Patent Publication Number: US-2003226634-A1

Title: System and process for making a disposable absorbent garment such as a diaper or training pants

Description:
BACKGROUND OF THE INVENTION  
       [0001] The present invention relates generally to a disposable absorbent garment and a process of making the same.  
       [0002] Disposable absorbent garments contemplated by the invention include disposable diapers, disposable pull-on garments, and the like. These garments are worn about the lower torso or waist of the user so as to receive and contain urine and other bodily wastes. Disposable diapers are particularly intended for use on infants who depend on a caretaker to fit the diaper. Typically, the infant is laid down while the caretaker places the garment around the waist region of the infant and then secures two ends on each side of the diaper together.  
       [0003] Disposable pull-on garments include training pants, pull-on diapers, disposable underwear, and adult incontinence garments. It is generally expected that the user of any one of these garments will be able to put on and take off the garment on his/her own. As for training pants, these garments are intended for use on a young child just before or about the time the child is ready to graduate from diapers to regular underpants (i.e., during toilet training). Training pants (and other disposable pull-on pants) have closed sides such that the user or care giver raises the garment about the user&#39;s legs to put it on and slips the garment downward about the user&#39;s legs to take it off. Thus, training pants (and other pull-on pants) are designed to be put on and taken off in the same manner by which regular underpants are put on and taken off. This feature is particularly advantageous in toilet training because it provides an early introduction to underpants and, more specifically, trains the child to wear regular underpants. Similarly, it is advantageous that the training pants fit and look very much like regular underpants so that the child is comfortable in making the transition from training pants to regular underpants.  
       [0004] The principal elements that typically make up the disposable absorbent garments described above are a liquid-permeable inner layer (or topsheet), a liquid-impermeable outer layer (or backsheet) and an absorbent core sandwiched between the inner and outer layers. Elastic members may also be incorporated into different parts of the garments. For example, elastic members may be positioned longitudinally along the diaper, generally outboard of the absorbent core to effect a seal around the buttocks, legs or both of the user. In addition, several elastic members (e.g., in the form of elongated elastic threads) may be positioned laterally throughout the waist region (including the side waist regions) of a disposable absorbent garment to allow the garment to stretch when it is put on and then during wear. In this way, the garment can stretch to accommodate variations in waist size and leg size of the user, while fitting snugly about the waist and legs and without sagging. One drawback, however, is that the elastic strands are visible on the outer surfaces of the garment and can interfere to some extent with decorative or instructional printing displayed on the outer surfaces of the garment.  
       [0005] Despite the increasing acceptance of disposable garments over the traditional cloth diapers, environmental concerns remain. A closely related issue is “source reduction” as it relates to conservation of resources. Accordingly, products which require fewer materials to accomplish the same functionality are particularly desirable.  
       [0006] Moreover, due to the high frequency of use and inherent “disposability” of disposable garments, consumers are very sensitive to the price they pay for the garments. Therefore, it is desirable for manufacturers to provide a more cost-effective disposable absorbent garment.  
       [0007] It is also known to provide disposable garments with separate side waist regions in the form of elastic side panels such as those disclosed in U.S. Pat. No. 4,938,753. The elastic side panels described therein have side edges, which are attached to the outer edges of a central absorbent core assembly. The elastic side panels may be made from various elastomeric materials or combinations thereof and provide a more uniform fit generally more snug than side waist regions having elongated elastic strands. Moreover, the elastic side panels provide outer surfaces, which are more uniform than the outer surfaces on side waist regions having elongated elastic strands. However, the elastomeric material for the side panel does not typically provide for a smooth, even outer surface when the side panels are in either the relaxed state or the stretched state. Accordingly, the side panels are not particularly conducive to having decorative or instructional printing displayed thereon. In addition, the cost of producing separate side panel products is high due to the nature of the materials and the process difficulties of handing multiple web components. Again, the cost is critical to users of disposable garments due to their high rate of use. Furthermore, the separate side panel construction inherently relies on additional seams which detract from the product&#39;s appearance, making the product look less like real underwear.  
       [0008] Alternatively, it is known to provide a unitary pair of training pants with elasticized ear flaps such as those disclosed in U.S. Pat. No. 5,246,433. The elasticized ear flaps are formed by sandwiching a relaxed elastomeric element between two material layers of the ear flaps, and adhesively attaching the material layers to the relaxed elastomeric element to form an elastic laminate. The design also calls for mechanically stretching the elastic laminate such that the material layers permanently deform. Although the side waist region according to this design generally provides a more uniform fit than a side waist region having elongated elastic strands, the outside surfaces of the side waist region are not conducive to having decorative or instructional print displayed thereon because the mechanically stretched material layers are uneven and cannot fully return to their original undistorted configuration. Other drawbacks of this and related designs include: 1) poor appearance due to deformation of materials, 2) limited range of stretch, and 3) loss of integrity of the inner and outer layers, weakening the product and forcing the use of higher strength and higher cost elastomers.  
       SUMMARY OF THE INVENTION  
       [0009] It is, therefore, one object of the invention to provide an improved disposable absorbent garment such as a diaper or adult incontinence garment, and an improved method of making such a garment and/or components of the garment.  
       [0010] Such a disposable absorbent garment is provided having a topsheet, a backsheet, and an absorbent core disposed between the topsheet and the backsheet. The topsheet, backsheet, and core together form a front region, a back region, and a crotch region disposed between the front region and the back region. To facilitate reference, the garment may be described as having a vertical longitudinal plane that extends substantially centrally through the front, back and crotch regions.  
       [0011] Preferably, each of the front and back regions includes a pair of ear portions, which extend in substantially opposite lateral directions with respect to the longitudinal plane. Each ear portion is a breathable, stretchable layer assembly. Preferably, this stretchable layer assembly includes a plurality of breathing or vent sites which are spaced from one another to present a staggered pattern of vent sites on the ear portions. At the vent sites, an outer material layer of the ear portion (e.g., an extension of the backsheet) is bonded with an inner material layer of the ear portion (e.g., an extension of the topsheet). As a result of a bonding process, such as ultrasonic bonding, vent sites are created which include a hole(s) or aperture(s) through the stretchable material layer (and through the inner material layer and the outer material layer) and through which air is passable.  
       [0012] A variation of the disposable absorbent garment is provided having a topsheet, a backsheet, and an absorbent core disposed between the topsheet and the backsheet. The topsheet, backsheet, and absorbent core form a front region, a back region, and a crotch region disposed between the front region and back regions. Further, each of the front and back regions includes a pair of ear portions extending in substantially opposite lateral directions. Each ear portion has a stretchable layer assembly of an outer material layer, an inner material layer, and a stretchable member or material layer secured therebetween. The outer material layer is an extension of the backsheet and extends laterally to form, at least partially, a side edge of the ear portion (i.e., side edge of the garment). Similarly, the inner material layer is an extension of the topsheet and extends laterally to also form, at least partially, a side edge of the ear portion. Accordingly, an ear portion may be formed that is seamless (i.e., along the outer and inner surfaces) as well as stretchable.  
       [0013] Preferably, the topsheet is a three-piece topsheet assembly consisting of a central section (including a portion generally disposed over the core) and a pair of side or outer sections which form or provide the inner material layers of two of the ear portions (e.g., for the two ear portions or the two right ear portions). Moreover, the garment may include a longitudinally-extending, preferably elasticized, leg cuff spaced in generally parallel relation from each lateral side of the core. The leg cuff may include an outer material, section or layer that is formed from the topsheet (e.g., topsheet side or outer section) and an inner material, section or layer that is substantially impervious.  
       [0014] Further yet, the stretchable material layer may be one that is extendible between a contracted configuration and an extended configuration and is preferably secured to the outer material layer when the stretchable material layer is disposed in the extended configuration. As a result, the outer material layer is subsequently contractible then extendible with the stretchable material layer (and, more particularly, its outer surface is returnable to a substantially smooth and planar configuration).  
       [0015] The garment employs relatively fewer number of materials and components than is typical of prior art garments and is relatively less expensive to produce. Such attributes are particularly important in products such as diapers and training pants which are consumed by users at a high rate. As compared to prior art products with side panels, the present invention provides a garment with stretchable ear portions or layers which are seamless and thus have a more desirable appearance which employ fewer components and relatively easy to construct. As a result, these garments are relatively less costly and more comfortable to wear. Further, the garment is relatively lighter than prior art garments, and thus more comfortable to wear.  
       [0016] Yet another variation of the disposable absorbent garment is one having a topsheet, a backsheet, and an absorbent core disposed between the topsheet and the backsheet. The topsheet, backsheet, and the absorbent core also form a front region, a back region, and a crotch region disposed between the front and back regions. Each of the front and back regions includes a pair of ear portions extending in substantially opposite lateral directions. The garment further includes a longitudinally extending leg cuff spaced, in generally parallel relation, from each lateral side of the core. The leg cuff has a first layer formed from a substantially impervious material (e.g., preferably a hydrophobic material such as a polymeric material) and a second layer formed from the topsheet. It is to be understood that the first and second layers of the leg cuff may also be referred to as cuff sections, cuff material or surface, cuff wall and like structure.  
       [0017] For purposes of the present descriptions of the invention, the term “impervious” means impervious to liquid passage. Also, the term “breathable structure” means a structure that substantially allows air to pass therethrough.  
       [0018] The garment may also include a pair of longitudinally extending leg cuffs, wherein each leg cuff is spaced from a lateral side of the core. Further yet, the garment includes a substantially impervious containment structure or barrier defined by the polymeric layer and a pair of substantially impervious sections (e.g. a polymeric side section), extending from one of the leg cuffs to sealingly engage the polymeric layer. Each leg cuff has an outer barrier layer and an inner barrier layer that is a portion of one of the substantially impervious sidewalls. Moreover, the containment structure forms a continuous and substantially impervious barrier (e.g., against core leakage) around the core (i.e., except above the core wherein the waste is received).  
       [0019] A method of forming a breathable, stretchable section of a disposable absorbent garment, such as a stretchable side panel or ear region, is also described in detail herein. The method includes steps of selecting a first material for a first material layer (e.g., a topsheet nonwoven material) and a second material (e.g. a backsheet nonwoven) for a second material layer, whereby the first and second material layers are bondable by an ultrasonic bonding process, and selecting an elastic material (e.g., an elastomer) for a stretchable material layer. The stretchable material layer is positioned between the first and second material layers to form a layer assembly, then one or more bond sites on the layer assembly are targeted for bonding one or more of the material layers together. The method then calls for securing the first, second, and stretchable layers together by ultrasonically bonding the first material layer with the second material layer at the one or more sites. Accordingly, an aperture is formed through the stretchable material and the first material layer and the second material layer bond through the aperture, such that the aperture provides a breathable passage therethrough. In a further variation, the targeting step includes longitudinally and laterally spacing the bond sites so as to create a staggered pattern of breathable bond sites on the stretchable section of the garment. This staggered pattern allows for maximum contracted (minimum relaxed) dimensions thus maximizing the fit range of the product.  
       [0020] A stretchable section is therefore produced that provides improved comfort and functionality, among other attributes. The method may be employed to form various sections of the garment including an ear portion or waist portion.  
       [0021] In one method according to the invention, a composite web structure is formed that is finishable to form a disposable absorbent garment. This method includes the steps of providing a core assembly and forming a topsheet assembly having a pair of longitudinally-extending, elasticized leg cuffs. The method further includes applying the topsheet assembly on the core assembly to create a first web structure assembly. Also, a backsheet assembly is formed that includes a backsheet material and this assembly is applied on the first web structure assembly to form a second web structure assembly. This second web structure assembly can then be cut at one or more locations to form the composite web structure.  
       [0022] Preferably, the step of forming a topsheet assembly includes the steps of: providing two webs of the topsheet material and two webs of elastic material to form two subsequent webs; providing a first web and a second web of the polymeric liner material, respectively; applying each web of elastic material onto one of the webs of topsheet material; and applying the first web of polymeric liner material onto one of the webs of topsheet material and the second web of polymeric liner material onto the other web of topsheet material. Each web of polymeric liner material is applied adjacent a web of the elastic material, and such that the subsequent folding step creates a leg cuff having one layer of the topsheet material, a second layer of the polymeric liner material, and elastic material there between.  
       [0023] Further, the step of forming a topsheet assembly may include providing a third web of a topsheet material and centrally applying the third web of topsheet material so as to engage each of the assemblies having elasticized leg cuffs to form a web of a topsheet assembly having a pair of topsheet side sections and a topsheet central section provided by topsheet material from the third web. The web of topsheet assembly is cut to form a discrete -topsheet assembly, before the step of applying the topsheet assembly onto the first web structure. Further yet, the method may include the steps of providing a polymeric film material and applying the film material to the core assembly such that the first web structure includes a topsheet assembly above the core and polymeric film material beneath the core. Accordingly, the step of forming a topsheet assembly includes providing a pair of longitudinally-extending leg cuffs, each cuff having a cuff layer formed by a portion of a polymeric liner attached thereto. In one aspect of the inventive method, the free edge of each polymeric liner is applied so as to sealingly engage with the film material to create a substantially impervious containment structure about the core.  
       [0024] It should again be noted that the invention is adaptable to various types of disposable absorbent garments including, but not limited to, disposable diapers, training pants, adult incontinence garments and other pull-on garments.  
       [0025] These and other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description and the drawings.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0026]FIG. 1 is a perspective view of a disposable absorbent garment according to one embodiment of the present invention shown as it would appear worn around the waist region of a user;  
     [0027]FIG. 2 is a top plan view of a composite web structure of a disposable absorbent garment shown unfolded and extended with portions cut away to reveal an underlying structure;  
     [0028]FIG. 3 is an exploded view of the disposable garment of FIG. 2;  
     [0029]FIG. 4 is a cross sectional view through line  4 - 4  in FIG. 2;  
     [0030]FIG. 5 is a cross sectional view of the garment in FIG. 4 shown in a relaxed, non-extended configuration;  
     [0031]FIG. 6 is a bottom plan view of a portion of a side waist region of the garment in FIG. 4;  
     [0032]FIG. 6A is a close-up view of a portion in FIG. 6;  
     [0033]FIG. 7 is a bottom plan view of a portion of a side waist region in FIG. 4 shown in a contracted configuration; and  
     [0034]FIG. 8 is a diagrammatic view of a system for assembling a composite web structure according to the-invention. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
     [0035]FIG. 1 depicts a disposable absorbent garment  10  embodying the invention and in the form of a training pant or adult incontinence garment. The garment  10  is formed with a waist opening  12  and two leg openings  14 , and is shown, as it would appear worn about the lower torso or waist region of a user. FIG. 2 depicts a composite web structure  10   a  of the garment  10  in a flat and unfolded configuration, which it assumes during one point in the manufacturing process when it is stretched in both the lateral and longitudinal directions. As will be further explained below, the web structure  10   a  may be subsequently trimmed, folded, sealed, welded and/or otherwise manipulated to form a disposable garment  10  in final form and for packaging. In this regard, the composite web structure  10   a  is referred to as being finishable to form a disposable absorbent garment. In particular, the view of FIG. 2 is provided to reveal with clarity most of the major elements of the disposable absorbent garment  10  and/or web structure  10   a  according to the present invention.  
     [0036] It should first be noted that, upon review of the detailed description and the drawings provided herein, it will become apparent to one of ordinary skill in the art that the present invention is also applicable to other disposable absorbent articles and, more particularly, to disposable absorbent garments other than training pants and adult incontinence garments. The present invention is not intended to be limited to the structures and processes specifically described and illustrated herein.  
     [0037] Referring to FIG. 2, the garment  10  features a layered assembly or composite web structure  10   a  that includes a liquid-permeable inner layer or topsheet  16 , a backsheet assembly including a hydrophobic and liquid permeable nonwoven backsheet  18  and a liquid-impermeable poly film barrier  60 , and an absorbent core  36  disposed therebetween. The web structure  10   a  may be described further with reference to a longitudinally extending central axis A and a laterally or transversely extending central axis B. Along the longitudinal axis A, the garment  10  features a front waist region  20  having a front edge or front longitudinal end  52 , a back waist region  22  having a back edge or back longitudinal end  54 , and a crotch region  24  extending between the front waist region  20  and the back waist region  22 . Along the lateral direction, the garment features left ear region  26 a, central body region  28 , and a right ear region  26 b. Similarly, the back waist region  22  includes a left ear region  26 a, a central body region  28 , and a right ear region  26 b. An elasticized leg cuff  38  extend between the front waist region  20  and the back waist region  22  on either side of the absorbent core  36 . Described further below, the leg cuffs  38  or at least a portion of the leg cuffs  38  are formed between the ear regions  26 a,  26 b and the waist regions  20 ,  22 .  
     [0038] The web structure  10   a  also has a longitudinal side edge  88  that extends between each pair of ear regions  26   a ,  26   b  and is spaced on each side of the absorbent core  36 . As shown in FIG. 2, the side edges  88  are not straight lines but includes curves which help form the generally hourglass shape of the composite web structure  10   a . Further, each of the ear regions  26  has a side edge area  30 . During a later stage in the manufacturing process, the pair of ear regions  26   a  are joined together by mating their respective side edges  30  so as to form a side seam  34  (see FIG. 1) and a leg opening  14 . The ear regions  26 b are similarly joined to form a second side seam  34  and a second leg opening  14 , and also to form a waist opening  12 . It should be understood that the pair of ear regions  26   a  or  26   b  may be joined together by employing procedures well known to those skilled in the art (e.g., by ultrasonic welding, thermal bonding, or use of an adhesive).  
     [0039] When the garment  10  is properly worn about the waist region of the user, the topsheet  16  (and leg cuffs  38 ) generally contacts the buttocks of the user while the backsheet  18  faces outwardly from the body of the user. Further, the front waist region  20  of the garment  10  is situated at the front waist area of the user and the back waist region  22  is situated at the back waist area of the user, while the crotch region  24  is situated between the legs of the user and at the crotch area. As for the ear regions  26 , each pair of adjoined ear regions  26   a ,  26   b  is designed to fit snugly about the side waist region of the user with the side seams  34  positioned preferably in a substantially vertical orientation.  
     [0040] As used herein for the purpose of description, each of the term “backsheet”, “backsheet assembly, or “outer layer of the garment” refers to any sheet, layer or composite that covers at least the core  36 , but preferably extends laterally beyond the core  36  toward the side edges  30  and longitudinal side edges  88  of the garment  10  or web structure  10   a . Further, the term “backsheet”, “backsheet assembly” or “outer layer of the garment” may refer to any assembly, unitary or integrally, of sheets, layers, or composites applied at least over the core  36 , and any part, portion, region or section thereof. For example, the backsheet may have applied thereon a film material and/or graphics. The backsheet and film material may be referred to as one structure or as individual structures or layers.  
     [0041] The backsheet  18  may be constructed from a number of different suitable materials and, preferably, may have a breathable or vapor-permeable attribute (distinguishing it from liquid-permeable) so that air can pass therethrough. In the embodiment of FIGS.  1 - 8 , the garment  10  (or web structure  10   a ) is equipped with a “backsheet-polyassembly” comprising a backsheet material  18  of a hydrophobic and vapor-permeable nonwoven material and a poly film mask of film barrier  60  that is laminated or otherwise applied onto the backsheet material  18  (see FIG. 3). In various embodiments, the film barrier  60  may or may not be vapor-permeable. Preferably, the film barrier  60  may be applied as a mask or sheet in a central area of the web structure  10   a , as shown in FIG. 3. The film barrier  60  has an overall width that is less than the width of the other backsheet materials but sufficiently wide to cover the absorbent core  36 .  
     [0042] One suitable construction for the backsheet assembly  18  includes an outer layer of spunbond polypropylene fiber with a basis weight of about 15 gsm (available from BBA Nonwovens, of Simpsonville, S.C.) and a polyethylene film of about 0.5 mil (0.0005″) thickness adhesively laminated to the outer layer. Such a polyethylene film is available from, and manufactured by, Exxon Chemical USA, of Houston, Tex. The film may be laminated using adhesive available from National Starch &amp; Chemical Company of Bridgewater, N.J. Yet another suitable construction for the backsheet  18  includes a web of spunbond or SMS (spunbond\meltblown\spunbond) nonwoven material and breathable or non-breathable films of 0.5 mils to 2.0 mils in thickness.  
     [0043] As shown in FIG. 3, the backsheet  18  is a sheet that provides the outer layer of each of the ear regions  26  as well as the outer layer of the rest of the front and back regions  20 ,  22  and the crotch region  24 . Thus, the outer layer of each ear region  26  may be referred to as being unitary with, and forming a lateral extension of, the rest of the backsheet material. The backsheet  18  therefore extends up to and forms, at least partially, a side edge of the ear regions  26  and the web structure  10   a.    
     [0044] In an alternative embodiment, the backsheet  26  may include a central section and a pair of left and right side panels or sheets which are distinct from the central section. Each of the side panels is joined to and, thereby, integrated with the central section. The left side panel extends between each of the left ear regions  26   a  and provides an outer layer common to both ear regions  26   a . Similarly, the right side panel extends between each of the right ear regions  26   b  and provides an outer layer common to both right ear regions  26   b . In yet another embodiment, the backsheet  18  includes, in addition to a central section, four separate side panels: a front right ear panel, a back right ear panel, a front left panel, and a back left panel. Each of the panels forms an outer layer of an ear region  26  and is joined to, and integrated with, the central section of the backsheet  18 .  
     [0045] The absorbent core  36  is generally elongated and rectangular in shape. As best shown in FIG. 2, the core  36  is generally centered about the longitudinal axis A and laterals axis B of the garment  10 , and firmly secured between the topsheet  16  and backsheet  18 . The core  36  is preferably made of an absorbent composition adapted to absorb bodily liquids received through the topsheet  16 . Typically, the absorbent composition includes a fluffed wood pulp component for wicking and structural integrity and a high absorbency material (or super absorbent) for containing liquids. However, the garment  10 , according to the present invention, is equally adapted to utilize absorbent cores of varying shapes and compositions, as well as other types of cores known in the art.  
     [0046] As used herein for purposes of description, the term “topsheet”, “topsheet assembly” or “inner layer of the garment” may refer to any sheet, layer or composite that covers at least the core  36 , but preferably extends beyond the core  36  toward the side edges  30  and longitudinal side edges  88  of the garment  10  or web structure  10   a . Further, the term “topsheet”, “topsheet assembly ” or “inner layer of the garment” refers to any assembly, unitary or integrally, of sheets, layers, or composites applied at least over the core  36 , and any part, portion, region or section thereof.  
     [0047] The topsheet  16  may be constructed from a wide range of suitable materials including nonwoven webs of natural fibers (e.g., wood or cotton) or synthetic fibers (e.g., polypropylene or polyester), a combination of such webs or fibers, or apertured film. One suitable topsheet material is a 15 gsm spunbond polypropylene from Avgol Nonwoven Fabrics of Holon, Israel. In addition, the topsheet  16  may be treated with a surfactant to facilitate liquid transfer, especially at a central zone of the topsheet  16  over the core  36 , and an inner surface of the topsheet  16  may be treated with a chemical to increase the surface tension of liquid passing through the material.  
     [0048] Referring to the web structure  10   a  of FIG. 3 and also FIG. 4, the topsheet  16  may be formed from a three-piece structure including a center section  16   a  disposed above (but not necessarily directly above) the absorbent core  36  and two lateral side sections  16   b  each laterally extending from the center section  16   a . The lateral end or edge sections  88  of the lateral side sections  16   b  form the lateral ends or edges  88  of the web structure  10   a  (and of the ear portions  26 ). Referring to FIG. 4, the proximal end or edge sections of lateral side sections  16   b  are turned upwardly and provide an inwardly folded edge  90 . These proximal edge sections  90  form an outer layer or outer cuff section  38   b  of leg cuff  38  that is joined with a substantially hydrophobic and impervious inside (or inner) layer or inside cuff section  38   a  of the leg cuff  38 .  
     [0049] The inside cuff section  38 a is preferably formed from a substantially hydrophobic and impervious material substantially similar to or the same as the polymeric material from which the film barrier  60  is made. Referring to the cross sectional view of FIG. 4, the inside cuff section  38 a extends downwardly from the folded edge so as to engage an outer edge of center section  16   a  (near the top of the core  36 ) and, then, further downwardly to engage the film barrier  60  (near or below the bottom of the core  36 ). The inside cuff section  38   a  of the leg cuffs  38  may engage each of the outer edge of the central section  16   a  of the topsheet  16  and the film barrier  60  by adhesive or welding means and other joining means. Since the film barrier  60  and the inside cuff section  38   a  can be formed from the same substantially hydrophobic and impervious material, these two components may be easily integrated as one piece or applied as one piece in the manufacturing process.  
     [0050] Further, because the inside cuff sections  38   a  are connected to, integrated with or otherwise sealingly engages the film barrier  60 , a continuous and substantially hydrophobic and impervious “bathtub-like” containment structure or barrier is formed under and on both sides of the absorbent core  36 . The bottom and side walls of this bathtub-like containment structure is provided by the film barrier  60  and the pair of inside cuff sections  3   8 a respectively. Accordingly, the inventive garment  10  features a unique containment structure that significantly reduces the possibility of leakage from the core area of the garment  10 . In particular, the engagement of the side wall or inside cuff section  38 a with the bottom or film barrier  60  of the bathtub-like containment structure prevents migration of waste (from the area of the core  36 ) underneath the cuff  38  toward the sides of the garment  10 .  
     [0051] The leg cuffs  38  are preferably positioned on either side of or spaced from longitudinal axis A and outboard of the core  36 , and extends generally upwardly from the topsheet  16  (i.e., toward the user). The longitudinal ends of the cuffs  38  may be attached, for example, to the topsheet  16  in the front and rear waist regions  20 ,  22 . Preferably, the ends of the leg cuffs  38  are tacked down inwardly and attached, for example, by adhesive, to the web structure  10   a . Such a construction biases the cuff  38  inwardly and is generally considered to cause the cuff  38  to exhibit improved leakage prevention properties.  
     [0052] Preferably, the leg cuffs  38  are equipped with one or more elastic material layers or members  40 , which extend along a substantial length of the leg cuffs  38 . In a common application, the elastic members  40  are placed within or underneath the leg cuffs  38  while in a stretched condition and then glued to the cuff at least at their ends. When released or otherwise allowed to relax, the elastic members  40  retract inwardly. When the garment  10  is worn, the elastic members  40  function to contract the leg cuffs  38  about the buttocks of the user in a manner, which effects a seal between the garment  10 , and the buttocks.  
     [0053] The leg cuffs  38  ( or at least the outer cuff section  38 b) may be formed by a number of alternative methods known in the art. One method involves gluing a separately constructed leg cuff or cuff section to the top surface of the web structure  10   a . Another method requires forming the leg cuff or cuff section from the topsheet or the backsheet  18 . Yet another method involves creating and folding noodle cuffs as disclosed in U.S. Pat. No. 5,536,350, which is hereby incorporated by reference.  
     [0054] In an alternative embodiment of the invention, a longitudinally stretchable leg gather is positioned proximately each longitudinal side edge  88 . When the garment  10  is properly worn by the user, each leg gather encircles a leg of the user and effects a seal thereon to prevent leakage. Generally, the leg gather is formed with elastic members which are typically applied in the stretched or extended condition and are placed between the topsheet  16  and backsheet  18 . The elastic members are glued or otherwise secured to one or both of the topsheet  16  or backsheet  18 , or other material layer of the web structure  10   a . Upon release from its stretched condition, the elastic members retract with the attached material layer and form gathered leg regions.  
     [0055] The present invention is adapted to use other leg gather constructions known in the art. Moreover, the present invention may utilize leg gathers in combination with leg cuffs  38  as described above or, alternatively, alone without leg cuffs.  
     [0056] As best shown in FIGS. 2 and 3, the web structure  10   a  and thus, the disposable absorbent garment  10 , preferably includes, disposed between the central section  16   a  and core  36 , an acquisition layer  48  and top tissue layer  47 . The acquisition layer  48  (or surge layer) is preferably situated between the topsheet  16  and the core  36 . One function provided by such an acquisition layer  48  is to spread out or dispense liquid flow received by the garment  10  so that liquid is distributed more evenly over the surface of the core  36 . By slowing down the liquid flow, the core  36  has sufficient time to absorb the liquid received thereon. The acquisition layer  48  also serves to prevent the situation wherein the core  36  is saturated locally, while a substantial remainder of the core  36  is not absorbing liquid.  
     [0057] Therefore, FIG. 3 provides a cross-sectional view which depicts the various layers of the web structure  10   a  and the respective structural relationships of the layers. In further embodiments, the inventive garment  10  may utilize a multi-purpose material as one of the layers. Such a multi-purpose material would then provide multiple functions, thereby eliminating the need for one or more of the above-described layers.  
     [0058] As best shown in FIGS. 2 and 3, the web structure  10   a  and thus, the disposable absorbent garment  10 , is also equipped with an elastic waist band  44  that is inserted between the topsheet  16  and backsheet  18  and adjacent the central body regions  28  of each of the front waist region  20  and back waist region  22 . In other forms of the invention, the waist band  44  may be omitted or may be extended substantially continuously along the top end of the front waist region  20  and back waist region  22 , thereby encircling or partially encircling the waist of the user when the garment  10  is worn. The waistband  44  is preferably made of an open cell urethane foam materials available from General Foam, of Paramus, N.J.  
     [0059] Still referring to FIGS. 2 and 3, the web structure  10   a  of disposable absorbent garment  10  is further equipped with a stretchable material layer or member  46  (e.g., an elastic member) substantially incorporated with, and made a part of, one or more of the ear regions  26 . As best shown in FIG. 3, the stretchable member  46  is preferably interposed between the topsheet  16  and backsheet  18  in the ear regions  26 . The stretchable member  46  extends longitudinally from nearly adjacent a longitudinal end  52  towards the crotch portion  24  (i.e., about 5-6″ long) and laterally from substantially proximate the central body portion  28  toward the side edge area  30 . However, the stretchable member  46  should be spaced sufficiently inwardly from the side edge area  30  so as not to be affected by or to affect the attachment of the side edges  30  to one another to form the garment  10 . Furthermore, the present invention is not limited to specifically sized or positioned stretchable members  46 . Instead, the stretchable member  46  may assume a variety of shapes and sizes and may be positioned at various locations within the ear regions  26  as long as the stretchable member  46  provides the ear regions  26  with sufficient extensibility to accomplish joinder of the ear regions  26  to form a waist region.  
     [0060] When the ear regions  26  are joined by the welding/bonding process, there is formed an absorbent garment  10  having stretchable side waist regions formed by the pairs of ear regions  26   a ,  26   b . The stretchable member  46  is designed and is positioned within the ear regions  26  to facilitate stretching of the ear regions  26  in the lateral direction. The garment  10 , therefore, can extend around and contract toward the side waist region of the user, and effect a snug fit. In one alternative embodiment of the invention, a substantially continuous elongated stretchable member  46  is positioned along both the front waist region  22  and back waist region  20 , thereby acting as a nearly continuous belt around the user. The continuity of the belt is interrupted only by the side seams  34 . In such an embodiment of the invention, the foam waistband  44  is preferably eliminated.  
     [0061] In a unique aspect of the invention, the ear regions  26  are attached to the stretchable member  46  when the stretchable member  26  is in a stretched or extended configuration. In forming an ear region  26 , the stretchable member  46  is first extended or otherwise stretched laterally and then the inside surface of the topsheet material and/or backsheet material at the ear region  26  is\are secured or otherwise attached to a corresponding surface of the stretchable member  46  by conventional adhesive or mechanical means. It is important to extend the sheet material(s) to an extent where it displays a smooth, flat outer surface, but not necessarily to the extent where the material stretches and/or deforms. When the stretchable number  46  is then allowed to contract or relax, the topsheet material and/or backsheet material contracts with it.  
     [0062] To illustrate, FIG. 4 depicts the ear region  26  having an outer layer provided by the single-sheet backsheet material and formed unitary with the rest of the backsheet  18 , and an inner layer provided by the leg cuff lateral section  16   b  of the topsheet  16 . The ear region  26  is shown immediately after a section of both the lateral section  16   b  and the backsheet  18  are attached to the stretchable member  46  (and also when the garment  10  is worn by the user). In this view, the stretchable member  46  is maintained in the stretched or extended configuration, and the top lateral section  16   b  and backsheet  18  each display flat, smooth outer surfaces  90 ,  92  respectively. FIG. 5 depicts the ear region  26  after the stretchable member  46  is released and allowed to contract laterally to a relaxed, contracted or unscratched configuration. Preferably, the stretchable member  46  contracts from an initial width of about 4-½″ to 5-½″ to a relaxed or contracted width of about 2″ to 3″. The layered composite or assembly that is formed by the leg cuff lateral sections  16   b , backsheet  18  and stretchable member  46  is moved inwardly toward the leg cuff  38  and, as a result, the lateral width of the garment  10  is reduced (e.g., from about 15″ to 16″ across to about 11″ to 12″ across). Moreover, the outer surface  90  of the lateral section  16   b  and the outer surface  92  of the backsheet  18  are slacked and form wrinkles and undulations on both sides of the stretchable member  46  (i.e., exhibit gathers).  
     [0063] To further illustrate, the bottom plan view of FIG. 6 is provided to show the condition of the backsheet  18  when the stretchable member  46  (and the stretchable ear portion  26 ) is disposed in an extended or stretched configuration (e.g., when the garment  10  is worn by the user). In the extended configuration, the backsheet  18  displays a smooth, continuous outer surface  92 . Thus, when the garment  10  is worn around the waist of the user, the front and back waist regions  20 ,  22  together display a continuous, smooth outer surface substantially all around the waist of the user except where it is interrupted by the side seams  34 . Conversely, FIG. 7 is a bottom plan view showing the condition of the backsheet  18  when the stretchable member  46  is disposed in the contracted or unstretched condition (e.g., when the garment  10  is not being worn by the user). In this view, wrinkles and a series of undulations (i.e., exhibits gathers), characterize the outer surface  92  of the backsheet  18  at the ear region  26 .  
     [0064] It should be further noted that neither the side section  16   b  nor the backsheet  18  is permanently elongated during the forming of the composite layer, or during normal subsequent wear. In other words, the topsheet  16  and backsheet  18  are not stretched beyond its elastic region, and in some processes are merely extended to smooth out the outer surface, but not stretched beyond that point. In summary, the topsheet  16  (i.e., top cuff  16   b ) and backsheet  18  are merely stretched or extended to form flat, smooth surfaces  90 ,  92  during manufacturing and when the garment  10  is worn about the user, but retracts to a wrinkled, contracted state when the garment  10  is otherwise not worn.  
     [0065] The stretchable member  46  may be formed from an elastic material, such as the material typically used for the elastic waistband  44 , or any other material with the appropriate stretch and return properties. The stretchable member  46  may be also formed from a heat-activated elastomeric material or elastomer that is elasticized upon initial application of a predetermined amount of heat. The heat-activated elastic also contracts from an extended configuration to a contracted condition upon the initial application of heat in the vicinity of the stretchable member  46 . In a process which makes use of the heat-activated elastomer, sections of the topsheet  16  and backsheet  18  are fastened to opposite surfaces of a stretchable member  46  incorporating the heat-activated elastomer and then contract with the stretchable member  46  upon the initial application of heat to the elastic. The stretchable member  44  incorporating the heat-activated elastomer may stretch or extend laterally when the garment  10  is worn around the waist of the user and then retract to its contracted, relaxed or unscratched configuration when the garment  10  is not being worn. Further, the materials of the leg cuff lateral section  16 b and the backsheet  18  can extend laterally with the stretchable member  46  to display flat, smooth outer surfaces  90 ,  92  at the ear regions  26  and then contract with the stretchable member to display outer surfaces  90 ,  92  characterized by wrinkles and a series of undulations, and exhibiting gathers.  
     [0066] Preferably, the stretchable member  46  is applied by first extending or stretching the stretchable member  46  laterally and then securing (or otherwise attaching) the inside surface of the topsheet material and/or backsheet material to the corresponding surface of the stretchable member  46  (which is in the stretched condition). This latter procedure may be implemented by a mechanical thermal bonding process such as ultrasonic or heat and pressure bonding practices, and, more preferably, by ultrasonic bonding process.  
     [0067] In any of the above bonding processes, the topsheet  16  is mechanically bonded to the backsheet  18  at localized bond sites or bond points  100 , at which the topsheet  16  and backsheet  18  are joined together through the stretchable member  46  (see FIGS. 6 and 7). Preferably, an ultrasonic bonding process is employed to bond the topsheet  16  and the backsheet  18 , through the stretchable member  46 . Employment of this bonding process, creates holes or apertures at the bond sites  100  and through the stretchable member  46 .. These holes or apertures at the bond sites  100  provide breathability or air permeability to the ear regions  26   a ,  26   b  (see also FIG. 6). More particularly, the holes at the bond sites  100  are created as a result of the selection of materials for the topsheet  16 , backsheet  18  and stretchable member  46 , and use of the ultrasonic bonding process. In this process, the non-woven materials (i.e., topsheet  16  and backsheet  18 ) requires substantially more energy to bond than the material selected for the elastic member  46  (i.e., a polymeric material). Accordingly, the level of ultrasonic bonding that is sufficient to bond the non-woven materials also causes the material for the elastic member  46  to fracture and/or disintegrate. As a result, the two non-woven layers bond together, but trap the polymeric material of the elastic member  46  therewith. Further, the hole that is blown or created through the elastic member  46  is larger than the bond site, and the two non-woven layers bond with each other through the center of the hole.  
     [0068] Furthermore, the inventive garment and manufacturing process provide a pattern for placement of the bond sites  100  on the ear region  26   a ,  26   b . The preferred pattern is a staggered pattern as shown in FIG. 6 which maximizes the spacing between bond sites  100  for a given number of bond sites  100 . Importantly, the spacing between consecutive bond sites along direction of stretching (i.e., lateral direction) is maximized such that the elasticity of the ear region in this direction is not significantly altered nor compromised. A breathable ear region or side panel is, therefore, provided having adequate elastic properties and contracting force.  
     [0069] Although, the bond sites or holes may be formed in any shape, it is preferred to select a shape that is particularly adapted to staggering, such as the rectangular shape shown in FIG. 6. Such a shape, wherein the longitudinal dimension is significantly greater than the lateral dimension, provides a larger capacity for stretching in the lateral direction while minimizing the potential for propagating tears.  
     [0070]FIG. 8 illustrates, in simplified form, one embodiment of the apparatus or system  111  for manufacturing the garment  10 , according to the invention. FIG. 8 also illustrates a method of manufacturing a training pants garment  10  in the “in-line” or “machine” direction. The terms “in-line direction”, “in process direction”, and “machine direction” are used herein to refer to an orientation and travel of the composite web structure during the manufacturing process. When oriented in the “inline”, “in process” or “machine” direction, the front or back waist regions is positioned ahead of the crotch region in the direction of conveyor travel with the other waist regions directly trailing the crotch region. This is different from the cross-machine orientation wherein the web structure is turned  90  degrees from the in-line or machine direction such that the crotch region and the waist regions are aligned along a lateral line that is normal to the direction of conveyor travel. One feature of the inventive system and method is the assembly of a composite web structure as the web structure travels in the in-line direction and, further, the delivery of a three-piece top sheet already equipped with a pair of elasticized polycuffs onto such a composite web structure.  
     [0071] Referring to FIG. 8, the method preferably involves the conveyance of the composite web structure  10   a  from left to right in the Figure and in the in-line direction C. The method may be regarded as beginning with the delivery of a continuous web structure  100   a  comprising of an absorbent core, top tissue and acquisition layer (e.g., core assembly). Typically, the absorbent core is received from a drum former, delivered to a transfer roll and then onto a surface of a main conveyor  70  moving from left to right. Each absorbent core is positioned on the conveyor  70  such that its length is generally parallel to the machine direction C. It should be noted, however, that the present inventive method is adapted to employ any suitable manner known in the art of depositing absorbent cores onto the conveyor  70  and/or delivering the composite web structure  10   a.    
     [0072] The method further includes the use of a supply roll to continuously apply or otherwise provide the top tissue layer onto each absorbent core  36 . Downstream of the supply roll, another supply roll and a cut and slip unit are situated. These units are conventional types which are readily available to one skilled in the art. The supply roll delivers the acquisition layer material to the cut and unit to form individual patches of the material which are spaced apart and then applied on top of the top tissue. This step therefor provides an acquisition layer on the composite web structure  10 a. A continuous web structure  10   a  is thereby formed comprising absorbent core, top tissue and acquisition layer and is oriented in the in-line direction.  
     [0073] Next, this continuous web is moved toward the pad knife or cutting roll which is used to cut the composite web structure  10   a  laterally between the absorbent core. Accordingly, this cutting step provides a plurality of individual, in-line composite web structures  10   a  comprising absorbent core covered with top tissue and acquisition layer. A supply roll positioned downstream of the pad knife such that, as each web structure  10   a  is conveyed thereto, a polymeric layer is applied or provided onto the bottom of the absorbent core. Application of the polymeric layer forms the film barrier layer beneath the absorbent core.  
     [0074] Upon or simultaneous with the step of applying the film barrier layer is the step of applying a three-piece topsheet assembly equipped with poly-on, elasticized leg cuffs onto the web structure  100   a , as shown in FIG. 8. A composite structure  49  including this topsheet assembly is constructed in a separate process or subprocess before it is delivered to the main conveyer  70  and applied to the top of the composite web structure  10   a . The composite structure  49  is preferably formed by employing a subsystem  111   a  that is separate from but interconnected with the conveyor  70 .  
     [0075] Referring to the subsystem  111   a  in FIG. 8, a continuous web of topsheet material  16   b  is first slit along its centerline so as to create two webs of equal dimension. The two webs are then presented by way of rollers  130 , to a combining roll  90 . Simultaneously, a continuous web of poly-liner material  38   a  is slit along its centerline so as to create two webs of equal dimension. These two webs are also presented by way of rollers  132  to the combining roll  90 . Further, a continuous web of elastic strands  40  is presented to the combining roll  90  and is attached, by glue or other means, with the two webs of topsheet material  16   b  and the two webs of poly-liner material  38   a . In the resulting web structure  134 , the elastic strands  40  are positioned under the joining area of the topsheet  16   b  and the poly-liner  40  and glued thereabout. Using a folding board  101 , a small edge of each topsheet material  16   b  is folded over each poly liner  40  so as to close the distal edge of each cuff  38 .  
     [0076] Next, a second continuous web of topsheet material  16   a  is presented to the two webs of folded topsheet-cuff structure  134 . The proximal end of each leg cuff  38  is combined with the two opposite side edges of the second continuous web of topsheet  16   a  (i.e., to form the center section of the topsheet), using glue or other methods known in the art. This forms a continuous composite web structure  49  or three-piece topsheet having therewith a poly-lined leg cuff  38 . This composite web structure  49  is then delivered to the conveyor  70  via roller  103 , as described above.  
     [0077] When the composite web structure  49  of three-piece topsheet having poly-lined leg cuff  38  is attached to the web structure  10 , the polyliner  38   a  is joined with or otherwise engages opposite side edges of the barrier film  60 . This engagement between the two substantially hydrophobic and impervious layers results in the bathtub-like containment structure disposed at least adjacent the bottom and sides of the core  36 , as described above.  
     [0078] In what may be regarded as the next stage of the process, a web structure  50  including backsheet  18  and stretchable members  46  is then applied to composite web structure  10   a . This web structure  50  is constructed from a subprocess employing a subsystem  113  which is separate from but converges onto the conveyor  70 . This subprocess begins with the step of providing a continuous web of backsheet material  18  and applying an adhesive thereon, and then delivering the backsheet material  18  to a vacuum drum  80 . A continuous web of the stretchable member  46  (e.g. elastomeric film layer) is slit into two webs. Each of the two webs is then stretched to about their full elasticity in the lateral or cross machine direction and presented to the vacuum drum  80 . As the vacuum drum  80  rotates the two stretched elastomeric films  46 , the drum  80  applies the stretched films  46  onto the opposite edges of the backsheet material  18 . Action by both the adhesive and the vacuum (from the vacuum drum) hold the elastomeric film  46  in the stretched position on the backsheet  18 . Importantly, when the stretchable member  46  contacts the backsheet material  18 , the stretchable member  46  is disposed in the stretched condition and the backsheet material  18  is extended in both the lateral and longitudinal directions, such that its inside and outside surfaces are smooth and substantially planar. After the addition of adhesive, the drum  50  rotatably carries and delivers the stretched composite web structure  50  to the conveyor  70 . At the conveyor  70 , the web structure  50  is applied to the bottom web structure  100   a  so as to form a lamination therewith.  
     [0079] A stretched ear region or side panel is, therefore, created that is made up of an elastomeric film  46  laminated between the full width backsheet  18  and the full width topsheet  18 . In this respect, an elastic side panel or ear region becomes an integral part of the complete absorbent garment. As mentioned above, adhesive may be applied on the backsheet material  18  and/or the stretchable member  46  prior to these two elements coming into pressurized contact.  
     [0080] In a subsequent step in the inventive process, the web structure  10   a  is conveyed to a thermal-bonding module  81  (e.g. employing ultrasonic or heat and pressure bonding practices). At the module  81 , the composite webs  50 ,  49  are bonded together and through the stretchable member  46  to form a side waist region. As described previously, energy from the preferred bonding process creates a hole in the stretchable member  46  and allows for the topsheet material  16  and the backsheet material  10  to bond therethrough. This also creates a vent at the bond site through which air may pass.  
     [0081] After the bonding process, the resulting composite web  100   b  may be held under vacuum and passed through a die cut station wherein the leg openings are cut out from each of the lateral sections and the corresponding section of the backsheet. Then, the continuous composite web structure  100   b  is cut at a knife station to form individual web structures  10   a . Each web structure  10   a  is subsequently folded and then passed through a seam welding station where side edge areas of the ear regions are joined together by any suitable method of bonding, including ultrasonic, thermal or adhesive bonding. The folded and seamed composite web structure which, at this point, constitutes an individual absorbent garment is passed through a side panel tuck station where the side panel of the garment is folded between the front and back side panels before being delivered to a stacker.  
     [0082] For clarity, some subprocesses such as the application of waist elastic members and leg gathers to the web structure  10   a  are not shown or described. It should be understood, however, that the present invention is adapted to incorporating various constructions of these components and suitable methods of applying such constructions onto a composite web structure  10   a.    
     [0083] It should be noted that the web structure  10   a  and the components that make up the web structure are positioned in the in-line or machine direction C during the preferred manufacturing process (i.e., wherein the longitudinal axis A is coincidental with the direction of web travel). Applicant believes that positioning the web structure  10   a  in this manner furthers efficiency in the manufacturing process and promotes quality in the final product. In one aspect of the invention, the design of the web structure  10   a  and the garment  10 , particularly the use of the stretchable member  46  instead of elongated elastics threads which are directed laterally across the width of the garment  10 , allows for such an in-line process of manufacturing to be employed.  
     [0084] Although several embodiments of the present invention have been shown or described, alternate embodiments will be apparent to those skilled in the art and are within the scope of the present invention. Therefore, the invention is to be limited only by the claims.