U.S. patent application number 14/799658 was filed with the patent office on 2015-11-05 for disposable pull-on garment having improved protection against red marking and method for making the same.
The applicant listed for this patent is The Procter & Gamble Company. Invention is credited to Gregory ASHTON, Kenneth Barclay BUELL, Craig Andrew HAWKINS, William Robert VINNAGE.
Application Number | 20150313767 14/799658 |
Document ID | / |
Family ID | 22267149 |
Filed Date | 2015-11-05 |
United States Patent
Application |
20150313767 |
Kind Code |
A1 |
BUELL; Kenneth Barclay ; et
al. |
November 5, 2015 |
DISPOSABLE PULL-ON GARMENT HAVING IMPROVED PROTECTION AGAINST RED
MARKING AND METHOD FOR MAKING THE SAME
Abstract
The present disclosure is directed, in part, to a disposable
garment having a front region, a back region, and a crotch region
extending between the front region and the back region. The
disposable garment comprises a chassis in the front region, the
back region, and the crotch region. The chassis comprises a liquid
pervious topsheet, a liquid impervious backsheet, and an absorbent
core disposed between the topsheet and the backsheet. The
disposable garment comprises a pair of ear panels extending
laterally outward from the chassis in the front region or the back
region, a seam panel extending laterally outward from at least one
of the ear panels, and a tab formed with the seam panel and
extending laterally outward from the seam panel.
Inventors: |
BUELL; Kenneth Barclay;
(Port Orange, FL) ; ASHTON; Gregory; (Venice,
FL) ; HAWKINS; Craig Andrew; (Mason, OH) ;
VINNAGE; William Robert; (Cincinnati, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Procter & Gamble Company |
Cincinnati |
OH |
US |
|
|
Family ID: |
22267149 |
Appl. No.: |
14/799658 |
Filed: |
July 15, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14268170 |
May 2, 2014 |
9114043 |
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14799658 |
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13599341 |
Aug 30, 2012 |
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14268170 |
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10366176 |
Feb 13, 2003 |
8257334 |
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13599341 |
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09700559 |
Nov 16, 2000 |
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PCT/US1998/010841 |
May 28, 1998 |
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10366176 |
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Current U.S.
Class: |
604/385.16 |
Current CPC
Class: |
A61F 13/5622 20130101;
A61F 13/5655 20130101; A61F 13/496 20130101; A61F 13/49011
20130101; A61F 2013/49087 20130101; A61F 2013/49023 20130101; A61F
13/49012 20130101; A61F 13/4963 20130101; A61F 13/565 20130101;
A61F 2013/49047 20130101; A61F 13/49015 20130101; A61F 2013/49092
20130101 |
International
Class: |
A61F 13/49 20060101
A61F013/49 |
Claims
1. A disposable pull-on diaper comprising: a liquid pervious
topsheet; a liquid impervious backsheet; an absorbent core disposed
between the topsheet and the backsheet; a front region; a back
region; a side; a first extensible ear panel extending outwardly
from the side in the front region, wherein the first extensible ear
panel is a discrete element and is joined to the side, wherein the
first extensible ear panel comprises: a first nonwoven material; a
second nonwoven material; and an apertured film positioned at least
partially intermediate the first and second nonwoven materials; a
second extensible ear panel extending outwardly from the side in
the back region, wherein the second extensible ear panel is a
discrete element and is joined to the side, wherein the second
extensible ear panel comprises: a first nonwoven material; a second
nonwoven material; and an apertured film positioned at least
partially intermediate the first and second nonwoven materials; a
butt seam joining the first and second extensible ear panels to
form a leg opening; an elasticized waistband in the front region; a
first leg cuff; and a second leg cuff; wherein a first portion of
the elasticized waistband overlaps a first portion of the first leg
cuff; and wherein a second portion of the elasticized waistband
overlaps a first portion of the second leg cuff.
2. The pull-on diaper of claim 1, wherein the butt seam comprises a
pattern of heat or pressure welds.
3. The pull-on diaper of claim 1, wherein the butt seam comprises a
pattern of ultrasonic welds.
4. The pull-on diaper of claim 1, comprising a second side, and
wherein the pull-on diaper comprises: a third extensible ear panel
extending outwardly from the second side in the front region,
wherein the third extensible ear panel is a discrete element and is
joined to the second side, and wherein the third extensible ear
panel comprises: a first nonwoven material; a second nonwoven
material; and an apertured film positioned at least partially
intermediate the first and second nonwoven materials; a fourth
extensible ear panel extending outwardly from the second side in
the back region, wherein the fourth extensible ear panel is a
discrete element and is joined to the second side, and wherein the
fourth extensible ear panel comprises: a first nonwoven material; a
second nonwoven material; and an apertured film positioned at least
partially intermediate the first and second nonwoven materials; and
a second butt seam joining the third and fourth extensible ear
panels to form a second leg opening.
5. The pull-on diaper of claim 4, wherein the second butt seam
comprises a pattern of heat or pressure welds.
6. The pull-on diaper of claim 4, wherein the second butt seam
comprises a pattern of ultrasonic welds.
7. The pull-on diaper of claim 1, comprising a second elasticized
waistband in the back region.
8. The pull-on diaper of claim 7, wherein a first portion of the
second elasticized waistband overlaps a second portion of the first
leg cuff, and wherein a second portion of the second elasticized
waistband overlaps a second portion of the second leg cuff.
9. The pull-on diaper of claim 7, wherein a portion of the
elasticized waistband overlaps a portion of the first extensible
ear panel, and wherein a portion of the second elasticized
waistband overlaps a portion of the second extensible ear
panel.
10. The pull-on diaper of claim 1, wherein a portion of the
backsheet overlaps with a portion of the first extensible ear
panel.
11. The pull-on diaper of claim 1, wherein a portion of the
backsheet extends into the first extensible ear panel.
12. The pull-on diaper of claim 11, wherein a portion of the
backsheet extends into the second extensible ear panel.
13. The pull-on diaper of claim 12, wherein the first portion of
the first leg cuff overlaps a portion of the first extensible ear
panel.
14. A disposable diaper comprising: a liquid pervious topsheet; a
liquid impervious backsheet; an absorbent core disposed between the
topsheet and the backsheet; a front region; a back region; and a
side; a discrete first ear panel extending outwardly from the side
in the front region, wherein the first ear panel comprises: a first
nonwoven material; a second nonwoven material; and a perforated
film positioned at least partially intermediate the first and
second nonwoven materials; a discrete second ear panel extending
outwardly from the side in the back region, wherein the second ear
panel comprises: a first nonwoven material; a second nonwoven
material; and a perforated film positioned at least partially
intermediate the first and second nonwoven materials; a butt seam
joining the discrete first and second ear panels to form a leg
opening; and an elasticized waistband on a wearer-facing surface of
the diaper; wherein a portion of the elasticized waistband overlaps
either a portion of the discrete first ear panel or a portion of
the discrete second ear panel; and wherein a portion of the
elasticized waistband overlaps a portion of a leg cuff, and wherein
the portion of the leg cuff overlaps either a portion of the
discrete first ear panel or a portion of the discrete second ear
panel.
15. The diaper of claim 14, wherein the butt seam comprises a
pattern of heat or pressure welds or a pattern of ultrasonic
welds.
16. The diaper of claim 14, comprising a second elasticized
waistband on a wearer-facing surface of the diaper.
17. The diaper of claim 14, comprising a second side, and wherein
the diaper comprises: a discrete third ear panel extending
outwardly from the second side in the front region, wherein the
third ear panel comprises: a first nonwoven material; a second
nonwoven material; and a perforated film positioned at least
partially intermediate the first and second nonwoven materials; a
discrete fourth ear panel extending outwardly from the second side
in the back region, wherein the fourth ear panel comprises: a first
nonwoven material; a second nonwoven material; and a perforated
film positioned at least partially intermediate the first and
second nonwoven materials; and a second butt seam joining the
discrete third and fourth extensible ear panels to form a second
leg opening; and a second elasticized waistband on the
wearer-facing surface of the diaper.
18. The diaper of claim 17, wherein the second butt seam comprises
a pattern of heat or pressure welds or a pattern of ultrasonic
welds.
19. The diaper of claim 14, wherein a portion of the liquid
impervious backsheet extends to a portion of the first ear
panel.
20. The diaper of claim 14, wherein a portion of the liquid
impervious backsheet overlaps with a portion of the first ear
panel.
21. The diaper of claim 17, wherein the discrete first and third
ear panels have substantially the same size and shape.
22. The diaper of claim 17, wherein the discrete second and fourth
ear panels have substantially the same size and shape.
23. The diaper of claim 14, comprising an acquisition/distribution
core positioned over the absorbent core.
24. The diaper of claim 14, comprising a second leg cuff, wherein
the elasticized waistband overlaps a portion of the second leg
cuff.
25. A disposable pull-on diaper comprising: a liquid pervious
topsheet; a liquid impervious backsheet; an absorbent core disposed
between the topsheet and the backsheet; a front region; a back
region; a side; a first extensible ear panel extending outwardly
relative to the side in the front region, wherein the first
extensible ear panel is a discrete element and is joined to the
side, wherein the first extensible ear panel comprises: a first
nonwoven material; a second nonwoven material; and an apertured or
perforated material positioned at least partially intermediate the
first and second nonwoven materials; a second extensible ear panel
extending outwardly relative to the side in the back region,
wherein the second extensible ear panel is a discrete element and
is joined to the side, wherein the second extensible ear panel
comprises: a first nonwoven material; a second nonwoven material;
and an apertured or perforated material positioned at least
partially intermediate the first and second nonwoven materials; and
a butt seam joining the first and second extensible ear panels to
form a leg opening; a first elasticized waistband in the front
region; and a second elasticized waistband in the back region;
wherein a portion of the backsheet extends to the first extensible
ear panel; and wherein a portion of the backsheet extends to the
second extensible ear panel.
26. The pull-on diaper of claim 25, wherein a portion of the first
elasticized waistband overlaps a portion of the first extensible
ear panel, and wherein a portion of the second elasticized
waistband overlaps a portion of the second extensible ear
panel.
27. The pull-on diaper of claim 25, comprising a leg cuff, wherein
a portion of the first elasticized waistband overlaps a portion of
the leg cuff.
28. The pull-on diaper of claim 27, comprising a second leg cuff,
wherein a portion of the second elasticized waistband overlaps a
portion of the second leg cuff.
29. A disposable pull-on diaper comprising: a topsheet; a
backsheet; an absorbent core disposed between the topsheet and the
backsheet; a front region; a back region; a side; a discrete first
extensible ear panel extending outwardly from the side in the front
region, wherein the discrete first extensible ear panel is joined
to the side, wherein the first extensible ear panel comprises: a
first nonwoven material; a second nonwoven material; and an
apertured or perforated material positioned at least partially
intermediate the first and second nonwoven materials; a discrete
second extensible ear panel extending outwardly from the side in
the back region, wherein the discrete second extensible ear panel
is joined to the side, wherein the second extensible ear panel
comprises: a first nonwoven material; a second nonwoven material;
and an apertured or perforated material positioned at least
partially intermediate the first and second nonwoven materials; a
butt seam comprising a plurality of bonds joining the discrete
first and second extensible ear panels to form a leg opening; and
an elasticized waistband on a wearer-facing surface of the diaper,
wherein the elasticized waistband overlaps a portion of the
discrete first extensible ear panel or a portion of the discrete
second extensible ear panel; wherein the backsheet extends to the
first extensible ear panel.
30. The pull-on diaper of claim 29, wherein the elasticized
waistband is in the front region, and wherein a portion of the
elasticized waistband overlaps a first portion of a leg cuff.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/268,170, filed on May 2, 2014, which is a
continuation of U.S. patent application Ser. No. 13/599,341, filed
on Aug. 30, 2012, which is a continuation of U.S. patent
application Ser. No. 10/366,176, filed on Feb. 13, 2003, now U.S.
Pat. No. 8,257,334, which is a divisional of U.S. patent
application Ser. No. 09/700,559, filed on Nov. 16, 2000, now
abandoned, which was the National Stage Entry of International
Application Serial No. PCT/US98/10841, filed on May 28, 1998, the
entire disclosures of each are hereby incorporated by reference in
their entirety.
FIELD
[0002] The present invention relates to disposable garments.
BACKGROUND
[0003] Infants and other incontinent individuals wear disposable
garments such as diapers to receive and contain urine and other
body exudates. Disposable pull-on garments having fixed sides,
which are also called "pant type" garments, have become popular for
use on children able to walk and often who are toilet training
These pull-on garments have side panels with edges that are seamed
together to form two leg openings and a waist opening. In order to
contain body exudates as well as fit a wide variety of body shapes
and sizes, these pull-on garments need to fit snugly about the
waist and legs of the wearer without drooping, sagging or sliding
down from its position on the torso. Examples of these pull-on
garments are disclosed, for example, in U.S. Pat. No. 5,171,239
issued to Igaue et al. on Dec. 15; 1992, U.S. Pat. No. 4,610,681
issued to Strohbeen et al. on Sep. 9, 1986; U.S. Pat. No. 4,940,464
issued to Van Gompel et al. on Jul. 10, 1990; U.S. Pat. No.
5,246,433 to issued Hasse et al. on Sep. 21, 1993; U.S. Pat. No.
5,569,234 issued to Buell et al. on Oct. 29, 1996; and WO 96/31176
(Ashton) published on Oct. 10, 1996.
[0004] To prevent pull-on garments from drooping, sagging or
sliding down from the torso of wearer, it is believed that a proper
force should be generated at the waist and side panel areas of
pull-on garments and applied to the torso of the wearer. For
example, U.S. Pat. No. 5,415,649 issued to Watanabe et al. on May
16, 1995, discloses the use of elastic members which have different
expanding stresses to provide a better fit to body. Another example
is EP 0547497B1 (Van Gompel et al.) published on Mar. 26, 1997.
This publication discloses a disposable training pant which has
stretch gradient side panels to provide an improved fitness. Those
conventional pull-on garments try to provide an improved fitness to
the body of wearer by controlling forces applied to the waist and
leg areas of wearer. However, the improvement in fitness may cause
a red marking problem at those areas.
[0005] Japanese Laid-Open Patent Publication H8-38546 published on
Feb. 13, 1996 discloses a pant type disposable diaper which has a
slit formed by not connecting leg portion elastics at the leg
opening, to prevent marking of the skin by the leg portion
elastics. However, this pull-on garment has a unextensible
backsheet in the side panels, which tends to prevent the pull-on
garment from providing an improved fitness.
[0006] Thus, none of the existing art provides all of the
advantages and benefits of the present invention.
SUMMARY
[0007] In an embodiment, the present disclosure is directed, in
part, to a disposable garment having a front region, a back region,
and a crotch region extending between the front region and the back
region. The disposable garment comprises a chassis in the front
region, the back region, and the crotch region. The chassis
comprises a liquid pervious topsheet, a liquid impervious
backsheet, and an absorbent core positioned between the topsheet
and the backsheet. The disposable garment further comprises a pair
of extensible ear panels extending laterally outward from the
chassis in the front region or the back region, wherein the liquid
impervious backsheet does not extend to the extensible ear
panels.
[0008] In another embodiment, the present disclosure is directed,
in part, to a disposable garment having a front region, a back
region, and a crotch region extending between the front region and
the back region. The disposable garment comprises a chassis in the
front region, the back region, and the crotch region. The chassis
comprises a liquid pervious topsheet, a liquid impervious
backsheet, and an absorbent core positioned between the topsheet
and the backsheet. The disposable garment comprises a pair of
extensible ear panels extending laterally outward from the chassis
in the front region or the back region, wherein the liquid
impervious backsheet is separate from the extensible ear
panels.
[0009] In still another embodiment, the present disclosure is
directed, in part, to a laminate structure comprising a first
coverstock layer, a second coverstock layer, an elastomeric
material positioned intermediate the first coverstock layer and the
second coverstock layer, a first anchor zone comprising a first
bonding pattern positioned in a first edge area of the laminate
structure, a second anchor zone comprising the first bonding
pattern positioned in a second edge area of the laminate structure,
and a second bonding pattern intermediate the first and second
anchor zones.
[0010] In yet another embodiment, the present disclosure is
directed, in part, to a disposable garment having a front region, a
back region, and a crotch region extending between the front region
and the back region. The disposable garment comprises a chassis in
the front region, the back region, and the crotch region. The
chassis comprises a liquid pervious topsheet, a liquid impervious
backsheet, and an absorbent core disposed between the topsheet and
the backsheet. The disposable garment comprises a pair of ear
panels extending laterally outward from the chassis in the front
region or the back region, a seam panel extending laterally outward
from at least one of the ear panels, and a tab formed with the seam
panel and extending laterally outward from the seam panel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] While the specification concludes with claims particularly
pointing out and distinctly claiming the invention, it is believed
that the invention will be better understood from the following
description of preferred embodiments which is taken in conjunction
with the accompanying drawings and which like designations are used
to designate substantially identical elements, and in which:
[0012] FIG. 1 is a perspective view of one preferred embodiment of
the disposable pull-on garment of the present invention in a
typical in use configuration;
[0013] FIG. 2 is a perspective view of another preferred embodiment
of the disposable pull-on garment of the present invention in a
typical in use configuration;
[0014] FIG. 2A is a perspective view of another preferred
embodiment of the disposable pull-on garment of the present
invention in a typical use configuration;
[0015] FIG. 2B is a perspective view of another preferred
embodiment of the disposable pull-on garment of the present
invention in a typical use configuration;
[0016] FIG. 3 is a simplified plan view of the embodiment shown in
FIG. 2 in its flat uncontracted condition showing the various
panels or zones of the garment;
[0017] FIG. 4 is a cross-sectional view of a preferred embodiment
taken along the section line 4-4 of FIG. 3;
[0018] FIG. 5 is a more detailed plan view of the front and back
ear panels 46 and 48 which are shown in FIG. 2;
[0019] FIG. 6 is a cross-sectional view of an elastic member 70 of
a preferred embodiment;
[0020] FIG. 7 is a fragmentary enlarged side view of the elastic
member 70 shown in FIG. 4;
[0021] FIG. 8 is a graph showing the two-cycles of hysteresis
curves of an elastomeric material, in a preferred embodiment;
[0022] FIG. 9 is a fragmentary enlarged perspective illustration of
an alternative embodiment of the elastomeric material; and
[0023] FIG. 10 is a plan view of one embodiment of the front ear
panel 46.
DETAILED DESCRIPTION
[0024] All cited references are incorporated herein by reference in
their entireties. Citation of any reference is not an admission
regarding any determination as to its availability as prior art to
the claimed invention.
[0025] Herein, "pull-on garment" refers to articles of wear which
have a defined waist opening and a pair of leg openings and which
are pulled onto the body of the wearer by inserting the legs into
the leg openings and pulling the article up over the waist. Herein,
"disposable" describes garments which are not intended to be
laundered or otherwise restored or reused as a garment (i.e., they
are intended to be discarded after a single use and, preferably, to
be recycled, composted or otherwise disposed of in an
environmentally compatible manner). A "unitary" pull-on garment
refers to pull-on garments which are formed of separate parts
united together to form a coordinated entity, but the ear panels
are not separate elements joined to a separate chassis; rather, the
ear panels are formed by at least one layer which also forms the
chassis of the garment (i.e., the garment does not require
separately manipulative panels such as a separate chassis and
separate ear panels). The pull-on garment is also preferably
"absorbent" to absorb and contain the various exudates discharged
from the body. A preferred embodiment of the pull-on garment of the
present invention is the unitary disposable absorbent pull-on
garment, pull-on garment 120, shown in FIG. 1. Herein, "pull-on
diaper" refers to pull-on garments generally worn by infants and
other incontinent individuals to absorb and contain urine and
feces. It should be understood, however, that the present invention
is also applicable to other pull-on garments such as training
pants, incontinent briefs, feminine hygiene garments or panties,
and the like. Herein, "panel" denotes an area or element of the
pull-on garment. (While a panel is typically a distinct area or
element, a panel may coincide (functionally correspond) somewhat
with an adjacent panel.) Herein, "joined" or "joining" encompasses
configurations whereby an element is directly secured to another by
affixing the element directly to the other element, and
configurations whereby the element is indirectly secured to the
other element by affixing the element to intermediate member(s)
which in turn are affixed to the other element. Herein,
"uncontracted state" is used herein to describe states of pull-on
garments in its unseamed (i.e., seams are removed), flat and
relaxed condition wherein all elastic materials used are removed
therefrom.
[0026] FIG. 1 shows one preferred embodiment of a disposable
pull-on garment of the present invention (i.e., a unitary
disposable pull-on diaper 120). Referring to FIG. 1, the disposable
pull-on garment 120 of the present invention has a front region 26;
a back region 28 and a crotch region 30 between the front region 26
and the back region 28. A chassis 41 is provided in the front, back
and crotch regions 26, 28 and 30. The chassis 41 includes a liquid
pervious topsheet 24, a liquid impervious backsheet 22 associated
with the topsheet 24, and an absorbent core 25 (not shown in FIG.
1) disposed between the topsheet 24 and the backsheet 22. The
chassis 41 has side edges 220 which form edge lines 222 in the
front region 26.
[0027] The pull-on garment 120 of the invention further includes at
least one pair of extensible ear panels 45 each extending laterally
outward from the corresponding sides of the chassis 41. Each of the
ear panels 45 has an outermost edge 240 which forms an outermost
edge line 242. At least one of the outermost edge lines 242 has a
nonuniform lateral distance from the longitudinal center line 100
(not shown in FIG. 1) in the uncontracted state of the garment
120.
[0028] In a preferred embodiment, the ear panels 45 continuously
extend from the corresponding sides of the chassis 41 in the back
region 28 to the corresponding side edges 220 of the chassis 41 in
the front region 26 as shown in FIG. 1. Alternatively, the ear
panels 45 may continuously extend from the corresponding sides of
the chassis 41 in the front region 26 to the corresponding side
edges of the chassis 41 in the back region 28 (not shown in FIG.
1).
[0029] The pull-on garment 120 of the invention has the ear panels
45 joined to the chassis 41 to form two leg openings 34 and a waist
opening 36. Preferably, the pull-on garment 120 further includes
seams 232 each joining the chassis 41 and the ear panels 45 along
the corresponding edge lines 222 and 242 to form the two leg
openings 34 and the waist opening 36.
[0030] In a preferred embodiment, at least one of the ear panels 45
having, along the seam 232, a substantially bonded portion SB
starting from the waist opening 36 and an unbonded portion UB
starting from the leg opening 34. Preferably, the ratio in length
of the unbonded portion to the substantially bonded portion is
between about 4:96 and 20:80.
[0031] FIG. 2 shows another preferred embodiment of a disposable
pull-on garment of the present invention (i.e., a unitary
disposable pull-on diaper 20). Referring to FIG. 2, the disposable
pull-on garment 20 includes a pair of extensible front ear panels
46 each extending laterally outward from the corresponding sides of
the chassis 41 in the front region 26, and a pair of extensible
back ear panels 48 each extending laterally outward from the
corresponding sides of the chassis 41 in the back region 28. Each
of the ear panels 46 and 48 has an outermost edge 240 which forms
an outermost edge line 242. At least one of the outermost edge
lines 242 has a nonuniform lateral distance from the longitudinal
center line 100 (not shown in FIG. 2 but in FIG. 3) in the
uncontracted state of the garment 20. The pull-on garment 20
further includes seams 32 each joining the front and back ear
panels 46 and 48 along the corresponding edge lines 242 to form the
two leg openings 34 and the waist opening 36.
[0032] In a preferred embodiment, at least one of, more preferably
both of, the pairs of the ear panels 45, 46 and 48 are elastically
extensible in at least the lateral direction. In alternative
embodiments, the ear panels 45, 46 and 48 are elastically
extensible both in the lateral and longitudinal directions. Herein,
"extensible" refers to materials that are capable of extending in
at least one direction to a certain degree without undue rupture.
Herein, "elasticity" and "elastically extensible" refer to
extensible materials that have the ability to return to
approximately their original dimensions after the force that
extended the material is removed. Herein, any material or element
described as "extensible" may also be elastically extensible unless
otherwise provided. The extensible ear panels 45, 46 and 48 provide
a more comfortable and contouring fit by initially conformably
fitting the pull-on garment to the wearer and sustaining this fit
throughout the time of wear well past when the pull-on garment has
been loaded with exudates since the ear panels 45, 46 and/or 48
allow the sides of the pull-on garment to expand and contract.
[0033] The ear panels 45, 46 and 48 may be formed by unitary
elements of the pull-on garment 20 or 120 (i.e., they are not
separately manipulative elements secured to the pull-on garment 20
or 120, but rather are formed from and are extensions of one or
more of the various layers of the pull-on garment). In a preferred
embodiment, each of the ear panels 45, 46 and 48 is a projected
member of the chassis 41 (more clearly shown in FIG. 3).
Preferably, the ear panels 45, 46 and 48 include at least one
unitary element or a continuous sheet material (e.g. the nonwoven
outer cover 74 in FIG. 4) that forms a part of the chassis 41 and
continuously extends into the ear panels 45, 46 and 48.
Alternatively, the ear panels 45, 46 and 48 may be discrete members
(shown in FIGS. 2, 2A, and 2B using dashed lines) which do not have
any unitary element that forms a part of the chassis 41, and may be
formed by joining the discrete members to the corresponding sides
of the chassis 41.
[0034] In a preferred embodiment, the pull-on garment 20 or 120
further includes seam panels 66 each extending laterally outward
from each of the ear panels 45, 46 and 48; and tear open tabs 31
each extending laterally outward from the seam panel 66. In a
preferred embodiment, each of the seam panels 66 is an extension of
the corresponding ear panels 45, 46 and 48, or at least one of the
component elements used therein, or any other combination of the
elements. More preferably, each of the tear open tabs 31 is also an
extension of the corresponding seam panel 66 or at least one of its
component elements used therein, or any other combination of its
elements.
[0035] The tear open tab 31 can take any shape as long as it
facilitates intentional tearing open at the seams 32 after soiling
of the pull-on garments 20 and 120. In a preferred embodiment, the
lateral distance LD from the longitudinal center line 100 increases
towards the leg opening 34 as shown in FIG. 10. In this embodiment,
the original material to be used for the front ear panel has a
shape defined by the upper material line 154 and the side material
line 156 which is perpendicular to the upper material line 154. The
outer most edge 240 and the tear open tab 31 are formed by removing
(or cutting out) the edge portions 158 from the original material.
Since the tear open tab 31 can be obtained within the original
material which has the right angle defined by the lines 154 and
156, an effective material use can be achieved (i.e., the original
ear panel material can be used effectively).
[0036] In a preferred embodiment, the corresponding edge portions
of the chassis 41 and/or the ear panels 45, 46 and 48 are seamed
directly or indirectly (e.g., through the seam panels 66), in an
overlapping manner to make an overlapped seam structure.
Alternatively, the front and ear panels 46 and 48 can be seamed in
a butt seam manner (shown in FIGS. 2A and 2B). The bonding of the
seams 32 can be performed by any suitable means known in the art
appropriate for the specific materials employed in the chassis 41
and/or the ear panels 45, 46 and 48. Thus, sonic sealing, heat
sealing, pressure bonding, adhesive or cohesive bonding, sewing,
autogeneous bonding, and the like may be appropriate techniques.
Preferably, the seam panels 66 are joined by a predetermined
pattern of heat/pressure or ultrasonic welds which withstands the
forces and stresses generated on the garment 20 or 120 during
wear.
[0037] A continuous belt 38 is formed by the ear panels 45, 46 and
48, and a part of the chassis 41 about the waist opening 36 as
shown in FIGS. 1 and 2. Preferably, elasticized waist bands 50 are
provided in both the front region 26 and the back region 28. The
continuous belt 38 acts to dynamically create fitment forces in the
pull-on garment 20 or 120 when positioned on the wearer, to
maintain the pull-on garment 20 or 120 on the wearer even when
loaded with body exudates thus keeping the absorbent core 25 (not
shown in FIG. 2) in close proximity to the wearer, and to
distribute the forces dynamically generated during wear about the
waist thereby providing supplemental support for the absorbent core
25 without binding or bunching the absorbent core 25.
[0038] FIG. 3 is a partially cut-away plan view of the pull-on
garment 20 of FIG. 2 in its uncontracted state (except in the ear
panels 46 and 48 which are left in their relaxed condition) with
the topsheet 24 facing the viewer, prior to the ear panels 46 and
48 being joined together by the seams 32. The pull-on garment 20
has the front region 26, the back region 28 opposed to the front
region 26, the crotch region 30 positioned between the front region
26 and the back region 28, and a periphery which is defined by the
outer perimeter or edges of the pull-on garment 20 in which the
side edges are designated 150 and 240, and the end edges or waist
edges are designated 152. The topsheet 24 has the body-facing
surface of the pull-on garment 20 which is positioned adjacent to
the wearer's body during use. The backsheet 22 has the outer-facing
surface of the pull-on garment 20 which is positioned away from the
wearer's body. The pull-on garment 20 includes the chassis 41
including the liquid pervious topsheet 24, the liquid impervious
backsheet 22 associated with the topsheet 24, and the absorbent
core 25 positioned between the topsheet 24 and the backsheet 22.
The garment 20 further includes the front and back ear panels 46
and 48 extending laterally outward from the chassis 41, the
elasticized leg cuffs 52, and the elasticized waistbands 50. The
topsheet 24 and the backsheet 22 have length and width dimensions
generally larger than those of the absorbent core 25. The topsheet
24 and the backsheet 22 extend beyond the edges of the absorbent
core 25 to thereby form the side edges 150 and the waist edges 152
of the garment 20. The liquid impervious backsheet 22 preferably
includes a liquid impervious plastic film 68.
[0039] The pull-on garment 20 also has two centerlines, a
longitudinal centerline 100 and a transverse centerline 110.
Herein, "longitudinal" refers to a line, axis, or direction in the
plane of the pull-on garment 20 that is generally aligned with
(e.g. approximately parallel with) a vertical plane which bisects a
standing wearer into left and right halves when the pull-on garment
20 is worn. Herein, "transverse" and "lateral" are interchangeable
and refer to a line, axis or direction which lies within the plane
of the pull-on garment that is generally perpendicular to the
longitudinal direction (which divides the wearer into front and
back body halves). The pull-on garment 20 and component materials
thereof also have a body-facing surface which faces the skin of
wearer in use and an outer-facing surface which is the opposite
surface to the body-facing surface.
[0040] Each of the ear panels 45, 46 and 48 of the present
invention has the outermost edge line 242. Herein, "edge line"
refers to lines which define the outlines of the ear panels 45, 46
and 48 or the chassis 41. Herein, "outermost" refers to portions
which are farthest from the longitudinal centerline 100. At least
one of the edge lines 242 has a nonuniform lateral distance LD from
the longitudinal center line 100 in the uncontracted state of the
garment 20.
[0041] In a preferred embodiment, the outermost edge line 242 has a
first point 251 at the closest portion to the waist opening 36 and
a second point 252 at the closest portion to the leg opening 34,
and the outermost edge line 242 is a straight line defined by
connecting the first and second points 251 and 252. The outermost
edge line 242 shows the direction of the outermost edge 240 of the
ear panel. In a preferred embodiment, the edge line 242 leans to
the longitudinal center line 100 in the uncontracted state of the
pull-on garment 20. More preferably, the outermost edge line 242
has, in the uncontracted state of the pull-on garment 20, a lateral
distance LD from the longitudinal center line 100 which increases
towards the leg opening 34 as shown in FIG. 3. Alternatively, the
outermost edge line 242 may have, in the uncontracted state of the
pull-on garment 20, a lateral distance LD from the longitudinal
center line 100 which decreases towards the leg opening 34 (not
shown in Figs.).
[0042] While the topsheet 24, the backsheet 22, and the absorbent
core 25 may be assembled in a variety of well known configurations,
exemplary chassis configurations are described generally in U.S.
Pat. No. 3,860,003 entitled "Contractible Side Portions for
Disposable Diaper" which issued to Kenneth B. Buell on Jan. 14,
1975; and U.S. Pat. No. 5,151,092 entitled "Absorbent Article With
Dynamic Elastic Waist Feature Having A Predisposed Resilient
Flexural Hinge" which issued to Kenneth B. Buell et al., on Sep.
29, 1992.
[0043] FIG. 4 is a cross-sectional view of a preferred embodiment
taken along the section line 4-4 of FIG. 3. The pull-on garment 20
includes the chassis 41 including the liquid pervious topsheet 24,
the liquid impervious backsheet 22 associated with the topsheet 24,
and the absorbent core 25 positioned between the topsheet 24 and
the backsheet 22. The pull-on garment further includes the front
ear panels 46 each extending laterally outward from the chassis 41,
and an inner barrier cuffs 54. Although FIG. 4 depicts only the
structure of the front ear panel 46 and the chassis 41 in the front
region 26, preferably a similar structure is also provided in the
back region 28. In a preferred embodiment, each of the front ear
panels 46 is formed by a lamination of an extended part 72 of the
barrier flap 56, an elastic member 70 and the nonwoven outer cover
74. The elastic member 70 includes a plane elastomeric material 124
(not shown in FIG. 4 but in FIG. 6). Herein, "plane elastomeric
material" refers to elastomeric materials which continuously extend
in two dimensional directions. Preferred plane elastomeric
materials include a scrim, a perforated (or apertures formed) film,
an elastomeric woven or nonwoven, and the like. In a preferred
embodiment, the plane elastomeric material 124 includes at least a
portion that has a nonuniform lateral width.
[0044] FIG. 5 is a more detailed plan view of the front and back
ear panels 46 and 48 shown in FIG. 2. In FIG. 5, the nonwoven outer
cover 74 is removed from the ear panels 46 and 48 to clearly show
the elastic members 70 and the seam 32. In a preferred embodiment,
each of the ear panels 46 and 48 includes the elastic member 70
which includes a plane elastomeric material 124 (such as the one
shown in FIG. 6). The elastic member 70 may further include an
extensible sheet or film material (e.g., a nonwoven material) which
is joined to the plane elastomeric material 124.
[0045] In a preferred embodiment, the plane elastomeric material
124 has an identical shape and dimensions with the elastic member
70. The elastic member 70 and the plane elastomeric material 124
may take a wide variety of sizes and shapes (e.g., triangular,
rectangular, other quadrilateral, and other polygon). In a
preferred embodiment, the plane elastomeric material 124 has at
least a portion that has a nonuniform lateral width LW. Preferably,
the lateral width LW of the plane elastomeric material 124
increases towards the leg opening 34 as shown in FIG. 5.
Alternatively, the lateral width LW of the plane elastomeric
material 124 may decrease towards the leg opening 34 (not shown in
Figs.).
[0046] In a preferred embodiment, the seam 32 is formed on a
seaming line 230 which is preliminary determined along the edge
lines 242. The seaming line 230 can be determined from any straight
lines which may be drawn in the overlapped area 238 between the
edge lines 242. More preferably, the seaming line 230 is formed
along, more preferably in parallel with, the corresponding edge
lines 242. In a more preferred embodiment, a straight line which
equally divides the overlapped area 238 is chosen as the seaming
line 230 as shown in FIG. 5.
[0047] In a preferred embodiment, the seaming line 230 leans to the
longitudinal center line 100 in the uncontracted state of the
garment 20. Preferably, the lateral distance of the seaming line
230 from the longitudinal center line 100 increases toward the leg
opening 34. Alternatively, the lateral distance of the seaming line
230 from the longitudinal center line 100 decreases toward the leg
opening 34 (not shown in Figs.).
[0048] A preferred seam 32 is formed by a plurality of discrete
spaced apart seaming bonds 236 which are formed on the seaming line
230 as shown in FIG. 5. The discrete seaming bonds 236 form, on the
seaming line 230, a substantially bonded portion SB starting from
the waist opening 36 and an unbonded portion UB starting from the
leg opening 34. Herein, "substantially bonded portion" refers to
portions which are intermittently and/or continuously joined to
other materials to contribute to the formation of the leg and waist
openings 34 and 36. Herein, "unbonded portion" refers to portions
which are not joined to other materials.
[0049] In an alternative embodiment, the seam 32 may be formed by a
continuous bond which continuously bonds the front and back ear
panels 46 and 48 on the seaming line 230 (not shown in Figs.). The
continuous bond also forms, on the seaming line 230, a
substantially bonded portion SB starting from the waist opening 36
and an unbonded portion UB starting from the leg opening 34.
[0050] To avoid a red marking problem on wearer's skin, the
preferred ratio in length of the unbonded portion UB to the
substantially bonded portion SB is from about 4:96 to about 20:80,
more preferably from about 8:92 to about 15:85, yet more preferably
from about 10:90 to about 13:87. Preferred disposable pull-on
garments for infants have an unbonded portion UB from the leg
opening 34, in length, from about 4 mm to about 20 mm, more
preferably from about 8 mm to about 15 mm, yet more preferably from
about 10 mm to about 13 mm.
[0051] In a preferred embodiment, at least one of the ear panels
45, 46 and 48 is partially shaped to form a tear open tab 231
associated with the unbonded portion UB for an easy tear open after
soiling. The tear open tab 231 can take any shape as long as it
facilitates intentional tearing open at the seams 32. In this
embodiment, the ear panels 45, 46 and 48 can be torn open from the
leg opening 34 after soiling. Thus, the original tear open tab 31
can be eliminated in this embodiment.
[0052] The method for making a disposable pull-on garment 20 or 120
of the present invention includes the step of preparing the chassis
41 provided in the front, back and crotch regions 26, 28, and 30
and having edge lines 222 in the front and back regions 26 and 28.
The method further includes the step of joining each of the ear
panels 45, 46 and 48 to the chassis 41 along the corresponding edge
lines 222 and 242 to form a seam 32 and 232, thereby forming two
leg openings 34 and a waist opening 36, so that at least one of the
ear panels 45, 46 and 48 has, along the seam 32, the substantially
bonded portion SB starting from the waist opening 36 and the
unbonded portion UB starting from the leg opening 34. The ratio in
length of the unbonded portion UB to the substantially bonded
portion SB is between about 4:96 and about 20:80.
[0053] The absorbent core 25 can be any absorbent member which is
generally compressible, conformable, non-irritating to the wearer's
skin, and capable of absorbing and retaining liquids such as urine
and other certain body exudates. The absorbent core 25 may be
manufactured in a wide variety of sizes and shapes (e.g.,
rectangular, hourglass, "T"-shaped, asymmetric, etc.) and from a
wide variety of liquid-absorbent materials commonly used in
disposable pull-on garments and other absorbent articles such as
comminuted wood pulp which is generally referred to as airfelt.
Examples of other suitable absorbent materials include creped
cellulose wadding; meltblown polymers including coform; chemically
stiffened, modified or cross-linked cellulosic fibers; tissue
including tissue wraps and tissue laminates; absorbent foams;
absorbent sponges; superabsorbent polymers; absorbent gelling
materials; or any equivalent material or combinations of
materials.
[0054] In a preferred embodiment of the invention, the absorbent
core 25 has, in the uncontracted state of the pull-on garment 20,
an area ratio of the core area to the garment area of greater than
about 25%, more preferably greater than about 40%. The core area is
defined as the total area of the body-facing surface of the
absorbent core 25 in the uncontracted state of the pull-on garment
20. The periphery of the body-facing surface of the absorbent core
25 is determined by the outline of aggregates of primary absorbent
materials used in the absorbent core 25. Herein, "primary absorbent
material" refers to absorbent materials which occupy more than
about 80% in dry state volume of the absorbent core 25. In a
preferred embodiment, a wood pulp (e.g., airfelt) is considered a
primary absorbent material of the absorbent core 25 and defines the
periphery of the body-facing surface of the absorbent core 25, thus
defining the core area of the absorbent core 25. The other primary
absorbent materials may include creped cellulose wadding; meltblown
polymers including coform; chemically stiffened, modified or
cross-linked cellulosic fibers; tissue including tissue wraps and
tissue laminates; absorbent foams; absorbent sponges;
superabsorbent polymers; absorbent gelling materials; or any
equivalent material or combinations of materials.
[0055] The garment area is defined as the total area of the
body-facing surface of the pull-on garment 20 in the uncontracted
state. Therefore, the area ratio is calculated as follows:
AR=CA/GA.times.100
wherein, [0056] AR: the area ratio (%) [0057] CA: the core area
(cm.sup.2) [0058] GA: the total area (cm.sup.2)
[0059] In a preferred embodiment for infant use, the absorbent core
25 has a core area of less than about 450 cm.sup.2, more preferably
less than about 425 cm.sup.2. Preferably, the absorbent core 25 has
a maximum core width of less than about 12 cm, more preferably less
than about 11 cm. Herein, "core width" refers to the lateral
distance from one side edge to the other side edge of the absorbent
core 25.
[0060] The configuration and construction of the absorbent core 25
may vary (e.g., the absorbent core 25 may have varying caliper
zones, a hydrophilic gradient, a superabsorbent gradient, or lower
average density and lower average basis weight acquisition zones;
or may include one or more layers or structures). Further, the size
and absorbent capacity of the absorbent core 25 may also be varied
to accommodate wearers ranging from infants through adults.
However, the total absorbent capacity of the absorbent core 25
should be compatible with the design loading and the intended use
of the garment 20.
[0061] A preferred embodiment of the garment 20 has an asymmetric,
modified hourglass-shaped absorbent core 25 having ears in the
front and back waist regions 26 and 28. Other exemplary absorbent
structures for use as the absorbent core 25 that have achieved wide
acceptance and commercial success are described in U.S. Pat. No.
4,610,678 entitled "High-Density Absorbent Structures" issued to
Weisman et al. on Sep. 9, 1986; U.S. Pat. No. 4,673,402 entitled
"Absorbent Articles With Dual-Layered Cores" issued to Weisman et
al. on Jun. 16, 1987; U.S. Pat. No. 4,888,231 entitled "Absorbent
Core Having A Dusting Layer" issued to Angstadt on Dec. 19, 1989;
and U.S. Pat. No. 4,834,735, entitled "High Density Absorbent
Members Having Lower Density and Lower Basis Weight Acquisition
Zones", issued to Alemany et al. on May 30, 1989.
[0062] The chassis 41 may further include an
acquisition/distribution core 84 of chemically stiffened fibers
positioned over the absorbent core 25, thereby forming a dual core
system. In a preferred embodiment, the fibers are hydrophilic
chemically stiffened cellulosic fibers. Herein, "chemically
stiffened fibers" means any fibers which have been stiffened by
chemical means to increase stiffness of the fibers under both dry
and aqueous conditions. Such means include the addition of chemical
stiffening agents which, for example, coat and/or impregnate the
fibers. Such means also include the stiffening of the fibers by
altering the chemical structure of the fibers themselves, e.g., by
cross-linking polymer chains.
[0063] The fibers utilized in the acquisition/distribution core 84
can also be stiffened by means of chemical reaction. For example,
crosslinking agents can be applied to the fibers which, subsequent
to application, are caused to chemically form intrafiber crosslink
bonds. These crosslink bonds can increase stiffness of the fibers.
Whereas the utilization of intrafiber crosslink bonds to chemically
stiffen the fibers is preferred, it is not meant to exclude other
types of reactions for chemical stiffening of the fibers.
[0064] In the more preferred stiffened fibers, chemical processing
includes intrafiber crosslinking with crosslinking agents while
such fibers are in a relatively dehydrated, defibrated (i.e.
individualized), twisted, curled condition. Suitable chemical
stiffening agents include monomeric crosslinking agents including,
but not limited to, C.sub.2-C.sub.8 dialdehydes and C.sub.2-C.sub.8
monoaldehydes having an acid functionality can be employed to form
the cross linking solution. These compounds are capable of reacting
with at least two hydroxyl groups in a single cellulose chain or on
proximately located cellulose chains in a single fiber. Such
crosslinking agents contemplated for use in preparing the stiffened
cellulose fibers include, but are not limited to, glutaraldehyde,
glyoxal, formaldehyde, and glyoxylic acid. Other suitable
stiffening agents are polycarboxylates, such as citric acid. The
polycarboxylic stiffening agents and a process for making stiffened
fibers from them are described in U.S. Pat. No. 5,190,563, entitled
"Process for Preparing Individualized, Polycarboxylic Acid
crosslinked Fibers" issued to Herron, on Mar. 2, 1993. The effect
of crosslinking under these conditions is to form fibers which are
stiffened and which tend to retain their twisted, curled
configuration during use in the absorbent articles herein. Such
fibers, and processes for making them are cited in the above
incorporated patents.
[0065] Preferred dual core systems are disclosed in U.S. Pat. No.
5,234,423, entitled "Absorbent Article With Elastic Waist Feature
and Enhanced Absorbency" issued to Alemany et al., on Aug. 10,
1993; and in U.S. Pat. No. 5,147,345, entitled "High Efficiency
Absorbent Articles For Incontinence Management" issued to Young,
LaVon and Taylor on Sep. 15, 1992. In a preferred embodiment, the
acquisition/distribution core 84 includes chemically treated
stiffened cellulosic fiber material, available from Weyerhaeuser
Co. (U.S.A.) under the trade designation of "CMC". Preferably, the
acquisition/distribution core 84 has a basis weight of from about
40 g/m.sup.2 to about 400 g/m.sup.2, more preferably from about 75
g/m.sup.2 to about 300 g/m.sup.2.
[0066] More preferably, the chassis 22 further includes an
acquisition/distribution layer 82 between the topsheet 24 and the
acquisition/distribution core 84 as shown in FIG. 4. The
acquisition/distribution layer 82 is provided to help reduce the
tendency for surface wetness of the topsheet 24. The
acquisition/distribution layer 82 preferably includes carded, resin
bonded hiloft nonwoven materials such as, for example, available as
Code No. FT-6860 from Polymer Group, Inc., North America
(Landisiville, N.J., U.S.A.), which is made of polyethylene
telephthalate fibers of 6 dtex, and has a basis weight of about 43
g/m.sup.2. A preferable example for the acquisition/distribution
layer 82 and the acquisition/distribution core 84 is disclosed in
EP 0797968A1 (Kurt et al.) published on Oct. 1, 1997.
[0067] The topsheet 24 is preferably compliant, soft feeling, and
non-irritating to the wearer's skin. Further, the topsheet 24 is
liquid pervious permitting liquids (e.g., urine) to readily
penetrate through its thickness. A suitable topsheet 24 may be
manufactured from a wide range of materials such as woven and
nonwoven materials; polymeric materials such as apertured formed
thermoplastic films, apertured plastic films, and hydroformed
thermoplastic films; porous foams; reticulated foams; reticulated
thermoplastic films; and thermoplastic scrims. Suitable woven and
nonwoven materials can be included of natural fibers (e.g., wood or
cotton fibers), synthetic fibers (e.g., polymeric fibers such as
polyester, polypropylene, or polyethylene fibers) or from a
combination of natural and synthetic fibers. The topsheet 24 is
preferably made of a hydrophobic material to isolate the wearer's
skin from liquids which have passed through the topsheet 24 and are
contained in the absorbent core 25 (i.e., to prevent rewet). If the
topsheet 24 is made of a hydrophobic material, at least the upper
surface of the topsheet 24 is treated to be hydrophilic so that
liquids will transfer through the topsheet more rapidly. This
diminishes the likelihood that body exudates will flow off the
topsheet 24 rather than being drawn through the topsheet 24 and
being absorbed by the absorbent core 25. The topsheet 24 can be
rendered hydrophilic by treating it with a surfactant. Suitable
methods for treating the topsheet 24 with a surfactant include
spraying the topsheet 24 material with the surfactant and immersing
the material into the surfactant. A more detailed discussion of
such a treatment and hydrophilicity is contained in U.S. Pat. No.
4,988,344 entitled "Absorbent Articles with Multiple Layer
Absorbent Layers" issued to Reising, et al. on Jan. 29, 1991 and
U.S. Pat. No. 4,988,345 entitled "Absorbent Articles with Rapid
Acquiring Absorbent Cores" issued to Reising on Jan. 29, 1991.
[0068] In a preferred embodiment, the topsheet 24 is a nonwoven web
that can provide reduced tendency for surface wetness; and
consequently facilitate maintaining urine absorbed by the core 25
away from the user's skin, after wetting. One of the preferred
topsheet materials is a thermobonded carded web which is available
as Code No. P-8 from Fiberweb North America, Inc. (Simpsonville,
S.C., U.S.A.). Another preferred topsheet material is available as
Code No. S-2355 from Havix Co., Japan. This material is a bi-layer
composite material, and made of two kinds of synthetic surfactant
treated bicomponent fibers by using carding and air-through
technologies. Yet another preferred topsheet material is a
thermobonded carded web which is available as Code No. Profleece
Style 040018007 from Amoco Fabrics, Inc. (Gronau, Germany).
[0069] In a preferred embodiment, the topsheet 24 is compatible
with other materials (e.g., component materials in the backsheet
22) used in the pull-on garment 20 or 120, in terms of its
design/process, for forming ventilation holes along the waist edge
152 and/or at other portions of the pull-on garment 20 or 120.
[0070] Another preferred topsheet 24 includes an apertured formed
film. Apertured formed films are preferred for the topsheet 24
because they are pervious to body exudates and yet non-absorbent
and have a reduced tendency to allow liquids to pass back through
and rewet the wearer's skin. Thus, the surface of the formed film
which is in contact with the body remains dry, thereby reducing
body soiling and creating a more comfortable feel for the wearer.
Suitable formed films are described in U.S. Pat. No. 3,929,135,
entitled "Absorptive Structures Having Tapered Capillaries", issued
to Thompson on Dec. 30, 1975; U.S. Pat. No. 4,324,246 entitled
"Disposable Absorbent Article Having A Stain Resistant Topsheet",
issued to Mullane, et al. on Apr. 13, 1982; U.S. Pat. No. 4,342,314
entitled "Resilient Plastic Web Exhibiting Fiber-Like Properties",
issued to Radel. et al. on Aug. 3, 1982; U.S. Pat. No. 4,463,045
entitled "Macroscopically Expanded Three-Dimensional Plastic Web
Exhibiting Non-Glossy Visible Surface and Cloth-Like Tactile
Impression", issued to Ahr et al. on Jul. 31, 1984; and U.S. Pat.
No. 5,006,394 "Multilayer Polymeric Film" issued to Baird on Apr.
9, 1991.
[0071] In a preferred embodiment, the backsheet 22 includes the
liquid impervious film 68 as shown in, for example, FIG. 4.
Preferably, the liquid impervious film 68 longitudinally extends in
the front, back and crotch regions 26, 28 and 30. More preferably,
the liquid impervious film 68 does not laterally extend into the at
least one of the ear panels 46 or 48. The liquid impervious film 68
has a body-facing surface 79 and an outer-facing surface 77. The
liquid impervious film 68 is impervious to liquids (e.g., urine)
and is preferably manufactured from a thin plastic film. However,
more preferably the plastic film permits vapors to escape from the
garment 20. In a preferred embodiment, a microporous polyethylene
film is used for the liquid impervious film 68. A suitable
microporous polyethylene film is manufactured by Mitsui Toatsu
Chemicals, Inc., Nagoya, Japan and marketed in the trade as PG-P.
In a preferred embodiment, a disposable tape (not shown in Figs.)
is additionally joined to the outer surface of the backsheet 22 to
provide a convenient disposal after soiling.
[0072] A suitable material for the liquid impervious film 68 is a
thermoplastic film having a thickness of from about 0.012 mm (0.5
mil) to about 0.051 mm (2.0 mils), preferably including
polyethylene or polypropylene. Preferably, the liquid impervious
film has a basis weight of from about 5 g/m.sup.2 to about 35
g/m.sup.2. However, it should be noted that other flexible liquid
impervious materials may be used. Herein, "flexible" refers to
materials which are compliant and which will readily conform to the
general shape and contours of the wearer's body.
[0073] Preferably, the backsheet 22 further includes the nonwoven
outer cover 74 which is joined with the outer-facing surface of the
liquid impervious film 68 to form a laminate (i.e., the backsheet
22). The nonwoven outer cover 74 is positioned at the outermost
portion of the garment 20 and covers at least a portion of the
outermost portion of the garment 20. In a preferred embodiment, the
nonwoven outer cover 74 covers almost all of the area of the
outermost portion of the garment 20. The nonwoven outer cover 74
may be joined to the liquid impervious film 68 by any suitable
attachment means known in the art. For example, the nonwoven outer
cover 74 may be secured to the liquid impervious film 68 by a
uniform continuous layer of adhesive, a patterned layer of
adhesive, or an array of separate lines, spirals, or spots of
adhesive. Suitable adhesives include a hotmelt adhesive obtainable
from Nitta Findley Co., Ltd., Osaka, Japan as H-2128, and a hotmelt
adhesive obtainable from H.B. Fuller Japan Co., Ltd., Osaka, Japan
as JM-6064.
[0074] In a preferred embodiment, the nonwoven outer cover 74 is a
carded nonwoven web, for example, obtainable from Havix Co., LTD.,
Gifu, Japan as E-2341. The nonwoven outer cover 74 is made of
bi-component fibers of a polyethylene (PE) and a polypropylene
(PP). The ratio of PE/PP is about 50/50. The PE/PP bi-component
fiber has the dimension of 2 d.times.51 mm. Another preferred
carded nonwoven web is obtainable from Chisso Corp., Moriyama,
Japan. The nonwoven outer cover 74 is also made of bi-component
fibers of a polyethylene (PE) and a polypropylene (PP). The ratio
of PE/PP is about 50/50.
[0075] In another preferred embodiment, the nonwoven web is a
spunbonded nonwoven web, for example, obtainable from Mitsui
Petrochemical Industries, Ltd., Tokyo, Japan. The nonwoven web is
made of bi-component fibers of a polyethylene (PE) and a
polypropylene (PP). The ratio of PE/PP is about 80/20. The PE/PP
bi-component fiber has the thickness is approximately 2.3 d.
[0076] In a preferred embodiment, the backsheet 22 is compatible
with other materials (e.g., component materials in the topsheet 24)
used in the pull-on garment 20 or 120, in terms of its
design/process, for forming ventilation holes along the waist edge
152 and/or for forming seams 32 in the pull-on garment 20 or
120.
[0077] The backsheet 22 is preferably positioned adjacent the
outer-facing surface of the absorbent core 25 and is preferably
joined thereto by any suitable attachment means known in the art.
For example, the backsheet 22 may be secured to the absorbent core
25 by a uniform continuous layer of adhesive, a patterned layer of
adhesive, or an array of separate lines, spirals, or spots of
adhesive. Adhesives which have been found to be satisfactory are
manufactured by H. B. Fuller Company of St. Paul, Minn., U.S.A.,
and marketed as HL-1358J. An example of a suitable attachment means
including an open pattern network of filaments of adhesive is
disclosed in U.S. Pat. No. 4,573,986 entitled "Disposable
Waste-Containment Garment", which issued to Minetola et al. on Mar.
4, 1986. Another suitable attachment means including several lines
of adhesive filaments swirled into a spiral pattern is illustrated
by the apparatus and methods shown in U.S. Pat. No. 3,911,173
issued to Sprague, Jr. on Oct. 7, 1975; U.S. Pat. No. 4,785,996
issued to Ziecker, et al. on Nov. 22, 1978; and U.S. Pat. No.
4,842,666 issued to Werenicz on Jun. 27, 1989. Alternatively, the
attachment means may include heat bonds, pressure bonds, ultrasonic
bonds, dynamic mechanical bonds, or any other suitable attachment
means or combinations of these attachment means as are known in the
art.
[0078] In an alternative embodiment, the absorbent core 25 is not
joined to the backsheet 22, and/or the topsheet 24 in order to
provide greater extensibility in the front region 26 and the back
region 28.
[0079] The pull-on garment 20 preferably further includes
elasticized leg cuffs 52 for providing improved containment of
liquids and other body exudates. The elasticized leg cuffs 52 may
include several different embodiments for reducing the leakage of
body exudates in the leg regions. (The leg cuffs can be and are
sometimes also referred to as leg bands, side flaps, barrier cuffs,
elastic cuffs or gasketing cuffs.) U.S. Pat. No. 3,860,003 entitled
"Contractable Side Portions for Disposable Diaper" issued to Buell
on Jan. 14, 1975, describes a disposable diaper which provides a
contractible leg opening having a side flap and one or more elastic
members to provide an elasticized leg cuff. U.S. Pat. No. 4,909,803
entitled "Disposable Absorbent Article Having Elasticized Flaps"
issued to Aziz et al. on Mar. 20, 1990, describes a disposable
diaper having "stand-up" elasticized flaps (barrier cuffs) to
improve the containment of the leg regions. U.S. Pat. No. 4,695,278
entitled "Absorbent Article Having Dual Cuffs" issued to Lawson on
Sep. 22, 1987; and U.S. Pat. No. 4,795,454 entitled "Absorbent
Article Having Leakage-Resistant Dual Cuffs" issued to Dragoo on
Jan. 3, 1989, describe disposable diapers having dual cuffs
including a gasketing cuff and a barrier cuff. U.S. Pat. 4,704,115
entitled "Disposable Waist Containment Garment" issued to Buell on
Nov. 3, 1987, discloses a disposable diaper or incontinence garment
having side-edge-leakage-guard gutters configured to contain free
liquids within the garment.
[0080] While each elasticized leg cuff 52 may be configured so as
to be similar to any of the leg bands, side flaps, barrier cuffs,
or elastic cuffs described above, it is preferred that the
elasticized leg cuff 52 includes an elastic gasketing cuff 62 with
one or more elastic strands 64 as shown in FIG. 3, which is
described in the above-referred U.S. Pat. Nos. 4,695,278 and
4,795,454. It is also preferred that each elasticized leg cuff 52
further includes inner barrier cuffs 54 each including a barrier
flap 56 and a spacing means 58 which are described in the
above-referenced U.S. Pat. No. 4,909,803.
[0081] The pull-on garment 20 preferably further includes an
elasticized waistband 50 that provides improved fit and
containment. The elasticized waistband 50 is that portion or zone
of the pull-on garment 20 which is intended to elastically expand
and contract to dynamically fit the wearer's waist. The elasticized
waistband 50 preferably extends longitudinally outwardly from the
waist edge of the pull-on garment 20 toward the waist edge of the
absorbent core 25. Preferably, the pull-on garment 20 has two
elasticized waistbands 50, one positioned in the back region 28 and
one positioned in the front region 26, although other pull-on
diaper embodiments can be constructed with a single elasticized
waistband. The elasticized waistband 50 may be constructed in a
number of different configurations including those described in
U.S. Pat. No. 4,515,595 entitled "Disposable Diapers with
Elastically Contractible Waistbands" issued to Kievit et al. on May
7, 1985 and the above referenced U.S. Pat. No. 5,151,092 issued to
Buell.
[0082] The waistbands 50 may include materials that have been
"prestrained" or "mechanically prestrained" (i.e., subjected to
some degree of localized pattern mechanical stretching to
permanently elongate the material). The materials may be
prestrained using deep embossing techniques as are known in the
art. Alternatively, the materials may be prestrained by directing
the material through an incremental mechanical stretching system as
described in U.S. Pat. No. 5,330,458 entitled "Absorbent Article
With Elastic Feature Having A Portion Mechanically Prestrained"
issued to Buell et al., on Jul. 19, 1994. The materials are then
allowed to return to their substantially untensioned condition,
thus forming a zero strain stretch material that is extensible, at
least up to the point of initial stretching. Examples of zero
strain materials are disclosed in U.S. Pat. No. 2,075,189 issued to
Galligan on Mar. 30, 1937; U.S. Pat. No. 3,025,199 issued to
Harwood on Mar. 13, 1962; U.S. Pat. Nos. 4,107,364 and 4,209,563
issued to Sisson on Aug. 15, 1978 and Jun. 24, 1980, respectively;
U.S. Pat. No. 4,834,741 issued to Sabee on May 30, 1989; and U.S.
Pat. No. 5,151,092 issued to Buell et al., on Sep. 29, 1992.
[0083] At least one of the ear panels 45, 46 and 48 includes the
elastic member 70 as shown in FIG. 4. The elastic member 70 of the
front ear panels 46 includes the elastomeric material 124 (not
shown in FIG. 4) which preferably extends laterally outward from
the chassis 41 to provide good fitness by generating the optimal
retention (or sustained) force at the waist and side areas of the
wearer. Preferably, the elastomeric material 124 is extensible in
at least one direction, preferably in the lateral direction to
generate a retention (or sustained) force that is optimal to
prevent the pull-on garment 20 from drooping, sagging, or sliding
down from its position on the torso without causing the red marking
on the skin of the wearer. In a preferred embodiment, each of the
ear panels 45, 46 and 48 includes the elastomeric material 124.
[0084] The elastic member 70 is operatively joined to at least one
of the nonwoven webs 72 and 74 in the ear panels 45, 46 and 48 to
allow the elastic member 70 to be elastically extensible in at
least the lateral direction. In a preferred embodiment, the elastic
member 70 is operatively joined to the nonwoven webs 72 and 74 by
securing them to at least one, preferably both of the nonwoven webs
72 and 74 while in a substantially untensioned (zero strain)
condition.
[0085] The elastic member 70 can be operatively joined to the
nonwoven webs 72 and 74, by using either an intermittent bonding
configuration or a substantially continuous bonding configuration.
Herein, "intermittently" bonded laminate web means a laminate web
wherein the plies are initially bonded to one another at discrete
spaced apart points or a laminate web wherein the plies are
substantially unbonded to one another at discrete spaced apart
areas. Conversely, a "substantially continuously" bonded laminate
web means a laminate web wherein the plies are initially bonded
substantially continuously to one another throughout the areas of
interface. It is preferred that the stretch laminate be bonded over
all or a significant portion of the stretch laminate so that the
inelastic webs (i.e., the nonwoven webs 72 and 74) elongate or draw
without causing rupture, and the layers of the stretch laminates
are preferably bonded in a configuration that maintains all of the
layers of the stretch laminate in relatively close adherence to one
another after the incremental mechanical stretching operation.
Consequently, the elastic panel members and the other plies of the
stretch laminate are preferably substantially continuously bonded
together using an adhesive. In a particularly preferred embodiment,
the adhesive selected is applied with a control coat spray pattern
at a basis weight of about 7.0 grams/square m. The adhesive pattern
width is about 6.0 cm. The adhesive is preferably an adhesive such
as is available from Nitta Findley Co., Ltd., Osaka, Japan, under
the designation H2085F. Alternatively, the elastic panel member and
any other components of the stretch laminates may be intermittently
or continuously bonded to one another using heat bonding, pressure
bonding, ultrasonic bonding, dynamic mechanical bonding, or any
other method as is known in the art.
[0086] After the elastic member 70 is operatively joined to at
least one of the nonwoven webs 72 and 74, at least a portion of the
resultant composite stretch laminate is then subjected to
mechanical stretching sufficient to permanently elongate the
non-elastic components which are, for example, the nonwoven webs 72
and 74. The composite stretch laminate is then allowed to return to
its substantially untensioned condition. At least one pair of,
preferably both of the ear panels 45, 46 and 48 is thus formed into
"zero strain" stretch laminates. (Alternatively, the elastic member
70 could be operatively joined in a tensioned condition and then
subjected to mechanical stretching; although this is not as
preferred as a "zero strain" stretch laminate.) Herein, "zero
strain" stretch laminate refers to a laminate included of at least
two plies of material which are secured to one another along at
least a portion of their coextensive surfaces while in a
substantially untensioned ("zero strain") condition; one of the
plies including a material which is stretchable and elastomeric
(i.e., will return substantially to its untensioned dimensions
after an applied tensile force has been released) and a second ply
which is elongatable (but not necessarily elastomeric) so that upon
stretching the second ply will be, at least to a degree,
permanently elongated so that upon release of the applied tensile
forces, it will not fully return to its original undeformed
configuration. The resulting stretch laminate is thereby rendered
elastically extensible, at least up to the point of initial
stretching, in the direction of initial stretching. Particularly
preferred methods and apparatus used for making stretch laminates
utilize meshing corrugated rolls to mechanically stretch the
components. Particularly preferred apparatus and methods are
disclosed in U.S. Pat. No. 5,167,897 issued to Weber et al. on Dec.
1, 1992; U.S. Pat. No. 5,156,793 issued to Buell et al. on Oct. 20,
1990; and U.S. Pat. No. 5,143,679 issued to Weber et al. on Sep. 1,
1992.
[0087] The elastic member 70 is preferably joined to, more
preferably directly secured to the respective edges 78 of the
liquid impervious film (i.e., the liquid impervious film 68)
through an adhesive 76 as shown in FIG. 4. In a preferred
embodiment, while liquid impervious film 68 longitudinally extends
in the front, back and crotch regions 26, 28 and 30, it does not
laterally extend into at least one of, preferably each of the
extensible ear panels 45, 46 and 48. In a more preferred
embodiment, the elastic member 70 is joined to the respective edges
78 of the liquid impervious film 68 at the outer-facing surface 77
as shown in FIG. 4. In an alternative embodiment, the elastic
member 70 may be joined to the respective edges 78 of the liquid
impervious film 68 at the body-facing surface 79 (not shown in
Figs.). Preferably, the adhesive 76 is applied in a spiral glue
pattern. In a preferred embodiment, the adhesive 76 is a flexible
adhesive with an amorphous and crystallizing component. Such a
preferred adhesive is made by Nitta Findley Co., Ltd., Osaka,
Japan, under the designation H2085F. Alternatively, the elastic
member 70 may be joined to the respective edges 78 of the liquid
impervious film 68 by any other bonding means known in the art
which include heat bonds, pressure bonds, ultrasonic bonds, dynamic
mechanical bonds, or combinations of these attachment means.
[0088] Referring to FIG. 6, the elastic member 70 includes the
elastomeric material 124 having a first surface 150 and a second
surface 152 opposing the first surface 150, and a first coverstock
layer 122 which is joined to the first surface 150 of the
elastomeric material 124. In a preferred embodiment, the first
coverstock layer 122 is joined to the first surface 150 of the
elastomeric material 124 by an adhesive 160 as shown, for example,
in FIG. 7. More preferably, the elastic member 70 further includes
a second coverstock layer 126 which is joined to the second surface
152 of the elastomeric material 124 by an adhesive 164.
[0089] Preferably, the elastic member 70 is joined to the
respective edges 78 of the liquid impervious film 68 at the
outer-facing surface 77 as shown in FIG. 4. In an alternative
embodiment, the elastic member 70 may be joined to the respective
edges 78 of the liquid impervious film 68 at the body-facing
surface 79 (not shown in Figs.).
[0090] The elastomeric material 124 may be formed in a wide variety
of sizes, forms and shapes. In a preferred embodiment, the
elastomeric material 124 is in the form of a continuous plane
layer. Preferred forms of continuous plane layer include a scrim, a
perforated (or apertures formed) film, an elastomeric woven or
nonwoven, and the like. The continuous plane layer may take any
shape which can be suitably provided in the ear panels. Preferred
shapes of continuous plane layer include a quadrilateral including
a rectangle and a square, a trapezoid, and the other polygons. In
an alternative embodiment, the elastomeric material 124 is in the
form of discrete strands (or strings) which are not connected each
other.
[0091] Elastomeric materials which have been found to be especially
suitable for the elastomeric material 124 are styrenic block
copolymer based scrim materials, perforated (or apertured) elastic
films, preferably with a thickness of from about 0.05 mm to about
1.0 mm (0.002 inch-0.039 inch). Other suitable elastomeric
materials for the elastomeric material 124 include "live" synthetic
or natural rubber, other synthetic or natural rubber foams,
elastomeric films (including heat shrinkable elastomeric films),
elastomeric woven or nonwoven webs, elastomeric composites, or the
like.
[0092] In a preferred embodiment, the elastomeric material 124 is a
porous, macroscopically-expanded, three-dimensional elastomeric web
172 as shown in FIG. 9. The web 172 has a continuous first surface
174 and a discontinuous second surface 176 remote from first
surface 174. The elastomeric web 172 preferably comprises a formed
film having at least two polymeric layers, with at least one of the
layers being an elastomer layer 178 and at least one of the other
layers being a substantially less elastomeric skin layer 182. The
elastomeric web exhibits a multiplicity of primary apertures 184 in
the first surface 174 of the web 172, the primary apertures 184
being defined in the plane of the first surface 174 by a continuous
network of interconnecting members 186. Each interconnecting member
186 exhibits an upwardly concave-shaped cross-section along its
length. The interconnecting members 186 terminate substantially
concurrently with one another to form a secondary aperture 188 in
the plane of the second surface of the web. The primary apertures
184 may have any shape. The detail of such a structure and the
method to manufacture is disclosed in U.S. patent application Ser.
No. 08/816,106, filed Mar. 14, 1997. A preferred porous elastomeric
material 124 is manufactured by the Tredegar Film Products under
the designation X-25007.
[0093] The extension properties of the side elastomeric material
124 such as the First Cycle Extension Force at 100% Extension
(FCEF100%), the First Cycle Extension Force at 200% Extension
(FCEF200%), the Second Cycle Recovery Force at 50% Extension
(SCRF50%) and sustained load at 50% after 10-12 hours are important
considerations in the performance of disposable garments. The side
elastomeric material 124 preferably has extension properties within
the defined ranges herein. The FCEF100% and the FCEF200% are
measures of the overall perceived "stretchiness" during
application/removal of disposable garments. These two properties
also affect the ability of the applicator to achieve a suitable
degree of application stretch. A side elastomeric material 124 with
a relatively high FCEF100% and FCEF200% can cause difficulty in
applying the disposable garment onto the wearer. On the other hand,
a side elastomeric material 124 with a relatively low FCEF100% and
FCEF200% may not achieve a suitable level of body
fitting/conformity. The SCRF50% also closely relates to the body
fitting/conformity of disposable garments for the wearer. A side
elastomeric material 124 with a relatively high SCRF50% tends to
cause red marking on the skin of the wearer and may be
uncomfortable for the wearer during usage. A side elastomeric
material 124 with a relatively low SCRF50% may not provide enough
elastic force to keep the diaper in place on the wearer or may not
provide good body fit. The sustained load at 50% after 10-12 hours
evaluates the force decay over time. This force decay should be
limited or substantial sagging will result.
[0094] The values of FCEF100%, FCEF200% and SCRF50% can be measured
by using a tensile tester. The tensile tester includes an upper jaw
and a lower jaw which is located below the upper jaw. The upper jaw
is movable and is connected to an extension force measuring means.
The lower jaw is fixed at a desk (or floor). A test specimen (i.e.,
the elastomeric material to be measured) which has about 2.54 cm
(1.0 inch) in width and about 12.75 cm (5 inches) in length is
prepared and clamped between the upper jaw and the lower jaw so
that the effective specimen length (L) (i.e., gauge length) is
about 5.08 cm (2.0 inches). The extension force is applied to the
test specimen through the upper jaw. When no extension force is
applied to the test specimen, the test specimen is in its original
length (i.e., 0% extension). A tensile tester suitable for use
herein is available from Instron Corporation (100 Royall Street,
Canton, Mass. 02021, U.S.A.) as Code No. Instron 5564.
[0095] FIG. 8 shows one preferred example of the extension and
recovery force curves for the two cycle hysteresis of the
elastomeric material 124. The curve E1 shows the extension force in
the first cycle, while the curve R1 shows the recovery force in the
first cycle. The curve E2 (shown in dashed lines) shows the
extension force in the second cycle, while the curve R2 shows the
recovery force in the second cycle. The extension and recovery
properties are measured as follows.
[0096] In the first cycle, the test specimen is subjected to an
initial extension force at a crosshead rate of 50.8 cm/min (20
in/min) at about 23.degree. C. and held for 30 seconds at 200%
extension. The test specimen is then allowed to relax at the same
rate to the original state (i.e., 0% extension). The test specimen
is allowed to remain unconstrained for one minute before being
subjected to a second extension force (for the second cycle) at the
same rate and conditions.
[0097] In preferred embodiments, the FCEF100% of the side
elastomeric material 124 is at least about 100 grams/inch. More
preferably, the FCEF100% is between about 120 to about 220
grams/inch, most preferably between about 150 grams/inch and 190
grams/inch. The FCEF200% is preferably between about 160 grams/inch
and about 450 grams/inch, more preferably between about 180
grams/inch and about 300 grams/inch, and yet more preferably
between about 200 grams/inch and about 240 grams/inch. The SCRF50%
of the side elastomeric material 124 is preferably between about 40
grams/inch and about 130 grams/inch, more preferably between about
65 grams/inch and about 105 grams/inch, and yet more preferably
between about 75 grams/inch and about 95 grams/inch. The sustained
load at 50% after 10-12 hours is preferably between about 40
grams/inch and about 130 grams/inch, more preferably between about
65 grams/inch and about 105 grams/inch, and yet more preferably
between about 75 grams/inch and about 95 grams/inch.
[0098] In the preferred embodiment shown in FIG. 6, the elastomeric
scrim 124 has a plurality of first strands 125 and a plurality of
second strands 127. The plurality of first strands 125 intersect
the plurality of second strands 127 at nodes 130 at a predetermined
angle a, forming a net-like open structure having a plurality of
apertures 132. Each aperture 132 is defined by at least two
adjacent first strands and at least two adjacent second strands, so
that the apertures 132 are substantially rectangular in shape.
Other configurations of the apertures 132, such as parallelograms,
squares, or circular arc segments, can also be provided.
Preferably, the first and second strands 125 and 127 are
substantially straight and substantially parallel to one another.
Preferably, the first strands 125 intersect the second strands 127
at nodes 130 such that the angle .alpha. is about 90 degrees. The
first and second strands 125 and 127 are preferably joined or
bonded at nodes 90.
[0099] A preferred elastomeric scrim 124 is manufactured by the
Conwed Plastics Company (Minneapolis, Minn., U.S.A.) under the
designation XO2514. This material has about 12 elastic strands per
inch in the structural direction B (i.e., the first strands 125)
and about 7 elastic strands per inch in the structural direction D
(i.e., the second strands 127).
[0100] In the embodiment shown in FIG. 6, the elastic member 70
includes first and second coverstock layers 122 and 126, and
elastomeric material 124 disposed in the first and second
coverstock layers 122 and 126. The first coverstock layer 122 has
an inner surface 142 and an outer surface 144. The inner surface
142 of the first coverstock layer 122 is the surface that is
positioned facing the elastomeric material 124. The second
coverstock layer 126 also has an inner surface 146 and an outer
surface 148. The inner surface 146 of the second coverstock layer
126 is the surface that is positioned facing the elastomeric
material 124. The elastomeric material 124 also has two planar
surfaces, first surface 150 and second surface 152, each of which
is substantially parallel with the planes of the first and second
coverstock layers 122 and 126. The first surface 150 is that planar
surface of the elastomeric material 124 that is most closely
adjacent with the inner surface 142 of first coverstock layer 122.
The second surface 152 is that planar surface of elastomeric
material 124 that is most closely adjacent to the inner surface 146
of the second coverstock layer 126.
[0101] Since the elastic member 70 will be subjected to mechanical
stretching before and during use, the first and second coverstock
layers 122 and 126 preferably have a relatively high elongation at
breaking, and are more preferably stretchable or elongatable, yet
more preferably drawable (but not necessarily elastomeric), without
undue (and preferably without any), tearing or ripping. Further,
the first and second coverstock layers 122 and 126 are preferably
compliant, soft feeling, and non-irritating to the wearer's skin
and give the article the feel and comfort of a cloth garment.
Suitable materials for the first and second coverstock layers 122
and 126 can be manufactured from a wide range of materials such as
plastic films, apertured plastic films, woven or nonwoven webs of
natural fibers (e.g., wood or cotton fibers), synthetic fibers
(e.g., polyolefins, polyamides, polyester, polyethylene, or
polypropylene fibers), or a combination of natural and/or synthetic
fibers, or coated woven or nonwoven webs.
[0102] Preferably, each of the first and second coverstock layers
122 and 126 is an identical consolidated nonwoven material. An
exemplary preferred nonwoven material is manufactured by the
Fiberweb North America, Inc. (Simpsonville, S.C., U.S.A.) under the
designation Sofspan 200. This material has a basis weight of 25
g/m.sup.2 before consolidation and a basis weight of about 63 g/m2
after consolidation. Herein, "basis weight" is the weight of one
square meter of planar web material. Alternatively, highly
strainable nonwoven materials may be used. Alternatively, the first
and second coverstock layers 122 and 126 need not be of identical
materials, as long as the desired performance requirements, such as
elastic performance, softness, flexibility, breathability and
durability, are met. Herein, "consolidated nonwoven material" means
a nonwoven material that has been gathered or necked under
mechanical tension in the structural direction D so that the
material can elongate in the structural direction D under low
force.
[0103] FIG. 7 shows a fragmentary enlarged side view looking into
the structural direction B of the laminate 120 (i.e., the elastic
member 70). It has been found that when the laminate 120 is bonded
or otherwise anchored such that side anchor zones A are created,
such a laminate 120 is both highly elastic and substantially free
from delamination and creep, while providing very good performance
characteristics in all performance categories with no trade-offs
between any performance characteristics required. The side
anchoring is preferably performed by side gluing with adhesive
beads to anchor the elastomeric material 124 between the coverstock
layers 122 and 126 as a part of the lamination process.
Alternatively, side anchoring may be performed by sewing, heat
sealing, ultrasound bonding, needle punching, alternative gluing
processes, or by any other means known to those skilled in the art.
Another alternative is to side anchor the layers of the laminate
structure after the lamination of the elastomeric and coverstock
components has been performed.
[0104] Preferably, the laminate 120 may particularly provide very
good soft feel for the wearer and for the consumer. This is
important because consumers value softness. In conventional
laminates, the attempts to eliminate creep have frequently required
an unacceptable decrease in softness, often accompanied by an
unacceptable decrease in an ability to activate. This is because
such previous attempts (which have fallen short of eliminating
creep) have focused on the application of additional melt blown
adhesive, often in an overall coating pattern, in the attempt to
strengthen the bonds. This has generally resulted in an undesirable
overall stiffening of the laminate. However, the laminates of the
preferred embodiments provide elimination of creep without the loss
of consumer-desired soft feel and without compromise of activation
ability.
[0105] Referring to FIG. 7, a first adhesive 170 is applied to the
inner surface 146 of the second coverstock layer 126 in positions
that correspond to each of the outer edges 180 of the laminate
structure 120. The first adhesive 170 may alternatively or
additionally be applied to the inner surface 142 of the first
coverstock layer 122. For ease of illustration, the description and
Figs. refer to application to the second coverstock layer 126
only.
[0106] This pattern creates side anchor zones A, which
substantially eliminate the delamination and creep associated with
previously known laminates and which allows the laminate 120 to
experience higher strains without creeping or delaminating. It has
also been found that confining the first adhesive 170 to the edge
areas 180 of the laminate structure 120 avoids impeding the
extensibility of the laminate 120 and also avoids tears in the
coverstock layers 122 and 126. Preferably, the first adhesive 170
is applied as a plurality of beads 168, as shown in FIG. 7.
Preferably, the first adhesive 170 is a flexible adhesive with an
amorphous and crystallizing component. Such a preferred adhesive is
made by Nitta Findley Co., Ltd., Osaka, Japan, under the
designation H9224.
[0107] More preferably, the laminate 120 includes a second adhesive
164. The second adhesive 164 is preferably applied to the second
surface 152 of the elastomeric material 124, but could
alternatively be applied to the first surface 150 of the
elastomeric material 124. The second adhesive 164 is preferably
applied in a spiral spray pattern 166, thereby forming bond points
167b that are more discrete than would be formed by a linear spray
application. Without being bound by theory, it is believed that
most of the second adhesive 164 is sprayed in the structural
direction D (FIG. 6). Thus, it has been found that spiral spraying
results in very good activation properties. Herein, "activation"
refers to the ability to stretch.
[0108] It has been found that spraying the layer of second adhesive
164 directly onto the second surface 152 of the elastomeric
material 124 is more preferable than applying the second adhesive
164 to the opposing (i.e., second) coverstock layer 126. This is
because the second adhesive 164 tends to penetrate through any
residual processing agents or oils that may remain on the surface
of the elastomeric material 124. Such residual materials, if left
to remain on the elastomeric material 124, may weaken the adhesive
bonds and thus the laminate structure 120 over time. For example,
if these residual materials are left intact, the bonds used to form
the laminate 120 may weaken during the time interval prior to
consumer purchase of the product.
[0109] Peel values for the laminate 120 in the spiral adhesive
areas are typically higher when the spirals 166 are applied
directly to the elastomeric material 124 than to the opposing
(i.e., second) coverstock layer 126. Herein, "peel value" refers to
the amount of force required to separate the two layers of
coverstock material, 122 and 126, from each other. Higher peel
values typically equate to less chance of delamination in use.
[0110] A third adhesive 160 may also preferably be applied to the
inner surface 142 of the first coverstock layer 122. Preferably,
the third adhesive 160 is an elastomeric adhesive. In a manner
similar to that described with reference to the second spiral
adhesive application 166, the first adhesive 160 is preferably
applied in a spiral spray pattern 162, thereby forming bond points
167a that are more discrete than would be formed by a linear spray
application. Without being bound by theory, it is believed that
most of the first adhesive 160 so sprayed aligns in the structural
direction D.
[0111] Preferably, second and third adhesives 160 and 164 are the
same elastomeric adhesive. A preferred adhesive for use in the
second and third adhesive spiral sprays 162 and 166 is made by
Nitta Findley Co., Ltd., Osaka, Japan, under the designation H2120.
Preferably, the add-on level for each of the second and third
spiral sprays 162 and 166 is about 4 to about 12 milligrams per
square inch, more preferably about 8 milligrams per square
inch.
[0112] The dimensions and values disclosed herein are not to be
understood as being strictly limited to the exact numerical values
recited. Instead, unless otherwise specified, each such dimension
is intended to mean both the recited value and a functionally
equivalent range surrounding that value. For example, a dimension
disclosed as "40 mm" is intended to mean "about 40 mm."
[0113] Every document cited herein, including any cross referenced
or related patent or application, is hereby incorporated herein by
reference in its entirety unless expressly excluded or otherwise
limited. The citation of any document is not an admission that it
is prior art with respect to any invention disclosed or claimed
herein or that it alone, or in any combination with any other
reference or references, teaches, suggests or discloses any such
invention. Further, to the extent that any meaning or definition of
a term in this document conflicts with any meaning or definition of
the same term in a document incorporated by reference, the meaning
or definition assigned to that term in this document shall
govern.
[0114] While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention. It is therefore intended to cover in the appended claims
all such changes and modifications that are within the scope of
this invention.
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