Abstract
A simple disposable absorbent article, which can be a pull-on garment,
includes a chassis and an absorbent assembly. A belt is fastenable
to the chassis, and both the belt and the chassis can be independently
extensible or substantially inextensible. The belt can be fastened
to the chassis at opposing ends, at least one of which being releasable
and refastenable to induce a tension in the belt and a contractive
force on the underlying chassis, thereby enhancing the fit of the
garment at the wearer's waist. The belt can further define a frangible
region that can be broken to define opposing outer ends, at least
one of which can be drawn and refastened to induce the contractive
force on the underlying chassis.
Claims
1. A disposable absorbent article comprising: a chassis defining a
front waist region, a back waist region, a crotch region disposed
between the waist regions, a waist opening, and a pair of leg openings;
an absorbent assembly attached to the chassis; and a belt member attached
to the chassis, the belt member extending across at least a portion
of the chassis, the belt member including a frangible joint that is
breakable to define a first and second free end, wherein the free
ends are fastenable to at least one of each other and the chassis
to impart a contractive force onto the chassis.
2. The disposable absorbent article as recited in claim 1, wherein
the belt member is disposed in both the front and back waist regions
of the garment.
3. The disposable absorbent article as recited in claim 1, wherein
the belt member surrounds only a portion of the chassis before the
frangible joint is broken.
4. The disposable absorbent article as recited in claim 3, wherein
the frangible joint divides the belt member into first and second
segments, each segment defining the first and second free ends,
respectively.
5. The disposable absorbent article as recited in claim 1, wherein
the belt further comprises an attachment zone disposed adjacent
at least one of the free ends.
6. The disposable absorbent article as recited in claim 1, wherein
at least one of the free ends is releasable and subsequently attachable
to at least one of the chassis and a remaining segment of the belt
member.
7. The disposable absorbent article as recited in claim 6, wherein
the free ends are tied in a knot.
8. The disposable absorbent article as recited in claim 1, wherein
the belt extends substantially along a longitudinal belt axis.
9. The disposable absorbent article as recited in claim 8, wherein
at least a portion of the frangible joint extends in a direction
parallel to the longitudinal belt axis.
10. The disposable absorbent article as recited in claim 9, wherein
the frangible joint extends from opposing closed side interfaces
on the chassis.
11. The disposable absorbent article as recited in claim 8, wherein
at least a portion of the frangible joint extends in a direction
perpendicular to the longitudinal belt axis.
12. The disposable absorbent article as recited in claim 8, wherein
at least a portion of the frangible joint extends in a direction
angled with respect to both 1) a direction perpendicular to the
longitudinal belt axis 2) a direction parallel to the longitudinal
belt axis.
13. The disposable absorbent article as recited in claim 1, wherein
the belt member overlaps at least a portion of the front waist region.
14. The disposable absorbent article as recited in claim 13, wherein
the belt member overlaps substantially all of the front waist region.
15. The disposable absorbent article as recited in claim 1, wherein
the belt member overlaps at least a portion of the back waist region.
16. The disposable absorbent article as recited in claim 1, wherein
the belt member overlaps substantially all of the front waist region.
17. The disposable absorbent article as recited in claim 1, wherein
the belt member overlaps a closed side interface of the chassis.
18. The disposable absorbent article as recited in claim 1, wherein
at least a portion of the belt member is extensible.
19. The disposable absorbent article as recited in claim 18, wherein
the belt member is pre-tensioned.
20. The disposable absorbent article as recited in claim 18, wherein
the belt member is non-pre-tensioned.
21. The disposable absorbent article as recited in claim 1, wherein
at least a portion of the belt member is non-extensible.
22. The disposable absorbent article as recited in claim 1, wherein
at least a portion of the chassis is extensible.
23. The disposable absorbent article as recited in claim 1, wherein
at least a portion of the chassis is non-extensible.
24. The disposable absorbent article as recited in claim 1, further
comprising a pull-on garment.
25. A method for securing a disposable absorbent article on a waist
region of a wearer, the garment including a chassis defining a front
waist region, a back waist region, and a crotch region disposed
between the waist regions, the front and waist regions being closed
to define a waist opening, the diaper further comprising a belt
member attached to the chassis, the belt member including a frangible
joint, wherein the method comprises the steps of: A) pulling the
absorbent article up to the waist region of the wearer such that
the waist region is surrounded by the waist opening; B) breaking
the frangible joint to define first and second free ends; C) after
step (B), attaching at least one of the free ends to one of the
chassis and a remaining portion of the belt member, thereby creating
a contractive belt force to the chassis.
26. The method as recited in claim 25, wherein step (C) further
comprising drawing the free ends together.
27. A disposable absorbent article comprising: a chassis defining
a front waist region, a back waist region, a crotch region disposed
between the waist regions, a waist opening, and a pair of leg openings;
an absorbent assembly attached to the chassis; and a belt member
attached to the chassis at a first location, the belt member extending
across at least portion of the chassis, the belt member defining
opposing outer ends attached to the chassis at corresponding attachment
zones, wherein at least one of the attachment zones is releasably
attached to the chassis, wherein the releasable attachment zone
can be released from the chassis and reattached to the chassis in
a second location different than the first location, such that the
belt applies a contractive belt force to the chassis.
28. The disposable absorbent article as recited in claim 27, further
comprising a pull-on pant.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to disposable absorbent articles
such as disposable diapers and other articles intended for use on
incontinent persons and, in particular, relates to an apparatus
that enhances the fit of such disposable absorbent articles on the
body of the wearer.
BACKGROUND OF THE INVENTION
[0002] Disposable absorbent articles are designed to absorb and
contain bodily waste in order to prevent soiling of the body and
clothing of the wearer, as well as bedding or other objects with
which the wearer comes into contact. Disposable pant-like garments,
especially those of the "pull-on" type, include a pair
of side edges, each defining corresponding closed side interfaces
that, in turn, define an encircled waist opening and a pair of encircled
leg openings. Accordingly, pull-on garments can be more easily applied
to a wearer, especially a standing wearer, than taped diapers which
require manual fastening to define the waist and leg openings and
secure the diaper on the wearer.
[0003] As the usage of disposable absorbent articles has expanded,
the incorporation of additional absorbent article features has correspondingly
increased to enhance the performance and appearance of the articles.
Unfortunately, the resulting increase in absorbent article complexity
has caused the costs of the materials and the manufacturing processes
to increase which, in turn, has caused the prices at which these
articles are sold to have risen to levels that many potential purchasers
around the world cannot afford to pay.
[0004] Accordingly, simple disposable absorbent articles can have
an extensible chassis that can extend as the articles are applied
to the wearer's waist region. Specifically, as such an article is
applied to the wearer, portions of the chassis can extend elastically
up to the point at which plastic deformation occurs. As a result,
a portion of the chassis at the wearer's waist region extended into
the region of plastic deformation may fit more loosely about the
wearer relative to other portions of the chassis that were not extended
to the point of plastic deformation during application of the pant
to the wearer.
[0005] Furthermore conventional disposable pull-on garments having
performance and appearance-enhancing features that lack the extensibility
to fit over the hips of the wearer may be designed such that they
are slightly oversized relative to the hips and waist of the wearer
such that they may be applied to the wearer. Such garments result
in a relatively loose fit about the wearer's waist region.
[0006] What is therefore needed is an inexpensive apparatus that
enhances the fit of an absorbent article about the waist region
of the wearer.
SUMMARY OF THE INVENTION
[0007] The present invention provides a belt designed for absorbent
articles that can be tightened and fastened to apply a contractive
force to the underlying chassis.
[0008] In accordance with one aspect of the invention, a disposable
pull-on garment includes a chassis, an absorbent assembly attached
to the chassis, and a belt member. The chassis defines a front waist
region, a back waist region, a crotch region disposed between the
waist regions, a waist opening, and a pair of leg openings. The
belt member is attached to the chassis in a waist region, and extends
across at least a portion of the chassis. The belt member comprises
a frangible joint that is breakable to define first and second free
ends. The free ends are fastenable to at least one of each other
and the chassis to impart a contractive force onto the chassis.
[0009] In accordance with another aspect of the invention, a method
is provided for securing a pull-on garment at the waist region of
a wearer. The garment includes a chassis defining a front waist
region, a back waist region, and a crotch region disposed between
the waist regions. The front and back waist regions are closed to
define a waist opening. The diaper further includes a belt member
attached to the chassis, the belt member comprising a frangible
joint. The method includes the steps of A) pulling the absorbent
article up to the waist region of the wearer such that the waist
region is surrounded by the waist opening; B) breaking the frangible
joint to define first and second free ends; C) after step (B), attaching
at least one of the free ends to one of the chassis and a remaining
portion of the belt member, thereby creating a contractive belt
force to the chassis.
[0010] In accordance with yet another aspect of the invention,
a disposable pull-on garment includes a chassis, an absorbent assembly
attached to the chassis, and a belt member. The chassis defines
a front waist region, a back waist region, a crotch region disposed
between the waist regions, a waist opening and a pair of leg openings.
The belt member is attached to the chassis at a first location,
and extends across at least a portion of the chassis. The belt member
defines opposing outer ends attached to the chassis at corresponding
attachment zones. At least one of the attachment zones is releasably
attached to the chassis, wherein the releasable attachment zone
can be released from the chassis and reattached to the chassis in
a second location, different from the first location, such that
belt applies a contractive belt force to the chassis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the accompanying drawing figures, like reference numerals
identify like elements, which may or may not be identical in the
several exemplary embodiments that are depicted. Some of the figures
may have been simplified by the omission of selected elements for
the purpose of more clearly showing other elements. Such omissions
of elements in some figures are not necessarily indicative of the
presence or absence of particular elements in any of the exemplary
embodiments, except as may be explicitly delineated in the corresponding
written description.
[0012] FIG. 1 is a perspective view of a disposable pull-on garment
constructed in accordance with one aspect of the present invention;
[0013] FIG. 2 is a front elevation view of an exemplary pull-on
garment having been pulled over the lower torso region of the wearer
illustrating portions of the garment that are not securely fit to
the wearer's body;
[0014] FIG. 3A is a perspective view of an absorbent article similar
to FIG. 1 but incorporating a belt aligned with the front waist
region in accordance with one aspect of the invention;
[0015] FIG. 3B is a perspective view of an absorbent article similar
to FIG. 3A but with the belt aligned with the back waist region
in accordance with another aspect of the invention;
[0016] FIG. 3C is a perspective view of an absorbent article similar
to FIGS. 3A-B but with the belt disposed substantially at the side
of the article;
[0017] FIG. 4 is a side elevation view of a portion of an absorbent
article illustrating a belt being tightened to enhance the fit of
the article about the wearer;
[0018] FIG. 5A is a front elevation view of a portion of a pull-on
garment including a belt having a frangible region;
[0019] FIG. 5B is a front elevation view of a portion of a pull-on
garment as illustrated in FIG. 5A after the frangible region has
been broken to define a pair of outer ends;
[0020] FIG. 5C is a front elevation view of a portion of a pull-on
garment as illustrated in FIG. 5B after the outer ends have been
fastened in accordance with one embodiment;
[0021] FIG. 5D is a front elevation view of a portion of a pull-on
garment as illustrated in FIG. 5B after the outer ends have been
fastened in accordance with another embodiment;
[0022] FIG. 5E is a front elevation view of a portion of a pull-on
garment as illustrated in FIG. 5B after the outer ends have been
fastened in accordance with still another embodiment;
[0023] FIG. 5F is a front elevation view of a portion of a pull-on
garment as illustrated in FIG. 5B after the outer ends have been
fastened in accordance with still another embodiment;
[0024] FIG. 6 is a perspective view of an absorbent article including
a circumferential belt that surrounds both the front and back waist
regions;
[0025] FIG. 7A is a front elevation view of a portion of an absorbent
article as illustrated in FIG. 5A including a belt having a frangible
region constructed in accordance with an alternative embodiment;
[0026] FIG. 7B is a perspective view of the absorbent article illustrated
in FIG. 7A with the frangible region configured in accordance with
one aspect of the invention;
[0027] FIG. 7C is a perspective view of the absorbent article similar
to FIG. 7B but with the frangible region configured in accordance
with another aspect of the invention;
[0028] FIG. 7D is a front elevation view of a portion of an absorbent
article as illustrated in FIG. 7A with the frangible region constructed
in accordance with an alternative embodiment;
[0029] FIG. 8 is a plan view of a disposable absorbent article
prior to being configured as a pull-on garment, with the interior
portion of the garment that faces inwardly toward the wearer and
contacts the wearer shown facing the viewer, in which the garment
is shown in its flat, uncontracted state (i.e., without the contraction
induced by elastic members);
[0030] FIG. 9 is a plan view of the absorbent article illustrated
in FIG. 8 in its flat, uncontracted state, with the exterior portion
of the garment that faces outwardly away from the wearer shown facing
the viewer;
[0031] FIG. 10 is a section view of the garment illustrated in
FIG. 8 taken along line 10-10;
[0032] FIG. 11 is a section view of the garment illustrated in
FIG. 8 taken along line 11-11;
[0033] FIG. 12 is a section view of the garment illustrated in
FIG. 8 taken along line 12-12;
[0034] FIG. 13 is a section view of the garment illustrated in
FIG. 8 taken along line 13-13;
[0035] FIG. 14A is a schematic perspective view of the garment
illustrated in FIG. 8 configured as a pull-on garment showing the
side interfaces constructed in accordance with one embodiment of
the present invention;
[0036] FIG. 14B is a schematic perspective view of the garment
illustrated in FIG. 8 configured as a pull-on garment showing the
side interfaces constructed in accordance with an alternative embodiment;
[0037] FIG. 14C is a schematic perspective view of the garment
illustrated in FIG. 8 configured as a pull-on garment showing the
side interfaces constructed in accordance with an alternative embodiment;
[0038] FIG. 14D is a schematic perspective view of the garment
illustrated similar to FIG. 14D showing a belt being attached integrally
into one of the side interfaces;
[0039] FIG. 15 is a plan view of a pull-on garment constructed
in accordance with an alternative embodiment, with the interior
portion of the garment that faces inwardly toward the wearer and
contacts the wearer shown facing the viewer, shown in its flat,
uncontracted state (i.e., without the contraction induced by elastic
members) before side flaps are formed by folding portions of the
chassis laterally inward;
[0040] FIG. 16 is a plan view of the garment illustrated in FIG.
15 in its flat, uncontracted state, with the exterior portion of
the garment that faces outwardly away from the wearer shown facing
the viewer;
[0041] FIG. 17 is a section view of the garment illustrated in
FIG. 15 taken along line 17-17;
[0042] FIG. 18 is a section view of the garment illustrated in
FIG. 15 taken along line 18-18;
[0043] FIG. 19 is a section view of the garment illustrated in
FIG. 15 taken along line 19-19;
[0044] FIG. 20 is a section view of the garment illustrated in
FIG. 15 taken along line 20-20;
[0045] FIG. 21 is a perspective view of a pull-on garment, with
the interior portion of the garment that faces inwardly toward the
wearer and contacts the wearer shown facing upward, in which the
garment is shown in its contracted state prior to being configured
into a pull-on garment (i.e., with the contraction induced by elastic
members);
[0046] FIG. 22 is a plan view of an exemplary fragment of a formed
web material;
[0047] FIG. 23 is a plan view of an absorbent assembly, with the
interior portion of the absorbent assembly that faces inwardly toward
the wearer and contacts the wearer shown facing the viewer, in which
the absorbent assembly is shown separate from a chassis to which
it is attached in an exemplary garment;
[0048] FIG. 24 is a section view of the absorbent assembly illustrated
in FIG. 23 taken along line 24-24;
[0049] FIG. 25 is a section view of the absorbent assembly illustrated
in FIG. 23 taken along line 25-25;
[0050] FIG. 26 is a plan view of an exemplary garment having portions
removed to illustrate the garment in a stretched configuration.
[0051] FIG. 27 is a plan view of an exemplary absorbent article
having a fastening device, wherein the absorbent article is positioned
in its flat out uncontracted state (i.e., without elastic induced
contraction), with the body-facing surface facing the viewer, having
portions cut-away; and
[0052] FIG. 28 is a plan view of an exemplary fastening device
in its fastened configuration.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0053] In this description, the following terms have the following
meanings:
[0054] The term "absorbent article" refers to a device
that absorbs and contains liquid and, more specifically, refers
to a device that is placed against or in proximity to the body of
the wearer to absorb and contain the various exudates discharged
from the body. Exemplary absorbent articles include diapers, training
pants, pull-on pant-type diapers (i.e., a diaper having a pre-formed
waist opening and leg openings such as illustrated in U.S. Pat.
No. 6,120,487), refastenable diapers or pant-type diapers, incontinence
briefs and undergarments, diaper holders and liners, feminine hygiene
garments and the like.
[0055] The term "diaper" refers to an absorbent article
that is generally worn by infants and incontinent persons about
the lower torso so as to encircle the waist and the legs of the
wearer and that is specifically adapted to receive and contain urinary
and fecal waste. The term "closed side interface" refers
to a given side edge (or region adjacent the side edge), wherein
a portion of the side edge (or region adjacent the side edge) in
the front waist region is joined to a portion of the same side edge
(or region adjacent the side edge) in the rear waist region to define
closed, encircled leg openings and a closed waist opening. The side
interface can be closed with a refastenable or permanent closure
member.
[0056] The term "pant" (also referred to as "training
pant", "closed diaper", and "pull-on garment")
refers to disposable garments having a continuous perimeter waist
opening and continuous perimeter leg openings designed for infant
or adult wearers. A pant can be configured with a continuous or
closed waist opening and at least one continuous, closed, leg opening
prior to the article being applied the wearer for use. A pant can
be preformed by any suitable technique including, but not limited
to, joining together portions of the article using any refastenable
and/or permanent closure member (e.g., seams, heat bonds, pressure
welds, adhesives, cohesive bonds, mechanical fasteners, etc.). A
pant can be preformed anywhere along the circumference of the article
in the waist region (e.g., side fastened, front waist fastened,
rear waist fastened). Examples of suitable pants are disclosed in
U.S. Pat. No. 5,246,433; U.S. Pat. No. 5,569,234; U.S. Pat. No.
6,120,487; U.S. Pat. No. 6,120,489; U.S. Pat. No. 4,940,464; U.S.
Pat. No. 5,092,861; U.S. Pat. No. 5,897,545; U.S. Pat. No. 5,957,908;
and U.S. Patent Publication No. 2003/0233082 A1.
[0057] The term "closure member" refers to an element
that maintains the article waist and leg openings in a closed, continuous,
configuration until the closure member is released. Suitable closure
members include a seam, an adhesive, a cohesive, a heat bond, a
pressure bond or weld, a tab-and-slot configuration, a hook-and-loop
configuration, and the like.
[0058] The term "refastenable closure member" refers
to a closure member that can be opened and subsequently re-closed,
reliably, without destroying the closure member or surrounding diaper
components. Examples of refastenable closure members include tabs-and-slots,
hooks-and-loops, peelable adhesives, cohesives, and the like
[0059] The term "permanent closure member" refers to
a closure member that cannot be opened without causing the closure
member to fail (i.e., the closure member cannot again be reliably
closed). At times, when attempting to open a permanent closure member,
surrounding absorbent article component(s) may be damaged or torn.
Examples of permanent closure members include adhesives, heat bonds,
pressure welds, cohesives, and the like, and further include seams.
[0060] The term "seam" refers to an elongated line of
junction that attaches two regions of a diaper chassis. Seams can
be created via thermal bonds, pressure bonds, ultrasonic bonds,
permanent adhesive bonds, permanent cohesive bonds, welds, and stitching.
A seam can be configured as a permanent closure member.
[0061] The term "cohesive" refers to the property of
a material that sticks to itself but does not to any significant
degree stick to other materials.
[0062] The term "disposable" refers to the nature of
absorbent articles that generally are not intended to be laundered
or otherwise restored or reused as an absorbent article, 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.
[0063] The term "extensible" refers to any material which,
upon application of a biasing force less than 500 grams/inch, is
elongatable at least about 20 percent without experiencing catastrophic
failure.
[0064] The term "longitudinal" refers to a direction
running generally parallel to the maximum linear dimension of an
element. Directions within .+-.45.degree. of the longitudinal direction
are considered to be "longitudinal".
[0065] The term "lateral" refers to a direction running
generally at a right angle to the longitudinal direction. Directions
within .+-.45.degree. of the lateral direction are considered to
be "lateral".
[0066] The term "disposed" refers to an element or region
being attached and/or positioned in a particular place or position
in a unitary structure with other elements.
[0067] The term "attached" refers to elements being connected
or united by fastening, adhering, bonding, etc. by any method suitable
for the elements being attached together and their constituent materials.
Many suitable methods for attaching elements together are well-known,
including adhesive bonding, pressure bonding, thermal bonding, mechanical
fastening, etc. Such attachment methods can be used to attach elements
together over a particular area either continuously or intermittently.
[0068] The terms "water-permeable" and "water-impermeable"
refer to the penetrability of materials in the context of the intended
usage of disposable absorbent articles. Specifically, the term "water-permeable"
refers to a layer or a layered structure having pores, openings,
and/or interconnected void spaces that permit liquid water to pass
through its thickness in the absence of a forcing pressure. Conversely,
the term "water-impermeable" refers to a layer or a layered
structure through the thickness of which liquid water cannot pass
in the absence of a forcing pressure. A layer or a layered structure
that is water-impermeable according to this definition can be permeable
to water vapor, i.e., can be "vapor-permeable". As is
well known in the art, a common method for measuring the permeability
to water of the materials typically used in absorbent articles is
a hydrostatic pressure test, also called a hydrostatic head test
or simply a "hydrohead" test. Suitable well known compendial
methods for hydrohead testing are approved by INDA (formerly the
International Nonwovens and Disposables Association, now The Association
of the Nonwoven Fabrics Industry) and EDANA (European Disposables
And Nonwovens Association).
[0069] The terms "proximal" and "distal", unless
otherwise specified, refer respectively to the location of an element
of a structure near to or far from a central axis of the structure,
e.g., the proximal edge of a longitudinally extending element of
a structure is located nearer to the longitudinal axis of the structure
than the distal edge of the same element is located relative to
the same longitudinal axis.
[0070] Referring now to FIG. 1, an absorbent article, which can
be a training pant, an incontinence pad, a diaper, or other bodily
wrap, is illustrated as a pull-on garment 20 including a chassis
100. The chassis 100 includes a front waist region 36, a back waist
region 38, and a crotch region 37 disposed between the waist regions.
The waist regions 36 and 38 generally comprise those portions of
the garment 20 which, when worn, encircle the waist of the wearer.
The crotch region 37 is that portion of the garment 20 which, when
the garment 20 is worn, is generally positioned between the legs
of the wearer.
[0071] The chassis 100 defines a left side edge 137a and an opposing
right side edge 137b. A portion of the left side edge 137a (or region
adjacent the left side edge 137a) at the front waist region 36 is
pre-fastened to a portion of the left side edge 137a (or region
adjacent the left side edge 137a) at the back waist region 38 to
define a closed left side interface 119a that, in turn, defines
an encircled left leg opening 125a. Likewise, a portion of the right
side edge 137b (or region adjacent the right side edge 137b) at
the front waist region 36 is pre-fastened to a portion of the right
side edge 137b (or region adjacent the right side edge 137b) at
the back waist region 38 to define a closed right side interface
119b which, in turn, defines an encircled right leg opening 125b.
The side edges 137a-b, when fastened in the manner described above,
combine to form an encircled waist opening 144.
[0072] The chassis 100 further defines a front waist edge 136 in
the front waist region 36 and an opposing back waist edge 138 in
the back waist region 38. When the front waist region and back waist
region portions of the side edges 137a-b are fastened, a portion
of the chassis waist regions 36 and 38 defines a circumferential
belt region 33 that is disposed at or adjacent at least one of the
front and back waist edges 136 and 138. The circumferential belt
region 33 can abut the waist edges 136 and 138, or it can be spaced
below the waist edges. Generally, when the garment 20 is applied
to the wearer, the belt region 33 will be generally aligned with
the wearer's lower torso region (e.g., the upper waist region).
It should be appreciated, however, that the belt region 33 can be
disposed anywhere on the garment 20 that could benefit from fit
enhancement of the type described in more detail below.
[0073] Referring now to FIG. 2, the present invention recognizes
that the chassis 100 can be "extensible" which, as used
herein, refers to the ability to extend or stretch in a given direction
in an amount greater than 20% of its original dimension (including
both elastic and plastic deformation) when an extension force of
500 gm/inch is applied to the chassis in the direction of extensibility
without undergoing failure. For instance, when the chassis 100 is
said to be laterally extensible, the chassis 100 is capable of extending
in the lateral direction in an amount greater than 20% of its original
lateral dimension. It should be further appreciated that the term
"extensible" further encompasses a chassis having an extensibility
within a range whose lower end is defined by and between 20%, 25%,
and 30%, and whose upper end is defined by and between 40%, 60%,
80%, and 100% with respect to its original dimension along a given
direction. It should be furher appreciated that a portion of the
extension may result in elastic (i.e., returnable) deformation,
while additional extension, that beyond the yield point of the extensible
material results in plastic (i.e. permanent) deformation.
[0074] Alternatively, the chassis 100 can be configured substantially
non-extensible, it being appreciated that most materials exhibit
at least a nominal degree of extensibility. Accordingly, the term
"substantially non-extensible" as used herein refers to
a diaper whose chassis cannot achieve an extensibility (including
both elastic and plastic deformation) of greater than 20% of its
original dimension when subjected to a force of 500 grams in the
direction of the applied force without undergoing failure. For instance,
when the chassis 100 is said to be substantially laterally non-extensible,
the chassis 100 is incapable of extending in the lateral direction
more than 20% its original lateral dimension without ripping, tearing,
or the like. It should be further appreciated that the term "substantially
non-extensible" further encompasses extensibility no greater
than 15%, alternatively 10%, and alternatively still 5% its original
dimension. Methods for producing both non-extensible and substantially
extensible chassis are described in more detail below.
[0075] If the chassis 100 is laterally extensible, the chassis
100 will extend as the article is pulled up to the wearer's waist
region. For instance, as the pull-on garment 20 is applied to the
wearer, the chassis 100 can extend elastically up to the point at
which plastic deformation occurs. The present inventors envision
that a portion of the chassis 100 can elastically recover and exert
both frictional forces and normal forces against the wearer's waist
region up to the point of plastic deformation. While the present
inventors believe that the elastic recovery of the extensible chassis
can provide adequate fit about the wearer's waist region it may
not be sufficient for the purposes of preventing substantial sagging
during use, especially during active wear times. The present invention
recognizes that the overall fit of the garment 20 can be enhanced,
particularly at the wearer's waist region. For instance, a portion
of the chassis 100 that has been elastically or plastically deformed
during application can fit loosely about the waist region of the
wearer, which typically has a circumference less than that of the
wearer's hip region. The fit of the garment can be enhanced by a
fit enhancement member described hereinafter.
[0076] If the chassis 100 is substantially non-extensible, then
the chassis 100 should be configured such that the waist opening
144 should have a circumference large enough to pass over the wearer's
hips during application, which generally will cause the circumference
of the waist opening 144 to be greater than the circumference of
the wearer's waist region that typically engages the chassis 100
at the belt region 33. The present inventors recognize that such
a pull-on chassis 100 is not likely to achieve a fit at the wearer's
waist region that is sufficiently secure for the purposes of preventing
substantial sagging during use. The present invention therefore
recognizes that the overall fit of the garment 20 can be enhanced,
particularly at the wearer's waist region, by inclusion of a fit
enhancement member as will now be described.
Description of Belts for Fit Enhancement
[0077] Accordingly, referring to FIGS. 3A-C, certain aspects of
the present invention recognize that the pull-on garment 20 can
include a fit enhancement member, illustrated as an elongated belt
member 31, that is configured to provide a contractive force to
the belt region 33 of the chassis 100 (and hence to the wearer's
waist region). The belt 31 extends along a longitudinal belt axis
L-L (see FIG. 4) and can be configured to be substantially non-extensible
(e.g., formed from a non-extensible web material such as a nonwoven,
a film, a nonwoven and film laminate, or the like) along the longitudinal
belt axis L-L, or alternatively can be configured to be extensible
along the direction of the longitudinal belt axis L-L.
[0078] To render the belt 31 extensible, the belt 31 can be formed
from a web material that is preformed with longitudinally extending
regions in which the original material has been altered by embossing
or another method of deformation to create a pattern of generally
laterally oriented alternating ridges and valleys, as described
in U.S. Pat. No. 5,518,801 (issued May 21, 1996 to Chappell et al),
U.S. Pat. No. 5,691,035 (issued Nov. 25, 1997 to Chappell et al),
U.S. Pat. No. 5,723,087 (issued Mar. 3, 1998 to Chappell et al),
U.S. Pat. No. 5,891,544 (issued Apr. 6, 1999 to Chappell et al),
and U.S. Pat. No. 5,968,029 (issued Jan. 19, 1999 to Chappell et
al). The formed web material also includes longitudinally extending
unaltered regions located between the laterally oriented and longitudinally
extending altered regions. When the web is subsequently subjected
to an applied elongation along the longitudinal belt axis, the web
material exhibits an elastic-like behavior as it extends in the
direction of applied elongation and returns to its substantially
untensioned condition once the applied elongation is removed, unless
the web material is extended beyond the point of yielding, i.e.
the point of plastic deformation. This process is described in more
detail below with reference to FIG. 22. The web extensibility is
adjustable by varying the percentage of the web surface which is
comprised of the ridges and valleys.
[0079] If the belt 31 (or portions of the belt 31) is extensible,
the belt 31 (or the extensible portions) can be either pre-tensioned
prior to attachment to the chassis 100 or non pre-tensioned. If
the belt 31 is pre-tensioned, the belt 31 will apply a contractive
force to the chassis 100 that tends to reduce the circumference
of the waist opening 144. If the belt 31 is non pre-tensioned, the
belt 31 will not apply a contractive force until the belt region
33 (or other underlying chassis structure) is pulled over a structure
(e.g., the wearer's hip region) that extends the chassis 100 and
belt 31.
[0080] Alternatively, as described in more detail below, at least
a portion (or substantially all) of the belt 31 can be ring-rolled
and thus rendered extensible as described in U.S. Pat. No. 5,366,782
(issued Nov. 22, 1994 to Curro, et al).
[0081] As illustrated in FIG. 3A, the belt 31 includes attachment
zones 55 disposed at the opposing distal ends 59 of the belt 31
and adjacent the side edge 137 of the chassis 100. The attachment
zones 55 can comprise a permanent attachment such as a heat seal,
pressure weld, adhesive, cohesive, or other suitable permanent fastening
material. Alternatively, the attachment zones 55 can comprise an
adhesive, a cohesive, or mechanical fastener such as hooks or loops
that mate with corresponding loops or hooks on the chassis 100 to
provide an attachment zone that is releasably (and refastenably)
attached to the chassis 100. While the attachment zones 55 are preferably
disposed at the distal ends of the belt 31, it should be appreciated
that the zones 55 could alternatively be disposed anywhere along
the belt 31 that is inward of the distal ends such that the belt
31 can be reliably fastened to the garment 20. The belt 31 could
further include additional attachment zones disposed between the
outer attachment zones 55 if desired.
[0082] Referring to FIG. 3A, the belt 31 extends laterally across
the front waist region 36, and the attachment zones 55 are fastened
to the chassis 100 at a location adjacent, and in front of, the
closed side interfaces 119a-b. Alternatively, one or both of the
attachment zones 55 could be fastened to the chassis 100 at a location
further in front of the closed side interfaces 119a-b, i.e. closer
to the longitudinal chassis axis 42 (see FIG. 8) than illustrated
in FIG. 3A such that the belt 31 extends laterally across only a
portion of the width of the front waist region 36. Alternatively
still, the attachment zones 55 could be fastened to the chassis
100 behind the closed side interfaces 119a-b such that the belt
31 extends from one side of the back waist region 38 laterally across
the front waist region 36 and to the opposing side of the back waist
region 38. Alternatively still, one of the attachment zones 55 could
be disposed behind one of the side interfaces 119a-b while the other
attachment zone 55 could be disposed in front of the opposing side
interface such that the belt 31 extends laterally across a portion
of the front waist region 36 and a portion of the back waist region
38.
[0083] Referring to FIG. 3B, the attachment zones 55 can be fastened
to the chassis 100 at a location adjacent, and behind, the closed
side interfaces 119a-b such that the belt 31 extends laterally across
the back waist region 38. Alternatively, one or both of the attachment
zones 55 could be fastened to the chassis 100 at a location farther
behind the closed side interfaces 119a-b (i.e., closer to the longitudinal
chassis axis 42) than illustrated in FIG. 3B such that the belt
31 extends laterally across only a portion of the back waist region
38. Alternatively, one or both the attachment zones 55 could be
fastened to the chassis 100 in front of the closed side interfaces
119a-b such that the belt 31 extends laterally across the back waist
region 38 and a portion of the front waist region 36.
[0084] Referring now to FIG. 3C, the belt 31 can alternatively
provide one attachment zone 55 disposed adjacent, and behind, one
of the side interfaces, such as the right side interface 119b as
illustrated, while the other attachment zone 55 is disposed adjacent,
and in front of, the same side interface 119b such that the belt
31 is disposed substantially at the side of the wearer and in an
overlapping relationship with the side interface. Alternatively,
or additionally, a second belt can be provided overlapping the opposing
side interface having one attachment zone fastened to the chassis
100 at a location adjacent, and behind, the left side interface
119a while the other attachment zone is fastened to the chassis
100 at a location adjacent, and in front of, the same side interface
119a. The attachment zones may also be disposed laterally inward
from the side interfaces, i.e. closer to the longitudinal centerline
of the chassis, in either the front waist region, back waist region
or both front and back waist regions.
[0085] Referring now to FIG. 4, the belt 31 can be tightened to
enhance the fit of the garment 20 applied to a wearer. Specifically,
once the pull-on garment 20 has been applied to the wearer, the
user can manually release one of the attachment zone(s) 55 from
the chassis 100, apply a tension inducing force to the belt 31 (i.e.,
by pulling one belt end in a direction away from the opposing belt
end along the direction of Arrow A), and re-fastening the released
attachment zone 55 to the chassis 100. It should be appreciated
that reattachment of the released attachment zone 55 can draw additional
chassis material under the belt 31 such that the belt 31 can overlap
a greater portion of the chassis periphery compared to the portion
of chassis periphery overlapped by the belt prior to releasing the
attachment member 55. The resulting tension induced in the belt
31 causes the belt 31 to apply a fit enhancing contractive force
to the chassis 100.
[0086] It should be appreciated that one attachment zone 55 can
be permanently attached to the chassis 100 and that the other attachment
zone 55 can be releasably (and refastenably) attached to the chassis
100. Visible indicia can be provided that indicates to the user
which attachment zone is releasably and refastenably attached to
the chassis 100 and, hence, can be adjusted. Alternatively, both
attachment zones 55 can be releasably and refastenably attached
to the chassis and adjustable. In certain embodiments comprising
a belt wherein both outwardly disposed attachment zones are releasable
and refastenable the belt may further comprise attachment zones
disposed intermediate the outwardly disposed attachment zones.
[0087] Referring now to FIGS. 5A, the belt 31 constructed in accordance
with any of the embodiments illustrated and described above with
respect to FIGS. 3A-C can include a frangible joint 49 disposed
between two attachment zones 55 positioned in any location described
above. The frangible joint 49 is defined as an area or region that
is weaker than the surrounding belt regions such that the frangible
joint 49 provides a natural tear path when an appropriate force
is applied to the belt 31. For instance, the frangible joint 49
can comprise a perforation that can be easily and reliably torn
manually by the wearer or caregiver as desired. Referring also to
FIG. 6, the present invention appreciates that the frangible joint
49 can be included in a belt 31 that defines a circumferential member
surrounding the entire periphery of the chassis 100. The belt 31
can be secured to the chassis 100 via frictional and contractive
belt forces, or the belt 31 can be permanently or removably attached
to the chassis 100 via any suitable attachment members of the type
described above.
[0088] It should be appreciated that the frangible joint 49 can
be disposed substantially equidistant from the side edges 137a and
137b in either the front or back waist region (or in both regions
if two belts 31 are used, or if one circumferential belt is used
having two frangible joints). Alternatively, the frangible joint
49 can be disposed closer to one side edge than the other, or the
frangible joint 49 can be disposed adjacent one of the side edges
137a and 137b.
[0089] At least one fastening zone 57 can be disposed adjacent
the frangible joint 49, and can be disposed on the inner (i.e.,
body-facing) surface of the belt 31 and/or the outer (i.e., garment-facing)
surface of the belt 31. As illustrated in FIG. 5A, the fastening
zones 57 are disposed on either side of the frangible joint 49 and
can comprise any shape or size as desired. The fastening zones 57
can comprise an adhesive, a cohesive, hooks or loops configured
or a slot to attach to corresponding loops or hooks, a button, corresponding
cohesive surface or any alternative permanent or releasable (and
re-fastenable) fastener. If the fastening zones comprise an adhesive
or cohesive, a peelable backing can be provided to cover the adhesive
or cohesive prior to use as is known by those having ordinary skill
in the art. The fastening zones 57 may be of any shape or size to
enable adjustment of the belt for proper fit. The fastening zones
57 may cover only a portion of one or both or the belt surfaces
or alternatively may cover the full extent of one or both of the
belt surfaces.
[0090] Referring to FIG. 5B, when the frangible joint 49 is torn,
the belt 31 defines a pair of opposing free ends 53a and 53b disposed
proximally relative to the attachment zones 55. By "free end",
as used herein, the present invention refers to the ends 53a and
53b being separate or free from each other. Opposing ends of a continuous
belt would also be considered to be free ends. The free ends 53a
and 53b may or may not be free from the chassis, as is described
in more detail below. If the belt 31 is configured as illustrated
in FIG. 6, then only one belt segment defines free outer ends 53a
and 53b. If the belt 31 is configured as illustrated in FIGS. 3A-3C,
then breaking the frangible joint 49 separates the belt 31 into
first and second belt segments 51a and 51b, each of which defining
a corresponding free outer end 53a and 53b. Because the frangible
joint 49 illustrated in FIG. 5A extends substantially vertically,
or perpendicular to the longitudinal belt axis L-L (shown in FIG.
4), the outer edges of free ends 53a and 53b also extend substantially
vertically and parallel to each other (when the segment(s) 51a-b
extend along the longitudinal belt axis L-L).
[0091] Referring now to FIGS. 5C-E, once the frangible joint 49
has been broken, the belt 31 can be tightened and refastened to
apply a contractive force to the underlying chassis 100 at the belt
region 33. For instance, as illustrated in FIG. 5C, the free ends
53a and 53b can be drawn together until they overlap each other,
and subsequently fastened via the fastening zone(s) 57 in an interior-to-exterior
surface connection (in this regard, the free ends 53a and 53b are
said to be attached to each other). Specifically, the fastening
zone 57 of one segment can be attached to the fastening zone 57
of the other segment (for instance if the two fastening zones 57
define a hook-and-loop or any alternative connection). Alternatively,
the fastening zone 57 of one segment can be attached to the web
material of the opposing segment. It should be appreciated that
drawing the free ends 53a and 53b of a non-extensible belt in a
direction away from their respective attachment zones 55 introduces
tension in the belt 31. Alternatively, referring to FIG. 5D, once
the frangible joint 49 has been broken, the belt 31 can be tightened
and one or both of the fastening zones 57 of the belt segments 51a
and 51b can be fastened to the chassis 100. In order to avoid interference
between the two belt segments 51a-b when both are designed to be
joined to the chassis 100 and thereby permit independent connection
to the chassis 100, the belt segments can be vertically offset such
that both fastening zones 57 have clearance and can be attached
to the chassis 100.
[0092] Alternatively still, referring to FIG. 5E, the belt 31 can
be pre-fastened to the chassis 100 at one location adjacent the
frangible joint 49. Accordingly, once the joint 49 is broken, only
one segment (belt segment 51a as illustrated) is free from the chassis
100 and can be attached to the opposing belt segment 51b as illustrated,
or can be attached to the chassis 100 as illustrated in FIG. 5D.
[0093] Alternatively still, referring to FIG. 5F, once the joint
49 is broken, the user can elect to tighten the belt 31 and tie
the belt segments 51a and 51b in any desired knot. It should be
appreciated that the belt segments 51a and 51b can be tied in this
manner regardless of whether or not belt 31 includes fastening zones
57.
[0094] Referring now to FIGS. 7A-D, it should be appreciated that
the frangible joint 49 can assume any configuration as desired.
For instance, instead of extending substantially perpendicular to
longitudinal belt axis L-L as illustrated in FIG. 5A, FIG. 7A illustrates
the frangible joint 49 as extending substantially parallel to longitudinal
belt axis L-L. As illustrated in FIG. 7B, the frangible joint 49
can span up to the entire distance between opposing side interfaces
119a and 119b. Specifically, the frangible joint 49 extends between,
and terminates at or adjacent, the opposing vertical edges of belt
31 or opposing horizontal edges of the belt 31 such that the joint
49 is easily accessible to the user. If, for instance, both opposing
ends of the frangible joint 49 extended to the same belt edge, a
cutout would be formed when the frangible joint 49 is broken instead
of two discrete belt segments. The frangible joint 49 can overlap
the attachment zones 55 such that a portion of the attachment zones
55 continue to fasten the belt segments to the chassis, while a
portion of the attachment zones 55 is detached and provide fastening
zones 57 for the belt segments that are formed after the frangible
joint 49 has been broken. As illustrated in FIG. 7C, the frangible
joint 49 can terminate inward of one or both side interfaces 119a
and 119b. The elongated frangible joint 49 illustrated in FIGS.
7B-C provides elongated belt segments that are particularly configured
to be tied together in a knot.
[0095] Alternatively still, as illustrated in FIG. 7D, the frangible
joint 49 can extend in a direction that defines an angle a between
0 and 90 degrees with respect to the longitudinal belt axis L-L.
In one aspect of the invention, the angle .alpha. is between 5 and
45 degrees, and alternatively between 5 and 30 degrees. Higher angles
formed between the frangible joint 49 and the longitudinal axis
L-L provide greater vertical space at the outer ends of the belt
segments that can be occupied by fastening zones 57, while lower
angles increase the length of the belt segments. For instance, if
the resulting belt segments are to be tied in a knot, the angle
.alpha. can be within the range of 1 and 20 degrees. As described
above with respect to FIGS. 6A-C, the frangible joint 49 can span
the entire distance between opposing side interfaces 119a and 119b,
or the frangible joint 49 can terminate at a position inward of
one or both side interfaces.
[0096] It should be appreciated that the above examples are only
illustrative of exemplary embodiments, and that the frangible joint
49 can assume any geometric configuration as desired to produce
corresponding belt segments that can be attached to either each
other or the chassis, or tied together in a knot. For instance,
while the frangible joint 49 has been illustrated as extending substantially
equidistantly between the upper and lower edges of the belt 31,
the joint 49 could alternatively be offset towards one of the edges
if, for instance, one belt segment was intended to remain secured
to the chassis while the other belt segment formed a free end having
a sufficient area for a fastening zone 57.
[0097] As described above, both the chassis 100 and the belt member
31 can be rendered extensible or substantially non-extensible in
the direction of the longitudinal belt axis L-L. The operation of
the belt 31 can depend on whether the chassis 100 and/or the belt
31 is extensible, as will now be described with reference to FIGS.
3A-3C, 4, 5A-5F and 6, it being appreciated that the operation of
belt 31 is equally applicable to any of the configurations illustrated
in FIGS. 7A-D or their alternatives.
[0098] If, for instance, the chassis 100 is extensible and the
belt 31 is substantially non-extensible, then the belt region 33
can be configured to have a relaxed length, or alternatively an
extended length, large enough to pass over the wearer's hips during
application. Alternatively, if the belt 31 has a length and position
that prevents the chassis 100 from being extended such that it can
be pulled up to the wearer's waist, the frangible joint 49 can be
broken prior to, or during, application of the garment 20 such that
the belt region 33 of the chassis 100 can be extended as it passes
over the wearer's hips. Once the garment 20 has been pulled into
position at the wearer's waist, the belt 31 can be tightened to
create a contractive belt force that is applied to the chassis 100
to enhance the fit of the garment 20 at the wearer's waist when
the outer end(s) 53a-b are fastened to the chassis 100 or to each
other. It should be appreciated that, because the wearer's waist
may have a circumference greater than the belt 31 could accommodate
before the frangible joint 49 was broken, the free ends 53a and
53b may be longitudinally spaced from each other even after they
are drawn toward each other and attached to the chassis 100. If,
on the other hand, the belt 31 defines a length that is sufficient
to allow the chassis 100 to be extended in order to pass over the
wearer's hips during application of the garment 20 the user need
not break the frangible joint 49 until the garment 20 has been applied
to the wearer's waist.
[0099] As another example, if both the chassis 100 and the belt
31 are extensible, the chassis 100 can define an extended circumference
at the belt region 33 that is large enough to fit over the wearer's
hips during application. If the belt 31 defines an extended length
that is great enough to fit over the wearer's hips, the garment
20 can be applied to the wearer and positioned at the waist before
the frangible joint 49 is broken. Once the frangible joint 49 is
broken, the belt 31 can then be extended by pulling at least one
of the free ends 53a and 53b away from its corresponding attachment
zone 55 to provide a compressive belt force that is applied to the
chassis. The outer end(s) 53a and 53b can then be fastened as desired.
Alternatively, if the belt 31 is less extensible than the chassis
100 such that the chassis 100 cannot be extended to fit over the
wearer's hips during application of the garment 20, then the user
can break the frangible joint 49 prior to, or during, application
of the garment 20. One skilled in the art will recognize that the
frangible joint 49 can, if desired, be broken before or during the
application of the garment 20 to the wearer even if the belt 31
is of sufficient length or is sufficiently extensible to accommodate
the wearer's hips and/or waist region during application of the
garment 20. It should be appreciated that the belt 31 can be provided
in a pre-tensioned state that provides an initial contractive force
to the chassis 100, in which case the chassis 100 will have a contracted
waist opening 144.
[0100] As yet another example, if both the chassis 100 and the
belt 31 are substantially non-extensible, the chassis 100 can be
provided having a circumference in the waist region that is at least
substantially equal to that of the wearer's hips. If the belt 31
has a sufficient length so as to not restrict the chassis 100 from
being pulled over the wearer's hips, the user will have the option
of breaking the frangible joint 49 after the garment 20 has been
pulled into position at the wearer's waist. Alternatively, if the
belt 31 has a length that limits the size of the chassis 100 in
the waist region such that the belt prevents the chassis 100 from
being pulled over the wearer's hips, the user can break the frangible
joint prior to, or during, the application of the garment 20 to
the wearer, and subsequently tighten and fasten the free end (s)
53a-b once the garment 20 has been positioned such that the belt
31 is aligned with the wearer's waist.
[0101] As still another example, if the chassis 100 is substantially
non-extensible and the belt 31 is extensible, the chassis 100 will
define a circumference sufficient to allow the chassis to pass over
the wearer's hips during application of the garment 20. If the belt
31 is not pre-tensioned, then the garment 20 will fit over the wearer's
hips, and the frangible joint 49 can be broken once the garment
20 has been properly positioned at the wearer's waist (or beforehand
if desired). Furthermore, the belt 31 can be pre-tensioned and can
define an unextended length that is less than that required to enable
the belt 31 and chassis 100 to be pulled over the hips of the wearer
without extension of the belt 31. Alternatively, or additionally,
the pre-tensioned belt 31 may apply a contractive force to the chassis
100 which, in turn, defines a contracted waist opening 144 that
cannot be easily extended to fit over the wearer's hips during application
of the garment. In this case, the frangible joint 49 should be broken
prior to, or during, application of the garment 20. If the belt
31 is sufficiently extensible to allow the belt and chassis to be
pulled over the hips of the wearer, the frangible joint 49 can be
broken once the garment 20 has been properly positioned at the wearer's
waist (or beforehand if desired).
Examples of Exemplary Disposable Pull-On Garments
[0102] As shown in FIGS. 8-13, one end portion of an absorbent
article, illustrated as an exemplary pant-like garment, also referred
to as a pant or a pull-on garment 20, is configured as a front waist
region 36. The longitudinally opposing end portion of the pull-on
garment 20 is configured as a back waist region 38. An intermediate
portion of the pull-on garment 20 extending longitudinally between
the front waist region 36 and the back waist region 38 is configured
as a crotch region 37.
[0103] The chassis 100 has a longitudinally extending left side
edge 137a and a laterally opposing and longitudinally extending
right side edge 137b, both chassis side edges extending longitudinally
between the front waist edge 136 and the back waist edge 138. The
chassis 100 has an interior surface 102 and an exterior surface
104. The chassis 100 also has a longitudinal chassis axis 42 (extending
generally parallel to the lateral axis T of the belt 31) extending
equidistantly between side edges 137a and 137b, and a lateral chassis
axis 44 extending perpendicular to longitudinal chassis axis 42
(extending generally parallel to the longitudinal belt axis L-L)
extending equidistantly between end edges 136 and 138. The longitudinal
chassis axis 42 extends through the midpoint of the front waist
edge 136 and through the midpoint of the back waist edge 138 of
the chassis 100. The lateral chassis axis 44 extends through the
midpoint of the left side edge 137a and through the midpoint of
the right side edge 137b of the chassis 100. The exemplary chassis
100 shown in FIG. 8 additionally has longitudinally extending and
laterally opposing side flaps 147a and 147b that are described in
more detail below.
[0104] The basic structure of the pull-on garment 20 also includes
an absorbent assembly 200 that is attached to the chassis 100. The
absorbent assembly 200 has a laterally extending front edge 236
in the front waist region 36 and a longitudinally opposing and laterally
extending back edge 238 in the back waist region 38. The absorbent
assembly 200 has a longitudinally extending left side edge 237a
and a laterally opposing and longitudinally extending right side
edge 237b, both absorbent assembly side edges extending longitudinally
between the front edge 236 and the back edge 238. The absorbent
assembly 200 has an interior surface 202 and an exterior surface
204. The absorbent assembly 200 can be disposed symmetrically with
respect to either or both of the longitudinal chassis axis 42 and
the lateral chassis axis 44. Alternatively, the absorbent assembly
200 can be disposed asymmetrically with respect to either or both
of the longitudinal chassis axis 42 and the lateral chassis axis
44. For example, the absorbent assembly 200 shown in FIG. 8 is disposed
symmetrically with respect to the longitudinal chassis axis 42 and
asymmetrically with respect to the lateral chassis axis 44. In particular,
the absorbent assembly 200 shown in FIG. 8 is disposed asymmetrically
toward the front waist region 36.
[0105] The respective front edge 236, back edge 238, left side
edge 237a, and right side edge 237b of the absorbent assembly 200
can lie inward of the respective front waist edge 136, back waist
edge 138, left side edge 137a, and right side edge 137b of the chassis
100, as in the exemplary pull-on garment 20 shown in FIG. 8. Such
a configuration in which one or more of the edges of the absorbent
assembly 200 lies inward of the corresponding edges of the chassis
100 may be desirable, for example, in order to allow the relatively
more flexible layer or layers adjacent to the edges of the chassis
to conform to the body of the wearer and thereby form effective
gasket-like seals against the skin of the wearer without being constrained
by a relatively thicker and relatively less flexible absorbent assembly.
Alternatively, one or more of the edges of the absorbent assembly
200 can coincide with the corresponding edge or edges of the chassis
100.
[0106] The closed side interfaces 119a-b, in part, define the continuous,
closed, left and right leg openings 125a and 125b, respectively,
and a continuous, closed, waist opening 144, adapted to fit and
gasket the wearer's legs and waist, respectively, as the garment
20 is pulled up to the wearer's lower torso region. The side interfaces
119a-b can be formed into a closed configuration in accordance with
any known techniques or methods known in the art. For instance,
the interfaces 119a and 119b can be formed with a seam, which may
include a bond formed by heat sealing such as ultrasonic bonding,
high pressure bonding, RF (radio frequency) bonding, hot air bonding,
heated point bonding, and the like as appreciated by one having
ordinary skill in the art. Various suitable pant configurations
are disclosed in U.S. Pat. No. 5,246,433 (issued on Sep. 21, 1993
to Margaret H. Hasse, et al); U.S. Pat. No. 5,569,234 (issued on
Oct. 29, 1996 to Kenneth B. Buell, et al); U.S. Pat. No. 6,120,487
(issued on Sep. 19, 2000 to Gregory Ashton); U.S. Pat. No. 6,120,489
(issued on Sep. 19, 2000 to Larry Johnson, et al); U.S. Pat. No.
4,940,464 (issued on Jul. 10, 1990 to Paul T. Van Gompel); U.S.
Pat. No. 5,092,861 (issued on Mar. 3, 1992 to Hironori Nomura et
al); U.S. Pat. No. 5,897,545 (issued on Apr. 27, 1999 to Mark James
Kline, et al); U.S. Pat. No. 5,957,908 (issued on Sep. 28, 1999
to Mark James Kline, et al); and U.S. Patent Publication No. 2003/0233082
A1 (published on Dec. 18, 2003 to Mark J. Kline, et al).
[0107] Alternatively, the closed side interfaces 119a-b can be
formed as disclosed in U.S. Pat. No. 5,779,831 (issued on Jul. 14,
1998 to Christoph Schmitz); U.S. Pat. No. 5,772,825 (issued on Jun.
30, 1998 to Christoph Schmitz); U.S. Pat. No. 5,607,537 (issued
on Mar. 4, 1997 to Larry Johnson, et al); U.S. Pat. No. 5,622,589
(issued on Apr. 22, 2997 to Larry Johnson, et al); U.S. Pat. No.
5,662,638 (issued on Sep. 2, 1997 to Larry Johnson, et al); U.S.
Pat. No. 6,042,673 (issued on Mar. 28, 2000 to Larry Johnson, et
al); and U.S. Pat. No. 6,726,792 (issued on Apr. 27, 2004 to Larry
Johnson, et al). Various processing methods are well known in the
art to provide absorbent pull-on garments. One such process utilizes
a final knife followed by a reciprocating tucker blade that pushes
the pad from a horizontal orientation to a vertical orientation
and a vacuum conveyor belt that holds the pad through a high pressure
side seaming unit. The side seaming unit is followed by a slitter
that trims the pant edges to provide a finished seam edge. An alternative
method disclosed in the aforementioned patents involves cutting
the pad in the final knife and bi-folding the pad collecting the
pads in a "waterwheel" stacker (a rotary slotted wheel).
The bonding is accomplished while the pad is held in place on the
rotating wheel.
[0108] Alternatively, referring to FIGS. 8 and 14A, a left side
edge region 145a (defined as a region adjacent the left side edge
137a and including the left side edge 137a) at the front left attachment
zone 143a (i.e., in the front waist region 36) can be overlapped
with the left side edge region 145a at the back attachment zone
150a (i.e., in the back waist region 38) in an interior surface-to-exterior
surface (or vice versa) configuration. Likewise, a right side edge
region 145b (defined as a region adjacent the right side edge 137b
and including the right side edge 137b) at the front right attachment
zone 143b (i.e., in the front waist region 36) can be overlapped
with the right side edge region 145b at the back attachment zone
150b (i.e., in the back waist region 38) in an interior surface-to-exterior
surface (or vice versa) configuration. Accordingly, the left and
right side interfaces 119a and 119b can be closed by attaching the
overlapping attachment zones 143 and 150 via any suitable permanent
or refastenable closure member 127, such as a seam of the type described
above, or an adhesive, a cohesive, a tab-and-slot configuration,
or via hook-and-loop attachments. It should be appreciated that
joining the side edge regions 145a and 145b causes the side edges
137a and 137b to correspondingly be joined indirectly via the side
edge regions 145a and 145b.
[0109] Alternatively, referring to FIGS. 8 and 14B, the closed
side interfaces 119a and 119b are formed by bi-folding the chassis
100 such that the left and right side edge regions 145a-b, in the
front waist region adjacent the front waist edge 136, overlap the
left and right side edge regions 145a-b, respectively, in the back
waist region adjacent the back waist edge 138 in an interior-to-interior
surface configuration. In this configuration, the front waist edge
136 can be substantially aligned with the back waist edge 138 and
the side edge 137a in the front and back waist regions can also
be substantially aligned as can be the front and back waist regions
of side edge 137b. The folded chassis 100 is then attached to the
side edge regions 145a-b at the attachment zones 143 and 150, respectively
(FIG. 8), using any suitable permanent or refastenable closure member
127, thereby forming a pull-on garment defining continuous left
and right leg openings 125a and 125b, respectively, and a continuous,
closed, waist opening 144.
[0110] Alternatively still, referring to FIGS. 8 and 14C, the closed
side interfaces 119a and 119b can be formed by bi-folding chassis
100 such that the left and right side edge regions 145a-b, adjacent
the front waist edge 136, overlap the left and right side edge regions
145a-b, respectively, adjacent the back waist edge 138 in an exterior-to-exterior
surface configuration. In this configuration, the front end edge
136 can be substantially aligned with the back end edge 138. The
folded chassis 100 is then attached at the side edge regions 145a-b
at the attachment zones 143 and 150, respectively (FIG. 8), using
any suitable permanent or refastenable closure member 127, thereby
forming a pull-on garment defining continuous left and right leg
openings 125a and 125b, respectively, and a continuous, closed,
waist opening 144.
[0111] Furthermore, one having ordinary skill in the art will appreciate
that the side interfaces 119a-b can be closed via a refastenable
closure member that can be nondestructively opened and refastened.
Examples of refastenable closure members include hook-and-loop fasteners,
snaps, tab-slot fasteners, cohesives, peelable adhesives and the
like.
[0112] Examples of closure members are described in U.S. Pat. No.
6,432,098 (issued Aug. 13, 2002 to Kline et al); U.S. Pat. No. 6,880,211
(issued Apr. 19, 2005 to Jackson et al); and U.S. Patent Publication
No. 2003/0233082 (published Dec. 18, 2003 to Kline et al).
[0113] The term "pre-closed" refers to an absorbent article
that can be closed by the end user and formed into a pant-like garment
prior to applying the garment to the wearer. The term "pre-formed"
refers to an absorbent article that has been formed into a pant-like
garment in the packaging such that the end user receives the article
as a pant-like garment that can be directly applied to the wearer.
[0114] Referring now to FIG. 14D, the belt 31 can be attached to
the chassis 100 prior to creation of the corresponding side interfaces
(illustrated as left side interface 119a. Specifically, the back
waist portion of left side edge 137a is attached to the belt 31
at the attachment zone 55, and the attachment zone 55 is in turn
attached to the front waist portion of the left side edge 137a such
that the front and back waist portions of the left side edge 137a
are indirectly attached via the belt 31. Alternatively, or additionally,
the front waist portion of the left side edge 137a can be attached
to the back waist portion of the left side edge 137a. While FIG.
14D illustrates the belt 31 being integrated into the side interface
119a formed in an exterior-to-exterior surface configuration of
the type shown in FIG. 14C, it should be appreciated that the belt
31 could instead be formed in any type of closed interface appreciated
by one having ordinary skill in the art.
[0115] It should be further appreciated that the belt 31 could
be attached to the chassis 100 prior to formation of one or both
of the side flaps 147a and 147b and therefore folded inward when
the side flaps are formed, or alternatively the belt 31 may be attached
to the chassis after formation of one or both of the side flaps
whereby the belt can be folded inward in an overlapping relationship
with the side flaps. In both of these embodiments, once the chassis
is formed into a pull-on pant, the belt can be positioned within
one or both of the closed side interfaces 119a-b.
[0116] In embodiments in which the belt 31 is in both the front
waist region and back waist region, specifically when the belts
31 are disposed at the waist end edges 136 and 138, the belt 31
can be added to the chassis 100 prior to the final knife which is
the process step that separates the continuous web of chassis into
individual discrete products, thereby severing the belt 31 such
that the belt 31 is separated into a front belt portion on one chassis
and rear belt portions on a separate previously attached chassis.
Description of the Chassis
[0117] Referring also to FIGS. 15-20, the chassis 100 is shown
laid out flat before the side flaps 147a and 147b are formed by
folding portions of the chassis 100 laterally inward, i.e., toward
the longitudinal chassis axis 42, to form both the respective side
flaps 147a and 147b and the side edges 137a and 137b of the chassis
100 as shown in FIGS. 8-13. In this condition of being laid out
flat, the chassis 100 has a longitudinally extending left outer
side edge 155a and a laterally opposing and longitudinally extending
right outer side edge 155b. Both of these chassis outer side edges
extend longitudinally between the front waist edge 136 and the back
waist edge 138. As is described in more detail below, when the side
flaps 147a and 147b are formed by folding portions of the chassis
100 laterally inward, the outer side edges 155a and 155b of the
chassis form respective proximal edges 157a and 157b of the side
flaps 147a and 147b.
[0118] The chassis 100 includes a water-impermeable backsheet 26
defining an exterior surface that is intended to be placed toward
clothing that is worn over the pull-on garment 20. The backsheet
26 can be formed from films of polyethylene and other polyolefins,
or can alternatively be formed as multi-layer structures, such as
laminates of a film and a nonwoven, or alternatively as a dual layer
nonwoven laminate as understood by one having ordinary skill in
the art. A laminate backsheet can be oriented with the nonwoven
disposed exteriorly to provide the feel and appearance of a more
cloth-like outermost layer than would be provided by using the film
as the outermost layer.
[0119] The chassis 100 can further include an inner liner 22 attached
to the backsheet 26. As illustrated in FIGS. 15-16, the inner liner
22 can extend to the same width and the same length as the backsheet
26. The inner liner 22 can form a portion of the interior surface
102 of the chassis 100 that is intended to be placed against the
body of the wearer. Accordingly, the inner liner 22 can be formed
of a soft material that will not irritate the skin of the wearer,
and can serve to isolate the skin of the wearer from a portion of
the backsheet 26. This may be desired, for instance, when the pull-on
garment 20 is worn under conditions in which contact between the
skin and a backsheet film could be uncomfortable. Many suitable
materials for the inner liner 22 are well known in the art, including
rayon and synthetic nonwovens such as spunbonded or carded polypropylene,
polyethylene or polyester.
[0120] In accordance with an alternative embodiment, one or more
of the edges of the inner liner 22 can lie inward of the edges of
the backsheet 26. For example, referring to FIG. 8, only the portions
of the inner liner 22 lying in the gaps between the front edge 236
of the absorbent assembly 200 and the front waist edge 136 of the
chassis 100 and between the back edge 238 of the absorbent assembly
200 and the back waist edge 138 of the chassis 100 are exposed,
while the remainder of the inner liner 22 is covered by the absorbent
assembly 200 and the side flaps 147a and 147b. Therefore, a laterally
extending strip of the inner liner 22 disposed in the gap in the
front waist region 36 and a similar laterally extending strip of
the inner liner 22 disposed in the gap in the back waist region
38 can suffice to isolate the skin of the wearer from the backsheet
26 in these two gaps.
[0121] As shown in FIGS. 8-13, the chassis 100 includes longitudinally
extending and laterally opposing side flaps 147a and 147b that are
disposed on the interior portion of the garment 20. The side flaps
147a and 147b can be formed by folding portions of the chassis 100
laterally inward to form both the respective side flaps 147a and
147b and the side edges 137a and 137b of the chassis 100. Alternatively,
the side flaps 147a and 147b can be formed by attaching an additional
layer or layers to the chassis 100 at or adjacent to each of the
respective side edges 137a and 137b of the chassis 100.
[0122] Portions of a film backsheet 26 that are folded laterally
inward to form the side flaps can contact the skin of a wearer during
the use of the pull-on garment 20. However, the alternating ridges
and valleys in such a film backsheet that has been deformed in order
to make it extensible can provide channels through which air can
pass to alleviate any concern regarding such contact of the film
backsheet with the skin.
[0123] In embodiments in which portions of the chassis 100 are
folded laterally inward to form the side flaps 147a and 147b, the
chassis 100 can simply be folded loosely or can be creased along
a portion of each of its side edges 137a and 137b. For example,
it may be desirable to form creases along portions of the side edges
137a and 137b in the crotch region 37 in order to impart a more
finished appearance to the garment 20. Alternatively or in addition
to creasing, a portion of each of the folded side flaps 147a and
147b adjacent to the side edges 137a and 137b can be attached to
the interior surface 102 of the chassis 100 to achieve a similar
result.
[0124] The left side flap 147a defines a proximal edge 157a and
the right side flap 147b defines a proximal edge 157b. In the exemplary
garment 20 shown in FIG. 8, the proximal edge 157a and the proximal
edge 157b lie laterally inward of the respective left side edge
237a and right side edge 237b of the absorbent assembly 200, and
the left side flap 147a and the right side flap 147b thus overlap
the absorbent assembly 200. Such an overlapped configuration may
be desirable in order to impart a more finished appearance to the
garment 20 than that imparted by a non-overlapped configuration.
Alternatively, the left side flap 147a and the right side flap 147b
do not overlap the absorbent assembly 200, for instance when the
proximal edge 157a and the proximal edge 157b lies laterally outward
of the respective left side edge 237a and right side edge 237b of
the absorbent assembly 200.
[0125] Referring again to FIG. 8, the left side flap 147a and the
right side flap 147b extend the full length of the chassis 100 between
the front waist edge 136 and the back waist edge 138. Such a full
length configuration may be desirable in order to minimize the amount
of waste material and the difficulty associated with the manufacture
of the pull-on garment 20, especially when the method used to manufacture
the garment 20 requires the introduction of the material or materials
for the chassis 100 in the form of a continuous web or multiple
continuous webs. Alternatively, the side flaps can be shorter and
extend less than the full distance between the front waist edge
136 and the back waist edge 138. Such a shorter configuration may
be desirable in order to minimize the total amount of material used
in the manufacture of the pull-on garment 20.
[0126] Each of the side flaps 147a and 147b is attached to the
interior surface 102 of the chassis 100 in attachment zones located
in the front waist region 36 and in the back waist region 38. For
example, the side flaps 147a and 147b are attached to the interior
surface 102 of the chassis 100 in front longitudinally oriented
adhesive attachment zones 151 and back longitudinally oriented adhesive
attachment zones 152 (more clearly visible in FIG. 15). In particular,
the left side flap 147a is attached to the interior surface 102
of the chassis 100 in opposing longitudinally oriented adhesive
attachment zones 151a and 152a. Attachment zone 151a is disposed
adjacent the proximal edge 157a of left side flap 147a near the
front waist edge 136, and attachment zone 152a is disposed adjacent
the proximal edge 157a near the back waist edge 138. Similarly,
the right side flap 147b is attached to the interior surface 102
of the chassis 100 in opposing longitudinally oriented adhesive
attachment zones 151b and 152b. Attachment zone 151b is disposed
adjacent the proximal edge 157b of right side flap 147b near the
front waist edge 136, and attachment zone 152b is disposed adjacent
the proximal edge 157b near the back waist edge 138. The adhesive
attachment zones can have equal areas or can be unequal in area.
For example, the front longitudinally oriented adhesive attachment
zones 151a and 151b can be of one size and the back longitudinally
oriented adhesive attachment zones 152a and 152b can be of another
size.
[0127] Additionally, or alternatively, the side flaps 147a and
147b can be attached to front and back laterally oriented adhesive
attachment zones 153 and 154, respectively. Specifically, the left
side flap 147a is attached to the interior surface 102 of the chassis
100 in opposing laterally oriented adhesive attachment zone 153a
and 154a. Adhesive zone 153a is disposed adjacent the front waist
edge 136 and adhesive attachment zone 154a is disposed adjacent
the back waist edge 138. Similarly, the right side flap 147b is
attached to the interior surface 102 of the chassis 100 in opposing
laterally oriented adhesive attachment zones 153b and 154b. Attachment
zone 153b is disposed adjacent the front waist edge 136 and attachment
zone 154b is disposed adjacent to the back waist edge 138. The adhesive
attachment zones can have equal areas or can be unequal in area.
For example, the front laterally oriented adhesive attachment zones
153a and 153b can be of one size and the back laterally oriented
adhesive attachment zones 154a and 154b can be of another size.
[0128] Alternatively, each attachment zone can extend laterally
across the full width of the respective side flap. For example,
a laterally oriented adhesive attachment zone can extend laterally
from the chassis left side edge 137a to the left side flap edge
157a and thereby attach the entire width of the left side flap 147a
adjacent to the front waist edge 136 to the interior surface 102
of the chassis 100. In embodiments in which the front edge 236 or
the back edge 238 of the absorbent assembly 200 coincides with the
respective front waist edge 136 or back waist edge 138 of the chassis
100 and the side flaps 147a and 147b overlap the absorbent assembly
200, the side flaps 147a and 147b can be attached to the absorbent
assembly 200 instead of, or in addition to, being attached to the
interior surface 102 of the chassis 100.
[0129] Between the attachment zones, the proximal edges 157a and
157b of the side flaps 147a and 147b remain unattached to the interior
surface 102 of the chassis 100 or to the absorbent assembly 200.
Also between the attachment zones, each side flap preferably includes
a longitudinally extensible flap elastic member that is attached
adjacent to the proximal edge of the side flap by any of many well-known
means. Each such flap elastic member can be attached over its entire
length or over only a portion of its length. For example, such a
flap elastic member can be attached only at or near its longitudinally
opposing ends and can be unattached at the middle of its length.
Such a flap elastic member can be disposed in the crotch region
37 and can extend into one or both of the front waist region 36
and the back waist region 38. For example, in the exemplary chassis
100 shown in FIG. 8, an elastic strand 167a is attached adjacent
to the proximal edge 157a of the left side flap 147a and extends
into both the front waist region 36 and the back waist region 38.
Similarly, an elastic strand 167b is attached adjacent to the proximal
edge 157b of the right side flap 147b and extends into both the
front waist region 36 and the back waist region 38.
[0130] Each flap elastic member can be enclosed inside a folded
hem. For example, in the exemplary chassis 100 shown in FIGS. 11
and 12, the elastic strand 167a is enclosed inside a hem 170a formed
adjacent to the proximal edge 157a of the left side flap 147a and
the elastic strand 167b is enclosed inside a hem 170b formed adjacent
to the proximal edge 157b of the right side flap 147b. Alternatively,
the flap elastic member can be sandwiched between two layers of
the chassis, e.g., between the layers of a laminate backsheet or
between a backsheet and an inner liner. As another alternative,
the flap elastic member can be attached on a surface of the chassis
100 and remain exposed.
[0131] When stretched, the flap elastic member disposed adjacent
each side flap edge allows the side flap edge to extend to the flat
uncontracted length of the chassis 100 as shown in FIG. 8. When
allowed to relax, the flap elastic member contracts to gather the
portion of the side flap edge along which the flap elastic member
is attached and thereby make the relaxed length of the side flap
edge less than the flat uncontracted length of the chassis. For
example, when the exemplary garment 20 is in a relaxed condition
as shown in FIG. 21, the elastic strand 167a contracts to gather
the proximal edge 157a of the left side flap 147a and the elastic
strand 167b contracts to gather the proximal edge 157b of the right
side flap 147b. The contractive forces of the elastic strands 167a
and 167b are transmitted at the respective front attachment zones
151a and 151b to the interior surface 102 of the chassis 100 at
the front waist region 36. Similarly, the contractive forces of
the elastic strands 167a and 167b are transmitted at the respective
back attachment zones 152a and 152b to the interior surface 102
of the chassis 100 at the back waist region 38. These contractive
forces pull the front waist region 36 and the back waist region
38 toward each other and thereby bend the garment 20 into a "U"
shape in which the interior of the "U" shape is formed
by the portions of the garment 20 that are intended to be placed
toward the body of the wearer. Because the proximal edge 157a remains
free between the attachment zones 151a and 152a, the contractive
force of the elastic strand 167a lifts the proximal edge 157a away
from the interior surface 102 of the chassis 100. Similarly, because
the proximal edge 157b remains free between the attachment zones
151b and 152b, the contractive force of the elastic strand 167b
lifts the proximal edge 157b away from the interior surface 102
of the chassis 100. As shown in FIG. 21, this lifting of the proximal
edges 157a and 157b when the garment 20 is in the relaxed condition
lifts the side flaps 147a and 147b into position to serve as side
barriers adjacent to the side edges 237a and 237b of the absorbent
assembly 200.
[0132] When the garment 20 is worn, the relaxed "U" shape
generally conforms to the body of the wearer such that the front
waist region 36 and the back waist region 38 encircle the waist
and the legs of the wearer. When the pull-on garment 20 is worn
in this manner, the elastic strands 167a and 167b tend to hold the
lifted proximal edges 157a and 157b of the side flaps 147a and 147b
in contact with the body of the wearer and thereby form seals to
help prevent the leakage of deposited bodily waste out of the pull-on
garment 20. The lateral spacing of the lifted proximal edges 157a
and 157b is selected to allow the deposit of bodily wastes from
the lower torso of the wearer into the space between the lifted
side flaps 147a and 147b and thereby directly onto the absorbent
assembly 200. The width of each of the side flaps 147a and 147b
in effect becomes its height when the free portion of its proximal
edge 157a and 157b, respectively, is lifted and the side flap serves
as a side barrier to leakage. This height preferably is selected
to allow the lifted proximal edges 157a and 157b to fit into the
leg creases of the body of the wearer at the same time as the absorbent
assembly 200 is held in contact with the body.
[0133] As illustrated in FIGS. 8-9, the chassis 100 can have a
generally rectangular shape, which may be desirable in order to
minimize the amount of waste material and the difficulty associated
with the manufacture of the pull-on garment 20. Alternatively, the
chassis side edges 137a and 137b may not be straight, but instead
can be curved and/or notched, thereby giving an overall shape in
plan view of an hourglass or of an "I" to the pull-on
garment 20. Such a non-rectangular configuration may be desirable
in order to impart a tailored appearance to the pull-on garment
20 when it is worn, and further to impart an impression that the
pull-on garment 20 will fit comfortably between the legs of a wearer.
Any one of many well-known techniques can be used to form a non-rectangular
configuration of the chassis. For example, the chassis 100 can be
made narrower in the crotch region 37 than at the waist edges 136
and 138 by removing laterally distal portions from the chassis 100
to make its lateral dimension at and adjacent to the lateral chassis
axis 44 smaller than its lateral dimension at and adjacent to the
front waist edge 136 and smaller than its lateral dimension at and
adjacent to the back waist edge 138. Alternatively, a portion of
each of the side edges 137a and 137b can be folded laterally inward
in order to achieve the same result. Such folded portions of the
side edges 137a and 137b can be creased or attached, or both creased
and attached, in order to prevent their unfoldment.
[0134] Part or all of the chassis 100 can be made extensible to
a degree greater than the inherent extensibility of the material
or materials from which the chassis is made (e.g., the backsheet
26, the inner liner 22, or both). Advantageously, the extensible
chassis 100 can exhibit an elastic-like behavior in the direction
of elongation without the use of added elastic materials. The elastic-like
behavior can be modified and/or provided as desired in a web material
325 (FIG. 22) as described below. The additional extensibility may
be desirable in order to allow the chassis 100 to conform to the
body of a wearer during movement by the wearer. The additional extensibility
may also be desirable, for example, to allow the user of a pull-on
garment 20 including a chassis 100 having a particular size before
extension to extend the front and/or back waist regions 36 and 38
to enable the pull-on garment to be pulled over the hips of the
wearer and then to contract to encircle the waist of an individual
wearer whose waist circumference is typically smaller than the circumference
as measured at the hips of the wearer. Such extension of the waist
region(s) can give the pull-on garment 20 a generally hourglass
shape, so long as the crotch region 37 is extended to a relatively
lesser degree than the waist region(s), and can impart a tailored
appearance to the pull-on garment 20 when it is worn. In addition,
the additional extensibility may be desirable in order to minimize
the cost of the pull-on garment 20. Specifically, a lesser amount
of material is needed in order to make a diaper capable of being
properly fit onto a given size of a wearer when the material is
made extensible as described.
[0135] Additional extensibility in the chassis 100 in the lateral
direction is relatively more useful than additional extensibility
in the longitudinal direction. The abdomen of the wearer is likely
to expand when the wearer changes posture from standing to sitting
and the corresponding abdominal expansion increases the circumference
that is encircled by the waist edges of the chassis 100, rendering
lateral extension of the waist region or regions particularly advantageous.
[0136] Additional lateral extensibility in the chassis 100 can
be provided in a variety of ways. For example, a material or materials
from which the chassis 100 is made can be pleated by any of many
known methods. Alternatively, all or a portion of the chassis 100
can be made of a formed elastic-like web material or a formed laminate
of web materials like those described in U.S. Pat. No. 5,518,801
(issued May 21, 1996 to Chappell et al), U.S. Pat. No. 5,691,035
(issued Nov. 25, 1997 to Chappell et al), U.S. Pat. No. 5,723,087
(issued Mar. 3, 1998 to Chappell et al), U.S. Pat. No. 5,891,544
(issued Apr. 6, 1999 to Chappell et al), and U.S. Pat. No. 5,968,029
(issued Jan. 19, 1999 to Chappell et al). An exemplary fragment
320 of such a formed web material 325 is shown in FIG. 22. This
formed web material 325 includes distinct laterally extending regions
310 in which the original material has been altered by embossing
or another method of deformation to create a pattern of generally
longitudinally oriented alternating ridges 312 and valleys 314.
The formed web material 325 also includes laterally extending unaltered
regions 316 located between the laterally extending altered regions
310.
[0137] Such a formed web material 325 can be laterally extended
beyond its original dimension with the application of relatively
less force than that required to extend the same material to the
same extent when undeformed. In particular, the effects of an application
of opposing divergent forces directed generally perpendicular to
the ridges 312 and valleys 314 include an extension of such a formed
web material along an axis between the opposing forces and the generation
of a resistive contractive force, primarily in the unaltered regions
316. This resistive force is relatively smaller than the resistive
force that is generated by the same material in its unaltered form
when extended to the same extent, at least up to an extension at
which the ridges and valleys in the altered regions flatten and
begin to contribute to the resistive force. Thus, such formed web
materials exhibit an extensible behavior resembling that of traditional
elastic materials in the range of extensibility that is useful for
the type of lateral extension desired for use in absorbent articles.
However, such formed web materials can be made of relatively less
expensive materials that are not inherently elastic and, thus, their
use can provide an advantage in terms of the cost of manufacturing
the absorbent articles.
[0138] The range of extensibility of a web material or a laminate
that is formed as described in the Chappell et al. '801 patent can
be controlled by the degree of deformation of the altered regions
and can be varied from near zero to a maximum that is dependent
upon the original material. For example, the materials used in the
chassis 100 (e.g., the backsheet 26) of the exemplary pull-on garment
20 can typically be formed to provide any range of extensibility
from a minimum of 20% to a maximum of more than 100 percent of the
original dimension. In some embodiments of the present invention,
a portion of the chassis 100 can have a level of extensibility within
a range whose lower end is defined by and between 20%, 25%, and
30%, and whose upper end is defined by and between 40%, 60%, and
80%. The requisite levels of extensibility are achieved by application
of an opposing divergent force in the direction of extensibility
of preferably less than 1,000 grams/inch, more preferably less than
700 grams/inch. However, it should be easily appreciated that any
particular value for the maximum extensibility in the range from
approximately twenty percent to approximately 100 percent can be
selected to suit a particular choice of the original size of the
garment 20 and the range of sizes of the intended wearers. In particular,
a diaper having a specific unextended waist opening circumference
can be suitable for use on wearers having waist circumferences ranging
from equal to this unextended waist opening circumference up to
the maximum extensibility.
[0139] When the web 325 is subjected to an applied elongation,
the web material exhibits an elastic-like behavior as it extends
in the direction of applied elongation and returns to its substantially
untensioned condition once the applied elongation is removed, unless
the web material is extended beyond the point of yielding. The web
extensibility is adjustable by varying the percentage of the web
surface which is comprised of the ridges 312 and valleys 314. This
can be achieved, for instance, by modifying the widths of the ridges
312 and valleys 314, and the spacing between adjacent ridges 312
and valleys 314. A higher percentage of area coverage of the web
material 325 by the ridges 312 and valleys will increase the overall
extensibility of the web 325. The web 325 is able to undergo multiple
cycles of applied elongation up to the yield point without losing
its ability to substantially recover. Accordingly, the web 325 is
able to return to its substantially untensioned condition once the
applied elongation is removed (e.g., as the chassis 100 is pulled
over the wearer's waist region during use).
[0140] The front laterally central portion 117 and the back laterally
central portion 118 of the chassis 100 between the attachment zones
151-154 where the side flaps 147a and 147b are attached to the interior
surface 102 of the chassis 100 adjacent to the respective waist
edges 137 and 138 can have a different range of extensibility from
the portions of the chassis 100 in the attachment zones. Additionally
or alternatively, the laterally central portions 117 and 118 can
be extensible to a greater or lesser degree when subjected to a
given level of opposing tensile forces, and can thus be more easily
or less easily extensible than the portions of the chassis in the
attachment zones 151-154. For example, if the chassis 100 is made
uniformly extensible across its entire width prior to the formation
of the side flaps 147a and 147b, the double layering in the areas
of the attachment zones after the formation of the side flaps can
have an effect of decreasing the degree of lateral extensibility
of those areas under a given level of opposing tensile forces, such
as by the side flaps acting as parallel "springs" that
must be extended in order to extend the underlying attached portion
of the chassis. As another example, the altered regions in the laterally
central portions of the chassis can be deformed to a greater or
a lesser degree than the altered regions in the attachment zones
to render the laterally central portions more easily or less easily
extensible than the respective portions in the attachment zones.
Such differential range of extensibility and/or differential relationship
of tensile force to extensibility may be desirable. For example,
when the waist regions are laterally extended by a user when applying
a pull-on garment to the body of a wearer, each waist region is
typically subjected to a generally uniform level of opposing tensile
forces across its entire width, so long as the user grasps the garment
20 at or adjacent to the laterally opposing side edges 137a and
137b. If the laterally central portion of the chassis is less easily
extensible than the portions in the attachment zones, the lateral
spacing between the proximal edges 157a and 157b of the side flaps
147a and 147b will increase less under a given level of applied
tensile forces than if the laterally central portion were equally
easily extensible or more easily extensible than the portions in
the attachment zones 143a-b and 150a-b. This effect of minimizing
the change in the lateral spacing between the side flaps 147a and
147b can help to ensure that the pull-on garment 20 fits as intended
on the body of the wearer by, for example, making it more likely
that the proximal edges 157a and 157b of the side flaps 147a and
147b will fit into the leg creases of the body while the pull-on
garment 20 is being worn.
[0141] Any of a variety of extensible materials can be formed as
described in the Chappell et al. '801 patent. For example, a film,
a nonwoven, or a laminate of either or both of these materials can
be formed to provide the desired extensibility. It is also possible
to modify such a material in more than one way while forming it
to provide extensibility. For instance, a film that is originally
formed to resist the permeation of vapor through its thickness and
to contain fine particles of a granular filler material such as
calcium carbonate can be treated as described in the Chappell et
al. '801 patent to simultaneously provide extensibility and create
small holes that allow water vapor to pass through its thickness.
Thus, the film can simultaneously be rendered extensible and breathable.
Alternatively, a portion of the backsheet 26 can be ring-rolled
and thus rendered highly extensible as described in U.S. Pat. No.
5,366,782 (issued Nov. 22, 1994 to Curro, et al). Specifically,
a ring-rolling apparatus includes opposing rolls having intermeshing
teeth that incrementally stretch and thereby plastically deform
the material forming backsheet 26 (or a portion thereof) thereby
rendering the backsheet 26 extensible in the ring-rolled regions.
In one embodiment, the backsheet 26 can be ring-rolled in a portion
of at least one of the front or back waist regions while other regions
may comprise a structured elastic-like formed web material. The
chassis may be ring-rolled across the entire width in one or both
of the waist regions or alternatively may be ring-rolled over only
a portion of the chassis width. In yet another embodiment the chassis
may be ring-rolled in the portion of the chassis 100 wherein the
side flaps 147 overlap and are joined to the chassis 100 in attachment
zones 151, 152, 153, and 154.
[0142] Furthermore, once the garment 20 has been positioned on
the lower torso region of the wearer, the web 325 enables the garment
20 to apply a contractive force at the front and back waist regions
36 and 38, respectively, to the wearer's body at a level greater
than 100 grams, alternatively greater than 200 grams, and alternatively
still greater than 300 grams. It may also be desired that the chassis
applies a contractive force at the waist regions 36 and 38 that
is less than 2,000 grams, alternatively less than 1,500 grams and
alternatively still less than 1,000 grams. As described in the Chappell
et al. '801 patent, the resistive force exerted by the web 325 (i.e.,
the contractive force) in response to an applied elongation can
be modified. Specifically, the web can be designed to yield virtually
any resistive force which is less than that of the base web material
by adjusting the percentage of the web surface which is comprised
of the first and second regions. With respect to the web material,
if the material has a higher percentage of area coverage comprising
ridges 312 and valleys 314, the resultant resistive force of the
exerted by the against an applied elongation for a given material
composition and cross-sectional area will be decreased.
[0143] Extension versus force and contractive force can be determined
by ASTM 882-02 with the following modifications. A sample representative
of the extensible material disposed in the waist region should be
collected for the test. In the test a 5.08 cm by 15.24 cm (2 inch
by 6 inch) sample is cut from the material such that the edges are
straight. The sample is clamped into the tensile tester. The clamps
are attached 10.16 cm (4 in) from each other on the sample. The
sample is pulled steadily at a speed of 2.54 cm/min (1 in/min) to
20% extension and then immediately returned to 0% (4 in. spacing
between the clamps) at the same steady speed. Data, extension in
mm and force in grams, should be collected at a rate of at least
1 data point per second. The data can be graphed to provide a curve
of % extension versus force such that the extension at various tensile/contractive
forces can be determined. The extension force can be determined
by the extension curve and the contractive force can be determined
by the return curve. This test should be repeated at 30, 40, 50,
60, 70, 80, 90 and 100% extension using a new specimen for each
test. A representative sampling should be made for each condition.
[0144] To compare the extension force and contractive force of
one pull-on garment to another, the diaper in question is applied
to a representative group of wearers within the specified size range
of the diaper and the circumferential waist dimension of the diaper
and/or wearer is determined. The circumferential |