CA2122700A1 - Training pant with a film-backed absorbent and method of making the same - Google Patents
Training pant with a film-backed absorbent and method of making the sameInfo
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- CA2122700A1 CA2122700A1 CA 2122700 CA2122700A CA2122700A1 CA 2122700 A1 CA2122700 A1 CA 2122700A1 CA 2122700 CA2122700 CA 2122700 CA 2122700 A CA2122700 A CA 2122700A CA 2122700 A1 CA2122700 A1 CA 2122700A1
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- absorbent
- liquid impermeable
- pant
- impermeable layer
- pair
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Abstract
A child's training pant includes a backsheet that forms a pant body having a waist opening and a pair of leg openings; a film-backed absorbent structure in the interior of the pant body and which includes an absorbent material deposited on a liquid impermeable layer; and elasticized liquid impermeable side flaps associated with the absorbent structure.
Description
- ~1 2 2 ~ O
PATENT
TRAINING PANT WITH A FILM-BACKED ABSORBENT
AND METHOD OF MAKING THE SAME
Backqround of the Invention This invention pertains to disposable absorbent articles, and more particularly to a child's disposable absorbent training pant exhibiting improved waste containment performance.
Various disposable absorbent articles exist today for absorbing waste material of infants and small children. One of these is a disposable diaper that is fitted on the baby by the mother or caretaker.
Because an adult is doing the fitting, the diaper, in most cases, will be properly fitted on the baby. This is an advantage for the designers of diapers since they can design an absorbent crotch that is relatively wide, in relation to the baby's crotch, to improve containment, and still have the assurance that the adult will properly fit the diaper at the crotch of the baby.
In contrast to babies and their diapers, small children in the potty training stage and their training pants represent a different situation. One difference is that these children put on their own training pant, which means that they are the ones that are responsible for ensuring the training pant is properly positioned.
As most parents discover, their children are not as careful in or capable of correctly donning the training pant. This results in the training pant sometimes being worn in a twisted or turned condition at the waist and crotch, or not being pulled up to the waist - ~22 ~
sufflciently to properly fit the absorbent crotch against the wearer.
Sometimes the training pant is even put on backwards.
Another problem is that a training pant having a relatively wide and flat absorbent crotch, such as that found in a typical diaper, further exacerbates the problem of an ill fit. The situation in which a child pulls the pant upwardly in a twisted or turned fashion, or backwards, not only results in improper alignment of the absorbent with the body, but also results in a deformation of the absorbent at the crotch. The deformed absorbent generally will assume the shape of an inverted-U in the crotch. This has an extremely negative impact on the performance of the absorbent. The inverted-U shape tends to cause liquid waste to flow towards either one or both sides of the absorbent, thereby creating pools of waste at the area of least absorbent capacity and highest probability of leaking.
Another difference between the use of a diaper and training pant is that the child wearing a training pant is much more mobile and active than a baby, and this will increase the tendency or chances of a training pant to move out of the correct position.
One attempt to address the above problems was to form the absorbent crotch portion of the training pant more narrow than that of a diaper absorbent crotch portion. This was intended to make the training pant easier to pull up and properly position at the crotch of the wearer. It was also hoped that this would maintain the pant in the proper position during various physical activities of the wearer.
However, this attempt was not entirely successful; it posed an additional problem of having a greater tendency of leaking due to the lesser amount of absorbent material in the crotch area, and increased the possibility of the narrower absorbent crotch portion being off-center relative to the point of urinat;on.
Because of the above, the need continues for a child's disposable training pant that provides the desired absorbent performance, plus the desired fit.
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SummarY of the Invention In one form of the present invention there is provided a disposable absorbent child's training pant including a generally liquid permeable pant body having a front waist section, a back waist section, a crotch section, a waist opening, and a pair of leg openings; an absorbent structure disposed in the pant body at least at the crotch section and including a liquid impermeable layer and an absorbent particulate material directly deposited on the liquid impermeable layer; a pair of longitudinally extending liquid impermeable side flaps associated with the absorbent structure in which each side flap has a flap distal edge; and a flap elastic member elastically associated with each flap distal edge.
In another form of the present invention there is provided a disposable absorbent pant including a pant body having an interior space, a waist opening, a pair of leg openings, and a crotch section;
an absorbent structure disposed in the interior space at the crotch section and including an absorbent material on a liquid impermeable layer; the liquid impermeable layer including a pair of side flaps having distal edges extending laterally beyond the absorbent material; and a flap elastic member elastically associated with each distal edge.
In still another form of the present invention there is provided a disposable absorbent article including an elastic backsheet, a liquid impermeable layer disposed with said elastic backsheet, an absorbent material directly deposited on the liquid impermeable layer, the liquid impermeable layer including a pair of longitudinally extending side flaps having flap distal edges that extend laterally beyond the absorbent material, and a flap elastic member elastically associated with each flap distal edge.
In still yet another form of the present invention there is provided a method of making a disposable absorbent article comprising the steps of providing a liquid impermeable layer of material, directly depositing an absorbent material on the liquid impermeable layer of material, providing a liquid permeable sheet of material, positioning - ,of'~227~Q
the liquid impermeable layer of material and the liquid permeable sheet of material together with the absorbent material therebetween, extending distal edges of the liquid impermeable layer laterally beyond the absorbent material, and elastically associating an elastic member in each of the distal edges of the liquid impermeable layer.
In a further form of the present invention there is provided a method of making a disposable absorbent article comprising the steps of providing a backsheet having longitudinal edges; positioning an absorbent structure on the backsheet, the absorbent structure comprising an absorbent material on a liquid impermeable layer;
extending distal edges of the liquid impermeable layer laterally beyond the absorbent material; elastically associating an elastic member in each of the distal edges of the liquid impermeable layer;
and bonding portions of the longitudinal edges of the backsheet together to form a pant body having a waist opening and a pair of leg openings.
Brief Description of the Drawings The above-mentioned and other features of the present invention and the manner of attaining them will become more apparent, and the invention itself will be better understood by reference to the following description of the invention taken in conjunction with the accompanying drawings, wherein:
Fig. 1 illustrates a front elevational view of a training pant incorporating the principles of the present invention;
Fig. 2 illustrates a partially fragmented, elevational view in cross section of one form of the present invention;
Fig. 3 illustrates a partially fragmented, elevational view in cross section of another form of the present invention;
Fig. 4 illustrates a partially fragmented, elevational view in cross section of still another form of the present invention;
Fig.-5 illustrates a partially fragmented, elevational, exploded end view of the invention illustrated in Fig. 4 with a waist elastic and in which the elements are in a stretched flat condition;
Fig. 6 illustrates a partially fragmented, elevational, exploded end view of the invention illustrated in Fig. 2 with a waist elastic and in which the elements are in a stretched flat condition; and Fig. 7 illustrates a top elevational view of the form in Fig. 2 in a partially disassembled, stretched flat training pant.
Definitions Within the context of this specification, each term or phrase below will include the following meaning or meanings:
(a) "Member" when used in the singular can have the dual meaning of a single element or a plurality of elements.
(b) "Disposed" and variations or uses thereof are intended to mean that one element can be integral with another element, or that one element can be a separate structure joined to or connected to or placed with or placed near another element.
(c) "Associated with" in reference to two or more elements means that the elements can be attached or placed together in any suitable manner that allows them to perform the intended or described function, while not completely inhibiting the properties of the individual elements.
(d) "Elastically associated" with reference to the attachment of an elastic member to another element means that the elastic member when attached to or placed with the element gives that element elastic properties. The attaching or placing can be either directly, such as attaching or placing the member directly with the element, or can be indirectly by means of another member or element between the first member and the first element.
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(e) "Disposable" includes being disposed of after use, and not intended to be washed and reused.
(f) "Elasticity", "elasticized", "elastic", or variations thereof include that property of a material by virtue of which it tends to recover its original size and shape after removal of a force causing a deformation.
(g) "Particles" and "particulates" when used in reference to an absorbent material means that the absorbent material can have the form of individual members, such as fibers, that can be loosely formed into a shaped structure, or compressed into a shaped form. The particles or particulates can have any geometric or non-geometric form, such as cylindrical, spherical, flake-like, flat surface, roughened surface, sheets, ribbons, or the like.
(h) "Stretch-bonded laminate", "SBL", and variations thereof mean at least a two-layered composite in which one layer is a gatherable layer and the other layer is an elastic layer. The layers are joined together when the elastic layer is in a stretched condition so that, upon relaxing the layers, the gatherable layer is gathered and the elastic layer is relaxed, non-gathered.
(i) "Three-dimensional" refers to a finished garment similar to shorts or pants in that they have leg openings and a waist opening that are continuous, i.e., are bounded by the material of which they are made. This type of garment can be opened and laid flat only by destructively tearing it. This type of garment may or may not have manually tearable seams.
These terms may be further defined with additional language in the remaining portion of the specification.
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Detailed DescriDtion Referring to Fig. 1, there is illustrated a training pant 10 incorporating the principles of the present invention. Training pant 10 comprises a pant body 12 having a waist opening 14, leg openings 16, and an interior space 18, for fitting training pant 10 on the body of a wearer. Pant body 12 is formed from a backsheet 20 of material, which desirably is liquid permeable and elastic. One material of which backsheet 20 can be made is a liquid permeable nonwoven web having a basis weight of about 27 grams per square meter (gsm), and which can be formed from spunbond bicomponent fibers or by carding bicomponent fibers. Suitable bicomponent fibers are a wettable, polyethylene/polypropylene bicomponent fiber available from CHISSO Corporation, PP Fiber Division, 6-32, Nakanoshima 3, Kita-Ku, Osaka, Japan. The polypropylene forms the core and the polyethylene forms the sheath of the composite fiber.
Backsheet 20 can be made of other suitable liquid permeable materials. One example is a liquid permeable spunbond polypropylene nonwoven web having a basis weight of about 27 gsm.
Another example of a backsheet 20 includes two layers of a spunbond polypropylene nonwoven web, each web having a basis weight of about 27 gsm, with multiple strands of Lycra~ 940 decitex adhered under a selected tension between the spunbond polypropylene nonwoven webs. A
similar two-layer composite can be made with spunbond or carded bicomponent fibrous webs, such as those described above, in place of the spunbond polypropylene webs.
Still another example is a backsheet 20 made of a stretchable or elastic material that is also liquid permeable, such as a stretch-bonded laminate, or a single layer of elastic material. The stretch-bonded laminate can comprise an inner layer of a prestretched elastic meltblown material sandwiched between and attached to a pair of spunbond polypropylene nonwoven webs, in which the webs have basis weights of about 14 gsm. Suitable elastic materials can be purchased from the Shell Chemical Company, Houston, Texas, under the trademark Kraton~.
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Backsheet 20 also can be made of a liquid impermeable material that may or may not have elastic properties. One example of a non-elastic material is a 0.6 mil polyethylene film obtainable from Edison Plastics Company, South Plainfield, New Jersey.
Backsheet 20 can also be a two-ply laminate, in which the innermost layer can be the above-described liquid impermeable film or any other suitable liquid impermeable layer, and the outermost layer can be the above-described liquid permeable spunbond polypropylene nonwoven web or any other suitable liquid permeable layer. These layers can be joined or attached together in any suitable manner.
Referring primarily to Fig. 7, backsheet 20 is illustrated in a stretched-flat condition with longitudinal centerline 22, and includes front waist section 24 having front edge 26, back waist section 28 having back edge 30, side sections 32 having respective side edges 34, and a crotch section 36. By folding backsheet 20 along a fold line that is generally perpendicular to longitudinal centerline 22, and then bonding the end portions, such as ears 82, of each side section 32 together, pant body 12 is formed having waist opening 14, leg openings 16, and interior space 18 (Fig. 1). One method of forming pant body 12, and a training pant 10, is described in greater detail in U.S. Patent No. 4,940,464, which is assigned to the assignee of the present invention.
Still referring to Fig. 7, the use of the term "longitudinally extendingN or variations thereof with reference to an element means that the element extends in a direction generally parallel to longitudinal centerline 22. The term "laterally" or "transversely"
refers to a direction that is generally perpendicular to longitudinal centerline 22.
Unique features of the present invention are illustrated in various forms with reference to Figs. 2, 3, and 4. These figures typify specific forms of the present invention, but it is understood that ~'1227DO
other forms can be designed and manufactured in accordance with the principles of the present invention.
Fig. 2 illustrates absorbent structure 38 and a layer 40 of material, desirably liquid impermeable, forming a generally longitudinally extending containment pocket 42 adapted to be positioned in the crotch of the wearer. Absorbent structure 38 comprises an absorbent material 44 that can be a mixture of fluff and superabsorbent material (SAM). Absorbent structure 38 can be wrapped in a liquid permeable tissue wrap 46. Suitable superabsorbent materials include inorganic materials such as silica gels or organic compounds such as cross-linked polymers. Examples include polyacrylamides, polyvinyl alcohol, polyacrylates, various grafted starches, and the like. A
specific superabsorbent material is a cross-linked polysodium acrylate, which can be purchased from Hoechst-Celanese, Portsmouth, Virginia. The superabsorbent material and the fluff can be in various geometric or non-geometric particulate forms, such as variously shaped particles, foams, and layers. The absorbent material 44 can be fluff alone, superabsorbent material alone, or a mixture of both or other different types of absorbent materials, and can be formed in various methods well known in the art, such as by air-laying or wet-laying.
The absorbent material 44 of fluff and SAM generally is rectangular in shape, and in one particular shape has a length of about 38 centimeters (cm) and a width of about 11 cm. The fluff and SAM
are suitably present in a ratio of about 10-12 grams fluff to about 10-12 grams superabsorbent material, and have a density within the range of about 0.20 grams per cubic centimeter to about 0.35 grams per cubic centimeter. A more detailed description of this particular absorbent can be found in U.S. Patent Application Serial No. 08/096,654 filed July 22, 1993, which is assigned to the assignee of this application .
The SAM is desirably deposited in the fluff such that more superabsorbent material is concentrated adjacent to or near backsheet ~12~7~
20. The absorbent material 44 can also be zoned, in that a greater amount of fluff and/or SAM can be located in the center of the absorbent structure 38 or toward the front or back of absorbent structure 38. For example, a girl's training pant would generally have more absorbent zoned or concentrated at the longitudinal center of the absorbent structure, while a boy's training pant would have more absorbent zoned or concentrated at a position intermediate the longitudinal center and the front edge of the absorbent structure.
It should also be understood that the fluff and SAM can be mixed in any desirable fashion or concentration, and that the SAM can exist as a discrete layer anywhere within the fluff, or on top of or below the fluff.
Absorbent structure 38 can be a single, integral structure, or can comprise a plurality of individual, separate structures that are operably assembled together. If absorbent structure 38 comprises multiple structures, the structures can be configured as discrete layers or as other non-layered shapes and configurations.
Furthermore, the individual structures can be coextensive or non-coextensive. It is desired that each individual absorbent structure be arranged in operable, intimate contact along at least a portion of its boundary with at least one other adjacent absorbent structure.
Still referring to Fig. 2, absorbent structure 38 includes a longitudinally extending absorbent central portion 48, a pair of longitudinally extending absorbent side portions 50, absorbent front end 49 (Fig. 7), absorbent back end 51 (Fig. 7), and an absorbent crotch portion 52 (Fig. 7). The term "central" means to be intermediate two spaced-apart positions or elements, which in the case of absorbent central portion 48 are the absorbent side portions 50. Absorbent central portion 48 and absorbent side portions 50 can have the same or different absorbent and/or physical characteristics.
For example, absorbent central portion 48 can have a higher, lower, or the same basis weight as one of the absorbent side portions 50, or absorbent central portion 48 can have a higher, lower, or the same density as one of the absorbent side portions 50. Similarly, ~1227~0 absorbent central portion 48 can have a higher, lower, or the same concentration of SAM as one of the absorbent side portions 50. Thus, the present invention contemplates various combinations of basis weights and densities that provide the same or different absorbent capacities between portions 48 and 50.
A unique feature of the present invention is weakened area 54 which extends longitudinally of absorbent structure 38. As illustrated in Fig. 2, there are two weakened areas 54 in absorbent structure 38 where the absorbent side portions 50 are turned or moved upwardly relative to absorbent central portion 48. The term "upwardly" is to be understood with reference to Fig. 2 in which absorbent central portion 48 is illustrated in a relatively flat or horizontal manner.
Thus, with reference to absorbent central portion 48 in Fig. 2, absorbent side portions 50 are turned generally upwardly or vertically. This provides absorbent structure 38 with a shape that improves its performance as an absorbent compared to more narrow absorbents, especially at the wearer's crotch. Weakened areas 54 can be continuous or discontinuous, and are sufficient to allow absorbent side portions 50 to move upwardly relative to absorbent central portion 48, as illustrated in Fig. 2. A weakened area 54 can be provided by various methods. One method is to form absorbent structure 38 with laterally tapering absorbent side portions 50. For example, absorbent central portion 48 can have a generally uniform thickness, while an absorbent side portion 50 can taper in a laterally converging manner away from absorbent central portion 48.
Generally, the tapering will begin at least about 1 centimeter in from the longitudinal edge of an absorbent side portion 76, and preferably about 2 centimeters in from the longitudinal edge of an absorbent side portion 76.
Absorbent structure 38 also can be generally oval-shape, in transverse cross-section, in which absorbent central portion 48 has its greatest thickness along its longitudinal centerline.
Another method of providing weakened areas 54 is to form an absorbent structure 38 which has its greatest thickness along centerline 22 and ~1~2~
along or near both of its longitudinal edges, with a lesser thickness between each longitudinal edge and centerline 22. In transverse cross-section, this would have an undulating appearance.
Weakened area 54 can also be provided by longitudinally cutting absorbent side portions 50 from absorbent central portion 48, and then positioning absorbent side portions 50 in operable, intimate contact with absorbent central portion 48. Weakened area 54 is then represented by the boundary between an absorbent side portion 50 and absorbent central portion 48, and is the longitudinally extending area at which an absorbent side portion 50 can be moved upwardly relative to absorbent central portion 48. Rather than totally, separately cutting an absorbent side portion 50 from absorbent central portion 48, a slit or score line (Fig. 6) can be run along absorbent structure 38 to provide a weakened area 54 at which that particular absorbent side portion 50 can move upwardly relative to absorbent central portion 48. By slit or score is meant that absorbent structure 38 is cut in a fashion that does not totally separate an absorbent side portion 50 from absorbent central portion 48.
There also can be only one weakened area 54 along centerline 22 (Fig. 7) so that absorbent structure 38 can form a generally V-shape.
In this form, there is no absorbent central portion 48 between absorbent side portions 50.
As described, the present invention thus contemplates the term "weakened area" to include any design, mechanism, or method that permits an absorbent side portion 50 to be movable upwardly relative to absorbent central portion 48. Additionally, it should be understood that absorbent structure 38 can be designed or comprised of materials that permit it to be easily flexed or shaped without the necessity of a weakened area 54.
In order to enhance the absorbent performance of the absorbent structure 38, a surge layer 55 is associated with absorbent structure 38, and specifically is positioned on top of absorbent central ~1~27~0 portion 48, as illustrated in Fig. 2. Surge layer 55 may be placed on top of permeable layer 56, as illustrated in Fig. 2, or may be placed between permeable layer 56 and absorbent structure 38. The position of surge layer 55 in some respects depends upon the material of which it is made, as well as layer 56 and absorbent structure 38.
Surge layer 55 may or may not extend the total width, i.e., transverse dimension, of absorbent structure 38. Surge layer 55 can be a through-air, bonded carded web, a spunbond bicomponent nonwoven web, a web of cross-linked cellulosic fibers, or the like. Surge layer 55 can have an overall basis weight of about 50 gsm and an overall density of about 0.03 grams per cubic centimeter. Surge layer 55 can be a two-layered composite in which the first layer, which is the layer that will be adjacent the wearer's body, is a 15 gsm layer composed of 100 percent polyethylene/polyester, sheath-core bicomponent fibers having a fiber denier of about 1.8 to about 3denier (d). The second layer, which is the outermost layer in the composite, is a 35 gsm layer composed of a mixture of bicomponent fibers and single component fibers. The bicomponent fibers form about 40 percent by weight of the outermost layer. More particularly, 35 percent by weight of the outermost layer is composed of about 1.8 d polyethylene/polyester sheath-core fibers with flat crimp, and about 5 percent by weight of the outermost layer is composed of 2 d polyethylene/polypropylene sheath-core fibers with helical crimp. The single component fibers form about 60 percent by weight of the outermost layer, and are about 6 d polyester fibers configured with a flat crimp. The polyester fibers are not hollow core fibers. Surge layer 55 is permeable to liquid when compressed under loads experienced during the wear of the absorbent article.
Descriptions of other suitable materials of which surge layer 55 can be made are described in U.S. Patent Application Serial No.
08/096,654 . Suitable bicomponent fibers are available from Chisso, Osaka, Japan.
Continuing to refer to Fig. 2, absorbent structure 38 and layer 40 are partially enveloped by permeable layer 56. Layer 56 can be rendered permeable in numerous ways. For example, permeable layer 56 can be made of the same material and in the same manner as a liquid ~12~)700 permeable backsheet 20. Layer 56 also can be a film of liquid impermeable material rendered permeable by a multiplicity of apertures therethrough. Layer 56 further can be totally or partially elastic, for example, by making layer 56 of an elastomeric material.
The direction of stretch can be in the longitudinal direction, transverse direction, or multiple directions. Generally, the direction of stretch is determined during the manufacture of the elastomeric material, and is related to the molecular orientation of the manufactured elastomeric material. Suitable elastic materials are described in the aforementioned u.s. Patent Pat.
No. 4,940,464. One desired permeable layer 56 is a spunbond polypropylene web having a basis weight of about 25 gsm.
Layer 40 includes a pair of side flaps 58 that have respective flap distal edges 60. Each flap distal edge 60 has a flap elastic member 62 elastically associated therewith. Each flap elastic member 62 is desirably three strands of Lycra~ 940 decitex that are attached at their ends at an elongation of about 250%. Each individual strand in a respective elastic member 62 is spaced from another adjacent elastic strand by about 3 mm. These elastic strands can be obtained form E. I. DuPont De Nemours Company, Wilmington, Delaware. Each elastic member 62 can also be one or more strands of the above described elastic, or can be made of other suitable elastic materials such as natural rubber, synthetic rubber, or thermoplastic elastomeric polymers. These elastic materials may also be heat-shrinkable or heat-elasticizable, and can also be single or multiple ribbons of elastic material. As illustrated in Fig. 2, each uppermost single elastic member 62 may be about level with or about at the same height as a corresponding absorbent side portion 50.
Also, flap elastic members 62 are generally positioned between layer 40 and layer 56. If desired, each flap elastic member 62 can be located at a greater height than or above a respective flap distal edge 60 and the outermost edge of an absorbent side portion 50, and in this case would be sandwiched by layer 56.
Layer 40 is continuous in the transverse or lateral direction in that it extends below or underneath absorbent structure 38. In Fig. 7, ~l~27&~
layer 40 extends longitudinally beyond absorbent front end 49 and absorbent back end 51, and the extensions of layer 40 are folded over and attached to absorbent structure 38 to form waist dams 41.
With reference to Fig. 3, another form of the present invention is illustrated in which absorbent structure 38 does not include tissue wrap 46. One of the unique features of the present invention is that it provides for direct depositing of absorbent material 44 on layer 40, which desirably is liquid impermeable. By "direct deposition", "directly depositing", or variations thereof, is meant that the fluff and/or SAM particles, or other absorbent material or materials, are deposited, formed, laid, or the like, directly on liquid impermeable layer 40 and are not encased within tissue wrap 46 or any similar porous structure that is disposed between absorbent material 44 and liquid impermeable layer 40. Absorbent material 44 may be directly deposited in any suitable manner, such as by air-laying or wet-laying. In most cases, it is desired that absorbent material 44 be provided with some type of mechanism for ensuring that it maintains its integrity and shape when being deposited on layer 40 and thereafter during the manufacturing process and use by the consumer.
If an air-laying process is used, synthetic fibers may be intermixed with the fluff and/or SAM by means of a meltblowing process so that the tacky synthetic fibers provide sufficient adherence to and between the fluff and SAM to ensure their integrity in the desired shape and position on layer 40. Water may also be sprayed or otherwise delivered to the fluff and/or SAM during the air-laying process in order to provide hydrogen bonding to ensure the integrity of the absorbent material. The absorbent material 44 can also be mechanically treated in order to maintain the integrity of the desired shape, and such mechanical treating includes passing the absorbent structure through a pair of nip rolls in order to compress the material together.
Absorbent material 44 can comprise, in one specific embodiment, an air-laid nonwoven web comprising about 80 percent by weight fibrous superabsorbent material and about 20 percent by weight polymeric binder fibers. The fibrous superabsorbent materials have a denier of ~227~
about 9 d and a length of about 12 millimeters. Suitable fibrous superabsorbent materials are available from Technical Absorbents Ltd.
of the United Kingdom under the trade-mark OASIS. The polymeric binder fibers have a denier of about 3 d and a length of about 6 millimeters. Such binder fibers may be bicomponent fibers comprising about 50 percent by weight polyethylene and about 50 percent by weight polypropylene in a concentric sheath-core configuration. Suitable bicomponent binder fibers are available from Danaklon a/s of Varde, Denmark, under the trade-mark Danaklon AL
Thermal-C. Such a composite web may be oven fused after air-laying for five minutes at a temperature of about 150 degrees Celsius. The composite web may have a basis weight of about 200 grams per square meter.
Other methods are known or may become known, as well as other absorbent materials, that permit directly depositing absorbent material 44 on layer 40. Absorbent material 44 is attached to layer 40 by the same mechanism that maintains the integrity of absorbent material 44, or may be attached by use of any suitable adhesive or by other types of bonding, such as thermal, ultrasonic, or the like.
Absorbent structure 38 may or may not include weakened areas 54 that assist in forming absorbent structure 38 in a generally U-like shape.
Referring now to Fig. 4, absorbent structure 38 does not include absorbent side portions 50 formed by weakened areas 54, as is the case in Figs. 2-3. In Fig. 4, each side flap 58 includes a portion of layer 40 sandwiched between permeable layer 56. Similar to the absorbent structure in Fig. 3, the absorbent structure 38 of Fig. 4 is also formed by directly depositing absorbent material 44 on layer 40. Absorbent structure 38 and layer 40 are then partially enveloped by permeable layer 56 with surge layer 55 positioned on top of absorbent structure 38.
Referring to Fig. 5, there is illustrated a partially fragmented, exploded, elevational view of the invention illustrated in Fig. 4 with the side flaps 58 in a flat or horizontal condition. In one method of the present invention, a continuously moving backsheet 20 ~1 22 7~ ~
has waist elastic adhesive 64 intermittently applied in a lateral direction for adhering a waist elastic 66 thereto. Waist elastic 66 is preferably a heat-shrinkable elastic that is activated during the manufacturing process, and generally at the end of the process in order to provide elasticity at the front waist section 24 and back waist section 28 (Fig. 7). Waist elastic adhesive 64, as well as the following adhesives to be described, can be made of any suitable adhesive and applied in any suitable pattern. Such adhesives can be obtained from Findley Adhesives, Inc., Wauwatosa, Wisconsin. The adhesives can be applied in any manner such as spraying, slot-coat extrusion, printing, or the like. The adhesives can be sprayed in any desired configuration or design such as continuous or discontinuous beads, discontinuous or continuous swirls, melt-blown, pattern, spray pattern, or the like. Construction adhesive 68 is then applied to continuously moving backsheet 20. Separately, continuously moving liquid impermeable layer 40 has absorbent material 44 directly deposited thereon. Flap elastic members 62 are applied in a stretched condition to side flaps 58 of layer 40 and are attached at their ends to side flaps 58 by flap elastic adhesive 72.
Separately, permeable layer 56 has adhesive 70 applied thereto, and is then brought together with layer 40, absorbent material 44, and flap elastic members 62, and is folded therearound. This joined structure of layer 40, absorbent material 44, flap elastic members 62, and layer 56 is positioned on construction adhesive 68. Surge adhesive 74 is applied on permeable layer 56 for attaching surge layer 55 thereto. This describes one method in which the identified elements are brought together in one form of the present invention.
Other methods or steps are possible, such as joining the elements in a different sequence, joining the elements in a different positional relationship, or the like. The present invention further contemplates that the attachment of elements can be accomplished other than by adhesives, such as by ultrasonic bonding, heat bonding, fiber entanglement, and the like.
Referring now to Fig. 6, a second method of the present invention is illustrated in which tissue wrap 46 has been placed around absorbent material 44, and weakened areas 54 have been provided to define .~1 22 7~ tJ3 absorbent central portion 48 and absorbent side portions 50. After absorbent structure 38 has been formed, it is then positioned on layer 40 and attached thereto by structure adhesive 76. Backsheet 20, waist elastics 66, and surge layer 55 can then be joined together with layer 40, layer 56, and absorbent structure 38 in any suitable manner.
Turning now to Fig. 7, the construction of an individual training pant 10 will be explained in steps that occur subsequently to those described with reference to Fig. 5. If desired, portions of backsheet 20 can be cut, by any suitable device, in order to form leg cut-outs 78 that will later form leg openings 16. Leg elastics 80 are then applied in a curved fashion as illustrated in Fig. 7.
Alternatively, leg elastics 80 can be applied in a straight or linear fashion parallel to longitudinal centerline 22, as is well known in the art. In forming leg-cutouts 78, four ears 82 are formed and will become portions of side sections 32 in the finished training pant 10.
Each ear 82 has an elastic area 84 elastically associated therewith.
Elastic areas 84 can be formed by multiple strands of elastic material arranged in any orientation, such as parallel, intersecting, or both. Elastic areas 84 can be a film or laminate of elastomeric material. Various materials and examples of providing elasticity at ears 82 are described in U.S. Patent No. 4,940,464 and U.S. Patent Application Serial No. 08/043,132 filed on March 25, 1993.
These two references also disclose materials or methods of incorporating leg elastic members 80, as well as waist elastics 66 in their respective front and back waist sections 24, 28. Backsheet 20 further can be made of a single layer of elastic material, or a layer of elastic material suitably joined with other non-elastic layers, for example, a stretch-bonded laminate. After backsheet 20 has been cut, it is then folded along a fold-line generally perpendicular to longitudinal centerline 22 so that the adjacent pairs of ears 82 can be attached or bonded together to form training pant 10 with waist opening 14 and leg opening 16.
- ~12~70~
While this invention has been described as having a preferred embodiment, it will be understood that it is capable of further modifications. This application is therefore intended to cover any variations, equivalents, uses, or adaptations of the invention following the general principles thereof, and including such departures from the present disclosure as come or may come within known or customary practice in the art to which this invention pertains and falls within the limits of the appended claims.
PATENT
TRAINING PANT WITH A FILM-BACKED ABSORBENT
AND METHOD OF MAKING THE SAME
Backqround of the Invention This invention pertains to disposable absorbent articles, and more particularly to a child's disposable absorbent training pant exhibiting improved waste containment performance.
Various disposable absorbent articles exist today for absorbing waste material of infants and small children. One of these is a disposable diaper that is fitted on the baby by the mother or caretaker.
Because an adult is doing the fitting, the diaper, in most cases, will be properly fitted on the baby. This is an advantage for the designers of diapers since they can design an absorbent crotch that is relatively wide, in relation to the baby's crotch, to improve containment, and still have the assurance that the adult will properly fit the diaper at the crotch of the baby.
In contrast to babies and their diapers, small children in the potty training stage and their training pants represent a different situation. One difference is that these children put on their own training pant, which means that they are the ones that are responsible for ensuring the training pant is properly positioned.
As most parents discover, their children are not as careful in or capable of correctly donning the training pant. This results in the training pant sometimes being worn in a twisted or turned condition at the waist and crotch, or not being pulled up to the waist - ~22 ~
sufflciently to properly fit the absorbent crotch against the wearer.
Sometimes the training pant is even put on backwards.
Another problem is that a training pant having a relatively wide and flat absorbent crotch, such as that found in a typical diaper, further exacerbates the problem of an ill fit. The situation in which a child pulls the pant upwardly in a twisted or turned fashion, or backwards, not only results in improper alignment of the absorbent with the body, but also results in a deformation of the absorbent at the crotch. The deformed absorbent generally will assume the shape of an inverted-U in the crotch. This has an extremely negative impact on the performance of the absorbent. The inverted-U shape tends to cause liquid waste to flow towards either one or both sides of the absorbent, thereby creating pools of waste at the area of least absorbent capacity and highest probability of leaking.
Another difference between the use of a diaper and training pant is that the child wearing a training pant is much more mobile and active than a baby, and this will increase the tendency or chances of a training pant to move out of the correct position.
One attempt to address the above problems was to form the absorbent crotch portion of the training pant more narrow than that of a diaper absorbent crotch portion. This was intended to make the training pant easier to pull up and properly position at the crotch of the wearer. It was also hoped that this would maintain the pant in the proper position during various physical activities of the wearer.
However, this attempt was not entirely successful; it posed an additional problem of having a greater tendency of leaking due to the lesser amount of absorbent material in the crotch area, and increased the possibility of the narrower absorbent crotch portion being off-center relative to the point of urinat;on.
Because of the above, the need continues for a child's disposable training pant that provides the desired absorbent performance, plus the desired fit.
~122 79 J
SummarY of the Invention In one form of the present invention there is provided a disposable absorbent child's training pant including a generally liquid permeable pant body having a front waist section, a back waist section, a crotch section, a waist opening, and a pair of leg openings; an absorbent structure disposed in the pant body at least at the crotch section and including a liquid impermeable layer and an absorbent particulate material directly deposited on the liquid impermeable layer; a pair of longitudinally extending liquid impermeable side flaps associated with the absorbent structure in which each side flap has a flap distal edge; and a flap elastic member elastically associated with each flap distal edge.
In another form of the present invention there is provided a disposable absorbent pant including a pant body having an interior space, a waist opening, a pair of leg openings, and a crotch section;
an absorbent structure disposed in the interior space at the crotch section and including an absorbent material on a liquid impermeable layer; the liquid impermeable layer including a pair of side flaps having distal edges extending laterally beyond the absorbent material; and a flap elastic member elastically associated with each distal edge.
In still another form of the present invention there is provided a disposable absorbent article including an elastic backsheet, a liquid impermeable layer disposed with said elastic backsheet, an absorbent material directly deposited on the liquid impermeable layer, the liquid impermeable layer including a pair of longitudinally extending side flaps having flap distal edges that extend laterally beyond the absorbent material, and a flap elastic member elastically associated with each flap distal edge.
In still yet another form of the present invention there is provided a method of making a disposable absorbent article comprising the steps of providing a liquid impermeable layer of material, directly depositing an absorbent material on the liquid impermeable layer of material, providing a liquid permeable sheet of material, positioning - ,of'~227~Q
the liquid impermeable layer of material and the liquid permeable sheet of material together with the absorbent material therebetween, extending distal edges of the liquid impermeable layer laterally beyond the absorbent material, and elastically associating an elastic member in each of the distal edges of the liquid impermeable layer.
In a further form of the present invention there is provided a method of making a disposable absorbent article comprising the steps of providing a backsheet having longitudinal edges; positioning an absorbent structure on the backsheet, the absorbent structure comprising an absorbent material on a liquid impermeable layer;
extending distal edges of the liquid impermeable layer laterally beyond the absorbent material; elastically associating an elastic member in each of the distal edges of the liquid impermeable layer;
and bonding portions of the longitudinal edges of the backsheet together to form a pant body having a waist opening and a pair of leg openings.
Brief Description of the Drawings The above-mentioned and other features of the present invention and the manner of attaining them will become more apparent, and the invention itself will be better understood by reference to the following description of the invention taken in conjunction with the accompanying drawings, wherein:
Fig. 1 illustrates a front elevational view of a training pant incorporating the principles of the present invention;
Fig. 2 illustrates a partially fragmented, elevational view in cross section of one form of the present invention;
Fig. 3 illustrates a partially fragmented, elevational view in cross section of another form of the present invention;
Fig. 4 illustrates a partially fragmented, elevational view in cross section of still another form of the present invention;
Fig.-5 illustrates a partially fragmented, elevational, exploded end view of the invention illustrated in Fig. 4 with a waist elastic and in which the elements are in a stretched flat condition;
Fig. 6 illustrates a partially fragmented, elevational, exploded end view of the invention illustrated in Fig. 2 with a waist elastic and in which the elements are in a stretched flat condition; and Fig. 7 illustrates a top elevational view of the form in Fig. 2 in a partially disassembled, stretched flat training pant.
Definitions Within the context of this specification, each term or phrase below will include the following meaning or meanings:
(a) "Member" when used in the singular can have the dual meaning of a single element or a plurality of elements.
(b) "Disposed" and variations or uses thereof are intended to mean that one element can be integral with another element, or that one element can be a separate structure joined to or connected to or placed with or placed near another element.
(c) "Associated with" in reference to two or more elements means that the elements can be attached or placed together in any suitable manner that allows them to perform the intended or described function, while not completely inhibiting the properties of the individual elements.
(d) "Elastically associated" with reference to the attachment of an elastic member to another element means that the elastic member when attached to or placed with the element gives that element elastic properties. The attaching or placing can be either directly, such as attaching or placing the member directly with the element, or can be indirectly by means of another member or element between the first member and the first element.
- ~1227~D
(e) "Disposable" includes being disposed of after use, and not intended to be washed and reused.
(f) "Elasticity", "elasticized", "elastic", or variations thereof include that property of a material by virtue of which it tends to recover its original size and shape after removal of a force causing a deformation.
(g) "Particles" and "particulates" when used in reference to an absorbent material means that the absorbent material can have the form of individual members, such as fibers, that can be loosely formed into a shaped structure, or compressed into a shaped form. The particles or particulates can have any geometric or non-geometric form, such as cylindrical, spherical, flake-like, flat surface, roughened surface, sheets, ribbons, or the like.
(h) "Stretch-bonded laminate", "SBL", and variations thereof mean at least a two-layered composite in which one layer is a gatherable layer and the other layer is an elastic layer. The layers are joined together when the elastic layer is in a stretched condition so that, upon relaxing the layers, the gatherable layer is gathered and the elastic layer is relaxed, non-gathered.
(i) "Three-dimensional" refers to a finished garment similar to shorts or pants in that they have leg openings and a waist opening that are continuous, i.e., are bounded by the material of which they are made. This type of garment can be opened and laid flat only by destructively tearing it. This type of garment may or may not have manually tearable seams.
These terms may be further defined with additional language in the remaining portion of the specification.
~1227~
Detailed DescriDtion Referring to Fig. 1, there is illustrated a training pant 10 incorporating the principles of the present invention. Training pant 10 comprises a pant body 12 having a waist opening 14, leg openings 16, and an interior space 18, for fitting training pant 10 on the body of a wearer. Pant body 12 is formed from a backsheet 20 of material, which desirably is liquid permeable and elastic. One material of which backsheet 20 can be made is a liquid permeable nonwoven web having a basis weight of about 27 grams per square meter (gsm), and which can be formed from spunbond bicomponent fibers or by carding bicomponent fibers. Suitable bicomponent fibers are a wettable, polyethylene/polypropylene bicomponent fiber available from CHISSO Corporation, PP Fiber Division, 6-32, Nakanoshima 3, Kita-Ku, Osaka, Japan. The polypropylene forms the core and the polyethylene forms the sheath of the composite fiber.
Backsheet 20 can be made of other suitable liquid permeable materials. One example is a liquid permeable spunbond polypropylene nonwoven web having a basis weight of about 27 gsm.
Another example of a backsheet 20 includes two layers of a spunbond polypropylene nonwoven web, each web having a basis weight of about 27 gsm, with multiple strands of Lycra~ 940 decitex adhered under a selected tension between the spunbond polypropylene nonwoven webs. A
similar two-layer composite can be made with spunbond or carded bicomponent fibrous webs, such as those described above, in place of the spunbond polypropylene webs.
Still another example is a backsheet 20 made of a stretchable or elastic material that is also liquid permeable, such as a stretch-bonded laminate, or a single layer of elastic material. The stretch-bonded laminate can comprise an inner layer of a prestretched elastic meltblown material sandwiched between and attached to a pair of spunbond polypropylene nonwoven webs, in which the webs have basis weights of about 14 gsm. Suitable elastic materials can be purchased from the Shell Chemical Company, Houston, Texas, under the trademark Kraton~.
~I~2 7~ ~
Backsheet 20 also can be made of a liquid impermeable material that may or may not have elastic properties. One example of a non-elastic material is a 0.6 mil polyethylene film obtainable from Edison Plastics Company, South Plainfield, New Jersey.
Backsheet 20 can also be a two-ply laminate, in which the innermost layer can be the above-described liquid impermeable film or any other suitable liquid impermeable layer, and the outermost layer can be the above-described liquid permeable spunbond polypropylene nonwoven web or any other suitable liquid permeable layer. These layers can be joined or attached together in any suitable manner.
Referring primarily to Fig. 7, backsheet 20 is illustrated in a stretched-flat condition with longitudinal centerline 22, and includes front waist section 24 having front edge 26, back waist section 28 having back edge 30, side sections 32 having respective side edges 34, and a crotch section 36. By folding backsheet 20 along a fold line that is generally perpendicular to longitudinal centerline 22, and then bonding the end portions, such as ears 82, of each side section 32 together, pant body 12 is formed having waist opening 14, leg openings 16, and interior space 18 (Fig. 1). One method of forming pant body 12, and a training pant 10, is described in greater detail in U.S. Patent No. 4,940,464, which is assigned to the assignee of the present invention.
Still referring to Fig. 7, the use of the term "longitudinally extendingN or variations thereof with reference to an element means that the element extends in a direction generally parallel to longitudinal centerline 22. The term "laterally" or "transversely"
refers to a direction that is generally perpendicular to longitudinal centerline 22.
Unique features of the present invention are illustrated in various forms with reference to Figs. 2, 3, and 4. These figures typify specific forms of the present invention, but it is understood that ~'1227DO
other forms can be designed and manufactured in accordance with the principles of the present invention.
Fig. 2 illustrates absorbent structure 38 and a layer 40 of material, desirably liquid impermeable, forming a generally longitudinally extending containment pocket 42 adapted to be positioned in the crotch of the wearer. Absorbent structure 38 comprises an absorbent material 44 that can be a mixture of fluff and superabsorbent material (SAM). Absorbent structure 38 can be wrapped in a liquid permeable tissue wrap 46. Suitable superabsorbent materials include inorganic materials such as silica gels or organic compounds such as cross-linked polymers. Examples include polyacrylamides, polyvinyl alcohol, polyacrylates, various grafted starches, and the like. A
specific superabsorbent material is a cross-linked polysodium acrylate, which can be purchased from Hoechst-Celanese, Portsmouth, Virginia. The superabsorbent material and the fluff can be in various geometric or non-geometric particulate forms, such as variously shaped particles, foams, and layers. The absorbent material 44 can be fluff alone, superabsorbent material alone, or a mixture of both or other different types of absorbent materials, and can be formed in various methods well known in the art, such as by air-laying or wet-laying.
The absorbent material 44 of fluff and SAM generally is rectangular in shape, and in one particular shape has a length of about 38 centimeters (cm) and a width of about 11 cm. The fluff and SAM
are suitably present in a ratio of about 10-12 grams fluff to about 10-12 grams superabsorbent material, and have a density within the range of about 0.20 grams per cubic centimeter to about 0.35 grams per cubic centimeter. A more detailed description of this particular absorbent can be found in U.S. Patent Application Serial No. 08/096,654 filed July 22, 1993, which is assigned to the assignee of this application .
The SAM is desirably deposited in the fluff such that more superabsorbent material is concentrated adjacent to or near backsheet ~12~7~
20. The absorbent material 44 can also be zoned, in that a greater amount of fluff and/or SAM can be located in the center of the absorbent structure 38 or toward the front or back of absorbent structure 38. For example, a girl's training pant would generally have more absorbent zoned or concentrated at the longitudinal center of the absorbent structure, while a boy's training pant would have more absorbent zoned or concentrated at a position intermediate the longitudinal center and the front edge of the absorbent structure.
It should also be understood that the fluff and SAM can be mixed in any desirable fashion or concentration, and that the SAM can exist as a discrete layer anywhere within the fluff, or on top of or below the fluff.
Absorbent structure 38 can be a single, integral structure, or can comprise a plurality of individual, separate structures that are operably assembled together. If absorbent structure 38 comprises multiple structures, the structures can be configured as discrete layers or as other non-layered shapes and configurations.
Furthermore, the individual structures can be coextensive or non-coextensive. It is desired that each individual absorbent structure be arranged in operable, intimate contact along at least a portion of its boundary with at least one other adjacent absorbent structure.
Still referring to Fig. 2, absorbent structure 38 includes a longitudinally extending absorbent central portion 48, a pair of longitudinally extending absorbent side portions 50, absorbent front end 49 (Fig. 7), absorbent back end 51 (Fig. 7), and an absorbent crotch portion 52 (Fig. 7). The term "central" means to be intermediate two spaced-apart positions or elements, which in the case of absorbent central portion 48 are the absorbent side portions 50. Absorbent central portion 48 and absorbent side portions 50 can have the same or different absorbent and/or physical characteristics.
For example, absorbent central portion 48 can have a higher, lower, or the same basis weight as one of the absorbent side portions 50, or absorbent central portion 48 can have a higher, lower, or the same density as one of the absorbent side portions 50. Similarly, ~1227~0 absorbent central portion 48 can have a higher, lower, or the same concentration of SAM as one of the absorbent side portions 50. Thus, the present invention contemplates various combinations of basis weights and densities that provide the same or different absorbent capacities between portions 48 and 50.
A unique feature of the present invention is weakened area 54 which extends longitudinally of absorbent structure 38. As illustrated in Fig. 2, there are two weakened areas 54 in absorbent structure 38 where the absorbent side portions 50 are turned or moved upwardly relative to absorbent central portion 48. The term "upwardly" is to be understood with reference to Fig. 2 in which absorbent central portion 48 is illustrated in a relatively flat or horizontal manner.
Thus, with reference to absorbent central portion 48 in Fig. 2, absorbent side portions 50 are turned generally upwardly or vertically. This provides absorbent structure 38 with a shape that improves its performance as an absorbent compared to more narrow absorbents, especially at the wearer's crotch. Weakened areas 54 can be continuous or discontinuous, and are sufficient to allow absorbent side portions 50 to move upwardly relative to absorbent central portion 48, as illustrated in Fig. 2. A weakened area 54 can be provided by various methods. One method is to form absorbent structure 38 with laterally tapering absorbent side portions 50. For example, absorbent central portion 48 can have a generally uniform thickness, while an absorbent side portion 50 can taper in a laterally converging manner away from absorbent central portion 48.
Generally, the tapering will begin at least about 1 centimeter in from the longitudinal edge of an absorbent side portion 76, and preferably about 2 centimeters in from the longitudinal edge of an absorbent side portion 76.
Absorbent structure 38 also can be generally oval-shape, in transverse cross-section, in which absorbent central portion 48 has its greatest thickness along its longitudinal centerline.
Another method of providing weakened areas 54 is to form an absorbent structure 38 which has its greatest thickness along centerline 22 and ~1~2~
along or near both of its longitudinal edges, with a lesser thickness between each longitudinal edge and centerline 22. In transverse cross-section, this would have an undulating appearance.
Weakened area 54 can also be provided by longitudinally cutting absorbent side portions 50 from absorbent central portion 48, and then positioning absorbent side portions 50 in operable, intimate contact with absorbent central portion 48. Weakened area 54 is then represented by the boundary between an absorbent side portion 50 and absorbent central portion 48, and is the longitudinally extending area at which an absorbent side portion 50 can be moved upwardly relative to absorbent central portion 48. Rather than totally, separately cutting an absorbent side portion 50 from absorbent central portion 48, a slit or score line (Fig. 6) can be run along absorbent structure 38 to provide a weakened area 54 at which that particular absorbent side portion 50 can move upwardly relative to absorbent central portion 48. By slit or score is meant that absorbent structure 38 is cut in a fashion that does not totally separate an absorbent side portion 50 from absorbent central portion 48.
There also can be only one weakened area 54 along centerline 22 (Fig. 7) so that absorbent structure 38 can form a generally V-shape.
In this form, there is no absorbent central portion 48 between absorbent side portions 50.
As described, the present invention thus contemplates the term "weakened area" to include any design, mechanism, or method that permits an absorbent side portion 50 to be movable upwardly relative to absorbent central portion 48. Additionally, it should be understood that absorbent structure 38 can be designed or comprised of materials that permit it to be easily flexed or shaped without the necessity of a weakened area 54.
In order to enhance the absorbent performance of the absorbent structure 38, a surge layer 55 is associated with absorbent structure 38, and specifically is positioned on top of absorbent central ~1~27~0 portion 48, as illustrated in Fig. 2. Surge layer 55 may be placed on top of permeable layer 56, as illustrated in Fig. 2, or may be placed between permeable layer 56 and absorbent structure 38. The position of surge layer 55 in some respects depends upon the material of which it is made, as well as layer 56 and absorbent structure 38.
Surge layer 55 may or may not extend the total width, i.e., transverse dimension, of absorbent structure 38. Surge layer 55 can be a through-air, bonded carded web, a spunbond bicomponent nonwoven web, a web of cross-linked cellulosic fibers, or the like. Surge layer 55 can have an overall basis weight of about 50 gsm and an overall density of about 0.03 grams per cubic centimeter. Surge layer 55 can be a two-layered composite in which the first layer, which is the layer that will be adjacent the wearer's body, is a 15 gsm layer composed of 100 percent polyethylene/polyester, sheath-core bicomponent fibers having a fiber denier of about 1.8 to about 3denier (d). The second layer, which is the outermost layer in the composite, is a 35 gsm layer composed of a mixture of bicomponent fibers and single component fibers. The bicomponent fibers form about 40 percent by weight of the outermost layer. More particularly, 35 percent by weight of the outermost layer is composed of about 1.8 d polyethylene/polyester sheath-core fibers with flat crimp, and about 5 percent by weight of the outermost layer is composed of 2 d polyethylene/polypropylene sheath-core fibers with helical crimp. The single component fibers form about 60 percent by weight of the outermost layer, and are about 6 d polyester fibers configured with a flat crimp. The polyester fibers are not hollow core fibers. Surge layer 55 is permeable to liquid when compressed under loads experienced during the wear of the absorbent article.
Descriptions of other suitable materials of which surge layer 55 can be made are described in U.S. Patent Application Serial No.
08/096,654 . Suitable bicomponent fibers are available from Chisso, Osaka, Japan.
Continuing to refer to Fig. 2, absorbent structure 38 and layer 40 are partially enveloped by permeable layer 56. Layer 56 can be rendered permeable in numerous ways. For example, permeable layer 56 can be made of the same material and in the same manner as a liquid ~12~)700 permeable backsheet 20. Layer 56 also can be a film of liquid impermeable material rendered permeable by a multiplicity of apertures therethrough. Layer 56 further can be totally or partially elastic, for example, by making layer 56 of an elastomeric material.
The direction of stretch can be in the longitudinal direction, transverse direction, or multiple directions. Generally, the direction of stretch is determined during the manufacture of the elastomeric material, and is related to the molecular orientation of the manufactured elastomeric material. Suitable elastic materials are described in the aforementioned u.s. Patent Pat.
No. 4,940,464. One desired permeable layer 56 is a spunbond polypropylene web having a basis weight of about 25 gsm.
Layer 40 includes a pair of side flaps 58 that have respective flap distal edges 60. Each flap distal edge 60 has a flap elastic member 62 elastically associated therewith. Each flap elastic member 62 is desirably three strands of Lycra~ 940 decitex that are attached at their ends at an elongation of about 250%. Each individual strand in a respective elastic member 62 is spaced from another adjacent elastic strand by about 3 mm. These elastic strands can be obtained form E. I. DuPont De Nemours Company, Wilmington, Delaware. Each elastic member 62 can also be one or more strands of the above described elastic, or can be made of other suitable elastic materials such as natural rubber, synthetic rubber, or thermoplastic elastomeric polymers. These elastic materials may also be heat-shrinkable or heat-elasticizable, and can also be single or multiple ribbons of elastic material. As illustrated in Fig. 2, each uppermost single elastic member 62 may be about level with or about at the same height as a corresponding absorbent side portion 50.
Also, flap elastic members 62 are generally positioned between layer 40 and layer 56. If desired, each flap elastic member 62 can be located at a greater height than or above a respective flap distal edge 60 and the outermost edge of an absorbent side portion 50, and in this case would be sandwiched by layer 56.
Layer 40 is continuous in the transverse or lateral direction in that it extends below or underneath absorbent structure 38. In Fig. 7, ~l~27&~
layer 40 extends longitudinally beyond absorbent front end 49 and absorbent back end 51, and the extensions of layer 40 are folded over and attached to absorbent structure 38 to form waist dams 41.
With reference to Fig. 3, another form of the present invention is illustrated in which absorbent structure 38 does not include tissue wrap 46. One of the unique features of the present invention is that it provides for direct depositing of absorbent material 44 on layer 40, which desirably is liquid impermeable. By "direct deposition", "directly depositing", or variations thereof, is meant that the fluff and/or SAM particles, or other absorbent material or materials, are deposited, formed, laid, or the like, directly on liquid impermeable layer 40 and are not encased within tissue wrap 46 or any similar porous structure that is disposed between absorbent material 44 and liquid impermeable layer 40. Absorbent material 44 may be directly deposited in any suitable manner, such as by air-laying or wet-laying. In most cases, it is desired that absorbent material 44 be provided with some type of mechanism for ensuring that it maintains its integrity and shape when being deposited on layer 40 and thereafter during the manufacturing process and use by the consumer.
If an air-laying process is used, synthetic fibers may be intermixed with the fluff and/or SAM by means of a meltblowing process so that the tacky synthetic fibers provide sufficient adherence to and between the fluff and SAM to ensure their integrity in the desired shape and position on layer 40. Water may also be sprayed or otherwise delivered to the fluff and/or SAM during the air-laying process in order to provide hydrogen bonding to ensure the integrity of the absorbent material. The absorbent material 44 can also be mechanically treated in order to maintain the integrity of the desired shape, and such mechanical treating includes passing the absorbent structure through a pair of nip rolls in order to compress the material together.
Absorbent material 44 can comprise, in one specific embodiment, an air-laid nonwoven web comprising about 80 percent by weight fibrous superabsorbent material and about 20 percent by weight polymeric binder fibers. The fibrous superabsorbent materials have a denier of ~227~
about 9 d and a length of about 12 millimeters. Suitable fibrous superabsorbent materials are available from Technical Absorbents Ltd.
of the United Kingdom under the trade-mark OASIS. The polymeric binder fibers have a denier of about 3 d and a length of about 6 millimeters. Such binder fibers may be bicomponent fibers comprising about 50 percent by weight polyethylene and about 50 percent by weight polypropylene in a concentric sheath-core configuration. Suitable bicomponent binder fibers are available from Danaklon a/s of Varde, Denmark, under the trade-mark Danaklon AL
Thermal-C. Such a composite web may be oven fused after air-laying for five minutes at a temperature of about 150 degrees Celsius. The composite web may have a basis weight of about 200 grams per square meter.
Other methods are known or may become known, as well as other absorbent materials, that permit directly depositing absorbent material 44 on layer 40. Absorbent material 44 is attached to layer 40 by the same mechanism that maintains the integrity of absorbent material 44, or may be attached by use of any suitable adhesive or by other types of bonding, such as thermal, ultrasonic, or the like.
Absorbent structure 38 may or may not include weakened areas 54 that assist in forming absorbent structure 38 in a generally U-like shape.
Referring now to Fig. 4, absorbent structure 38 does not include absorbent side portions 50 formed by weakened areas 54, as is the case in Figs. 2-3. In Fig. 4, each side flap 58 includes a portion of layer 40 sandwiched between permeable layer 56. Similar to the absorbent structure in Fig. 3, the absorbent structure 38 of Fig. 4 is also formed by directly depositing absorbent material 44 on layer 40. Absorbent structure 38 and layer 40 are then partially enveloped by permeable layer 56 with surge layer 55 positioned on top of absorbent structure 38.
Referring to Fig. 5, there is illustrated a partially fragmented, exploded, elevational view of the invention illustrated in Fig. 4 with the side flaps 58 in a flat or horizontal condition. In one method of the present invention, a continuously moving backsheet 20 ~1 22 7~ ~
has waist elastic adhesive 64 intermittently applied in a lateral direction for adhering a waist elastic 66 thereto. Waist elastic 66 is preferably a heat-shrinkable elastic that is activated during the manufacturing process, and generally at the end of the process in order to provide elasticity at the front waist section 24 and back waist section 28 (Fig. 7). Waist elastic adhesive 64, as well as the following adhesives to be described, can be made of any suitable adhesive and applied in any suitable pattern. Such adhesives can be obtained from Findley Adhesives, Inc., Wauwatosa, Wisconsin. The adhesives can be applied in any manner such as spraying, slot-coat extrusion, printing, or the like. The adhesives can be sprayed in any desired configuration or design such as continuous or discontinuous beads, discontinuous or continuous swirls, melt-blown, pattern, spray pattern, or the like. Construction adhesive 68 is then applied to continuously moving backsheet 20. Separately, continuously moving liquid impermeable layer 40 has absorbent material 44 directly deposited thereon. Flap elastic members 62 are applied in a stretched condition to side flaps 58 of layer 40 and are attached at their ends to side flaps 58 by flap elastic adhesive 72.
Separately, permeable layer 56 has adhesive 70 applied thereto, and is then brought together with layer 40, absorbent material 44, and flap elastic members 62, and is folded therearound. This joined structure of layer 40, absorbent material 44, flap elastic members 62, and layer 56 is positioned on construction adhesive 68. Surge adhesive 74 is applied on permeable layer 56 for attaching surge layer 55 thereto. This describes one method in which the identified elements are brought together in one form of the present invention.
Other methods or steps are possible, such as joining the elements in a different sequence, joining the elements in a different positional relationship, or the like. The present invention further contemplates that the attachment of elements can be accomplished other than by adhesives, such as by ultrasonic bonding, heat bonding, fiber entanglement, and the like.
Referring now to Fig. 6, a second method of the present invention is illustrated in which tissue wrap 46 has been placed around absorbent material 44, and weakened areas 54 have been provided to define .~1 22 7~ tJ3 absorbent central portion 48 and absorbent side portions 50. After absorbent structure 38 has been formed, it is then positioned on layer 40 and attached thereto by structure adhesive 76. Backsheet 20, waist elastics 66, and surge layer 55 can then be joined together with layer 40, layer 56, and absorbent structure 38 in any suitable manner.
Turning now to Fig. 7, the construction of an individual training pant 10 will be explained in steps that occur subsequently to those described with reference to Fig. 5. If desired, portions of backsheet 20 can be cut, by any suitable device, in order to form leg cut-outs 78 that will later form leg openings 16. Leg elastics 80 are then applied in a curved fashion as illustrated in Fig. 7.
Alternatively, leg elastics 80 can be applied in a straight or linear fashion parallel to longitudinal centerline 22, as is well known in the art. In forming leg-cutouts 78, four ears 82 are formed and will become portions of side sections 32 in the finished training pant 10.
Each ear 82 has an elastic area 84 elastically associated therewith.
Elastic areas 84 can be formed by multiple strands of elastic material arranged in any orientation, such as parallel, intersecting, or both. Elastic areas 84 can be a film or laminate of elastomeric material. Various materials and examples of providing elasticity at ears 82 are described in U.S. Patent No. 4,940,464 and U.S. Patent Application Serial No. 08/043,132 filed on March 25, 1993.
These two references also disclose materials or methods of incorporating leg elastic members 80, as well as waist elastics 66 in their respective front and back waist sections 24, 28. Backsheet 20 further can be made of a single layer of elastic material, or a layer of elastic material suitably joined with other non-elastic layers, for example, a stretch-bonded laminate. After backsheet 20 has been cut, it is then folded along a fold-line generally perpendicular to longitudinal centerline 22 so that the adjacent pairs of ears 82 can be attached or bonded together to form training pant 10 with waist opening 14 and leg opening 16.
- ~12~70~
While this invention has been described as having a preferred embodiment, it will be understood that it is capable of further modifications. This application is therefore intended to cover any variations, equivalents, uses, or adaptations of the invention following the general principles thereof, and including such departures from the present disclosure as come or may come within known or customary practice in the art to which this invention pertains and falls within the limits of the appended claims.
Claims (26)
1. A disposable absorbent child's training pant, comprising:
a generally liquid permeable pant body comprising a front waist section, a back waist section, a crotch section, a waist opening, and a pair of leg openings, an absorbent structure disposed in said pant body at least at said crotch section, said absorbent structure comprising a liquid impermeable layer and an absorbent particulate material directly deposited on said liquid impermeable layer, a pair of longitudinally extending liquid impermeable side flaps associated with said absorbent structure, each said liquid impermeable side flap having a flap distal edge, and a flap elastic member elastically associated with each said flap distal edge for gathering a respective said liquid impermeable side flap.
a generally liquid permeable pant body comprising a front waist section, a back waist section, a crotch section, a waist opening, and a pair of leg openings, an absorbent structure disposed in said pant body at least at said crotch section, said absorbent structure comprising a liquid impermeable layer and an absorbent particulate material directly deposited on said liquid impermeable layer, a pair of longitudinally extending liquid impermeable side flaps associated with said absorbent structure, each said liquid impermeable side flap having a flap distal edge, and a flap elastic member elastically associated with each said flap distal edge for gathering a respective said liquid impermeable side flap.
2. The pant of claim 1 wherein said pant body is elastic.
3. The pant of claim 1 wherein said absorbent structure defines an absorbent central portion and a pair of absorbent side portions, said absorbent central portion having a different absorbent capacity than one of said absorbent side portions.
4. The pant of claim 1 wherein said side flaps are integral with said liquid impermeable layer.
5. The pant of claim 1 wherein said liquid impermeable layer extends longitudinally beyond and is folded over said absorbent particulate material to form a waist dam.
6. The pant of claim 1 further comprising a surge layer disposed with said absorbent structure.
7. A disposable absorbent pant, comprising:
a pant body comprising an interior space, a waist opening, a pair of leg openings, and a crotch section, an absorbent structure disposed in said interior space at said crotch section, said absorbent structure comprising an absorbent material disposed on a liquid impermeable layer, said liquid impermeable layer comprising a pair of side flaps having respective distal edges extending laterally beyond said absorbent material, and a flap elastic member elastically associated with each said distal edge for gathering a respective said side flap.
a pant body comprising an interior space, a waist opening, a pair of leg openings, and a crotch section, an absorbent structure disposed in said interior space at said crotch section, said absorbent structure comprising an absorbent material disposed on a liquid impermeable layer, said liquid impermeable layer comprising a pair of side flaps having respective distal edges extending laterally beyond said absorbent material, and a flap elastic member elastically associated with each said distal edge for gathering a respective said side flap.
8. The pant of claim 7 wherein said pant body is liquid impermeable.
9. The pant of claim 7 wherein said pant body is liquid permeable.
10. The pant of claim 7 wherein each said pant body is elastic.
11. The pant of claim 7 wherein said liquid impermeable layer extends longitudinally beyond and is folded over said absorbent material to form a waist dam.
12. The pant of claim 7 further comprising a surge layer disposed with said absorbent structure.
13. The pant of claim 7 wherein said absorbent structure further comprises a longitudinally extending weakened area forming a pair of absorbent side portions.
14. A disposable absorbent article, comprising:
an elastic backsheet, a liquid impermeable layer disposed with said elastic backsheet, an absorbent material directly deposited on said liquid impermeable layer, said liquid impermeable layer comprising a pair of longitudinally extending side flaps having respective flap distal edges that extend laterally beyond said absorbent material, and a flap elastic member elastically associated with each said flap distal edge for gathering a respective said side flap.
an elastic backsheet, a liquid impermeable layer disposed with said elastic backsheet, an absorbent material directly deposited on said liquid impermeable layer, said liquid impermeable layer comprising a pair of longitudinally extending side flaps having respective flap distal edges that extend laterally beyond said absorbent material, and a flap elastic member elastically associated with each said flap distal edge for gathering a respective said side flap.
15. The article of claim 14 wherein said backsheet comprises a front waist section, a back waist section, a crotch section, a pair of side sections, and forms a waist opening and a pair of leg openings.
16. The article of claim 15 wherein said backsheet is liquid permeable.
17. The article of claim 15 wherein said backsheet is liquid impermeable.
18. The article of claim 15 wherein said liquid impermeable layer extends longitudinally beyond and is folded over said absorbent material to form a waist dam.
19. The article of claim 15 wherein said absorbent material comprises a longitudinally extending weakened area forming a pair of absorbent side portions.
20. The article of claim 15 further comprising a surge layer disposed with said absorbent material.
21. A method of making a disposable absorbent article, comprising the steps of:
providing a liquid impermeable layer of material, directly depositing an absorbent material on the liquid impermeable layer of material such that distal edges of the liquid-impermeable layer extend laterally beyond the absorbent material, providing a liquid permeable sheet of material, positioning the liquid impermeable layer of material and the liquid permeable sheet of material together with the absorbent material therebetween, and elastically associating an elastic member in each of the distal edges of the liquid impermeable layer for gathering the distal edges.
providing a liquid impermeable layer of material, directly depositing an absorbent material on the liquid impermeable layer of material such that distal edges of the liquid-impermeable layer extend laterally beyond the absorbent material, providing a liquid permeable sheet of material, positioning the liquid impermeable layer of material and the liquid permeable sheet of material together with the absorbent material therebetween, and elastically associating an elastic member in each of the distal edges of the liquid impermeable layer for gathering the distal edges.
22. The method of claim 21 further comprising the step of forming a weakened area in the absorbent material to form a pair of absorbent side portions.
23. The method of claim 21 further comprising the steps of providing a backsheet having opposed longitudinal edges, joining the disposable absorbent article on the backsheet, folding the backsheet intermediate the longitudinal edges, and bonding portions of the longitudinal edges together to form a pant body having a waist opening and a pair of leg openings.
24. A method of making a disposable absorbent article, comprising the steps of:
providing a backsheet having longitudinal edges, positioning an absorbent structure on the backsheet, the absorbent structure comprising an absorbent material on a liquid impermeable layer such that distal edges of the liquid-impermeable layer extend laterally beyond the absorbent material, elastically associating an elastic member in each of the distal edges of the liquid impermeable layer, and bonding portions of the longitudinal edges of the backsheet together to form a pant body having a waist opening and a pair of leg openings.
providing a backsheet having longitudinal edges, positioning an absorbent structure on the backsheet, the absorbent structure comprising an absorbent material on a liquid impermeable layer such that distal edges of the liquid-impermeable layer extend laterally beyond the absorbent material, elastically associating an elastic member in each of the distal edges of the liquid impermeable layer, and bonding portions of the longitudinal edges of the backsheet together to form a pant body having a waist opening and a pair of leg openings.
25. The method of claim 24 wherein the absorbent material is directly deposited on the liquid impermeable layer.
26. The method of claim 24 further comprising the step of forming a weakened area in the absorbent structure to form a pair of absorbent side portions.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US17157993A | 1993-12-22 | 1993-12-22 | |
| US171,579 | 1993-12-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2122700A1 true CA2122700A1 (en) | 1995-06-23 |
Family
ID=22624298
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2122700 Abandoned CA2122700A1 (en) | 1993-12-22 | 1994-05-02 | Training pant with a film-backed absorbent and method of making the same |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2122700A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1603502B1 (en) | 2003-03-07 | 2016-04-27 | SCA Hygiene Products AB | Pant-shaped garment with improved fit |
-
1994
- 1994-05-02 CA CA 2122700 patent/CA2122700A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1603502B1 (en) | 2003-03-07 | 2016-04-27 | SCA Hygiene Products AB | Pant-shaped garment with improved fit |
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