected at a relatively large angle.

It should be emphasized that these trapezoidal shapes are not essential to the invention, and wings shaped as various polygons are within the scope of the invention and will produce the same beneficial effect.

The wings of the present invention may be an integral extension of the material (or materials) forming the main body of the article. By way of example, the flaps may be extensions of the cover material and barrier material joined together generally at the periphery of the flaps. These flaps may also be themselves formed as integrally extending flaps of the material forming the main body of the article, which flaps have been reattached to the underside of the main body (i.e., on the side facing the pants); all of these descriptions are as described in co-pending international patent application (PCT/CA97/00990,1997, 12 months filing) having a common assignee. Which is hereby incorporated by reference in its entirety. Alternatively, the flaps may be of another material that is attached to the main body of the article after the main body has been formed, typically by affixing such material to the garment-facing surface of the main body.

In any event, if the article is in a flat configuration (i.e., if the article is laid on a flat surface) the flaps extend laterally outward from the longitudinal sides of the main body of the article (i.e., away from the longitudinal centerline of the article). The flaps are flexible and can be folded along the edges of the crotch of the wearer's undergarment. The distal side of the flap is thus the side of the flap that is generally opposite (generally parallel) to the longitudinal centerline of the main body, and the side of the flap that is furthest from the point of attachment of the flap to the main body, the distal side of the flap forming the base of the trapezoid (if the flap is trapezoidal in shape). It is preferably straight or slightly curved, i.e. substantially straight. It should be noted, however, that the distal side of the flap need not be a single straight line or curve. The distal side may consist of a series or two or more line segments and/or arcs joined together at some relatively large angle (i.e., greater than 120 °).

The side opposite the distal side (and in most cases between the distal side and the longitudinal centerline) is proximal to the flap. If the wings are integrally extended from the material forming the main body of the article, rather than being formed by flaps as described above, the proximal sides of the wings will be joined to the longitudinal sides of the main body. Further, if the wings are additional material added to the main body (secured to the panty-facing surface of the main body after the main body has been formed) or the wings are formed by one of the flaps described above, the proximal side of the wings is the part which is attached to the longitudinal side of the main body. Thus, typically in this state, the proximal end of the flap is not actually a flap edge. If the proximal side cannot be defined in other ways, it should be considered along that folding axis of the undergarment of the wearer of the article. In any case, the apex of the trapezoid forms the proximal side of the flap (when the flap is trapezoidal).

It is noted that wings constructed in accordance with the teachings of the present invention can have a different sized proximal length. Although a preferred proximal length is 6.2cm, wings having a length less than or greater than 6.2cm, such as 3,4,5, 6, 7, 8,9, 10, 11, 12, 13, and 15cm, are also within the scope of the present invention.

The remaining two sides of the trapezoid form a second lateral side and a second lateral side of the flap. They expand substantially continuously from the proximal side of the flap at least as far as a line parallel to the longitudinal centerline in the vicinity of the flap midpoint, which is a point equidistant from a first imaginary line connecting the intersection of the flap first lateral side with the flap distal side and the intersection of the flap second lateral side with the flap distal side and a second imaginary line connecting the intersection of the flap first lateral side with the main body longitudinal side and the intersection of the flap second lateral side with the main body longitudinal side, and which is also equidistant from the flap first lateral side and the flap second lateral side.

It is preferred that the first and second lateral sides expand substantially continuously from the proximal side of the flap at least until along a line measuring the "longitudinal length" of the flap fastener.

More preferably, they expand substantially from the proximal side until the distal side. "substantially continuously distended" in the context of the present invention is to be understood as an indication of the state in which an imaginary line parallel to the longitudinal centerline of the article continuously increases in length from the first lateral side of the flap to the second lateral side of the flap in a direction away from the proximal side to the distal side.

In addition, the generally constant divergence of the lateral sides is preferably generally straight, such that the flaps will flare distally to their proximal sides, thereby providing a steady, continuous decrease in the distance between the lateral sides (as measured along a line parallel to the longitudinal centerline of the article) distally to proximally.

An article comprising a main body and wings will have two opposing major surfaces which can be distinguished depending on where the article is in use. The surface that faces and contacts the body of the wearer when the article is in use is referred to as the body-facing surface. That opposite surface is referred to as the garment-facing surface, which in use is generally facing the wearer's garments (i.e. the external environment if the article is not covered by a garment).

Both the garment-facing surface of the main body and the garment-facing surface of the flaps typically include fasteners for securing the article to the wearer's undergarment. It is advantageous to have the longitudinal length of each fastener located on the garment facing surface of each flap be no less than 85% of the proximal length of the flap in which the fastener is located. In this specification the term "longitudinal length" is to be understood as the maximum length of the fastening member measured along a line parallel to the longitudinal centre line of the article. (for this case, the gap in the case of a continuous fastener is omitted.) the longitudinal length of the fastener may be referred to in everyday colloquial as the fastener width.

It should be noted that it is not necessary for the length of the fastener to exceed the proximal length of each line along the longitudinal centerline of the article, and only the "longitudinal length" (at a maximum) along a single such line will suffice.

It is further advantageous to have the longitudinal length of the fastener be greater than 85% of the proximal side of the flap in which the fastener is located. In this case, the longitudinal length is 85%, 90% and 95% of the proximal side, respectively, which are more preferable values. It is further advantageous to have the fastener have a longitudinal length that is not less than the proximal length of the wings on which the fastener is located. In this case, longitudinal lengths of 100%, 105% and 110% of the proximal side, respectively, are more preferred.

It has been found that if these longitudinal length values are used for the fastener, the stability of the central portion of the article is improved compared to prior art articles. Improved stability means that the article will be less likely to move relative to the body when the article is being used by the wearer, and it is believed that a greater longitudinal length of the fastener contributes to the stability of the central region of the article.

Preferably when the article is in a flat condition:

(a) each lateral side of the first flap makes an angle of less than 90 deg., and preferably not less than about 60 deg., with the first longitudinal side of the main body, an

(b) Each lateral side of the second flap makes an angle of less than 90 deg. with the second longitudinal side of the main body, and preferably does not make an angle of less than about 60 deg..

More preferably, both angles are around 75 °.

It should be noted that the wing lateral sides need not be substantially straight, but may be slightly concavely curved, and if this is the case, the angle formed in the above should be understood as the angle formed between the tangent to the lateral side and the adjacent longitudinal side, the tangent passing through the intersection of that lateral side and the adjacent longitudinal side.

It has been unexpectedly found that large flaps provide many benefits when the flaps are the flaps described above, overcoming certain disadvantages. This reduces stress, the article is reliably positioned in the wearer's undergarment, and there is no significant damage to the side leakage protection. Without wishing to be bound by any particular theory, it is believed that the stresses induced in prior art flaps diminish as the relative distal extent of the flap length along the flap fold axis at the wearer's panty edge decreases. Moreover, the increased width of the flaps in the distal region increases the area of adhesive present and the flaps are shaped so that the total or near total effective amount of adhesive is increased, both of which enable the flaps to be better secured to the panty and also enable the article to be effectively secured to the panty.

Preferably, the fastener of the first flap and the fastener of the second flap each further comprise:

(1) a central region having adhesive strength, and

(2) an end region having a bond strength that is less than the bond strength of the central region.

In this regard, the fixture may be roughly divided into three zones: a first end region adjacent the first lateral side of the flap, a second end region adjacent the second lateral side of the flap, and a central region between the end regions. The term "zone" is herein understood to include discontinuities (i.e. gaps) in the fastener, the gaps having a length less than the longitudinal length of the fastener.

Also in the preferred embodiment, the end regions of each seating member do include a plurality of discontinuities (i.e., gaps) which serve to reduce the strength of the bond between the end region and the central region. Other methods are of course possible. For example, an adhesive having a different physicochemical property (e.g., an adhesive having a different chemical composition) than the central region may be used in the end regions. Talc and the like may be added to the adhesive applied to the end region, and these materials partially adhere to the adhesive, reducing the overall bond strength of the adhesive. Finally, it is also possible to simply apply less adhesive (i.e. reduce the adhesive area) at the end regions.

The most preferred sanitary absorbent articles are feminine sanitary napkins, which are placed in the perineal region of a woman and are used to absorb menses and other discharged fluids.

Other objects and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings.

The following detailed description of preferred embodiments of the invention refers to the accompanying drawings in which:

FIG. 1 is a top plan view of a feminine sanitary napkin according to a preferred embodiment of the present invention;

FIG. 1a is a cross-sectional view of the sanitary napkin taken along line 1a-1a of FIG. 1;

FIG. 1b is an enlarged top plan view of the first flap of the sanitary napkin of FIG. 1 (with the peripheral seal line removed for clarity);

FIG. 2 is a bottom plan view of the sanitary napkin of FIG. 1;

FIG. 2a is a planar enlarged bottom view of the first wing of FIG. 1b (with the peripheral seal line removed for clarity);

FIG. 2b is an enlarged bottom plan view of the first wing of another embodiment of the present invention similar to FIG. 2a (with the peripheral seal lines removed for clarity);

FIG. 3 is an enlarged bottom plan view similar to FIG. 2a of the first wing of the third embodiment of the present invention (with the peripheral seal lines removed for clarity);

FIG. 4 is an enlarged bottom plan view similar to FIG. 2a of the first wing of the fourth embodiment of the present invention (with the peripheral seal lines removed for clarity);

fig. 5 is a bottom plan view of the sanitary napkin of fig. 1 placed on the inside of a typical undergarment.

The drawings are intended to illustrate preferred embodiments of the invention. It is emphasized that the description and drawings are merely used for the purpose of illustration and to facilitate an understanding of the invention, and are not intended to limit the invention.

As shown in FIG. 1, the preferred embodiment of the present invention is a feminine sanitary napkin 20. Referring to fig. 1a, the sanitary napkin is a laminate structure preferably comprising a fluid permeable cover 22, an absorbent system 24 and a fluid impermeable barrier 30.

Covering layer

The cover layer 22 may be a relatively low density, bulky and soft nonwoven web material. The cover layer 22 may be composed of only one type of fiber, such as polyester or polypropylene, or may be composed of bicomponent or conjugate fibers having a low melt component and a high melt component. The fibers may be selected from a variety of natural and synthetic materials such as nylon, polyester, rayon (blends with other fibers), cotton acrylic, and the like, as well as combinations thereof.

The bicomponent fiber may be composed of a polyester core and a polyethylene sheath. Suitable bicomponent materials are fusible nonwoven fibers. Such fusible fibers are described in U.S. patent 4555430 issued to Mays on 26/11/1985. The use of fusible fibres allows the cover layer to be easily secured to the adjacent transmission and/or barrier layers.

Although the individual fibers comprising the cover layer may not be particularly hydrophilic, it is preferred that the cover layer 22 have relatively high wettability properties. The cover layer should contain a large number of relatively large pores. This is because the cover layer 22 is intended to rapidly absorb body fluids and then transport them away from the body or deposit. It is preferred that the fibers comprising the cover layer 22 should not compromise their physical properties after wetting, in other words, they should not gather or lose elasticity when subjected to water and body fluids. The cover layer 22 is believed to allow fluid to pass through it easily. The cover layer 22 also serves to quickly transfer fluid to other layers of the absorbent structure 24. Thus, the cover layer 22 is preferably wettable, hydrophilic and porous. If the cover layer 22 is composed of synthetic hydrophilic fibers, such as polyester or bicomponent fibers, the cover layer 22 may be treated with a surfactant to achieve the desired degree of wettability.

Most preferably, the cover layer 22 is composed of a polymer film having large pores because such a high porosity film can accomplish rapid fluid transport to the inner layers of the system. Porous coextruded films (e.g. RETICULON) such as described in U.S. Pat. No. 4690679^TMTrademark) is effective as a cover layer in the absorbent structure of the present invention.

The cover layer 22 may be embossed onto other portions of the absorbent system 24 to help improve the hydrophilic properties by fusing the cover layer to the next layer.

Absorbent system-transfer layer

A fluid transfer layer 26 forming part of the absorbent system 24 is adjacent to the cover layer 22 on the inside and joined to the cover layer 22. The transfer layer 26 provides a means for receiving fluid from the cover layer 22 and retaining the fluid until the high density absorbent core is received by a suitable absorbent fluid.

The transmission layer 26 is preferably denser than the cover layer 22 and has relatively small pores that are larger than the cover layer 22. This will allow the transfer layer 26 to contain and retain bodily fluids until the bodily fluids exit from the outer layer of the cover layer, thereby preventing rewetting of fluids into the cover layer 22 and its surface, however, the density of the transfer layer 26 should preferably not be so high as to prevent fluid from passing through the layer 26 and into the absorbent core 28.

The transmission layer 26 may be constructed of fibrous materials such as wood pulp, polyester, rayon, flexible foam, the like, or combinations thereof. The transfer layer 26 may also be a thermoplastic fiber in order to secure the transfer layer and maintain its structural integrity. One or both sides of the transfer layer 26 may be treated with a surfactant to increase its wettability, although the transfer layer 26 is generally relatively hydrophilic and does not require treatment, and it is preferred to join both sides of the transfer layer 26 to adjacent layers (i.e., the cover layer 22 and the absorbent core 28).

Absorbent system-absorbent core

The absorbent core 28 is directly adjacent to and joined to the transfer layer 26. The absorbent core 28 is preferably a highly densified layer having small pores, which has a large fluid retention capacity and exceptional fluid retention properties. The absorbent core 28 is preferably composed of compressed moss material, in particular sphagnum moss formed into sheets by air-laying or wet-laying and then calendered to obtain a relatively thin sheet, i.e. from about 0.025cm to 0.25cm thick, and a relatively dense sheet, i.e. from about 0.2 to 1.0g/cm thick³The sheet-like structure of (1). The structure may comprise a layer of Kratt spun paper laminated to one or both surfaces of a layer of moss ground coating. Preferably the fibres are mixed with moss material. Suitable fiber components are natural or synthetic textile fibers such as rayon, polyester, nylon, acrylic, and the like, having a length of from about 0.62 to 3.75cm and a denier of from about 1.0 to 5 denier. The percentage of the fiber component is from about 2 to 20% by weight, preferably from 4 to 8%. The absorbent core 28 may also be comprised of other components such as wood pulp, synthetic wood pulp, thermomechanical pulp, mechanically comminuted pulp, polymers, surfactants, superabsorbent material, and the like.

In another embodiment, the absorbent system 24 includes a single layer of fluff pulp material (omitting the transfer layer). The absorbent core 28 preferably comprises fluff pulp materials and may optionally include other absorbent materials or non-absorbent materials that help stabilize the absorbent structure, such as conjugate fibers, fusible fibers, binders, moss peat moss pellets, superabsorbent materials and the like and mixtures thereof, and may optionally include other absorbent materials or materials that help stabilize the absorbent structure, such as conjugate fibers, fusible fibers, binders, moss peat moss pellets, superabsorbent materials and the like and mixtures thereof.

Barrier layer

Located beneath the absorbent system 24 is a barrier layer 30. The barrier layer 30 is comprised of a fluid impermeable film that serves to prevent fluid that enters the absorbent core from spilling out of the sanitary napkin and soiling the wearer's undergarment. The barrier layer 30 is preferably made of a polymeric film such as polyethylene film, which is both inexpensive and readily available. The polyethylene film may completely block the passage of liquid or gas that may be vented from the absorbent system 24, and in one variation, a breathable film that blocks fluid while allowing gas to pass through may be used.

The cover layer 22 and the barrier layer 30 are joined along their edge portions to form an enclosure that maintains the closed state of the absorbent system 24. Such bonding may be accomplished by adhesives, thermal bonding, ultrasonic welding, radio frequency sealing, mechanical crimping, and the like, as well as combinations thereof. The perimeter seal is shown in figure 1 with reference numeral 92.

Structure of protective wing

Referring to fig. 1 and 1b, the sanitary napkin 20 includes a main body 21 having a first lateral side 36 and an opposite second lateral side 38. Each lateral side 36,38 is curved (curved outwardly so that the lateral sides 36,38 are bilaterally convex). Any particular curvature is not essential to the invention. The sanitary napkin 20 also has a curved first longitudinal side 40 and an opposing second longitudinal side 42, each of which is inwardly curved (i.e., the longitudinal sides 40,42 are concave on both sides), and any particular curvature is not essential to the present invention. The main body 21 of the sanitary napkin 20 is shaped as a slightly hourglass when viewed from above as shown in fig. 1. The contour of the sanitary napkin 20 is symmetrical about an imaginary centerline extending longitudinally below the sanitary napkin 20 and a transverse centerline 47 extending transversely across the sanitary napkin 20.

The first flap 44 extends laterally from a central region of the first longitudinal side 40 of the main body 21. The first flap 44 is generally in the shape of an isosceles (bilaterally symmetrical) trapezoid. Thus, the first flap 44 has a distal end 52 that forms the base of the trapezoid. The distal end 52 is preferably slightly upwardly convex and curved. The sides of the trapezoid are substantially straight and form a first lateral side 48 and a second lateral side 50 of the first flap. The top edge of the trapezoid constitutes the proximal side 59 of the first flap 44. When the first flap 44 is formed by an integral extension of the cover 22 and the barrier layer 30 of the main body 21, the proximal side 59 of the first flap 44 is attached to the first longitudinal side 40 of the main body 21 of the sanitary napkin 20.

The first lateral side 48 of the first flap 44 passes through the distal side 52 of the first flap 44 at a (first) intersection point 54. Likewise, the second lateral side 50 of the first flap 44 passes through the first flap 44 and the distal side 52 at a (second) intersection point 56. A first (imaginary) straight line 58 may be drawn between the two intersection points 54, 56. (the length of this line is shown by reference numeral 58a, which is about 7.0 cm.) the first lateral side 48 of the first flap 44 passes through the first longitudinal side 40 of the main body 21 at the (third) intersection point 61; likewise, the second lateral side 50 of the first flap 44 passes through the first longitudinal side 40 of the main body 21 at the (fourth) intersection point 63. A second (imaginary) straight line 60 (representing the proximal side 59) may be drawn between the intersection points 61,63 (the length of this line is shown with reference numeral 60a and is about 6.2 cm.) the length 58a of the first straight line 58 is greater than the length 60a of the second straight line 60.

The first flap 44 has a midpoint 57 that is equidistant from the first imaginary line 58 and the second imaginary line 60, as well as equidistant from the first lateral side 48 and the second lateral side 50 of the first flap 44. An imaginary line 55 parallel to the longitudinal centerline may be drawn through the midpoint 57.

The angle 62 formed by the intersection of the first lateral side of the first flap 44 with the first longitudinal side 40 of the main body 21 and the angle 64 formed by the intersection of the second lateral side 42 of the second flap 46 with the second longitudinal side 42 of the main body 21 are both about 75.

The second flap 46 extends laterally from a central region of the second longitudinal side 40 of the main body 21. The second flap 46 is generally in the shape of an isosceles (bilaterally symmetrical) trapezoid. Thus, the second flap 46 has a distal end 70 that forms the base of the trapezoid. The distal end 70 is preferably slightly upwardly convex and curved. The sides of the trapezoid are substantially straight and form a first lateral side 66 and a second lateral side 68 of the second flap. The top edge of the trapezoid constitutes the proximal side 77 of the second flap 46. When the second flap 46 is formed by an integral extension of the cover 22 and the barrier layer 30 of the main body 21, the proximal side 77 of the second flap 46 is joined to the second longitudinal side 42 of the main body 21 of the sanitary napkin 20.

The second lateral side 66 of the second flap 46 passes through the distal side 70 of the second flap 46 at a (first) intersection point 72. Likewise, the second lateral side 68 of the second flap 46 passes through the second flap 46 and the distal side 70 at a (second) intersection point 74. A first (imaginary) straight line (not shown) may be drawn between the two intersection points 72, 74. (the length of this line, shown by reference numeral 76a, is about 7.0 cm.) the first lateral side 66 of the second flap 46 passes through the second longitudinal side 42 of the main body 21 at the (third) intersection point 79; likewise, the second lateral side 68 of the second flap 46 passes through the second longitudinal side 42 of the main body 21 at the (fourth) intersection point 81. A second (imaginary) straight line (not shown) may be drawn between the intersection points 79,81 (the length of this line is shown with reference numeral 78a and is about 6.2 cm.) the length 76a of the first line is greater than the length 78a of the second line.

The second flap 46 has a midpoint (not shown) that is equidistant from the first and second imaginary lines and is also equidistant from the first and second lateral sides 66, 68 of the second flap 46.

The angle 80 formed by the intersection of the first lateral side 66 of the second flap 46 with the second longitudinal side 42 of the main body 21 and the angle 82 formed by the intersection of the second lateral side 50 of the first flap 44 with the first longitudinal side 40 of the main body 21 are both about 75.

Adhesive fastener

Referring to fig. 2, to enhance the stability of the sanitary napkin 20 on the panty-facing side 85 of the barrier layer 30 of the main body 21, five fasteners 83,86,88,94,98 are provided for securing the sanitary napkin 20 to the wearer's undergarment during use of the sanitary napkin. These fasteners 83,86,88,94,98 are of a conventional design, such as an adhesive material, e.g., hot melt adhesive, that creates a temporary bond with the panty material. One of the fasteners 88 is located in the central region of the main body 21 of the sanitary napkin 20, the second fastener 94 and the third fastener are located in the region of the lateral sides 38, respectively, of the main body 21 of the sanitary napkin 20, and the fourth fastener 83 and the fifth fastener 86 are located in the region of the distal edges 52,70, respectively, of the first flap 44 and the second flap 46. Separate release papers 96,99 overlie the second and third fastening members 94,98, and a single release paper 84 overlies the first, fourth and fifth fastening members 88, 83, 86.

Referring to FIG. 2a, there is shown the garment-facing surface 85 of the first flap 44 shown in FIG. 4, which includes the fourth adhesive 83 described above. (the release paper 84 has been torn off.) the adhesive has been applied in a generally rectangular shape with the long side 83a parallel to the longitudinal centerline of the article 20. The fourth adhesive 83 has a width 83w (measured parallel to the transverse centerline of the article) of 1.5cm and a length 831 (measured parallel to the longitudinal centerline of the article) of 4.8 cm. Although not illustrated, the fifth adhesive 86 has the same structure.

Alternative embodiments

Referring to FIG. 2b, there is shown an alternative embodiment of the present invention wherein the panty-facing side surface 285 of the wings 244 (similar to that shown in FIG. 2 a). Specifically, that "fourth" adhesive 283 has been applied in a discontinuous manner, i.e., with gaps 201a,201b,201c and 201d in the continuous adhesive 283. Thus, the adhesive 283 exhibits some rectangles 203a,203b,203c,203d and 203 e. The width 203w of the central rectangle 203c is 1.5cm and the length 203c1 is 1.6 cm. The other rectangles 203a,203b,203d and 203e (two on either side of the central rectangle) each have a width 203w of 1.5cm and lengths 203al,203bl,203dl and 203e1 of 0.5 cm. Rectangles 203a,203b,203c,203d and 203e are spaced from each other by a distance of 0.3 cm. These gaps 201a,201b,201c and 201d are intended to reduce the bond strength of the adhesive 283 on those regions adjacent the lateral sides 248,250 of the flaps 244. The adhesive 283 itself is the same as described with reference to fig. 2 a. Also, although not shown, the "fifth" adhesive has the same structure.

Referring to fig. 3, another embodiment of the present invention is shown. In this embodiment, the longitudinal length 390a of the "fourth" fastener 383 (i.e., on the first wing 344) exceeds the length 360a of the second line (representing the proximal side) on the first wing 344. Moreover, the lateral sides 348 and 350 are substantially straight only between their respective intersection point 361,363 with the proximal side 359 and their respective intersection points 391a,391b with a line along which the longitudinal length of the adhesive 383 is measured. Also, although not shown, the "fifth" adhesive has the same structure.

Figure 4 shows another alternative embodiment of the present invention wherein the first lateral side 448 of flap 444 and the second lateral side 450 of the first flap 444 are curved (when opposed to being substantially straight). These lateral sides 448,450 are generally continuously flared in accordance with the teachings of the present invention. (i.e., between their respective points of intersection 461,463 with the proximal side 459 and their respective points of intersection 491a,419b with a line 491 along which the longitudinal length of the adhesive 483 is measured.) additionally, the maximum longitudinal length 490a of the fastening device 483 exceeds the length 460a of a line 460 joining the points of intersection 461,463 of the first and second lateral sides 448, respectively, with the first longitudinal side 440 of the main body of the article (i.e., the proximal side of the flap 444). Also, although not shown, the "fifth" adhesive has the same structure.

To use the sanitary napkin 20, the release paper 84,96,99 is torn away to expose the fasteners 83,86,88,94 and 98. The sanitary napkin 20 is then secured in the perineal region of the panty 18 as shown in figure 6, and the first flap 44 and the second flap 46 are then folded along each side of the crotch region of the panty. Fasteners 83,86,88,94 and 98 are adhered to the undergarment 18 to hold the sanitary napkin 20 in place.

The above description of preferred embodiments should not be construed in a limiting sense as other variations, changes and modifications are possible within the spirit and scope of the present invention. The scope of the invention is defined by the claims and their equivalents.

Claims

1. A sanitary absorbent article comprising:

(B) a first flap attached to the main body portion, the first flap extending laterally from the first longitudinal side of the main body in a flattened condition of the article and folded over the crotch of a wearer's undergarment, the first flap having:

a distal side;

(ii) a proximal side generally opposite the distal side of the second flap, the proximal side being adjacent to the first longitudinal side of the main body;

(iii) a first lateral side;

2. A sanitary absorbent article according to claim 1, further comprising:

(C) a second flap attached to the main body, the second flap extending from the second longitudinal side of the main body in a flattened condition of the article and being foldable in the crotch of a wearer's undergarment, the second flap having:

a distal side;

(iii) a first lateral side;

the first lateral side of the second flap and the second lateral side of the second flap diverge substantially continuously from the proximal side of the second flap up to an imaginary line parallel to the longitudinal centerline of the main body portion near the midpoint of the second flap.

3. A sanitary absorbent article according to claim 2 wherein:

(B) the first lateral side of the second flap and the second lateral side of the second flap extend substantially straight from a proximal side of the second flap to an imaginary line thereof.

4. A sanitary absorbent article according to claim 2 wherein:

5. A sanitary absorbent article according to claim 4 wherein:

(A) the first lateral side of the first wing and the second lateral side of the first wing extend substantially straight from the proximal side of the first wing to the distal side of the first wing;

6. A sanitary absorbent article according to claim 5 wherein the distal side of each flap is substantially straight.

7. A sanitary absorbent article as claimed in claim 2,3,4,5 or 6, wherein when the article is in a flattened condition:

each lateral side of the first flap intersects the first longitudinal side of the main body at an angle of no less than about 60 °; and

each lateral side of the second flap makes an angle of not less than about 60 with the second longitudinal side of the main body.

8. A sanitary absorbent article according to claim 7 wherein when the article is in a flattened condition:

(a) each lateral side of the first flap intersects the first longitudinal side of the main body at an angle of no less than about 75 °; and

(b) each lateral side of the second flap makes an angle of not less than about 75 with the second longitudinal side of the main body.

9. A sanitary absorbent article according to claim 2,3,4,5 or 6 wherein

The fastener of the first flap has a longitudinal length that is no less than 85% of the proximal length of the first flap; and

the fastener of the second flap has a longitudinal length that is no less than 85% of the proximal length of the second flap.

10. A sanitary absorbent article according to claim 9 wherein:

the fastener of the first wing has a longitudinal length no less than a length proximal to the first wing; and

the fastener of the second flap has a longitudinal length that is no less than the length proximal to the second flap.

11. A sanitary absorbent article according to claim 9 wherein:

the fastener of the first wing further comprises:

a central region having a bond strength; and

an end region having a bonding strength, the end region and the bonding strength being less than the bonding strength of the central region;

the fastener of the second flap further comprises:

a central region having a bond strength, and

an end region having an adhesive strength, the adhesive strength of the end region being less than the adhesive strength of the central region.

12. The sanitary absorbent article of claim 11 wherein the end regions of each securing member include discontinuities for making the end region bond strength less than the central region bond strength.

13. A sanitary absorbent article comprising:

a body having a first longitudinal side, a second longitudinal side generally opposite the first longitudinal side, two generally opposite lateral sides; and

(B) a first flap attached to the main body portion, the first flap extending laterally from the first longitudinal side of the main body in a flattened condition of the article and being folded over the crotch of a wearer's undergarment, the first flap having:

a distal side;

(ii) a proximal side generally opposite the distal side of the first flap, the proximal side being adjacent the first longitudinal side of the main body; and

(iii) a garment-facing surface comprising a fastener for fastening said second flap to the garment, said fastener having a longitudinal extent of not less than 85% of the proximal extent.

14. A sanitary absorbent article according to claim 13, further comprising:

a distal side;

(ii) a proximal side generally opposite the distal side of the second flap, the proximal side being adjacent the second longitudinal side of the main body; and

(iii) a garment facing surface comprising a fastener for fastening the second flap to the garment, the fastener having a longitudinal length which is not less than 85% of the proximal length of said second flap.

15. A sanitary absorbent article according to claim 14 wherein:

the fastener of the first wing has a longitudinal length no less than the proximal length of the first wing, an

The fastener of the second wing has a longitudinal length that is not less than the proximal length of the second wing.

16. A sanitary absorbent article comprising:

(A) a body having a first longitudinal side, a second longitudinal side generally opposite the first longitudinal side, two generally opposite lateral sides; and

a first flap joined to the main body portion, the first flap extending laterally from the first longitudinal side of the main body in a flattened condition of the article and folded over the crotch of a wearer's undergarment, the first flap having a garment facing surface including a fastener for securing the first flap to the undergarment, the fastener comprising:

(1) a central region having a bond strength, and

(2) an end region having an adhesive strength, the adhesive strength of the end region being less than the adhesive strength of the central region.

17. The absorbent hygiene article of claim 16, further comprising:

a second flap attached to the main body, the second flap extending laterally from the second longitudinal side of the main body in a flattened condition of the article and being foldable over the crotch of a wearer's undergarment, the second flap having a garment-facing surface including a fastener for securing the second flap to the undergarment, the fastener having:

a central region having a bond strength; and

an end region having a bond strength that is less than the bond strength of the central region.

18. A sanitary absorbent article according to claim 17, wherein the end regions of each securing member comprise discontinuities which provide the end regions with a lower bond strength than the central region.