US20070173780A1 - Disposable absorbent article having backsheet strips - Google Patents

Abstract

A disposable absorbent article includes two laterally opposing longitudinally extending backsheet strips attached to an exterior surface of an absorbent assembly in laterally opposing attachment zones. Each backsheet strip may include a water-impermeable layer and may be extensible. The absorbent assembly includes laterally opposing side flaps which may be formed by folding portions of the absorbent assembly laterally inward. A longitudinally extending elastic gathering member is attached to each side flap adjacent to its proximal edge. When the article is worn, the elastic gathering members contract and raise the side flaps to form side barriers. The absorbent assembly includes an absorbent core that may contain superabsorbent particles, which may be contained inside pockets. A portion of the absorbent assembly such as the portion that lies between the backsheet strip attachment zones may be extensible and may include a water-impermeable layer.

Description

CROSS-REFERENCE TO RELATED APPLICATION
• This application is a division of co-pending application Ser. No. 11/172,191 filed on 30 Jun. 2005, which is a continuation of application Ser. No. 10/880,135 filed on 29 Jun. 2004, now U.S. Pat. No. 6,962,578 issued on 8 Nov. 2005.
FIELD OF THE INVENTION
• This invention relates to disposable absorbent articles such as disposable diapers and other articles intended for use on incontinent persons.
BACKGROUND OF THE INVENTION
• Disposable absorbent articles are designed to absorb and contain bodily waste in order to prevent soiling of the body and clothing of the wearer, as well as bedding or other objects with which the wearer comes into contact. As the usage of disposable absorbent articles has expanded, their complexity has increased with the incorporation of additional features serving to enhance their performance and appearance. The costs of the materials and the costs of the manufacturing processes have also increased in conjunction with the increase in complexity. As a result, the prices at which these articles are sold have risen to levels that many potential purchasers around the world cannot afford to pay. Thus, a need exists for a simple disposable absorbent article.
SUMMARY OF THE INVENTION
• The present invention provides a disposable absorbent article including two laterally opposing longitudinally extending backsheet strips attached to an exterior surface of an absorbent assembly in laterally opposing attachment zones. Each backsheet strip may include a water-impermeable layer and may be extensible. The absorbent assembly includes laterally opposing side flaps which may be formed by folding portions of the absorbent assembly laterally inward. A longitudinally extending elastic gathering member is attached to each side flap adjacent to its proximal edge. When the article is worn, the elastic gathering members contract and raise the side flaps to form side barriers. The absorbent assembly includes an absorbent core that may contain superabsorbent particles, which may be contained inside pockets. A portion of the absorbent assembly such as the portion that lies between the backsheet strip attachment zones may be extensible and may include a water-impermeable layer.
BRIEF DESCRIPTION OF THE DRAWINGS
• In the accompanying drawing figures, like reference numerals identify structurally corresponding elements, which may or may not be identical in the several exemplary embodiments that are depicted. Some of the figures may have been simplified by the omission of selected elements for the purpose of more clearly showing other elements. Such omissions of elements in some figures are not necessarily indicative of the presence or absence of particular elements in any of the exemplary embodiments, except as may be explicitly delineated in the corresponding written description.
• In the drawing figures and in the written description, lowercase letters appended to reference numerals indicate generally symmetric elements, e.g., the left and right side edges of theabsorbent assembly200 are respectively identified by thereference numerals237aand237b. A reference numeral without an appended lowercase letter identifies all of the elements to which that particular reference numeral applies, e.g., the same side edges as a group are designated237.
• FIG. 1 is a plan view of an exemplary disposable absorbent article in the form of adiaper20, which is shown in its flat, uncontracted state, i.e., without the contraction induced by elastic members. InFIG. 1, the interior portion of thediaper20 that faces inwardly toward the wearer and contacts the wearer is shown facing the viewer.
• FIG. 2 is a plan view of thediaper20 ofFIG. 1 in its flat, uncontracted state, with the exterior portion of thediaper20 that faces outwardly away from the wearer shown facing the viewer.
• FIG. 3,FIG. 4, andFIG. 5 are section views of thediaper20 ofFIG. 1 andFIG. 2 taken at the respective section lines3-3,4-4, and5-5. In these section views, the interior portion of thediaper20 that faces inwardly toward the wearer and contacts the wearer is shown facing upward.
• FIG. 6 is a simplified side elevation view of anexemplary diaper20 being worn about a lower torso of a wearer.
• FIG. 7 is a front elevation view of thediaper20 ofFIG. 6 being worn about the lower torso of the wearer.
• FIG. 8 is a back elevation view of thediaper20 ofFIG. 6 being worn about the lower torso of the wearer.
• FIG. 9 is a plan view of an exemplary fragment of a formed web material.
• FIG. 10 is a simplified left side elevation view of anexemplary diaper20 including cohesive fastening patches being worn about a lower torso of a wearer.
• FIG. 11 is a simplified right side elevation view of thediaper20 ofFIG. 10 including cohesive fastening patches being worn about the lower torso of the wearer.
• FIG. 12 is a simplified plan view of another exemplary disposable absorbent article in the form of adiaper20, which is shown in its flat, uncontracted state and with its interior portion facing the viewer.
• FIG. 13 is a simplified plan view of thediaper20 ofFIG. 12 with its exterior portion facing the viewer.
• FIG. 14 is a perspective view of anexemplary diaper20, which is shown in its relaxed, contracted state and with its interior portion facing upward.
• FIG. 15 is a plan view of an exemplaryabsorbent assembly200, shown separately from the other portions of an exemplary diaper and with its interior portion facing the viewer.
• FIG. 16 is a section view of the absorbent assembly ofFIG. 15 taken at the section line16-16.
• FIG. 17 is a section view of the absorbent assembly ofFIG. 15 taken at the section line17-17.
• FIG. 18 is a section view of an exemplaryabsorbent assembly200 showing details of an exemplary absorbent core having particles of superabsorbent material contained inside pockets
• FIG. 19 is a section view of an exemplaryabsorbent assembly200 having anadditional bottom sheet226, taken at a section line corresponding to the section line4-4 inFIG. 1.
• FIG. 20 is a plan view of another exemplary disposable absorbent article in the form of adiaper20, which is shown in its flat, uncontracted state and with its interior portion facing the viewer.
• FIG. 21 is a plan view of another exemplary disposable absorbent article in the form of adiaper20, which is shown in its flat, uncontracted state and with its interior portion facing the viewer.
• FIG. 22 is a plan view of thediaper20 ofFIG. 21 in its flat, uncontracted state, with its exterior portion facing the viewer.
• FIG. 23 is a section view of thediaper20 ofFIG. 21 andFIG. 22 taken at the section line23-23, with its interior portion facing upward.
• FIG. 24 is a plan view of another exemplary disposable absorbent article in the form of adiaper20, which is shown in its flat, uncontracted state and with its interior portion facing the viewer.
DETAILED DESCRIPTION OF THE INVENTION
• In this description, the following terms have the following meanings:
• The term “absorbent article” refers to a device that absorbs and contains liquid, and more specifically, refers to a device that is placed against or in proximity to the body of the wearer to absorb and contain the various exudates discharged from the body.
• The term “diaper” refers to an absorbent article that is generally worn by infants and incontinent persons about the lower torso so as to encircle the waist and the legs of the wearer and that is specifically adapted to receive and contain urinary and fecal waste.
• The term “disposable” refers to the nature of absorbent articles that generally are not intended to be laundered or otherwise restored or reused as an absorbent article, i.e., they are intended to be discarded after a single use and, preferably, to be recycled, composted or otherwise disposed of in an environmentally compatible manner.
• The term “longitudinal” refers to a direction running from a waist edge to an opposing waist edge of the article and generally parallel to the maximum linear dimension of the article. Directions within ±45° of the longitudinal direction are considered to be “longitudinal”.
• The term “lateral” refers to a direction running from a side edge to an opposing side edge of the article and generally at a right angle to the longitudinal direction. Directions within ±45° of the lateral direction are considered to be “lateral”.
• The term “disposed” refers to an element being attached and positioned in a particular place or position in a unitary structure with other elements.
• The term “attached” refers to elements being connected or united by fastening, adhering, bonding, etc. by any method suitable for the elements being attached together and their constituent materials. Many suitable methods for attaching elements together are well-known, including adhesive bonding, pressure bonding, thermal bonding, mechanical fastening, etc. Such attachment methods may be used to attach elements together over a particular area either continuously or intermittently.
• The term “cohesive” refers to the property of a material that, once set, sticks to itself but does not to any significant degree stick to other materials.
• The terms “water-permeable” and “water-impermeable” refer to the penetrability of materials in the context of the intended usage of disposable absorbent articles. Specifically, the term “water-permeable” refers to a layer or a layered structure having pores, openings, and/or interconnected void spaces that permit liquid water to pass through its thickness in the absence of a forcing pressure. Conversely, the term “water-impermeable” refers to a layer or a layered structure through the thickness of which liquid water cannot pass in the absence of a forcing pressure. A layer or a layered structure that is water-impermeable according to this definition may be permeable to water vapor, i.e., may be “water vapor-permeable”. Such a water vapor-permeable layer or layered structure is commonly known in the art as “breathable”. As is well known in the art, a common method for measuring the permeability to water of the materials typically used in absorbent articles is a hydrostatic pressure test, also called a hydrostatic head test or simply a “hydrohead” test. Suitable well known compendial methods for hydrohead testing are approved by INDA (formerly the International Nonwovens and Disposables Association, now The Association of the Nonwoven Fabrics Industry) and EDANA (European Disposables And Nonwovens Association).
• The terms “proximal” and “distal” refer respectively to the location of an element relatively near to or far from the center of a structure, e.g., the proximal edge of a longitudinally extending element is located nearer to the longitudinal axis than the distal edge of the same element is located relative to the same longitudinal axis.
• The terms “interior” and “exterior” refer respectively to the location of an element that is intended to be placed against or toward the body of a wearer when an absorbent article is worn and the location of an element that is intended to be placed against or toward any clothing that is worn over the absorbent article. Synonyms for “interior” and “exterior” include, respectively, “inner” and “outer”, as well as “inside” and “outside”. Also, when the absorbent article is oriented such that its interior faces upward, e.g., when it is laid out in preparation for setting the wearer on top of it, synonyms include “upper” and “lower” and “top” and “bottom”, respectively.
• Description of Exemplary Diaper Embodiments
• As shown inFIG. 1,FIG. 2,FIG. 3,FIG. 4, andFIG. 5, one end portion of theexemplary diaper20 is configured as afront waist region36, the longitudinally opposing end portion is configured as aback waist region38, and an intermediate portion is configured as acrotch region37.
• The basic structure of thediaper20 includes anabsorbent assembly200, which has afront edge236, aback edge238, aleft side edge237a, aright side edge237b, aninterior surface202, and anexterior surface204. Alongitudinal axis42 extends through the midpoints of thefront edge236 and theback edge238 and alateral axis44 extends through the midpoints of theleft side edge237aand theright side edge237b. Theabsorbent assembly200 has laterally opposing side flaps247aand247bthat are described in more detail below.
• The basic structure of thediaper20 also includes two laterally opposing longitudinally extending backsheet strips designated theleft backsheet strip100aand theright backsheet strip100b. The backsheet strips have respective leftfront waist edge136aand rightfront waist edge136b, left backwaist edge138aand rightback waist edge138b, left stripproximal edge156aand right stripproximal edge156b, leftinterior surface102aand rightinterior surface102b, leftexterior surface104aand rightexterior surface104b. The two backsheet strips100 extend laterally beyond the side edges237 of theabsorbent assembly200 and thereby define aleft side edge137aand aright side edge137bof thediaper20.
• As shown inFIG. 2,FIG. 3,FIG. 4, andFIG. 5, the backsheet strips100aand100band thelower covering sheet25 of theabsorbent assembly200 are attached together in laterally opposing longitudinally extending attachment zones such as theexemplary attachment zones220aand220b.
• As shown inFIG. 6,FIG. 7, andFIG. 8, when thediaper20 is worn on the lower torso of a wearer, the front waist edges136aand136bof the backsheet strips, thefront edge236 of the absorbent assembly, the back waist edges138aand138bof the backsheet strips, and theback edge238 of the absorbent assembly encircle the waist of the wearer, the side edges137aand137bencircle the legs of the wearer, thecrotch region37 is generally positioned between the legs of the wearer, and theabsorbent assembly200 extends from thefront waist region36 through thecrotch region37 to theback waist region38.
• A portion or the whole of each of the backsheet strips may be formed of an elastically extensible material or materials. Alternatively, or in addition, a portion or the whole of each of the backsheet strips may be made extensible to a degree greater than the inherent extensibility of the material or materials from which the backsheet strip is made. Similarly, a portion or the whole of the absorbent assembly may be formed of an elastically extensible material or materials. Alternatively or in addition, a portion or the whole of the absorbent assembly may be made extensible to a degree greater than the inherent extensibility of the material or materials from which the absorbent assembly is made. The additional extensibility may be desirable in order to allow thediaper20 to conform to the body of a wearer during movement by the wearer. Additional lateral extensibility may be particularly desirable to allow the user of a diaper to extend the front waist region and/or the back waist region to encircle the waist of a wearer, i.e., to tailor the waist size and fit of a diaper to the individual wearer. Such a lateral extension of the waist region or regions may give the diaper a generally hourglass shape and may impart a tailored appearance to the diaper when it is worn. In addition, the additional extensibility may be desirable in order to minimize the cost of the diaper, because a relatively lesser amount of material is needed when the material is made extensible as described.
• For the purpose of fitting to the waist of the wearer, in some embodiments additional lateral extensibility in theabsorbent assembly200 is provided only between the laterally opposingattachment zones220aand220bwhere theabsorbent assembly200 and the backsheet strips100aand100bare attached together, rather than in the entire absorbent assembly.
• Additional extensibility in the backsheet strips and/or the absorbent assembly may be provided in a variety of ways. For example, a material or materials from which the backsheet strips and/or the absorbent assembly is/are made may be pleated by any of many known methods. Alternatively, all or a portion of the backsheet strips and/or the absorbent assembly may be made of a formed web material or a formed laminate of web materials like those described in U.S. Pat. No. 5,518,801 issued on 21 May 1996 in the name of Chappell et al. Anexemplary fragment300 of such a formedweb material305 is shown inFIG. 9. This formedweb material305 includes distinct laterally extendingregions310 in which the original material has been altered by embossing or another method of deformation to create a pattern of generally longitudinally oriented alternatingridges312 andvalleys314. The formedweb material305 also includes laterally extendingunaltered regions316 located between the laterally extendingaltered regions310.
• Such a formedweb material305 can be laterally extended beyond its original dimension with the application of relatively less force than that required to extend the same material to the same extent when undeformed. In particular, the application of opposing divergent forces directed generally perpendicular to theridges312 andvalleys314 extends such a formed web material along an axis between the opposing forces and generates a resistive contractive force, primarily in theunaltered regions316. This resistive force is relatively smaller than the resistive force that is generated by the same material in its unaltered form when extended to the same extent, at least up to an extension at which the ridges and valleys in the altered regions flatten and begin to contribute to the resistive force. Thus, such formed web materials exhibit an extensible behavior resembling that of traditional elastic materials in the range of extensibility that is useful in absorbent articles, but may be made of relatively less expensive materials that are not inherently elastic and, thus, their use may provide an advantage in terms of the cost of manufacturing the absorbent articles.
• In addition, different portions of the backsheet strips and/or the absorbent assembly may be formed to have different ranges of extensibility and/or to be extensible to a greater or lesser degree when subjected to a given level of opposing tensile forces, i.e., to be relatively more easily or less easily extensible. Such differential extensibility may be desirable so that, for example, one or both of the waist regions may be laterally extended relatively farther or relatively more easily than the crotch region.
• Description of the Backsheet Strips
• Thediaper20 includes two laterally opposing longitudinally extending backsheet strips designated theleft backsheet strip100aand theright backsheet strip100bas shown inFIG. 1,FIG. 2,FIG. 3,FIG. 4, andFIG. 5. The backsheet strips may be formed of a nonwoven material, for example a synthetic nonwoven such as spunbonded or carded polyethylene, polypropylene, polyester, or rayon.
• Alternatively or in addition, each backsheet strip may include a water-impermeable layer that is formed of a suitable material, for example a film of polyethylene or another polyolefin, a microporous breathable film, a hydrophobic nonwoven, or a film formed of coextruded polyolefin layers. For example, a suitable coextruded film is available from Clopay Plastic Products Co. of Mason, Ohio, U.S.A. under the designation of M18-327. A multi-layer backsheet strip, such as a laminate of a film and a nonwoven, may also be suitable and may be oriented with the nonwoven disposed exteriorly to provide the feel and appearance of a cloth-like outermost layer, with the nonwoven disposed interiorly to separate the film from the skin of the wearer, or with nonwovens disposed both exteriorly and interiorly.
• The front waist region and the back waist region can be fastened together to encircle the waist and the legs of the wearer in many ways. For example, separate fastening devices such as safety pins, separate tapes, a separate tie strap or straps, and/or a separate belt can be used for this purpose. Alternatively or in addition, fastening elements can be incorporated into the disposable absorbent article to enable a user to apply the diaper to the body of the wearer without, or in conjunction with, any separate fastening devices. Many suitable types of such incorporated fastening elements are well-known, including, for example, tapes, adhesives, adhesive tape tabs, ties, buttons, hooks, loops, snap fasteners, other forms of mechanical fasteners, cohesive patches, etc. Some suitable mechanical fasteners may be adapted to engage with a nonwoven, e.g., a nonwoven layer of a laminate backsheet.
• The fastening of the front waist region and the back waist region together may be openable and refastenable to allow for the adjustment of the fit of the diaper on the wearer and for the inspection of the interior of the diaper without fully removing it from the wearer. Alternatively, the fastening may be permanent, i.e., its opening may require the destruction of a portion of the diaper, e.g., the tearing of a portion of the diaper or the breaking of fused side seams.
• Cohesive fastening patches may be formed by the application of a cohesive material onto a substrate. The cohesive material may be applied in any of a variety of patterns, such as a continuous film, discrete dots, stripes, polygons, etc., and/or spaced and interconnected geometric elements describing a grid. Suitable synthetic cohesive products are available from Andover Coated Products, Incorporated, of Salisbury, Mass., U.S.A. and are described in U.S. Pat. No. 6,156,424 issued on 5 Dec. 2000 in the name of Taylor.
• Such cohesive fastening patches may be disposed on the exterior of thediaper20. For example, as shown inFIG. 1,FIG. 2,FIG. 3,FIG. 5,FIG. 10, andFIG. 11,cohesive fastening patches110aand110bmay be disposed on the exterior surfaces of the respective backsheet strips100aand100bin thefront waist region36. In this exemplary embodiment, functionally complementarycohesive fastening patches120aand120bare disposed on the interior surfaces of the respective backsheet strips100aand100bin theback waist region38. When thediaper20 is worn as shown inFIG. 10 andFIG. 11, the cohesive fastening patches on the interior overlap the cohesive fastening patches on the exterior and the cohesion of the overlapped cohesive fastening patches fastens thefront waist region36 and theback waist region38 together at the sides of thediaper20. The configuration shown in these figures is adapted for back-over-front fastening.
• Alternatively, the front cohesive fastening patches may be disposed on the interior of thediaper20 and the back cohesive fastening patches may be disposed on the exterior of thediaper20 in order to adapt the configuration for front-over-back fastening. Alternatively, the cohesive fastening patches may be disposed in a reversible configuration that is adapted to provide the user of the diaper with both options for fastening, i.e., either back-over-front or front-over-back, according to personal preference. For example, cohesive fastening patches that are disposed on both the exterior and the interior of thediaper20 may allow a back cohesive fastening patch to overlap a front cohesive fastening patch or the front cohesive fastening patch to overlap the back cohesive fastening patch.
• When the underlying portion of the diaper is extensible, it is preferable that the cohesive fastening patches be similarly extensible such that the underlying extensible portion of the diaper is not restrained.
• Alternatively, adhesive tape tabs may be attached to thediaper20 and may be used to fasten theback waist region38 and thefront waist region36 together. For example, as shown inFIG. 12 andFIG. 13, laterally opposingadhesive tape tabs114aand114bmay be attached to the respective backsheet strips100aand100bat or adjacent to the side edges137aand137bof thediaper20. Suitable adhesive tapes are available from the 3M Corporation of St. Paul, Minn., U.S.A., under the designation of XMF99121, and from the Avery Dennison Corporation, Specialty Tape Division, Mentor, Ohio, U.S.A., under the designation of F4416.
• Optionally, fastening sheets may also be attached to thediaper20 and used in conjunction with such adhesive tape tabs. For example,fastening sheets116aand116bmay be attached onto theexterior surfaces104aand104bof the respective backsheet strips100aand100bas shown inFIG. 12 andFIG. 13. When a fastening sheet is provided, the adhesive tape tabs may be adhered to the fastening sheet to fasten theback waist region38 and thefront waist region36 together. The fastening sheet serves to distribute the tensile force transmitted by each of the adhesive tape tabs over an area larger than the adhered area of the adhesive tape tab and may, itself, bear a portion of the tensile force and thereby relieve a portion of the force exerted on the underlying portion of the diaper, such as the backsheet strips. Thus, for example, the incorporation of such a fastening sheet may make it possible to use a relatively inexpensive and relatively weak material for the underlying portion of the diaper. When mechanical fasteners are used instead of adhesive tape tabs, a fastening sheet can have a surface and/or elements that engage with the mechanical fastener, e.g., loops with which hooks may engage. When the underlying portion of the diaper is extensible, it is preferable that the fastening sheet be similarly extensible such that the underlying extensible portion of the diaper is not restrained.
• Description of the Absorbent Assembly
• As shown inFIG. 1,FIG. 2,FIG. 3,FIG. 4, andFIG. 5, theabsorbent assembly200 has left and right laterally opposing side flaps247aand247b. The side flaps may be formed by folding portions of the absorbent assembly toward thelongitudinal axis42, to form both the respective side flaps247aand247band the side edges237aand237bof theabsorbent assembly200. Alternatively, the side flaps may be formed by attaching an additional layer or layers to theabsorbent assembly200 at or adjacent to each of the respective side edges237aand237b. In embodiments in which the side flaps are formed by attaching an additional layer or layers to the absorbent assembly, each of the additional layer or layers may be attached at or adjacent to its laterally distal edge.
• In embodiments in which portions of theabsorbent assembly200 are folded laterally inward to form the side flaps247aand247b, theabsorbent assembly200 may simply be folded loosely or may be creased along a portion of each of its side edges237aand237b. For example, it may be desirable to form creases along portions of the side edges237aand237bin thecrotch region37 in order to impart a more finished appearance to thediaper20. Alternatively or in addition to creasing, a portion of each of the folded side flaps247aand247badjacent to the side edges237aand237bmay be attached to theinterior surface202 of theabsorbent assembly200 to achieve a similar result.
• The side flaps may overlap theabsorbent core250, i.e., theproximal edges255aand255bof the side flaps may lie laterally inward of the respectiveleft side edge257aandright side edge257bof theabsorbent core250. Alternatively, the side flaps may not overlap the absorbent core. The side flaps preferably are water vapor-permeable, i.e., breathable, at least in thecrotch region37 where they form side barriers when the diaper is worn, as described in detail below.
• In theexemplary diaper20 shown inFIG. 1, theabsorbent assembly200 extends the full length of the backsheet strips100aand100bbetween the front waist edges136aand136band the back waist edges138aand138b. Such a full length configuration may be desirable in order to minimize the amount of waste material and the difficulty associated with the manufacture of thediaper20, especially when the method used to manufacture thediaper20 requires the introduction of the material or materials for theabsorbent assembly200 in the form of a continuous web or multiple continuous webs. Also, such a full length configuration may be desirable in order to isolate the skin of the wearer from the backsheet strips. Alternatively, theabsorbent assembly200 may be shorter and extend less than the full length of the backsheet strips. Such a shorter configuration may be desirable in order to minimize the total amount of material used and the cost of thediaper20.
• Each of the side flaps247aand247bis attached to theinterior surface202 of theabsorbent assembly200 in attachment zones located at or adjacent to thefront edge236 and theback edge238. For example, in thediaper20 shown inFIG. 1, theleft side flap247ais attached to theinterior surface202 of theabsorbent assembly200 inattachment zones251aand251c, while theright side flap247bis attached to theinterior surface202 inattachment zones251band251d. The attachment zones may have equal areas or may be unequal in area.
• Between the attachment zones, theproximal edges255aand255bof the side flaps247aand247bremain free, i.e., are not attached to theinterior surface202 of theabsorbent assembly200. Also between the attachment zones, each side flap preferably includes a longitudinally extensible flap elastic member that is attached adjacent to the proximal edge of the side flap. For example, in thediaper20 shown inFIG. 1,elastic strands267aand267bare attached adjacent to the respectiveproximal edge255aand255bof the side flaps. The flap elastic member may be enclosed inside folded hems, such as thehems271aand271bshown inFIG. 4. Alternatively, the flap elastic member may be sandwiched between two layers of the absorbent assembly or may be attached on a surface of the absorbent assembly and remain exposed.
• When stretched, the flap elastic members allow the proximal edges of the side flaps to extend to the flat uncontracted length of the absorbent assembly, as shown inFIG. 1. When allowed to relax, the flap elastic members contract to gather the portions of the proximal edges along which the flap elastic members are attached. For example, when theexemplary diaper20 is in a relaxed condition as shown inFIG. 14, theelastic strands267aand267bcontract to gather theproximal edges255aand255bof the side flaps247aand247b. The contractive forces of the elastic strands pull thefront waist region36 and theback waist region38 toward each other and thereby bend theabsorbent assembly200 and theentire diaper20 into a “U” shape in which the interior of the “U” shape is formed by the interior portions of the diaper. Because the proximal edges remain free between the attachment zones, the contractive forces of the elastic strands lift theproximal edges255aand255bof the side flaps247aand247baway from theinterior surface202 of the absorbent assembly and thereby raise the side flaps into position to serve as side barriers. The lateral spacing of the lifted proximal edges is selected to allow the deposit of bodily wastes from the lower torso of the wearer into the space between the raised side flaps. The width of each of the side flaps247aand247bin effect becomes its height when the free portion of its proximal edge is lifted and the side flap is raised. This height preferably is selected to allow the liftedproximal edges255aand255bto fit into the leg creases of the body of the wearer to form seals to help prevent the leakage of deposited bodily waste out of the diaper.
• As shown inFIG. 15,FIG. 16, andFIG. 17, theabsorbent assembly200 includes anabsorbent core250 that serves to absorb and retain liquid bodily waste materials. Theabsorbent core250 has afront edge256, aback edge258, aleft side edge257a, aright side edge257b, aninterior surface252, and anexterior surface254.
• Theabsorbent assembly200 may include an upper covering sheet that is disposed in a face-to-face arrangement with theinterior surface252 of theabsorbent core250 in addition to a lower covering sheet that is disposed in a face-to-face arrangement with theexterior surface254 of theabsorbent core250 and theinterior surfaces102aand102bof the respective backsheet strips100aand100b. If both are present, such an upper covering sheet and lower covering sheet may be attached together to contain theabsorbent core250 between them and thereby form theabsorbent assembly200. For example, in the exemplaryabsorbent assembly200 shown inFIG. 15,FIG. 16, andFIG. 17, anupper covering sheet24 and alower covering sheet25 are attached together at or adjacent to the side edges237aand237bof theabsorbent assembly200 inattachment zones29aand29b.
• The upper covering sheet is water-permeable and allows liquid bodily waste to pass through its thickness to the absorbent core. The upper covering sheet preferably is formed of a soft material that will not irritate the skin of the wearer, for example a synthetic nonwoven such as spunbonded or carded polyethylene, polypropylene, polyester, or rayon.
• The lower covering sheet may include a water-permeable layer of any suitable material, for example the same material as the upper covering sheet. A portion or the whole of either or both of the upper covering sheet and the lower covering sheet may be water vapor-permeable, i.e., breathable.
• Alternatively or in addition, the lower covering sheet may include a water-impermeable layer that is formed of a suitable material, for example a film of polyethylene or another polyolefin, a microporous breathable film, a hydrophobic nonwoven, or a film formed of coextruded layers of polyolefin layers. For example, a suitable coextruded film is available from Clopay Plastic Products Co. of Mason, Ohio, U.S.A. under the designation of M18-327. A multi-layer lower covering sheet, such as a laminate of a film and a nonwoven, may also be suitable and may be oriented with the nonwoven disposed exteriorly to provide the feel and appearance of a cloth-like outermost layer, with the nonwoven disposed interiorly to separate the film from the skin of the wearer, or with nonwovens disposed both exteriorly and interiorly.
• The upper covering sheet and the lower covering sheet may extend to the same width and the same length. Alternatively, one or more of the edges of one of the covering sheets may lie distally relative to the respective edge or edges of the other covering sheet. For example, the upper covering sheet may extend longitudinally only to an extent sufficient to cover the absorbent core and to be attached to the lower covering sheet adjacent to either the front or the back edge of the absorbent core, while the lower covering sheet may extend longitudinally beyond the upper covering sheet toward or to the adjacent waist edges of the backsheet strips. Such a longitudinally extended lower covering sheet may serve to isolate the skin of the wearer from a portion of the backsheet strips as may be desirable, for example, when the diaper is worn under conditions in which contact between the skin and a backsheet film could be uncomfortable. Similarly, the upper covering sheet may extend laterally only to an extent sufficient to cover the absorbent core, or to an extent sufficient to be attached to the lower covering sheet adjacent to either the left or the right side edge of the absorbent core. The lower covering sheet may extend laterally beyond the upper covering sheet. For example, in the exemplaryabsorbent assembly200 shown inFIG. 4, theupper covering sheet24 extends laterally only a relatively small distance beyond the side edges257aand257bof theabsorbent core250 and is attached to thelower covering sheet25 in this area. Thelower covering sheet25 in this exemplary absorbent assembly extends laterally beyond theupper covering sheet24 and is folded to form the side flaps247aand247b.
• The absorbent assembly and the backsheet strips may be attached together over any part or the whole of the length of the absorbent assembly. Preferably, the absorbent assembly is attached on its exterior surface to the backsheet strips in laterally opposing longitudinally extending attachment zones such as theexemplary attachment zones220aand220bshown inFIG. 2,FIG. 3,FIG. 4,FIG. 5,FIG. 13, andFIG. 19. The portions of the backsheet strips that lie outside such an attachment pattern are not restrained by attachment to the absorbent assembly and therefore remain extensible. For example, a relatively narrow longitudinally extending attachment zone such asleft attachment zone220aleaves the majority of the width of theleft backsheet strip100afreely extensible and thereby allows extension of theleft backsheet strip100ain the lateral direction.
• Within the extent of the attachment zones, the absorbent assembly may be attached to the backsheet strips continuously or intermittently. For example, a film of an adhesive may be applied continuously over the entire area of the attachment zones and then used to continuously attach the absorbent assembly to the backsheet strips. As an alternative example, an adhesive may be applied discontinuously at and inside the boundaries of the attachment zones, such as in the form of dots, stripes, beads, spirals, etc., and then used to attach the absorbent assembly to the backsheet strips.
• The absorbent core may be attached to the lower covering sheet over any part or the whole of the area of the absorbent core. Preferably, the absorbent core is attached on its exterior surface to the lower covering sheet in a cruciform attachment pattern, i.e., in an attachment pattern that forms or is arranged in a cross or “+” shape. The cruciform attachment pattern may be contiguous, i.e., all of its portions may be touching or connected throughout the pattern in an unbroken sequence, or may include detached portions and thereby lack contiguity but still be arranged such that the shape of the overall pattern is a cruciform. An exemplary contiguouscruciform attachment pattern210 is shown inFIG. 15,FIG. 16, andFIG. 17. When an adhesive is used for the attachment, less may be necessary in a cruciform attachment pattern than in a more extensive attachment pattern. In addition, the portions of the lower covering sheet that lie outside such a cruciform attachment pattern are not restrained by attachment to the absorbent core and therefore remain extensible. In particular, a relatively narrow longitudinally extendingportion212 of acruciform attachment pattern210 like that shown inFIG. 15 andFIG. 17 leaves the majority of the width of thelower covering sheet25 in thefront waist region36 and in theback waist region38 freely extensible and thereby allows extension of thelower covering sheet25 in the lateral direction in these regions. A relatively wide laterally extendingportion214 of acruciform attachment pattern210 like that shown inFIG. 15 andFIG. 16 prevents the portion of thelower covering sheet25 in thecrotch region37 to which theabsorbent core250 is attached from shifting relative to theabsorbent core250 in that region and thereby contributes to the effectiveness of the raised side flaps. For example, if the lower covering sheet in thecrotch region37 were free to shift laterally, the raised side flaps247aand247bmight distort and fail to maintain contact with the body or become improperly positioned.
• Within the extent of the cruciform attachment pattern, the absorbent core may be attached to the lower covering sheet continuously or intermittently. For example, a film of an adhesive may be applied continuously over the entire area of the cruciform attachment pattern and then used to continuously attach the absorbent core to the lower covering sheet. As an alternative example, an adhesive may be applied discontinuously at and inside the boundaries of the cruciform attachment pattern, such as in the form of dots, stripes, beads, spirals, etc., and then used to attach the absorbent core to the lower covering sheet.
• Theabsorbent core250 includes astorage component272 that serves to absorb and retain liquid bodily waste materials. Suitable known materials for the absorbent core storage component include cellulose fibers in the form of comminuted wood pulp, which is commonly known as “airfelt”, layers or sheets of a natural or synthetic fibrous material or materials, a superabsorbent polymer or polymers, etc. These absorbent materials may be used separately or in combination. Many known absorbent materials may be used in a discrete form, i.e., in the form of fibers, granules, particles, and the like. Such a discrete form of an absorbent material may be immobilized by an adhesive that attaches the discrete pieces together to form a coherent layer or that attaches the discrete pieces to a substrate layer or that attaches the discrete pieces both to each other and to the substrate layer.
• The absorbent core may include an acquisition component in addition to one or more storage components. The absorbent core acquisition component serves to acquire deposited liquid bodily waste material and transfer it to the absorbent core storage component. Any porous absorbent material which will imbibe and partition liquid bodily waste material to the storage component or components may be used to form the acquisition component. Preferred materials for the acquisition component include synthetic fiber materials, open celled polymeric foam materials, fibrous nonwoven materials, cellulosic nonwoven materials, and various combination synthetic/cellulosic nonwoven materials. For example, the acquisition component may be formed of a nonwoven web or webs of synthetic fibers including polyester, polypropylene, and/or polyethylene, natural fibers including cotton and/or cellulose, blends of such fibers, or any equivalent materials or combinations of materials. Examples of such acquisition materials are more fully described in U.S. Pat. No. 4,950,264 issued to Osborn on Aug. 21, 1990. High loft nonwoven acquisition materials suitable for the acquisition component of the present invention can be obtained from Polymer Group, Inc., (PGI), 450 N.E. Blvd, Landisville, N.J. 08326, U.S.A., under the material code designation of 98920.
• Such an absorbentcore acquisition component290 is shown overlying the absorbentcore storage component272 inFIG. 15,FIG. 16, andFIG. 17. Aseparation sheet292 of, e.g., a tissue or a nonwoven material, may be disposed between the absorbentcore storage component272 and the absorbentcore acquisition component290 to help ensure that none of the gel formed by a superabsorbent polymer reaches the skin of the wearer. Thisseparation sheet292 may extend laterally beyond the side edges257aand257bof theabsorbent core250 and theupper covering sheet24 may be attached to theseparation sheet292. In this arrangement, the liquid bodily waste material that is deposited onto theupper covering sheet24 will pass through the thickness of theupper covering sheet24 to be absorbed by the absorbentcore acquisition component290, and some or all of it may then pass through the thickness of theseparation sheet292 and then be absorbed and retained by the absorbentcore storage component272.
• As shown inFIG. 18, in some exemplary embodiments, an absorbentcore storage component272 may include the discrete form of an absorbent material that is immobilized in pockets formed by a layer of a thermoplastic material, such as a hot melt adhesive, that intermittently contacts and adheres to a substrate sheet, while diverging away from the substrate sheet at the pockets. Absorbent core components having such structures and being suitable for the storage of liquid bodily wastes are described in co-pending and commonly assigned U.S. patent applications Ser. Nos. 10/776,839 and 10/776,851, both filed on 11 Feb. 2004 in the name of Ehrnsperger et al. An exemplary absorbentcore storage component272 having such a structure is shown inFIG. 18. In this absorbentcore storage component272,particles270 of a superabsorbent polymer are contained insidepockets280 formed by alayer275 of a thermoplastic material. The absorbent core storage component may include both particles of a superabsorbent polymer and airfelt and both materials may be contained inside the pockets formed by the layer of the thermoplastic material. Alternatively, as shown inFIG. 18, an exemplary absorbent core storage component may contain no airfelt and therefore the component can be made relatively thinner and more flexible for the comfort of the wearer. In addition, the particles of the superabsorbent polymer can be immobilized relatively more easily in the absence of airfelt. As shown inFIG. 18, thelayer275 of the thermoplastic material intermittently contacts and adheres to asubstrate sheet274 at the areas ofattachment282. Between the areas ofattachment282, thelayer275 diverges away from thesubstrate sheet274 to form thepockets280. Thelayer275 may have the form of a sheet of fibers of the thermoplastic material through which the liquid bodily waste may pass to be absorbed by theparticles270 of the superabsorbent polymer.
• InFIG. 18, a separate thermoplasticlayer covering sheet276 is shown overlying thelayer275 of the thermoplastic material. Alternatively, the separate thermoplasticlayer covering sheet276 may be omitted. As another alternative, two absorbent core storage components each like that shown inFIG. 18 except for the omission of the thermoplasticlayer covering sheet276 may be superposed with one absorbent core storage component inverted such that the respective substrate sheets distally oppose each other. In such a combination of absorbent core storage components, either or both of the distally opposing substrate sheets may serve respectively as either or both of an upper covering sheet and a lower covering sheet for the absorbent assembly. Alternatively, the absorbent assembly may include a separate lower covering sheet that is disposed between the absorbent core and the interior surface of the backsheet and/or a separate upper covering sheet that is disposed interiorly of the absorbent core.
• The absorbent assembly may include an additional bottom sheet of a film or other water-impermeable material to enhance the protection against leakage. For example, as shown inFIG. 19, anadditional bottom sheet226 of a film or other water-impermeable material may be attached inside the absorbent assembly between thelower covering sheet25 and theabsorbent core250. Alternatively, the additional bottom sheet may be attached to the absorbent assembly exteriorly of the lower covering sheet. This additional bottom sheet may extend laterally less far than either or both of theleft side edge237aand theright side edge237bof theabsorbent assembly200, as shown inFIG. 19, or may extend laterally to overlap one or both of the side edges of the absorbent assembly.
• When such an additional bottom sheet is attached inside the absorbent assembly between the lower covering sheet and the absorbent core, the additional bottom sheet may be attached to the lower covering sheet in a cruciform attachment pattern similar to that shown inFIG. 15, thus leaving the portions of the lower covering sheet that lie outside the cruciform attachment pattern unrestrained by attachment to the additional bottom sheet and allowing these portions to be extensible. For example, a laterally extendingportion214 of such a cruciform attachment pattern is shown inFIG. 19.
• Alternatively or in addition, the additional bottom sheet in such an embodiment may be attached in such a cruciform attachment pattern to the absorbent core, thus leaving the portions of the additional bottom sheet that lie outside the cruciform attachment pattern unrestrained by attachment to the absorbent core and therefore allowing these portions to be extensible. In such an embodiment, even if the additional bottom sheet is attached to the lower covering sheet in a pattern other than a cruciform, the lower covering sheet is not indirectly restrained by the absorbent core and therefore is allowed to be extensible.
• Description of Shape of Article
• The finished diaper may have a generally rectangular shape, as in theexemplary diaper20 shown inFIG. 1 andFIG. 2. Such a generally rectangular configuration may be desirable in order to minimize the amount of waste material and the difficulty associated with the manufacture of thediaper20. Alternatively, the diaper may haveside edges137aand137bthat are not straight, but instead are curved and/or notched, thereby giving an overall shape in plan view of an hourglass or of an “I” to thediaper20. Such a non-rectangular configuration may be desirable in order to impart a tailored appearance to thediaper20 when it is worn. Such a non-rectangular configuration may also be desirable in order to impart an impression that thediaper20 will fit comfortably between the legs of a wearer.
• A non-rectangular configuration of the diaper may be, formed in any one of several ways. For example, laterally distal portions may be removed from the diaper to make its lateral dimension at and adjacent to thelateral axis44 smaller than its lateral dimension at and adjacent to the front waist edge136 and smaller than its lateral dimension at and adjacent to the back waist edge138, i.e., to make the diaper narrower in thecrotch region37 than at the waist edges. An exemplary form of such a non-rectangular configuration of the diaper is shown inFIG. 20. As shown in this figure, portions of the backsheet strips100aand100bmay be removed to form laterally opposingside notches111aand11b, while leaving the backsheet strips longitudinally continuous. The side notches111 may be disposed entirely laterally distally of the side edges137 of theabsorbent assembly200 as shown inFIG. 20. Each side notch may have a contour formed by longitudinally opposingarcuate portions140 and a generally straight intermediate portion141 connecting the arcuate portions, as shown inFIG. 20.
• Alternatively, a portion of each of the side edges137aand137bmay be folded laterally inward in order to form a non-rectangular configuration of the diaper. For example, as shown inFIG. 21,FIG. 22, andFIG. 23, laterally opposingportions107aand107bof the backsheet strips100aand100bin thecrotch region37 may be folded laterally inward to overlap the respective side flaps247aand247band may be attached to the side flaps, for example, in therespective attachment zones109aand109b. Preferably, each of the folded laterally opposingportions107aand107bextends laterally only a part of the way from therespective side edge237aor237bof theabsorbent assembly200 toward thelongitudinal axis42, thus leaving uncovered respective exposedportions207aand207bof the side flaps, which form side barriers when the diaper is worn, as described above, particularly when the side barriers are breathable.
• As another alternative, the backsheet strips may be made longitudinally discontinuous in order to form a non-rectangular configuration of the diaper. For example, as shown inFIG. 24, the backsheet strips may be separated into a leftfront backsheet strip100a, a leftback backsheet strip100c, a rightfront backsheet strip100b, and a rightback backsheet strip100d, and each of these backsheet strips may extend laterally beyond the side edges237aand237bof theabsorbent assembly200, thereby imparting an “I” shape to thediaper20. The waist edges136 and138 of the discrete backsheet strips100 may be substantially aligned with the respectivefront edge236 andback edge238 of theabsorbent assembly200 as shown inFIG. 24.
• The disclosures of all patents, patent applications and any patents which issue thereon, as well as any corresponding published foreign patent applications, and all publications listed and/or referenced in this description, are hereby incorporated in their entireties herein by reference. It is expressly not admitted that any of the documents or any combination of the documents incorporated herein by reference teaches or discloses the present invention.
• While particular embodiments and/or individual features of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Further, it should be apparent that all combinations of such embodiments and features are possible and can result in preferred executions of the invention. Therefore, the following claims are intended to cover all such changes and modifications that are within the scope of this invention.

Claims (20)

1. A disposable diaper having a front waist region having a front waist edge, a back waist region having a back waist edge, and a crotch region between the waist regions, a lateral axis, and a longitudinal axis, and comprising:

an absorbent assembly having an interior surface, an exterior surface, laterally opposing longitudinally extending side edges, and laterally opposing longitudinally extending side flaps, each side flap having longitudinally opposing ends and a longitudinally extending proximal edge, each side flap being attached adjacent to its ends to the interior surface of the absorbent assembly and having a longitudinally extending elastic gathering member attached adjacent to its proximal edge such that when allowed to relax, the elastic gathering member contracts and lifts the proximal edge away from the interior surface of the absorbent assembly, thereby raising the side flap to form a side barrier; and

two laterally opposing longitudinally extending backsheet strips attached to the exterior surface of the absorbent assembly and extending laterally beyond the side edges of the absorbent assembly, each of the backsheet strips having a laterally distal edge and a laterally outwardly opening side notch formed in its laterally distal edge, the side notch extending longitudinally from the lateral axis toward the waist edges and ending longitudinally proximally of the waist edges, the disposable diaper thereby being laterally narrower in the crotch region than at the waist edges and having an overall shape of an hourglass.

2. The disposable diaper ofclaim 1 wherein the side notch has a contour formed by longitudinally opposing arcuate portions and a generally straight intermediate portion connecting the arcuate portions.

3. The disposable diaper ofclaim 1 wherein the side notch is disposed entirely laterally distally of the side edge of the absorbent assembly.

4. The disposable diaper ofclaim 1 wherein the absorbent assembly comprises a lower covering sheet disposed exteriorly of an absorbent core and forming at least a portion of the exterior surface of the absorbent assembly.

5. The disposable diaper ofclaim 4 wherein the lower covering sheet is attached in a cruciform attachment pattern having a longitudinally extending portion and a laterally extending portion intersecting in the crotch region, the longitudinally extending portion having a smaller lateral extent than the laterally extending portion and the laterally extending portion having a smaller longitudinal extent than the longitudinally extending portion, such that quadrantal portions of the lower covering sheet lying outside the cruciform attachment pattern are unrestrained by attachment to any other element of the absorbent assembly, at least one of the quadrantal portions of the lower covering sheet being laterally extensible.

6. The disposable diaper ofclaim 4 wherein at least a portion of the lower covering sheet between the backsheet strips is laterally extensible.

7. The disposable diaper ofclaim 6 wherein the extensible portion comprises a web material including at least two distinct laterally extending altered regions each containing a pattern of generally longitudinally oriented alternating ridges and valleys in the web material created by a deformation of the web material and also containing an unaltered region located between the altered regions, such that the deformed web material can be laterally extended to a given extent with the application of relatively less force than that required to laterally extend the same web material to the same given extent before the deformation.

8. The disposable diaper ofclaim 4 wherein the lower covering sheet is water-impermeable.

9. The disposable diaper ofclaim 4 wherein laterally opposing portions of the lower covering sheet are folded laterally inward to form the respective side flaps.

10. The disposable diaper ofclaim 4 wherein the absorbent assembly also includes a water-impermeable bottom sheet at least a portion of which is disposed between the lower covering sheet and the absorbent core.

11. The disposable diaper ofclaim 1 wherein at least a portion of at least one of the backsheet strips is laterally extensible.

12. The disposable diaper ofclaim 1 wherein at least a portion of one of the waist regions is laterally extensible to a greater degree than at least a portion of the crotch region.

13. The disposable diaper ofclaim 1 wherein each of the backsheet strips includes a water-impermeable layer.

14. The disposable diaper ofclaim 1 further comprising at least one fastening element adapted for fastening the front waist region and the back waist region together to encircle a leg of a wearer.

15. The disposable diaper ofclaim 14 wherein the fastening element is adapted to be openable and refastenable.

16. The disposable diaper ofclaim 1 further comprising cohesive fastening elements adapted for fastening the front waist region and the back waist region together to encircle a waist and a leg of a wearer, the cohesive fastening elements being disposed on both an interior surface of the disposable diaper and an exterior surface of the disposable diaper and thereby adapted for alternative fastening of the front waist region over the back waist region or the back waist region over the front waist region.

17. The disposable diaper ofclaim 1 wherein each of the backsheet strips has a laterally extending front waist edge and a longitudinally opposing laterally extending back waist edge, at least one of the backsheet strips being laterally extensible at its front waist edge and its back waist edge.

18. The disposable diaper ofclaim 1 wherein each of the backsheet strips is disposed laterally distant from the longitudinal axis.

19. A disposable diaper having a front waist region having a front waist edge, a back waist region having a back waist edge, and a crotch region between the waist regions, a lateral axis, and a longitudinal axis, and comprising:

an absorbent assembly having an interior surface, an exterior surface, laterally opposing longitudinally extending side edges, longitudinally opposing laterally extending front and back waist edges, and laterally opposing longitudinally extending side flaps, each side flap having longitudinally opposing ends and a longitudinally extending proximal edge, each side flap being attached adjacent to its ends to the interior surface of the absorbent assembly and having a longitudinally extending elastic gathering member attached adjacent to its proximal edge such that when allowed to relax, the elastic gathering member contracts and lifts the proximal edge away from the interior surface of the absorbent assembly, thereby raising the side flap to form a side barrier; and

a pair of laterally opposing longitudinally extending front backsheet strips attached to the exterior surface of the absorbent assembly in the front waist region and a pair of laterally opposing longitudinally extending back backsheet strips attached to the exterior surface of the absorbent assembly in the back waist region, each of the backsheet strips extending laterally beyond the side edges of the absorbent assembly, the pair of front backsheet strips being longitudinally spaced apart from the pair of back backsheet strips, the disposable diaper thereby being laterally narrower in the crotch region than at the waist edges and having an overall shape of an “I”.

20. The disposable diaper ofclaim 19 wherein the front backsheet strips have laterally extending front waist edges and the back backsheet strips have laterally extending back waist edges, the front waist edges being substantially aligned with the front edge of the absorbent assembly and the back waist edges being substantially aligned with the back edge of the absorbent assembly.

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