HK1201435B - Body conforming disposable absorbent article having leg wraps and internal topsheet and method of making same - Google Patents

Description

Unitary disposable absorbent article with leg wraps and internal topsheet and method of making same

Cross Reference to Related Applications

This application claims priority from united states provisional patent application No. 60/916,779 filed on 8/5/2007 in 35u.s.c.119(e), the contents of which are incorporated herein by reference.

Technical Field

The present invention relates to absorbent articles such as disposable diapers, and more particularly to absorbent articles having a unique secondary topsheet and elastic leg wraps capable of forming a reservoir for containing liquid and a plurality of fluid barriers capable of retaining liquid to improve the overall containment characteristics of the absorbent article, particularly containing loose fecal material.

Background

Disposable absorbent articles are worn to contain and absorb urine and fecal exudates. To this end, absorbent articles are provided with improved features or structures that provide a close, comfortable fit around the legs and waist of the user. This close fit enhances the containment capability and leakage prevention capability of the absorbent article.

Typical components in disposable absorbent articles include a liquid permeable inner layer or topsheet, a liquid impermeable outer layer or backsheet, and an absorbent core sandwiched between the inner and outer layers. Elastic barrier leg cuffs, gather components, and waistbands are commonly used to prevent leakage by enhancing the fit of the absorbent article about the thighs and waist of the user. For example, elastic members may be provided longitudinally along the article, generally outboard of the absorbent core, to effect a seal around the legs of the user. In addition, several elastic members (e.g., in the form of elongated elastic strands or threads) may be disposed laterally throughout the waist region, including the side waist regions of the disposable absorbent article, to allow the article to extend in use. In this way, the article can be extended to accommodate variations in waist size and leg size of a user, while maintaining a proper fit and leg seal during use.

One function of absorbent articles, such as disposable diapers and adult incontinent briefs, is to absorb and contain body exudates. Such articles can prevent body exudates from soiling, wetting, or otherwise soiling clothing or other articles (e.g., bedding) that come in contact with the wearer. The disadvantages of such articles are: the leg seals between the absorbent article and the wearer's legs or waist can leak and onto nearby clothing. It is most noticeable with loose fecal material that is not easily absorbed by the absorbent article and it tends to flow unconstrained onto the top surface of the absorbent article.

Current disposable diapers have elasticized leg cuffs to improve wearer comfort and the ability to contain body exudates. These elasticized leg cuffs prove to be effective in preventing leakage from fluid-filled absorbent articles and over garments contacting the edges of the article, because the elasticized leg wraps provide a fluid impermeable barrier between the absorbent core and the contacting garment, and in addition, ensure that a sealing action is provided around the wearer's legs. While these structures are effective, body exudates, especially loose fecal material, can still leak through the elasticized leg cuffs and soil the wearer's clothing because the diaper does not prevent the free flow of such materials, but also does not provide a structure within the diaper that retains such materials, such that the materials flow along the top surface of the topsheet, and tend to route themselves through the elasticized leg cuffs.

Accordingly, it is desirable to provide an absorbent article designed to maintain the proper fit of the absorbent article about the legs of the wearer. Also, it would be desirable to provide an absorbent article that reduces the likelihood of leakage in the legs. It is also desirable to provide a reservoir that can restrict the flow of fecal material within an absorbent article to reduce the likelihood of leakage thereof. In addition, it is desirable to provide an absorbent article that is easy to use and/or remove and has improved wearer comfort.

Disclosure of Invention

The present invention relates to a disposable absorbent article, such as a baby diaper or a disposable elasticated garment (pull-elasticated) comprising a pair of elasticized leg wraps and an inner secondary topsheet for effectively forming a reservoir in the absorbent article for preventing leakage of liquid and/or solid exudates and for providing better fit and appearance. Embodiments of the present invention provide an absorbent article having improved liquid and exudate containment characteristics.

Embodiments of the present invention include a novel secondary topsheet incorporated into a disposable absorbent article characterized by a narrowing of the distance between the pair of elasticized leg wraps as compared to the backsheet distance between the pair of elasticized leg wraps. Narrowing the distance between the pair of elastic leg wraps adjacent the secondary topsheet improves the fit of the disposable absorbent article in the crotch region of the user. In particular, the difference between the topsheet and backsheet spacing allows for the creation of a storage bucket/reservoir effect. Different embodiments of this aspect of the invention are contemplated wherein the cover sheet or topsheet may be a primary or secondary topsheet (i.e., additional topsheet), with or without apertures or slits, have a full or partial length, have a width less than, equal to, or greater than the width of the backsheet, and be partially or fully affixed down on itself, forming a topsheet gap, thereby allowing the effect of forming a storage bucket/reservoir. The details of these and other embodiments are set forth in the detailed description below.

In one aspect of the invention, a disposable absorbent article has a central body and a pair of elasticized leg wraps. The central body comprises an absorbent core and may therefore be referred to herein as a central absorbent assembly. When disposed in a generally flat, open condition, such as prior to being worn by a user or at a later stage in the manufacturing process, the central body is further characterized by: having a front longitudinal edge, a back longitudinal edge opposite the front longitudinal edge, and a longitudinal centerline extending through the front and back edges. These front and back edges at least partially define front and back waist portions, respectively, of the disposable absorbent article. The pair of elastic leg wraps extend longitudinally adjacent opposite sides of the central body. Each leg wrap is spaced outwardly from the side edges of the absorbent core.

In another aspect of the invention, leg wraps incorporated into or with the disposable absorbent article of the present invention are characterized by: having elastic extension properties or elasticity in the longitudinal direction. The leg wraps are elasticized by providing elastic members extending in a longitudinal direction along the disposable absorbent article. The elasticity of the leg wraps improves the fit of the disposable absorbent article around the thighs of the user. In a particular embodiment, the resilient members are parallel to and spaced apart from each other, for example by at least a few millimeters. In a preferred embodiment of the invention, the leg wraps provide the disposable absorbent article with an effective sealing function, such as barrier leg cuffs and leg gathers, and a fit function.

In another embodiment of the present invention, a method of manufacturing a disposable absorbent article is provided. The method comprises the following steps: a central body assembly is provided that includes an absorbent core and a topsheet spanning a topsheet gap, and a pair of elasticized leg wraps defined, for example, by a top layer, a bottom layer, and a plurality of elastic members positioned between the top layer and the bottom layer.

It is another object of the present invention to provide an absorbent article having an inner secondary topsheet and improved elasticized leg wraps defining a plurality of fluid barriers for providing dual containment of the lateral flow of body exudates, thereby improving the containment characteristics of the absorbent article, particularly with respect to loose fecal material.

The absorbent article and method of making the same of the present invention will be readily understood by those skilled in the relevant art from the following detailed description of the drawings, wherein various embodiments of the invention are described by way of illustration of the best mode contemplated for carrying out the invention. The invention is capable of other and different embodiments, and its several details are capable of modifications and its several structural and processing details are capable of modifications in various and obvious respects. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.

Drawings

Figure 1 is a plan view of the inside face of a disposable absorbent article according to the present invention.

FIG. 2 is a plan view of a portion of the interior side of the disposable absorbent article of FIG. 1 in a generally flat, open position.

Fig. 3 is a plan view of the outer side of the disposable absorbent article of fig. 2.

Fig. 4 is a cross-sectional view of the article of fig. 2 and 3, as shown along axis 3-3.

Fig. 5 and 6 are alternative embodiments of the absorbent article of the present invention.

Fig. 7 is a cross-sectional view of an absorbent article of the present invention.

Fig. 8 is a plan view of an absorbent article of an embodiment of the present invention.

Figures 9 to 24 show cross-sectional views of different embodiments of absorbent articles similar to figures 2 and 3.

Figure 25 shows the application of the absorbent article of the present invention to a wearer.

Figures 26 and 27 show cross-sections through the absorbent article and the wearer.

Figure 28 shows an absorbent article on a wearer.

Fig. 29 is a cross-sectional view illustrating the principle of folding side panels according to the present invention.

Figures 30-31 show different embodiments of securing the folded side panels according to the invention.

Fig. 32-36 are cross-sectional views illustrating the formation of a narrower topsheet spacing relative to the backsheet spacing in accordance with the present invention.

Figure 37 shows a different embodiment of placing and attaching a topsheet according to the invention.

Detailed Description

As used herein, the term "disposable absorbent article" refers to articles which are capable of absorbing and containing bodily exudates, and more particularly, relates to articles which are placed against or in proximity to the body of the wearer to absorb and contain the various exudates discharged from the body, as well as to articles which are intended to be discarded after a single use (i.e., they are not intended to be laundered or otherwise restored or reused). A preferred embodiment of the disposable absorbent article of the present invention is shown in figure 1 and designated by the numeral 8. The term "disposable absorbent article" as used herein refers to garments, typically worn by infants and incontinent persons, which are worn about the lower torso of the wearer. However, it should be understood that: the invention is also applicable to other disposable absorbent articles such as incontinence briefs and the like.

Fig. 1 is a plan view of an absorbent article 8. The absorbent article 8 includes: a liquid permeable topsheet or cover 10; a liquid impermeable backsheet 12; an absorbent core assembly 14, for example, disposed between the coverstock 10 and the backsheet 12; a pair of fasteners 16; a flexible elastic leg wrap 18; an inner topsheet 19; and elastic members 20 secured within the leg wraps 18 and capable of defining a plurality of fluid barriers 90 when worn (as shown in figure 28). The liquid permeable coverstock 10, absorbent core 14, topsheet 19 and liquid impermeable backsheet 12 may be assembled together in a variety of well known configurations as will occur to those of skill in the art.

Figures 2 and 3 are plan views of an absorbent article 8 according to the invention in a flat, uncontracted state (i.e., with all elastic induced contraction removed and before any folding operations are performed on the article or a secondary topsheet 19 is added). The new secondary topsheet 19 is not shown in figures 2-24. Fig. 3 is a plan view of the other side (outer side) of the absorbent article 8 of fig. 2.

Referring to fig. 2 and 3, the absorbent article 8 comprises: a liquid permeable topsheet or cover 10; a liquid impermeable backsheet 12; an absorbent core assembly 14, for example, disposed between the coverstock 10 and the backsheet 12; a pair of fasteners 16; a flexible elastic leg wrap 18; and elastic members 20 secured within the leg wraps 18 and capable of defining a plurality of fluid barriers 90 when worn (as shown in figure 28). The liquid permeable coverstock 10, absorbent core 14 and liquid impermeable backsheet 12 may be assembled together in a variety of well known configurations as will occur to those of skill in the art.

Fig. 2 and 3 show an embodiment of an absorbent article 8. Wherein the liquid cover 10 and the backsheet 12 are coextensive and have length and width dimensions generally greater than the length and width dimensions of the absorbent core assembly 14. The coverstock 10 is superposed on the backsheet 12 to form a periphery of the absorbent article 8 including the end edges 28, 30 and the longitudinal edges 32, 34.

The absorbent article 8 has waist regions 36 and 38 which extend from the peripheral end edges 28 and 30 of the absorbent article, respectively, toward the transverse centerline 40 of the absorbent article 8 a distance of from about 1/4 to about 1/3 of the length of the absorbent article 8. The waist regions 36 and 38 comprise the portions of the absorbent article 8 which, when worn, are positioned between the legs of the wearer and cover the lower torso of the wearer.

Referring to fig. 4, the absorbent core assembly 14 includes an absorbent core 42, a liquid permeable nonwoven coverstock 10 and a liquid impermeable backsheet 12. Additional layers of material, such as additional absorbents, cellulosic materials, or nonwovens 44, that can provide additional functions, such as urine storage, rapid urine absorption, and/or urine distribution, can also be provided within the core assembly. The absorbent core 42 may be composed of a combination of cellulose-based absorbent materials, superabsorbent polymers, synthetic nonwovens, or other absorbent materials. The disposable absorbent article 8 is joined together in such a way that the coverstock 10 and the backsheet material 12 completely enclose the absorbent core 42. The coverstock 10 and backsheet 12 may be directly joined together or may be indirectly joined together through an intermediate portion. Materials suitable for each of the core 42, the coverstock 10 and the back sheet 12 are generally known in the art.

The nonwoven coverstock 10 provides a fluid permeable upper layer of the absorbent core assembly which serves to contain the absorbent core components and allows bodily exudates to pass into the absorbent core 42 during use. The length and width dimensions of the cover 10 are preferably greater than the length and width dimensions of the absorbent core assembly 42. These extended side edges of the nonwoven coverstock 10 may extend to the side edges 32, 34 of the absorbent article and serve to provide an upper layer of the composite containing the elastic members 20. The sides of the nonwoven coverstock 10 that extend beyond the elastic leg wraps 18 may or may not be permeable to aqueous fluids.

The cover 10 is preferably comfortable, soft feeling, and non-irritating to the wearer's skin. Suitable coverings may be made from a variety of materials such as porous foams, reticulated foams, apertured plastic films, natural fibers (e.g., wood or cotton fibers), synthetic fibers (e.g., polyester or polypropylene fibers), or a combination of natural and synthetic fibers. Preferably, it is made of a hydrophobic material to isolate the wearer's skin from fluids in the absorbent core 42.

Another embodiment of the absorbent article includes the use of a cover having a plurality of regions of different hydrophilic character achieved by selective treatment of the material with an additive (e.g., a surfactant) that imparts hydrophilic character to the nonwoven. In this embodiment, the cover has a hydrophilic region in the center of the sheet, which is adjusted to correspond to the region of the article in which the absorbent core is disposed. The side regions laterally adjacent the central region may be less hydrophilic or more hydrophilic than the central region, the article formed thereby having a hydrophilic water permeable cover over the absorbent core to allow urine to enter the core, and a hydrophobic water impermeable zone of the cover over the leg wraps to provide a dry feel around the legs and to resist fluid leakage through the leg wraps 18.

The leg wraps 18 may include a plurality of elastic strands 20 associated with each side leg panel 18. In one embodiment, the elastic strands 20 are sandwiched between the nonwoven coverstock 10 and the backsheet laminate 12. The composite of elastic strands 20, nonwoven coverstock 10 and backsheet laminate 12 is secured by using suitable means known to those skilled in the art, such as adhesive bonding using slot coating or spraying of hot melt adhesive, spiral or vortex application, or ultrasonic bonding. In one embodiment, as shown, each side leg panel 18 has 6 elastic strands 20. The elastic cord 20 may be a yarn made of natural or synthetic rubber latex or synthetic elastic material such as highly elastic synthetic fibers. The choice of elastic material should not be limited to elastic strands but may also include bands of elastic material, elastic films, elastic scrims, elastic nonwoven composites, and the like.

Fig. 4 is a cross-sectional view of the embodiment of fig. 2 and 3. Wherein the backsheet material 12 is a laminate of a fluid impermeable polyethylene or polypropylene film 52 having air voids or no air voids and a fluid impermeable polypropylene nonwoven 54. These materials are known to those skilled in the art as cloth-like or fabric backsheets. It is also proposed that: the backsheet material 12 may be a single layer polypropylene film or other suitable composite material.

The fastener 16 may comprise a pressure sensitive adhesive fastening tape, a hook and loop tape, or any other suitable fastening medium secured to the front of the silicone "release" coated polyolefin film. The absorbent article may also have an elastic waistband that utilizes an elastic foam, elastic film, elastic band or other suitable elastic, elastic laminate, stretchable material secured to or between the coverstock and backsheet portions.

One example of a disposable absorbent article according to the present invention provides a tight fitting seal around the thighs of the user, thereby significantly improving its leakage prevention capability. The tight-fitting seal of the garment of the present invention can be further enhanced by the addition of fasteners 16. The fastener 16 may be provided by known adhesive or hook fastening means. The hook fastening means may be selected so that it can engage with loops formed on the surface of the nonwoven fabric. Thus, the nonwoven material of the stretch panel provides the loop component of a hook and loop fastening system similar to those generally known in the art.

In other embodiments, a loop tape (an) may be disposed adjacent the front waist region of the outside surface of the article of the present invention, and a pair of hook fasteners may be disposed in the back inelastic region of each stretch panel. The fastening portion is thus secured directly to the central body rather than to the leading edge of the stretch panel as is generally known in the art, the loop strap may be made of a woven, extruded or non-woven material.

Figures 5 and 6 show various other embodiments of the absorbent article 8. Fig. 5 shows an alternative embodiment in which the side edges 32, 34 of the absorbent article 8 are bent inwardly to define cut-out regions 56. Such a shaped article facilitates a better fit of the article about the waist of the wearer and does not increase the amount of material in the side panel that is creased around the user's legs when worn.

Figure 5 discloses elastic elements 20 which are parallel to at least a part of the side edges 32, 34 of the absorbent article 8. In contrast, figure 6 shows the elastic elements 20 following the inwardly curved side portions of the absorbent article. Some additional structures suitable for use in the present invention are described in U.S. application No.11/295,781 entitled "dispersible Absorbent Article Having Leg Wraps and Method of Making Same," which is hereby incorporated by reference herein and made a part of the present specification.

In figure 6, a further aspect of the invention is shown wherein the absorbent article 8 is defined by a central absorbent core assembly 14 and a pair of leg wraps 18 separated from the absorbent core assembly 14 by a substantially reduced elasticity inelastic region or zone 58. Each inelastic zone 58 is defined between the absorbent core assembly 14 and the nearest elastic strand element 20 of the leg wrap 18.

Referring to fig. 7, a distance h is defined between the side edges of the absorbent core assembly 14 and the elastic strands 20 closest to the core assembly 14 (or in other words, the elastic strands 20 furthest from the side edges 32, 34 of the absorbent article 8). The distance between the strands 20 of elastic material is denoted as distance e.

FIG. 8 also shows another embodiment of a fastener 16 that can be used to practice the present invention. The fastener 16 may be disposed on the exterior of a side panel 35 having one or more elasticized regions 37 and one or more non-elasticized regions 39. Other fastener and Side panel configurations are disclosed in U.S. application No.11/113,114 entitled "Extensible Side Panels For Use With retractable Absorbent Articles," which is hereby incorporated by reference herein and made a part of the present specification.

In the preferred embodiment of the present invention, the number of strands 20 per elastic leg wrap 18 is 4 to 10, preferably 4 to 6. The distance h (width of the inelastic zone 58) is preferably 19mm to 64mm, more preferably 25mm to 40 mm. The distance e between the cords 20 is preferably 4mm to 40mm, more preferably greater than 6mm, and most preferably about 8 mm.

A leg cuff member 64 may be provided on the top surface of the cover 10 of the absorbent article 8. Leg cuff elements 64 may be defined by the material of the cover layer 10 or may be constructed of a different material that is secured to the top surface in a known manner. Those skilled in the art will appreciate the construction of the leg cuff members 64 in the absorbent article 8. As shown in figures 9-13, the leg cuff members 64 may be disposed at different distances from the absorbent core 14.

Fig. 9-24 show cross-sectional views of alternative embodiments of topsheets, backsheets and absorbent articles suitable for use with an internal topsheet 19 (not shown). in some embodiments, a three-piece construction may be used in place of the continuous full width nonwoven coverstock 10. In the central region 10 of the absorbent article, an aqueous fluid permeable material 66 (e.g., a hydrophilically treated polypropylene nonwoven) is disposed over the absorbent core to contain the absorbent material and allow urine to enter the absorbent core 14. Another piece of material 68 forms the top layer of the elastic side panel 18 along each side edge of the article. Such materials may be selected from suitable materials such as water-permeable polypropylene nonwovens, water-impermeable polypropylene nonwovens, polypropylene films and the like. Figure 9 shows an absorbent core cover material 66 overlapping an outer elastic composite cover material 68. Figure 10 shows the absorbent core cover material 66 superposed under the elastic composite covering material 68.

In the embodiment shown in figure 11, the absorbent core assembly 42 is enclosed by a nonwoven fluid permeable coverstock 70 and a fluid impermeable backsheet 72. In this embodiment, the cover 70 and backsheet 72 do not extend to the outer edges of the absorbent article. The single layer of nonwoven fabric 74 is folded around the elastic strands 20 and encloses the elastic strands 20. The elastic composite is then attached to the sides of the absorbent core 14 by any suitable means, such as by hot melt adhesive or ultrasonic bonding.

In the example shown in fig. 12, the cover material 10 extends continuously over the entire width of the absorbent article 8, as in the first embodiment of the invention. In this embodiment, the underside of the elastic composite on each leg wrap 18 is enclosed by a separate piece of conformable material 78.

Fig. 13 shows an alternative embodiment to the embodiment shown in fig. 11. The embodiment differs in that: the elastic strands 20 within the elastic composite secured between the coverstock and backsheet portions of the core assembly 14 are enclosed by two separate layers of suitable material.

Figures 14-24 show other embodiments in which the underside of the elastic composite side panel is formed from a material such as a fluid impermeable polypropylene nonwoven that extends continuously across the entire width of the absorbent article.

FIGS. 25-28 show a disposable absorbent article adapted for use by a wearer. In these figures a new internal topsheet 19 is shown. The absorbent article 8 is folded inwardly at point 80 and outwardly at point 82. The absorbent article 8 may naturally conform to the shape shown in figures 25-28. It may be necessary or useful to pre-secure the article in this configuration by using multiple adhesives or by using any other suitable means for ensuring that the article properly fits the wearer.

The effect of this folding pattern of the article is twofold. First, the elastic leg wraps 18 desirably lie against the body of the wearer and fit securely around the thighs and buttocks of the user. This enables a substantially fluid impermeable seal to be formed around the legs, crotch and thighs of the user, thereby enabling reduced leakage to occur. Second, the absorbent core assembly 14 is held away from the wearer's body, particularly in the crotch region of the article. This serves to create a void space 84 between the user's body and the absorbent core assembly 14.

As shown in figure 26, the void space 84 may have a generally trapezoidal appearance with the bottom having a length generally equal to the width of the absorbent core 42, the sides having a length generally equal to dimension X, and the top having a length dependent upon the angle formed between the bottom and sides. The portions of the article 8 may pivot or rotate relative to each other so that the absorbent core 42 and leg wraps 18 are free to move on the wearer. This pivoting effect enables the leg wraps 18 to move during use while maintaining an effective leg seal.

The void spaces 84 formed by the structure of the absorbent article 8 are capable of holding the absorbent core 42 away from direct contact with the wearer's skin or body. For example, rewet or wetting of the user's skin by bodily waste fluids not fully received by the superabsorbent material within the absorbent core 42 can be reduced, thereby enhancing the comfort of the wearer.

Referring particularly to fig. 25 and 28, reservoir 26 is a structure capable of collecting, containing and retaining bodily exudates. Exudates floating or flowing along the top surface flow into the side walls of the reservoir 26 and down the side walls to be collected at the bottom of the reservoir 26 until the absorbent article 8 is removed. The reservoir 26 is thus particularly effective for exudates, particularly loose fecal material that is not readily absorbed by the absorbent core 14 and tends to "float" on the coverstock 10.

For example, the reservoir 26 may be disposed at least partially between the elastic member 20 and the longitudinal centerline of the absorbent article 8 with material in the region of reduced elasticity 58. The reservoir 26 may be made of a material known in the art that is sufficiently compliant and comfortable to assume a bag or pocket-like shape. The material may be absorbent, wicking, or impermeable to the exudates. For example, the reservoir 26 may include one component (i.e., the coverstock 10, backsheet 12 or leg wrap 18) or any combination of these components or other components of the absorbent article 8 configured or folded to form a reservoir. Additionally, the reservoir 26 may have different shapes and cross-sections so long as a bag or well-like shape is formed to contain the discharge. Preferably, the reservoir 26 is formed by folding the material in the region of reduced elasticity 58 and securing the folded portion to the portion of the coverstock 10 adjacent the absorbent core 14.

Fig. 28 shows temporary reservoir 26 and void 84, wherein reservoir 26 contains fluid prior to absorption by core 14. Fluid is prevented from passing through the side leg panels 18 by a series of elastic gathers defining a plurality of fluid barriers indicated by the numeral 90. Fluid passing through one fluid barrier 90 will encounter the more outboard fluid barrier 90. As a result, multiple sealing structures can be provided by the leg wraps 18.

It has been found that: the desired trapezoidal shape of the void 84 and/or reservoir 26 is difficult to form and maintain in each application, since it depends on how the absorbent article 8 is positioned on the user and may move while the user is wearing the diaper, hi order to increase the likelihood that this shape will be present in the product when the diaper is fitted to the wearer and to improve the stability of the desired shape during use, the diaper may be pre-folded in the side regions of the article and the folds may be fixed by the addition of fasteners. Thus, the bonding element may employ any combination of adhesives, thermal fusion bonding, ultrasonic bonding, or any other suitable method of bonding plastic and nonwoven-based materials. It is also conceivable: the fold-fix bond is achieved using a hook and loop engagement system or other non-permanent fixation means.

In some embodiments of the invention, a z-fold is formed in the leg wrap 18 of the diaper during manufacture. The leg wraps 18 may be folded towards the core and then secured in place using a suitable bonding method. Subsequently, the side panels are folded away from the core. Alternative bonding methods may be used to secure the fold in place. Figure 29 shows a section of a folded diaper with fold-and-fasten bond areas indicated by reference numeral 94. Bonded regions 94 are optional and embodiments of the present invention may not necessarily include bonded regions 94. Similarly, other embodiments of the present invention may include one or more bonded regions 94.

The bonding of the folded side regions can be achieved by applying the adhesive longitudinally continuously using any suitable application method, such as spiral spraying, intermittent crimping or continuous edge. Alternatively, continuous lines of ultrasonic or heat-fusion bonding may be used. Fig. 30 shows a schematic view of this embodiment.

In other embodiments of the invention, the longitudinal fold-and-secure bond may be discontinuous. The advantages are that: allows selection of the areas on the diaper where the fold can open to provide maximum void space while effectively locking the fold in place in other selected areas. In the embodiment of fig. 31, two fold-securing bonds on each side panel 18 are provided in the area near the front and back edges of the diaper. In another embodiment of fig. 32, the bond points are moved toward the center of the diaper. In another embodiment of fig. 33, one bond point for each side panel is provided in the central crotch region of the diaper.

The above schematic figures show possible variants of the folding bottom panel of the invention and possible locations for the folding-fastening joints. However, other embodiments of the invention not shown by the above figures are also possible. The position of the fold can be varied and it can be moved laterally to any position within the side panels or, alternatively, parts of the absorbent core can be introduced into the fold area. The number of fold-fixing bond points per side panel may also vary.

In addition to or instead of using the aforementioned fold-and-hold bond, providing a topsheet pitch that is narrower than the backsheet pitch ensures the retention characteristics of the void 84 and/or reservoir 26. In the preferred embodiment shown in fig. 34, the secondary topsheet 19 ensures that the desired voids and/or reservoirs are formed and maintained even in the event of changes in the donning or fit of the absorbent garment. The secondary topsheet 19 may also be additionally joined to the absorbent as shown in figure 35. In another embodiment shown in fig. 36, the first topsheet 10 may be folded and bonded to itself to form the void and/or reservoir. Figure 37 shows a partial length secondary topsheet 19 positioned around the center of the diaper. Other embodiments not shown in the figures are also possible. The positioning of the partial length secondary topsheet 19 can be optimized for optimal containment and separation of fecal exudates from the skin. Multiple secondary topsheets 19 are contemplated and optimally positioned for optimal fecal discharge management. In addition, the topsheet 19 may have apertures or holes to help collect liquid and solid exudates.

Importantly, the method comprises the following steps: the tension provided by the elastic side leg panel 18 cannot be too high or too low. If the tension provided by the side leg panels 18 is too low, the absorbent article 8 may not fit very tightly in certain areas around the legs and waist and the ability of the absorbent article to prevent leakage may be compromised. Higher tension may bind the user's thighs and cause an uncomfortable feeling. In typical prior art disposable absorbent articles, the positioning of the elastic members and the type of elastic members provided do not vary along the length of the extension panel. When stretched in a uniform manner, the overall stretch provided by the extension panel is also uniform along its length. However, when the absorbent article 8 is worn, the elongation of the leg wrap 18 along its length is generally non-uniform and, as a result, the resulting tension varies. As a result, there are undesirable areas of over-tightness or over-tightness around the length of the leg wrap 18.

In one aspect, the areas without elastic (e.g., the areas provided for the finger lift and landing zones) are also unique areas of elasticity formed by the predetermined arrangement of elastic. However, these regions of elasticity differ in that: structures suitable for use in the present invention are described in U.S. application Nos. 10/441, 469 entitled "DISPOSABLE ABSORBENT ARTICLE WITH ELASTICIZED SIDE PANELS ANDMETHOD OF MAKING SAME", which is hereby incorporated by reference and made a part OF this specification.

In addition, embodiments of the absorbent article 8 can provide improved comfort by positioning the elasticized side flaps closer to the side edges of the absorbent core 42. Thus, when initially positioned on a wearer, the elasticized side flaps are positioned in the groin areas along the inner thighs of the wearer to provide a better initial fit. This positioning provides a better initial fit on the wearer, since the elasticized side flaps of conventional diapers are generally initially positioned farther down the wearer's thighs and then tend to rise or creep into the groin areas of the wearer during use. As the side flaps are pulled upward, gaps tend to form in the legs and waist, making the wearer less comfortable. However, since the present invention initially locates the elastic leg wraps 18 in the groin area, diaper sagging is reduced, thereby enhancing wearer comfort.

The foregoing description has been presented for purposes of illustration and description. It should be emphasized that: the description should not be construed as limiting the invention to the various apparatus and methods described herein. The various aspects of the invention described above are applicable to other types of disposable absorbent articles and garments and methods for making such articles and garments. For example, the features of the elastic side panels with the fastening portions described above may be incorporated into other types of disposable absorbent articles (e.g., training pants). These variations of the present invention will be apparent to those skilled in the relevant consumer product arts or other related arts that may be provided with the present invention. Accordingly, many modifications and variations are possible in light of the above teaching, and it is desired to provide an improved method and apparatus for practicing the method and apparatus. The embodiments described and illustrated herein are further intended to explain the best modes known for practicing the invention and to enable others skilled in the art to utilize the invention and other embodiments and with various modifications required by the particular applications or uses of the present invention.

Claims (20)

1. A disposable absorbent article comprising:

an absorbent core disposed between a liquid pervious topsheet and a liquid impervious backsheet, longitudinally spaced from a first end edge of said article and a second end edge of said article, and disposed between a pair of laterally spaced side edges of said article;

a secondary topsheet; and

a pair of longitudinally extending flexible leg wraps disposed outwardly from and extending along the side margins of the absorbent core, each of the leg wraps comprising a plurality of spaced apart elastic strands separated from the absorbent core by inelastic zones, wherein the leg wraps and the absorbent core form a reservoir, and a plurality of fluid barriers are at least partially defined by the plurality of elastic strands during use of the absorbent article, and

wherein each flexible leg wrap includes a folded portion at least partially forming the reservoir,

wherein a bonded area of the secondary topsheet on the folded portion is bonded to each leg wrap and spans laterally between the leg wraps and through the reservoir during use to partially retain the reservoir.

2. The absorbent article of claim 1, wherein the absorbent core is positioned from 19mm to 64mm from the nearest elastic strand when the absorbent article is in a generally flat, open configuration, the number of elastic strands per side panel region is from 4 to 10, the distance between the individual elastic strands is from 4mm to 30mm, and wherein the distance between the individual elastic strands is from 6mm to 8 mm.

3. The absorbent article of claim 1 wherein the distance between the absorbent core and the nearest elastic strand is from 25mm to 40 mm.

4. The absorbent article of claim 1 wherein the inelastic zone is folded to define a portion of the reservoir.

5. The absorbent article of claim 4 wherein the partially inelastic zone is bonded together at one or more locations of the absorbent article.

6. The absorbent article of claim 1, wherein the distance between adjacent pairs of elastic strands is non-uniform such that the spacing of the elastic strands is not equal.

7. The absorbent article of claim 1, wherein the topsheet has regions of differing hydrophilic properties.

8. The absorbent article of claim 1 wherein the leg wraps include a first fold toward the core and a second fold away from the core.

9. The disposable absorbent article of claim 1,

the secondary topsheet spans a topsheet spacing that is narrower than the backsheet spacing, wherein a difference between the topsheet spacing and the backsheet spacing results in a reservoir being formed between the absorbent core and the wearer, the reservoir being capable of collecting bodily exudates.

10. The absorbent article of claim 9, wherein the secondary topsheet is disposed over the core, and wherein the reservoir is at least partially formed between the leg wraps by the leg wraps and the secondary topsheet.

11. The absorbent article of claim 1, wherein the secondary topsheet is disposed over the core, and wherein a void is formed by the leg wraps and the secondary topsheet at least partially between the leg wraps and between the core and the secondary topsheet.

12. The absorbent article of claim 1, wherein the secondary topsheet has a length that is shorter than the length of the secondary topsheet.

13. The absorbent article of claim 1, wherein a portion of the secondary topsheet is folded and bonded to itself.

14. The absorbent article of claim 1, wherein the secondary topsheet is bonded to the core at a location between the leg wraps.

15. The absorbent article of claim 1, wherein the lateral ends of the secondary topsheet are secured to the leg wraps.

16. The absorbent article of claim 15 wherein the distance between the central absorbent core and the elastic strands closest to the central body is from 10mm to 100mm and the distance between the elastic strands closest to the central body and the elastic strands furthest from the central body is greater than 38mm with the absorbent article provided in a flat open orientation.

17. The absorbent article of claim 15, wherein the distance between each elastic strand is from 6mm to 8 mm.

18. The absorbent article of claim 15 wherein the distance between the absorbent core and the nearest elastic strand is from 25mm to 40 mm.

19. The absorbent article of claim 1 wherein each flexible leg wrap includes a plurality of folded portions, the folded portions including inward folds and outward folds, the folded portions at least partially forming the reservoir.

20. The absorbent article of claim 1, wherein each flexible leg wrap comprises a z-fold that at least partially forms the reservoir with the secondary topsheet.