CA2190287A1 - Disposable absorbent training pant having improved recumbent waste containment features - Google Patents
Disposable absorbent training pant having improved recumbent waste containment featuresInfo
- Publication number
- CA2190287A1 CA2190287A1 CA 2190287 CA2190287A CA2190287A1 CA 2190287 A1 CA2190287 A1 CA 2190287A1 CA 2190287 CA2190287 CA 2190287 CA 2190287 A CA2190287 A CA 2190287A CA 2190287 A1 CA2190287 A1 CA 2190287A1
- Authority
- CA
- Canada
- Prior art keywords
- elastic
- pant
- waist
- barrier
- absorbent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Landscapes
- Absorbent Articles And Supports Therefor (AREA)
- Orthopedics, Nursing, And Contraception (AREA)
Abstract
A disposable absorbent training pant having improved recumbent waste containment features. The training pant includes an elastic waist barrier selectively joined to a waist peripheral region of the training pant to provide improved fit at the waist, and improved waste containment performance.
Description
21 90~87 PATENT
DISPOSABLE ABSORBENT TRAINING PANT HAVING IMPROVED RECUMBENT
WASTE CONTAINMENT FEATURES
B~ckgrol~nd of the Invention The present invention relates to disposable absorbent training pants, and more particularly to a disposable absorbent training pant having improved waste containment for children in a recumbent position, such as when they are asleep in bed.
Disposable absorbent articles have been designed and used for various purposes. For example, some have been designed for use as diapers for babies; as training pants for younger children in the potty training stage, generally between the age of 18 months to 36 months; or as incontinence products for adults. One of the most important functions of any disposable absorbent article is that it contain liquid and other waste material. Failure to do so results in-leakage and wetting of the clothes, which is undesirable to the wearer and caregivers.
Generally, leakage will occur at the leg openings and the waist opening. In order to prevent leakage at these 2 ! 902&7 openings, stretched elastic members have been attached at the leg and waistopenings to provide an elastic seal, at the wearer's legs and waist. Current absorbent articles include various designs and constructions incorporating these elastic members with the intent of containing liquid and waste matter. They have not, to date, been entirely successful in this area.
For example, if a child wearing a current training pant urinates at a flow rate, or in a quantity, that exceeds the absorption rate, or absorption capacity, of the training pant, the urine can pool at the leg and waist openings, and eventually leak through the openings. This leakage is likely to occur at the leg openings during the daytime when the child is upright, and at the waist opening during the night when the child is asleep.
Waist leakage for boys, particularly when laying down, is generally of greater concern than for girls, since boys urinate at an area relatively nearer the walstline; whereas girls urinate relatively closer to the crotch area.
Another reason for this waist leakage for boys is that some current training pants may not have sufficient absorption capacity at the front waist area, or may not absorb urine at a rapid enough rate to prevent leakage in this area.
Attempts to overcome this front waist leakage have included increasing the absorption capacity by adding more absorbent 21qQ~7 fluff or superabsorbent material, or both. Although this does increase the absorption capacity at the front, leakage still occurs when the flow rate of urine exceeds the absorption rate of the absorbent material.
However, there is a problem with increased absorbency at the front waist area in that it can become quite heavy from absorbing the urine. This increased weight tends to pull the waist of the training pant below the waistline and away from the child's body, thereby forming a gap between the pant and child through which urine can leak.
Finally, all of the above problems are of greater magnitude for those older children who continue to "bed wet", i.e., experience nocturnal incontinence, beyond the usual potty training age. These older children are generally three to six years old, and their rate of flow and volume of urine is much greater than younger children.
In view of the above, it is apparent that there still exists a need for improving waste containment and fit at the child's waist, particularly when the child is laying down.
Summary of the Invention In response to the discussed difficulties and problems encountered in the prior art, a disposable absorbent training pant having improved recumbent waste containment features has been discovered.
~1 90287 In one form of the present invention there is provided a disposable absorbent training pant having a three-dimensional pant body that defines a pant interior, a waist opening, and a pair of leg openings. The pant body includes a front panel, a crotch panel, a back panel, and an absorbent structure in the pant interior. A waist peripheral region has a waist peripheral edge generally circumscribing the waist opening. An elastic waist barrier in the pant interior is joined to the waist peripheral region near the waist peripheral edge, and extends vertically downwardly from the waist peripheral edge to form a trough.
More particularly, the invention provides a disposable absorbent pant, comprising: a three-dimensional pant body defining a pant interior, an interior surface, a waist opening, and a pair of leg openings, said pant body including a front panel, a crotch panel, a back panel, and an absorbent structure in said pant interior, a waist peripheral region having a waist peripheral edge generally circumscribing said waist opening, and an elastic waist barrier in said pant interior and being joined to said waist peripheral region near said waist peripheral edge thereof, said elastic waist barrier extending vertically downwardly from said waist peripheral edge to form a trough, said elastic waist barrier having a hydrohead value of at least about 30 centimeters or more of water to provide sufficient resistance to liquid penetration to allow adequate time for absorption by said absorbent structure.
21 qO287 In another form of the present invention there is provided a disposable absorbent training pant having a front panel, a back panel, and a crotch panel between the front panel and back panel. The front panel has a pair of elastic front side sections and a front central section, and the back panel has a pair of elastic back side sections and a back central section. An absorbent structure is provided with an absorbent front edge and a pair of absorbent side edges. A
pair of side seams join the elastic front side sections to the elastic back side sections to define a pant interior, a waist opening, and a pair of leg openings. An elastic waist barrier includes a pair of elastic side portions, an elastic central portion, and opposite side edges. The elastic central portion is joined while in a stretched condition to the front central section by a generally horizontal continuous liquid barrier bond line, and the elastic side portions are joined while in a generally relaxed condition to 4a the elastic front side sections. A pair of generally ~ vertical continuous liquid barrier bond lines extending vertically downwardly from the generally horizontal continuous liquid barrier bond line form a trough.
In still another form of the present invention there is provided a disposable absorbent training pant having a three dimensional pant body defining a pant interior, a waist opening, and a pair of leg openings. An absorbent structure is disposed in the pant interior. A waist peripheral region has a waist peripheral edge generally circumscribing the waist opening, and an elastic waist barrier is joined to the waist peripheral region to form a trough. The elastic waist barrier includes a gatherable layer and a mechanism for elasticizing the gatherable layer.
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. l illustrates a front perspective view of one type of a disposable absorbent training pant incorporating the principles of the present invention;
21 ~0287 Fig. 2 illustrates a top plan, partially broken away view of - the training pant in Fig. 1 in a partially disassembled, stretched flat state;
Fig. 3 illustrates a cross-sectional view of Fig. 2 taken along line 3-3 and viewed in the direction of the arrows;
Figs. 4-6 illustrate exploded side views of elastic waist barriers according to the principles of the present invention; and Fig. 7 illustrates a representative light box, clamps, and weights for use with the described TEST PROCEDURE.
Detailed Description Referring to Fig. 1, disposable absorbent training pant 10 of the present invention comprises a three ~; ?~ional pant body 12 comprising a front panel 14, a back panel 16, and a crotch panel 18 interconnecting front panel 14 with back panel 16.
A pair of tearable, nonrefastenable side seams 20 joined selected portions of front panel 14 and back panel 16 to define a pant interior 22, a waist opening 24, and a pair of leg openings 26. A waist peripheral region 28 of pant body 12 includes a waist peripheral edge 30 generally circumscribing waist opening 24. Pant body 12 further includes an interior surface 32, which may or may not be the -surface that directly contacts the child's skin.
The use of the term "disposable" in describing absorbent ~ training pant 10 means that it is designed to be used until soiled, either by urination, defecation, or otherwise, and then discarded-rather than being washed and reused again. In describing pant body 12 as "three dimensional", it is meant that it has a waist opening 24 and a pair of leg openings 26 formed by front panel 14, back panel 16, and side seams 20.
Thus, a three dimensional garment is different from a "two dimensional" garment, such as a baby diaper, that utilizes refastenable adhesive tapes or mechanical fasteners, which permit the diaper to be fastened and refastened multiple times during use.
Training pant 10 is suitable for use for both boys and girls in the potty training stage, which generally occurs in the age range of about 18 months to about 36 months. However, some boys and girls exceed this potty training range and may continue to wet their clothes up to an age of about 6 years old. Of particular concern are boys who are in the age range of about 3 to about 6 years old, since the target zone of urination for boys is generally nearer the waistline, whereas the target zone for girls is generally nearer the crotch area. Consequently, for boys, there is an increased probability of leakage at the pant waist, and particularly when the child is in a recumbent position during sleep, either at night or during daytime naps. Most of the leakage in a recumbent position occurs during the time the child is asleep in a prone or side position. The term "prone" refers to a position in which the front of the child's body faces 2~ 9~2~7 the supporting surface, such as the child's bed. The term - "supine" refers to a position in which the child's back faces the supporting surface. The term "side" refers to a position in which the-child's side, either the left or the right, faces the supporting surface. The term "recumbent" refers to a posture or position assumed by the child when lying down, and will include those positions referred to as prone, supine, side, or a position somewhere between any two.
Disposable absorbent training pant 10 of the present invention specifically addresses the earlier-described problems of increased leakage and improper fit at the waist area when the child is in a recumbent position. These two problems of increased leakage and improper fit are significantly minimized by the provision of a unique elastic waist barrier 34. When joined to waist peripheral region 28, the unique elastic waist barrier 34 forms a trough 36 for cont~; n; ng urine so that it does not leak at waist opening 24, and provides the necessary time for the urine to be absorbed. Additionally, elastic waist barrier 34 provides improved elastic seal characteristics at the waist to prevent it from separating or gapping away from the child's body as the absorbent becomes heavier due to urine absorption.
Referring primarily to Fig. 2, pant body 12 includes a liquid permeable topsheet 38, a liquid impermeable backsheet 40, and an absorbent structure 42 suitably joined between topsheet 38 and backsheet 40.
2~ 9u2~7 Topsheet 38 is compliant, soft feeling, and nonirritating to - the child's skin, and permits liquids to readily penetrate through its thickness. Topsheet 38 may be manufactured from a wide range of materials, such as porous foams, reticulated foams, apertured plastic films, natural fibers, synthetic fibers, or from a combination of natural and synthetic fibers. If topsheet 38 comprises substantially hydrophobic material, the hydrophobic material can be treated with a surfactant or otherwise processed in order to impart a desired level of wettability and hydrophilicity. One such surfactant is a 0.28% Triton X-102 surfactant. A suitable liquid permeable topsheet 38 is a nonwoven bicomponent web having a basis weight of about 27 grams per square meter (gsm). The nonwoven bicomponent web may be a spunbond bicomponent web, or a bonded carded bicomponent web.
Suitable bicomponent staple fibers include a polyethylene/polypropylene bicomponent fiber available from CHISSO Corporation, Osaka, Japan. In this particular bicomponent fiber, the polypropylene forms the core and the polyethylene forms the sheath of the fiber. Other fiber orientations are possible, such as multi-lobe, side-by-side, end-to-end, or the like.
Backsheet 40 is impermeable to liquids and is preferably manufactured from a thin plastic film, although other flexible liquid impermeable materials may also be used.
Backsheet 40 prevents the exudates absorbed and contained in absorbent structure 42 from wetting articles which contact training pant lO, such as bed sheets and clothing. A
21 ~J 2 ~ 7 suitable liquid impermeable backsheet 40 is a l.0 mil ~ polyethylene film obtainable from Edison Plastics Company of South Plainfield, New Jersey. Backsheet 40 can be embossed and/or matte-finished to provide a more clothlike appearance.
Furthermore, backsheet 40 can permit vapors to escape from absorbent structure 42, while still preventing exudates from passing through backsheet 40. A suitable "breathable"
material that permits vapors to escape from absorbent structure 42, while preventing liquid exudates from passing through backsheet 40, is a material composed of a microporous polymer film or a nonwoven fabric that has been coated or otherwise treated to impart a desired level of liquid impermeability. A suitable microporous film is a PMP-l film material, which is available from Mitsui Toatsu Chemicals, Inc., Tokyo, Japan, or an XK0-8044 polyolefin film available from 3M Company, Minneapolis, Minnesota.
Backsheet 40 and topsheet 38 are desirably congruent, i.e., of the same size and shape. If desired or nec~ss~ry, either topsheet 38 or backsheet 40 can have a different size and/or shape from the other. Backsheet 40 is positioned on the side of absorbent structure 42 opposite from topsheet 38, and is preferably attached to absorbent structure 42 by any suitable means well known in the art. For example, backsheet 40 may be secured to absorbent structure 42 by a uniform continuous layer of adhesive, a patterned layer of adhesive, or an array of separate lines or spots of adhesive. Suitable adhesives can be obtained from Findley Adhesives, Inc., Wauwatosa, 21 qG2~7 Wisconsin, and can be applied in any manner well known in the art.
Absorbent structure 42 can be any structure which is generally compressible, conformable, nonirritating to the child's skin, and capable of absorbing and retaining liquids and certain body exudates. Absorbent structure 42 can be manufactured in a wide variety of sizes and shapes, and from a wide variety of liquid absorbent materials commonly used in the art. For example, absorbent structure 42 can comprise pulp fluff, superabsorbent material, or a combination thereof. If in combination, the pulp fluff and the superabsorbent material can be blended together, or comprise discrete layers of fluff and discrete layers of superabsorbent material. Various types of wettable, hydrophilic fibrous material include naturally occurring organic fibers composed of intrinsically wettable material, such as cellulosic fibers; synthetic fibers composed of cellulose or cellulose derivatives, such as rayon fibers;
inorganic fibers composed of an inherently wettable material, such as glass fibers; and synthetic fibers composed of a nonwettable, thermoplastic polymer, such as polypropylene fibers, which have been hydrophilized by appropriate means.
- The fibers may be hydrophilized, for example, by treatment with silica, treatment with a material which has a suitable hydrophilic moiety, or the like.
Suitable superabsorbent materials may be organic or inorganic. Suitable inorganic superabsorbent materials 2i 9~;'87 include, by way of example, absorbent clays and silica gels.
Suitable organic superabsorbent materials include natural materials, such as pectin and peat moss, as well as synthetic materials, such as synthetic hydrogel polymers. Suitable superabsorbent materials are available from various commercial vendors, such as Dow Chemical Company, Hoechst-Celanese Corporation, and Allied Colloids, Inc. Typically, a superabsorbent material is capable of absorbing at least about 15 times its weight in water, and desirably is capable of absorbing more than about 25 times its weight in water.
In one embodiment, absorbent structure 42 is generally rectangular in shape, and comprises a blend of wood pulp fluff and superabsorbent material. One preferred type of pulp fluff is identified with the trade designation CR1654, available from Kimberly-Clark Corporation, Neenah, Wisconsin, and is a bleached, highly absorbent sulfate wood pulp cont~;ning primarily soft wood fibers. The fluff and superabsorbent material in absorbent structure 42 are present in a ratio Or about 9 grams to about 20 grams fluff to about 7 grams to about 14 grams superabsorbent material. The absorbent structure 42 has a density within the range of about 0.10 grams per cubic centimeter to about 0.35 grams per cubic centimeter. The absorbent structure 42 may or may not be wrapped or encompassed by a suitable tissue wrap that maintains the integrity and/or shape of the absorbent structure 42.
2 1 qo2~,7 For purposes of description herein, topsheet 38 and backsheet - 40 are of the same size and shape, and as viewed in Fig. 2, define a pant front edge 44, a pant back edge 46, and a pair of leg cutouts-48, which form leg openings 26 in the finished product, as illustrated by training pant 10 in Fig. 1.
A containment flap S0 is disposed on each side of absorbent structure 42. As illustrated in Fig. 2, each containment flap 50 includes a proximal edge 52, a distal edge 54, and a flap elastic 56 elastically associated in each distal edge 54. Each proximal edge 52 of a containment flap 50 is adhesively attached to topsheet 38 just slightly spaced apart from an absorbent side edge 58. Each flap elastic 56 is adhesively joined in a stretched condition to a respective distal edge 54, in a manner well known in the art. The respective ends of each containment flap 50 are coincident with pant front edge 44 and pant back edge 46, although this is not a necessary requirement.
Containment flaps 50 are, like topsheet 38 and backsheet 40, made of a suitable flexible material. As used herein, the term "flexible~ refers to materials which are compliant and will readily conform to the general shape~and contours of the child's body. Each flap elastic 56 can be a single or 2~ multiple ribbon or strand of suitable elastic material, which when joined in a stretched manner to a respective containment ' flap 50, will contract a distal edge 54 sufficiently away from topsheet 38 in order to form a channel or pocket between a containment flap 50 and topsheet 38, thereby permitting the 21 90~S7 retention of body exudates. Containment flaps s0 can be manufactured from a wide variety of materials such as polypropylene, polyester, rayon, nylon, foams, plastic films, elastic films, and the like. Various manufacturing techniques can be used to make containment flaps 50, such that they may be woven, nonwoven, spunbond, carded, or the like. Containment flaps 50 may also be made of the same material as that of which topsheet 38 is made.
Flap elastics 56 can be made of any suitable elastic material, and one suitable such material and construction is a plurality of strands of LYCRA~ 940 decitex that are joined at their ends to respective distal edges 54 while at an elongation of about 300 percent. Each individual strand is spaced from an adjacent strand by about 3 millimeters. These types of elastic strands can be obtained from E.I. DuPont de Nemours Company, Wilmington, Delaware. Other suitable elastic materials include natural rubber, synthetic rubber, or thermoplastic elastomeric polymers. These elastic materials may also be heat-elasticizable, and can be single or multiple ribbons of elastic material.
Other constructions of suitable containment flaps are described in U.S. Patent No. 4,704,116 issued November 3, 1987 to Enloe.
~s illustrated in Fig. 2, pant body 12 is in a partially disassembled, stretched flat condition, and as previously 21 ~02S7 mentioned includes front panel 14, back panel 16, and crotch panel 18. The total product, or pant, length is that length of pant body 12 in Fig. 2 measured between pant front edge 44 and pant back edge 46 in a vertical direction. By "vertical direction" is meant a top-to-bottom or bottom-to-top direction with respect to Fig. 2. Similarly, the term "horizontal direction" re~ers to a direction perpendicular to the vertical direction. Generally speaking, each of the panel lengths, that is front panel length 60, crotch panel length 62, back panel length 64, will have a length approximately 1/3 the total product length measured between pant front edge 44 and pant back edge 46.
In Fig. 2, front panel 14 comprises a front central section 66 and a pair of elastic front side sections 68, 70 having respective front side edges 72, 74. Similarly, back panel 16 comprises a back central section 76 and a pair of elastic back side sections 78, 80 having respective back side edges 82, 84. During the manufacturing process, pant body 12 is folded to substantially align front side edge 72 with back side edge 82, and front side edge 74 to back side edge 84.
Thereafter, these aligned edges are suitably joined together, such as by ultrasonic bonding, in order to form side seams 20 (Fig. 1). One method for aligning and bonding a folded article is described in U.S. Patent No. 5,046,272 issued September 10, 1991 to Vogt et al.
~1902~7 Prior to the folding and bonding to form side seams 20, a pair of leg elastic members 86 are suitably joined to pant body 12 at least at crotch panel 18. Each leg elastic member 86 can be any suitable construction well known in the art.
One suitable construction is that described in U.S. Patent No. 4,940,464 issued July 10, 1990 to VanGompel et al.
Another suitable construction for a leg elastic member 86 is a stretch bonded laminate comprising any suitable material having elastic properties. Examples of such suitable elastic materials include films or layers of natural rubber, synthetic rubber, or thermoplastic elastomeric polymers.
These materials can be arranged or manufactured as panels, or as single or multiple threads, filaments or ribbons. The materials may also be heat-elasticizable. The elastic materials of which flap elastics 56 are made may also be utilized in leg elastic members 86. Each leg elastic member 86, as a stretch bonded laminate, comprises at least one gatherable layer and one elastic layer or multiple threads of elastic material. As used throughout this description of the invention, the term "elastic" refers to that property of a material or composite or laminate that causes it to recover its original size and shape after removal of a force causing the deformation, and is expressed as a percent. The term "join", "joining", or variations thereof, when used in describing the relationship between two or more elements, means that the elements can be connected together in any suitable manner, s~ch as by heat sealing, ultrasonic bonding, 2 i 9~87 thermal bonding, adhesives, stitching, or the like; these elements can be joined directly together, or may have one or more elements interposed between them, all of which are connected together. Finally, the phrase "elastically joined", or variations thereof, generally describes the joining of an elastic member to a non-elastic member such that the two joined members exhibit elasticity or elastic properties. A suitable stretch bonded laminate construction for use as a leg elastic member 86 comprises two gatherable layers of spunbond polypropylene having a basis weight of about 14 grams per square meter (gsm) with a layer of meltblown elastic material having a basis weight of about 16 gsm therebetween. The layer of elastic material is stretched, the two layers of polypropylene are then joined to the stretched elastic layer, and upon relaxing the layers, the polypropylene layers are gathered by the elastic layer.
Continuing to refer to Fig. 2, elastic front side section 68 and elastic front side section 70 have the same size and shape, and are similarly constructed with the same materials.
Furthermore, elastic front side sections 68, 70 can be separate elastic structures suitably joined to front central section 66, such as that described in U.S. Patent No.
4,940,464 issued July lO, l990 to VanGompel, the contents of which are incorporated by reference herein. In this embodiment, each elastic front side section 68, 70 is a stretch bonded laminate made of any suitable materials, such as those identified in the aforementioned U.S. 4,940,464. In this specific construction, elastic front side section 68 has 21 qa,~at7 -a front edge coincident with pant front edge 44, a side edge - coincident with front side edge 72, and an inner edge so.
Similarly, elastic front side section 70 has a front edge coincident with pant front edge 44, a side edge coincident with front side edge 74, and an inner edge 92.
Similarly, elastic back side section 78 is constructed to have a back edge coincident with pant back edge 46, a side edge coincident with back side edge 82, and an inner edge 94.
Elastic back side section 80 also is constructed to have a back edge coincident with pant back edge 46, a side edge coincident with back side edge 84, and an inner edge 96.
Elastic back side sections 78, 80 can also be separate : elastic structures suitably joined to back central section 76, in a manner similar to that described above for joining : elastic front side sections 68, 70 to front central section 66.
.
In the above description of pant body 12, the gatherable layers of the stretch bonded laminate can be selected from materials that are compatible as portions of either liquid permeable topsheet 38 or liquid impermeable backsheet 40.
For example, the outermost gatherable layer can be liquid impermeable and gatherable, while the innermost gatherable layer can be liquid permeable and gatherable.
To this point in the description, dimensions have not been described for the product or any components thereof.
Hereafter, desired dimensions will be provided, and these dimensions can be determined by the following described - procedure.
- TEST PROCEDURE
EOUIPMENT AND MATERIALS
1. A suitable lightbox 156 (Fig. 7), at least 18 inches wide x 24 inches high, such as catalog number 3670S-052 available from VWR Scientific, 600 C Corporate Court, South Plainfield, NJ 07080. The lightbox is mounted vertically.
2. Two clamps 158, such as Hunt/Boston brand Bulldog Clips HUN02004, available from BT Publix Office Products, Inc., 700 West Chicago Avenue, Chicago, IL 60610, are mounted about 6 inches apart, near the top of the - lightbox 156, as shown in Figure 7.
DISPOSABLE ABSORBENT TRAINING PANT HAVING IMPROVED RECUMBENT
WASTE CONTAINMENT FEATURES
B~ckgrol~nd of the Invention The present invention relates to disposable absorbent training pants, and more particularly to a disposable absorbent training pant having improved waste containment for children in a recumbent position, such as when they are asleep in bed.
Disposable absorbent articles have been designed and used for various purposes. For example, some have been designed for use as diapers for babies; as training pants for younger children in the potty training stage, generally between the age of 18 months to 36 months; or as incontinence products for adults. One of the most important functions of any disposable absorbent article is that it contain liquid and other waste material. Failure to do so results in-leakage and wetting of the clothes, which is undesirable to the wearer and caregivers.
Generally, leakage will occur at the leg openings and the waist opening. In order to prevent leakage at these 2 ! 902&7 openings, stretched elastic members have been attached at the leg and waistopenings to provide an elastic seal, at the wearer's legs and waist. Current absorbent articles include various designs and constructions incorporating these elastic members with the intent of containing liquid and waste matter. They have not, to date, been entirely successful in this area.
For example, if a child wearing a current training pant urinates at a flow rate, or in a quantity, that exceeds the absorption rate, or absorption capacity, of the training pant, the urine can pool at the leg and waist openings, and eventually leak through the openings. This leakage is likely to occur at the leg openings during the daytime when the child is upright, and at the waist opening during the night when the child is asleep.
Waist leakage for boys, particularly when laying down, is generally of greater concern than for girls, since boys urinate at an area relatively nearer the walstline; whereas girls urinate relatively closer to the crotch area.
Another reason for this waist leakage for boys is that some current training pants may not have sufficient absorption capacity at the front waist area, or may not absorb urine at a rapid enough rate to prevent leakage in this area.
Attempts to overcome this front waist leakage have included increasing the absorption capacity by adding more absorbent 21qQ~7 fluff or superabsorbent material, or both. Although this does increase the absorption capacity at the front, leakage still occurs when the flow rate of urine exceeds the absorption rate of the absorbent material.
However, there is a problem with increased absorbency at the front waist area in that it can become quite heavy from absorbing the urine. This increased weight tends to pull the waist of the training pant below the waistline and away from the child's body, thereby forming a gap between the pant and child through which urine can leak.
Finally, all of the above problems are of greater magnitude for those older children who continue to "bed wet", i.e., experience nocturnal incontinence, beyond the usual potty training age. These older children are generally three to six years old, and their rate of flow and volume of urine is much greater than younger children.
In view of the above, it is apparent that there still exists a need for improving waste containment and fit at the child's waist, particularly when the child is laying down.
Summary of the Invention In response to the discussed difficulties and problems encountered in the prior art, a disposable absorbent training pant having improved recumbent waste containment features has been discovered.
~1 90287 In one form of the present invention there is provided a disposable absorbent training pant having a three-dimensional pant body that defines a pant interior, a waist opening, and a pair of leg openings. The pant body includes a front panel, a crotch panel, a back panel, and an absorbent structure in the pant interior. A waist peripheral region has a waist peripheral edge generally circumscribing the waist opening. An elastic waist barrier in the pant interior is joined to the waist peripheral region near the waist peripheral edge, and extends vertically downwardly from the waist peripheral edge to form a trough.
More particularly, the invention provides a disposable absorbent pant, comprising: a three-dimensional pant body defining a pant interior, an interior surface, a waist opening, and a pair of leg openings, said pant body including a front panel, a crotch panel, a back panel, and an absorbent structure in said pant interior, a waist peripheral region having a waist peripheral edge generally circumscribing said waist opening, and an elastic waist barrier in said pant interior and being joined to said waist peripheral region near said waist peripheral edge thereof, said elastic waist barrier extending vertically downwardly from said waist peripheral edge to form a trough, said elastic waist barrier having a hydrohead value of at least about 30 centimeters or more of water to provide sufficient resistance to liquid penetration to allow adequate time for absorption by said absorbent structure.
21 qO287 In another form of the present invention there is provided a disposable absorbent training pant having a front panel, a back panel, and a crotch panel between the front panel and back panel. The front panel has a pair of elastic front side sections and a front central section, and the back panel has a pair of elastic back side sections and a back central section. An absorbent structure is provided with an absorbent front edge and a pair of absorbent side edges. A
pair of side seams join the elastic front side sections to the elastic back side sections to define a pant interior, a waist opening, and a pair of leg openings. An elastic waist barrier includes a pair of elastic side portions, an elastic central portion, and opposite side edges. The elastic central portion is joined while in a stretched condition to the front central section by a generally horizontal continuous liquid barrier bond line, and the elastic side portions are joined while in a generally relaxed condition to 4a the elastic front side sections. A pair of generally ~ vertical continuous liquid barrier bond lines extending vertically downwardly from the generally horizontal continuous liquid barrier bond line form a trough.
In still another form of the present invention there is provided a disposable absorbent training pant having a three dimensional pant body defining a pant interior, a waist opening, and a pair of leg openings. An absorbent structure is disposed in the pant interior. A waist peripheral region has a waist peripheral edge generally circumscribing the waist opening, and an elastic waist barrier is joined to the waist peripheral region to form a trough. The elastic waist barrier includes a gatherable layer and a mechanism for elasticizing the gatherable layer.
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. l illustrates a front perspective view of one type of a disposable absorbent training pant incorporating the principles of the present invention;
21 ~0287 Fig. 2 illustrates a top plan, partially broken away view of - the training pant in Fig. 1 in a partially disassembled, stretched flat state;
Fig. 3 illustrates a cross-sectional view of Fig. 2 taken along line 3-3 and viewed in the direction of the arrows;
Figs. 4-6 illustrate exploded side views of elastic waist barriers according to the principles of the present invention; and Fig. 7 illustrates a representative light box, clamps, and weights for use with the described TEST PROCEDURE.
Detailed Description Referring to Fig. 1, disposable absorbent training pant 10 of the present invention comprises a three ~; ?~ional pant body 12 comprising a front panel 14, a back panel 16, and a crotch panel 18 interconnecting front panel 14 with back panel 16.
A pair of tearable, nonrefastenable side seams 20 joined selected portions of front panel 14 and back panel 16 to define a pant interior 22, a waist opening 24, and a pair of leg openings 26. A waist peripheral region 28 of pant body 12 includes a waist peripheral edge 30 generally circumscribing waist opening 24. Pant body 12 further includes an interior surface 32, which may or may not be the -surface that directly contacts the child's skin.
The use of the term "disposable" in describing absorbent ~ training pant 10 means that it is designed to be used until soiled, either by urination, defecation, or otherwise, and then discarded-rather than being washed and reused again. In describing pant body 12 as "three dimensional", it is meant that it has a waist opening 24 and a pair of leg openings 26 formed by front panel 14, back panel 16, and side seams 20.
Thus, a three dimensional garment is different from a "two dimensional" garment, such as a baby diaper, that utilizes refastenable adhesive tapes or mechanical fasteners, which permit the diaper to be fastened and refastened multiple times during use.
Training pant 10 is suitable for use for both boys and girls in the potty training stage, which generally occurs in the age range of about 18 months to about 36 months. However, some boys and girls exceed this potty training range and may continue to wet their clothes up to an age of about 6 years old. Of particular concern are boys who are in the age range of about 3 to about 6 years old, since the target zone of urination for boys is generally nearer the waistline, whereas the target zone for girls is generally nearer the crotch area. Consequently, for boys, there is an increased probability of leakage at the pant waist, and particularly when the child is in a recumbent position during sleep, either at night or during daytime naps. Most of the leakage in a recumbent position occurs during the time the child is asleep in a prone or side position. The term "prone" refers to a position in which the front of the child's body faces 2~ 9~2~7 the supporting surface, such as the child's bed. The term - "supine" refers to a position in which the child's back faces the supporting surface. The term "side" refers to a position in which the-child's side, either the left or the right, faces the supporting surface. The term "recumbent" refers to a posture or position assumed by the child when lying down, and will include those positions referred to as prone, supine, side, or a position somewhere between any two.
Disposable absorbent training pant 10 of the present invention specifically addresses the earlier-described problems of increased leakage and improper fit at the waist area when the child is in a recumbent position. These two problems of increased leakage and improper fit are significantly minimized by the provision of a unique elastic waist barrier 34. When joined to waist peripheral region 28, the unique elastic waist barrier 34 forms a trough 36 for cont~; n; ng urine so that it does not leak at waist opening 24, and provides the necessary time for the urine to be absorbed. Additionally, elastic waist barrier 34 provides improved elastic seal characteristics at the waist to prevent it from separating or gapping away from the child's body as the absorbent becomes heavier due to urine absorption.
Referring primarily to Fig. 2, pant body 12 includes a liquid permeable topsheet 38, a liquid impermeable backsheet 40, and an absorbent structure 42 suitably joined between topsheet 38 and backsheet 40.
2~ 9u2~7 Topsheet 38 is compliant, soft feeling, and nonirritating to - the child's skin, and permits liquids to readily penetrate through its thickness. Topsheet 38 may be manufactured from a wide range of materials, such as porous foams, reticulated foams, apertured plastic films, natural fibers, synthetic fibers, or from a combination of natural and synthetic fibers. If topsheet 38 comprises substantially hydrophobic material, the hydrophobic material can be treated with a surfactant or otherwise processed in order to impart a desired level of wettability and hydrophilicity. One such surfactant is a 0.28% Triton X-102 surfactant. A suitable liquid permeable topsheet 38 is a nonwoven bicomponent web having a basis weight of about 27 grams per square meter (gsm). The nonwoven bicomponent web may be a spunbond bicomponent web, or a bonded carded bicomponent web.
Suitable bicomponent staple fibers include a polyethylene/polypropylene bicomponent fiber available from CHISSO Corporation, Osaka, Japan. In this particular bicomponent fiber, the polypropylene forms the core and the polyethylene forms the sheath of the fiber. Other fiber orientations are possible, such as multi-lobe, side-by-side, end-to-end, or the like.
Backsheet 40 is impermeable to liquids and is preferably manufactured from a thin plastic film, although other flexible liquid impermeable materials may also be used.
Backsheet 40 prevents the exudates absorbed and contained in absorbent structure 42 from wetting articles which contact training pant lO, such as bed sheets and clothing. A
21 ~J 2 ~ 7 suitable liquid impermeable backsheet 40 is a l.0 mil ~ polyethylene film obtainable from Edison Plastics Company of South Plainfield, New Jersey. Backsheet 40 can be embossed and/or matte-finished to provide a more clothlike appearance.
Furthermore, backsheet 40 can permit vapors to escape from absorbent structure 42, while still preventing exudates from passing through backsheet 40. A suitable "breathable"
material that permits vapors to escape from absorbent structure 42, while preventing liquid exudates from passing through backsheet 40, is a material composed of a microporous polymer film or a nonwoven fabric that has been coated or otherwise treated to impart a desired level of liquid impermeability. A suitable microporous film is a PMP-l film material, which is available from Mitsui Toatsu Chemicals, Inc., Tokyo, Japan, or an XK0-8044 polyolefin film available from 3M Company, Minneapolis, Minnesota.
Backsheet 40 and topsheet 38 are desirably congruent, i.e., of the same size and shape. If desired or nec~ss~ry, either topsheet 38 or backsheet 40 can have a different size and/or shape from the other. Backsheet 40 is positioned on the side of absorbent structure 42 opposite from topsheet 38, and is preferably attached to absorbent structure 42 by any suitable means well known in the art. For example, backsheet 40 may be secured to absorbent structure 42 by a uniform continuous layer of adhesive, a patterned layer of adhesive, or an array of separate lines or spots of adhesive. Suitable adhesives can be obtained from Findley Adhesives, Inc., Wauwatosa, 21 qG2~7 Wisconsin, and can be applied in any manner well known in the art.
Absorbent structure 42 can be any structure which is generally compressible, conformable, nonirritating to the child's skin, and capable of absorbing and retaining liquids and certain body exudates. Absorbent structure 42 can be manufactured in a wide variety of sizes and shapes, and from a wide variety of liquid absorbent materials commonly used in the art. For example, absorbent structure 42 can comprise pulp fluff, superabsorbent material, or a combination thereof. If in combination, the pulp fluff and the superabsorbent material can be blended together, or comprise discrete layers of fluff and discrete layers of superabsorbent material. Various types of wettable, hydrophilic fibrous material include naturally occurring organic fibers composed of intrinsically wettable material, such as cellulosic fibers; synthetic fibers composed of cellulose or cellulose derivatives, such as rayon fibers;
inorganic fibers composed of an inherently wettable material, such as glass fibers; and synthetic fibers composed of a nonwettable, thermoplastic polymer, such as polypropylene fibers, which have been hydrophilized by appropriate means.
- The fibers may be hydrophilized, for example, by treatment with silica, treatment with a material which has a suitable hydrophilic moiety, or the like.
Suitable superabsorbent materials may be organic or inorganic. Suitable inorganic superabsorbent materials 2i 9~;'87 include, by way of example, absorbent clays and silica gels.
Suitable organic superabsorbent materials include natural materials, such as pectin and peat moss, as well as synthetic materials, such as synthetic hydrogel polymers. Suitable superabsorbent materials are available from various commercial vendors, such as Dow Chemical Company, Hoechst-Celanese Corporation, and Allied Colloids, Inc. Typically, a superabsorbent material is capable of absorbing at least about 15 times its weight in water, and desirably is capable of absorbing more than about 25 times its weight in water.
In one embodiment, absorbent structure 42 is generally rectangular in shape, and comprises a blend of wood pulp fluff and superabsorbent material. One preferred type of pulp fluff is identified with the trade designation CR1654, available from Kimberly-Clark Corporation, Neenah, Wisconsin, and is a bleached, highly absorbent sulfate wood pulp cont~;ning primarily soft wood fibers. The fluff and superabsorbent material in absorbent structure 42 are present in a ratio Or about 9 grams to about 20 grams fluff to about 7 grams to about 14 grams superabsorbent material. The absorbent structure 42 has a density within the range of about 0.10 grams per cubic centimeter to about 0.35 grams per cubic centimeter. The absorbent structure 42 may or may not be wrapped or encompassed by a suitable tissue wrap that maintains the integrity and/or shape of the absorbent structure 42.
2 1 qo2~,7 For purposes of description herein, topsheet 38 and backsheet - 40 are of the same size and shape, and as viewed in Fig. 2, define a pant front edge 44, a pant back edge 46, and a pair of leg cutouts-48, which form leg openings 26 in the finished product, as illustrated by training pant 10 in Fig. 1.
A containment flap S0 is disposed on each side of absorbent structure 42. As illustrated in Fig. 2, each containment flap 50 includes a proximal edge 52, a distal edge 54, and a flap elastic 56 elastically associated in each distal edge 54. Each proximal edge 52 of a containment flap 50 is adhesively attached to topsheet 38 just slightly spaced apart from an absorbent side edge 58. Each flap elastic 56 is adhesively joined in a stretched condition to a respective distal edge 54, in a manner well known in the art. The respective ends of each containment flap 50 are coincident with pant front edge 44 and pant back edge 46, although this is not a necessary requirement.
Containment flaps 50 are, like topsheet 38 and backsheet 40, made of a suitable flexible material. As used herein, the term "flexible~ refers to materials which are compliant and will readily conform to the general shape~and contours of the child's body. Each flap elastic 56 can be a single or 2~ multiple ribbon or strand of suitable elastic material, which when joined in a stretched manner to a respective containment ' flap 50, will contract a distal edge 54 sufficiently away from topsheet 38 in order to form a channel or pocket between a containment flap 50 and topsheet 38, thereby permitting the 21 90~S7 retention of body exudates. Containment flaps s0 can be manufactured from a wide variety of materials such as polypropylene, polyester, rayon, nylon, foams, plastic films, elastic films, and the like. Various manufacturing techniques can be used to make containment flaps 50, such that they may be woven, nonwoven, spunbond, carded, or the like. Containment flaps 50 may also be made of the same material as that of which topsheet 38 is made.
Flap elastics 56 can be made of any suitable elastic material, and one suitable such material and construction is a plurality of strands of LYCRA~ 940 decitex that are joined at their ends to respective distal edges 54 while at an elongation of about 300 percent. Each individual strand is spaced from an adjacent strand by about 3 millimeters. These types of elastic strands can be obtained from E.I. DuPont de Nemours Company, Wilmington, Delaware. Other suitable elastic materials include natural rubber, synthetic rubber, or thermoplastic elastomeric polymers. These elastic materials may also be heat-elasticizable, and can be single or multiple ribbons of elastic material.
Other constructions of suitable containment flaps are described in U.S. Patent No. 4,704,116 issued November 3, 1987 to Enloe.
~s illustrated in Fig. 2, pant body 12 is in a partially disassembled, stretched flat condition, and as previously 21 ~02S7 mentioned includes front panel 14, back panel 16, and crotch panel 18. The total product, or pant, length is that length of pant body 12 in Fig. 2 measured between pant front edge 44 and pant back edge 46 in a vertical direction. By "vertical direction" is meant a top-to-bottom or bottom-to-top direction with respect to Fig. 2. Similarly, the term "horizontal direction" re~ers to a direction perpendicular to the vertical direction. Generally speaking, each of the panel lengths, that is front panel length 60, crotch panel length 62, back panel length 64, will have a length approximately 1/3 the total product length measured between pant front edge 44 and pant back edge 46.
In Fig. 2, front panel 14 comprises a front central section 66 and a pair of elastic front side sections 68, 70 having respective front side edges 72, 74. Similarly, back panel 16 comprises a back central section 76 and a pair of elastic back side sections 78, 80 having respective back side edges 82, 84. During the manufacturing process, pant body 12 is folded to substantially align front side edge 72 with back side edge 82, and front side edge 74 to back side edge 84.
Thereafter, these aligned edges are suitably joined together, such as by ultrasonic bonding, in order to form side seams 20 (Fig. 1). One method for aligning and bonding a folded article is described in U.S. Patent No. 5,046,272 issued September 10, 1991 to Vogt et al.
~1902~7 Prior to the folding and bonding to form side seams 20, a pair of leg elastic members 86 are suitably joined to pant body 12 at least at crotch panel 18. Each leg elastic member 86 can be any suitable construction well known in the art.
One suitable construction is that described in U.S. Patent No. 4,940,464 issued July 10, 1990 to VanGompel et al.
Another suitable construction for a leg elastic member 86 is a stretch bonded laminate comprising any suitable material having elastic properties. Examples of such suitable elastic materials include films or layers of natural rubber, synthetic rubber, or thermoplastic elastomeric polymers.
These materials can be arranged or manufactured as panels, or as single or multiple threads, filaments or ribbons. The materials may also be heat-elasticizable. The elastic materials of which flap elastics 56 are made may also be utilized in leg elastic members 86. Each leg elastic member 86, as a stretch bonded laminate, comprises at least one gatherable layer and one elastic layer or multiple threads of elastic material. As used throughout this description of the invention, the term "elastic" refers to that property of a material or composite or laminate that causes it to recover its original size and shape after removal of a force causing the deformation, and is expressed as a percent. The term "join", "joining", or variations thereof, when used in describing the relationship between two or more elements, means that the elements can be connected together in any suitable manner, s~ch as by heat sealing, ultrasonic bonding, 2 i 9~87 thermal bonding, adhesives, stitching, or the like; these elements can be joined directly together, or may have one or more elements interposed between them, all of which are connected together. Finally, the phrase "elastically joined", or variations thereof, generally describes the joining of an elastic member to a non-elastic member such that the two joined members exhibit elasticity or elastic properties. A suitable stretch bonded laminate construction for use as a leg elastic member 86 comprises two gatherable layers of spunbond polypropylene having a basis weight of about 14 grams per square meter (gsm) with a layer of meltblown elastic material having a basis weight of about 16 gsm therebetween. The layer of elastic material is stretched, the two layers of polypropylene are then joined to the stretched elastic layer, and upon relaxing the layers, the polypropylene layers are gathered by the elastic layer.
Continuing to refer to Fig. 2, elastic front side section 68 and elastic front side section 70 have the same size and shape, and are similarly constructed with the same materials.
Furthermore, elastic front side sections 68, 70 can be separate elastic structures suitably joined to front central section 66, such as that described in U.S. Patent No.
4,940,464 issued July lO, l990 to VanGompel, the contents of which are incorporated by reference herein. In this embodiment, each elastic front side section 68, 70 is a stretch bonded laminate made of any suitable materials, such as those identified in the aforementioned U.S. 4,940,464. In this specific construction, elastic front side section 68 has 21 qa,~at7 -a front edge coincident with pant front edge 44, a side edge - coincident with front side edge 72, and an inner edge so.
Similarly, elastic front side section 70 has a front edge coincident with pant front edge 44, a side edge coincident with front side edge 74, and an inner edge 92.
Similarly, elastic back side section 78 is constructed to have a back edge coincident with pant back edge 46, a side edge coincident with back side edge 82, and an inner edge 94.
Elastic back side section 80 also is constructed to have a back edge coincident with pant back edge 46, a side edge coincident with back side edge 84, and an inner edge 96.
Elastic back side sections 78, 80 can also be separate : elastic structures suitably joined to back central section 76, in a manner similar to that described above for joining : elastic front side sections 68, 70 to front central section 66.
.
In the above description of pant body 12, the gatherable layers of the stretch bonded laminate can be selected from materials that are compatible as portions of either liquid permeable topsheet 38 or liquid impermeable backsheet 40.
For example, the outermost gatherable layer can be liquid impermeable and gatherable, while the innermost gatherable layer can be liquid permeable and gatherable.
To this point in the description, dimensions have not been described for the product or any components thereof.
Hereafter, desired dimensions will be provided, and these dimensions can be determined by the following described - procedure.
- TEST PROCEDURE
EOUIPMENT AND MATERIALS
1. A suitable lightbox 156 (Fig. 7), at least 18 inches wide x 24 inches high, such as catalog number 3670S-052 available from VWR Scientific, 600 C Corporate Court, South Plainfield, NJ 07080. The lightbox is mounted vertically.
2. Two clamps 158, such as Hunt/Boston brand Bulldog Clips HUN02004, available from BT Publix Office Products, Inc., 700 West Chicago Avenue, Chicago, IL 60610, are mounted about 6 inches apart, near the top of the - lightbox 156, as shown in Figure 7.
3. Two clamps 160 (the same type as described above) with weights 162 attached, each weighing 500 + 5 grams total weight.
4. A rigid ruler having a scale in millimeters, such as No. C636 steel rule, available from the L. S. Starrett Co., Athol, Mass.
5. A fine point pen or other marking device.
-21 902~'7 TESTING PROCEDURE
l. Cut the training pant parallel to each side seam bond, on the front panel side.
5 2. Hang the pant vertically, using the clamps, on the lightbox, with the front end of the pant facing downwardly and with the backsheet facing toward the tester. In vertically hanging the pant, the pant should be gently stretched in the horizontal direction in order to flatten the pant sufficiently against the lightbox. The leg elastic members must be centered below the top clamps. Care should be taken to ensure that the clamps are not attached to the absorbent structure. Straighten and extend the pant by gently running the fingers down the sides of the leg elastic members.
3. Attach the weights to the pant waist area, making sure they are not attached to the absorbent structure.
Again, the leg elastic members must be centered between the bottom clamps. Then gently lower the weights, and verify that the front end waist area is completely stretched and the weights are hanging freely. Assure that the pant is extended by gently running the fingers down the sides of the leg elastic members.
4. Thereafter, length (i.e., vertical) dimensions and width (i.e., horizontal) dimensions can be made using the rigid ruler and fine point pen.
21 ~02~
- Referring now to Figs. 1-3, elastic waist barrier 34 generally surrounds or circumscribes waist opening 24 tFig.
1) and, for ease of manufacture, is joined to pant body 12 in two separate elements, as illustrated in Fig. 2. In Fig. 2, the uppermost elastic waist barrier 34 has a pair of opposed side edges 98, 100 and the lowermost elastic waist barrier 34 has opposed side edges 102, 104. During the folding and bonding steps of the manufacturing process for disposable absorbent training pant 10, side edges 98, 102 and side edges 100, 104 are bonded together desirably during the formation of and with side seams 20.
Although Fig. 2 illustrates an uppermost and lowermost elastic waist barrier 34, the present invention contemplates an elastic waist barrier 34 only in front panel 14 or back panel 16. Since the present invention primarily focuses on waste containment when the child is in the recumbent position, the elastic waist barrier 34 in back panel 16 can be eliminated. Since the design and construction of an elastic waist barrier 34 in back panel 16 can be identical to that in front panel 14, a description only of an elastic waist barrier 34 in front panel 14 will be made.
Elastic waist barrier 34 can be designed and constructed of any suitable elastic material known in the art. Examples of such materials are described in U.S. Patents No. 4,940,464 and 5,246,433. Other examples of various constructions of a suitable elastic waist barrier 34 are described in U.S.
~ 1 9~&7 Patent No. 4,652,487 issued March 24, 1987 to Morman, In one embodiment, elastic waist barrier 34 is a stretch bonded laminate comprising three layers of material, in which at least the center layer has elastic properties. For example, with reference to Fig. 4, a first gatherable layer 106 and a second gatherable layer 108 have situated therebetween a means for elasticizing the layers 106, 108.
The means for elasticizing can be, by way of example, an elastic layer 110 suitably joined when in a stretched condition to gatherable layers 106, 108. Methods of joining layers 106, 108 to a stretched elastic layer 110 include ultrasonic bonding, thermal bonding, point bonding, adhesive bonding, or the like. In choosing a particular means for bonding the elastic layer 110 to the gatherable layers 106, 108, care must be taken to ensure that the bonding does not unnecessarily inhibit the elastic characteristics of elastic layer 110. The choice of bonding method and apparatus will depend in major part upon the types of materials chosen, and the desired elasticity of the stretch bonded laminate.
It is desirable that at least one of the layers is liquid impermeable, and desirably that layer is the middle or elastic layer 110. This permits first gatherable layer 106 and second gatherable layer 108 to be made out of appropriate fibrous materials that give a clothlike touch and feel to the child's body. Examples of the materials of which gatherable layers 106, 108 are described in the aforementioned 21 ~02S7 U.S. patents. In one embodiment, first ~ gatherable layer 106 and second gatherable layer 108 are spunbond polypropylene composed of about 2.0 to about 3.0 denier fibers, and have a basis weight of about 24 gsm and a density of about 0.06 gm/cc. For purposes of simplicity in manufacturing, both first and second gatherable layers 106, 108 can be made of the same material and have the same basis weights. However, if desired, layers 106, 108 can be made of different materials, the same material but with different densities or basis weights, or other desired constructions.
In another embodiment, first and second gatherable layers 106, 108 can be liquid impermeable. The term "liquid impermeable" when used in describing a laminate, such as this one, means that liquid will not pass through the laminate, under ordinary conditions of use, in a direction generally perpendicular to the plane of the laminate at the point of liquid contact. Liquid may spread or be wicked parallel to the plane of a layer, such as a layer 106, 108, but this is not considered to be within the meaning of "liquid impermeable" when used with reference to a laminate.
In still another embodiment, stretched elastic strands are adhesively joined between two layers of spunbond polypropylene. It has been observed in some configurations that a liquid resistant laminate is achieved by adhesively laminating these liquid permeable, hydrophobic layers together, without the use of any surfactant treatment. In this embodiment, the term "liquid resistant" refers to 21 932~7 ~ retarding liquid penetration through a layer, or layers, for a sufficient period of time to allow the absorbent structure to absorb the liquid.
A particularly desirable method of manufacturing the waist barrier 34 includes (a) forming a meltblown elastomeric web comprised of a suitable elastomer, (b) elongating the meltblown elastomeric web to about 200 % beyond its relaxed length, (c) thermally point bonding spunbond polypropylene webs to the meltblown elastomeric web, and (d) allowing the meltblown elastomeric web to relax and the spunbond polypropylene webs to gather. The laminate is then slit to the desired dimension to produce an elastic waist barrier 34 for use in an absorbent product, such as training pant 10 (Fig. 1).
In Fig. 5, there is illustrated an alternate elastic waist barrier 112 comprising a gatherable layer 114, a flexible liquid impermeable layer 116, and a plurality of elastic strands 118 joined, while in a stretched condition, to both gatherable layer 114 and liquid impermeable layer 116 by a suitable spray adhesive 120. Gatherable layer 114 can be made of the same or different materials as gatherable layers 106, 108, and flexible liquid impermeable layer 116 can be a blown polyethylene film having a thickness of about 0.010 millimeter + about 0.001 millimeter, such as an XSF-367 film, available from Consolidated Thermoplastics located in Chippewa Falls, Wisconsin, or a 0.009 millimeter + about 0.001 millimeter stretch-thinned film such as XP 1024A, - ~ t~'j q~287 available from Edison Plastics, located in Macalester, Oklahoma. The spray adhesive 120 can be applied in any suitable manner well known in the art. A particularly desirable method of application uses a rubber based hot melt elastic adhesive such as H2096 available from Findley Adhesives, located in Wauwatosa, Wisconsin, and melt sprayed at about 6 grams per square meter.
With reference now to Fig. 6, another alternate elastic waist barrier 122 is illustrated comprising a liquid impermeable elastic layer 124. Elastic layer 124 can be made of those suitable elastic materials in the aforementioned and incorporated U.S. patents, and can be either inherently liquid impermeable or treated to be liquid impermeable by the addition of a suitable substance, such as a surfactant.
Referring now to Fig. 2, elastic waist barrier 34 is illustrated in its fully stretched condition, after being suitably joined to waist peripheral region 28 of pant body 12. Generally, waist peripheral region 28 has a vertical length between about 2 centimeters to about 6 centimeters, as measured from pant front edge 44. As illustrated in Fig. 3, pant front edge 44 is defined by the three edges of elastic waist barrier 34, topsheet 38, and backsheet 40. These edges will generally be coincident with each other as a result of the cutting step in the manufacturing process. However, if one of the edges of elastic waist barrier 34, topsheet 38, or backsheet 40, as illustrated in Fig. 3, are not coincident with the other edges, then the outermost edge, i.e., the edge 21 qO287 extending furthest to the right in Fig. 3, defines pant front edge 44.
Elastic waist barrier 34 further includes a free edge 126, which is spaced from topsheet 38 due to the elastic properties of elastic waist barrier 34, as illustrated in Fig. 3, thereby forming trough 36. The vertical, or length, dimension of elastic waist barrier 34 (Fig. 2) is desirably about 15 millimeters or more, and generally needs not exceed about 6 centimeters.
Continuing to refer primarily to Fig. 2, elastic waist barrier 34 is divided into three portions that are joined to waist peripheral region 28. Specifically, an elastic central portion 128 is joined to waist peripheral region 28 by a generally horizontal, generally continuous, liquid barrier bond line 130: and a pair of elastic side portions 132 are suitably joined to waist peripheral region 28 by a plurality of intermittent bonds 134. Generally, continuous bond line 130 will extend beyond, or past, absorbent side edges 58. A
pair of generally vertical bond lines 136 extend downwardly from opposite ends of continuous bond line 130 to the free edge 126 of elastic waist barrier 34. As illustrated in Fig.
2, vertical bond lines 136 are continuous, liquid barriers, similar to continuous bond line 130. If desired, vertical bond lines 136 can be intermittent, similar to intermittent bonds 134. Vertical bond lines 136 desirably extend downwardly from continuous bond line 130 between a respective absorbent side edge 58 and a respective inner edge 90, 92 of - - -- - -21 902~7 front elastic side sections 68, 70. An advantage of vertical bond lines 136 being generally continuous, liquid barriers is that they form with continuous bond line 130 a generally U-chApe~ trough 36 for containing waste material.
Bond lines 130, 136 and intermittent bonds 134 are constructed when pant body 12 is in the flat state with elastic waist barrier 34 stretched or extended to the desired elongation. The term "elongation" means the ratio of the extension of a material to the length of the material prior to the extension, expressed as a percent, and is represented by the following formula:
Extended Length - Original Length x 100%.
Original Length Bond lines 130, 136, as well as intermittent bonds 134, can be constructed in any suitable manner well known in the art, such as by rotary ultrasonic bonding.
In elastically joining waist barrier 34 to waist peripheral region 28, care should to be taken in the extension of waist barrier 34. For example, if front panel 14 is formed or manufactured without elastic front side sections 68, 70, then waist barrier 34 can be extended a uniform elongation throughout the length thereof. However, if front panel 14 is provided with elastic front side sections 68, 70, then elastic side portions 132 of elastic waist barrier 34 may need to be joined in a relaxed state. Elastic side portions 21 902~7 132 should have an elasticity equal to or greater than that of elastic front side sections 68, 70, so that the joining of elastic side portions 132 desirably will not substantially inhibit the elastic properties of elastic front side sections 68, 70. Elastic central portion 128 can be separately stretched or extended, and thereafter joined to waist peripheral region 28 by continuous bond line 130 and, if desired, vertical bond lines 136.
One of the advantages of the present invention is the choice of method in joining elastic side portions 132 and elastic central portion 128 to waist peripheral region 28. By selectively varying the extensions of these portions, different elasticities can be provided along waist peripheral region 28. For example, elastic side portions 132 could have an extension greater than, the same as, or less than that of elastic central portion 128, in order to provide differential elasticity about the waist opening 24 of training pant 10 (Fig. 1). This is particularly advantageous when segments of waist peripheral region 28 have different basis weights, are composed of different layers of material, or the like.
Turning now to Fig. 3, absorbent structure 42 further includes an absorbent front edge 138, which is substantially straight or linear, as viewed in a left-to-right direction in Fig. 2, but which in some cases can be non-linear. In this latter case of a non-linear front edge l38, the positional relationship between a non-linear front edge 138 and a straight bond line 130 (Fig. 2) is measured from that point ;~1 90287 on the non-linear front edge 138 that is the closest to bond line 130. In some constructions, a tissue wrap encompassing or wrapping the absorbent material of absorbent structure 42 may extend beyond the end of front edge 138. For purposes of this part of the description, such tissue wraps are not considered to be part of the absorbent structure 42. While in some embodiments the absorbent front edge 138 is abrupt, in other embodiments absorbent structure 42 may have a non-abrupt front edge 138, such as when the absorbent structure 42 tapers in thickness towards front edge 138, is comprised of discrete pockets of absorbent material, or the like. In the latter case, the front edge 138 is defined as the line where the absorbent structure 42 has a basis weight of about 60 grams per square meter. The basis weight of the absorbent structure 42 near the front edge 138 may be determined by the following procedure:
A S millimeter by 50 millimeter rectangle of absorbent material is cut and removed from absorbent structure 42, along with any tissue wrap, along a line approximately parallel to bond line 130. If the mass of this rectangle is 15 milligrams or greater, then it is considered to be part of the absorbent structure 42. If the mass is less than 15 milligrams, it is not considered to be part of the absorbent structure 42 for purposes of identifying front edge 138.
If absorbent front edge 138 has a curvilinear, i.e., not a straight or linear, edge, then continuous bond line 130 can Zl 90~87 be curvilinearly formed generally parallel to the curvilinear front edge 138. In this case, the positional relationship between absorbent front edge 138 and continuous bond line 130 can be taken at any desired location between these two elements.
Referring to Fig. 3, continuous bond line 130 includes a bond line inner surface 140, and a bond line outer surface 142.
As illustrated, bond line 130 has a cross section that is generally rectangular in shape, and thus surfaces 140, 142 are generally planar. However, where the cross section of continuous bond line 130 is of a shape different than a generally rectangular shape, such as square, oval, flat, or the like, positional relationships between absorbent front edge 138 and bond line inner surface 140 are taken at that - point or line of inner surface 140 that is closest to absorbent front edge 138.
Although the positional relationship between absorbent front edge 138 and continuous bond line 130 has been made in general terms so far, this relationship is one of the unique features of the present invention. Fig. 3 illustrates an overall first length 144 comprising an end seal length 146, a bond seal length 148, and a free end length 150. Overall first length 144 is measured between absorbent front edge 138 and pant front edge 44. End seal length 146 is measured between absorbent front edge 138 and bond line inner surface 140. Bond seal length 148 is measured between bond line inner surface 140 and bond line outer surface 142. Free end 2 1 9~287 length 150 is measured between bond line outer surface 142 and pant front edge 44. Of these three lengths comprising overall first length 144, the most significant are end seal length 146 and bond seal length 148.
Another significant feature of the present invention is the positional relationship between absorbent structure 42 and elastic waist barrier 34. As illustrated in Figures 2 and 3, at least the front portion of absorbent structure 42 is encompassed or received between elastic waist barrier 34 and liquid impermeable backsheet 40, thereby surrounding that portion of absorbent structure 42 in a substantially liquid impermeable pocket or trough 36. This is very important to the present invention in improving waste containment when the child is in the recumbent position.
These positional relationships described above are important to the present invention, and particularly in providing optimum performance when the child is in the recumbent position. A particular range of lengths, as measured in a left-to-right direction in Fig. 3, for end seal length 146 is about 2 centimeters or less, and a more particular range is about 1 centimeter or less. For bond seal length 148, a particular range of lengths is between about 2 to about 8 millimeters, and a more particular range is between about 3 to about 6 millimeters. With respect to the length of elastic waist barrier 34 between bond line inner surface 140 and free edge 126, a particular range is between about 2 21 90~7 centimeters to about 6 centimeters, and a more particular range is between about 2 centimeters to about 3 centimeters.
Several advantages result from the above described features of the present invention. One is that the elastic waist barrier 34 is uniquely beneficial to boys in the potty or toilet training stage, particularly because of the penis frequently being pointed toward the waist of the pant during urination, and the tendency for the waist of the pant to slide or move down under the weight of the wet pant, thereby causing a gap or opening between the waist of the training pant and the body of the child. A net effect of these two factors is a reduction in the distance between the waist of the pant and the origin or source of the urination. The reduction in this distance increases the probability of leakage at the waist, and particularly so since there is less absorbent material in this area of the pant. Elastic waist barrier 34 mitigates this situation in several ways. The freedom of movement of elastic waist barrier 34 enables it to stay in contact with the body of the child, since its elastic properties cause at least the free edge 126 (Fig. 3) to move upwardly or away from topsheet 38 into a position against the body of the child. This, in effect, creates a gasket or seal that counteracts any gapping at the waist. This movement of elastic waist barrier 34 away from topsheet 38 creates trough 36 for containing waste material. Further, by spacing absorbent front edge 138 from continuous bond line 130 within the prescribed ranges, absorbent structure 42 can be placed or positioned nearer to waist opening 24, i.e., effectively 21 90~1 higher up on the body of the child. This is advantageous in providing additional absorbent capacity near waist opening 24.
Another advantage provided by the present invention is two separate zones of elasticity represented by a zone 152 (Fig.
3) defined between free edge 126 and bond line inner surface 140, and a zone 154 defined by free end length 150 measured between bond line outer surface 142 and pant front edge 44.
By varying the dimension of zones 152, 154, elastic waist barrier 34 can provide distinctly different elastic characteristics to waist peripheral region 28 (Fig. 1) of training pant 10. For example, if the means for elasticizing is the elastic layer 110 of Fig. 4, different elasticities can be provided to zones 152, 154 by selective placement of the bond line 130 between front edge 126 and pant front edge 44.
In the embodiment in Fig. 5, different elastic characteristics can be provided to zones 152, 154 by selecting the individual elastic strands with different elastic characteristics. For example, those elastic strands in 118 in zone 152 could have greater elasticity than those strands 118 in zone 154, or vice versa. In fact, even within the individual zones 152, 154, the elastic characteristics of strands 118 can be varied as desired.
Still another advantageous feature of the present invention is the measure of the resistance of elastic waste barrier 34 2 1 902~7 to penetration by water. In this instance, elastic waist barrier 34 can be made of a material or materials, and have a construction capable of supporting a hydrohead of at least about 30 centimeters or more of water. A suitable method for determining the resistance of elastic waist barrier 34 to liquid penetration is INDA St~ rd Test: IST 80.4 (95).
This desired hydrohead value of at least about 30 centimeters or more of water provides sufficient resistance to liquid penetration to allow trough 36 to contain waste material for an adequate period of time to allow absorbent structure 42 to absorb the waste.
As described, the present invention provides improved containment at the front waist area of a disposable training pant when the child is in a recumbent position, and particularly for boys. This improvement results from elastic waist barrier 34 providing an improved fit and seal at the waist, due in major part to the different zones 152, 154 of elasticity. These zones 152, 154 not only provide a snugger fit, but also cause elastic waist barrier 34 to remain in contact with the child's body to counteract any gapping at the waist. Furthermore, since absorbent structure 42 does not inhibit the elasticity of elastic waist barrier 34, the absorbent front edge 138 can be moved closer to the pant front edge 44, thereby resulting in increased absorbent capacity at the front waist area.
2 1 90~7 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 fall within the limits of the appended claims.
-21 902~'7 TESTING PROCEDURE
l. Cut the training pant parallel to each side seam bond, on the front panel side.
5 2. Hang the pant vertically, using the clamps, on the lightbox, with the front end of the pant facing downwardly and with the backsheet facing toward the tester. In vertically hanging the pant, the pant should be gently stretched in the horizontal direction in order to flatten the pant sufficiently against the lightbox. The leg elastic members must be centered below the top clamps. Care should be taken to ensure that the clamps are not attached to the absorbent structure. Straighten and extend the pant by gently running the fingers down the sides of the leg elastic members.
3. Attach the weights to the pant waist area, making sure they are not attached to the absorbent structure.
Again, the leg elastic members must be centered between the bottom clamps. Then gently lower the weights, and verify that the front end waist area is completely stretched and the weights are hanging freely. Assure that the pant is extended by gently running the fingers down the sides of the leg elastic members.
4. Thereafter, length (i.e., vertical) dimensions and width (i.e., horizontal) dimensions can be made using the rigid ruler and fine point pen.
21 ~02~
- Referring now to Figs. 1-3, elastic waist barrier 34 generally surrounds or circumscribes waist opening 24 tFig.
1) and, for ease of manufacture, is joined to pant body 12 in two separate elements, as illustrated in Fig. 2. In Fig. 2, the uppermost elastic waist barrier 34 has a pair of opposed side edges 98, 100 and the lowermost elastic waist barrier 34 has opposed side edges 102, 104. During the folding and bonding steps of the manufacturing process for disposable absorbent training pant 10, side edges 98, 102 and side edges 100, 104 are bonded together desirably during the formation of and with side seams 20.
Although Fig. 2 illustrates an uppermost and lowermost elastic waist barrier 34, the present invention contemplates an elastic waist barrier 34 only in front panel 14 or back panel 16. Since the present invention primarily focuses on waste containment when the child is in the recumbent position, the elastic waist barrier 34 in back panel 16 can be eliminated. Since the design and construction of an elastic waist barrier 34 in back panel 16 can be identical to that in front panel 14, a description only of an elastic waist barrier 34 in front panel 14 will be made.
Elastic waist barrier 34 can be designed and constructed of any suitable elastic material known in the art. Examples of such materials are described in U.S. Patents No. 4,940,464 and 5,246,433. Other examples of various constructions of a suitable elastic waist barrier 34 are described in U.S.
~ 1 9~&7 Patent No. 4,652,487 issued March 24, 1987 to Morman, In one embodiment, elastic waist barrier 34 is a stretch bonded laminate comprising three layers of material, in which at least the center layer has elastic properties. For example, with reference to Fig. 4, a first gatherable layer 106 and a second gatherable layer 108 have situated therebetween a means for elasticizing the layers 106, 108.
The means for elasticizing can be, by way of example, an elastic layer 110 suitably joined when in a stretched condition to gatherable layers 106, 108. Methods of joining layers 106, 108 to a stretched elastic layer 110 include ultrasonic bonding, thermal bonding, point bonding, adhesive bonding, or the like. In choosing a particular means for bonding the elastic layer 110 to the gatherable layers 106, 108, care must be taken to ensure that the bonding does not unnecessarily inhibit the elastic characteristics of elastic layer 110. The choice of bonding method and apparatus will depend in major part upon the types of materials chosen, and the desired elasticity of the stretch bonded laminate.
It is desirable that at least one of the layers is liquid impermeable, and desirably that layer is the middle or elastic layer 110. This permits first gatherable layer 106 and second gatherable layer 108 to be made out of appropriate fibrous materials that give a clothlike touch and feel to the child's body. Examples of the materials of which gatherable layers 106, 108 are described in the aforementioned 21 ~02S7 U.S. patents. In one embodiment, first ~ gatherable layer 106 and second gatherable layer 108 are spunbond polypropylene composed of about 2.0 to about 3.0 denier fibers, and have a basis weight of about 24 gsm and a density of about 0.06 gm/cc. For purposes of simplicity in manufacturing, both first and second gatherable layers 106, 108 can be made of the same material and have the same basis weights. However, if desired, layers 106, 108 can be made of different materials, the same material but with different densities or basis weights, or other desired constructions.
In another embodiment, first and second gatherable layers 106, 108 can be liquid impermeable. The term "liquid impermeable" when used in describing a laminate, such as this one, means that liquid will not pass through the laminate, under ordinary conditions of use, in a direction generally perpendicular to the plane of the laminate at the point of liquid contact. Liquid may spread or be wicked parallel to the plane of a layer, such as a layer 106, 108, but this is not considered to be within the meaning of "liquid impermeable" when used with reference to a laminate.
In still another embodiment, stretched elastic strands are adhesively joined between two layers of spunbond polypropylene. It has been observed in some configurations that a liquid resistant laminate is achieved by adhesively laminating these liquid permeable, hydrophobic layers together, without the use of any surfactant treatment. In this embodiment, the term "liquid resistant" refers to 21 932~7 ~ retarding liquid penetration through a layer, or layers, for a sufficient period of time to allow the absorbent structure to absorb the liquid.
A particularly desirable method of manufacturing the waist barrier 34 includes (a) forming a meltblown elastomeric web comprised of a suitable elastomer, (b) elongating the meltblown elastomeric web to about 200 % beyond its relaxed length, (c) thermally point bonding spunbond polypropylene webs to the meltblown elastomeric web, and (d) allowing the meltblown elastomeric web to relax and the spunbond polypropylene webs to gather. The laminate is then slit to the desired dimension to produce an elastic waist barrier 34 for use in an absorbent product, such as training pant 10 (Fig. 1).
In Fig. 5, there is illustrated an alternate elastic waist barrier 112 comprising a gatherable layer 114, a flexible liquid impermeable layer 116, and a plurality of elastic strands 118 joined, while in a stretched condition, to both gatherable layer 114 and liquid impermeable layer 116 by a suitable spray adhesive 120. Gatherable layer 114 can be made of the same or different materials as gatherable layers 106, 108, and flexible liquid impermeable layer 116 can be a blown polyethylene film having a thickness of about 0.010 millimeter + about 0.001 millimeter, such as an XSF-367 film, available from Consolidated Thermoplastics located in Chippewa Falls, Wisconsin, or a 0.009 millimeter + about 0.001 millimeter stretch-thinned film such as XP 1024A, - ~ t~'j q~287 available from Edison Plastics, located in Macalester, Oklahoma. The spray adhesive 120 can be applied in any suitable manner well known in the art. A particularly desirable method of application uses a rubber based hot melt elastic adhesive such as H2096 available from Findley Adhesives, located in Wauwatosa, Wisconsin, and melt sprayed at about 6 grams per square meter.
With reference now to Fig. 6, another alternate elastic waist barrier 122 is illustrated comprising a liquid impermeable elastic layer 124. Elastic layer 124 can be made of those suitable elastic materials in the aforementioned and incorporated U.S. patents, and can be either inherently liquid impermeable or treated to be liquid impermeable by the addition of a suitable substance, such as a surfactant.
Referring now to Fig. 2, elastic waist barrier 34 is illustrated in its fully stretched condition, after being suitably joined to waist peripheral region 28 of pant body 12. Generally, waist peripheral region 28 has a vertical length between about 2 centimeters to about 6 centimeters, as measured from pant front edge 44. As illustrated in Fig. 3, pant front edge 44 is defined by the three edges of elastic waist barrier 34, topsheet 38, and backsheet 40. These edges will generally be coincident with each other as a result of the cutting step in the manufacturing process. However, if one of the edges of elastic waist barrier 34, topsheet 38, or backsheet 40, as illustrated in Fig. 3, are not coincident with the other edges, then the outermost edge, i.e., the edge 21 qO287 extending furthest to the right in Fig. 3, defines pant front edge 44.
Elastic waist barrier 34 further includes a free edge 126, which is spaced from topsheet 38 due to the elastic properties of elastic waist barrier 34, as illustrated in Fig. 3, thereby forming trough 36. The vertical, or length, dimension of elastic waist barrier 34 (Fig. 2) is desirably about 15 millimeters or more, and generally needs not exceed about 6 centimeters.
Continuing to refer primarily to Fig. 2, elastic waist barrier 34 is divided into three portions that are joined to waist peripheral region 28. Specifically, an elastic central portion 128 is joined to waist peripheral region 28 by a generally horizontal, generally continuous, liquid barrier bond line 130: and a pair of elastic side portions 132 are suitably joined to waist peripheral region 28 by a plurality of intermittent bonds 134. Generally, continuous bond line 130 will extend beyond, or past, absorbent side edges 58. A
pair of generally vertical bond lines 136 extend downwardly from opposite ends of continuous bond line 130 to the free edge 126 of elastic waist barrier 34. As illustrated in Fig.
2, vertical bond lines 136 are continuous, liquid barriers, similar to continuous bond line 130. If desired, vertical bond lines 136 can be intermittent, similar to intermittent bonds 134. Vertical bond lines 136 desirably extend downwardly from continuous bond line 130 between a respective absorbent side edge 58 and a respective inner edge 90, 92 of - - -- - -21 902~7 front elastic side sections 68, 70. An advantage of vertical bond lines 136 being generally continuous, liquid barriers is that they form with continuous bond line 130 a generally U-chApe~ trough 36 for containing waste material.
Bond lines 130, 136 and intermittent bonds 134 are constructed when pant body 12 is in the flat state with elastic waist barrier 34 stretched or extended to the desired elongation. The term "elongation" means the ratio of the extension of a material to the length of the material prior to the extension, expressed as a percent, and is represented by the following formula:
Extended Length - Original Length x 100%.
Original Length Bond lines 130, 136, as well as intermittent bonds 134, can be constructed in any suitable manner well known in the art, such as by rotary ultrasonic bonding.
In elastically joining waist barrier 34 to waist peripheral region 28, care should to be taken in the extension of waist barrier 34. For example, if front panel 14 is formed or manufactured without elastic front side sections 68, 70, then waist barrier 34 can be extended a uniform elongation throughout the length thereof. However, if front panel 14 is provided with elastic front side sections 68, 70, then elastic side portions 132 of elastic waist barrier 34 may need to be joined in a relaxed state. Elastic side portions 21 902~7 132 should have an elasticity equal to or greater than that of elastic front side sections 68, 70, so that the joining of elastic side portions 132 desirably will not substantially inhibit the elastic properties of elastic front side sections 68, 70. Elastic central portion 128 can be separately stretched or extended, and thereafter joined to waist peripheral region 28 by continuous bond line 130 and, if desired, vertical bond lines 136.
One of the advantages of the present invention is the choice of method in joining elastic side portions 132 and elastic central portion 128 to waist peripheral region 28. By selectively varying the extensions of these portions, different elasticities can be provided along waist peripheral region 28. For example, elastic side portions 132 could have an extension greater than, the same as, or less than that of elastic central portion 128, in order to provide differential elasticity about the waist opening 24 of training pant 10 (Fig. 1). This is particularly advantageous when segments of waist peripheral region 28 have different basis weights, are composed of different layers of material, or the like.
Turning now to Fig. 3, absorbent structure 42 further includes an absorbent front edge 138, which is substantially straight or linear, as viewed in a left-to-right direction in Fig. 2, but which in some cases can be non-linear. In this latter case of a non-linear front edge l38, the positional relationship between a non-linear front edge 138 and a straight bond line 130 (Fig. 2) is measured from that point ;~1 90287 on the non-linear front edge 138 that is the closest to bond line 130. In some constructions, a tissue wrap encompassing or wrapping the absorbent material of absorbent structure 42 may extend beyond the end of front edge 138. For purposes of this part of the description, such tissue wraps are not considered to be part of the absorbent structure 42. While in some embodiments the absorbent front edge 138 is abrupt, in other embodiments absorbent structure 42 may have a non-abrupt front edge 138, such as when the absorbent structure 42 tapers in thickness towards front edge 138, is comprised of discrete pockets of absorbent material, or the like. In the latter case, the front edge 138 is defined as the line where the absorbent structure 42 has a basis weight of about 60 grams per square meter. The basis weight of the absorbent structure 42 near the front edge 138 may be determined by the following procedure:
A S millimeter by 50 millimeter rectangle of absorbent material is cut and removed from absorbent structure 42, along with any tissue wrap, along a line approximately parallel to bond line 130. If the mass of this rectangle is 15 milligrams or greater, then it is considered to be part of the absorbent structure 42. If the mass is less than 15 milligrams, it is not considered to be part of the absorbent structure 42 for purposes of identifying front edge 138.
If absorbent front edge 138 has a curvilinear, i.e., not a straight or linear, edge, then continuous bond line 130 can Zl 90~87 be curvilinearly formed generally parallel to the curvilinear front edge 138. In this case, the positional relationship between absorbent front edge 138 and continuous bond line 130 can be taken at any desired location between these two elements.
Referring to Fig. 3, continuous bond line 130 includes a bond line inner surface 140, and a bond line outer surface 142.
As illustrated, bond line 130 has a cross section that is generally rectangular in shape, and thus surfaces 140, 142 are generally planar. However, where the cross section of continuous bond line 130 is of a shape different than a generally rectangular shape, such as square, oval, flat, or the like, positional relationships between absorbent front edge 138 and bond line inner surface 140 are taken at that - point or line of inner surface 140 that is closest to absorbent front edge 138.
Although the positional relationship between absorbent front edge 138 and continuous bond line 130 has been made in general terms so far, this relationship is one of the unique features of the present invention. Fig. 3 illustrates an overall first length 144 comprising an end seal length 146, a bond seal length 148, and a free end length 150. Overall first length 144 is measured between absorbent front edge 138 and pant front edge 44. End seal length 146 is measured between absorbent front edge 138 and bond line inner surface 140. Bond seal length 148 is measured between bond line inner surface 140 and bond line outer surface 142. Free end 2 1 9~287 length 150 is measured between bond line outer surface 142 and pant front edge 44. Of these three lengths comprising overall first length 144, the most significant are end seal length 146 and bond seal length 148.
Another significant feature of the present invention is the positional relationship between absorbent structure 42 and elastic waist barrier 34. As illustrated in Figures 2 and 3, at least the front portion of absorbent structure 42 is encompassed or received between elastic waist barrier 34 and liquid impermeable backsheet 40, thereby surrounding that portion of absorbent structure 42 in a substantially liquid impermeable pocket or trough 36. This is very important to the present invention in improving waste containment when the child is in the recumbent position.
These positional relationships described above are important to the present invention, and particularly in providing optimum performance when the child is in the recumbent position. A particular range of lengths, as measured in a left-to-right direction in Fig. 3, for end seal length 146 is about 2 centimeters or less, and a more particular range is about 1 centimeter or less. For bond seal length 148, a particular range of lengths is between about 2 to about 8 millimeters, and a more particular range is between about 3 to about 6 millimeters. With respect to the length of elastic waist barrier 34 between bond line inner surface 140 and free edge 126, a particular range is between about 2 21 90~7 centimeters to about 6 centimeters, and a more particular range is between about 2 centimeters to about 3 centimeters.
Several advantages result from the above described features of the present invention. One is that the elastic waist barrier 34 is uniquely beneficial to boys in the potty or toilet training stage, particularly because of the penis frequently being pointed toward the waist of the pant during urination, and the tendency for the waist of the pant to slide or move down under the weight of the wet pant, thereby causing a gap or opening between the waist of the training pant and the body of the child. A net effect of these two factors is a reduction in the distance between the waist of the pant and the origin or source of the urination. The reduction in this distance increases the probability of leakage at the waist, and particularly so since there is less absorbent material in this area of the pant. Elastic waist barrier 34 mitigates this situation in several ways. The freedom of movement of elastic waist barrier 34 enables it to stay in contact with the body of the child, since its elastic properties cause at least the free edge 126 (Fig. 3) to move upwardly or away from topsheet 38 into a position against the body of the child. This, in effect, creates a gasket or seal that counteracts any gapping at the waist. This movement of elastic waist barrier 34 away from topsheet 38 creates trough 36 for containing waste material. Further, by spacing absorbent front edge 138 from continuous bond line 130 within the prescribed ranges, absorbent structure 42 can be placed or positioned nearer to waist opening 24, i.e., effectively 21 90~1 higher up on the body of the child. This is advantageous in providing additional absorbent capacity near waist opening 24.
Another advantage provided by the present invention is two separate zones of elasticity represented by a zone 152 (Fig.
3) defined between free edge 126 and bond line inner surface 140, and a zone 154 defined by free end length 150 measured between bond line outer surface 142 and pant front edge 44.
By varying the dimension of zones 152, 154, elastic waist barrier 34 can provide distinctly different elastic characteristics to waist peripheral region 28 (Fig. 1) of training pant 10. For example, if the means for elasticizing is the elastic layer 110 of Fig. 4, different elasticities can be provided to zones 152, 154 by selective placement of the bond line 130 between front edge 126 and pant front edge 44.
In the embodiment in Fig. 5, different elastic characteristics can be provided to zones 152, 154 by selecting the individual elastic strands with different elastic characteristics. For example, those elastic strands in 118 in zone 152 could have greater elasticity than those strands 118 in zone 154, or vice versa. In fact, even within the individual zones 152, 154, the elastic characteristics of strands 118 can be varied as desired.
Still another advantageous feature of the present invention is the measure of the resistance of elastic waste barrier 34 2 1 902~7 to penetration by water. In this instance, elastic waist barrier 34 can be made of a material or materials, and have a construction capable of supporting a hydrohead of at least about 30 centimeters or more of water. A suitable method for determining the resistance of elastic waist barrier 34 to liquid penetration is INDA St~ rd Test: IST 80.4 (95).
This desired hydrohead value of at least about 30 centimeters or more of water provides sufficient resistance to liquid penetration to allow trough 36 to contain waste material for an adequate period of time to allow absorbent structure 42 to absorb the waste.
As described, the present invention provides improved containment at the front waist area of a disposable training pant when the child is in a recumbent position, and particularly for boys. This improvement results from elastic waist barrier 34 providing an improved fit and seal at the waist, due in major part to the different zones 152, 154 of elasticity. These zones 152, 154 not only provide a snugger fit, but also cause elastic waist barrier 34 to remain in contact with the child's body to counteract any gapping at the waist. Furthermore, since absorbent structure 42 does not inhibit the elasticity of elastic waist barrier 34, the absorbent front edge 138 can be moved closer to the pant front edge 44, thereby resulting in increased absorbent capacity at the front waist area.
2 1 90~7 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 fall within the limits of the appended claims.
Claims (20)
1. A disposable absorbent training pant, comprising:
a three-dimensional pant body defining a pant interior, an interior surface, a waist opening, and a pair of leg openings, said pant body including a front panel, a crotch panel, a back panel, and an absorbent structure in said pant interior, a waist peripheral region having a waist peripheral edge generally circumscribing said waist opening, and an elastic waist barrier in said pant interior and being joined to said waist peripheral region near said waist peripheral edge thereof, said elastic waist barrier extending vertically downwardly from said waist peripheral edge to form a trough, said elastic waist barrier having a hydrohead value of at least about 30 centimeters or more of water to provide sufficient resistance to liquid penetration to allow adequate time for absorption by said absorbent structure.
a three-dimensional pant body defining a pant interior, an interior surface, a waist opening, and a pair of leg openings, said pant body including a front panel, a crotch panel, a back panel, and an absorbent structure in said pant interior, a waist peripheral region having a waist peripheral edge generally circumscribing said waist opening, and an elastic waist barrier in said pant interior and being joined to said waist peripheral region near said waist peripheral edge thereof, said elastic waist barrier extending vertically downwardly from said waist peripheral edge to form a trough, said elastic waist barrier having a hydrohead value of at least about 30 centimeters or more of water to provide sufficient resistance to liquid penetration to allow adequate time for absorption by said absorbent structure.
2. The pant of claim 1 wherein said absorbent structure includes a pair of absorbent side edges and an absorbent front edge, and wherein said elastic waist barrier is joined to said waist peripheral region by a generally horizontal liquid barrier bond line, said absorbent front edge being spaced from said generally horizontal liquid barrier bond line a distance less than about 2 centimeters.
3. The pant of claim 2 further comprising a pair of generally vertical liquid barrier bond lines extending from said generally horizontal liquid barrier bond line, and joining said elastic waist barrier to said waist peripheral region, one of said generally vertical liquid barrier bond lines being generally adjacent one of said absorbent side edges, and the other of said generally vertical liquid barrier bond lines being generally adjacent the other of said absorbent side edges, whereby said trough is formed in a generally U-shape with said absorbent front edge positioned thereunder.
4. The pant of claim 2 wherein said pant body further includes a generally liquid permeable topsheet, and a generally liquid impermeable backsheet, and wherein said generally horizontal liquid barrier bond line joins said topsheet, said backsheet, and said elastic waist barrier together.
5. The pant of claim 1 wherein said elastic waist barrier has a vertical dimension of about 15 millimeters or more.
6. A disposable absorbent training pant, comprising:
a front panel comprising a pair of elastic front side sections and a front central section between said elastic front side sections, a back panel comprising a pair of elastic back side sections and a back central section between said elastic back side sections, a crotch panel between said front panel and said back panel, an absorbent structure comprising an absorbent front edge and a pair of absorbent side edges, a pair of tearable, nonrefastenable side seams joining said elastic front side sections to said elastic back side sections to define a pant interior, a waist opening, and a pair of leg openings, an elastic waist barrier comprising a pair of elastic side portions, an elastic central portion between said elastic side portions, and opposite side edges, said elastic central portion being joined, while in a generally stretched condition, to said front central section of said front panel by a generally horizontal, continuous liquid barrier bond line, said elastic side portions being joined, while in a generally relaxed condition, to said elastic front side sections of said front panel, and a pair of generally vertical, continuous liquid barrier bond lines extending vertically downwardly from said generally horizontal, continuous liquid barrier bond line to form a trough.
a front panel comprising a pair of elastic front side sections and a front central section between said elastic front side sections, a back panel comprising a pair of elastic back side sections and a back central section between said elastic back side sections, a crotch panel between said front panel and said back panel, an absorbent structure comprising an absorbent front edge and a pair of absorbent side edges, a pair of tearable, nonrefastenable side seams joining said elastic front side sections to said elastic back side sections to define a pant interior, a waist opening, and a pair of leg openings, an elastic waist barrier comprising a pair of elastic side portions, an elastic central portion between said elastic side portions, and opposite side edges, said elastic central portion being joined, while in a generally stretched condition, to said front central section of said front panel by a generally horizontal, continuous liquid barrier bond line, said elastic side portions being joined, while in a generally relaxed condition, to said elastic front side sections of said front panel, and a pair of generally vertical, continuous liquid barrier bond lines extending vertically downwardly from said generally horizontal, continuous liquid barrier bond line to form a trough.
7. The pant of claim 6 wherein said elastic side portions of said elastic waist barrier are intermittently joined to said elastic front side sections.
8. The pant of claim 7 wherein said opposite side edges of said elastic waist barrier are respectively joined with said tearable, nonrefastenable side seams.
9. The pant of claim 8 wherein said absorbent front edge is positioned within said trough.
10. The pant of claim 9 wherein said elastic waist barrier has a hydrohead value of at least about 30 centimeters.
11. The pant of claim 10 wherein said absorbent front edge is spaced from an inner surface of said generally horizontal, continuous liquid barrier bond line a distance of about 2 centimeters or less.
12. The pant of claim 11 wherein said elastic waist barrier has a length of about 15 millimeters or more.
13. A disposable absorbent training pant, comprising:
a three-dimensional pant body defining a pant interior, a waist opening, and a pair of leg openings, an absorbent structure positioned in said pant interior, a waist peripheral region having a waist peripheral edge generally circumscribing said waist opening, and an elastic waist barrier in said pant interior and being joined to said waist peripheral region to form a trough therewith, said elastic waist barrier comprising a first gatherable layer and a means for elasticizing said first gatherable layer, said elastic waist barrier having a hydrohead value of at least about 30 centimeters.
a three-dimensional pant body defining a pant interior, a waist opening, and a pair of leg openings, an absorbent structure positioned in said pant interior, a waist peripheral region having a waist peripheral edge generally circumscribing said waist opening, and an elastic waist barrier in said pant interior and being joined to said waist peripheral region to form a trough therewith, said elastic waist barrier comprising a first gatherable layer and a means for elasticizing said first gatherable layer, said elastic waist barrier having a hydrohead value of at least about 30 centimeters.
14. The pant of claim 13 wherein said first gatherable layer is liquid impermeable.
15. The pant of claim 13 wherein said means for elasticizing is liquid impermeable.
16. The pant of claim 13 wherein said means for elasticizing is a layer of elastic material.
17. The pant of claim 13 wherein said means for elasticizing is a plurality of elastic strands.
18. The pant of claim 13 wherein said absorbent structure comprises an absorbent front edge, and wherein said elastic waist barrier is joined to said waist peripheral region by a liquid barrier bond line, said absorbent front edge being spaced from said liquid barrier bond line a distance of about 2 centimeters or less.
19. The pant of claim 13 wherein said elastic waist barrier has a length of about 15 millimeters or more.
20. The pant of claim 13 wherein said waist elastic barrier further comprises a second gatherable layer, said means for elasticizing also elasticizing said second gatherable layer.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US55636895A | 1995-11-13 | 1995-11-13 | |
| US08/556,368 | 1995-11-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2190287A1 true CA2190287A1 (en) | 1997-05-14 |
Family
ID=24221061
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2190287 Abandoned CA2190287A1 (en) | 1995-11-13 | 1996-11-13 | Disposable absorbent training pant having improved recumbent waste containment features |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2190287A1 (en) |
-
1996
- 1996-11-13 CA CA 2190287 patent/CA2190287A1/en not_active Abandoned
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0869756B1 (en) | Absorbent article using extensible leg cuffs | |
| AU736116B2 (en) | Absorbent article with enhanced elastic design for improved aesthetics and containment | |
| US6371950B1 (en) | Incontinence article for males | |
| US5853403A (en) | Absorbent article with body contacting liquid control member | |
| US6648869B1 (en) | Vertically pleated diaper liner | |
| AU743281B2 (en) | Disposable absorbent article with integrally formed elastized containment flaps and cuffs | |
| EP0059014B1 (en) | Disposable absorbent article having an improved liquid containment construction | |
| US8043275B2 (en) | Absorbent garment with dual containment flaps | |
| KR19990067477A (en) | Absorbents with improved waist elasticity and leakage | |
| IL124339A (en) | Absorbent article with improved elastic margins and containment system | |
| IE57317B1 (en) | Disposable diapers with unitary waistshield and elastically expansible waistbands | |
| JP3585499B2 (en) | Absorbent products with liquid control members that come into contact with the body | |
| US20220192898A1 (en) | Absorbent article and method for manufacturing absorbent article | |
| JP3986446B2 (en) | Absorbent articles | |
| JP3986447B2 (en) | Absorbent articles | |
| CA2190287A1 (en) | Disposable absorbent training pant having improved recumbent waste containment features | |
| KR100469184B1 (en) | Absorbent Article with Body Contacting Liquid Control Member | |
| MXPA98009433A (en) | Absorbent article having a recolecc duct | |
| MXPA00004499A (en) | Absorbent article having a multilayered containment barriers |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |
Effective date: 20001114 |