CA1176401A - Disposable diaper with improved body conformity and liquid retention - Google Patents
Disposable diaper with improved body conformity and liquid retentionInfo
- Publication number
- CA1176401A CA1176401A CA000422735A CA422735A CA1176401A CA 1176401 A CA1176401 A CA 1176401A CA 000422735 A CA000422735 A CA 000422735A CA 422735 A CA422735 A CA 422735A CA 1176401 A CA1176401 A CA 1176401A
- Authority
- CA
- Canada
- Prior art keywords
- absorbent panel
- facing
- elastic elements
- layer
- disposable diaper
- 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.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F13/00—Bandages or dressings; Absorbent pads
- A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
- A61F13/45—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the shape
- A61F13/49—Absorbent articles specially adapted to be worn around the waist, e.g. diapers
- A61F13/49007—Form-fitting, self-adjusting disposable diapers
- A61F13/49009—Form-fitting, self-adjusting disposable diapers with elastic means
Landscapes
- Health & Medical Sciences (AREA)
- Epidemiology (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Vascular Medicine (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Absorbent Articles And Supports Therefor (AREA)
- Orthopedics, Nursing, And Contraception (AREA)
Abstract
ABSTRACT
DISPOSABLE DIAPER WITH IMPROVED BODY
CONFORMITY AND LIQUID RETENTION
A disposable diaper having improved fit and liquid containment provided by gathering means adjacent at least one edge of the absorbent panel, said gathering means including at least two separately extending, effectively elastic elements. Each of the effectively elastic elements applies a gathering force to a zone of the diaper, thereby defining multiple lines of gasketing about the leg or waist openings.
DISPOSABLE DIAPER WITH IMPROVED BODY
CONFORMITY AND LIQUID RETENTION
A disposable diaper having improved fit and liquid containment provided by gathering means adjacent at least one edge of the absorbent panel, said gathering means including at least two separately extending, effectively elastic elements. Each of the effectively elastic elements applies a gathering force to a zone of the diaper, thereby defining multiple lines of gasketing about the leg or waist openings.
Description
-1- JBP 1~7 DISPOSABLE DIAPER WITH IMPROVED BODY
CONFORMITY AND LIQUID RETENTION
~5=~gL ~
The present invention relates to improve-ments in disposable diapers which enable the dlaper to closely conform to the torso of a baby. The diaperls of the present invention accomplish this without causing any discomfort to the baby~ while at the same time providing improved gasketing around the thlghs resulting in improved liquid containment.
In the recent past dlsposable diapers have been introducecl into the marketplace which have a ~lrrow but relatively thick strip of elastic at each side thereof~ so as to gather the side margins of the diaper in a manner similar to that of conventio~al moisture-impermeable panties. Such diapers are made generally in accordance with tAe teachings of U.S. Patent No.
3,860,003. In order for the elastic members to be effective in such diapers, it is necessary that the elastic members be spaced relatively far from the side marginal edges of the absorbent panel of the diaper, and for the elastic members to be associated with thin, highly flexible facing and backing layers. As a result, when such diapers are placed upon a baby, the narrow but relatively thick elastic members cause a narrow band of the facing layer to bear against the beby's skin with substantially line contact. This results in a high degree of stress concentration that may cause pinchinr and irritation of the babyls skin.
CONFORMITY AND LIQUID RETENTION
~5=~gL ~
The present invention relates to improve-ments in disposable diapers which enable the dlaper to closely conform to the torso of a baby. The diaperls of the present invention accomplish this without causing any discomfort to the baby~ while at the same time providing improved gasketing around the thlghs resulting in improved liquid containment.
In the recent past dlsposable diapers have been introducecl into the marketplace which have a ~lrrow but relatively thick strip of elastic at each side thereof~ so as to gather the side margins of the diaper in a manner similar to that of conventio~al moisture-impermeable panties. Such diapers are made generally in accordance with tAe teachings of U.S. Patent No.
3,860,003. In order for the elastic members to be effective in such diapers, it is necessary that the elastic members be spaced relatively far from the side marginal edges of the absorbent panel of the diaper, and for the elastic members to be associated with thin, highly flexible facing and backing layers. As a result, when such diapers are placed upon a baby, the narrow but relatively thick elastic members cause a narrow band of the facing layer to bear against the beby's skin with substantially line contact. This results in a high degree of stress concentration that may cause pinchinr and irritation of the babyls skin.
2- JBP 127 The problems attributable to the unduly hiCh compressive force caused by such narrow b~lt; relatively thick elastic strips of the prior art cliapers mentioned above are particularly acute when the baby has voided and the diaper is we~. Because the backing and facing layers are so highly flexible, when the diaper is wet and conditions are present tending to cause hydration of the baby's skin, the narrow elastic members sometimes cause the facing layer to press against the skirl with sufficient force to injure the skin. Also, the elastic members in prior art diapers of the type described above cause the diaper to gradually creep upwardly upon the baby's thighs~ As a result~ the forces applLed to the skin by the stressed elastic members increase the longer the diaper is worn, Summary_of the ~nvention In additlon to those elements whlch are present in currently commercially available products, i.e.~ a moisture pervious facing adapted to engage the baby's skin~ an absorbent batt or panel ad~acent to the facing3 and an outer moisture~impervious backing over the absorbent batt, the diapers of the present invention include gathering means about the leg and/or waist openings of the diaper which include at least two separate and distinct effectively elastic elements. Each of said elastic elements applies a gathering force to a zone of the diaper, thereby aefining more than one line of gasketing.
The elastic members may be positioned in spaced parallel relationship with respect to one another 3G and may substantially be parallel the straight or con-toured edge of the ~ aper absorbent panel or facing layer. The elastic members may also be positioned in non-parallel relationship; for instance, when the edge of the absorbent panel is non-parallel with the edge of the diaper, at least one of the elastic members may be ~7~;401~
~3~ JBP 127 positioned parallel to the edge of the absorbent panel~
and at least one elastic member may be posltioned parallel to the edge of the diaper. It is also con-templated that the separately positioned elastic members which c~mprise the gathering means may be sub~ected to different degrees of stretch or elongatlon when secured to the diaper, providing even greater body conformity and wearer comfort.
Diapers constructed in accordance with the present invention have several unexpected advantages, particularly as compared to the prior art diapers of the type disclosed in U.S~ Patent No. 3,860,003. In this regard, by utilizing spaced multlple elastlc members as the gathering means~ the area of the f`acing that is pressed against the baby's skin i~ relatlvely large, distributing the force applied to the skin over a relatlvely large area and thereby minimizin~ the possibility of irritation. Because of the relatively large area of facing engaging the baby's skin and the multiple gathering zones or lines of gasketing~ improved liquid containment around the thighs and waist may be effected. In this regard, it is significant that absorptive materials effect at least in part th- liquid containment, in contradistinction to the relatively non-absorbent facing in U.S. Patent No. 3,SoO,003 which provides little, if any gasketing action. As will appear in more detail from the following description, diapers of the present invention provide improved fit 3 and an improved liquid seal around the baby's legs and/or waist without irritation to the baby's skin.
Brief Description of the Drawings In the drawings, Figure 1 is a perspective view illustrating one embodiment of a disposable diaper of the present invention with a portion broken aw.ay to show interior detail;
~i7~401 ~4~ JBP 127 Figure 2 is an exploded perspective view showing relative positioning of diaper elements during manufacture of the diaper depicted in Figure l;
Figure 3 is a perspective view of the S diaper of Figure 1 illustrating diaper con~iguration when applied about a ba~y;
Figure 4 is a perspective view showing another embodiment of the disposable diaper of this invention;
Figure 5 is a plan view of yet another embodiment of a disposable diaper of this invention with a portion broken away to show interior detail;
Figure 6 is an enlarged partial cross-section of Figure 5 taken along lines 6-6;
Figure 7 is a plan view of a still further embodiment of a disposable diaper of this invention with a portion broken away to show interior detail;
Figure 8 is a plan view of an additional embodiment o~ a disposable dlaper of this invention 23 with a portion broken away to show interior detail;
Figure 9 is an enlarged cross-sectional view of the diaper of Figure 8 taken along lines 9-9;
Figure 10 is a plan view of another embodi-ment of the disposable diaper of the present invention;
~7 Figure 11 is an exploded perspective view of the elements of the diaper illustrated in Figure 10;
Figure 12 is a plan view of yet another embodiment of the disposable diaper of the present inver.tion; and 33 Figure 13 is a plan view of still another e,..bodiment of the disposable diaper of the present invention.
Descripti3n of the Preferred ~Ibodiments For a disposable diaper of the present in-~en~iorl the gathering means is a plurality of readily __ stretch~ble, elastic, preferably thermoplastic members ~L176~0~
each of which possesses a certain minimum elastic recovery, and which co-operate to pro~uce the same effect as a single width elastic member.
The term "elasticl', as used herein, refers to sheets, films, ribbons and the like which have a recovery of at least 90 percent, when elongated at least 10 percent of their yield point and measured in accordance with the following formula:
Percent retraction - Le Lt ~ 100 where ~O ~ original length of sample Le ~ fully extended length Lt ~ length of sample measured three seconds after released from extenled length.
The thickness of the elastic ~emberc is generally 10 mils or less, and preferably about 0.5 to ab~ut 5 mils. The elastic members have an extensibility to rupture of at least about 300 percent, pre~erably about 400 to about 1000 percent and a recovery at 50 percent elongation of at least about 75 percent, and preferably at least about 80 percent. For ease of stretchability, the modulus of elasticity Gf the el~stic member at 50 percent elon~atiorl should ~. t exceed about 2000 pounds per square inch, and preferably is abou~ 100 to about 200 pounds per square inch.
Referring to Figure 1, disposable di~per 10 illustrating one embodiment ~f the present invention is pro-~ided witn marOinal longitudinal gatherinO .~ans in opposite side margins 11 and 12 adapted to provide enhanced fit and gasketing about the baby's thigns.
Additionally, optional transverse gathering m-ans are provided in end margins lj and 14 for enh_nc-d fi~ about the baby's waist. The gathering means in eacn side m~rgin include at least tWJ separate and distinct l~ngitudinally extending effectively elastic elemen s such as elastic elements 15 in side margin 11. Tile optional transverse gatnering means in the -nd margins ~76~
of diaper 10 can be similar elastic elements such as elements 16 in end margin 14. Diaper 10 addition~lly includes first outer layer or bac~ing 17 made of a moisture-imparvious web, ~ generally rectangular absorbent panel 18 positioned in superposed relation-ship with respect to the backing, and second outer layer or facing lg made of a moisture-pervious or permeable web and positioned in superposed relationship with respect to absorbent panel 18. For securement about a baby, diaper 10 is provided with pressure-sensitive adhesive tape tabs 20 and 21. The gathering means are generally parallel to the longitudinal si~e mar~ins of panel 18~ and when the gatherlng means are in a relaxed state, diaper 10 assumes a boat-like confi~ura~
tion as shown in Figure 1~ with side mar~ins 11 and 12 having a reduced length.
The individual components of disp~sable diaper 10 are illustrated in Figure 2. Absorbent panel 18 is superposed over backing 17 and is secured thereto 2~ by a series of glue lines 23 deposited on backing 17.
Absorbent panel 18 is of smaller area than backing 17, and, when substantiall~ centered on backing 17, is spaced from longitudinal sides 24 and 25 as well as transverse sides or ends 26 and 27 and thereby defines the side and end marginal portions of diaper 10.
Absorbent panel 18 is flanked on all four sides thereof by elastic elements 15, 16, 21 and 22 which, in an ex-tended state, are secured to backing 17 by means ^f an elastic or inelastic adhesive, heat sealing, sonic sealing described below, or in any other convenient manner. Moisture-pervious facing 19 is superposed over absorbent panel 18, is larger in area than panel 13, and is secured to backing 17, usually by means of the exposed end portions of glue lines 23. However, other secure-~ent means can be utilized, if desired. Facing 19 mayalso be secured to elastic elements 15, 16, 21 and 22 ~L~7~
~7~ JBP 127 in a manner similar to the securement thereof to backlng 17.
As ~tated a~ove~ the elastic elements may be conveniently secured ln place ultrason~cally, such as by the use of apparatus of the type that is commercially available ~rom Branson Instruments, Inc. o:E Stanford~
Connecticut. Such apparatus conventio.nally includes an anvil and a horn that are positioned i:n juxtaposed re-lationship to one another, and the parts to be ~oined are inserted therebetween~ The hor~ is energized to transmit vibrations in the ultrasonic frequency range ~nto the parts to be joined. In the present instance, the elastic elements are elongated between backing layer 17 and faclng layer 19, and the layers placed between a horn which co~cts with an anvil which moves in registration with the prod~ t to provide spaced rows of simulated stitching. In this regard, the anvil of the ultrasonic sealing appar&tus preferably i~ provided with ~ plurali~y of spaced land a.reas so that the stretched elastlc elements are secured in place by a plurality of spaced securement 7.ones.
Spaced securement zones are also provided when the method of securement is heat sealing or inelastic adhesive. When elastic adhesive is used, lines of attachment may be continuous.
The configuration that disposable diaper 10 assumes when applied to a baby is illustrated in Figure 3.
partially-extended diaper side margins 11 and 12 provide a comfortable yet positive seal about the baby's th~ghs that readily accommodates leg movements of the baby, while optional elastic elements in diaper end margins 13 and 14 assure good fit about the baby's waist.
Figure 4 shows disposable diaper 30 that is similar to disposable diaper 10 but lacks the optional gathering means in diaper end margin 33. In the embodiment eY.emplified by Figure 4 the gathering means in diaper end margin 34 is similar to gathering means 16 in Figure 1 31 ~7~
and performs in the same manner. The construction of diaper side margins 31 and 32 is substantially the same as in diaper side margins 11 and 12.
In the embodiment illustrated by Figure 5 disposable diaper 60 is provided with absorbent p3nel 68 having curvilinear side cut-outs 71 and 72 and sandwiched between facing 69 and backing 67. Glue lines 65 serve to secure panel 68 and facing 69 to backing 67. ~1astic elements 63 and 64 are situated in generally rectilinear diaper side margins 62 and 61. Elastic elements 63 and 64 extend substantially the entire length of diaper side margins 62 and 61, respectively, and are secured to backing 67 by spaced outer glue lines 77 and 78. Glue lines 77 are illustrated in cross-section ln Figure 6.
The separate and distinct elastic elements of the gathering means provlde separate lines of ~athering or simulated gathered stltching which in turr, create separate llnes of gasketing of the puckered facing a~ainst the leg of the wearer. Protrud~ng ears 73, 74, 75 and ~6 of absorbent panel 68 overlap elastic elements 63 and 64 and provide additional absorbent capacity which can be readily utilized by building into absorbent panel 68 appropriake capillary transport means. Adhesive tape tab means 66 and 70 provide means for securing diaper 60 about a baby.
In the embodiment of Figure 7, disposable diaper 80 is provided with substantlally rectangular absorbent panel 88 having generally rectilinear sides, sandwiched between backing 87 and facing 89, and together with backing 87 and facing 89 defining diaper side margins 81 and 82. Curvilinear cut-outs 97 and 98 are provided n the respective central portions of margins 81 and 82 for further fit enhancement. Prestretched elastic elements 83a & 83b and 84a & 84b are positioned in respective margins 82 and 81 and are secured to backing 87 and facing 89 along the longitudinal sides of absorbent panel 88.
In this particular embodiment, the inner elastic elements 83b and 84a are prestretched to a greater or larger degree ~76~
~9~ JBP 127 of elongation than the outer elastic elements 83a and 84b; thus, though the inner and outer elastic elements may be of the same material and of the sa~e width, the inner elastic elements will exhibit a different and greater degree of elasticlty. Though in other instances it may be desirable to subject the out;er elastic elements to a greater degree of elongation to achieve a greater degree of elasticity, in this embodiment, wherein the inner elastic elements lie close to or even underly the edge of the absorbent panel, a better fit is achieved when the inner elastic elements have a greater degree of elasticity so as to be able to contract the side edges of the absorbent panel~ In this partlcular e~nbodiment, the elast~c elements have been prestre~ched to 80 E)ercent elongation while the outer elastlc elements have b~en pres~retched to only 70 percent elongation~ ho~ever the degr~e of elongation and the difference in de~ree of elongation be~ween the inner and outer elas~ic elements will vary with the specification of the materials used in their configuration within the final diaper pro~uct.
Glue lines 85 secure facinæ 89 and absorbent panel 88 to backing 87, and adhesive tape tabs 85 and 90 provide diaper securement means.
Yet another embodiment of a disposable diaper according to the present invention is sho~n in Figures 8 and 9 where disposable diaper 100 is provided with shaped absorbent panel 108 having curvilinear cut-outs 111 and 112 and cen~rally ~uxtaposed between backing 107 and facing 109. Both panel 108 and facing 109 are secureà to backing 107 by a plurality of longitudinally extendins glue lines 105. Curvilinear cut-outs 117 and 118, similar in con-figuration but of smaller size than cut-outs 111 and 112, are provided in the side portions of facins 109 and backing 107 that form diaper side marginal portions 101 and 102, respectively, so that margin cut-out 117 subtends panel cut-out 111 and margin cut-out 118 subtends panel cut-out 112. Elastic elements 103 are positioned in diaper side ~176~0~L
~narginal portions 102 between protruding ears 113 and 11 of absorbent panel 108 and are secured to faclng 109 and backing 107 by spaced lines of attachrnent 119. In a slmi-lar manner, elastic elements 104 are positloned in diaper side m~rginal portion 101 between protruding ears 115 and 116 ofabsorbent panel 108 and are secured to facing 109 and backing 107. Facing 109 and bac~Lng 107 are not secured to aach other in the side marginal portion between the gathering means and the longitudinal side edge of the diaper, creating a soft, ruffly side edge of the diaper.
~iaper securement means are provided by adhesive tape tabs 106 and 110.
The separate and distinct multiple el~stic elements create plural lines of se~ling or gasket~rlg about the leg of the wearer, aided by the puckerin~s or gathering o~ the f`acing layer ad~acent each el~stlc:
element, thereby providing improved llquid containment at the leg opening.
Referring now to Flgures 10 and 11, a stlll further embodiment of the invention i~ il'ustrated in its entirety at 120, and includes a first outer layer 121 in the form of a moisture-pervious facing, a second outer layer 122 in the form of a moisture-impervious backing, a third layer 123 in the form of an absorbent panel sand-wiched therebetween, and adhesive tape tabs 140. Outer layers 121 and 122 have the same outer dimensions and are coterminous with one another. Panel 123 has an extern31 com iguration similar to layers 121 and 122, and is smaller th3n and centered relative to layers 121 and 122. Parallel gl:- ~-nes 124 on b3cking 122 secure the p3nel to the b~cking, and the outermost glue lines (and the ends of the intermedi~te glue lines) secure the portions of layers 121 and 122 that extend beyond panel 123 to one another.
The end portions 125 and 126 of p~nel 123 are generally equal in width and are wider than the p3nel mid-portion 127. For improved fit, the narrowest part 128 of the panel mid-portion is offset toward panel end portion ~1'76~
~ JBP 127 126, the portion that is adapted to be placed in ~ront of the infant. Panel portion 12~ I!S of relatively short length and ls formed between parallel side edges 12~
and 128b. Panel slde edges 129~ 130~ ~ 132 flare outwardly from the ends of edges 1~7a and 1~8a and terminate ln end portion 129a parallel with end portion 131a and end porti~n 130a parallel with end portion 132a.
In a most preferred embodiment of the invention, edges 1?9 and 131 are disp~sed at an angle of 25 and edges 130 and 132 are disposed at an angle of 35~, so that the included angle between edges 129 and 130 and edges 131 an~ 132 is 120'.
As with the previously described e~bodi~ents, di~per 120 includes ~atharing means 134 and 135 at opposite sides of the diaper, and optional gathering msans 136 and 137 at opposite ends of the diaper. The illustrat~sd gathering means are in the form o~` elon~ated elastic ele-ments that are secured in a stretched condition to la~erA
121 and/or 122.
Illustrated in Figure 12 is a disposable diaper 140, with facing layer 141, and contoure~ absorbent p~nel 142 attached by glue lines 144 to backing layer 1~3.
The gathering means in the side margin of the diaper in-cludes two spaced elastic elements 145 and 1460 The elastic elements are non-parallel. Elastic element 146 substantially parallels the contoured edge of the absor-bent panel, while elastic element 145 is substantially perpendicular to end edge 147 of the diaperO The diaper is provided with adhesive tape tab fasteners 148.
The elastic members may be positioned in spaced parallel relationship with respect to one another 3G and may substantially be parallel the straight or con-toured edge of the ~ aper absorbent panel or facing layer. The elastic members may also be positioned in non-parallel relationship; for instance, when the edge of the absorbent panel is non-parallel with the edge of the diaper, at least one of the elastic members may be ~7~;401~
~3~ JBP 127 positioned parallel to the edge of the absorbent panel~
and at least one elastic member may be posltioned parallel to the edge of the diaper. It is also con-templated that the separately positioned elastic members which c~mprise the gathering means may be sub~ected to different degrees of stretch or elongatlon when secured to the diaper, providing even greater body conformity and wearer comfort.
Diapers constructed in accordance with the present invention have several unexpected advantages, particularly as compared to the prior art diapers of the type disclosed in U.S~ Patent No. 3,860,003. In this regard, by utilizing spaced multlple elastlc members as the gathering means~ the area of the f`acing that is pressed against the baby's skin i~ relatlvely large, distributing the force applied to the skin over a relatlvely large area and thereby minimizin~ the possibility of irritation. Because of the relatively large area of facing engaging the baby's skin and the multiple gathering zones or lines of gasketing~ improved liquid containment around the thighs and waist may be effected. In this regard, it is significant that absorptive materials effect at least in part th- liquid containment, in contradistinction to the relatively non-absorbent facing in U.S. Patent No. 3,SoO,003 which provides little, if any gasketing action. As will appear in more detail from the following description, diapers of the present invention provide improved fit 3 and an improved liquid seal around the baby's legs and/or waist without irritation to the baby's skin.
Brief Description of the Drawings In the drawings, Figure 1 is a perspective view illustrating one embodiment of a disposable diaper of the present invention with a portion broken aw.ay to show interior detail;
~i7~401 ~4~ JBP 127 Figure 2 is an exploded perspective view showing relative positioning of diaper elements during manufacture of the diaper depicted in Figure l;
Figure 3 is a perspective view of the S diaper of Figure 1 illustrating diaper con~iguration when applied about a ba~y;
Figure 4 is a perspective view showing another embodiment of the disposable diaper of this invention;
Figure 5 is a plan view of yet another embodiment of a disposable diaper of this invention with a portion broken away to show interior detail;
Figure 6 is an enlarged partial cross-section of Figure 5 taken along lines 6-6;
Figure 7 is a plan view of a still further embodiment of a disposable diaper of this invention with a portion broken away to show interior detail;
Figure 8 is a plan view of an additional embodiment o~ a disposable dlaper of this invention 23 with a portion broken away to show interior detail;
Figure 9 is an enlarged cross-sectional view of the diaper of Figure 8 taken along lines 9-9;
Figure 10 is a plan view of another embodi-ment of the disposable diaper of the present invention;
~7 Figure 11 is an exploded perspective view of the elements of the diaper illustrated in Figure 10;
Figure 12 is a plan view of yet another embodiment of the disposable diaper of the present inver.tion; and 33 Figure 13 is a plan view of still another e,..bodiment of the disposable diaper of the present invention.
Descripti3n of the Preferred ~Ibodiments For a disposable diaper of the present in-~en~iorl the gathering means is a plurality of readily __ stretch~ble, elastic, preferably thermoplastic members ~L176~0~
each of which possesses a certain minimum elastic recovery, and which co-operate to pro~uce the same effect as a single width elastic member.
The term "elasticl', as used herein, refers to sheets, films, ribbons and the like which have a recovery of at least 90 percent, when elongated at least 10 percent of their yield point and measured in accordance with the following formula:
Percent retraction - Le Lt ~ 100 where ~O ~ original length of sample Le ~ fully extended length Lt ~ length of sample measured three seconds after released from extenled length.
The thickness of the elastic ~emberc is generally 10 mils or less, and preferably about 0.5 to ab~ut 5 mils. The elastic members have an extensibility to rupture of at least about 300 percent, pre~erably about 400 to about 1000 percent and a recovery at 50 percent elongation of at least about 75 percent, and preferably at least about 80 percent. For ease of stretchability, the modulus of elasticity Gf the el~stic member at 50 percent elon~atiorl should ~. t exceed about 2000 pounds per square inch, and preferably is abou~ 100 to about 200 pounds per square inch.
Referring to Figure 1, disposable di~per 10 illustrating one embodiment ~f the present invention is pro-~ided witn marOinal longitudinal gatherinO .~ans in opposite side margins 11 and 12 adapted to provide enhanced fit and gasketing about the baby's thigns.
Additionally, optional transverse gathering m-ans are provided in end margins lj and 14 for enh_nc-d fi~ about the baby's waist. The gathering means in eacn side m~rgin include at least tWJ separate and distinct l~ngitudinally extending effectively elastic elemen s such as elastic elements 15 in side margin 11. Tile optional transverse gatnering means in the -nd margins ~76~
of diaper 10 can be similar elastic elements such as elements 16 in end margin 14. Diaper 10 addition~lly includes first outer layer or bac~ing 17 made of a moisture-imparvious web, ~ generally rectangular absorbent panel 18 positioned in superposed relation-ship with respect to the backing, and second outer layer or facing lg made of a moisture-pervious or permeable web and positioned in superposed relationship with respect to absorbent panel 18. For securement about a baby, diaper 10 is provided with pressure-sensitive adhesive tape tabs 20 and 21. The gathering means are generally parallel to the longitudinal si~e mar~ins of panel 18~ and when the gatherlng means are in a relaxed state, diaper 10 assumes a boat-like confi~ura~
tion as shown in Figure 1~ with side mar~ins 11 and 12 having a reduced length.
The individual components of disp~sable diaper 10 are illustrated in Figure 2. Absorbent panel 18 is superposed over backing 17 and is secured thereto 2~ by a series of glue lines 23 deposited on backing 17.
Absorbent panel 18 is of smaller area than backing 17, and, when substantiall~ centered on backing 17, is spaced from longitudinal sides 24 and 25 as well as transverse sides or ends 26 and 27 and thereby defines the side and end marginal portions of diaper 10.
Absorbent panel 18 is flanked on all four sides thereof by elastic elements 15, 16, 21 and 22 which, in an ex-tended state, are secured to backing 17 by means ^f an elastic or inelastic adhesive, heat sealing, sonic sealing described below, or in any other convenient manner. Moisture-pervious facing 19 is superposed over absorbent panel 18, is larger in area than panel 13, and is secured to backing 17, usually by means of the exposed end portions of glue lines 23. However, other secure-~ent means can be utilized, if desired. Facing 19 mayalso be secured to elastic elements 15, 16, 21 and 22 ~L~7~
~7~ JBP 127 in a manner similar to the securement thereof to backlng 17.
As ~tated a~ove~ the elastic elements may be conveniently secured ln place ultrason~cally, such as by the use of apparatus of the type that is commercially available ~rom Branson Instruments, Inc. o:E Stanford~
Connecticut. Such apparatus conventio.nally includes an anvil and a horn that are positioned i:n juxtaposed re-lationship to one another, and the parts to be ~oined are inserted therebetween~ The hor~ is energized to transmit vibrations in the ultrasonic frequency range ~nto the parts to be joined. In the present instance, the elastic elements are elongated between backing layer 17 and faclng layer 19, and the layers placed between a horn which co~cts with an anvil which moves in registration with the prod~ t to provide spaced rows of simulated stitching. In this regard, the anvil of the ultrasonic sealing appar&tus preferably i~ provided with ~ plurali~y of spaced land a.reas so that the stretched elastlc elements are secured in place by a plurality of spaced securement 7.ones.
Spaced securement zones are also provided when the method of securement is heat sealing or inelastic adhesive. When elastic adhesive is used, lines of attachment may be continuous.
The configuration that disposable diaper 10 assumes when applied to a baby is illustrated in Figure 3.
partially-extended diaper side margins 11 and 12 provide a comfortable yet positive seal about the baby's th~ghs that readily accommodates leg movements of the baby, while optional elastic elements in diaper end margins 13 and 14 assure good fit about the baby's waist.
Figure 4 shows disposable diaper 30 that is similar to disposable diaper 10 but lacks the optional gathering means in diaper end margin 33. In the embodiment eY.emplified by Figure 4 the gathering means in diaper end margin 34 is similar to gathering means 16 in Figure 1 31 ~7~
and performs in the same manner. The construction of diaper side margins 31 and 32 is substantially the same as in diaper side margins 11 and 12.
In the embodiment illustrated by Figure 5 disposable diaper 60 is provided with absorbent p3nel 68 having curvilinear side cut-outs 71 and 72 and sandwiched between facing 69 and backing 67. Glue lines 65 serve to secure panel 68 and facing 69 to backing 67. ~1astic elements 63 and 64 are situated in generally rectilinear diaper side margins 62 and 61. Elastic elements 63 and 64 extend substantially the entire length of diaper side margins 62 and 61, respectively, and are secured to backing 67 by spaced outer glue lines 77 and 78. Glue lines 77 are illustrated in cross-section ln Figure 6.
The separate and distinct elastic elements of the gathering means provlde separate lines of ~athering or simulated gathered stltching which in turr, create separate llnes of gasketing of the puckered facing a~ainst the leg of the wearer. Protrud~ng ears 73, 74, 75 and ~6 of absorbent panel 68 overlap elastic elements 63 and 64 and provide additional absorbent capacity which can be readily utilized by building into absorbent panel 68 appropriake capillary transport means. Adhesive tape tab means 66 and 70 provide means for securing diaper 60 about a baby.
In the embodiment of Figure 7, disposable diaper 80 is provided with substantlally rectangular absorbent panel 88 having generally rectilinear sides, sandwiched between backing 87 and facing 89, and together with backing 87 and facing 89 defining diaper side margins 81 and 82. Curvilinear cut-outs 97 and 98 are provided n the respective central portions of margins 81 and 82 for further fit enhancement. Prestretched elastic elements 83a & 83b and 84a & 84b are positioned in respective margins 82 and 81 and are secured to backing 87 and facing 89 along the longitudinal sides of absorbent panel 88.
In this particular embodiment, the inner elastic elements 83b and 84a are prestretched to a greater or larger degree ~76~
~9~ JBP 127 of elongation than the outer elastic elements 83a and 84b; thus, though the inner and outer elastic elements may be of the same material and of the sa~e width, the inner elastic elements will exhibit a different and greater degree of elasticlty. Though in other instances it may be desirable to subject the out;er elastic elements to a greater degree of elongation to achieve a greater degree of elasticity, in this embodiment, wherein the inner elastic elements lie close to or even underly the edge of the absorbent panel, a better fit is achieved when the inner elastic elements have a greater degree of elasticity so as to be able to contract the side edges of the absorbent panel~ In this partlcular e~nbodiment, the elast~c elements have been prestre~ched to 80 E)ercent elongation while the outer elastlc elements have b~en pres~retched to only 70 percent elongation~ ho~ever the degr~e of elongation and the difference in de~ree of elongation be~ween the inner and outer elas~ic elements will vary with the specification of the materials used in their configuration within the final diaper pro~uct.
Glue lines 85 secure facinæ 89 and absorbent panel 88 to backing 87, and adhesive tape tabs 85 and 90 provide diaper securement means.
Yet another embodiment of a disposable diaper according to the present invention is sho~n in Figures 8 and 9 where disposable diaper 100 is provided with shaped absorbent panel 108 having curvilinear cut-outs 111 and 112 and cen~rally ~uxtaposed between backing 107 and facing 109. Both panel 108 and facing 109 are secureà to backing 107 by a plurality of longitudinally extendins glue lines 105. Curvilinear cut-outs 117 and 118, similar in con-figuration but of smaller size than cut-outs 111 and 112, are provided in the side portions of facins 109 and backing 107 that form diaper side marginal portions 101 and 102, respectively, so that margin cut-out 117 subtends panel cut-out 111 and margin cut-out 118 subtends panel cut-out 112. Elastic elements 103 are positioned in diaper side ~176~0~L
~narginal portions 102 between protruding ears 113 and 11 of absorbent panel 108 and are secured to faclng 109 and backing 107 by spaced lines of attachrnent 119. In a slmi-lar manner, elastic elements 104 are positloned in diaper side m~rginal portion 101 between protruding ears 115 and 116 ofabsorbent panel 108 and are secured to facing 109 and backing 107. Facing 109 and bac~Lng 107 are not secured to aach other in the side marginal portion between the gathering means and the longitudinal side edge of the diaper, creating a soft, ruffly side edge of the diaper.
~iaper securement means are provided by adhesive tape tabs 106 and 110.
The separate and distinct multiple el~stic elements create plural lines of se~ling or gasket~rlg about the leg of the wearer, aided by the puckerin~s or gathering o~ the f`acing layer ad~acent each el~stlc:
element, thereby providing improved llquid containment at the leg opening.
Referring now to Flgures 10 and 11, a stlll further embodiment of the invention i~ il'ustrated in its entirety at 120, and includes a first outer layer 121 in the form of a moisture-pervious facing, a second outer layer 122 in the form of a moisture-impervious backing, a third layer 123 in the form of an absorbent panel sand-wiched therebetween, and adhesive tape tabs 140. Outer layers 121 and 122 have the same outer dimensions and are coterminous with one another. Panel 123 has an extern31 com iguration similar to layers 121 and 122, and is smaller th3n and centered relative to layers 121 and 122. Parallel gl:- ~-nes 124 on b3cking 122 secure the p3nel to the b~cking, and the outermost glue lines (and the ends of the intermedi~te glue lines) secure the portions of layers 121 and 122 that extend beyond panel 123 to one another.
The end portions 125 and 126 of p~nel 123 are generally equal in width and are wider than the p3nel mid-portion 127. For improved fit, the narrowest part 128 of the panel mid-portion is offset toward panel end portion ~1'76~
~ JBP 127 126, the portion that is adapted to be placed in ~ront of the infant. Panel portion 12~ I!S of relatively short length and ls formed between parallel side edges 12~
and 128b. Panel slde edges 129~ 130~ ~ 132 flare outwardly from the ends of edges 1~7a and 1~8a and terminate ln end portion 129a parallel with end portion 131a and end porti~n 130a parallel with end portion 132a.
In a most preferred embodiment of the invention, edges 1?9 and 131 are disp~sed at an angle of 25 and edges 130 and 132 are disposed at an angle of 35~, so that the included angle between edges 129 and 130 and edges 131 an~ 132 is 120'.
As with the previously described e~bodi~ents, di~per 120 includes ~atharing means 134 and 135 at opposite sides of the diaper, and optional gathering msans 136 and 137 at opposite ends of the diaper. The illustrat~sd gathering means are in the form o~` elon~ated elastic ele-ments that are secured in a stretched condition to la~erA
121 and/or 122.
Illustrated in Figure 12 is a disposable diaper 140, with facing layer 141, and contoure~ absorbent p~nel 142 attached by glue lines 144 to backing layer 1~3.
The gathering means in the side margin of the diaper in-cludes two spaced elastic elements 145 and 1460 The elastic elements are non-parallel. Elastic element 146 substantially parallels the contoured edge of the absor-bent panel, while elastic element 145 is substantially perpendicular to end edge 147 of the diaperO The diaper is provided with adhesive tape tab fasteners 148.
3~ Figure 13 illustrates a disposable diaper 150 wherein the elastic elements 153 and 154 of the gathering means in the side margin are parallel throughout only a portion of their length. Absorbent panel 152 is essen-tially hourglass in shape, and has a more sharply defined ~5 contour in the crotch portion as opposed to the gently cur~ing contour of absorbent panel 142 of Figure 12. The elastic elemènts 153 and 154 are substantially parallel ~ ~764~
at the end portions of the diaper. Through the crotch portion of the diaper, elastic elem~ent 154 parallels the edge of the hourglass shaped absorbent panel, whlle elastic element 153 continues in a su~st3ntlally st~aight lin~, substantially perpendicular to the end edge 155 of the diaper. The diaper is also provicled with Eacing layer lS1, backing layer 158, adhesive tape tabs 157, and optionally, gathering means 156 in at least one end margin.
Elastic film elements suitable as gathering means for the diapers contemplated herein can be extruded to the desired thickness utili7ing unvulcanized, thermo-plastic compostions which are made up of an elast~.eric component and an optional compatib'e modifier which is a thermoplastic polymer of a relatively low molecular weight but 901id at amblent ternperature.
Illustratlve of the elastomeric components suitable for present purpo9es are block copolymers which comprise termlnal thermopla~tic polymer blocks and at least one non-terminal or lntermediate elastomerlc polymer block. Block copolymers of thls general type may be pre-pared using a step-wise polymerizatlon initiator, e.g., an organolithium compound. Such block polymerization techniques are well known in the art.
The elastomeric component can be llnear or radial Al-B-A2 block copolymers or mixtures thereof with simple Al-B block copolymers where Al and A2 can be alike or different and represent a thermoplastic polymer block, such as poly(vinyl arene) block, and B represen~s an elastomeric polymer block such as a conjugated diene or a lower (i.e., Cl-C4) alkene, The modifier component is a lcw molecular weight thermoplastic polymer having an aver-age molecular weight of about 500 to about 7500 and is present in the composition in an amount of about 0 to about 200 parts by weight per 100 parts by weight of the elastomeric component.
A preferred thermoplastic film composition for the elastic film elements compris~s an elastomeric ~'764~)~
component which contains, as a ma~or constituent thereof, an unvulcanized linear block copolymer of the general configuration Al - B _A2 wherein Al, A2 and B have the same meaning as hereinabove. In these block copolymers the A-blocks are derived from styrene or styrene homologuesg and the B-blocks are derived from con~ugated dienes or lower alkenes. The thermoplastic polymer modifler is co~patible wlth the elastomeric component and associates principally with the thermoplastic te~minal blocks of the aforesaid unvulcanized block copolymer. The thermoplastic polymer modifier preferably has an average molecular weight of about 1000 to 30003 and is present in the film composition in an amount of about 80 to about 200 par~s by weight per 100 parts by weight of the elastomeric c~ponent.
The preferred Al-B-A2 block copolymers have A-blocks derived, i.e.~ polymertzed or copolymerlzed, from styrene or styrene ho~ologues; and B-blocks derived from conjugated diene~, such as isoprene or butadtene, or fr~m lower alkenes, su~h as ethylene and butylene. Small pro-2~ portions of other monomers also m~y enter into the block copolymers themselves. The individual A-blocks can have an average molecular weight of at least about 6000~ preferably in the range of about 8000-30,000, and the A-blocks con-stitute about 5-50 percent, preferably about 10-30 percent, by weight of the block copolymer. The average molecular weight of the B-blocks for linear Al-B-A2 block copolymers preferably is in the range of about 45,000-180,000 and that of the linear copolymer itself, preferably is in the range of about 75,000-200,000. The average molecular weight of the radial Al-B-A2 block copolymers preferably is in the range of about 125,000-400,000. The term "linear block copolymer" (or copolymers) includes branched Al-B-A2 copolymers as well as unbranched A -B-A2 copolymers.
The radial Al-B-A2 copolymers useful for manufacture of elastic elements for diapers of this in-vention are of the type described in United States Letters patent No. 3,281,383 to Zelinski et al and conform to the ~:1764~
following general formula: (A-B-)nX, wherein A is a thermoplastic block polymerized from styrene or styrene homologues, B is an elastcmeric block derived from con-jugated dienes or lower alkenes, as indicated above, X
is an organic or inorganic connectine molecule, with a functionality of about 2 to 4 as described in Patent No.
3,281~383, or possibly with a higher functior~lity as described i.3 the article entitled ~New Rubber is Backed by Stars" appearlng on Page 35 of the June 11, 1975 iss of Chemical Week. As used hereinabove, "n" has a value correspcn~ing to the functionality of X.
The preferred elastic film elements are highly ther.moplastic and, though elastomeric, are unlike rubber in that the film exhibits a relatively sharp melting point and is capable of being heat shaped. Also, the ~lastic elements can form permanent heat seals to substrates such as non-woven fabrics, or the llke~ at rel~tivoly low he~-t sealing peak temperatures, generally not above about 350F~
Tne elements are highl~ ;lastic and has a relatively low 2~ rubber modulus, i.e., they exhlbit in at least one direction an elastic recovery from 50 percent stretch to ~t least 75 percent, preferably at least abo~t 80 percent, and a 50 percer+ rubber modulus of not above about 2000 pounds per square inch, preferably not above 1000 pounds per square 2, in^h at 50 percent elongation, The film elements also are very flexlble, extensible and SOL~ and normally exhibits a Gurley stiffness of about one or less at a film thickness of one mil, and an elongation to break of at least about 300 percent, preferably at least about 400 percent, in 3G at least or.e direction at ambient temperatures.
Several different types of facing m~terials may be used for diaper facing. For example, th~ facing may be a non-woven web made up of a mixture of fibers con-sisting predomirantly of inexpensive short cel ~losic fibers ,5 slch as wood pulp fibers or cotton linters, in amounts of about 75 percent to about 98 percent, the balance being textile length fibers such as rayon as described in U.S.
~ 1 7 ~ 4C 1 Patent No. 33633,348 to Liloia et al.
Non-woven facing materials suitable for use in disposable diapers of this invention can have fabric weights in the range of about .5 to 5 oz./yd.2 and den-slties of less than 0.15 g./cc~, generally in the rangeof about 0.05 to about 0.1 g./cc. The clry stren~th of the facing sheet for a fabric h~ving a weight of about 1.5 o~./yd.2 is at least 0.15 lbs./in. of width in the m~chine direction and at least 0.1 lbs./in. of width in the cross dlrection. Such fabrics have unusually good elongation, loft, softness, and drape characteristics.
Facings m~y also be m~de of an aperture~ non-woven fabric which is formed, ~or example, in accordance with the teachlngs of co~monly assigned U.S. Patent ~los.
2,8S2,251; 3,081,514 and 3,081~515~ Brie~ly~ such fabrics are foraminous structures wherein groups or groupings of fibers have been rearranged fro~ a fibrous non-woven starting web ~nto posltions surroundin6 less dense ~abrlc portions by passage of a fluid through the st~rting 2~ m~terial. The fibers within the groupings are mechanically interlo^ke~, and m3y be arranged into various patterns, as is well known by those skilled in the art, A suitable binder may be utilized to help retain the fibers in their rearranged locations, as is also well known by those skilled in the art. The fabric can be m~de of n~turally o~curring fibers, synthetic fibers, or blends thereof.
Typical facing sheets made of a fibrous polyester type material can have a weight of about 0.75 oz./~d. .
In addition, facings can be forled OL a non-3~ apertured material, such as a non-woven isotropic web, or of an apertured polyol-fin or polyester fil~. h~ving the desired moisture permeability. In all of the afore-mentioned facings the material should be relatively hYdrOPhObiC SO 3S to retard wicking within the facing.
The moisture-absorbent batt or panel of a desired shape but smaller than the facing and ~he ba-king, can be formed in accordance with the teachings of U.S.
, . .
1~7640~
Patent No. 3,612,055 to ~esek et al, A suitable backing m~terial for t~e diapers embodying the present invention can be an opaque polyole-fin~ e.g.~ polyethylene~ web about 0.001 lnch thick.
Another suitable m~terial for this p~rpose is a poly-eth~lene terephthalate web h~ving a thickness of about 0.0005 inch.
In use~ the disposable diaper is applie~ to the baby by laying out the diaper on ~ suit~ble flat surface and placing the baby thereon so that the ~1~isl-underlyin~ end of the diaper is that having the fasienQr means. The other en~ of the diaper then e,-~enls do-:n-w3rdly between the infant's legs. Ne~t, the downwardly extending enl of the diaper is brought up between the baby's legs to ~ position co~erin~ the perineu~. ~nd CC~
tiguous with the front portion of the baby's w~ist. Tne diaper is thereafter secured to the baby by pl~ci~_ t~
corners of the w~ist portion of the abdomen-coverlng en;;
as ~ar aroun~ the baby's w~ist as they will go and by bringing the corners of the underlying en~ of the dl~per into an overlapping relationship with the afore~entioned corners so th~t the diaper snugly encircles the baby's waist and provides a custo~ fit. Tne adhesi~re tab fasteners are then prepared for use anl the diape~ is securel in the desired position by si~ply urging the pressure-sensitive adhesive surface of the t~pe tab ir ^-n-tact with the adjacent o~lter surface o~ the op~osite corner of the diaper. Tne appliel diaper ass~lmes a con-figuration such as sho~n in rig~re 3.
3 The foregoing description an~ the drawings are illustrative anl are not to be t3'~en ~S limitinOo Still other variations an~ modifications are possibl-without departing fro~ the spirit anl sco~e of ~e present invention.
at the end portions of the diaper. Through the crotch portion of the diaper, elastic elem~ent 154 parallels the edge of the hourglass shaped absorbent panel, whlle elastic element 153 continues in a su~st3ntlally st~aight lin~, substantially perpendicular to the end edge 155 of the diaper. The diaper is also provicled with Eacing layer lS1, backing layer 158, adhesive tape tabs 157, and optionally, gathering means 156 in at least one end margin.
Elastic film elements suitable as gathering means for the diapers contemplated herein can be extruded to the desired thickness utili7ing unvulcanized, thermo-plastic compostions which are made up of an elast~.eric component and an optional compatib'e modifier which is a thermoplastic polymer of a relatively low molecular weight but 901id at amblent ternperature.
Illustratlve of the elastomeric components suitable for present purpo9es are block copolymers which comprise termlnal thermopla~tic polymer blocks and at least one non-terminal or lntermediate elastomerlc polymer block. Block copolymers of thls general type may be pre-pared using a step-wise polymerizatlon initiator, e.g., an organolithium compound. Such block polymerization techniques are well known in the art.
The elastomeric component can be llnear or radial Al-B-A2 block copolymers or mixtures thereof with simple Al-B block copolymers where Al and A2 can be alike or different and represent a thermoplastic polymer block, such as poly(vinyl arene) block, and B represen~s an elastomeric polymer block such as a conjugated diene or a lower (i.e., Cl-C4) alkene, The modifier component is a lcw molecular weight thermoplastic polymer having an aver-age molecular weight of about 500 to about 7500 and is present in the composition in an amount of about 0 to about 200 parts by weight per 100 parts by weight of the elastomeric component.
A preferred thermoplastic film composition for the elastic film elements compris~s an elastomeric ~'764~)~
component which contains, as a ma~or constituent thereof, an unvulcanized linear block copolymer of the general configuration Al - B _A2 wherein Al, A2 and B have the same meaning as hereinabove. In these block copolymers the A-blocks are derived from styrene or styrene homologuesg and the B-blocks are derived from con~ugated dienes or lower alkenes. The thermoplastic polymer modifler is co~patible wlth the elastomeric component and associates principally with the thermoplastic te~minal blocks of the aforesaid unvulcanized block copolymer. The thermoplastic polymer modifier preferably has an average molecular weight of about 1000 to 30003 and is present in the film composition in an amount of about 80 to about 200 par~s by weight per 100 parts by weight of the elastomeric c~ponent.
The preferred Al-B-A2 block copolymers have A-blocks derived, i.e.~ polymertzed or copolymerlzed, from styrene or styrene ho~ologues; and B-blocks derived from conjugated diene~, such as isoprene or butadtene, or fr~m lower alkenes, su~h as ethylene and butylene. Small pro-2~ portions of other monomers also m~y enter into the block copolymers themselves. The individual A-blocks can have an average molecular weight of at least about 6000~ preferably in the range of about 8000-30,000, and the A-blocks con-stitute about 5-50 percent, preferably about 10-30 percent, by weight of the block copolymer. The average molecular weight of the B-blocks for linear Al-B-A2 block copolymers preferably is in the range of about 45,000-180,000 and that of the linear copolymer itself, preferably is in the range of about 75,000-200,000. The average molecular weight of the radial Al-B-A2 block copolymers preferably is in the range of about 125,000-400,000. The term "linear block copolymer" (or copolymers) includes branched Al-B-A2 copolymers as well as unbranched A -B-A2 copolymers.
The radial Al-B-A2 copolymers useful for manufacture of elastic elements for diapers of this in-vention are of the type described in United States Letters patent No. 3,281,383 to Zelinski et al and conform to the ~:1764~
following general formula: (A-B-)nX, wherein A is a thermoplastic block polymerized from styrene or styrene homologues, B is an elastcmeric block derived from con-jugated dienes or lower alkenes, as indicated above, X
is an organic or inorganic connectine molecule, with a functionality of about 2 to 4 as described in Patent No.
3,281~383, or possibly with a higher functior~lity as described i.3 the article entitled ~New Rubber is Backed by Stars" appearlng on Page 35 of the June 11, 1975 iss of Chemical Week. As used hereinabove, "n" has a value correspcn~ing to the functionality of X.
The preferred elastic film elements are highly ther.moplastic and, though elastomeric, are unlike rubber in that the film exhibits a relatively sharp melting point and is capable of being heat shaped. Also, the ~lastic elements can form permanent heat seals to substrates such as non-woven fabrics, or the llke~ at rel~tivoly low he~-t sealing peak temperatures, generally not above about 350F~
Tne elements are highl~ ;lastic and has a relatively low 2~ rubber modulus, i.e., they exhlbit in at least one direction an elastic recovery from 50 percent stretch to ~t least 75 percent, preferably at least abo~t 80 percent, and a 50 percer+ rubber modulus of not above about 2000 pounds per square inch, preferably not above 1000 pounds per square 2, in^h at 50 percent elongation, The film elements also are very flexlble, extensible and SOL~ and normally exhibits a Gurley stiffness of about one or less at a film thickness of one mil, and an elongation to break of at least about 300 percent, preferably at least about 400 percent, in 3G at least or.e direction at ambient temperatures.
Several different types of facing m~terials may be used for diaper facing. For example, th~ facing may be a non-woven web made up of a mixture of fibers con-sisting predomirantly of inexpensive short cel ~losic fibers ,5 slch as wood pulp fibers or cotton linters, in amounts of about 75 percent to about 98 percent, the balance being textile length fibers such as rayon as described in U.S.
~ 1 7 ~ 4C 1 Patent No. 33633,348 to Liloia et al.
Non-woven facing materials suitable for use in disposable diapers of this invention can have fabric weights in the range of about .5 to 5 oz./yd.2 and den-slties of less than 0.15 g./cc~, generally in the rangeof about 0.05 to about 0.1 g./cc. The clry stren~th of the facing sheet for a fabric h~ving a weight of about 1.5 o~./yd.2 is at least 0.15 lbs./in. of width in the m~chine direction and at least 0.1 lbs./in. of width in the cross dlrection. Such fabrics have unusually good elongation, loft, softness, and drape characteristics.
Facings m~y also be m~de of an aperture~ non-woven fabric which is formed, ~or example, in accordance with the teachlngs of co~monly assigned U.S. Patent ~los.
2,8S2,251; 3,081,514 and 3,081~515~ Brie~ly~ such fabrics are foraminous structures wherein groups or groupings of fibers have been rearranged fro~ a fibrous non-woven starting web ~nto posltions surroundin6 less dense ~abrlc portions by passage of a fluid through the st~rting 2~ m~terial. The fibers within the groupings are mechanically interlo^ke~, and m3y be arranged into various patterns, as is well known by those skilled in the art, A suitable binder may be utilized to help retain the fibers in their rearranged locations, as is also well known by those skilled in the art. The fabric can be m~de of n~turally o~curring fibers, synthetic fibers, or blends thereof.
Typical facing sheets made of a fibrous polyester type material can have a weight of about 0.75 oz./~d. .
In addition, facings can be forled OL a non-3~ apertured material, such as a non-woven isotropic web, or of an apertured polyol-fin or polyester fil~. h~ving the desired moisture permeability. In all of the afore-mentioned facings the material should be relatively hYdrOPhObiC SO 3S to retard wicking within the facing.
The moisture-absorbent batt or panel of a desired shape but smaller than the facing and ~he ba-king, can be formed in accordance with the teachings of U.S.
, . .
1~7640~
Patent No. 3,612,055 to ~esek et al, A suitable backing m~terial for t~e diapers embodying the present invention can be an opaque polyole-fin~ e.g.~ polyethylene~ web about 0.001 lnch thick.
Another suitable m~terial for this p~rpose is a poly-eth~lene terephthalate web h~ving a thickness of about 0.0005 inch.
In use~ the disposable diaper is applie~ to the baby by laying out the diaper on ~ suit~ble flat surface and placing the baby thereon so that the ~1~isl-underlyin~ end of the diaper is that having the fasienQr means. The other en~ of the diaper then e,-~enls do-:n-w3rdly between the infant's legs. Ne~t, the downwardly extending enl of the diaper is brought up between the baby's legs to ~ position co~erin~ the perineu~. ~nd CC~
tiguous with the front portion of the baby's w~ist. Tne diaper is thereafter secured to the baby by pl~ci~_ t~
corners of the w~ist portion of the abdomen-coverlng en;;
as ~ar aroun~ the baby's w~ist as they will go and by bringing the corners of the underlying en~ of the dl~per into an overlapping relationship with the afore~entioned corners so th~t the diaper snugly encircles the baby's waist and provides a custo~ fit. Tne adhesi~re tab fasteners are then prepared for use anl the diape~ is securel in the desired position by si~ply urging the pressure-sensitive adhesive surface of the t~pe tab ir ^-n-tact with the adjacent o~lter surface o~ the op~osite corner of the diaper. Tne appliel diaper ass~lmes a con-figuration such as sho~n in rig~re 3.
3 The foregoing description an~ the drawings are illustrative anl are not to be t3'~en ~S limitinOo Still other variations an~ modifications are possibl-without departing fro~ the spirit anl sco~e of ~e present invention.
Claims (14)
1. A disposable diaper comprising: a moisture-permeable facing layer; an absorbent panel at one side of said facing layer, said absorbent panel being smaller than said facing layer so that side marginal portions of the facing layer extend outwardly beyond the side edges of said absorbent panel; a moisture-impervious backing layer at the side of said absorbent panel opposite said facing layer, said backing layer being larger than said absorbent panel so that side marginal portions of the backing layer extend outwardly beyond the side edges of said absorbent panel; means bonding said facing and backing layers to one another; and gathering means disposed in said side marginal portions, each of said gathering means including at least two spaced separate and distinct longitudinally extending, effectively elastic elements secured in each of said side marginal portions, whereby said gathering means provide improved conformity about the legs of the wearer without undue application of pressure upon the skin of the wearer and each of said elastic elements applies a gathering force to a zone of a side marginal portion thereby defining more than one gasketing line at the leg of the wearer for improved liquid containment.
2. A disposable diaper as in Claim 1 wherein the elastic elements are disposed between the facing layer and backing layer.
3. A disposable diaper as in Claim 2 wherein the elastic elements are secured to both the facing layer and backing layer.
4. A disposable diaper as in Claim 1 wherein the elastic elements in each side marginal portion are disposed in parallel relationship one to the other along their entire length.
5. A disposable diaper as in Claim 1 wherein at least one of the elastic elements in each side marginal portion is disposed parallel to a side edge of the diaper.
6. A disposable diaper comprising: a moisture-permeable facing layer; an absorbent panel at one side of said facing layer, said absorbent panel being smaller than said facing layer 90 that marginal portions of the facing layer extend outwardly beyond the edges of said absorbent panel; a moisture-impervious backing layer at the side of said absorbent panel opposite said facing layer, said backing layer being larger than said absorbent panel so that marginal portions of the facing extend outwardly beyond the edges of said absorbent panel, a moisture-impervious backing layer at the side of said absorbent panel opposite said facing layer, said backing layer being larger than said absorbent panel so that marginal portions of the backing layer extend outwardly beyond the edges of said absorbent panel;
means bonding said facing and backing layers to one another; and gathering means disposed in at least one marginal portion, said gathering means including at least two spaced longitudinally extending effectively elastic elements secured in said one marginal portion, whereby said gathering means provides improved body conformity without undue application of pressure upon the skin of the wearer.
means bonding said facing and backing layers to one another; and gathering means disposed in at least one marginal portion, said gathering means including at least two spaced longitudinally extending effectively elastic elements secured in said one marginal portion, whereby said gathering means provides improved body conformity without undue application of pressure upon the skin of the wearer.
7. A disposable diaper as in Claim 6 wherein the elastic elements are disposed between the facing and backing layer.
8. A disposable diaper as in Claim 7 wherein the elastic elements are secured to both the facing layer and backing layer.
9. A disposable diaper as in Claim 6 wherein the elastic elements in the marginal portion are disposed in parallel relationship one to the other.
10. A disposable diaper comprising: a moisture-permeable facing layer; an absorbent panel at one side of said facing layer, said absorbent panel being smaller than said facing layer so that side marginal portions of the facing layer extend outwardly beyond the side edges of said absorbent panel; a moisture-impervious backing layer at the side of said absorbent panel opposite said facing layer, said backing layer being larger than said absorbent panel so that side marginal portions of the backing layer extend outwardly beyond the side edges of said absorbent panel; means bonding said facing and backing layers to one another; and gathering means disposed in said side marginal portions, each of said gathering means including at least two spaced separate and distinct longitudinally extending, effectively elastic elements secured in each of said side marginal portions, said elastic elements being disposed in parallel relationship one to the other along only a portion of their length, whereby said gathering means provide improved conformity about the legs of the wearer without undue application of pressure upon the skin of the wearer and each of said elastic elements applies a gathering force to a zone of a side marginal portion thereby defining more than one gasketing line at the leg of the wearer for improved liquid containment.
11. A disposable diaper comprising: a moisture-permeable facing layer; an absorbent panel at one side of said facing layer, said absorbent panel being smaller than said facing layer so that side marginal portions of the facing layer extend outwardly beyond the side edges of said absorbent panel; a moisture-impervious backing layer at the side of said absorbent panel opposite said facing layer, said backing layer being larger than said absorbent panel so that side marginal portions of the backing layer extend outwardly beyond the side edges of said absorbent panel; means bonding said facing and backing layers to one another; and gathering means disposed in said side marginal portions, each of said gathering means including at least two spaced separate and distinct longitudinally extending, effectively elastic elements secured in each of said side marginal portions, wherein one of the elastic elements in each side marginal portion has a different degree of elasticity than the other elastic element in said side marginal portion, whereby said gathering means provide improved conformity about the legs of the wearer without undue application of pressure upon the skin of the wearer and each of said elastic elements applies a gathering force to a zone of a side marginal portion thereby defining more than one gasketing line at the leg of the wearer for improved liquid containment.
12. A disposable diaper as in Claim 11 wherein the elastic elements are disposed between the facing layer and the backing layer, and are secured to both the facing layer and backing layer.
13. A disposable diaper as in Claim 11 wherein the elastic elements in each side marginal portion are disposed in parallel relationship one to the other.
14. A disposable diaper as in Claim 11 wherein at least one of the elastic elements in each side marginal portion is disposed parallel to a side edge of the diaper.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BE0/210151A BE895951A (en) | 1983-02-18 | 1983-02-18 | DISPOSABLE LAYER AFTER USE WELL FORMING BODY AND WITH IMPROVED LIQUID RETENTION |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1176401A true CA1176401A (en) | 1984-10-23 |
Family
ID=3862058
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000422735A Expired CA1176401A (en) | 1983-02-18 | 1983-03-02 | Disposable diaper with improved body conformity and liquid retention |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU557776B2 (en) |
| BE (1) | BE895951A (en) |
| CA (1) | CA1176401A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5509915A (en) | 1991-09-11 | 1996-04-23 | Kimberly-Clark Corporation | Thin absorbent article having rapid uptake of liquid |
| US5836930A (en) * | 1993-05-03 | 1998-11-17 | Kimberly-Clark Worldwide, Inc | Absorbent article having an umbilical protection feature and an abbreviated absorbent structure |
-
1983
- 1983-02-08 AU AU11242/83A patent/AU557776B2/en not_active Ceased
- 1983-02-18 BE BE0/210151A patent/BE895951A/en not_active IP Right Cessation
- 1983-03-02 CA CA000422735A patent/CA1176401A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5509915A (en) | 1991-09-11 | 1996-04-23 | Kimberly-Clark Corporation | Thin absorbent article having rapid uptake of liquid |
| US5836930A (en) * | 1993-05-03 | 1998-11-17 | Kimberly-Clark Worldwide, Inc | Absorbent article having an umbilical protection feature and an abbreviated absorbent structure |
Also Published As
| Publication number | Publication date |
|---|---|
| AU557776B2 (en) | 1987-01-08 |
| AU1124283A (en) | 1984-08-16 |
| BE895951A (en) | 1983-08-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEC | Expiry (correction) | ||
| MKEX | Expiry |