US20090124991A1 - Body Conforming Disposable Absorbent Article Having Leg Wraps and Internal Topsheet and Method of Making Same - Google Patents

Abstract

A secondary internal topsheet and leg wrap structure is provided in a disposable absorbent garment such as a diaper or training pants. The leg wrap structure has a base layer, a top layer, and an elastic construction disposed inbetween. The elastic construction includes a plurality of spaced apart elastic elements that are aligned in a generally in generally parallel relation. The leg wrap structure and secondary topsheet provides for the efficient formation of a reservoir and a plurality of fluid dams each capable of capturing a quantity of fluid to minimize the occurrence of fluid leaks from the absorbent article. Methods of forming such absorbent articles are disclosed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application claims priority under 35 U.S.C. 119(e) from provisional U.S. Patent Application No. 60/916,779 filed May 8, 2007 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 to contain liquid and a plurality of fluid dams further capable of retaining liquid to improve the overall containment characteristics of the absorbent article, especially the containment of loose fecal material.
BACKGROUND OF THE INVENTION
• Disposable absorbent articles are worn to contain and absorb urine and fecal exudates. To this end, an absorbent article incorporates certain improved components or structural attributes which function to provide a close, comfortable fit around the user's legs and waist. Such a close fit enhances the containment and leakage prevention capabilities of the absorbent article.
• Typical elements of disposal 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. Elasticized barrier leg cuffs, gathering components, and waistbands are often employed to provide leakage prevention by enhancing the fit of the absorbent article about the thighs and waist of the user. For example, elastic members may be positioned 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 threads or strands may be positioned laterally throughout the waist regions including side waist regions of the disposable absorbent article to allow the article to stretch during use. In this way, the article can stretch to accommodate variations of waist size and leg size of the 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 are intended to prevent body exudates from soiling, wetting, or otherwise contaminating clothing or other articles, such as bedding, that come in contact with the wearer. A limitation of such products is leakage out of the leg seals between the absorbent article and the wearer's leg or waist and onto adjacent clothing. This is most evident with loose fecal material which is not easily absorbed by the absorbent article and tends to freely flow on the top surface of the absorbent article.
• Contemporary disposable diapers have elasticized leg cuffs to improve both wearing comfort and the ability to contain body exudates. These elasticized leg cuffs prove somewhat effective to prevent wicking and overflow from a fluid laden absorbent article to clothing contacting the edges of the article in that the elasticized leg flaps present a fluid impervious barrier between the edge of the absorbent core and the contacting clothing, and in addition, provide for a sealing action about the legs of the wearer. Despite the effectiveness of such structures, however, body exudates, especially loose fecal material, can leak through the elasticized leg cuffs and soil the wearer's clothing because the diaper does not constrain the free flow of such material nor provide a structure to hold it within the diaper so that as such material flows along the top surface of the topsheet, it tends to work its way past the elasticized leg cuffs.
• Thus, it would be beneficial to provide an absorbent article designed to sustain the proper fit of the article around the legs of the wearer. If would be of further benefit to provide an absorbent article having a reduced possibility of leakage at the legs. It would also be beneficial to provide a reservoir that can constrain the flow of fecal material within the absorbent article to reduce the possibility of its leakage. Additionally, it would be of benefit to provide an absorbent article having easy application and/or removal and improved comfort for the wearer.
BRIEF SUMMARY OF THE INVENTION
• The present invention relates to a disposable absorbent article, such as a baby diaper or disposable pull-on garment, which includes a pair of elasticized leg wraps and internal secondary topsheet for effectively forming a reservoir within the absorbent article for preventing liquid and/or solid exudate leakage and providing better fit and aesthetic appearance. Embodiments of the present invention provide an absorbent article having improved liquid and exudate containment characteristics.
• Embodiment of the present invention includes a novel secondary topsheet that is incorporated into a disposable absorbent article and characterized by a narrowing of the distance between the pair of elasticized leg wraps when compared to the backsheet distance between the pair of elasticized leg wraps. The narrowing between the pair of elasticized leg wraps proximate to the secondary topsheet enhances the fit of the disposable absorbent article around the crotch region of the user. In particular, the difference between a topsheet gap and a backsheet gap allows the formation of a bucketing/reservoir effect. Different embodiments of this aspect of the invention are contemplated wherein the coversheet or topsheet(s) can be the primary or a secondary (i.e., additional) topsheet, be with or without holes or slits, be of full-length or partial length, be of a width that is less than, equal to or greater than the backsheet width, or be partially or fully glued down to itself to form a topsheet gap allowing the formation of the bucketing/reservoir effect. The details of these and other embodiments are described in the ensuing detailed description.
• In one aspect of the present invention, a disposable absorbent article has a central body and a pair of elasticized leg wraps. The central body includes an absorbent core and, thus, may be referred to herein as a central absorbent assembly. When disposed in a generally flat, open condition, e.g., before being worn by a user or at a later stage in the manufacturing process, the central body has or is otherwise further characterized by a front longitudinal edge, a rear longitudinal edge opposite the front longitudinal edge, and a longitudinal centerline extending across the front and rear edges. These front and rear edges define, at least partially, front and rear waist portions, respectively, of the disposable absorbent article. The pair of elasticized leg wraps extends longitudinally adjacent opposite lateral sides of the central body. Each leg wrap is spaced outwardly from the lateral edge of the absorbent core.
• In another aspect of the invention, leg wraps incorporated with or into the inventive disposable absorbent article may be characterized by an elastic stretch property or elasticity in the longitudinal direction. This elasticity is imparted to the leg wrap by an arrangement of elastic elements extending longitudinally along the disposable absorbent article. The elasticity of the leg wraps enhances the fit of the disposable absorbent article around the thighs of the user. In a particular embodiment, the elastic elements are parallel and spaced apart from each other, for example, by at least a few millimeters. In a preferred embodiment of the invention, the leg wrap provides an effective sealing function e.g., of a barrier leg cuff and leg gathers and fit function, for the disposable absorbent article.
• In yet another aspect of the invention, a method of manufacturing a disposable absorbent article is provided. The method includes providing a central body assembly 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 elements between the top and bottom layers.
• It is a further object of the present invention to provide an absorbent article having an internal secondary topsheet and improved elasticized leg wraps defining a plurality of fluid dams so as to provide a dual restraint against the lateral flow of body exudates, thereby improving the containment characteristics of the absorbent article, especially in regard to loose fecal material.
• Still other embodiments of the inventive disposable article and their manufacturing methods will become readily apparent to those skilled in the relevant art from the following detailed description of the drawings, wherein the various embodiments of the invention are described by way of illustrating the best mode contemplated for carrying out the invention. The invention is capable of other and different embodiments, its several details are capable of modification and its several structural or processed details are capable of modification in various and obvious respects, all without departing from the spirit and the scope of the present invention. Accordingly, the following drawings and detailed description of the drawings are to be regarded as illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a plan view of an inside face of a disposable absorbent article according to the present invention.
• FIG. 2 is a plan view of an inside face of a portion of the disposable absorbent article ofFIG. 1 in a generally flat, open condition.
• FIG. 3 is a plan view of the outside face of the disposable absorbent article ofFIG. 2.
• FIG. 4 is a cross-sectional view of the article ofFIGS. 2 and 3 along axis3-3.
• FIGS. 5 and 6 are alternate embodiments of an absorbent article in accordance with the present invention.
• FIG. 7 is a cross sectional view of an absorbent article according to the present invention.
• FIG. 8 is a plan view of an absorbent article of an embodiment of the present invention.
• FIGS. 9 to 24 are cross-sectional views of various embodiments of absorbent articles similar toFIGS. 2 and 3.
• FIG. 25 is a depiction of the application of an absorbent article of the present invention upon a wearer.
• FIGS. 26 and 27 are depictions of cross-sections taken through an absorbent article and wearer.
• FIG. 28 is a depiction of the absorbent article upon a wearer.
• FIG. 29 is a cross-sectional view illustrating a folded side panel concept in accordance with the present invention.
• FIGS. 30-31 illustrate different embodiments of securing the folded side panel in accordance with the present invention.
• FIG. 32-36 are cross-sectional views illustrating the formation of a narrower topsheet gap relative to the backsheet gap in accordance with the present invention.
• FIG. 37 illustrates a different embodiments of placing and attaching the topsheet in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
• As used herein, the term “disposable absorbent article” refers to articles which absorb and contain body exudates and more specifically refers 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, and 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, as indicated bynumeral8, is shown inFIG. 1. As used herein, the term “absorbent article” refers to a garment generally worn by infants and incontinent persons, which is worn about the lower torso of the wearer. It should be understood, however, that the present invention is also applicable for use in other disposable absorbent articles such as incontinent briefs and the like.
• FIG. 1 is a plan view of anabsorbent article8. Theabsorbent article8 comprises a liquid pervious topsheet orcoverstock10; a liquidimpervious backsheet12, anabsorbent core assembly14 disposed, for example, between thecoverstock10 and thebacksheet12; a pair offasteners16; flexible elastic leg wraps18;internal topsheet19; andelastic members20 secured within the leg wraps18 and capable of defining a plurality offluid dams90 when worn (as shown inFIG. 28). The liquidpervious coverstock10,absorbent core14,topsheet19 and liquidimpervious backsheet12 may be assembled in a variety of well known configurations as appreciated by those of ordinary skill in the art.
• FIGS. 2 and 3 are plan views of theabsorbent article8 of the present invention in the flat-out, uncontracted state (i.e., with all elastic induced contraction removed and prior to any folding operation performed on the article or addition of secondary topsheet19). The novelsecondary topsheet19 is not shown inFIGS. 2-24.FIG. 3 is a plan view of the other side (outer side) ofabsorbent article8 ofFIG. 2.
• Referring toFIGS. 2 and 3, theabsorbent article8 comprises a liquid pervious topsheet orcoverstock10; a liquidimpervious backsheet12, anabsorbent core assembly14 disposed, for example, between thecoverstock10 and thebacksheet12; a pair offasteners16; flexible elastic leg wraps18;elastic members20 secured within the leg wraps18 and capable of defining a plurality offluid dams90 when worn (as shown inFIG. 28). The liquidpervious coverstock10,absorbent core14 and liquidimpervious backsheet12 may be assembled in a variety of well known configurations as appreciated by those of ordinary skill in the art.
• FIGS. 2 and 3 illustrate an embodiment of theabsorbent article8 in which thecoverstock10 and thebacksheet12 are coextensive and have length and width dimension generally larger than those of theabsorbent core assembly14. Thecoverstock10 is superposed on thebacksheet12 thereby forming a periphery of theabsorbent article8 comprising end edges28 and30, andlongitudinal edges32 and34.
• Theabsorbent article8 haswaist regions36 and38 extending, respectively, from the end edges28 and30, of the absorbent article periphery toward thelateral centerline40 of the absorbent article8 a distance of from about ¼ to about ⅓ the length ofabsorbent article8. Thewaist regions36 and38 comprise those portions of theabsorbent article8 which, when worn, is positioned between the legs of the wearer and covers the lower torso of the wearer.
• Referring toFIG. 4, theabsorbent core assembly14 includes anabsorbent core42, a liquidpermeable nonwoven coverstock10 and a liquidimpermeable backsheet12. Additional layers of a material, such as additional absorbents, cellulose materials or nonwoven44, that provide additional functionality such as storage of urine, fast acquisition of urine and/or distribution of urine, may also be provided within the core assembly. Theabsorbent core42 may be composed of combinations of cellulose based absorbent materials, super-absorbent polymers, synthetic nonwoven materials or other absorbent materials. The disposable,absorbent article8 is joined together in such a way that thecoverstock10 andbacksheet materials12 entirely enclose theabsorbent core42. Thecoverstock10 andbacksheet12 may be directly joined together or indirectly joined together through an intermediate portion. Materials suitable for each of the core42,coverstock10 andbacksheet12 are generally known in the art.
• Thenonwoven coverstock10 provides a fluid permeable upper layer of the absorbent core assembly to contain the absorbent core components and allows the passage of body exudates into theabsorbent core42 during use. Preferably coverstock10 has length and width dimensions greater than that of theabsorbent core assembly42. These extended side edges of anonwoven coverstock10 may extend to the lateral edges32,34 of the absorbent article and serve to provide the upper layer of the composite containing theelastic members20. The lateral sides of anonwoven coverstock10, which extend over the elastic leg wraps18, may or may not be permeable to aqueous fluids.
• Thecoverstock10 is preferably compliant, soft feeling, and non-irritating to the wearer's skin. Further, thecoverstock10 is liquid pervious permitting liquids to readily penetrate through its thickness. A suitable coverstock may be manufactured from a wide range 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 from a combination of natural and synthetic fibers. Preferably, it is made of a hydrophobic material to isolate the wearer's skin from fluids in theabsorbent core42.
• A further embodiment of an absorbent article involves the use of a coverstock with zones of differing hydrophilic nature achieved by selective treatment of the material with agents which impart a hydrophilic nature to the nonwoven, e.g. surfactants. In this embodiment the coverstock will have a hydrophilic zone in the centre of the sheet, this central zone aligned to correspond with the region of the article where the absorbent core is disposed. The side zones, laterally adjacent to this central zone, may be less hydrophilic or more hydrophobic than the central zone. This produces an article having a hydrophilic, water permeable coverstock above the absorbent core to allow passage of urine into the core, and hydrophobic, water impermeable regions of said coverstock above the leg gathers to provide a dry feeling around the legs and to resist leakage of fluid through the leg wraps18.
• Leg wraps18 may include multipleelastic strands20 associated with eachside leg panel18. In one embodiment,elastic strands20 are sandwiched between thenonwoven coverstock10 and thebacksheet laminate12. The composite of theelastic strands20,nonwoven coverstock10 andbacksheet laminate12 is secured by using any suitable means familiar to those skilled in the art, such as adhesive bonding using slot coat or spray, spiral or swirl application of hot melt adhesive or ultrasonic bonding. In one embodiment sixelastic strands20 are shown perside leg panel18. Theelastic strands20 could be yarns of natural or synthetic rubber latex, or synthetic elastic materials such as spandex. The choice of elastic materials is not limited to elastic strands, but may also include ribbons of elastic materials, elastomeric films, elastic scrims, elastic and nonwoven composites and the like.
• FIG. 4 is a cross-sectional view of the embodiment ofFIG. 2 andFIG. 3 wherein thebacksheet material12 is represented as a laminate of an air porous or air non-porous, fluid impermeable, polyethylene orpolypropylene film52 and a fluidimpermeable polypropylene nonwoven54. Such materials are known to those skilled in the art as clothlike or textile backsheet. It is also suggested that thebacksheet material12 can be a single layer of polyethylene film or other suitable composite material.
• Thefasteners16 may involve pressure sensitive adhesive fastening tapes which secure to a frontal portion of silicone, “release” coated polyolefin film, hook and loop tapes or any other suitable fastening medium. The absorbent article may also have an elasticized waistband using an elastic foam, elastic film, elastic strands or other suitable elastic, elastic laminate, stretchable material affixed to or between the coverstock and backsheet portions.
• An example of the disposable absorbent article according to the present invention provides a close fitting seal around the thighs of the user, thereby significantly improving its leakage prevention capability. The close fitting seal of the inventive garment is further enhanced through addition offastening element16. Thefastening element16 may be provided by known adhesive elements or hook fastening devices. The hook fastening element may be selected so as to be engageable with the loops formed on the surface of a nonwoven fabric. Thus, the nonwoven material of the stretchband panel provides the loop element of a hook and loop fastening system similar to those generally known in the art.
• In further embodiments, a loop landing tape may be located near the front waist region of the outside face of the inventive article, and a pair of hook fastening elements may be located in the rear non-elasticized zones of each stretch panel. The fastening portion is therefore attached directly to the central body rather than to the front edge of the stretch panel. The loop landing tape may be constructed from a knitted, extruded, or non-woven material, as is generally known in the art.
• FIGS. 5 and 6 show various other embodiments ofabsorbent articles8.FIG. 5 shows an alternative embodiment where the lateral side edges32,34 of theabsorbent article8 are inwardly curved to define cut-outregions56. This shaped product facilitates a better fit of the product around the waist of the wearer without increasing the amount of material within the side panel that would be gathered around the user's legs when worn.
• FIG. 5 discloseselastic elements20 which are oriented parallel to at least a portion of the lateral side edges32,34 of theabsorbent article8. In comparison,FIG. 6 depictselastic elements20 which follow the inwardly curved side portions of the absorbent article. Descriptions of some additional configurations suitable for use with the present invention are found in U.S. Ser. No. 11/295,781, entitled “Disposable Absorbent Article Having Leg Wraps and Method of Making Same”, hereby incorporated by reference and made a part of the present disclosure.
• Additional concepts of the present are disclosed inFIG. 6 wherein theabsorbent article8 is defined by a centralabsorbent core assembly14 and a pair of leg wraps18 separated from theabsorbent core assembly14 by inelastic regions orzones58 of substantially decreasedelasticity58. Eachinelastic zone58 is defined between theabsorbent core assembly14 and the nearestelastic strand member20 of the leg wraps18.
• Referring toFIG. 7, a distance, h, is defined between the lateral edges of theabsorbent core assembly14 and theelastic strand20 nearest to thecore assembly14 or stated another way, thestrand20 furthest from the lateral edges32,34 of theabsorbent article8. The spacing between thestrands20 of elastic material is represented as distance, e.
• FIG. 8 also illustrates another embodiment of thefasteners16 which may be utilized in the practice of the invention.Fasteners16 may be provided on the outward portion ofside panels35 having one or more regions ofelasticity37 and one or more regions ofinelasticity39. Other fasteners and side panel constructions are disclosed in U.S. Ser. No. 11/113,114, entitled “Extensible Side Panels For Use With Convertible Absorbent Articles”, hereby incorporated by reference and made a part of the present disclosure.
• In preferred embodiments of the present invention, thestrand20 count for eachelastic leg wrap18 ranges from 4 to 10 strands, and more preferably between 4 to 6 strands. The distance, h, (width of inelastic zone58) is preferably between 19 mm to 64 mm, and more preferably between 25 mm to 40 mm. The distance, e, between thestrands20 is preferably between 4 mm to 40 mm, more preferably greater than 6 mm, and yet more preferably approximately 8 mm.
• Leg cuff elements64 may be provided upon a top surface of thecoverstock10 of anabsorbent article8.Leg cuff elements64 may be defined by material of thecoverstock layer10, or may be of different material attached in know manners to the top surface. The construction ofleg cuff elements64 within theabsorbent article8 would be understood by those of ordinary skill in the art. As depicted inFIGS. 9-13,leg cuff elements64 may be provided at different distances away fromabsorbent core14.
• FIGS. 9-24 show cross sections of alternate embodiments of the topsheet, backsheet and absorbent article suitable for use with the internal topsheet19 (not shown). In some embodiments, the continuous fullwidth nonwoven coverstock10 may be replaced with a three-piece construction. In thecentral region10 of the absorbent article amaterial66 permeable to aqueous fluids such as a hydrophilic treated polypropylene nonwoven is placed over the absorbent core to contain the absorbent materials and to allow the passage of urine into theabsorbent core14. Anothermaterial element68 forms the top layer of theelastic side panels18 along each lateral side edge of the article. This material may be selected from suitable materials such as water permeable polypropylene nonwovens, water impermeable polypropylene nonwovens, polyethylene film and the like.FIG. 9 shows the absorbentcore covering material66 overlapping the outer elasticcomposite covering material68.FIG. 10 shows the absorbentcore covering material66 under-lapping thematerial68 covering the elastic composite.
• In the embodiment ofFIG. 11, anabsorbent core assembly42 is enclosed by a nonwoven, fluidpermeable coverstock70 and a fluidimpermeable backsheet72. In this embodiment thecoverstock70 andbacksheet72 do not extend to the outer edges of the absorbent article. A single ply ofnonwoven web74 is folded around and encloses theelastic strands20. This elastic composite is then attached to the sides of theabsorbent core assembly14 using any suitable means, for example using hotmelt adhesives or ultrasonic bonding.
• In the example ofFIG. 12, thecoverstock material10 extends continuously over the full width of theabsorbent article8, as is the case in the first embodiment of the invention. In this embodiment a separate piece ofsuitable material78 is used to enclose the underside of elastic composite on eachleg wrap18.
• FIG. 13 shows an alternate embodiment to that shown inFIG. 11. This embodiment differs in that two separate layers of suitable material are used to enclose theelastic strand elements20 within elastic composite elements which are affixed between the coverstock and backsheet portions of thecore assembly14.
• FIGS. 14-24 show still further embodiments where the underside of the elastic composite side panels are formed from a material such as the fluid impermeable polypropylene nonwoven which extends continuously across the full width of the absorbent article.
• FIGS. 25-28 depict a disposable absorbent article as fitted to the wearer. The novelinternal topsheet19 is shown in these figures. Theabsorbent article8 folds inwards atpoint80 and outwards atpoint82. Theabsorbent article8 may naturally conform to the shape depicted inFIGS. 25-28. It may be necessary or useful to prefix the article in this configuration by applying spots of adhesive or by using any other suitable means to ensure that the article is fitted correctly to the wearer.
• The outcome of this folding pattern of the article is two fold. First, the elastic leg wraps18 are desirably positioned against the wearer's body and fit securely around the upper thighs and buttocks of the user. This serves to create a generally fluid impermeable seal around the legs, crotch and thighs of the user, which reduces the incidence of leakage. Second, theabsorbent core assembly14 is held away from the body of the wearer, particularly in the crotch area of the article. This serves to create avoid space84 between the user's body and theabsorbent core assembly14.
• Thisvoid space84 may have an approximately trapezoid appearance as demonstrated inFIG. 26, with a base having a length approximately equal to the width of theabsorbent core42, sides of a length approximately equal to dimension X, and a top length dependent upon the angle formed between the base and sides. Portions of thearticle8 can pivot or rotate relative to each other so that theabsorbent core42 and leg wraps18 can freely move upon the wearer. This pivoting effect enables the leg wraps18 to move during use while maintaining an effective leg seal.
• Void space84 created by the structure of theabsorbent article8 serves to hold theabsorbent core42 away from direct contact with the skin or body of the wearer. For example, rewet or the wetting of the user's skin by body waste fluids not completely captured by the superabsorbent materials within theabsorbent core42 is reduced, resulting in improved comfort for the wearer.
• Referring particularly toFIGS. 25 and 28,reservoir26 is a structure in which body exudates can be collected, contained and held. Exudates float or flow along the top surface flow into and down the side walls of thereservoir26 to be collected in the bottom of thereservoir26 until theabsorbent article8 can be removed. Thereservoir26 is, therefore, especially effective for exudates, particularly loose fecal materials, that are not easily absorbed by theabsorbent core14 and tend to “float” on thecoverstock10.
• Thereservoir26 may be disposed at least in part between theelastic members20 and the longitudinal centerline of theabsorbent article8, e.g., by material within the zone of decreasedelasticity58. Thereservoir26 may be constructed of materials known in the art which are compliant and conformable enough to present a pocket or well-like shape. The material may be absorbent, wicking or impermeable to exudates. For example, thereservoir26 may comprise an element (i.e., thecoverstock10, thebacksheet12 or the leg wrap18) or any combination of these elements or other elements of theabsorbent article8 configured or folded to present a reservoir. In addition, thereservoir26 may have a variety of shapes and cross-sections provided that a pocket or well-like shape is formed to contain and hold the exudates. For example, thereservoir26 may have a semi-circular, square or parabolic cross-section. Preferably, thereservoir26 is formed by folding material within the zone of decreasedelasticity58 and securing the folded portion to portions of thecoverstock10 adjacent theabsorbent core14.
• FIG. 28 illustrates thetemporary reservoir26 and void84 wherein thereservoir26 contains fluid prior to absorption bycore14. Fluid is prevented from passing throughside leg panels18 by the series of elastic gathers defining a plurality of fluid dams as indicated bynumeral90. Fluid which passes through one of thefluid dams90 encounters the furtherly-outward fluid dam90. As a result, multiple sealing structures are provided by the leg wraps18.
• It has been found that the desired trapezoid shape ofvoid84 and/orreservoir26 can be difficult to form and maintain in every application as it can be dependent on how theabsorbent article8 is placed on the user and movements the user might make whilst wearing the diaper. In order to improve the likelihood that this shape exists in the product when the diaper is fitted to the wearer and to improve the stability of the desired shape during use it is possible to pre-fold the diaper in the side regions of the product, and fix the fold with the addition of a bonding element. This bonding element could be any combination of adhesive, thermo-bonding, ultrasonic bonding or any other suitable method of bonding plastic and nonwoven based materials. It is also envisaged that this fold-fixing bond point could also be obtained using a hook and loop engagement system or other non-permanent fixation means.
• In some embodiments of the present invention a z-shaped fold is formed in theleg wrap18 of the diaper during manufacture. The leg wraps18 can be folded in towards the core and a suitable bonding method is then used to fix this fold in position. Secondly, the side panel is then folded back away from the core. An optional bonding method can be used to fix this fold in position.FIG. 29 shows a cross-section of the folded diaper with the fold-fixing bonded areas indicated asnumeral94.Bonded areas94 are optional and embodiments of the present invention may not necessarily include bondedareas94. Similarly, other embodiments of the present invention may include one or more bondedareas94.
• Bonding of the folded side region can be achieved by a longitudinally continuous application of adhesive using any suitable application method, such as spiral spray, intermittent bead or continuous bead. Alternatively a continuous line of an ultrasonic or thermal bonding method could be used.FIG. 30 shows a diagram of this embodiment.
• In further embodiments of this invention the longitudinal fold-fixing bonding points can be discontinuous. This has the advantage of allowing selection of zones on the diaper where the fold can open up to provide maximum void space, whilst effectively pinning the fold in position in other selected areas. In the embodiment ofFIG. 31, two fold fixing bond points perside panel18 are provided in a region close to the front and rear edges of the diaper. In another embodiment ofFIG. 32 these bond points are moved towards the center of the diaper. In yet another embodiment ofFIG. 33, a single bond point per side panel is provided in the center crotch region of the diaper.
• The diagrams above show possible variations of the folded chassis of this invention and the possible positions for fold-fixing bond points. However further embodiments of this invention not shown by the drawings above are also possible. The position of the fold is variable and could be moved laterally to any position within the side panel or, alternatively, sections of the absorbent core could be incorporated into the folded region. The number of fold-fixing bond points per side panel is also variable.
• In addition to or in place of the use of the aforementioned fold-fixing bond points, providing a topsheet gap that is narrower than the back sheet gap can assure the maintenance ofvoid84 and/orreservoir26. In a preferred embodiment illustrated inFIG. 34,secondary topsheet19 ensures that the preferred void and/or reservoir is created and maintained even with variations in donning or fitting of the absorbent garment. Thesecondary topsheet19 may also be additionally bonded to the absorbent as illustrated inFIG. 35. In another embodiment shown inFIG. 36, theprimary topsheet10 can be folded and bonded to itself to create the void and/or reservoir.FIG. 37 shows a partial lengthsecondary topsheet19 placed about the center of the diaper. Further embodiments not shown by the drawings are also possible. The positioning of thepartial length topsheet19 can be optimized for best performance in relation to the containment of fecal exudates and its separation from the skin. A plurality oftopsheets19 can also be envisioned and optimally positioned for best performance in fecal exudates handling. Additionally, topsheet19 can have slits or holes to assist in the capture of liquid and solid exudates.
• It is important that the tension forces provided by the elasticizedside leg panel18 are neither too low nor too high. If the tension forces provided by theside leg panel18 are too low, theabsorbent article8 may not fit very closely in certain regions around the legs and the waist and the absorbent article ability to prevent leakage will be compromised. High tension forces may constrict the user's thighs and cause discomfort. In a typical prior art disposable absorbent article, the positioning of elastomeric elements and the type of elastomeric element placed does not vary along the length of the stretch panel. The elasticity or elastication of the stretch panel is, therefore, uniform along the stretch panel length. When elongated in a uniform manner, the overall tension provided by the stretch panel is also uniform along its length. The magnitude of this uniform tension depends on the overall elongation of the leg wraps18. When theabsorbent article8 is worn, however, the elongation of theleg wrap18 along it length is generally non-uniform, and thus, the tension generated varies. As a result, there may be regions about the length of theleg wrap18 that are undesirably too loose or too tight.
• In one respect, regions or zones devoid of elastic elements—e.g., zones provided for finger lift area and landing area—are also distinct regions of elasticity formed by pre-determined placement of elastic elements. These regions of elasticity differ, however, in the sense that the elastic elements do not impart elasticity to the stretch panel in these regions in contrast to the distinct regions of imparted elasticity in the vicinity of the elastic elements. Descriptions of some configurations suitable for use with the present invention are found in U.S. Ser. No. 10/441,469, entitled “Disposable Absorbent Article With Elasticized Side Panels and Method of Making Same”, hereby incorporated by reference and made a part of the present disclosure.
• In addition, embodiments of theabsorbent article8 achieve increased comfort by positioning the elasticized side flaps closer to the side edge of theabsorbent core42. Thus, when initially placed on the wearer, the elasticized side flaps ride in the groin areas along the inner thighs of the wearer thereby providing a better initial fit. This positioning provides a better initial fit on the wearer because elasticized side flaps of conventional diapers are often initially positioned farther down on the thigh of the wearer and subsequently tend to ride or creep up into the groin regions of the wearer during use. Because the side flaps are drawn up, gaps tend to form in the legs and waist providing less comfort for the wearer. However, because the present invention initially positions the elasticized leg wraps18 in the groin areas, sagging of the diaper is reduced resulting in increased comfort for the wearer.
• The foregoing description of the present invention has been presented for purposes of illustration and description. It is to be noted that the description is not intended to limit the invention to the various apparatus and processes disclosed herein. Various aspects of the invention as described above, may be applicable to other types of disposable absorbent articles and garments, and processes for making the same. For example, the feature of an elasticized side panel having the fastening portion described above, may be incorporated in other disposable absorbent articles such as training pants, etc. Moreover, the feature of an elasticized side panel as having the characteristic elasticity described above may also be incorporated in other disposable absorbent articles and garments. Such variations of the invention will become apparent to one skilled in the relevant consumer products, or other relevant art provided with the present disclosure. Consequently, variations and modifications commensurate with the above teachings, and the skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described and illustrated herein are further intended to explain the best modes 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 top sheet and a liquid impervious back sheet;

a topsheet spanning an internal topsheet gap that is narrower than a backsheet gap wherein a difference between the topsheet gap and the backsheet gap results in formation of a reservoir between the absorbent core and a wearer, said reservoir adapted to capture bodily exudates; and

a pair of flexible leg wraps extending outwardly from and along side edges of said absorbent core, said leg wraps each including a plurality of spaced-apart elastic strands separated from the absorbent core by an inelastic zone, wherein the leg wraps and absorbent core form the reservoir and a plurality of fluid dams are defined at least in part by the plurality of elastic strands during use of the absorbent article, with each fluid dam capable of capturing a volume of liquid waste from passing between the leg wrap and the wearer.

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

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

4. The absorbent article ofclaim 1 wherein the inelastic zone is capable of being folded over to define portions of the reservoir.

5. The absorbent article ofclaim 4 wherein portions of the inelastic zone are adhered together in one or more locations of the absorbent article.

6. The absorbent article ofclaim 1 wherein a distance between adjacent pairs of elastic strand is nonuniform so that the elastic strands are not equally spaced apart.

7. The absorbent article ofclaim 1 wherein the top sheet has zones of differing hydrophilic properties.

8. The absorbent article ofclaim 6 wherein the elastic strands are provided with a plurality of different diameters.

9. A disposable absorbent article comprising:

an absorbent core being disposed between a liquid pervious top sheet and a liquid impervious back sheet;

a top sheet spanning a topsheet gap that is narrower than a backsheet gap wherein a difference between the topsheet gap and the backsheet gap results in formation of a reservoir between the absorbent core and a wearer that is capable of capturing bodily exudates; and

a pair of elasticized leg wraps extending longitudinally adjacent opposite lateral sides of said absorbent core, said leg wraps including a plurality of spaced-apart elastic strands, wherein the reservoir is defined between the absorbent core and folded portions of the leg wrap during use, and a plurality of fluid dams are defined in part by the plurality of spaced-apart elastic strands during use, with each of the plurality of fluid dams capable of retaining a fluid volume against leakage from the leg wraps.

10. The absorbent article ofclaim 9 wherein with the absorbent article provided in a generally flat, opened orientation, the distance between the absorbent core and the nearest strand of elastic is between 25 mm to 51 mm, the number of elastic strands is between 5 and 10, and the distance between the individual strands is between 5 mm to 10 mm and wherein the distance between the central absorbent core and the nearest strand of elastic is between 30 mm to 44 mm.

11. The absorbent article ofclaim 9 wherein the number of elastic strands is between 6 and 8 strands.

12. The absorbent article ofclaim 9 wherein the distance between the individual strands is between 6 mm to 9 mm.

13. The absorbent article ofclaim 9 wherein the distance between the absorbent core and the nearest elastic strand is between 10 mm to 100 mm.

14. The absorbent article ofclaim 13 wherein the distance between the absorbent core and the nearest elastic strand is between 42 mm to 50 mm.

15. A method of making a disposable absorbent article method comprising:

providing a central body with an absorbent core;

forming a topsheet gap that is narrower than the backsheet gap;

spanning the topsheet gap with a topsheet;

securing lateral ends of the topsheet to the central body; and

providing a pair of elasticized leg wraps extending longitudinally adjacent opposite lateral sides of said central body, each said leg wrap having a plurality of elastic strands extending generally along a longitudinal direction of the absorbent article.

16. The method ofclaim 15 wherein with the absorbent article provided in a flat, opened orientation, the distance between the central absorbent core and the elastic strand nearest to the central body is between 10 mm to 100 mm, and the spacing between said elastic strand nearest to the central body and the elastic strand furthest from the central body is greater than 38 mm.

17. The method ofclaim 15 wherein the distance between individual elastic strands is between 6 mm to 8 mm.

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

19. The method ofclaim 16 wherein the inelastic zone is capable of being folded over to define portions of the reservoir.

20. The method ofclaim 19 wherein portions of the inelastic zone are adhered together in one or more locations of the absorbent article.

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