CA2220724A1 - Absorbent article including liquid containment beams and method of manufacture - Google Patents

Abstract

An absorbent article includes a garment shell and first and second liquid containment beams formed of an absorbent material. The liquid containment beams each have an attachment edge bonded to the garment shell so that the containment beam can lie against the garment shell and also pivot about an axis defined by the attachment edge. For comfort during use, the containment beam desirably has a width to thickness ratio of at least about 3:1. In particular embodiments, the absorbent article includes pairs of inner andouter containment beams, with the inner containment beams adaptedto lie against the garment shell and the outer containment beams adapted to lie against the inner containment beams. The liquid containment beams may optionally include leakage barriers to impedelateral movement of liquid. A method of making such absorbent articles is also provided.

Description

ABSORBENT ARTICLE INCLUDING LIQUID CONTAINMENT BEAMS
AND METHOD OF MANUFACTURE

BACKGROUND OF THE INVENTION
s The present invention relates to articles for absorbing body fluids. More particularly, the invention pertains to an absorbent article including one or more containment beams that absorb liquid and impede liquid flow. The invention also pertains to a method of making such absorbent articles.
Disposable absorbent articles such as incontinence undergarments, diapers, feminine products, or the like have commonly included a liquid permeable bodyside liner, a liquid impermeable moisture barrier, and a 9enerally flat absorbent material disposed between the bodyside liner and the moisture barrier. A substantial portion of the 15 absorbent material is routinely positioned in the crotch region of the article where it is likely to directly receive insults of liquid. Rec~-lse the absorbent material tends to swell upon taking in the first insult of liquid, however, the amount of void space in the crotch region available to receive subsequent insults is substantially reduced.

It has also been common for ~lispos~'e absorbent articles to include elastic components, such as leg elastics, waist elastics, and/or elastic fastening devices. The function of these elastic components has been to improve the fit of the absorbent article about the wearer, and thereby enhance the containment of waste materials. Typically, however, the absorbent material is fully bonded or otherwise held immobile between the 2 5 bodyside liner and the moisture barrier. Consequently, the impact of elastic components has been limited to seaiing the periphery of the absorbent article against the body of the wearer, rather than controlling the shape of the article when it is wom.

W O ~G/~0~29 PCTAUS96/08552 Therefore what is lacking and needed in the art is an absorbent article that maintains void space for multiple insults of liquid and that has an absorbent stnucture which pru,,,ùles a product shape that enhances liquid containment.

SUMMARY OF THE INVENTION

In ,~sponse to the ~iscussed deri- ;err --s in the prior art a new absorbent article and method of manufacture have been developed. The absorbent article readily assumes a bucket shape when wom to aid in collecting liquids. Additionally the 10 selection and arrangement of the cor"ponents of the abso,L,enl article provide sufficient void space in an ~cq~ ~isition zone of the article to accept and distribute multiple insults of liquid.

In one embodiment an absorbent article has a garment shell including a moisture 15 barrier and defining an interior surface. First and second liquid containment beams of the absorbent article are formed of an abso.L.enL material and each have longitudinal ends opposile dLId~ l,r"ent and free edges which extend between the longitudinal ends and opposit~ top and bottom surfaces. The ends define therebetween a length dimension the attachment and free edges define therebetween a width dimension and 20 the top and boKom surfaces define therebetween a thickness dimension. A ratio of the width dimension to the thickness ~ "ension is at least about 3:1. The bottom surfaces are adapted to lie against the interior surface and the alld. I""ent edges are bonded to the interior surface so that the liquid containment beams can pivot about an axis defined by the attachment edge.
This embodiment provides absorbent structures in the form of conla;nment beams that are moveable relative to the moisture barrier. In particular each containment beam is free to pivot about an axis defined by its attachment edge in response to movements of the wearer or swelling of the absorbent material. The conlai"",er)l beam for example 30 may swell upon absorbing liquid and thereafter form a physical barrier to inhibit liquid movement within the absorbent article.

In particular e",bod;."ents the absorbent article includes first and second liquid conlai"n,ent beams which are positioned transversely outward of an ~cql~isition zone of 35 the garment shell. For purposes of the present invention the ~cq~isition zone is considered to be the central third of the garment shell in both the longitudinal and transverse . eclions. The abso~be~l artic!e may be configured so that the ~cq~isition zone has a saturated ,etenlion capa.;i4 of less than about 10 per.ient and more desirdbly less than about 5 per e"l, of the total saturated ,elention capacily of the 5 abso,Lent article for improved pelrol,nance. The ~cq~isition zone may include an ~cq~isi~ion/distribution ",aterial posilioned betwccn the containment beams so that the bottom suRace of each conldin",enl beam is arlarted to lie against the ~cq~isition/distribution ",aterial. In this way the abso,benl material of the article is unco~,'ed into distinct containment beams located transversely outward from the 10 longitudinal and transverse center of the article. This facilitates fo",~aLion of a bucket shape in which the containment beams form the sidewalls of the bucket. The ~cq~ ~icition zone forms the center of the bucket and functions to maintain sufficient void space to accG"""odate multiple insults of liquid. Also in particular embodiments, the ratio of the width dimension to the thickness dil"ension is at least about 5:1.
In another en,bod ment an absorbent article has a garment shell including a moisture barrier and derini.-g an interior surface. The absorbent article also includes first and second inner liquid con ~ ~ment beams formed of an absorbent ",alerial and first and second outer liquid cor- ~r"enl beams. Each of the inner and outer liquid 20 co"la;"",ent beams has longitl~ ,al ends opposi~~ dlldcllr"ent and free edges which extend between the longitudinal ends and opposite top and bottom surfaces. The attachment edge of each of the inner and outer liquid containment beams is bonded to the interior surface so that the bottom surface of each of the inner conl&i"ment beams is adapted to lie against the interior surface and the bottom surface of each of the outer 2 5 containment beams is adapted to lie against the top surface of one of the inner con ,r"ent beams. Each of the liquid co" ""ent beams can pivot about an axis defined by its alLach"~ent edge.

This embodiment results in improved comfort for the wearer. The pairs of inner 30 and outer containment beams are distinct structures as opposed to a single integral absorbent structure. Consequently the inner and outer beams can move independently of one another and are less resistant to forces tending to shape the absorbent article.
Further the shingled arrangement of the containment beams provides a gradual increase and then decrease in the thickness of the absorbent article when viewed in the 3 5 transverse direction from the center to each side edge. This is particularly desirable from WO 96/40029 PCT~US96/08552 a cGr"ro.l standpoint when the wearer is in a sitting position. In particular e,~.bo-Ji...e"l:"
each of the con ~ ----ent beams may comprise a plurality of di5c.~le absorbent structures which are themselves in a shingled arrangement to further improve cGr,,ru~l.

Various embodiments further enhance the skin wellness of the wearer due to the incorporation of a breall ~'le moisture barrier. Leakage barriers may desirably be empl~yed to ".in ri~e condensdlion on the exlerior surface of the moisture barrier. In particular embodiments, the leakage barriers include a base portion bonded to the moisture barrier and an exposed portion bonded to the top surfaces of the cor.ldi.,.~ent beams. The absorbent article may also include liquid ~cq-~isition and distribution layers to fe~ lale liquid movement into the cor ~~-~ent beams. In still other embo.li.,.enls, the absorbent article also includes deci~.Anl particles ~isposed aJjacenl the moisture barrier in the acq~isition zone. The desic~rll pdlliCIes function to further .. - ..ke condensation on the exterior surface of the moisture barrier.
In one embodiment, a method of making an absorbent article CGmplises the steps of: providing a garment shell comprisi- ,g a moisture barrier and defining an interior surface; providing a liquid con' ...~enl beam comprising an abso.l,enl material, the liquid conk-;. .r"ent beam having: longitudi )al ends which define therebetween a length 20 dimension; opposite dllachl-,ent and free edges which extend between the longitudinal ends, the dlLdch"~ent and free edges defining therebetween a width dimension; and opposite top and bottom surfaces which define therebetween a thickness dimension, a ratio of the width dimension to the thickness dimension being at least about 3:1; and bonding the dlLacllment edge to the interior surface, the bottom surface being adapted to 25 lie against the interior surface, and the liquid conLail",.ent beam being adapted to pivot about an axis defined by the attachment edge.

In another embodiment, a method of making an absorbent article comprises the steps of: providing a garment shell COIllpliaillg a moisture barrier and defining an interior 30 surface; providing first and second inner liquid con: ~"-ent beams comprising an absorbent material; providing first and second outer liquid co.-l~;n,.,ent beams, each of the inner and outer liquid containment beams having: longitudinal ends; opposileattachment and free edges which extend between the longitl~ ,al ends; and opposite top and bottom surfaces; and bonding the dllacl""ent edge of each of the inner and 35 outer liquid con(a;u~lent beams to the interior surface, the bottom surface Of each Of th~

inner conlb;,~ ent beams being Ada~ d to lie against the interior surface, the bottom surface of each of the outer con Illlenl beams being adapted to lie against the top surface of one of the inner containment beams, and each of the liquid conldill'''ent beams being adapted to pivot about an axis defined by its dllachll lent edge.
Numerous features and advantages of the presenl invention will appear from the following descriplion. In the desc-i,vtion, lererence is made to the accGIllpanying drawings which illustrate prefe"ed embodiments of the invention. Such embodiments do not represent the full scope of the invention. Rererence should lherero~e be made to the 10 claims herein for inlel~lelil l9 the full scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 representatively shows a perspective view of a disposa~le absorbent article 15 accord 19 to the present invention.

Fig. 2 representatively shows a plan view of portions of the disposable absorbent article shown in Fig. 1, taken from the bodyside of the abso,l,ent article in a stretched and laid flat condition and with portions broken away for purposes of illusllalion.
Fig. 3 representatively shows an enlarged section view taken generally from the plane of the line 3-3 in Fig. 2.

Fig. 4 representatively shows an enlarged section view taken generally from the 2 5 plane of the line 4-4 in Fig. 2.

Fig. 5 representatively shows a transverse section view of the absorbent article of Fig. 1 while positioned to simulate the article being wom.

Fig. 6 representatively shows a section view similar to Fig. 5, although illuslldling the absorbent article after liquid has been absorbed.
Fig. 7 representatively shows a plan view of portions of an alle,lldli~/e absorbent article according to the invention, taken from the bodyside of the absorbent article in a stretched and laid flat condition and with portions broken away for purposes of 3 5 illustration.

W O 96/40029 PCT~US96/08552 Fig. 8 representatively shows an enlarged section view taken generally from the plane of the line 8-8 in Fig. 7.

Fig. 9 representatively shows an enla,yed section view similar to Fig. 8, but illustrating an altemative embodiment of the invention.

Fig. 10 representatively shows an enlarged section view similar to Fig. 8, but illusl,dliny another alle" ,alive embo~ " ~,enL of the invention.

Fig. 11 representatively shows a plan view of portions of a further altemative absorbent article according to the invention, taken from the bodyside of the absorbent article in a stretched and laid flat condilion and with portions broken away for purposes of illusl, dlion.
Fig. 12 representatively shows an enlarged section view taken generally from theplane of the line 12-12 in Fig. 1 1.

DEFINITIONS
Within the context of this speciricalion, each temm or phrase below will include the following meaning or meanings:

(a) "Bonded" refers to the joining, adhering, connecting, attaching, or the like, of two elements. Two elements will be consider~d to be bonded together when they are bonded directly to one another or indi~e-,lly to one another, such as when each is directly bonded to intermediate elements.

(b) "Disposable" includes being disposed of after use and not intended to be washed 3 0 and reused.

(c) "Disposed," "disposed on," "-~isposed with," "disposed at," "r~isposed near" and variations thereof are intended to mean that one element can be integral with another element, or that one element can be a separate structure bonded to or 3 5 placed with or placed near another element.

WO 96/40029 PCT/US~6/08552 (d) "Elastic," "el~liu;-~d" and "el~s(icity" mean that prupe,ly of a l"ale,ial by virtue of which it tends to recover its original size and shape after removal of a force causing a der~., . IdLiOn.
(e) "Elaslomeric" refers to a ."dLe,ial or cGr"posile which can be clongdled by at least 25 percent of its relaxed length and which will recover, upon release of the applied force, at least 10 percent of its elongalion. It is generally plefened that the elaslor"eric material or composile be x~-~'e of being elongaled by at least 100 percent, more preferdbly by at least 300 percenl, of its relaxed length and recover, upon release of an applied force, at least 50 percent of its elongalion.

(f) "Exlension," "extend" and "extended" mean the change in length of a ",ale,ial due to sllèlclling, expressed in units of length.
(g) "Fabrics" is used to refer to all of the woven, knitted and nonwoven fibrous webs.

(h) "Flexible" refers to materials which are cGr"r' - ~l and which will readily conr~"" to the general shape and contours of the wearer's body.
(i) "Force" includes a physical influence exerted by one body on another which produces acceleration of bodies that are free to move and deformation of bodies that are not free to move.

25 (j) "Hydrophilic" describes fibers or the surfaces of fibers which are wetted by the ~queo~-s liquids in contact with the fibers. The degree of wetting of the materials can, in turn, be described in terms of the contact angles and the surface tensions of the liquids and mdle, ;als involved. Fql "ment and techniques s~ ~it~le for measuring the vvei'~~''y of particular fiber ~~alel;als or blends of fiber materials 3 0 can be provided by a Cahn SFA-222 Surface Force Analyzer System, or a subslanlially equivalent system. When measured with this system, fibers having contact angles less than 90~ are designated "wettable" or hydrophilic, while fibers having contact angles greater than 90~ are designated "nonwettable" or hydrophobic.

(k) ~ yldl is used to referto various po,lions of a single unitary ele...er,l ratherthan sepa,dle structures bonded to or placed with or placed near one anoU,er.

(I) "Inward" and "outward" refer to posilions relative to the center of an absorbent ga~ enl, and particularly transversely and/or longit~ ' ~ally closer to or away from the longit~ 'inal and transverse center of the absorbent gd-",enl.

(m) "Layer" when used in the singular can have the dual meaning of a single element or a plurality of elements.
(n) "Liquid communi~ ' an" means that liquid such as urine is able to travel from one layer to another.

(o) "Liquid impermeable" when used to describe a layer or lan,i.,al~ means that liquid such as urine will not pass through the layer or laminate under ordinary use conditions in a direction generally perpen'~ r to the plane of the layer or lan ~ale at the point of liquid contact.

(p) "Member" when used in the singular can have the dual meaning of a single 2 o element or a plurality of elements.

(q) "Nonwoven web" means a web of material which is formed without the aid of a textile weaving or knitting process.

25 (r) "Operatively joined" and "operatively connected," with reference to the dlLdch,--ent of an elastic member to another element, means that the elastic member when attached to or connected to the elemenl, or treated with heat or che"U--'s, by stretching, or the like, gives the element elastic properties; and with reference to the attachment of a non-elastic member to another element, means that the 3 0 member and element can be attached in any su ' -' le manner that pemmits or allows them to perform the intended or described function of the joinder. The joining, allacl, ,9, connecting or the like can be either directly, such as joining either member directly to an element, or can be indirectly by means of another member r~isposed between the first member and the first element.

WO 96/40029 PCTAUS96/085~2 (s) "Stretch bonded" refers to an elastic member being bonded to another member while the elastic me---ber is exlended at least about 25 percent of its relaxed length. Desirably, the temm "sl.elch bonded" refers to the Sjtllztjon wherein the elastic member is extended at least about 100 percent, and more desirably at least ~ 5 about 300 percent, of its relaxed length when it is bonded to the other member.

(t) "Stretch bonded laminate" refers to a cGrnpoaile ~alerial having at least two layers in which one layer is a gdU.er ' le layer and the other layer is an elastic layer. The layers are joined together when the elastic layer is in an extended condition so that upon feld~lt;n9 the layers, the gatherable layer is gathered.

(u) "Unadhered" refers to an absence of bonds of sufficient sl,engll, to willlsldnd the forces typically encountered during ordinary wearing of the article.

These terms may be defined with addilional language in the remaining portion of the speciricalion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to Figs. 1-4, an absorbent article formed according to the invention is shown for purposes of illusl,dlion as a clispo~ le under~a""ent 20 for adult incol,li"ence. The invention may also be embodied in other types of absorbent articles, such as other adult care products, reusz 'e absorbent articles, disposa~le diapers, training pants, feminine hygiene products, other personal care or health care garments, 2 5 or the like.

In general, the undergarment 20 includes a gd",~enl shell 45 and a plurality of containment beams 50. Each cou ""ent beam 50 is bonded along an dLlachr"ent edge 62 to an interior surface 46 of the garment shell 45 so that the col ~ment beam is 3 0 pivotable about and axis defined by the allacl " "ent edge in response to lateral compression of the garment shell, extension or conl, ac,lion of elastic members,absorption of liquids, or a cor"bi"alion of these factors. The con" ,r"ent beams 50 are desirably the pl inciple means by which the undergamment 20 retains liquids.

WO 96/40029 PCT~US96/0~552 To ra~ p the underya-,--ent 20 having a bucket shape the con ~ment beams 50 are transversely spaced from the longitudinal center line 22 of the garment shell 45 and located near leg elastic members 48. Further, a relatively flexible material 51 for ~cqu- i--g and/or distributing liquid is desirably located between the cor.lai.~"ent beams 5 50. To p,u",ote comfort the cor ""enl beams 50 desirably have a width to thickness ratio of at least about 3: 1 and more particularly at least about 5: 1. In particular er,.bc lil"ents pairs of containment beams 50 are provided in a sh -_ -d a"~nge,nenl and further, the absolLenl structures 52 within the con ~",ent beams may be in ashi. .gled a" ~nge" ,ent as well. Abs~, l,el-l articles e" ,~ ;ng con .- . .ent beams 50 have 10 been tested and found to have a beneri~ ial impact on reducing le~ ~age cGI"~ar~d to present commercial u"der~d"~ents.

The illustrated undelya--llent 20 defines a longif~ al axis or center line and atransverse axis or center line represented by arrows 22 and 24 in Fig. 2. The 15 ~-"derya""ent 20 has opposite front and back longitudinal end edges 26 and 27, and first and second longitudinal side edges 28 and 29 that extend between the longitudinal end edges. The undergarment 20 includes a first or front waist region 30 a second or back waist region 32, and an intemmediate crotch region 34 posilioned between and i"L~:rconnecting the front and back waist regions. The outer edges of the u"der~a,."enl 20 20 define a periphery 36 in which the longitl ~ J~ 'y extendi, lg side margins are designated 38 and the laterally extending end margins are designated 39. The endedges 26 and 27 and side edges 28 and 29 are shown as generally straight but optionally may be curvilinear and contoured.

The front waist region 30 is contiguous with the front end edge 26 and extends longitudinally inward ther--r u,.~ toward the transverse center line 24 of the undergamlent 20. The back waist region 32 is contiguous with the back end edge 27 and extendslongitudinally inward therefrom toward the transverse center line. The waist regions 30 and 32 col"prise those upper po-lions of underyar",ent 20 which when wom wholly or partially cover or encircle the waist or mid-lower torso of the wearer. The intermediate crotch region 34 comprises that portion of u"de, ya, l "ent 20 which when wom ispositioned between the legs of the wearer and covers the lower torso of the wearer.
Thus the crotch region 34 is the area where insults of urine typically occur in the undergamment or other ~I;sposa~le absorbent article.

W O~C/4C~ PCT~US96/085~2 The illustrated undergarment 20 includes a subsla, ~lially liquid i" ,pe" "eablemoisture barrier 40 and a suL,sldr,lially liquid permeable bodyside liner 44. The moisture barrier 40 and bodyside liner 44 are bonded together such as by ullldso~ bonds thermal bonds adhesives or other sl~ - e means. The peripheries of the moisture 5 barrier 40 and the bodyside liner 44 form the side and end margins 38 and 39 of the underya",~enl 20. Convenlional absG,L.ent products typically employ some fomm ofabs~,be"l structure bet~/0cn the layers functioning as the moisture barrier and the bodyside liner. In the p,~senl underga~menl 20 however the liquid containment beams 50 minimize or eliminate the need for such an absorbent stnucture. Nevertheless in 10 particular embodiments of the present invention it may be desirable to include a tissue layer or a thin layer of ~ellu ose fibers between the moisture barrier 40 and bodyside liner 44 in areas where there are no containment beams 50.

The moisture barrier 40 desirably co",prises a mdlerial that is formed or treated to be liquid impermeable. Altematively the moisture barrier 40 may co" ,prise a liquid permeable material and other s~it~le means (not shown) may be provided to impedeliquid movement away from the crotch region 34 and the liquid conla:.,",ent beams 50.
The moisture barrier 40 may also be vapor permeable such that vapors encounteredduring use of the absorbent garment are able to pass through the ",alelial under ordinary use condilions over either all or part of its surface area.

The moisture barrier 40 may cGmp(ise a single layer of material or a laminate oftwo or more separate layers of ",dlerial. S~it~hle moisture barrier ",dl~,ials include films wovens nonwovens la",indles of films wovens and/or nonwovens or the like. For example the moisture barrier40 may comprise a thin substantially liquid impermeable web or sheet of plastic film such as polyethylene polypropylene polyvinyl chloride or similar material. The moisture barrier material may be transparent or op~que and have an embossed or matte surface. One particular material for the moisture barrier 40 is a polyethylene film that has a nominal thickness of about 0.025 millimeter and a systematic 30 matte err~hossed pattem and that has been corona treated on both sides.

The bodyside liner 44 provides a soft nor, lilaling surface against the skin of the wearer. Acc~n 19l~ a separale layer f~"~clior,;~ ~9 as a bodyside liner may not be needed if the moisture barrier 40 is sufficiently soft and non;"ildling to be positioned against the 35 skin. If used, the bodyside liner 44 may be formed of eithor a liquid porm~eablQ material or, if no layers f-.nclion;"g as absorbent or liquid handling layers are ~:sposed beneath the body liner, a liquid impemmeable material. ~S~ ~it~le bodyside liners 44 may comp(ise a nonwoven web or sheet of wet slrenylll tissue paper, a spunbonded, mel' l~wn or bonded-carded web cG".posed of synthetic polymer Filan,enls or fibers, such as 5 polypropylene, polyethylene, polyesters or the like, or a web of natural polymer fllaments or fibers such as rayon or cotton. In addilion, the bodyside liner 44 is desirably nonelastic and may be treated with a su,ta-,lant to aid in liquid transfer. In a particular e",b_ nent of the invention, the bodyside liner 44 comp,ises a nonwoven, spunbond polypropylene fabric coi"posed of about 2.8 to 3.2 denier fibers formed into a web 10 having a basis weight of about 22 gram per square meter (gsm) and density of about 0.06 gm/cc. The fabric is surface treated with about 0.28 weight percent of a surfactant commercially available from Union Carbide Chemicals and Plastics Company, Inc. of Danbury, Connecticut, U.S.A., under the trade designation Triton X-102.

The portions of the undergarment 20 including the moisture barrier 40, bodyside liner 44 if used, and components therebetween, will be referred to as a ga.,.,enl shell and will be designated reference numeral 45. The garment shell 45, shown in a sl~lched and laid flat condition in Fig. 2, is illustrated as having a ~;tangular periphery 36. Of course, the garment shell 45 may optionally be hourglass-shaped, I-shaped, T-shaped, 20 or irregularly-shaped. The garment shell 45 has an interior surface 46 which is intended to face the wearer when the u"dery~""ent 20 is wom, and an opposile exterior surFace 47. In the illustrated embodiment, the interior surface 46 is generally provided by the bodyside liner 44 and the exterior surface 47 is generally provided by the moisture barrier 40.
Desirably although not necess~rily, the garment shell 45 also includes leg elastic members 48 to draw and hold the side margins 38 of the undergarment 20 against the legs of the wearer and form a seal therewith. The elongated leg elastic members 48 are longitudinally orientated in each side margin 38, extending toward the front and back end 3 0 edges 26 and 27. The leg elastic members 48 are posilioned in the illustrated embodiment between the moisture barrier 40 and the bodyside liner 44. Using ultrasonic bonds, adhesives, thermal bonds, or other s~ ~' 'e means, the leg elastic members 48 are operatively joined in a stretched coodilion to the moisture barrier 40, the bodyside liner 44, or both, in either a straight or a curved shape. Altematively, the leg elastic , CA 02220724 l997-l2-02 members 48 may be operatively joined in a relaxed state to a gathered portion of the moisture barrier 40, the bodyside linef 44, sr both.

The leg elastic members 48 may be formed of a dry-spun ao-'~s~?d mullilila",enl 5 elastomeric thread sold under the tradename LYCRA~ and available from E.l. Du Pont de Nemours and Company. All~ t~ly, the elastic n,e"~be-~ 48 may be formed of other typical elastics utilized in the under,~a----enl-making art, such as a thin ribbon of natural rubber, a stretch bonded laminate material co,..pri~i.,g a prt::,l,etched elastic n.e"' 'own inner layer sandwiched between and bonded to a pair of spunbond polypropylene 10 nonwoven webs, or the like. Fl~sti~ity could also be impa~ led to the absorbent article by extruding a hot melt elastomeric adhesive between the moisture barrier 40 and the liner 44. Other s~ le elastic ~dlhe~ g means are disrlosed in U.S. Patents No. 4,938,754 to Mesek and 4,388,075 to Mesek et al.

In one aspect of the invention, the liquid (etenlion c~acil~ of the underyallllenl 20 is pli".,;pally provided by a number of liquid cGr.lainn,ent beams 50. The undergarment 20 shown in Figs. 1-4 includes four conldinr"ent beams 50, although the particular number of conlai.1ment beams may vary. For ease of rerelence, the con ~",en~ beams 50 will be referred to individually as a first inner containment beam 50A, a second inner 2 0 conlai"",ent beam 50B, a first outer containment beam 50C, and a second outer containment beam 50D. The undergamment 20 also desirably includes ,.,alerial, referred to as an ~cq~ lisition/distribution material 51, that is posilioned bet\,veen the inner containment beams 50A and 50B and adapted to initially take in liquids quickly and/or transport the liquids to the co": ~,--ent beams 50. The ~cq~isition/distribution male,ial 25 51 is adapted by cap;llaly all.ac.liol1, hydrophilic properties, or other s~'~'le means to take in and then release the liquid to the cor,lai,.."ent beams 50.

Each of the illustrated conla;"r.,ent beams 50 is desirably non-elastomeric and col"plised of an absorbent stnucture 52 posilioned within a portion of a support layer 54 30 Figs. 3 and 4. The absorbent structures 52 cor..plise materials adapted to absorb and retain liquid waste. The absorbent stnuctures 52 may comp. ise various absorbentmaterials, such as an air-formed batt of cel' ~la~ic fibers (for example, wood pulp fluff), a coform material composed of a mixture of cellulosic fibers and synthetic polymer fibers, other air-laid composites, or the like. Polymer fibers may be incol ~oraled, for example, in 35 the manner described in U.S. Patent 5,227,107 issued July 13, 1993, to Dickenson et al.

W O 96/40029 PCT~US~6/08'~2 The absG- L,enl structures 52 may also CGlllpl ise compounds such as organic or inoryan ~ high-absorbency materials, which are typically ~r~le of absG~l,i.,g at least about 15 and desirably more than 25 times theirweight in water. ~S~it~ e ~w~"-'le high-absorbency ",alerials are described in U.S. Patents 4,699,823 issued October 13, 1987, 5 to Kellenberger et al. and 5,147,343 issued September 15, 1992, to Kellenberger, which are inco,l,ordled herein by ,~re~nce. High-abso,l,ency ".alerials are available from various cGr"",er~ial vendors, such as Dow Chemical Company, Hoechst Celanese Corporation, and Allied Colloids, Inc. The absorbent structures 52 may also include tissue layers or ~cql~icition or distribution layers to help nl- ~ ~ the integrity of fibrous 10 absorbents or lldnspo,l liquids (not shown). The individual con ",.ent beams 50 may have identical absorbent structures 52 or absorbent structures that differ from one another in density, basis weight, materials, r"dlerial amounts, or other such chara~.lerislics.

Each of the absorbent structures 52 is almost cGIll~!6t Iy enclosed within a portion of the support layer 54. The support layer 54 funclions to contain an absorbent structure 52 while also allowing liquids to pass through to the absorbenl stnucture. The support layer 54 may also function to distribute liquids along and around the absorbent structures 52. The support layer 54 is bonded at spaced locaLions to the bodyside liner 44, thereby 2 0 bonding each of the con' ~" ,ent beams 50 to the interior surface 46 of the gamment shell 45. As best shown in Fig. 3, the support layer 54 may cG",p,ise one integral layer extending across sub~ldl,~;~"y the entire width of the gam~ent shell 45, with dirrelt:nt, transversely spaced pollions w,dpF:.,g each of the absorbent structures 52. The support layer 54 is bonded to the bodyside liner 44 adjacent one of the long edges of each 25 absorbent structure 52. Altematively, a separate support layer 54 may be provided for each absorbent structure 52 (not shown), or no support layer need be used (Fig. 10).

The support layer 54 is desirably fommed of a liquid pemmeable material that is soft and does not irritate the skin of the wearer. The support layer 54 may comprise a woven, 30 knit or nonwoven web. .S~ 'le nonwoven webs include spunbonded, meltblown or bonded-carded webs composed of synthetic polymer filaments or fibers, such as polypropylene, polyethylene, polyesters or the like, or webs of natural polymer filaments or fibers such as rayon or cotton. The support layer 54 may also be treated with a SUI rd~;lanl to aid in liquid transfer to the absorbent structures 52. In particular 35 embodiments, the support layer 54 compriscs a singl~ lay~r construction made from a WO 96/40029 PCTAUS96/~5~52 20.3 gsm (0.6 osy) thermally bonded web with 100 pe~cenl 3 denier polyethylene sheath and polyester core k component staple fibers available from BASF Corporation of Enka North Carolina USA.

Each conldi"" ,ent beam 50 is a generally planar structure having oppocite longitudinal ends 60 which define ther~:betv~ecn a length dimension (Fig. 2). Each of the conla;.""ent beams 50 also has an alldcl,ri,enl edge 62 and an opposi'~ free edge 63 which extend bet~vecn the longitudinal ends 60 (Figs. 2 and 3). A width cJin,e,)sion of each conk.;.""ent beam 50 is defined between the allacl""enl and free edges 62 and 10 63. The width and length dimensions of each cOI~ ""ent beam 50 dictate the size of opposile top and bottom surfaces 64 and 65 of each containment beam 50. The dislance between the top and bottom surfaces 64 and 65 defines a thickness dimension of each con ""ent beam 50.

The con ,r"ent beams 50 are bonded to the ga"nenl shell 45 so that the cGr,ldi"",ent beams are moveable in ~sponse to lateral ~",pressioll of the garment shell extension or conl,d~lion of the leg elastic members 48 abso~lion of liquids or a corn~-.,alion of these factors. One particular method of bonding the conlainn,ent beams 50 to the garment shell 45 is illustrated in detail in the transverse section view of Fig. 3.
2 0 The attachment edge 62 of the first inner CGI 1' ~ 111 ,ent beam 50A is bonded to the interior surface 46. More particularly the support layer 54 is wrapped around the absorbent structure 52 and bonded to the bodyside liner 44 at a bond region 66A. Adhesivesultrasonic bonds thermal bonds mechani- - bonds or other sl ~ le means may used to bond the con ,r"ent beams 50 to the interior surface 46. The localion at which the con )ment beam 50A is attached to the interior surface 46 defines the allachr"ent edge 62. As a result of this method of dllacl""ent and the shape of the containment beam 50A the bottom surface 65 of the first inner containment beam 50A can lay down flat against the acquisition/distribution material 51. Desirably the bottom surface 65 and the free edge 63 are unadhered to the ~cq~isition/ distribution material 51 so that the first inner containment beam 50A is adapted to move relative to the garment shell 45. More precisely the conl~i"r"ent beam 50A is adapted to pivot about an axis defined by its dllacl,l"ent edge 62. While the free edges 63 are illustrated as posilioned closer to the longitudinal center line 22 than the dlld~l""ent edges 62 it should be apparer,l that the orientation of the conla;~""ent beams 50 could be reversed so that the free edges are W O 96/40029 PCT~US96/08552 transversely outward of the allach,--ent edges when positioned flush against the interior surface 46.

The first outer con ----ent beam 50C is attached in a similar ".anner with the 5 attachment edge 62 bonded to the interior surface 46 at a bond region 66C (Fig. 3). The bond region 66C for the first outer containment beam 50C is located between the bond region 66A for the first inner con ~n,ent beam 50A and the first side edge 28.
Attachment of the first outer con ,r"enL beam 50C in this way allows the bottom surface 65 of the first outer containment beam 50C to iay down flat against the top surface 64 of 10 the first inner containment beam 50A. The bottom surface 65 and the free edge 63 of the first outer con ! ""ent beam 50C are desirably unadl,ered to the first innerconlai. ~I"ent beam 50A so that the first outer conta;"ment beam 50C is adapted to move relative to the garment shell 45 and in particular pivot about an axis defined by its ~llacl ,r"ent edge 62.
As suggested in Fig. 3 the second inner and outer con ~ ~".ent beams 50B and 50D are bonded to the interior surface 46 of the garment shell 45 in a similar manner.
The bond regions 66B and 66D where the attachment edges 62 of the second inner and outer conlai. .r"ent beams 50B and 50D are bonded to the bodyside liner 44 lie between 2 0 the longitudinal center line 22 and the second side edge 29. If desired the support layer 54 may be bonded to the bodyside liner 44 and/or moisture barrier 40 transversely outward of bond regions 66C and 66D and between the bond regions 66. The inner containment beams 50A and 50B are considered to lie against the interior surface 46 if they are directly conldcli"g the layer fc,nl- ~g the interior surface such as the bodyside 25 liner 44 or if they are directly conlacling a layer, such as acquisition/distribution layer 51 which is bonded to the layer forming the interior surface.

With reference to Figs. 1 2 and 4 end seals 68 may optionally be attached to theinterior surface 46. The illustrated end seals 68 are bonded over the longitudinal ends 30 60 of the conlai, ." ,ent beams 50 to maintain the bottorn surfaces 65 of the inner containment beams 50A and 50B at the longitudinal ends 60 against the interior surface 46 and to l"aini ~ the bottom surfaces 65 of the outer con ~ ~ment beams 50C and 50D
at the longitudinal ends 60 against the inner containment beams 50A and 50B. The end seals 68 may be formed of any woven or nonwoven mdlerial either liquid permeable or 3S liquid impermeable, and which is desirably soft and not irritating against the skin of the W O 96/40029 PCT~US961~C'~

wearer. As ~iscussed in relation to the embodiment of Fig. 11, the end seals 68 may be liquid impermeable and function to limit lon!~it~ al l"igr~lion of liquid. The end seals 68 may be bonded to the interior surface 46 using adhesives, ulL,dsGn-~ bonds, thermal bonds, mechan;cal bonds, or other s~ le means.
The spacing between the free edges 63 of the inner containment beams 50A and 50B is a function of the width of the containment beams 50A and 50B and lo~lion of their bond regions 66A and 66B. The ~islance between the free edges 63 of the inner conldi"",ent beams 50A and 50B, measured when the ~."deryar",ent 20 is in a stretched 10 and laid flat condition and the con ~ ""ent beams are directed inward against the interior surface 46, is desirably from 0 to about 10 centimeters (cm), and more desirably from about 0 to about 4 cm. Altematively, the di~lance between the free edges 63 may be greater for larger products. Still alle~ali~ely, the free edges 63 of the inner containment beams 50A and 50B may touch or overlap one another (not shown). The containment 15 beams 50 may be attached so that they are parallel, curved or perpendicular to the longitudinal axis 22 of the undergamment 20.

In one aspect of the invention, the shape of the containment beams 50 is select~d to enhance comfort when the u"der~~al",ent 20 is worn. Re~use the conldinn,elll 20 beams 50 are desirably attached to the interior surface 46 at a substantial relative distance from the longitudinal center line 22, it has been recognized that the containment beams 50 should desirably possess a ratio of the width dimension to the thickness dimension of at least about 3:1, so as not to be uncor"forlable, particularly when the wearer is sitting. More desirably, the ratio of the width dimension to the thickness 25 dimension is at least about 5:1, and particularly from about 8:1 to about 10:1, for enhanced comfort. In a particular embodiment, the conlai. ,ment beams 50 have a maximum width dimension of about 2 cm and a maximum II,i~ ness ' "en~ion of about 0.4 cm, resulting in a width to thickness ratio of 5:1. The length of the conlai.,r"ent beams 50 is suitzbly from about 25 to 100 perce"; of the ;ength of the undergarrrlent 20.
30 The width of the containment beams 50 may be conslanl over the length of th containment beams as illustrated, or altematively the width may vary, such as bybecoming wider toward each longitudinal end 60 (not shown).

In another aspect of the invention, the pivotable conla;n" ,ent beams 50 are 35 positioned in a shingled arrangement to further improve co,ll~o~ l. The outer conL~iul"ent W O 96/40029 PCTAJS96/085~2 beams 50C and 50D are adapled to lay against the top surfaces 64 of the inner conla;nn,ent beams 50A and 50B respectively. Further the dlla..l"~,ent edges 62 of the outer coni ""ent beams 50C and 50D are desi~dbly spaced from the dllac;l""ent edges 62 of the inner co,~ ""ent beams 50A and 50B by from 0 to about 100 percent of the 5 width of the outer containment beams 50C and 50D. Mor~3 particularly the allach",ent edges 62 of the outer containment beams 50C and 50D are spaced from the dllacl""ent edges of the inner containment beams 50A and 50B by from about 25 to about 60 percent of the width of the outer con ~ment beams. This shingled arrangement of the conla;nmen~ beams 50 provides a gradual increase and then dec,~ase in thickness of 10 the undergarment 20 in the transverse direction for improved colllrol l.

The ~cql~isition/distribution r"aleri.dl 51 helps to decelerate and diffuse surges of liquid that may be introduced into the crotch region 34 of the garment shell 45. In the illustrated embodiment for e,~d,~ ~le the ~cq~ieition/distribution ~"al~rial 51 is located on 15 and bonded directly to the portion of the support layer 54 that is located between the inner co, ~ment beams which in tum is located on and bonded directly to the interior surface 46 of the garment shell 45. Altematively the ~cql~icition/distribution material 51 may be interposed between the support layer 54 and the bodyside liner 44 or interposed between bodyside liner 44 and moisture barrier 40.
The acquisition/distribution material 51 may comprise any woven or nonwoven web adapted to quickly take in and/or transport liquids. For example the zlcquisition/distribution m~lerial 51 may comprise a nonwoven web such as a spunbonded meltblown or bonded-carded web composed oF synthetic polymer filaments 25 or fibers such as polypropylene polyethylene polyesters or the like or a web of natural polymer filaments or fibers such as rayon or cotton. The ~cq~ ~isition/distribution material may comprise a nonwoven fibrous web composed of a subsld"lially hydrophobic material. In one particular embodiment the ~cql~isition/distribution material comprises a 100 gsm (3.0 osy) web formed of a homogeneous blend of 60 percent 3 denier 30 polyethylene/polypropylene fibers available under the trade desiyllalion ESC-HR5 from Chisso Corporation of Osaka Japan and 40 percent 6 denier polyester fibers available under the trade desig"dlion T-295 from Hoechst Celanese Co~,~oralion of Sommerville New Jersey USA and bonded at 129 degrees Celsius (265 degrees Fahrenheit) for 1.8 seconds. Other sllit~le configurations of the acq~isition/distribution material 51 are 35 described in U.S. Patent 5192606 issued March 9 1993 to D. Proxmire et al.; U.S.

W O 96/40029 PCTrUS96,'~S52 Patent 4,798,603 issued January 17, 1989, to S. Meyer et al.; U.S. Patent 5,364,382 issued November 15, 1994, to M. Latimer et al.; U.S. Patent AFFI. ~icn Ser. No. 757,760 of W. Hanson et al. filed September 11, 1991 (Attomey docket No. 9922); U.S. Patent ~pplkr~tion Ser. No. 206,986 of C. Ellis and D. Bishop, entitled FIBROUS NONWOVEN

LIKE, and filed March 4, 1994 (Attomey docket No. 11,256); and U.S. Patent ApFl c ~S _n Ser. No. 206,069 of C. Ellis and R. Everett, entitled IMPROVED SURGE MANAGEMENT
FIBROUS NONWOVEN WEB FOR PERSONAL CARE ABSORBENT ARTICLES AND
THE LIKE, and filed March 4, 1994 (Attomey docket No. 11,387); the ~icrlosllres of 10 which are hereby ;nCGI ~,oraLed by reference.

The attachment system in the illustrated embodiment includes a pair of strap members 70 and fastening co",ponents to rele~s~hly attach the strap members to the front and back waist regions 30 and 32. The fastening con,ponents include a retainer 72 15 in the form of a button bonded at each end of each strap member 70. The retainers 72 may be rele~s~hly secured in slits 74 formed in the ~a",-en~ shell 45. When the undergarment 20 is posilioned on the wearer, the straps 70 extend between the front and back slits 74 so that the rei ~era 72 may be rele~s~hly secured in the slits. This dllacl""ent system is described in U.S. Patent 4,315,508 to Bolick, which is incoipordled 20 herein by reference. Oplionally, other types of attachment systems, such as tapes, stretchable side panels, self-engaging geometric shaped materials, such as hooks, loops, bulbs, mushrooms, arrowheads, balls on stems, or the like, may be employed.

The strap members 70 (Fig. 1) are each generally rectangular strips of material,25 which is desirably an elastic material c~pr~le of sl,t:lcl )9 to approximately 2.8 to 3 times its relaxed length. The strap members 70 desirably have a length from about 15 to about 41 centimeters (cm.), and a width from about 1 to about 5 cm. For example, each strap member 70 may be 28 cm. Iong and 2.5 cm. wide. The cut ends of the strap members 70 may be bonded by ull,dsonics, adhesives or other su'-~'e means to 30 prevent raveling.

In use, the undergarment 20 is positioned on the body of the wearer and secured in position using the alldchr"ent system. A transverse section view of the undergarment 20 against a contoured surface 76, which represents the legs of a wearer, is shown in Fig. 5 35 to simulate the position of the u"derga(",ent during use. The interaction Of the strap members 70 (Fig. 1) and the leg elastic members 48 cause the side margins 38 to be drawn against the legs of the wearer. It should also be noted that lateral cor,.pr~ssion of the undergarment 20 ~e~ecn the legs and exlension of the leg elastic members 48 may cause the con ,r"ent beams 50 to pivot away from the interior surface 46 of the 5 ga""enl shell 45.

The garment shell 45 defines an ~cc~ sition zone 78 (Figs. 1 5 and 6) which is the region of the garment shell that is likely to directly receive insults of liquid. For purposes of the present invention, the ~cq~isition zone 78 shall be consider~d to consist of the 10 central one-third of the garment shell 45 in the longitudinal ~ ~ lion 22 and the central one-third of the garment shell in the transverse direction 24 measured while the garment shell is in a stretched and laid flat position. In the illustrated embodiment the ~cql~isition/distribution material 51 covers the interior surface 46 of the garment shell 45 in the ~cq~ ~isition zone 78.
In one aspect of the invention the undergarment 20 tends to form a bucket shape (Fig.5) with the con .r..ent beams 50 located along the sidewalls of the bucket and forming an inwardly-extending lip of the bucket. The acquisition/distribution material 51 in the ~cq~isition zone 78 forms the bottom of the bucket. The conlain.),ent beams 50 are desirably located in the transverse direction 24 between the ~cql~isition zone 78 and the first and second side edges 28 and 29. More particulal~y the attachment edges 62 of the conla;n" ,ent beams 50 are desirably bonded to the interior surface 46 at a transverse location outward of the acq~ ~isition zone 78 and at or inward of the position of the leg elastic members 48. Specifically the allachr"ent edges 62 of the contai"i"ent beams 50 are desirably located between 0 to about 5 cm from the leg elastic members 48, and more desirably between 0 to about 2.5 cm for improved performance. By positioning the conlai""-ent beams 50 in the outer transverse thirds of the garment shell 45 the containment beams tend to form part of the sidewalls of the bucket shape.Additionally the ~cq~isition zone 78 is desirably more flexible than the outer transverse thirds of the garment shell 45. As a result of the greater flexibility of the acq~ ~isition zone 30 78 and the use of separate independent containment beams 50 the garment shell 45 tends to form inflection points 79 between the inner conlai.lr"ent beams 50A and 50B.
The cG"la;"r"ent beams 50 are located transversely outward of the inflection points 79 forming the sidewalls of the bucket shape and the ~cq~ ~isition zone 78 is located between the inflection points forming the bottom of the bucket shape.

W O 96/40029 PCT~US96/08552 In another aspect of the invention the acq~isition zone 78 (Figs. 5 and 6) of the underyd""ent 20 provides void space to rapidly take in multiple insults of liquid. Fig. 6 shows a transverse section view of the undergarment 20 similar to Fig. 5 but illusl,ali"g the position of the containment beams 50 after the underga""ehl has abso,bed an insult 5 of liquid. Insults of liquid tend to be quickly taken up by the accl~lisition/distribution " ,alel ial 51 and sl Ihseq-lently desorbed by the absorbent structures 52 of the containment beams 50. Consequentiy the containment beams 50 may tend to swell asillustrated in Fig. 6. The ~cq~isition zone 78 and the region between the containment beams 50 continue to provide void space to accept addilional insults of liquid. Further 10 the partially or fully swollen containment beams 50 tend to function at least in part as physical barriers to lateral liquid flow.
The undergarment 20 may be constructed so that the acq~isition zone 78 has a saturated liquid retention capacily that is from 0 to about 50 percent such as from 0 to about 30 percent of the total saturated liquid ~t:tenlion capacily of the undergarment.
15 More desirably to rllC~;.lldill the void volume of the ~cq~isition zone 78, the undergarment 20 is constnucted so that the ~cq~ ~isition zone comprises less than about 10 percent and even more desirably less than about 5 percent of the total saturated ,t:tenlion capacity of the undergarment. By way of illusl,alion an ~cq~isition zone 78 in an undergarment 20 adapted for use by moderately incontinent adults may have a saturated reler)lion2 0 capacity of from about 30 to about 50 grams.

The saturated ,t:lenlion capacity of the ~cq~ ~isition zone 78 and the remainingportions of the unde,ya""ent can be determined by cutting the acq~isition zone from the undergarment measuring the saturated r~tenlion capacity of both and co",pari"g the 2 5 value obtained for just the ~cq~ ~isition zone to the total value of the ~cq~ ~isition zone and the remaining portions. It should be understood that the free edges 63 of the containment beams 50 may be positioned over the acq~isition zone 78 but do not form part of the ~cq~isition zone if the alldcl,-"ent edges 62 are bonded to the interior surface 46 transversely outward from the ~cq~isition zone. The saturated retention capacity of 3 o the acquisition zone 78 and the remaining portions of the underya" "enl can be determined according to the Saturated Retention Capacity Test as set forth in the TEST
PROCEDURES section below. In particular embodiments the undergarment 20 is constructed so that the containment beams 50 comprise from about 50 to 100 percent of the saturated liquid retention capacity of the undergarment and more particularly from 3 5 about 90 to 100 percent for improved pe~ ru~ ance.

An allal"ali./e underga~ ent 80 accor.li"g to the present invention is illustrated in Figs. 7 and 8, where components similar to those previously described have been given the same lererence numeral. The undergarment 80 includes first and second inner liquid con' I,llen~ beams 50A and 50B and first and second outer liquid conl~;,lment beams 50C and 50D, all bonded to the interior surface 46 of a garment shell 45. An ~cqllisition/distribution malerial 51 is positioned between the inner liquid containment beams 50A and 50B, and longitudinal end seals 68 may be provided to tack down the longitudinal ends 60 of the conlain",ent beams 50.
The garment shell 45 includes a bodyside liner 44 and a moisture barrier 40, thelatter of which may co")p,ise a liquid impermeable inner layer 82 and a soft outer layer 83. In one particular embo.limenl, the inner layer 82 cor"pnses a cast or blown film formed of polypropylene, polyethylene or the like, and the outer layer 83 comprises a spunbond web formed of polypropylene and polyethylene medium-crimped bicomponentfibers in a 50/50 side-by-side configuration. The inner and outer layers 82 and 83 may be bonded together such as by a pattemed appli~alion of adhesive, by thermal bonds, or othersllit~le means.

The garment shell 45 of the undergarment 80 also includes optional supplemental absorbent assemblies 84 rlisposed between the bodyside liner 44 and the moisturebarrier 40. The supplemental absorbent assemblies 84 are desirably positioned between the acql ~isition zone 78 and the front and back end edges 26 and 27 of the garment shell 45 to improve fit, comfort and liquid absorbency in the front and back waist regions 30 25 and 32. Alternatively, the supplemental absorbent asselll~liec 84 may also be disposed in the crotch region 34 of the undergarment 80. The supplernental absorbent assemblies 84 may be formed of layers of tissue, wood pulp fluff, or other absorbent materials such as those described above in relation to the absorbent structures 52 of the containment beams 50. Elastic members such as leg elastic members 48 are also desirably bonded 30 between the bodyside liner 44 and the moisture barrier 40. To enhance the ability of the elastic members 48 to shape the undergarment 20, the supplemental absorbent assemblies 84 are desirably not attached directly to, and therefore uncoupled from, the cOnlail Iment beams 50.

W O 96/40029 PCT~US96/08552 As best illustrated in Fig. 8 each of the conlain~ent beams 50 includes a plurality of individual absorbent structures 52 within a support layer 54. The individual absorbent structures 52 within each con ~ ent beam 50 are in a shingled arrangement wherein the individual abso,ber,l stnuctures are positioned on top of one anoll,er but also offset 5 from one another in the transverse ~ ecliol1 24. This shingled arrangement of the absorbent structures 52 within each of the conlai,)",ent beams 50 as well as theshingled ar,dnger"ent of the outer conlain~ent beams 50C and 50D over the inner con .,..ent beams 50A and 50B provides a gradual incr~ase and then decrease in thickness of the u..derga",)ent 80 in the transverse di ~.lion 24 for improved col"roll.
10 The illustrated containment beams 50 include three individual abso,Lenl structures 52 per containment beam although the particular number may vary. Altematively a single absorbent structure 52 having a gradually increasing and then decreasing thickness profile in the transverse direction 24 may be used (not shown).

The undergarment 80 also includes leakage barriers 86 that are bonded to the topsurface 64 of the outer conldi.""ent beams 50C and 50D to inhibit lateral " ig,dlion of liquids and present a dry surface against the legs of the wearer. The leakage barriers 86 may be formed of any soft liquid impermeable material. For example the leakage barriers may comprise a two layer adhesive composite consisting of a liquid impermeable 20 layer 87 and a soft nonwoven layer 88. In one embodiment the leakage barriers 86 comprise an adhesive laminate of a 17 gsm (0.5 osy) 2.5 denier spunbond polypropylene and a 0.01 millimeter polyolefin based film. As shown in Fig. 8 portions of the leakage barriers 86 may extend transversely outward of the outer con ~ment beams 50C and50D and be bonded to the interior surface 46 inward of the side edges 28 and 29. The 2 5 leakage barriers 86 may be bonded to the containment beams 50 and the interior surface 46 using adhesives ull,dsonic bonds thermal bonds mechanical bonds or other suitable means.

A further alternative constnuction of an undergarment 90 accordi.,g to the present 30 invention is partially illustrated in Fig. 9. The undergarment 90 includes a bodyside liner 44 bonded to a moisture barrier 40 with leg elastic members 48 positioned therebetween. The moisture barrier 40 desirably cor"~lises a vapor permeable andsubstantially liquid impermeable material. Alternatively the moisture barrier 40 may col "prise several regions with at least one region being vapor permeable and 35 substantially liquid impermeable.

W O 96/40029 PCT~US96/08552 The moisture barrier 40 suitably comprises, for example, a material having a water vapor transmission rate (W~TR) value of at least about 100 grams per square meter per 24 hours (gmlmZ124 hr). More particularly, the moisture barrier 40 cor"p~ises a ",ale,ial 5 having a W~TR value of at least about 2,000 gmlm2124 hr, and more desirably having a WVTR of at least about 3,000 gmlm2124 hr, for improved pe,rur",ance. One sllt--'e procedure for measuring the WVTR value of a materi31 is set forth in the TEST
PROCEDURES section below. The moisture barrier 40 may cor"p,ise, for example, any micro-porous, uredlll-~le~ ale~ial which pemmits gases, such as water vapor, to escape 10 while subslanlially preventing liquid e~ Id~t~s from passing Iher~ll ,ruugh. S~ lit~le breathable materials include a microporous polymer film or a nonwoven fabric which has been coated or otherwise treated to impart a desired level of liquid impemmeability, or the like. For example, a s~iP~le n,i: upo~uus film is available under the trade designation PMP-1 from Mitsui Toatsu Chemicals, Inc., a co~pany having offices in Tokyo, Japan;
15 or a polyolefin film available under the trade designation XK:0-8044 from 3M Company of Minneapolis, Minnesota, USA.

The undergarment 90 also includes desicc~nt particles 92 positioned between the moisture barrier 40 and the bodyside liner 44. The desicc~-lt particles 92 minimize the 20 fommation of condensation which may tend to form on the exterior surface 47 of the breathable moisture barrier 40. The desic-~nt particles 92 may be wrapped in anenvelope 94 cor"prisi"g, for example, a nonwoven web such as a tissue or spunbond material. Altematively or in addition thereto, the desiccant particles 92 may be held in place with adhesives or other co",ponents (not shown). The undergarment 90 also 2 5 includes an acquisition/distribution material 51, and the desicc~n~ particles may altematively be positioned between the bodyside liner 44 ~nd the ~cq~isition/distribution material. Desiccant particles 92 sl~ le for use in the undergamment 90 include calcium chloride, calcium oxide, superdbso, L,ent materials, silica gel, or the like. In one embodiment, an envelope 94 is formed by two layers measuring 10.16 by 40.64 30 centimeters which are bonded together and 1.0 gram of calcium oxide (CaO) is evenly distributed between the layers. Each layer co~prises a 13.5 gsm (0.4 O5y) point bonded web formed of 50 percent polyethylene sheath / 50 percent polypropylene core 2.6denier bicomponent fibers.

=

WO 96/40029 PCTrUS96/08552 To further ",ini",i e the ,l~olel~lial rGIIIIaljOn of condensdlion on the outer surface of the breathable moisture barrier 40 the undergarment 90 is provided with leakage bdl I ier~
86 at least partially positioned betvecn the con:, ~",enl beams 50 and the moisture barrier. The leakage bd"ier~ 86 will thus tend to isolate the absG,bent structures 52 of 5 the COli ""ent beams 50 from the moisture barrier 40 as well as illhibiling lateral migralion of liquids and providing a dry surface against the legs of the wearer. The Icakage barriers 86 desirably have a base portion 96 bonded to the moisture barrier 40 and an PYposed portion 97 bonded to the top surface of at least the outer conk..."oent beams 50C and 50D. As illustrated the exrosed portion 97 extends inward a sufficient 10 distance so that it is posiliGned against and bonded to at least a portion of the top surface 64 of each inner conl~;"ment beam 50A and 50B as well.

The undergarment 90 may optionally be provided with a distribution layer 98 to promote liquid movement from the ~cql~i~ition/distribution ",alerial 51 to the conLd;.,rl,ent 1 5 beams 50. The distribution layer 98 is desirably bonded onto the base portion 96 of the leakage barriers 86 using adhesives ull,ason.c bonds thermal bonds mecl,anical bonds or other suitable means. The distribution layer 98 is positioned on top of the base portion 96 so that it is in liquid commu, - cn with the con - ~ment beams 50. The dllachment edges 62 of the con ""ent beams 50 are then bonded to the distribution layer 98.2 0 Most desirably the inner portion of the distribution layer 98 overlaps the outer portion of the acquisition/ distribution material 51 so that the distribution layer and acquisition/distribution ",alerial are in liquid communic- cn.

The distribution layer 98 may comprise any material that directs liquid flow in one or 2 5 more directions in the plane defined by the length and width of the distribution layer. The distribution layer 98 is suitably a nonwoven web made of cel I'DS C fibers or thermoplastic fibers such as polyethylene polypropylene polyester or the like and can be formed as a bonded carded web a meltblown web a spunbonded web or blends thereof. In one specific embodiment the distribution layer 98 comprises a 75 gsm (2.2 osy) 30 hydroentangled pulp sheet made with soft wood pulp available from Kimberly-Clark Corporation of Neenah Wisconsin U.S.A. under the trade designation Longlac 19. The pulp sheet includes 1 weight percent surfactant available from Witco Chemical Corporation O,yal1ics Division of Melrose Illinois USA under the trade desiy"alion AROSURF~ PA727. The distribution layer 98 may altematively comprise slivers sliver-35 like materials sulfonated pulps or the like.

O 96/40029 PCT~US96/08552 Another altemative construction of an undergarrnent 100 acco.d;"g to the presentinvention is partially illustrated in Fig. 10. The undergarment 100 includes a bodyside liner 44 bonded to a moisture barrier 40, with co.. la;.. ent beams 50, acquisition/distribution material 51, and leg elastic members 48 all ~isposed between the bodyside liner and the moisture barrier. The bodyside liner 44 is desirably bonded directly to the moisture barrier 40 and ~cq~ ~isition/distribution ~"alerial 51, but need not be bonded directly to the con' ~ment beams 50 to allow for movement of the con' ~n~ent beams.
The containment beams 50 of the undergarment 100 consist of absorbent structures 52 and do not include support layers 54 as illustrated in the previous embodiments. The absorbent structures 52 desirably have sufficient integrity to be bonded along their dllacl-ment edges 62 to the moisture barrier 40 and to remain an integral structure even after absoi L .. ~g liquid. For example, the absorbent structures may comprise a coform malerial formed of a matrix of thermoplestic polymer fibers and individualized wood pulp fibers ~ I;sposed throughout the matrix. S~ ~it~'e coform materials are ~lisrlosed in U.S. Patent 4,100,324 issued July 11,1978, to Anderson et al.;
U.S. Patent 4,604,313 issued August 5, 1986, to McFarland et al.; and U.S. Patent 5,350,624 issued September 27, 1994, to Georger et al.; the dis-~osl-res of which are incorporated herein by reference. Particularly where the con' ..oent beams 50 are bonded to the moisture barrier 40 in the manner illustrated in Fig. 10, it will be apparent that a portion of the absorbent structure 52 remote from the free edge 63 may optionally not be bonded directly to the moisture barrier 40, provided the containment beam has a portion functioning as an allacl ~-nenl edge and the free edge is moveable relative to the garment shell 45. Because the bodyside liner 44 is positioned over the con' ~ ent beams 50, the liner is not considered to form part of the garment shell 45 in this embodiment.

A still further alte.. dli./e undergarment 110 according to the present invention is illustrated in Figs. 11 and 12. The undergamment 110 includes a garment shell 45 with a bodyside liner 44 bonded to a moisture barrier 40, and leg elastic members 48 positioned therebetween. First and second containment beams 50A and 50B are bonded to the interior surface 46 of the garment shell 45, with an acquisition/distribution assel"bly 112 positioned between the cGn~dir~l"ent beams. The ~cqu;sition/distribuUon assembly 112 WO 96/40029 PCT~US9G/08552 co" ,p, ises an inner ~cq~ ~isition/distribution " ,alerial 51 and an outer ~cquicition/distribution liner 114.

The ~cq~icitionldistribution liner 114 includes a facing layer 116 that is folded and 5 bonded to itself to fomm a pair of peaks 118 that are sepa,~led by a channel 120 (Fig.
12). The facing layer 116 may be formed of a wide variety of liquid pe,.,.--ble ...alel;als, including but not limited to woven l..ale.ials such as cloth, knit r~alenals, pe""--' 'e films, foams and fibrous nonwoven Illalt:l;als. In one particular embodiment, the facing layer 116 co"~p,ises a single layer constnuction made from a 20.3 ~sm (0.6 osy) themmally 10 bonded carded web material utilizing 100 percent 3 denier t-~n,ponent staple fibers from BASF CG,~oralion. The hbers are 38millimeters (mm) (1.5 in) in length and cor. .p. ise a polyethylene sheath surrounding a polyester core. One s~ ' ' e acq~isition/distribution ~--dL~:lial 51 ~I~p~ises a single layer structure, such as a 20.3 gsm (0.6 osy) through-air bol~ded carded web made coll F'et-~'y from 1.8 denier polyethylene 15 sheath/polypropylene core ~ --ponent fibers having a length of 38 mm (1.5 in) and available from BASF Corporation.

A filler 122 formed of a ~~ nl, liquid permeable ~--dlelial is folded upon itself and disposed within the peaks 118. In one embodiment, the filler 122 ~r"prises strips of a 20 85 gsm (2.5 osy) bonded carded web including 60 weight percent 3 denier polyethylene sheath/polyester core bicomponent staple fibers available from BASF Corporation under the trade desig"dlion CS-2 and 40 weight percent 6 denier rayon fibers available from Courtaulds Fibers, Inc. of Axis, Alabama, USA. Facing layers 116 of the foregoing type are ~isclosed in U.S. Patent Appl.- ~ic n Ser. No. 169,449 by M. Weber et al., filed 25 December 17, 1993, and titled "Liquid Absorbent Material For Personal Care Absorbent Articles And The Like" (Attomey Docket No. 10,880), the r~iscl~sl lre of which is inco".ordled herein by reference.

The co"ldi"n,ent beams 50A and 50B of the undergarment 110 each co",p,ise a 30 pair of absorbent structures 52 wrapped in a common support layer 54. The absorbent structures 52 are somewhat offset in the transverse direction 24 so as to be in a shingled relationship.
.

The undergarment 110 also includes end seals 68 to maintain the longitudinal ends 35 6Q of the containment beams 50 against the interior surface 46 Of the gamment shell 45 W O 96/40029 PCT~US96/08552 and to provide a physical barrier to longitudinal movement of liquid. In this particular e"~bodiment, the end seals 68 are formed of an elastomeric r"atenal and have integral first and second po,lions 124 and 126 adjace"l the opposite longitudinal edges of the end seal. The first po, lions 124 are posilioned closer to the transverse center line 24 of 5 the underya" "ent 110 and are desirably unadhered to the interior surface 46. In cor,l,dal, the second pollions 126 are posilioned further from the transverse center line 24 and are directly bonded to the interior surface 46. In this way, the first po,lions 124 tend to stand up from the interior surface 46 and form lon3it~ al liquid bd"ie~a when the end seals 68 are allowed to cor,l,a-,l. The end seals 68 desirably do not su6slanlially 10 gather the ga",~enl shell 45 in the transverse direction 24.

Containment beams 50 as described in relation to the ror~goi.)g embodiments may also be el"r'3yed on other disp~--'le absorbent products. Exd,rF'es of such products, for instance, are ~fisclosed in U.S. Patent ArFI.- ~ on Ser. No. 08/168,615 by T. Roessler 15 et al., filed December 16, 1993, and titled "Dynamic Fitting Diaper" (Attomey Docket No.
10,961); U.S. Patent Appli~ on Ser. No. 08t168,615 by E. D. Johnson et al., filed August 12, 1994, and titled "Diaper With improved Lateral Clo"galion Cl,d,dclerislics"
(Attomey Docket No. 11,629); and U.S. Patent4,940,464 issued July 10, 1990, to P. Van Gompel et al.
The f~ ;.lg EXAMPLES are provided to give a more de: 'ad ~"~deraldnding of the invention. The particular amounts, proportions, col"posilions and parameters are meant to be exemplary, and are not intended to specifically limit the scope of the invention.

A number of test undergarments representing one el"bo " "ent of the present invention were constructed. These test undergarments included a moisture barrierformed of a polyethylene film and measuring 68.6 by 22.1 cm. Leg elastic members30 were operatively joined to the moisture barrier along the two side margins in the crotch region of the garment.

The test undergarments included two conldi,l"lent beams each measuring 54.6 cm long, 3.2 cm wide, and 1 cm thick. Each containment beam included three identical 35 absorbent structures stnGked on top of one another~ Th~ absorbent structures were WO 96/40029 PCT~US~G/~S52 formed of a mixture of 50 weight percent wood pulp fluff and 50 weight percent superdbsorbent particles. The abso.benl structures were sub~lanlidlly fully wrapped in a single support layer formed of a 20 gsm thermally bonded carded web of polyethylene sheath and polyester core ~ .ponent fibers from BASF CG-~Grdlion which were treated with 1.5 weight per~ent su,rd- lanl available from Union Carbide Cl~e~n -- - and rlaslics Company Inc. underthe trade desiy..alion Triton X-102. The support layerwas bonded to the moisture barrier so that each conl i---ent beam was pivotable about an axis defined by its dlachmenl edge. The conldi."..enl beams were curved slightly so that the free edges of the containment beams were spaced apart by about 4 cm at their longitudinal center and spaced apart by about 7 cm at their longitudinal ends. The contai"r,~ent beams were generally centered in the longitudinal direction of theundergarment and spaced from the leg elastic members by about 2.5 cm. The two containment beams had a combined saturated rete- llion capacity of about 450 grams.

An ~cq~ lisition/distribution asse~--bly was posilioned betr/ccn the containmentbeams and bonded to the support layer. The ~sq~isition/distribution assembly col..prised an ~cquisition/distribution ~"alerial r~isrosed on and bonded to the support layer between the conlainr"ent beams. The ~cq~-isition/distribution material measured 54.6 cm long and 10.2 cm wide and cGr"~J,ised a 50 gsm spunbond web formed of side-by-side polypropylene/polyethylene bicomponent fibers.

The ~cql~isition/distribution assembly also included an ~cquisition/ distribution liner similar to that illustrated in Figs. 11 and 12. The ~cql~isition/distribution liner measured 25.4 by 10.2 cm and was bonded onto the acquisition/distribution material. The ~cql ~isition/ distribution liner included a facing layer that was folded and bonded to itself to form a pair of peaks that were separaled by a channel. A filler was positioned in the peaks and the facing layer was bonded to a backing layer.

The facing and backing layers each coi"prised of a single layer construction made from a 20.3 gsm thermally bonded carded web material utilizing 100 percent 3 denier bico",ponent staple fibers from BASF Corporation. The fibers which were 38 mm inlength and comprised a polyethylene sheath surrounding a polyester core were treated with 1.5 weight percent su,racla,1l available from Union Carbide Che".;- ~ ~ and rlaslics Company Inc. under the trade desiy- .alion Triton X-102. The filler comprised strips of an 85 gsm bonded carded web including 60 weight percent 3 denier polyethylene sheath/

WO 96/40029 PCT~US~6/0~

polyester core ti~n,ponent staple fibers available from BASF Co",G,dlion under the trade designaliol- CS-2 and 40 weight percent 6 denier rayon fibers availabie from Courtaulds Fibers Inc. of Axis Alabama USA.

The ~cq~icitionldistribution asser,bly also included two relatively narrow strips of ~cq~isition/distribution l"de,ial ~I;;posed between the ~oq~-isition/distrjbution liner and the 54.6 by 10.2 cm layer of acql~i~ition/ distribution n,alenal. The strips, which were st~ ked on top of one another measured 25.4 by 2.5 cm and 25.4 by 5.1 cm. Thê strips were formed of the same ",de,ial as the 54.6 by 10.2 cm layer of ~cq~ ition/ distribution 10 1 1 ,alerial.

The ~cquisition zone of the underya~"enl defined as the central one third of thegdl'''enl shell in the longitudinal 1 ec lion and the central one third of the gamment shell in the transverse direction cGr"prised less than 5 percent of the total saturated retenlion 15 capacily of the undergarment.

The test u,1derya""ents also induded a single peak structure posilioned between each containment beam and each set of the leg elastic ",embet:,. Each peak structure was identical in construction and r"alerials as the peaks formed in the 20 ~cqnisition/distribution liner. The peak sb~uctures outward of the conlai.""ent beams however were 35.6 cm long whereas the peaks of the ~cql~isition/distribution liner were only 25.4 cm long.

End seals formed of a liquid impermeable material and measuring 2.5 by 15.2 cm 25 were positioned over the longitudinal ends of the cGnlai. ,",enl beams and bonded to the support layer. Additionally a bodyside liner material was bonded to the moisture barrier in locations not covered by the support layer. The bodyside liner compnsed a 20 gsm spunbond web formed of polypropylene fibers.

3 0 The fastening system for the test undergarments included two strap members that were formed of an elastic malelial purchased from Shelby Fl~stics of Shelby North Carolina USA. The strap members had a length of about 26 cm and a width of about2.5 cm. Buttons were attached near each end of each strap member and ,~i.,roreedbuttonholes were formed on each underyar",ent.

WO 96/40029 PCTAUS~61'~9eS2 The underydl",ents of Test Example 1 were ev~'uated relative to cGr"pardlive undergarments cG"~spor, ' ~g to undergarments of the type sold in about August of 1994 by Kimberly-Clark Co, ~ordlion under the tradename Deper,d~3). The co" ,pa~dlive5 undergarments included a moisture barrier, leg elastic members, and a fastening system similar to those used in the test underga~" ,ents.

A generally planar absG,L e"l assembly was ~isposed on the moisture barrier. Theabsorbent asse",bly measured 59.4 by 14.5 cm and was fommed of cellulose fluff, 10 sprayed polypropylene rila" ,enl~, and superabsorbent pa, li-,las. The absG, benl assembly was wrapped in tissue and the tissue was attached to the moisture barrier using a construction adhesive. A bodyside liner was disposed on the absorbent assembly and bonded to the moisture barrier outward of the abso,L.ent assembly. The bodyside liner comprised a 20 gsm spunbond polypropylene web that was treated with 15 1.5 weight percent sulraclant available from Union Carbide Chemicals and rlaslics Company, Inc. under the trade designation Triton X-102. The compa, dli~/e undergarments had a saturated retention capacity of about 450 grams.

For purposes of analyzing the performance of the undergarments of Test Example 20 1, a forced failure test was conducted. The test used 36 pa,li~,i,vanl~ including 18 men and 18 women. The participants were each fitted with an apparatus that included a flexible tube having an exit end positioned in the crotch region. Each participant was asked to wear either the Test Example 1 undergarment or the Cor"pa,dlive Example 1 undergarment, selected randomly, under an appropriately sized pair of underwear. After 2 5 the participant wore the undergarment for 30 minutes, the participant was seated and the u,)derya~l"ent was then loaded through the tube with three insults of 24 milliliters (ml) of 0.9 percent saline solution spaced 60 seconds apart. Two minutes later, the participant rose to a standing position while a gush of 72 ml of saline solution was infused into the tube. The participant remained standing for two minutes after which time the pa,li~ .anl 30 was seated. Additional insults of 24 ml of saline solution were loaded through the tube at 60 second intervals until leakage occurred. This procedure was repeated so that each participant tested each of the Test Example 1 undergarments and each of the Comparative Example 1 undergarments twice.

WO 96/40029 PCT/US96/08S~;2 The undergarments of Test Example 1 were found to have absorbed an average of about 186.85 grams of liquid at the point of leakage compal~d to an average of about 146.49 grams of liquid at the point of leakage for the undergarments of Compardli~/e Example 1. Table 1 below shows the average loading value at the point of leakage for 5 each palli..;panl for the two Test Example 1 undergarments and the two Colllpdldli~/e Example 1 underg~""enls. The average and standard deviation values were r~'~~ t~d from the individual observed values rather than the mean values shown in the table.

WO 96/40029 PCT~US96/08552 Pa, lic;, allt COMPARATIVE EXAMPLE 1 TEST EXAMPLE 1 Mean Std Dev Mean Std Dev 107.50 20.51 195.50 20.51 2 164.50 3.54 175.50 9.19 3 127.00 18.38 127.50 43.13 4 117.50 28.99 117.00 28.28 94.00 2.83 95.00 1.41 6 118.00 4.24 184.00 36.77 7 134.50 48.79 202.00 16.97 8 191.50 30.41 181.50 17.68 9 177.00 14.14 179.50 50.20 121.50 0.71 178.50 16.26 11 134.00 49.50 215.50 31.82 12 177.00 15.56 227.50 14.85 13 131.50 16.26 156.50 14.85 14 109.50 14.85 253.50 45.96 103.50 17.68 249.00 46.67 16 224.00 8.49 250.50 13.44 17 212.00 28.28 195.00 70.71 2 5 18 181.50 21.92 279.00 57.98 19 131.00 21.21 226.50 14.85 143.50 4.95 217.00 39.60 21 141.50 64.35 283.00 35.36 22 168.00 1.41 262.00 36.77 23 164.00 25.46 167.50 4.95 24 203.00 14.14 266.00 36.77 112.00 33.94 121.50 34.65 26 119.00 103.24 191.50 106.77 27 176.50 20.51 164.00 25.46 28 215.50 4.95 137.50 68.59 29 165.50 4.95 238.50 3.54 190.00 7.07 192.00 5.66 31 117.50 41.72 136.00 73.54 32 121.50 28.99 176.50 113.84 33 120.00 2.83 167.50 2.12 34 137.50 53.03 129.00 41.01 117.50 31.82 97.00 0.00 36 104.00 18.38 91.00 4 24 Average 146.49 42.02 186.85 61.07 A number of test undergarments having the general configuration of the undergarment 110 shown in Figs. 11-12 were also constnucted. The undergar",enls of Test Example 2 included a bodyside liner end seals leg elastic members and a 5 fastening system similar to those used in the unde,ya""ents of Test E-xample 1. The undergd""ents of Test Example 2 did not include the single peak stnuctures bet~ecn the conla;.,ment beams and leg elastic members as were used in the u"dergd""ents of Test Example 1.

The undergarments of Test Example 2 included a moisture barrier co",prised of anadhesive la"l ~ale of an inner layer and an outer layer. The inner layer co",prised a liquid and vapor impemmeable polyethylene film and the outer layer co",prised a point bonded spunbond nonwoven formed of polypropylene and polyethylene medium-crimpedk.. D.nponent fibers in a 50/50 side-by-side configuration. The moisture barrier measured 15 68.6 by 22.1 cm.

The undergarments of Test Example 2 included two cor- ~ ,i"ent beams each measuring 44.5 cm long 3.2 cm wide and 1 cm thick. Each conlc.i"",ent beam included two identical absorbent stnuctures slightly offset in the transverse ~ t:clion so as to be in 20 a shingled configuration (see Fig. 12). The absorbent structures were formed of a mixture of 80 weight percent wood pulp fluff and 20 weight percent superabsorbent particles. The absorbent structures were substantially fully wrapped in a single support layer formed of a 20 gsm thermally bonded carded web of polyethylene sheath and polyester core bicomponent fibers from BASF Cor~ordlion which were treated with 25 1.5 weight percent su,raclanl available from Union Carbide Chemicals and Plastics Company Inc. under the trade designalion Triton X-102. The support layer was bonded to the moisture barrier so that each containment beam was pivotable about an axis defined by its attachment edge. The con ~ment beams were curved slightly so that the distance between the free edges varied between about 5 and about 7 cm. The 30 containment beams were skewed toward the front end edge of the undergarment and spaced from the leg elastic members by about 2.5 cm. The Lwo containment beams had a combined saturated retention capacity of about 260 grams.

An acquisition/distribution assembly measuring 25.4 by 10.2 cm was positioned 3 5 between the containment beams and bonded to the support layer. The - 34 - ~

O 96/40029 PCT~US96/08552 acquisition/distribution assembly cGn,prised an acq~icition/distribution liner similar to that employed in the undergarments of Test Example 1. The acquisition/distribution liner measured 25.4 by 10.2 cm and was positioned between the containment beams and bonded to the support layer. The acquisitionldistribution liner included a facing layer that was folded and bonded to itself to form a pair of peaks that were separated by a channel.
A filler was positioned in the peaks, and the facing layer was bonded to a backing layer.
The " ldlerials used to form the facing and backing layers and the filler were the same as in the undergarments of Test Example 1.

The acquisition/distribution assembly also included two relatively narrow strips of ~cql~isition/distribution ",ale~ial disposed between the ~cquisition/distribution liner and the support layer. The strips, which were stacked on top of one anolher, measured 25.4 by 2.5 cm and 25.4 by 5.1 cm. The strips comprised a 50 gsm spunbond web formed of side-by-side polypropylene/polyethylene bicomponent fibers.
The acquisition zone of the undergarment, defined as the central one third of the garment shell in the longitudinal direction and the central one third of the garment shell in the transverse direction, co",prised less than 5 percent of the total saturated retention capacity of the undergarment.

Comparative undergarments similar to those of Comparative Example 1 were also provided for purposes of evaluation. The undergarments of Co",pa,dli./e Example 2, however, were modified as follows. First, the tissue did not complEtely wrap theabsorbent assembly so that a middle portion of one surface of the absorbent assembly was directly bonded to the moisture barrier using a construction adhesive. Second, the bodyside liner was directly bonded to the tissue using a construction adhesive. And third, the undergarments of Comparative Example 2 included an acquisition/distribution materi31 mezsurir,g 25.4 5y 10.2 cm. Th~: acquisiiionidistribution materiai, which comprised a 75 gsm bonded carded web formed of polyethylene fibers, was bonded to the side of the bodyside liner facing the moisture barrier using a construction adhesive.

The performance of the undergarments of Test Example 2 and the undergarments of Comparative Example 2 was colllpared in a forced failure evaluation. This forced failure evaluation utilized 36 participants including 18 men and 18 women. The pa,li..ipanl~

-were each fitted with an appardl.ls that included a flexible tube having an exit end positioned in the crotch region. Each participant was asked to wear either the Test Example 2 undergarment or the Comparative Example 2 undergarment, selected Idndo",ly, under an appr~,p,iately sized pair of underwear. The undergd,l"enl was then loaded through the tube with an initial load of 100 ml of 0.9 percent saline solution while the participant was standing. After 30 minutes of wear time and in increments of 5 minutes thereafter, sl Ihsequent loads of 24 ml of saline solution were loaded through the tube while the participant was sitting, until leakage occurred. This procedure was repeated so that each pdl li~,;par)L tested each of the Test Example 2 undergarments and each of the Comparative Example 2 undergarments twice.

The undergarments of Test Example 2 were found to have absorbed an average of about 390.50 grams of liquid at the point of leakage compared to an average of about 151.88 grams of liquid at the point of leakage for the undergarments of Comparativ Example 2. Table 2 below shows the average loading value at the point of leakage for each participant of the two Test Example 2 undergarments and the two ComparativeExample 2 undergarments. The average and standard deviation values were ~l~ul~ted from the individual observed values rather than the mean values shown in the table.
Participants 13, 17, 22, 30 and 35 only tested one of the Test Example 2 undergarments.

WO 96/40029 PCT~US96~'a'5'2 Pa,li-,i"a,~l COMPARATIVE EXAMPLE 2 TEST EXAMPLE 2 Mean Std Dev Mean Std Dev 127.00 2.83 442.50 61.52 2 107.50 16.26 308.50 60.10 3 155.00 63.64 505.50 34.65 4 172.00 4.24 394.00 16.97 149.00 72.12 315.00 91.92 6 168.50 2.12 395.00 65.05 7 164.50 0.71 480.00 121.62 8 180.67 32.33 354.00 308.30 9 241.00 69.30 356.50 111.02 174.00 12.73 398.50 152.03 11 180.00 46.67 476.00 39.60 12 137.00 16.97 410.00 5.66 13 131.00 24.04 342.00 14 96.00 1.41 313.00 32.53 104.50 2.12 335.00 69.30 16 99.50 2.12 215.50 26.16 17 126.50 34.65 233.00 18 150.50 2.12 269.00 60.81 19 170.00 2.83 339.00 134.35 202.00 15.56 635.00 31.11 21 152.50 48.79 525.50 89.80 22 168.00 70.71 507.00 23 152.00 63.64 446.00 24.04 24 209.50 14.85 474.00 116.00 16.97 361.00 39.60 26 107.00 18.38 323.00 60.81 27 110.00 14.14 278.50 19.09 28 117.50 28.99 357.00 14.14 29 126.00 39.60 296.50 85.56 164.00 31.11 505.00 31 182.50 10.61 487.50 31.82 32 196.50 43.13 474.50 55.86 4 o 33 167.00 1.41 497.50 21.92 34 154.00 0.00 411.00 28.28 163.00 32.53 292.00 36 131.50 14.85 310.00 8 49 4 5 Average 151.88 41.03 390.50 110.29 Several pa,li~ anls noted that the undergarments of Test Example 2 were less bulky than the u~derya""ents of Con,pa,dli.~e Example 2. Additionally several pa~ ipal1ls noted that the undergarments of Test Example 2 did not feel ~ "co"~rortable in either the dry or wet state. It is hypothesized that the underya""e, ll:, of Test Example 2 had a greater average loading value at the point of leakage compared to the undergarments of Test Example 1 because the co" ! ""ent beams of Test Example 2 provided greater open spaces for liquid to reside.

TEST PROCEDURES
Saturated Retention caPacitv The saturated rete"lion eapacil~r of a material is measured as follows. The Illalelial to be tested having a moisture content of less than about 7 weight percent is weighed and submerged in an excess quantity of room temperature (about 23 degrees Celsius) synthetic urine. The malerial to be tested is allowed to remain submerged for 20minutes. After 20 minutes the "~alerial is removed from the urine and placed on a TeflonO coated fiberglass screen having 0.25 inch openings (commercially available from Taconic Plaslics Inc. Petersburg New York) which in tum is placed on a vacuum box and covered with a flexible nubber dam material. A vacuum of 3.5 kilopa~c~ls (0.5 pounds per square inch) is drawn in the vacuum box for a period of 5 minutes. The material is weighed. The amount of fluid retained by l:he ~"alarial being tested is determined by suL,t,acli,1g the dry weight of the material from the wet weight of the material (after applicalion of the vacuum) and is reported as the saturated retention capacity in grams of fluid retained. For relative comparisons this value can be divided by the weight of the material to give the saturated retention capacity in grams of fluid retained per gram of tested material.

The synthetic urine composition referenced herein comprises 0.31 grams monobasiccalcium phosphate monohydrate (CaH4(PO4)2H2O) 0.68 grams monobasic polassium phosphate (KH2PO4) 0.48 grams magnesium sulphate heptahydrate (MgS04 7H20) 1.33 grams potassium s~ ~, hale (K2SO4) 1.24 grams tribasic sodium phosphate dodecahydrate (Na3PO4 12H20) 4.4 grams sodium chloride (NaCI) 3.16 grams potassium chloride (KCI) 8.56 grams of urea (CO(NH2)2) 0.1 grams Pluronic 10R8 surfactant (a non-ionic surfactant commercially available from BASF-Wyandotte Corporation) and 1 gram methyl paraben and 1 gram Germall 115 preservative W O 96/40029 PCTAJS96,'L'''?

(commercially available from Santell Chemical Company, Chicago, Ill.) per liter using distilled water as the solvent. The cor"ponents are added to 900 milliliters of distilled water in the order given and each dissolved before the next co",ponent is added. The solution is finally diluted to one liter.

If mdlerial, such as high-abso,l,ency material or fiber is drawn through the fiberglass screen while on the vacuum box, a screen having smaller openings should be used.Alternatively, a piece of tea bag material can be placed between the material and the screen and the final value adjusted for the fluid retained by the tea bag ",aLerial.

10 Suit~hle tea bag material is a heat se~'~'~le tea bag material grade 542, commercially available from Kimberly-Clark Co"~ ordlion. The amount of fluid absorbed by the tea bag material is determined by performing the saturated retention capacily test on an empty tea bag. Testing high-absorbency ",alerials or fibers alone can be accor"F' shed using a sealed pouch of tea bag ",alerial.
Water vaPor T,dns,-,ission Rate A suitable techr,~ e for determining the WVTR (water vapor ll dnsmission rate) value of a material is ASTM Standard E96-80. For the purposes of the present invention, circular sar"Fles measuring 3 inches in diameter are cut from the test material and a 20 control material which is a piece of CELGUARD~) 2500 film from Hoechst Celanese Cor,~ordlion of Sommerville, New Jersey, USA. CELGUARD~) 2500 is a 0.0025 cm thick microporous polypropylene film.
Five samples are prepared for each material. The test dish is a No. 60-1 Vapometer pan distributed by Thwing-Albert Instrument Company, Phil~delr~hia, Pennsylvania, U.S.A.
25 One hundred milliliters of water are poured into each Vapometer pan, and each of the samples of the test material and control material are placed across the open tops of the individual pans. Do not apply stopcock grease unless sample conlami.,ation can be avoided. Screw-on flanges are tightened to form a seal along the edges of the pans, leaving the ~ssoci~ted test " ,alerial or control material ~xrosed to the ambient 30 atmosphere over a 6.5 cm diameter circle having an exposed area of about 33.17 square centimeters. The pans are placed in a forced air oven set at 32~C (100~F) for 1 hour to equilibrate. The oven is a constant temperature oven with extemal air circulating through it to prevent water vapor accumulation inside. A suitable forced air oven is, for example, a Blue M Power-O-Matic 60 oven distributed by Blue M Electric Co. of Blue Island, lllinois, 35 U.S.A. Upon co",ple(io,1 of the equilibration, the pans are removed from the oven, weighed and immediately retumed to the oven. After 24 hours, the pans are removed from the oven and weighed again. The preliminary test WVTR value is ~'c~l~ated as follows:
Test WVTR = (grams weight loss over 24 hours) x 315.5 (glm2124 hours) 5 The relative humidity within the oven is not specifically co, ~ lle d Under predetermined set concJilions of 32~C (100~F) and ambient relative humidity, the WVTR for CELGUARD~) 2500 has been determined to be 5000 gmlm2124 hours.
Accordingly, the CELGUARD~ 2500 is run as a control sample with each test, and the 10 pr~' "il,ary test values are co, lt:~led to the set conditions using the following equation:
WVTR = (Test WVTR/control W~TR) x 5000 gmlm2/24 hr.

The foregoing detailed descli~lion has been for the purpose of illu:~l,alion. Thus, a number of modiri~lions and changes may be made without departing from the spirit and 15 scope of the present invention. For instance, alternative or optional features described as part of one embodiment can be used to yield another embodiment. Additionally, two named components could represent portions of the same structure. Therefore, the invention should not be limited by the specific embodiments described, but only by the claims.

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Claims (41)

We claim:

1. An absorbent article, comprising:
a garment shell comprising a moisture barrier and defining an interior surface; and first and second liquid containment beams, each liquid containment beam comprising an absorbent material and having:
longitudinal ends which define therebetween a length dimension;
opposite attachment and free edges which extend between the longitudinal ends, the attachment and free edges defining therebetween a width dimension; andopposite top and bottom surfaces which define therebetween a thickness dimension, a ratio of the width dimension to the thickness dimension being at least about 3:1;
wherein each attachment edge is bonded to the interior surface, each bottom surface is adapted to lie against the interior surface, and each liquid containment beam is adapted to pivot about an axis defined by its attachment edge.

2. An absorbent article comprising:
a garment shell comprising a moisture barrier and defining an interior surface;
first and second inner liquid containment beams comprising an absorbent material;
and first and second outer liquid containment beams, each of the inner and outer liquid containment beams having:
longitudinal ends;
opposite attachment and free edges which extend between the longitudinal ends; and opposite top and bottom surfaces;
wherein the attachment edge of each of the inner and outer liquid containment beams is bonded to the interior surface, the bottom surface of each of the innercontainment beams is adapted to lie against the interior surface, the bottom surface of each of the outer containment beams is adapted to lie against the top surface of one of the inner containment beams, and each of the liquid containment beams is adapted to pivot about an axis defined by its attachment edge.

3. The absorbent article of claim 1 or 2, wherein the liquid containment beams are adapted to pivot upon swelling of the absorbent material.

4. The absorbent article of claim 1 or 2, wherein the containment beams each comprise a plurality of individual absorbent structures in a shingled arrangement within a support layer.

5. The absorbent article of claim 1, wherein the free edges of the liquid containment beams are separated by a distance of from 0 to about 10 centimeters when the absorbent article is in a stretched and laid flat condition.

6. The absorbent article of claim 1, wherein the garment shell has a first waist region, a second waist region, and a crotch region positioned between and interconnecting the first and second waist regions, the crotch region including an acquisition zone having lateral boundaries inboard of the attachment edges of the first and second liquid containment beams.

7. The absorbent article of claim 6, wherein the acquisition zone has a saturated retention capacity that is less than about 10 percent of the total saturated retention capacity of the absorbent article.

8. The absorbent article of claim 6, wherein the acquisition zone has a saturated retention capacity that is less than about 5 percent of the total saturated retention capacity of the absorbent article.

9. The absorbent article of claim 6, wherein the acquisition zone comprises an acquisition/distribution material, and each bottom surface is adapted to lie directly against the acquisition/distribution material.

10. The absorbent article of claim 2, wherein the garment shell has a first waist region, a second waist region, and a crotch region positioned between and interconnecting the first and second waist regions, and the crotch region includes an acquisition zone having lateral boundaries inboard of the attachment edges of the first and second inner liquid containment beams.

11. The absorbent article of claim 1 or 2, wherein the garment shell further comprises elastic members transversely outward from the liquid containment beams, the elastic members being oriented generally parallel to the longitudinal axis.

12. The absorbent article of claim 1 or 2, wherein the garment shell has longitudinal and transverse axes, and the length dimension of each of the liquid containment beams is oriented generally parallel to the longitudinal axis.

13. The absorbent article of claim 1 or 2, wherein the garment shell has longitudinal and transverse axes, and in the transverse direction the garment shell forms first and second outer thirds and a central third between the first and second outer thirds, the containment beams being bonded to the interior surface in the first and second outer thirds.

14. The absorbent article of claim 1 or 2, wherein the liquid containment beams comprise from about 90 to 100 percent of the total saturated retention capacity of the absorbent article.

15. The absorbent article of claim 2, wherein the attachment and free edges define therebetween a width dimension, the top and bottom surfaces define therebetween a thickness dimension, and a ratio of the width dimension to the thickness dimension is at least about 5:1.

16. The absorbent article of claim 1 or 2, wherein each of the containment beamscomprises and absorbent structure disposed within a liquid permeable support layer.

17. The absorbent article of claim 16 wherein the support layer comprises one integral layer that is bonded at spaced locations to the interior surface a plurality of containment beams being wrapped within the support layer.

18. The absorbent article of claim 2, further comprising end seal means for maintaining the longitudinal ends of the inner containment beams against the interior surface and the longitudinal ends of the outer containment beams against the inner containment beams.

19. The absorbent article of claim 18, wherein the end seal means comprises an elastic and liquid impermeable material bonded to the interior surface.

20. The absorbent article of claim 1 or 2, further comprising an acquisition/distribution material disposed on the interior surface between the containment beams.

21. The absorbent article of claim 20, wherein the absorbent article forms a bucket shape, the containment beams forming sidewalls of the bucket and the acquisition/distribution material forming a floor of the bucket.

22. The absorbent article of claim 1 or 2, further comprising a bodyside liner bonded to the moisture barrier and a supplemental absorbent assembly disposed between the bodyside liner and the moisture barrier.

23. The absorbent article of claim 1 or 2, wherein the containment beams are disposed between a bodyside liner and the moisture barrier.

24. The absorbent article of claim 1, further comprising leakage barriers, the leakage barriers bonded to the top surfaces of the liquid containment beams and comprising a liquid impermeable material.

25. The absorbent article of claim 2, further comprising leakage barriers, the leakage barriers, the leakage barriers bonded to the top surfaces of the outer liquid containment beams and comprising a liquid impermeable material.

26. The absorbent article of claim 24 or 25, wherein the leakage barriers extendtransversely outward of the containment beams and are bonded to the interior surface between the containment beams and the side edges.

27. The absorbent article of claim 24 or 25, wherein the leakage barriers have a base portion bonded to the moisture barrier and an exposed portion bonded to the top surface of the containment beams.

28. An absorbent article, comprising:
a garment shell comprising a moisture barrier formed of a vapor permeable and substantially liquid impermeable material, the garment shell defining an interior surface, opposite end edges, opposite side edges extending between the end edges, a first waist region, a second waist region, and a crotch region positioned between and interconnecting the first and second waist regions, the crotch region including an acquisition zone spaced inward from the side edges; and first and second liquid containment beams, each liquid containment beam comprising an absorbent material and having:
longitudinal ends;
opposite attachment and free edges which extend between the longitudinal ends; and opposite top and bottom surfaces;
an acquisition/distribution material disposed on the moisture barrier between the containment beams; and desiccant particles disposed between the moisture barrier and the acquisition/distribution material;
wherein each attachment edge is bonded to the interior surface between the acquisition zone one of the side edges, each bottom surface is adapted to lie against the interior surface, and each liquid containment beam is adapted to pivot about an axis defined by its attachment edge.

29. The absorbent article of claim 28, wherein the moisture barrier includes a portion having a water vapor transmission rate (WVTR) value of at least about 2000 grams per square meter per 24 hours.

30. The absorbent article of claim 28, wherein the moisture barrier includes a portion having a water vapor transmission rate (WVTR) value of at least about 3000 grams per square meter per 24 hours.

31. The absorbent article of claim 28, wherein the desiccant particles are wrapped in a vapor permeable envelope.

32. The absorbent article of claim 28, further comprising leakage barriers bonded to the moisture barrier and positioned at least partially between the containment beams and the moisture barrier.

33. An absorbent article having longitudinal and transverse axes, longitudinal end edges, and first and second side edges extending between the longitudinal end edges, the absorbent article comprising:
a moisture barrier;
first and second liquid containment beams comprising an absorbent material, the liquid containment beams having:
longitudinal ends;
opposite attachment and free edges which extend between the longitudinal ends; and opposite top and bottom surfaces; and an acquisition/distribution assembly disposed on the moisture barrier between the first and second liquid containment beams;
wherein the attachment edge of each of the liquid containment beams is bonded tothe moisture barrier, the bottom surface of each of the containment beams is adapted to lie against the acquisition/distribution assembly, and each of the liquid containment beams is adapted to pivot about an axis defined by its attachment edge.

34. The absorbent article of claim 33, wherein the acquisition/distribution assembly comprises an acquisition/distribution liner and an acquisition/
distribution material positioned between the acquisition/distribution liner and the moisture barrier, the acquisition/distribution liner comprising a liquid permeable facing layer that is folded and bonded to itself to form a pair of peaks separated by a channel, and a resilient filler material folded upon itself and disposed within the peaks.

35. The absorbent article of claim 33, further comprising elastic members bonded to the moisture barrier and disposed between the first and second sides edges and each of the first and second liquid containment beams, the attachment edges of the liquid containment beams located from 0 to about 2.5 centimeters of the elastic members.

36. A method of making an absorbent article, comprising the steps of:
providing a garment shell comprising a moisture barrier and defining an interiorsurface;
providing a liquid containment beam comprising an absorbent material, the liquidcontainment beam having:
longitudinal ends which define therebetween a length dimension;
opposite attachment and free edges which extend between the longitudinal ends, the attachment and free edges defining therebetween a width dimension; andopposite top and bottom surfaces which define therebetween a thickness dimension, a ratio of the width dimension to the thickness dimension being at least about 3:1; and bonding the attachment edge to the interior surface, the bottom surface being adapted to lie against the interior surface, and the liquid containment beam being adapted to pivot about an axis defined by the attachment edge.

37. A method of making an absorbent article, comprising the steps of:
providing a garment shell comprising a moisture barrier and defining an interiorsurface;
providing first and second inner liquid containment beams comprising an absorbent material;
providing first and second outer liquid containment beams, each of the inner andouter liquid containment beams having:
longitudinal ends;
opposite attachment and free edges which extend between the longitudinal ends; and opposite top and bottom surfaces; and bonding the attachment edge of each of the inner and outer liquid containment beams to the interior surface, the bottom surface of each of the inner containment beams being adapted to lie against the interior surface, the bottom surface of each of the outer containment beams being adapted to lie against the top surface of one of the inner containment beams, and each of the liquid containment beams being adapted to pivot about an axis defined by its attachment edge.

38. The method of claim 37, wherein the liquid containment beams comprise from about 90 to 100 percent of the total saturated retention capacity of the absorbent article.

39. The method of claim 37 wherein the absorbent article has longitudinal and transverse axes and in the transverse direction the garment shell forms first and second outer thirds and a central third between the first and second outer thirds the attachment edges of the containment beams are bonded to the interior surface in the first and second outer thirds.

40. The method of claim 39 wherein the central third of the garment shell has a saturated retention capacity that is less than about 10 percent of the total saturated retention capacity of the absorbent article.

41. The method of claim 37, wherein the inner containment beams each comprise a plurality of individual absorbent structures in a shingled arrangement within a support layer.