U.S. patent application number 14/542714 was filed with the patent office on 2015-04-02 for absorbent article.
The applicant listed for this patent is The Procter & Gamble Company. Invention is credited to Steven Stuart Bullock, Yukio Heki, Niels Hollenberg, Toshiyuki Iwata, Masahiro Kondo, John Peter Lankhof.
Application Number | 20150094677 14/542714 |
Document ID | / |
Family ID | 37495770 |
Filed Date | 2015-04-02 |
United States Patent
Application |
20150094677 |
Kind Code |
A1 |
Lankhof; John Peter ; et
al. |
April 2, 2015 |
ABSORBENT ARTICLE
Abstract
An absorbent article for wearing about the lower torso of a
wearer includes a topsheet, a backsheet joined to at least a
portion of the topsheet, and an absorbent core disposed between the
topsheet and the backsheet. The absorbent core includes a first
layer and a second layer, wherein the first layer is disposed in
fluid communication with the second layer. The first layer has a
first shape and the second layer has a second shape. The first
shape is different from the second shape. Each of the first layer
and second layer comprise less than about 20 percent airfelt.
Inventors: |
Lankhof; John Peter;
(Schmitten, DE) ; Heki; Yukio; (Kobe, JP) ;
Kondo; Masahiro; (Kobe-shi, JP) ; Hollenberg;
Niels; (Schwalbach am Taunus, DE) ; Bullock; Steven
Stuart; (Loveland, OH) ; Iwata; Toshiyuki;
(Kobe, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Procter & Gamble Company |
Cincinnati |
OH |
US |
|
|
Family ID: |
37495770 |
Appl. No.: |
14/542714 |
Filed: |
November 17, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11506387 |
Aug 18, 2006 |
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14542714 |
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60818109 |
Jun 30, 2006 |
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60710032 |
Aug 19, 2005 |
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Current U.S.
Class: |
604/366 |
Current CPC
Class: |
A61F 13/4704 20130101;
A61F 2013/51026 20130101; A61F 13/5611 20130101; A61F 13/531
20130101; A61F 13/84 20130101; A61F 13/535 20130101; A61F 13/53756
20130101; A61L 15/28 20130101; A61F 13/51394 20130101; A61F
13/53713 20130101; A61F 2013/5315 20130101; A61F 2013/1539
20130101 |
Class at
Publication: |
604/366 |
International
Class: |
A61F 13/531 20060101
A61F013/531; A61F 13/535 20060101 A61F013/535 |
Claims
1. An absorbent article, comprising: a. a topsheet comprising
indicia that is disposed on a lower surface of the topsheet and
that is visible through the topsheet; b. a backsheet comprising
adhesive on an exterior surface thereof; c. an absorbent core
disposed between the topsheet and the backsheet; d. a storage layer
disposed between the absorbent core and the backsheet; and e. a
layer of material that is different from and disposed between the
absorbent core and the storage layer; f. wherein the absorbent core
comprises an absorbent foam; and g. wherein the storage layer
comprises a mixture of fibers and particulate absorbent gel
material.
2. The absorbent article of claim 1, wherein the article has a
shape that is asymmetric about its lateral axis.
3. The absorbent article of claim 2, wherein the absorbent core has
a shape that is asymmetric about its lateral axis.
4. The absorbent article of claim 1, wherein the absorbent core has
a shape that is asymmetric about its lateral axis.
5. The absorbent article of claim 1, wherein the topsheet comprises
a nonwoven material.
6. The absorbent article of claim 5, wherein the nonwoven material
comprises polypropylene fibers.
7. The absorbent article of claim 1, wherein a violet, blue, or
lavender color is added to at least one of the topsheet and the
absorbent core.
8. An absorbent article, comprising: a. a topsheet; b. a backsheet
comprising adhesive on an exterior surface thereof; c. an absorbent
core disposed between the topsheet and the backsheet, wherein the
absorbent core comprises a first layer and a second layer, and
wherein the first layer has a shape that is different from that of
the second layer; d. first indicia that is disposed on a lower
surface of the topsheet and that is visible through the topsheet;
and e. second indicia that is disposed on a body-facing portion of
a layer situated below the topsheet and that is visible through the
topsheet.
9. The absorbent article of claim 8, wherein the article has a
shape that is asymmetric about its lateral axis.
10. The absorbent article of claim 9, wherein the absorbent core
has a shape that is asymmetric about its lateral axis.
11. The absorbent article of claim 8, wherein the absorbent core
has a shape that is asymmetric about its lateral axis.
12. The absorbent article of claim 8, wherein the second indicia
comprises speckles or dots.
13. The absorbent article of claim 8, wherein the first indicia
and/or the second indicia comprises a color selected from the group
consisting of violet, blue, lavender, and combinations thereof.
14. An absorbent article, comprising: a. a topsheet; b. a backsheet
comprising adhesive on an exterior surface thereof; c. an absorbent
core disposed between the topsheet and the backsheet; d. a storage
layer disposed between the absorbent core and the backsheet; and e.
an acquisition layer disposed between the absorbent core and the
storage layer; f. wherein the absorbent core and the storage layer
are different shapes; g. wherein the absorbent core comprises an
upper acquisition layer that is adjacent to the topsheet and that
comprises a nonwoven; h. wherein the absorbent core comprises a
lower acquisition layer that comprises pulp fibers; and i. wherein
the storage layer comprises absorbent gel material.
15. The absorbent article of claim 14, wherein the article has a
shape that is asymmetric about its lateral axis.
16. The absorbent article of claim 14, further comprising a first
indicia disposed on a lower surface of the topsheet and that is
visible through the topsheet; and a second indicia that is disposed
on a body-facing portion of the absorbent core and/or the storage
layer and that is visible through the topsheet.
17. An absorbent article, comprising: a. a topsheet; b. a backsheet
comprising adhesive on an exterior surface thereof; c. an absorbent
core disposed between the topsheet and the backsheet; d. a storage
layer disposed between the absorbent core and the backsheet; e. an
acquisition layer disposed between the absorbent core and the
topsheet; and f. a pair of elasticized cuffs; g. wherein the
absorbent core and the storage layer are different shapes; and h.
wherein the absorbent article and/or the absorbent core has a shape
that is asymmetrical about its lateral axis.
18. The absorbent article of claim 17, wherein both the absorbent
article and the absorbent core have a shape that is asymmetrical
about their respective lateral axis.
19. The absorbent article of claim 17, further comprising indicia
disposed on a lower surface of the topsheet, wherein the indicia is
visible through the topsheet.
20. The absorbent article of claim 19, wherein the indicia
comprises speckles or dots.
21. The absorbent article of claim 19, wherein the indicia
comprises a color selected from the group consisting of violet,
blue, lavender, and combinations thereof.
Description
FIELD OF INVENTION
[0001] The present application relates generally to absorbent
articles and more particularly to a disposable absorbent article,
such as an adult incontinence pad.
BACKGROUND
[0002] Infants, children and adult incontinent individuals wear
disposable personal care absorbent articles such as diapers,
training pants, and incontinent briefs, to receive and contain
discharged urine and excrement. Disposable personal care absorbent
articles such as diapers, training pants, and incontinent briefs,
are well known in the art. These disposable personal care absorbent
articles can function both to retain the discharged materials and
to isolate those materials from the body of the wearer as well as
from the garments, clothing and bedding, of the wearer. Generally,
such disposable personal care absorbent articles collect and retain
urine and excrement including fecal material and any other waste
matter discharged from the alimentary canal and deposited thereon
by the wearer.
[0003] Typical incontinence pads are attached to an inner surface
of a garment and fit between legs of a user. Incontinence pads
often include a topsheet which faces towards and contacts the body
of the wearer and a liquid impervious backsheet that is positioned
opposite the topsheet. Between the topsheet and the backsheet is an
absorbent core. A typical absorbent core includes a relatively
thick absorbent structure of a combination of fibrous material such
as comminuted wood pulp allowing the topsheet to be drained of
liquid that contacts it so that the topsheet may acquire and
distribute more liquids. The absorbent core absorbs urine or other
liquids and transfers these liquids to a storage area keeping the
wearer dry even when the disposable diaper or incontinence pad is
removed from the wearer.
[0004] Typically, to increase capacity of the absorbent core, the
dry volume of the absorbent structure of the absorbent core is
increased. A caliper of an absorbent structure may be up to 80
percent of a total dry caliper of the incontinence pad.
[0005] It is often desirable to provide incontinence pads having
increased capacity to absorb and retain urine and other bodily
exudates. In order to increase capacity of the incontinence pads,
the dry volume including the thickness of the absorbent core is
typically increased. Such an increase in thickness can result in a
decrease in a wearer's comfort, thereby inducing the wearer to
select a pad that may not possess the absorbency necessary to meet
the wearer's needs.
SUMMARY
[0006] One embodiment of the present invention features an
absorbent article that includes a topsheet, a backsheet joined at
least to a portion of the topsheet, and an absorbent core located
between the topsheet and the backsheet. The absorbent core
comprises a first storage layer and a second storage layer, wherein
the first storage layer is in fluid communication with the second
storage layer. The first storage layer has a first shape and the
second storage layer has a second shape. The first shape is
different from the second shape. Additionally, each of the first
storage layer and second storage layer comprise less than about 20
percent airfelt.
[0007] The details of one or more embodiments of the invention are
set forth in the accompanying drawings and the description below.
Other features, objects and advantages of the invention will be
apparent from the description and drawings, and from the
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a top plan view of an embodiment of an
incontinence pad with the body-facing surface of the pad facing the
viewer.
[0009] FIG. 2 is a top plan view of the incontinence pad of FIG. 1
affixed to an undergarment with the body-facing surface of the pad
facing the viewer.
[0010] FIG. 3 is a diagrammatic illustration of an embodiment of an
incontinence pad product.
[0011] FIG. 4 is a back view of the incontinence pad of FIG. 1.
[0012] FIG. 5A is a section view of the incontinence pad of FIG. 1
taken along line 5A-5A of FIG. 1.
[0013] FIG. 5B is a section view of the incontinence pad similar to
FIG. 5A but showing the pad in an expanded state.
[0014] FIG. 6A is a section view of another embodiment of an
incontinence pad constructed in accordance with the present
invention.
[0015] FIG. 6B is a section view showing the incontinence pad of
FIG. 6A in an expanded state.
[0016] FIG. 7 is a section view of another embodiment of an
incontinence pad.
[0017] FIG. 8 is a section view of the incontinence pad of FIG. 7
in an expanded state.
[0018] FIG. 9 is a section view of another embodiment of an
incontinence pad.
[0019] FIG. 10 is a section view of another embodiment of an
incontinence pad.
[0020] FIG. 11A is a section view of another embodiment of an
incontinence pad.
[0021] FIG. 11B is a section view of another embodiment of an
incontinence pad.
[0022] FIG. 12A is a section view of another embodiment of an
incontinence pad.
[0023] FIG. 12B is a section view of another embodiment of an
incontinence pad.
[0024] FIG. 12C is a plan view of the incontinence pad of FIG.
12A.
[0025] FIG. 13 is a section view of an embodiment of a storage
layer.
[0026] FIG. 14 is a section view of another embodiment of a storage
layer.
[0027] FIG. 15A is a perspective view of the storage layer of FIG.
13.
[0028] FIG. 15B is a plan view of the storage layer of FIG.
15A.
[0029] FIG. 16 is a diagrammatic view of an embodiment of a testing
apparatus.
[0030] FIG. 17 is a top plan view of an absorbent core of the
incontinence pad of FIG. 1.
[0031] FIG. 18 is a top plan view of an embodiment of an
incontinence pad including indicia with the body-facing surface of
the pad facing the viewer.
[0032] FIG. 19 is a top plan view of another embodiment of an
incontinence pad including indicia with the body-facing surface of
the pad facing the viewer.
[0033] FIG. 20 a top plan view of another embodiment of an
incontinence pad including indicia with the body-facing surface of
the pad facing the viewer.
[0034] FIG. 21 is a top plan view of the incontinence pad of FIG. 1
in a folded configuration.
[0035] FIG. 22 is a section view along line 22-22 of FIG. 21.
[0036] FIG. 23 is a section view of an embodiment of a wrapping
sheet at area 21 of FIG. 22.
[0037] FIG. 24 is a section view of another embodiment of a
wrapping sheet.
[0038] FIG. 25A is a section view of another embodiment of an
incontinence pad including a reinforcement element.
[0039] FIG. 25B is a plan view showing the garment-facing surface
of an incontinence pad constructed in accordance with the present
invention.
[0040] FIGS. 26-31B illustrate a method and apparatus for testing
peel strength.
[0041] FIG. 32 illustrates a method and apparatus for testing wet
immobilization.
[0042] FIG. 33 is a plan view of another embodiment of an
incontinence pad.
[0043] FIG. 34 is a plan view of another embodiment of an
incontinence pad.
DETAILED DESCRIPTION
[0044] As used herein, the term "absorbent article" refers to
devices which absorb and contain body exudates (e.g., urine and
excrement), and more specifically, refers to devices which are
placed against or in proximity to the body of the wearer to absorb
and contain the various exudates discharged from the body.
[0045] The terms "absorbent pad" and "incontinence pad" refer to an
absorbent article generally sized and shaped to fit in the crotch
region of a wearer and generally configured to be worn with an
undergarment, such as underwear.
[0046] As used herein, the term "disposable" is used to describe
absorbent articles which 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).
[0047] As used herein, the term "disposed" refers to an element
being located in a particular place or position.
[0048] As used herein, the term "joined" encompasses configurations
whereby an element is directly secured to another element by
affixing the element directly to the other element, and
configurations whereby an element is indirectly secured to another
element by affixing the element to intermediate member(s) which in
turn are affixed to the other element.
[0049] The term "layer," as used herein, does not necessarily limit
an element to a single strata of material in that a layer may
actually include a carrier material and another material carried
thereon, laminates or combinations of sheets or webs, e.g., of the
same or of differing materials.
[0050] A "unitary" absorbent article refers to absorbent articles
which are formed of separate parts united together to form a
coordinated entity so that they do not require separate
manipulative parts like a separate holder and liner.
[0051] The term "longitudinal" refers to a direction running
generally parallel to the maximum linear dimension of an element.
Directions within .+-.45 degrees of the longitudinal direction are
considered to be "longitudinal."
[0052] The term "lateral" refers to a direction running generally
at a right angle to the longitudinal direction. Directions within
.+-.45 degrees of the lateral direction are considered to be
"lateral."
[0053] For purposes of describing an embodiment of the invention,
the description below will focus on adult incontinence pad
examples. However, these embodiments are exemplary as aspects may
apply to other absorbent articles, such as incontinence briefs,
diapers, incontinence undergarments, absorbent inserts, absorbent
liners, sanitary napkins, and the like. U.S Provisional Application
Ser. No. 60/710,032 filed on Aug. 19, 2005 and U.S. Provisional
Application Ser. No. 60/818,109 filed on Jun. 30, 2006, describe
disposable absorbent articles which are constructed in accordance
with the present invention.
[0054] A. Incontinence Pad
[0055] Referring to FIG. 1, an adult incontinence pad 10 is shown
in a flat, laid-out state with a body-facing portion 12 of the
incontinence pad 10 oriented towards the viewer. The incontinence
pad 10 may include a chassis 14 with a liquid permeable topsheet 16
and a liquid impermeable backsheet 18 joined to the topsheet 16 to
form a core receiving volume 20 located therebetween. An absorbent
core 22 can be disposed in the core receiving volume 20, between
the topsheet 16 and the backsheet 18. As shown, in some
embodiments, the absorbent core 22 may include a storage layer 24
having opposite side edges 26 and 28 (shown only in part by the
dotted lines) and an acquisition system 30 located between the
storage layer 24 and the topsheet 16.
[0056] Incontinence pad 10 may further include a first elasticized
leg cuff 32 extending longitudinally along a length of the
body-facing portion 12 and a second elasticized leg cuff 34
extending longitudinally along a length of the body-facing portion
12 aligned with (e.g., substantially parallel to) the elasticized
leg cuff 32. As used herein, the term "longitudinal" refers to a
direction substantially parallel to a longitudinal axis 54 of the
incontinence pad 10.
[0057] Each elasticized leg cuff 32, 34 include a respective
standing line 23. Standing lines 23 include a first portion 25 that
is bonded to the topsheet 16 at a first end of the elasticized leg
cuffs 32, 34, a second portion 27 that is bonded to the topsheet 16
at a second, opposite end of the leg cuffs 32, 34 and a free
portion 29 unbonded to the topsheet 16 between the first and second
portions 25 and 27. In some embodiments, standing lines 23 can be
about 15 mm or less from a closest longitudinal edge of the
acquisition system 30.
[0058] B. Incontinence Pad Shape and Sizing
[0059] Incontinence pad 10 is shown to have a back region 36, a
front region 38 opposite the back region 36, a crotch region 40
between the back region 36 and the front region 38, and a periphery
42, which, in the illustrated example, is formed by an outer
perimeter of backsheet 18 which includes end edges 44 and 46 and
side edges 48 and 50. Back region 36 extends from end edge 44 to
the crotch region 40 and front region 38 extends from end edge 46
to crotch region 40. The terms front and back regions are used
merely to differentiate between pad regions and not to denote a
preferred pad position during use.
[0060] Body-facing portion 12 includes that portion of the
incontinence pad 10 which is positioned adjacent to a wearer's body
during use. A garment-facing portion 52 of the incontinence pad 10
includes that portion of the incontinence pad 10 which is
positioned adjacent a garment of the wearer during use.
Garment-facing portion 52 is generally formed by at least a portion
of the backsheet 18 and, in some embodiments, by other components
joined to the backsheet 18.
[0061] Incontinence pad 10 has a pair of axes, the longitudinal
axis 54 and a lateral axis 56 that extends substantially transverse
to the longitudinal axis. Each axis 54, 56 passes through a point P
located at the geometric center of the incontinence pad 10. In the
illustrated embodiment, longitudinal axis 54 intersects each of the
end edges 44 and 46 and spans a maximum length L of the
incontinence pad 10, while lateral axis 56 intersects the side
edges 48 and 50. In some embodiments, the longitudinal axis 54 may
not span the maximum length of the incontinence pad 10. In certain
instances, lateral axis 56 spans a minimum width W of the
incontinence pad 10.
[0062] Periphery 42 of the incontinence pad 10 defines a pad shape.
As shown by FIG. 1, the pad shape can be asymmetric about the
lateral axis 56 in that the pad shape is not substantially
identical on each side of the lateral axis 56. For example, as
shown, in some embodiments, area A.sub.1 of the incontinence pad 10
that includes back region 36 can be substantially greater than area
A.sub.2 that includes front region 38. In some embodiments, A.sub.1
may be about five percent larger or more (e.g., about 10 percent
larger, about 15 percent larger, about 20 percent larger, etc.)
than A.sub.2.
[0063] As shown, the pad shape of the incontinence pad 10 can be
symmetric about the longitudinal axis 54 in that the pad shape is
substantially identical on each side of the longitudinal axis 54.
However, in some embodiments, the pad shape can be asymmetric about
the longitudinal axis 54 in that the pad shape is not substantially
identical on each side of the longitudinal axis 54. In some
embodiments, the pad shape may be symmetric about the lateral axis
56 in that the pad shape is substantially identical on each side of
the lateral axis 56.
[0064] Incontinence pad 10 can be sized and designed for improved
wearer comfort while providing desired properties, such as capacity
and acquisition properties. As will be described below,
incontinence pad 10 can provide improved wearer comfort while
providing desired properties, such as capacity (e.g., about 5 ml or
greater, about 200 ml or greater) and acquisition properties (e.g.,
about 1.5 g of 0.9 percent NaCl solution per second or greater
under a pressure of about 0.3 psi) through use of, in some
embodiments, superabsorbent material (which can, for instance,
comprise a particulate absorbent gel material or an AGM present in
any shape, including particles, fibers, spheres, foamed sheets,
flakes, rods, and the like) in the absorbent core 22, which can
also allow a caliper (i.e., a measured thickness) of the
incontinence pad 10 to be thin (e.g., about 20 mm or less).
[0065] In some embodiments, incontinence pad 10 can have a maximum
length L (e.g., about 260 mm, about 284 mm, about 304 mm, about 324
mm), and/or a minimum width W (e.g., about 85 mm, about 100 mm)
and/or a maximum width W' (e.g., about 130 mm, about 140 mm)
Additionally, in some embodiments, the absorbent core 22 of the
incontinence pad 10 can have a maximum length l (e.g., about 230
mm, about 254 mm, about 274 mm, about 294 mm), a minimum width w
(e.g., about 50 mm, about 65 mm) and a maximum width w' (e.g.,
about 100 mm, about 110 mm). In some embodiments, L, W, W', l, w
and w' can be selected to correspond to small, medium, large and
full figure body types. In many implementations, L, W, W', l, w and
w' are selected to correspond to undergarment sizes, which can
provide a guide for incontinence pad selection by a wearer.
[0066] Referring now to FIG. 2, a diagrammatic illustration of an
incontinence pad 10 affixed to a female undergarment 200 (i.e., a
panty). As an illustrative example, the table below presents panty
survey data for United States briefs. This survey data can be used
to correlate the size of the incontinence pad 10 with undergarment
200 size.
TABLE-US-00001 TABLE I U.S. Panty Measurement Data Brief Minimum
Crotch Width, mm Average/St Dev 69/9 Range 48-85 Front** Crotch
Width, mm Average 175/36 Range 127-250 Back** Crotch Width, mm
Average 188/47 Range 124-320 **Front and Back dimensions measured
90 mm from minimum crotch width
[0067] Along with the above survey data, other parameters may be
considered in correlating pad size and undergarment size. For
example, it may be desirable to size the incontinence pad 10 to fit
entirely within the undergarment 200 so that no portion of the
incontinence pad projects beyond the undergarment 200 during use.
An example of such an incontinence pad 10 is shown in FIG. 2. This
sizing can include both the width of the incontinence pad 10 and
the length of the incontinence pad 10. In some instances, however,
a portion of the incontinence pad 10 may project beyond the
undergarment 200 during use. Additionally, it may be desirable to
size the incontinence pad 10 so that the leg cuffs 32 and 34 may be
positioned at opposite sides of the crotch to provide a leak
barrier along each side between chassis 14 and the wearer's
body.
[0068] The table below illustrates a correlation between panty
sizes and incontinence pad sizes. It should be noted that various
embodiments can include other size correlations.
TABLE-US-00002 TABLE II Panty Size/Incontinence Pad Correlation
Chart Panty Size .ltoreq.4/5/6 ~7/8/9 ~10/11/12 13+ Pad Size Small
Medium Large X-Large Pad Length (L) 255 mm +/- 280 mm +/- 305 mm
+/- 330 mm +/- 40 mm 40 mm 40 mm 50 mm Minimum Pad 80 mm +/- 85 mm
+/- 90 mm +/- 95 mm +/- Width (W) 20 mm 20 mm 20 mm 30 mm Maximum
Pad 120 mm +/- 130 mm +/- 140 mm +/- 150 mm +/- Width (W') 20 mm 20
mm 20 mm 30 mm Minimum Core 60 mm +/- 65 mm +/- 70 mm +/- 75 mm +/-
Width (w) 20 mm 20 mm 20 mm 30 mm Maximum Core 100 mm +/- 110 mm
+/- 120 mm +/- 130 mm +/- Width (w') 20 mm 20 mm 20 mm 30 mm Pad
caliper 6 mm +/- 6 mm +/- 6 mm +/- 6 mm +/- 3 mm 3 mm 3 mm 3 mm Pad
capacity 250 g +/- 250 g +/- 250 g +/- 250 g +/- 100 g 100 g 100 g
100 g
[0069] While the above table includes four incontinence pad sizes,
in some implementations, there may be less than (e.g., three pad
sizes) or more than four pad sizes (e.g., five pad sizes). As one
example, a small pad size may correspond to 4/5/6 panty sizes, a
medium pad size may correspond to 7/8/9 panty sizes and a large pad
size may correspond to 10 and up panty sizes. As another example, a
small pad size may correspond to 3/4/5 panty sizes, a medium pad
size may correspond to 6/7/8 panty sizes, a large pad size may
correspond to 9/10 panty sizes and a full figure pad size may
correspond to 11 and up panty sizes. Other implementations are
contemplated.
[0070] Front portion 38 of the incontinence pad 10 can be sized to
fit comfortably within a wearer's crotch, between the legs of the
wearer. A location of the maximum pad width W' at the back portion
36 of the incontinence pad 10 can be offset a distance d (e.g., 90
mm) from center point P so that the maximum pad width W' can be
located away from between a wearer's legs during use whether the
back portion 36 and corresponding larger area A.sub.1 is located at
the front of the wearer's body (e.g., during the daytime, for
example, when front leakage may be of greatest concern) or at the
rear of the wearer's body (e.g., during the nighttime, for example,
when rear leakage may be of greatest concern).
[0071] The above-described sizing information can be used to
generate indicia for a wearer to utilize in selecting an
incontinence pad 10 size. Referring to FIG. 3, an incontinence pad
product 31 includes a package 33 and multiple incontinence pads 10
(e.g., five pads, 10 pads, 15 pads, 20 pads, etc.) located therein.
Incontinence pads 10 of the product 31 may all be the same size or
may be of differing sizes, such as any of those described above.
Visibly printed on the package 33 is indicia 35 for use in
determining a desired incontinence pad size, e.g., for purchase and
use. A wearer, upon determining a garment size, can refer to the
indicia 35 to determine an incontinence pad size corresponding to
the garment size. In some embodiments, the indicia may be printed
separate from the package 33, for example, as part of a display
(not shown). Other examples are possible.
[0072] Use of superabsorbent material in the core 22 allows for a
relatively consistent pad caliper, capacity and/or acquisition
properties regardless of pad size. In accordance with certain
aspects of the invention, the core 22 is manufactured (e.g., has
length and width properties) to fit a small pad size (see Table
II). The core 22 can be stretched, if desired, when integrated into
pads of larger sizes. It should be appreciated that stretching the
core 22 may correspondingly reduce the pad thickness (or caliper).
It should be further appreciated that the core 22 need not be
stretched. Instead, because the core 22 provides suitable
absorbency across the range of pad sizes, a core sized to fit a
given pad can be attached as-is to larger pads.
[0073] Accordingly, in some embodiments, an incontinence pad 10
having a length L of about 255 mm (e.g., corresponding to a small
size pad in Table II) may have pad caliper of no more than about 50
percent (e.g., no more than about 40 percent, about 35 percent,
about 30 percent, about 25 percent, about 20 percent, about 15
percent, about 10 percent, about five percent, about three percent)
greater than an incontinence pad 10 having a length L of about 330
mm (e.g., corresponding to an extra large pad size in Table II),
while maintaining desired capacity and acquisition properties. In
some embodiments, there may be relatively little deviation in pad
caliper (e.g., no more than about 50 percent, about 40 percent,
about 35 percent, about 30 percent, about 25 percent, about 20
percent, about 15 percent, about 10 percent, about five percent,
about three percent) between any two, any three, any four, or even
all incontinence pad 10 sizes between the smallest size available
for purchase and the largest size available for purchase
illustrated in Table II. Furthermore, the caliper of the pad 10 may
have substantially no variation from one pad size to the next.
[0074] More broadly stated, as a pad size increases from a first
size to a second size having a body-facing surface area between
about 5% and about 40% greater than the body-facing surface area of
the first size, the pad thickness (or caliper) decreases by an
amount less than about 50 percent (e.g., less than about 40
percent, about 35 percent, about 30 percent, about 25 percent,
about 20 percent, about 15 percent, about 10 percent, about five
percent, about three percent). Furthermore, the caliper of the pad
10 may have substantially no variation (e.g., within one percent)
from one pad size to the next.
[0075] By providing incontinence pads 10 having relatively
consistent pad calipers amongst pad sizes while providing desirable
capacity and acquisition properties for all the pad sizes, the pad
sizing information (e.g., such as that shown by FIG. 3) can be
relied upon more for wearer selection of a comfortable incontinence
pad 10 rather than absorptive qualities of the pad. This can
diminish the inducement for a wearer to select an under-absorptive
incontinence pad for comfort or an uncomfortable, improperly sized
pad for needed increased absorbency.
[0076] C. Incontinence Pad Components
[0077] For use in affixing the incontinence pad 10 to the
undergarment 200, incontinence pad 10 may include an adhesive
region of adhesive material that is applied to backsheet 18 at the
garment-facing portion 52 (shown in FIG. 1). Referring to FIG. 4,
adhesive region 202 can be somewhat mushroom or T-shaped having a
relatively narrow, elongated portion 204 and a wider, shorter
portion 206. In some embodiments, adhesive region 202 has a length
L.sub.1 (e.g., about 201 mm), length L.sub.2 (e.g., about 40 mm),
width W.sub.1 (e.g., about 40 mm) and width W.sub.2 (e.g., about 30
mm). In some embodiments, the portion 206, being wider than portion
204, may be associated with the back portion 36 of the incontinence
pad 10 having the maximum width W'. As shown, in some embodiments,
the adhesive region 202 can be asymmetric about lateral axis 56 and
symmetric about longitudinal axis 54. In other embodiments, shape
of the adhesive region 202 may be symmetric about lateral axis 56
and/or asymmetric about longitudinal axis 54. Embodiments are
contemplated where the adhesive region 202 is asymmetric about both
the lateral axis 56 and the longitudinal axis 54. Additionally,
embodiments are contemplated where the adhesive region 202 is
symmetric about both the lateral axis 56 and the longitudinal axis
54. In some implementations, adhesive region 202 is applied to
about 20 percent or more (e.g., about 30 percent or more, e.g.,
about 35 percent or more, such as about 37 percent) of the surface
area of garment facing portion 52 of the backsheet 18.
[0078] Any suitable releasable adhesive material can be used to
form the adhesive region 202, some examples of which include, NSC
2823 commercially available from National Starch and Chemical Co.
and HL1461AZP commercially available from H.B. Fuller. In some
embodiments, adhesive region 202 can provide a peel strength of
between about 70 gf/40 mm and about 800 gf/40 mm or any individual
number within the range. In some embodiments, the adhesive region
can provide a peel strength of between about 200 gf/40 mm and about
800 gf/40 mm using the hereinafter described Peel Strength
Test.
[0079] Referring to FIG. 5A, the absorbent core 22 is disposed
between the topsheet 16 and the backsheet 18. Topsheet 16 may be
fully or partially elasticized or may be foreshortened to provide a
void space between the topsheet 16 and the absorbent core 22.
Topsheet 16 can be formed of a compliant, soft-feeling and
non-irritating material that is liquid pervious permitting liquids
(e.g., urine) to readily penetrate through the thickness of the
topsheet 16.
[0080] Any suitable topsheet may be utilized in the present
invention. For example, in a specific embodiment, a non-woven
material for forming topsheet 16 is a carded non-woven material of
polypropylene, which is commercially available from Amoco Fabrics,
under Code No. Doft P-10, 23 Stly 007. As another example, in some
embodiments, the topsheet 16 may include an odor reduction layer.
Such a topsheet 16 can be formed by a non-woven material which is
treated with, for example, metalphthalocyanine material so that it
can function as an odor reduction layer.
[0081] Backsheet 18 is generally positioned away from the wearer's
skin and can inhibit exudates absorbed and contained in the
absorbent core 22 from wetting articles which contact the
incontinence pad 10 such as undergarments. The backsheet 18 can be
impervious to liquids (e. g., urine) and can be manufactured from a
laminate of a non-woven and a thin plastic film, although other
flexible materials may be used. An example of a suitable material
for the backsheet 18 is a thermoplastic film having a thickness of
from about 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mils). Other
examples of suitable backsheet films include those manufactured by
Tredegar Industries Inc. of Terre Haute, Ind. and sold under the
trade names X15306, X10962, and X10964.
[0082] In some embodiments, suitable backsheet materials may
include breathable materials that permit vapors to escape while
still preventing exudates from passing through the backsheet 18.
Exemplary breathable materials may include materials such as woven
webs, nonwoven webs, composite materials such as film-coated
nonwoven webs, and microporous films such as manufactured by Mitsui
Toatsu Co., of Japan under the designation ESPOIR NO and by EXXON
Chemical Co., of Bay City, Tex., under the designation EXXAIRE.
Suitable breathable composite materials comprising polymer blends
are available from Clopay Corporation, Cincinnati, Ohio under the
name HYTREL blend P18-3097.
[0083] As shown in FIG. 5A, the absorbent core 22 generally is
disposed between the topsheet 16 and the backsheet 18. Absorbent
core 22 may include any absorbent material that is generally
compressible, conformable, non-irritating to the wearer's skin, and
capable of absorbing and retaining liquids such as urine and other
certain body exudates. The absorbent core 22 may include a wide
variety of liquid-absorbent materials commonly used in disposable
diapers and other absorbent articles such as comminuted wood pulp,
which is generally referred to as air felt. Examples of other
suitable absorbent materials include creped cellulose wadding, melt
blown polymers including co-form, chemically stiffened, modified or
cross-linked cellulosic fibers, tissue including tissue wraps and
tissue laminates, absorbent foams, absorbent sponges,
superabsorbent polymers, absorbent gelling materials, or any other
absorbent material or combinations of materials.
[0084] In some embodiments, the absorbent core 22 can be a
substantially airfelt free core as described in U.S. patent
application Ser. No. 10/776,851 (Becker et. al), published as U.S.
Publication No. 2004/0162536. Further examples of suitable
absorbent core constructions are described in U.S. Publication No.
2004/0167486 to Busam et al. The absorbent core of the
aforementioned publication, in one embodiment, uses no or minimal
amounts of absorbent fibrous material within the core. Generally,
the absorbent core may include no more than about 20 weight percent
of absorbent fibrous material (i.e., [weight of fibrous
material/total weight of the absorbent core].times.100).
[0085] In some embodiments, absorbent core 22 may include the
acquisition system 30 which may comprise an upper acquisition layer
60 adjacent the topsheet 16, a middle acquisition layer 62 and a
lower acquisition layer 59 above a storage layer 24. The upper
acquisition layer 60, the middle acquisition layer 62, and the
lower acquisition layer 59 can be in fluid communication with each
other. In one embodiment, the upper acquisition layer 60 includes a
non-woven and the middle acquisition layer 62 includes a mixture of
chemically stiffened, twisted and curled fibers, high surface area
fibers and thermoplastic binding fibers. In another embodiment,
acquisition layers 60 and 62 are provided from a non-woven
material, which is preferably hydrophilic and lower acquisition
layer 59 is a mixed bonded air laid non-woven material. The lower
acquisition layer 59 may or may not be in direct contact with the
storage layer 24. In some embodiments, the middle acquisition layer
62 may include chemically stiffened, twisted and curled fibers
without thermoplastic binding fibers. In some embodiments, lower
acquisition layer 59 may include treated pulp fibers.
[0086] Storage layer 24 may be wrapped by a core wrap material 61.
In the illustrated embodiment, the core wrap material 61 includes a
top layer 66 and a bottom layer 68. The top layer 66 and the bottom
layer 68 may be provided from two or more separate sheets of
materials or they may be alternatively provided from a unitary
sheet of material. Such a unitary sheet of material may be wrapped
around the storage layer 24 in any suitable manner, e.g., in a
C-fold.
[0087] The core wrap material 61, the top layer 66 and/or the
bottom layer 68 can be provided from a non-woven material. One
specific example of a non-woven material includes a spunbonded, a
melt-blown and a further spunbonded layer, i.e., an SMS material.
Permanently hydrophilic non-wovens, and in particular nonwovens
with durably hydrophilic coatings can be used. In another example,
the nonwoven material may include a spunbonded layer, two adjacent
melt-blown layers and another spunbonded layer or SMMS
structure.
[0088] Some examples of non-woven materials can be provided from
synthetic fibers, such as polyethylene (PE), polyethylene
terephthalate (PET) and polypropylene (PP). As polymers used for
non-woven production may be inherently hydrophobic, they may be
preferably coated with hydrophilic coatings. An example of a
suitable method of producing non-wovens with durably hydrophilic
coatings is via applying a hydrophilic monomer and a radical
polymerization initiator onto the non-woven, and conducting a
polymerization activated via ultraviolet (UV) light resulting in
monomer chemically bound to the surface of the non-woven. Another
example of a suitable method of producing a non-woven with durably
hydrophilic coatings is to coat the non-woven with hydrophilic
nanoparticles.
[0089] Typically, nanoparticles have a largest dimension of below
750 nm. Nanoparticles with sizes ranging form 2 to 750 nm can be
economically produced. The advantages of nanoparticles is that many
of them can be easily dispersed in water solution to enable coating
application onto the nonwoven; they typically form transparent
coatings, and the coatings applied from water solutions are
typically sufficiently durable to exposure to water.
[0090] Nanoparticles can be organic or inorganic, synthetic or
natural. Inorganic nanoparticles generally exist as oxides,
silicates, carbonates. Typical examples of suitable nanoparticles
are layered clay minerals (e.g., LAPONITE from Southern Clay
Products, Inc. (USA), and Boehmite alumina (e.g., DISPERAL P2 from
North American Sasol Inc.) Other suitable examples of nanoparticles
are described in U.S. Pat. No. 6,863,933 and U.S Pat. No.
6,645,569.
[0091] In some cases, the non-woven surface can be pre-treated with
high energy treatment (corona, plasma) prior to application of
nanoparticle coatings. High energy pre-treatment typically
temporarily increases the surface energy of a low surface energy
surface (such as PP) and thus enables better wetting of a non-woven
by the nanoparticle dispersion in water. This method is discussed
in U.S. Pat. No. 6,863,933 and U.S Pat. No. 6,645,569.
[0092] As shown in FIG. 5A, in some embodiments, barrier leg cuff
sheets 83 and 85 (e.g., formed of any suitable material such as a
woven or non-woven material) can be affixed to the top sheet 16 and
the core wrap 61 to form the barrier leg cuffs 32 and 34. A first
longitudinal edge 87 of the respective barrier leg cuff sheets 83
and 85 can be affixed to the topsheet 16 and an opposite, second
longitudinal edge 89 of the respective barrier leg cuff sheets 83
and 85 can be affixed to the top layer 66 of the core wrap 61 at a
location spaced outward from the first longitudinal edge 87. As
shown, the first and second longitudinal edges 87 and 89 can be
bonded so as to provide an expandable volume 91 capable of
expanding (or increasing) in response to expansion of the storage
layer 24 (See FIG. 5B).
[0093] As shown in FIG. 6A, a barrier leg cuff sheet 683 and a
barrier leg cuff sheet 685 can be joined to the topsheet 16 and the
backsheet 18. Embodiments are contemplated where the barrier leg
cuff sheets 683 and 685 are joined to the topsheet 16 and/or the
top layer 66 of the core wrap 61. The barrier leg cuff sheet 683
may comprise an unattached portion 690, and the leg cuff sheet 685
may comprise an unattached portion 691.
[0094] As shown, in some embodiments, the barrier leg cuff sheets
683 and/or 685 may comprise a single unitary web which is folded
upon itself to form the first layer 683A and second layer 683B
and/or the first layer 685A and the second layer 685B,
respectively. In some embodiments, the barrier leg cuff sheets 683
and/or 685 may comprise separate webs which make up the first layer
683A and the second layer 683B and the first layer 685A and the
second layer 685B, respectively.
[0095] One benefit of the dual layered barrier leg cuff sheets 683
and/or 685 is that the first layer can act as a backup to the
second layer. For example, during processing of the nonwoven,
typically, because of the random assembly of fibers into a web,
portions of the nonwoven can have poor uniformity. For example, in
the case of a single layer with poor uniformity, there may be
leakage in some areas due to the poor uniformity. In contrast, with
a dual layered cuff sheet, as discussed above, the likelihood of
poor uniformity in both layers at the same location is small. As
such, the risk of leakage through a dual layered cuff sheet is
minimized.
[0096] Another benefit of the dual layered barrier leg cuff sheets
683 and/or 685 pertains to the amount of glue proximate to the
perimeter of the pad. For example, as shown in FIG. 6B, adhesive
can be applied between the first layer 685A, second layer 685B,
and/or the backsheet 18 proximate to the end edge 632. The adhesive
can have a width 635 of about 7 mm. However, in some embodiments,
the first layer 685A, the second layer 685B and/or the backsheet 18
can be crimped together proximate to the end edge 632. By crimping
these elements together, the width of adhesive applied can be
reduced or the adhesive applied between various elements can be
reduced and/or eliminated. For example, when crimping is utilized,
the width 635 of adhesive can be less than about 7 mm. As another
example if the first layer 685A and the second layer 685 are
crimped together, then adhesive may only need to be applied to join
the backsheet 18 and the crimped barrier leg cuff material. As yet
another example, when crimping is utilized, the adhesive about the
perimeter, e.g., proximate to the end edge 632, can be eliminated.
The reduced amount of adhesive applied about the perimeter of the
pad can increase the softness of the pad thereby increasing the
comfort of the wearer.
[0097] Referring now to FIG. 7, in some embodiments, storage layer
24 (here formed of layers 24A and 24B) may be wrapped with a core
wrap 63 including top layer 65 and bottom layer 67, for example,
formed from a non-woven material such as those exemplified above
with reference to layers 66 and 68. Top layer 65 can be joined to
bottom layer 67 to define a core receiving volume 69 and an
expandable volume 71. Expandable volume 71 (shown in a contracted
state) is expandable, as needed, to accommodate expansion of the
storage layer 24 as liquid is being stored therein. As shown, in
some embodiments, the volume provided between the top and bottom
layers 65 and 67 can be relatively small with the expandable volume
71 in the contracted state and can contain the storage layer 24
relatively tightly between the top layer 65 and the bottom layer
67. In some embodiments, a nonwoven layer and/or tissue layer can
separate the layer 24A from the layer 24B.
[0098] The layers 24A and 24B of the storage layer 24 may comprise
identical materials in some embodiments. For example, the layers
24A and 24B may each comprise an AGM and may each have a basis
weight of about 320 gsm. Some suitable examples of AGM are
available from Nippon Shokubai of Tokyo, Japan under the product
codes of L600 and L595 and available from BASF under the product
code of ASAP600z. Examples of other suitable materials include
those described with regard to the absorbent core heretofore.
[0099] In contrast, in some embodiments, the layers 24A and/or 24B
may comprise varying basis weights of AGM with respect to one
another. For example, in some embodiments, the layer 24A may
comprise a higher basis weight of AGM than the layer 24B. In other
embodiments, the layer 24B may comprise a higher basis weight of
AGM than the layer 24A.
[0100] Additionally, in some embodiments, the layer 24A may
comprise a different form of AGM than the layer 24B. For example in
some embodiments, the layer 24A may comprise particles having a
spherical shape while the layer 24B comprises rod shaped particles.
Furthermore, in some embodiments, the layer 24A may comprise a
different particle size than the layer 24B. For example, layer 24A
may comprise AGM particles having an average particle size of about
50 microns while layer 24B may comprise AGM particles having an
average particle size of about 1000 microns. Particle size of AGM
particles can be measured as discussed in U.S. Pat. No.
6,096,299.
[0101] As shown in FIG. 7, in some embodiments, the layer 24A may
be disposed superjacent to the layer 24B. In contrast, as shown in
FIG. 9, in some embodiments, the layer 24B can be disposed
superjacent to the layer 24A. In some embodiments, the layer 24A
may have a substantially constant width (generally parallel to the
lateral axis 56 (shown in FIG. 1). In contrast, in some
embodiments, the layer 24B may be shaped and generally follow the
curvature of the periphery 42 (shown in FIG. 1) of the incontinence
pad 10 (shown in FIG. 1). Embodiments are contemplated where the
shape of the storage layer 24A is different from the shape of the
storage layer 24B. For example, the first storage layer may be
substantially rectangular while the second storage layer may form a
portion of the outer periphery of the incontinence pad 10. As
another example, the storage layer 24A may have a first width in
the second region, and the storage layer 24B can have a second
width in the second region. In some embodiments, the first width
can be less than the second width or vice versa.
[0102] Additionally, in some embodiments, the layer 24A may
comprise more surface area than the layer 24B. In contrast, in some
embodiments, the layer 24A may comprise a smaller surface area than
the layer 24B. Alternatively, in some embodiments, the layer 24A
may comprise about the same surface area as the layer 24B.
[0103] Additionally, embodiments are contemplated where the layer
24A and the layer 24B are profiled. For example, the layer 24A may
comprise a higher gsm of AGM in the front region 38 (shown in FIG.
1) as opposed to the back region 36 (shown in FIG. 1) or vice
versa. As another example, the layer 24A may comprise a higher gsm
in the crotch region 40 (shown in FIG. 1) than both the front
region 38 (shown in FIG. 1) and the back region 36 (shown in FIG.
1). As yet another example, the layer 24A may comprise a higher gsm
of AGM on one side of the longitudinal axis 54 than the other side.
As yet another example, the layer 24A may comprise a higher gsm of
AGM on one side of the lateral axis 56 than on the other side of
the lateral axis 56. Any suitable combination of the examples
presented above can be combined to form a profiled layer 24A.
Additionally, embodiments are contemplated where the layer 24A
and/or the layer 24B are configured as described above.
[0104] As shown in FIG. 7, expandable volume 71 may be provided
through use of a first fold structure 73 and a second fold
structure 75 formed in the top layer 65 of the core wrap 63, in
some embodiments. The first fold structure 73 and the second fold
structure 75 may extend longitudinally along a length of the
incontinence pad 10 generally parallel to one another. The first
and second fold structures 73 and 75 can be spaced-apart from each
other to allow for the expandable volume 71 to be provided
therebetween.
[0105] In the unexpanded state, in some embodiments, the folds 77
of each fold structure 73, 75 can be located between and adjacent
to an upper portion 79 and a lower portion 81 of the top layer 65.
As shown, in some embodiments, the first and second fold structures
73 and 75 can be located between the storage layer 24 and the
acquisition system 30. Additionally, the acquisition system 30 can
be located between the topsheet 16 and the top layer 65 of the core
wrap 63.
[0106] Bonds 95 may be formed (e.g., through use of adhesive)
between folds 77 of the fold structures 73 and 75 to provide
resistance to unintended expansion and unfolding of the fold
structures 73, 75. In some embodiments, other adhesive materials or
fasteners may be used to provide resistance such as adhesive tape.
Some examples of adhesives suitable for use in the fold structures
73 and 75 include product codes NW1151, HL1358LO, and D3155B, each
available from H.B. Fuller Co. of St. Paul, Minn.; and product
codes 519 and 526, each available from National Starch Co. of
Bridgewater, N.J.
[0107] FIG. 8 shows expandable volume 71 in an expanded state, for
example, due to forced expansion by the storage layers 24A and 24B,
with the outer layers removed for clarity. As can be seen, the
first and second fold structures 73 and 75 allow for expansion of
the expandable volume 71 in the z direction, which increases the
overall volume between the top layer 65 and the bottom layer 67 of
the core wrap 63.
[0108] The fold structures 73 and 75 can be sized such that the
expandable volume 71 can accommodate substantially full expansion
of the storage layer 24 with the storage layer 24 at its full fluid
carrying capacity. In some embodiments, expandable volume 71
increases a total volume formed between the top layer 65 and bottom
layer 67 by about 10 percent or more. For example, the expandable
volume 71 can increase the total volume by about 15 percent, by
about 20 percent, by about 25 percent, by about 30 percent, by
about 35 percent, by about 40 percent, by about 45 percent, or by
about 50 percent or more. Additionally, in certain implementations,
the expandable volume 71, when expanded, can increase non-woven
circumference C about the periphery of the core wrap 63 by about 10
percent or more. For example, the expandable volume 71, when
expanded, can increase the circumference C about the periphery of
the core wrap 63 by about 15 percent, by about 20 percent, by about
25 percent, by about 30 percent, by about 35 percent, by about 40
percent, by about 45 percent, or by about 50 percent or more.
[0109] Referring to FIG. 9, in some embodiments, fold structures 73
and 75 can be formed in bottom layer 67 in a fashion similar to
that described above. As shown in FIG. 10, in some embodiments,
fold structures 73 and 75 may be formed in more outer layers, such
as backsheet 18. In some embodiments (not shown), fold structures
73 and 75 may be formed in more than one layer, such as in top
layer 65 and in bottom layer 67. For example, a fold structure may
be formed in a top layer 65 while a fold structure 75 is formed in
a bottom layer 67, or vice versa. As another example, the fold
structure 73 and/or fold structure 75 may each comprise a portion
of both the top layer 65 and a portion of the bottom layer 67.
[0110] Referring to FIG. 11A, still other embodiments of the
present invention contemplate that the backsheet 18 can be
configured opposite to that illustrated in FIG. 10. For instance, a
raised middle portion 93 can extend between the opposing fold
structures 73 and 75. Accordingly, during operation, when the
storage layer 24 expands, the raised middle portion 93 can be
biased downwards while the fold structures 73 and 75 unfold to
accommodate the swelling. It should be appreciated that the fold
configuration of FIG. 11A can alternatively be achieved by the top
layer 65 and the bottom layer 67, if desired.
[0111] As stated previously and as shown in FIG. 11B, the core wrap
63 may comprise the top layer 65 and the bottom layer 67 in some
embodiments. As shown, in some embodiments, the top layer 65 and
the bottom layer 67 can be joined to one another outboard of the
storage layer 24, thereby forming fold structures 1162 and 1164.
The core wrap 63 can be joined to the backsheet 18 via adhesive
elements 1150. The adhesive elements 1150 can join the core wrap 63
and storage layer 24 to the backsheet 18 in the relative center of
the article.
[0112] As shown, the fold structure 1162 may comprise a proximal
area 1162A and a distal area 1162B. Similarly, the fold structure
1164 may comprise a proximal area 1164A and a distal area 1164B. As
shown, the distal areas 1162B and 1164B can be folded under the
bottom layer 67. In this embodiment, the distal areas 1162B and
1164B can be unbonded to either the backsheet 18 or the bottom
layer 17, thereby allowing the distal areas 1162B and 1164B to move
relative to the core wrap 63.
[0113] Upon being wetted, the storage layer 24 expands. Upon
expansion of the storage layer 24, the top layer 65 and the bottom
layer 67 can separate from each other adjacent to the proximal
areas 1162A and 1162B of the fold structures 1162 and 1164,
respectively. The separation of the top layer 65 from the bottom
layer 67 adjacent to the proximal areas 1162A and 1164A can
accommodate the expansion of the storage layer 24. Additionally,
because the distal areas 1162B and 1164B can be unbonded to the
either the backsheet 18 or the bottom layer 67, the distal areas
1162B and 1164B can be displaced from between the backsheet 18 and
the bottom layer 67 upon expansion of the storage layer 24.
[0114] The top layer 65 and the bottom layer 67 can be joined by
any suitable manner known in the art. An example of a suitable
means is the adhesive utilized for the bonds 95 discussed
heretofore.
[0115] While Z-type and C-type fold structures are shown in FIGS.
7-11B, any other suitable fold structure can be employed such as
multiple, bellow-type folds, ripples, etc., for example, having
more than two folds each. Additionally, similar fold structures 73
and 75 may be formed in any of the topsheet 16, backsheet 18, at
the leg cuffs 32, 34, as examples, to form a respective expandable
portion that can expand, for example, in response to expansion of
the absorbent core 22. Fold structures can reduce the tension in
the wrap material and reduce the propensity for tearing the wrap
material. As an alternative or in addition to fold structures
materials may be formed of a stretchy or expansive material to
allow for core expansion.
[0116] Additionally, while the barrier leg cuffs 32 and 34 of FIGS.
7-11B illustrate embodiments where the barrier leg cuff sheet
includes a single layer, embodiments are contemplated where the
barrier leg cuff sheet material comprises multiple layers as
described with regard to FIG. 6A and 6B.
[0117] As stated previously, with regard to FIG. 5A, in some
embodiments, the absorbent core 22 may comprise an acquisition
system 30 which includes a plurality of layers and the storage
layer 24. As shown in FIG. 12A, the acquisition system 30, in some
embodiments, may comprise the upper acquisition layer 60 and the
middle acquisition layer 62. As shown in FIG. 12B, the acquisition
system 30 may be configured as described above. Additionally, the
storage layer 24 may comprise multiple layers 24A and 24B.
[0118] In contrast to the incontinence pad 10 shown in FIG. 1, in
some embodiments, the incontinence pad 1200 may comprise a
substantially rectangular storage layer 24 and a substantially
rectangular upper acquisition layer 60. As discussed previously,
the size of the incontinence pad can vary greatly with panty size.
However, by manufacturing the middle acquisition layer 62 to the
desired size/shape based on the size of the panty, uniform sized
storage layers 24 and uniform sized upper acquisition layers 60 may
be utilized regardless of the size of the incontinence pad. By
utilizing uniform sized storage layers 24 and uniform upper
acquisition layers 60 across all sizes of panties, manufacturing
complexity and cost reductions may be achieved.
[0119] The storage layers and/or the acquisition layers described
herein may include any suitable shape known in the art. For
example, the shape of an acquisition layer can be different from
the shape of the storage layer. As another example, the shape of an
acquisition layer can be asymmetric about the lateral and/or
longitudinal axis of the incontinence pad 1200. As yet another
example, the shape of a storage layer can be asymmetric about the
lateral and/or longitudinal axis. As yet another example, an
acquisition layer can have a first width in the first region and a
second width in the second region. The first width can be less than
the second width, or vice versa. As yet another example, a first
acquisition layer can have a first acquisition shape, and a second
acquisition layer can have a second acquisition shape. The first
acquisition shape can be different from the second acquisition
shape.
[0120] Embodiments are contemplated where the upper acquisition
layer 60 and/or the middle acquisition layer 62 are manufactured to
a desired shape based on the size of the panty and wherein the
storage layer 24 is a uniform size throughout the varying sizes of
panties. Additionally, embodiments, are contemplated where the
storage layer 24 is manufactured in accordance with the shape of
the overall article and wherein the upper acquisition layer 60
and/or the middle acquisition layer 62 are uniformly sized across
all panty sizes. Additionally, embodiments are contemplated where
the upper acquisition layer 60 and the middle acquisition layer 62
are the same size.
[0121] Additionally, embodiments are contemplated where the surface
area of the acquisition layers vary with respect to each other
and/or with respect to the surface area of the storage layer 24.
For example, the surface area of an acquisition layer can be at
least 50% greater than the surface area of the storage layer. As
another example, the surface area of a first acquisition layer
and/or a second acquisition layer can be at least as much as a
surface area of the storage layer.
[0122] Similarly to the storage layer 24 may be constructed in a
number of different configurations. For example, as shown in FIG.
13, the storage layer 24 may include a substrate layer 70,
absorbent polymer material 72 and a fibrous layer of adhesive 80.
The substrate layer 70 can be provided from a non-woven material,
for example, those exemplified above for the layers 66, 68. The
absorbent polymer material 72 may be immobilized when wet such that
the absorbent core 22, in some embodiments, achieves a wet
immobilization of more than 50 percent, preferably of more than 60
percent, 70 percent, 80 percent or 90 percent according to the Wet
Immobilization Test described herein.
[0123] The substrate layer 70 has a first surface 76 and a second
surface 78. At least portions of the first surface 76 of the
substrate layer 70 are in direct contact with a layer of absorbent
polymer material 72.
[0124] The layer of absorbent polymer material 72 may be a
discontinuous layer. As used herein, a discontinuous layer is a
layer comprising areas where there is an absence of absorbent
polymer material. In some embodiments, these areas can have a
diameter or largest span of about 10 mm or less, about 5 mm or
less, about 3 mm or less, about 2 mm or less, and of about 0.5 mm
or more, at least about 1 mm or at least about 1.5 mm. The
absorbent polymer material 72 defines a certain height H of the
layer of absorbent polymer material 72 above the first surface 76
of the layer of substrate material 70. When the absorbent polymer
material 72 layer is provided as a discontinuous layer, portions of
the first surface of the substrate layer 70 may not be covered by
absorbent polymer material 72. In some embodiments, the absorbent
core 22 further comprises an adhesive 80 in the form of
thermoplastic composition. This thermoplastic composition 80 can
serve to at least partially immobilize the absorbent polymer
material 72.
[0125] The height H of the layer of absorbent polymer material 72
can be any suitable height. In some embodiments, the height H can
be lower than about 5 mm. In some embodiments, the height H can be
about 2.5 mm or lower.
[0126] In one embodiment, the thermoplastic composition 80 can be
disposed essentially uniformly within the polymeric absorbent
material 72. However, in some embodiments the thermoplastic
composition 80 can be provided as a fibrous layer which is
partially in contact with the absorbent polymer material 72 and
partially in contact with the substrate layer 70. As shown in FIG.
13, the absorbent polymer material 72 is provided as a
discontinuous layer, the layer of fibrous thermoplastic composition
80 is laid down onto the layer of absorbent polymeric material 72,
such that the thermoplastic composition 80 is in direct contact
with the first surface of the layer of absorbent polymer material
72, but also in direct contact with the first surface 76 of the
substrate layer 70 where the substrate layer 70 is not covered by
the absorbent polymeric material 72. This imparts an essentially
three-dimensional structure to the fibrous layer of thermoplastic
composition 80 which, in itself, is essentially a two-dimensional
structure of relatively small measured thickness.
[0127] The thermoplastic composition 80 can provide cavities 82 to
hold the absorbent polymer material 72, and thereby immobilizes
this material 72. In a further aspect, the thermoplastic
composition 80 bonds to the substrate layer 70 and thus can affix
the absorbent polymer material 72 to the substrate 70. In some
implementations, thermoplastic composition 80 may also penetrate
into both the absorbent polymer material 72 and the substrate layer
70, thus providing for further immobilization and affixation. While
the thermoplastic materials disclosed herein provide a much
improved wet immobilization (i e , immobilization of absorbent
material when the article is wet or at least partially loaded),
these thermoplastic materials also provide a very good
immobilization of absorbent material when the article is dry.
[0128] In some embodiments, the absorbent polymer material 72 may
also be mixed with absorbent fibrous material, such as comminuted
wood pulp generally referred to as airfelt material, which can
provide a matrix for further immobilization of the super-absorbent
polymer material. However, a relatively low amount of fibrous
cellulose material may be used, for example, less than about 40
weight percent, less than about 20 weight percent or less than
about 10 weight percent of cellulose fibrous material as compared
to the weight of absorbent polymer material 72. Substantially
airfelt free cores can be desired having about five weight percent
or less airfelt material, such as no airfelt material. As used
herein, the term "absorbent fibrous material" is not meant to refer
to any thermoplastic material even if such thermoplastic material
is fiberized and partially absorbent.
[0129] An alternative storage layer embodiment is shown in FIG. 14.
The storage layer 24' shown further comprises a cover layer 86.
This cover layer 86 may be provided of the same material as the
substrate layer 70, or may be provided from a different material.
Preferred materials for the cover layer 86 are non-woven materials,
typically the materials described above as useful for the layers 66
and 68. In this embodiment, portions of the cover layer 86 may bond
to portions of the substrate layer 70 via the thermoplastic
composition 80. Thereby, the substrate layer 70 together with the
cover layer 86 can provide cavities to immobilize the absorbent
polymer material 72.
[0130] With reference to FIGS. 13 and 14 the areas of direct
contact between the thermoplastic composition layer 80 and the
substrate material 72 are referred to as areas of junction 88. The
shape number and disposition of the areas of junction 88 will
influence the immobilization of the absorbent polymer material 72.
As shown in FIG. 15A, the areas of junction 88 may comprise a
circular shape, in some embodiments. However, the areas of junction
88 can be any suitable shape known in the art, suitable examples of
which include squared shape, rectangular shape, circular shape,
triangular shape, polygonal shape, or any combination thereof. In
embodiments where the areas of junction 88 comprise circular
shapes, the circular shapes can have a diameter of more than about
0.5 mm, more than about 1 mm, more than about 1.5 mm and of less
than about 10 mm, less than about 5 mm, less than about 3 mm, or
less than about 2 mm. If the areas of junction 88 are not of
circular shape, they may be of a size as to fit inside a circle of
any of the preferred diameters given above.
[0131] The areas of junction 88 can be disposed in a regular or
irregular pattern. For example, as shown in FIG. 15B, in some
embodiments, the areas of junction 88 may be disposed along lines
1530 and 1535. In some embodiments, the lines 1530 and 1535 may be
aligned with a longitudinal axis 1500 of the storage layer 24, or
alternatively they may have a certain angle 1520 in respect to
longitudinal edges 108, 110 of the storage layer 24.
[0132] The lines 1530 and 1535 can be found by drawing a line
through adjacent geometric centers of the areas of junction. For
the purposes of illustration, columns of areas of junction 88 run
generally parallel to the longitudinal axis 1500 of the storage
layer 24. Pick a reference area of junction 88A. Pick the most
adjacent areas of junction 88B and 88C. As shown, the areas of
junction 88B and 88C can be in the columns adjacent to the column
of the reference area of junction 88A. Note that in embodiments
where lines 1530 and 1535 are aligned with the longitudinal axis
1500, the most adjacent areas of junction 88 to the reference area
of junction 88A are in the same column as the reference area of
junction 88A.
[0133] Draw line 1530 from the geometric center of the reference
area of junction 88A to through the geometric centers of the
adjacent areas of junction 88B and 88C. Extend the line 1530 to the
longitudinal edges 108 and 110 of the storage layer 24. For areas
of junction disposed between the areas of junction 88B and the
longitudinal edge 110 and the area of junction 88C and the
longitudinal edge 108, the line 1530 should be adjusted so that on
average, the line 1530 cross through the geometric centers of as
many areas of junction along the line 1530 as possible.
[0134] It has been found, that a disposition along lines parallel
with the longitudinal edges 108, 110 of the storage layer 24 can
create channels in the longitudinal direction which lead to a
lesser wet immobilization. Therefore the areas of junction 88 are
arranged along lines 1530 and/or 1535 which may form the angle 1520
of about 20 degrees, about 30 degrees, about 40 degrees, or about
45 degrees with a longitudinal axis 1500 of the storage layer 24.
In some embodiments, the angle 1520 between the lines 1530 and 1535
of junctions 88 and the longitudinal axis 1500 of the storage layer
24 can be between about 10 degrees to about 45 degrees or any
individual number within the range. In some embodiments, the angle
1520 between the line 1530 and the longitudinal axis 1500 can be
greater than an angle between the line 1535 and the longitudinal
axis 1500 of the storage layer 24. In some embodiments, the angle
1520 between the line 1530 and the longitudinal axis 1500 can be
less than an angle between the line 1535 and the longitudinal axis
1500 of the storage layer 24.
[0135] Another preferred pattern for the areas of junction 88 is a
pattern comprising polygons, for example pentagons and hexagons or
a combination of pentagons and hexagons. Also preferred are
irregular patterns of areas of junction 88, which also have been
found to give a good wet immobilization.
[0136] Some fundamentally different patterns of areas of junctions
88 can be chosen in accordance with the present invention. For
example, in one embodiment the areas of junctions 88 can be
discrete and can be positioned within the areas of absorbent
material 72, like islands in a sea. The areas of absorbent
materials 72 are then referred to as connected areas. In an
alternative embodiment, the areas of junctions 88 can be connected.
Then, the absorbent material 72 can be deposited in a discrete
pattern, or in other words the absorbent material 72 represents
islands in a sea of thermoplastic material 80. Hence, a
discontinuous layer of absorbent polymer material 72 may comprise
connected areas of absorbent polymer material 72 or may comprise
discrete areas of absorbent polymer material 72. In some
embodiments, it has been found that absorbent cores providing for a
good wet immobilization can be formed by combining two layers as
shown in FIG. 13 and as described in the context thereof.
[0137] The thermoplastic layer 80 can be formed of any suitable
thermoplastic composition, such as adhesive thermoplastic
compositions, also referred to as hot melt adhesives. A variety of
thermoplastic compositions are suitable to immobilize absorbent
material.
[0138] Some initially thermoplastic materials may later lose their
thermoplasticity due to a curing step, e.g., initiated via heat, UV
radiation, electron beam exposure or moisture or other means of
curing, leading to the irreversible formation of a crosslinked
network of covalent bonds. Those materials having lost their
initial thermoplastic behavior are herein also understood as
suitable for forming thermoplastic composition 80.
[0139] Without wishing to be bound by theory it is believed that
those thermoplastic compositions which may be useful for
immobilizing the absorbent polymer material 72 are those that
combine sufficient cohesion and adhesion behavior. Sufficient
adhesion can ensure that the thermoplastic composition layer 80
maintains contact with the absorbent polymer material 72 and in
particular with the substrate 70. Sufficient adhesiveness can be a
challenge to achieve, namely when a non-woven substrate 70 is used.
Sufficient cohesion can ensure that the adhesive does not rupture,
in particular in response to external forces, and namely in
response to strain. The adhesive is subject to external forces when
the absorbent product has acquired liquid, which is then stored in
the absorbent polymer material 72 which in response swells. An
exemplary adhesive can allow for such swelling, without breaking
and without imparting too many compressive forces, which would
restrain the absorbent polymer material 72 from swelling.
Additionally, the adhesive should not rupture, which may
deteriorate the wet immobilization. In some instances,
thermoplastic compositions meeting these requirements have the
following features:
[0140] The thermoplastic composition may comprise, in its entirety,
a single thermoplastic polymer or a blend of thermoplastic
polymers, having a softening point, as determined by the ASTM
Method D-36-95 "Ring and Ball", in the range between 50.degree. C.
and 300.degree. C., or alternatively the thermoplastic composition
may be a hot melt adhesive comprising at least one thermoplastic
polymer in combination with other thermoplastic diluents such as
tackifying resins, plasticizers and additives such as
antioxidants.
[0141] In some embodiments, the thermoplastic polymer can have a
molecular weight (Mw) of more than 10,000 and a glass transition
temperature (Tg) usually below room temperature. Typical
concentrations of the polymer in a hot melt are in the range of
about 20 to about 40 percent by weight or any individual number
within the range. A wide variety of thermoplastic polymers are
suitable. Such thermoplastic polymers may be water insensitive.
Exemplary polymers are (styrenic) block copolymers including A-B-A
triblock structures, A-B diblock structures and (A-B)n radial block
copolymer structures wherein the A blocks are non-elastomeric
polymer blocks, typically comprising polystyrene, and the B blocks
are unsaturated conjugated diene or (partly) hydrogenated versions
of such. The B block is typically isoprene, butadiene,
ethylene/butylene (hydrogenated butadiene), ethylene/propylene
(hydrogenated isoprene), and mixtures thereof.
[0142] Other examples of suitable thermoplastic polymers that may
be employed are metallocene polyolefins, which are ethylene
polymers prepared using single-site or metallocene catalysts.
Therein, at least one co-monomer can be polymerized with ethylene
to make a copolymer, terpolymer or higher order polymer. Also
applicable are amorphous polyolefins or amorphous polyalphaolefins
(APAO) which are homopolymers, copolymers or terpolymers of C2 to
C8 alphaolefins.
[0143] In some embodiments, the thermoplastic resin can have a Mw
below 5,000 and a Tg usually above room temperature, typical
concentrations of the resin in a hot melt can be in the range of
about 30 to about 60 percent or any individual number within the
range. Additionally, in some embodiments, the plasticizer can have
a low Mw of typically less than 1,000 and a Tg below room
temperature, with a typical concentration of from about 0 to about
15 percent.
[0144] In some embodiments, the adhesive is present in the forms of
fibers throughout the core. For example, the fibers can have an
average thickness of from about 1 to about 50 micrometer or any
individual number within the range. Additionally, the fibers can
have an average length of about 5 mm to about 50 cm or any
individual number within the range. To improve the adhesion of the
thermoplastic composition 80 material to the substrate layer 70 or
to any other layer, in particular any other non-woven layer, such
layers may be pre-treated with an auxiliary adhesive. For example,
in some implementations, the adhesive will meet at least one, and
more preferably several or all of the parameters discussed
below.
[0145] The adhesive can have a storage modulus G' measured at
20.degree. C. of at least about 30,000 Pa and less than about
300,000 Pa or any individual number within the range. In some
embodiments, the adhesive can have a storage modulus G' measured at
20 degrees C. of preferably less than about 200,000 Pa or more
preferably less than about 100,000 Pa. The storage modulus G' at
20.degree. C. is a measure for the permanent "tackiness" or
permanent adhesion of the thermoplastic material used. Sufficient
adhesion will ensure a good and permanent contact between the
thermoplastic composition 80 material and for example the substrate
layer 70.
[0146] In a further aspect, the storage modulus G' measured at
60.degree. C. should be more than about 18,000 Pa and less than
about 300,000 Pa or any individual number within the range. In some
embodiments, the storage modulus G' measured at 60 degrees C. can
be more than about 24,000 Pa or more preferably more than about
30,000. The storage modulus measured at 60.degree. C. is a measure
for the form stability of the thermoplastic composition 80 material
at elevated ambient temperatures. This value is particularly
important if the absorbent pad 10 is used in a hot climate where
the thermoplastic composition 80 material would lose its integrity
if the storage modulus G' at 60.degree. C. is not sufficiently
high.
[0147] G' is typically measured using a rheometer 90 as
schematically shown in FIG. 16 for the purpose of general
illustration only. The rheometer 90 is capable of applying a shear
stress to the adhesive and measuring the resulting strain (shear
deformation) response at constant temperature. The adhesive is
placed between a Peltier-element acting as lower, fixed plate 92
and an upper plate 94 with a radius R of, e.g., 10 mm, which is
connected to the drive shaft of a motor to generate the shear
stress. The gap between both plates has a height H of, e.g., 1500
micron. The Peltier-element enables to control the temperature of
the material (+0.5.degree. C.).
[0148] In a further aspect, the loss angle tan delta of the
adhesive at 60.degree. C. can be below the value of about 1,
preferably below the value of about 0.5, in some embodiments. The
loss angle tan delta at 60.degree. C. is correlated with the liquid
character of an adhesive at elevated ambient temperatures. The
lower tan delta, the more an adhesive behaves like a solid rather
than a liquid, i.e., the lower its tendency to flow or to migrate
and the lower the tendency of an adhesive superstructure as
described herein to deteriorate or even to collapse over time. This
value may be particularly important if the absorbent pad 10 is used
in a hot climate.
[0149] In a further aspect, the adhesive can have a glass
transition temperature Tg of less than about 25.degree. C., e.g.,
less than about 22.degree. C., less than about 18.degree. C., and
less than about 15.degree. C. A low glass transition temperature Tg
is beneficial for good adhesion. In some instances, a low glass
transition temperature Tg ensures that the adhesive thermoplastic
material does not become too brittle.
[0150] In yet a further aspect, an adhesive can have a sufficiently
high cross-over temperature Tx. A sufficiently high cross-over
temperature Tx has, in some cases, been found beneficial for high
temperature stability of the thermoplastic layer and can ensure
performance of the absorbent pad 10 and in particular good wet
immobilization even under conditions of hot climates and high
temperatures. In some embodiments, Tx is above about 80.degree. C.,
such as above about 85.degree. C., such as above about 90.degree.
C.
[0151] In some embodiments, an adhesive material useful as a
thermoplastic material 80 as described herein will meet most or all
of the above parameters. Specific care must be taken to ensure that
the adhesive provides good cohesion and good adhesion at the same
time.
[0152] The process for producing preferred absorbent cores 22 may
include a number of steps. For example, the absorbent core 22 can
be laid down onto a laydown drum, which presents an uneven surface.
In a first process step the substrate layer 70 can be laid on to
the uneven surface. Due to gravity, or preferably by using a
vacuum, the substrate layer material can follow the contours of the
uneven surface and thereby the substrate layer material can assume
peaks and valleys. Onto this substrate layer 70 absorbent polymeric
material 72 is disposed by methods known in the art. The absorbent
polymer material 72 will accumulate in the valleys presented by the
substrate layer 70. In some embodiments, in a further process step
a hot melt adhesive can placed onto the absorbent polymer material
72.
[0153] Any adhesive application means known in the art can be used
to place the hot melt adhesive on to the absorbent polymer material
72. For example, the hot melt adhesive can be applied by a nozzle
system. A nozzle system can provide a relatively thin but wide
curtain of adhesive. This curtain of adhesive can then be placed
onto the substrate layer 70 and the absorbent polymer material 72.
As the peaks of the substrate layer 70 are less covered by
absorbent polymer material 72 the adhesive can make contact with
these areas of the substrate layer 70.
[0154] In an optional further process step a cover layer 86 can be
placed upon the substrate layer 70, the absorbent polymer material
72 and the hot melt adhesive layer. The cover layer 86 will be in
adhesive contact with the substrate layer 70 in the areas of
junction 88. In these areas of junction 88, the adhesive is in
direct contact with the substrate layer 70. The cover layer 86 will
typically not be in adhesive contact with the substrate layer 70
where the valleys of the substrate layer 70 are filled with
absorbent polymer material 72.
[0155] Alternatively the cover layer 86 can be laid down onto a
drum with an uneven surface and the substrate layer 70 can be added
in a consecutive process step. The embodiment shown in FIG. 13 can
be produced by such a process.
[0156] In one alternative embodiment, the cover layer 86 and the
substrate layer 70 can be provided from a unitary sheet of
material. The placing of the cover layer 86 onto the substrate
layer 70 will then involve the folding of the unitary piece of
material.
[0157] Hence, the uneven surface of the lay-down system, which, for
example, can be a lay-down drum, typically determines the
distribution of absorbent polymeric material 72 throughout the
storage layer 24 and likewise determines the pattern of areas of
junction 88. Alternatively, the distribution of absorbent polymeric
material 72 may be influenced by a vacuum.
[0158] The absorbent core can be formed utilizing storage layer 24,
such as those described above. In some instances, no further
materials wrapping the absorbent core 22, such as the top layer 66
and the bottom layer 68 are used. With reference to the embodiment
of FIG. 13, in one embodiment, the substrate layer 70 may provide
the function of the bottom layer 68 and the layer of fibrous
thermoplastic material 80 (or cover layer 86 of FIG. 14) may
provide the function of the top layer 66. With reference to FIG. 14
the cover layer 86 may provide the function of the top layer 66 and
the substrate layer 70 may provide the function of the bottom layer
68.
[0159] In some embodiments, the distribution of absorbent polymeric
material 72 varies along the storage layer 24, for example, in the
longitudinal direction. Hence, along the longitudinal axis of the
absorbent core 22, which is normally coincident with the
longitudinal axis 54 of the incontinence pad 10, the basis weight
of the absorbent polymer material 72 can change. In other
embodiments, distribution of absorbent polymeric material may not
be profiled and may be substantially constant along the
longitudinal axis of the absorbent core 22.
[0160] In some embodiments having a varying distribution of
absorbent polymer material 72, the basis weight of absorbent
polymer material 72 in at least one freely selected first square
measuring 1 cm.sup.2 is at least about 10 percent, or about 20
percent, or about 30 percent, or about 40 percent, or about 50
percent higher than the basis weight of absorbent polymer material
in at least one freely selected second square measuring 1
cm.sup.2.
[0161] Optionally, the absorbent core 22 can also comprise an
absorbent fibrous material, for example cellulose fibers. This
fibrous material can be pre-mixed with the absorbent polymeric
material 72 and be laid down in one process step or it can
alternatively be laid-down in separate process steps.
[0162] It has been found beneficial to use a particulate absorbent
polymer material 72 for absorbent cores 22. Without wishing to be
bound by theory it is believed that such material, even in the
swollen state, i.e., when liquid has been absorbed, does not
substantially obstruct the liquid flow throughout the material,
especially when the permeability as expressed by the saline flow
conductivity of the absorbent polymer material 72 is greater than
about 10, greater than about 20, greater than about 30, or greater
than about 40 SFC-units, where 1 SFC unit is 1.times.10.sup.-7
(cm.sup.3s)/g.
[0163] As to achieve a sufficient absorbent capacity (e.g., at
least about 1 g/cm.sup.2 or more of 0.9 percent NaCl solution, at
least about 2 g/cm.sup.2 or more of 0.9 percent NaCl solution, such
as between 2 g/cm.sup.2 and 4 g/cm.sup.2 of 0.9 percent NaCl
solution, such as about 2.5 g/cm.sup.2 of 0.9 percent NaCl
solution) in an incontinence pad 10, superabsorbent polymer
material 72 will be present with an average basis weight of about
50 g/m.sup.2 or more. In some embodiments, density of absorbent
material of the storage layer 24 may be about 400 g/m.sup.2, such
as about 500 g/m.sup.2, such as about 600 g/m.sup.2, such as about
700 g/m.sup.2, such as about 800 g/m.sup.2, such as about 900
g/m.sup.2.
[0164] In some embodiments, a storage layer 24 formed of regions of
absorbent polymer material 72 as described above may have a
relatively small dry caliper. In some embodiments, storage layer 24
may have a dry caliper of about 5 mm or less, such as about 4 mm or
less, such as about 2 mm or less and acquisition system 30 may have
a dry caliper of about 4 mm or less and form about 50 percent or
more of the total dry caliper of the incontinence pad 10. In some
embodiments, the storage layer 24 may expand to a caliper of about
5 times or more than its dry caliper as the storage layer 24
absorbs liquid. In some instances, the storage layer 24 may swell
to a caliper of about 2 cm or more at full capacity, such as
between about 2 cm and about 6 cm, such as about 2.5 cm or any
individual number within the range. In some embodiments, storage
layer 24 may have a dry caliper that is about 50 percent or less
(e.g., about 40 percent or less, about 30 percent or less, about 25
percent or less, about 20 percent or less, about 15 percent or
less, about 10 percent or less, about 5 percent or less, and the
like) of the total dry caliper of the absorbent core 22 and/or
incontinence pad 10. In some embodiments, at full capacity, the
storage layer 24 may swell to a wet caliper that is about 60
percent or greater (e.g., about 65 percent or greater, about 70
percent or greater, about 75 percent or greater, about 80 percent
or greater, about 85 percent or greater, about 90 percent or
greater) of the total caliper of the absorbent core 22 and/or
incontinence pad 10.
[0165] D. Absorbent Core Shape and Sizing
[0166] Referring now to FIG. 17, a preferred absorbent core 22
configuration including storage layer 24 and acquisition system 30
is shown. Absorbent core 22 may extend along a pair of axes, e.g.,
a longitudinal axis 100 and a lateral axis 102 that extends
substantially transverse to the longitudinal axis. Each axis 100,
102 extends through a point P' located at geometric center of the
absorbent core 22. In the illustrated embodiment, longitudinal axis
100 intersects each of end edges 104 and 106 and spans a maximum
length l of the absorbent core 22, while lateral axis 102
intersects side edges 108 and 110. In some embodiments, the
longitudinal axis 100 may not span the maximum length of the
storage layer 22. In certain instances, lateral axis 102 spans a
minimum width w of the absorbent core 22 (FIG. 1).
[0167] Periphery 112 of the storage layer 24 can define a core
shape. The periphery 112 may be formed by edges (e.g., edges 104,
106, 108, 110) of the substrate 70 of the storage layer 24 or, in
some cases, by a core wrap (e.g., core wrap 61, 63). As shown by
FIG. 17, the core shape, in some embodiments, can be asymmetric
about the lateral axis 102 in that the core shape is not
substantially identical on each side of the lateral axis 102. For
example, area A.sub.1' of the storage layer 24 can be substantially
greater than area A.sub.2'. In some embodiments, A.sub.1' may be
about five percent larger or more (e.g., about 10 percent larger,
about 15 percent larger, about 20 percent larger, etc.) than
A.sub.2'. The core shape of the storage layer 24 can be symmetric
about the longitudinal axis 100 in that the core shape is
substantially identical on each side of the longitudinal axis 100.
In an alternative embodiment, the core shape may be symmetric about
the lateral axis 102 in that the core shape is substantially
identical on each side of the lateral axis 102. In some
implementations, the core shape is asymmetric about the
longitudinal axis 100 in that the core shape is not substantially
identical on each side of the longitudinal axis 100.
[0168] In some embodiments, the core shape of the absorbent core 22
(including any or all of components, such as the storage layer 24,
forming the absorbent core) is a substantially similar shape to the
pad shape (represented by dotted lines) of the incontinence pad 10.
As used herein, similar shapes refer to figures having
substantially the same shape and a different size. Use of
superabsorbent material in the core 22 allows for a relatively
consistent core caliper, capacity and/or acquisition properties
regardless of core size. As a result, in accordance with certain
aspects of the invention, cores manufactured (e.g., having length
and width properties) to fit a small pad size (see Table II) can be
stretched, if desired, to be integrated into pads of larger sizes.
It should be appreciated that stretching the core 22 may
correspondingly reduce the core thickness (or caliper).
Advantageously, certain aspects of the present invention have
eliminated the need to separately manufacture various cores having
sizes and shapes configured for specific pad sizes. It should be
further appreciated that the core 22 need not be stretched.
Instead, because the core 22 provides suitable absorbency across
the range of pad sizes, a core sized to fit a given pad can be
attached as-is to larger pads so long as the core is properly
positioned for use.
[0169] As illustrated in Table II above, the core 22 can have a
caliper that remains substantially constant across the range of pad
sizes. The caliper can be anywhere at or between 3 mm, 4 mm, 5 mm,
6 mm, 7 mm, 8 mm, and 9 mm. In some embodiments, the core 22 (or
storage layer 24) having 1 of about 230 mm (e.g., corresponding to
a small pad size) may have a caliper of no more than about 50
percent (e.g., no more than about 40 percent, about 35 percent,
about 30 percent, about 25 percent, about 20 percent, about 15
percent, about 10 percent, about five percent, and about three
percent) greater than a core 22 (or storage layer 24) having an 1
of about 294 mm (e.g., corresponding to an extra large pad size),
while maintaining desired capacity and acquisition properties. In
some embodiments, there may be relatively little deviation in core
or storage layer caliper (e.g., no more than about 50 percent,
about 40 percent, about 35 percent, about 30 percent, about 25
percent, about 20 percent, about 15 percent, about 10 percent,
about five percent, and about three percent) between any two, any
three, any four, or even all pad sizes between the smallest size
available for purchase and the largest size available for purchase
as illustrated in Table II. Furthermore, the caliper of the core 22
may have substantially no variation (e.g., within 1 percent
caliper) from one pad size to the next.
[0170] More broadly stated, as a pad size increases from a first
size to a second size having a body-facing surface area between 5%
and 40% greater than the body-facing surface area of the first
size, the core thickness (or caliper) decreases by an amount less
than about 50 percent (alternatively less than about 40 percent,
about 35 percent, about 30 percent, about 25 percent, about 20
percent, about 15 percent, about 10 percent, about five percent,
and alternatively still about three percent).
[0171] E. Odor Management
[0172] One or more of the above-described components of the
incontinence pad 10, for example, the topsheet 16, backsheet 18,
absorbent core 22, acquisition system 30, and/or core wrap 63, etc.
may include a coating composition used to minimize odor caused from
bodily fluids, for example, through a starch encapsulated accord
(SEA) and a carrier. The SEA and carrier components can be present
in a weight ratio of carrier to SEA of equal to or greater than
1:1. In one optional embodiment, the coating composition comprises
from about 0 percent to about 10 percent by weight of coating
composition of water, or any individual number within the range. In
some embodiments, the coating composition comprises from about 0
percent to about 5 percent by weight of coating composition of
water. In one specific embodiment, the coating composition is
essentially free from water and contains only trace amounts of
water. This low water content provides added stability and extended
life to the SEAs, while also reducing manufacturing costs due to
reduced product loss.
[0173] The coating compositions may comprise optional ingredients,
such as but not limited to, aesthetic components, pigments and the
like. Some illustrative optional ingredients are described herein.
Desirably, at least an effective amount of the coating composition
is applied to the article. Effective amounts are typically those
which provide a noticeable scent signal to the consumer to signify
the substrate on which the coating composition is attached has been
contacted with sufficient aqueous fluid (e. g. , menses, urine,
etc.) or water containing solid (e.g., feces). In one optional
embodiment, when the substrate is a part of a disposable absorbent
article the typical amount of the coating composition present on
the substrate is from about 0.001 g to about 5 g or any individual
number within the range. In some embodiments, the amount of the
coating composition present on the substrate can be from about
0.005 g to about 1 g, or more preferably from about 0.01 g to about
0.5 g, per substrate.
[0174] The coating compositions include starch encapsulated accords
(SEAs). SEAs are solid particles comprising water-soluble cellular
matrixes containing perfume stably held in the cells. In some
embodiments, the SEAs may comprise perfume ranging from about 20
percent to about 60 percent by weight of the SEA or any individual
number within the range. In some embodiments, the SEAs may comprise
perfume from about 20 percent to about 50 percent by weight of the
SEA.
[0175] In some embodiments, the SEAs may comprise mainly
polysaccharide and/or polyhydroxy compounds, preferably from at
least about 20 percent by weight of the SEA. In some embodiments,
the SEAs may comprise from about 50 percent to about 80 percent by
weight of the SEA. In some embodiments, the SEAs may comprise from
about 20 percent to about 80 percent by weight of the SEA or any
individual number within the range.
[0176] In some embodiments, the SEAs may comprise optional adjunct
ingredients ranging from about 0 percent to about 5 percent, or any
individual number within the range. Some suitable examples of
adjunct ingredients include but are not limited to wetting agents,
process aids, flow agent and the like and any combinations thereof.
In some embodiments, the SEA may encapsulate a perfume.
[0177] As stated previously, in some embodiments, the SEAs may
comprise mainly polysaccharide and polyhydroxy compounds. The
polysaccharides can be higher polysaccharides of the non-sweet,
colloidally-soluble types, such as natural gums, e.g., gum arabic,
starch derivatives, dextrinized and hydrolyzed starches, and the
like. The polyhydroxy compounds can be preferably alcohols,
plant-type sugars, lactones, mono-ethers, and acetals.
[0178] The SEAs useful in the present invention can be prepared by
forming an aqueous phase of the polysaccharide and polyhydroxy
compound in proper proportions with added emulsifier if necessary
or desirable, emulsifying the perfumes in the aqueous phase, and
removing moisture while the mass is plastic or flowable (e.g., by
spray drying droplets of the emulsion), in some embodiments. In one
optional embodiment, it is desirable to have only minimal
non-encapsulated surface perfume, more preferably of less than
about 1 percent by weight of the SEAs.
[0179] In some embodiments, the SEAs can have a particle size of
from about 0.5 .mu.m to about 1000 .mu.m, or any individual number
within the range. In some embodiments, the SEAs can have an average
particle size of from about 1 .mu.m to about 300 .mu.m, or any
individual number within the range. In some embodiments, the SEAs
may have an average particle size of from about 1 .mu.m to about
500 .mu.m and an average particle size of from about 1 .mu.m to
about 100 .mu.m. In some embodiments, the SEAs can have a particle
size of from about 1 .mu.m to about 100 .mu.m and an average
particle size of from about 10 .mu.m to about 50 .mu.m. SEAs can be
obtained commercially, e.g., as IN-CAP from Polak's Frutal Works,
Inc., Middletown, N.Y.; and as Optilok System@ encapsulated
perfumes from Encapsulated Technology, Inc. , Nyack, N.Y. Other
examples of suitable SEAs are available from Haarmann & Reimer,
Teterboro, N.J. USA. The perfume ingredients and compositions may
be conventional and well known in the art. Selection of any perfume
component, or amount of perfume, can be based on functional and
aesthetic considerations.
[0180] An example of an SEA is an IN-CAP microcapsule sample,
obtainable from Polak's Frutal Works, Inc., having about 50 percent
perfume loading and particle size range of from about 3 .mu.m to
about 100 .mu.m. Major components of the perfume are highly
volatile components, such as citral and d-limonene.
[0181] Typically, the SEA is present in the coating composition in
an effective amount. An effective amount is that which is effective
to provide for effective mixing of the SEA and carrier as well as
to enable the coating composition to be delivered and attached to a
substrate. In some embodiments, the SEA can be present in the
coating compositions at levels from about 0.01 percent to about 99
percent by weight of the coating composition, or any individual
number within the range. In some embodiments, the SEA can be
present in the coating composition at levels from about 0.5 percent
to about 97 percent, or preferably from about 1.0 percent to about
98 percent, by weight of the coating composition.
[0182] The coating compositions comprise a carrier, which may be
capable of suspending the SEAs while having minimal or preferably
no interaction with the SEAs which cause the perfume to be
released. In some embodiments, the carrier is present in the
coating compositions at levels from about 0.01 percent to about 99
percent by weight of the coating composition, or any individual
number within the range. In some embodiments, the carrier can be
present in the coating composition at levels from about 0.5 percent
to about 97 percent, or preferably from about 1.0 percent to about
98 percent, by weight of the coating composition.
[0183] The carrier may be a liquid or it may be a solid which is a
liquid at the temperature which the process is performed. In one
optional embodiment the carrier is a polyalkylene glycol or
mixtures thereof, such as polyethylene glycol, having a weight
average molecular weights of from about 200 to about 20,000, from
about 200 and about 10,000, from about 200 and about 7,500, or from
about 400 and about 6,000 g/mole. Non-limiting examples of other
suitable polyalkylene glycols include: polypropylene glycols,
having weight average molecular weights of from about 600 to about
4,000g/mole; poly(tetramethylene glycol), having molecular weights
of from about 1,000 to about 10,000 g/mole; mixed polyalkylene
glycols such as poly(ethylene oxide-propylene oxide or EO/PO)
glycol having a weight average molecular weight of about 1,100
g/mole, and an EO/PO ratio of about 0.15:1; a poly(ethylene
oxide-propylene oxide) glycol having a weight average molecular
weight of about 3,440 g/mole, EO/PO ratio of about 0.33:1; a
poly(ethylene oxide-propylene oxide) glycol having a weight average
molecular weight of about 2,920 g/mole, EO/PO ratio of about 0.8:1;
a poly(ethylene oxide-propylene oxide) glycol having a weight
average molecular weight of about 13,333 g/mole, EO/PO ratio of
about 3:1; and a poly(ethylene oxide-propylene oxide) glycol having
a weight average molecular weight of about 8,750 g/mole, EO/PO
ratio of about 5:1; and mixed polyalkylene glycol block copolymers
such as HO--[CH2CH20]x-[CH2CH(CH3)O]y-[CH2CH20], --H and/or
HO--[CH(CH3)CH2O]y-[CH2CH2O]X--[CH2CH(CH3)O]y-H wherein the sum of
the y's ranges from about 15 to about 70, and the ratio of the sum,
of the x's to the sum of the y's is from about 1:10 to about 11:10,
more preferably from about 1:2 to about 1:1. Commercially available
examples of these materials include materials made by BASF
Corporation and sold under the trade names of Pluronic and Pluronic
R surfactants, respectively.
[0184] Other examples of suitable carriers include the Ci-C22,
preferably C1-C4 alkylated polyalkylene glycols[poly(alkylene
glycol)mono-and dialkyl ethers], RO-(R20) n-H and/or RO-(R20) n-R,
with each R being methyl, ethyl, propyl, or butyl; each R2 being a
C2-C4 alkylene group; and n ranging from about 1 to about 200, with
the percentage of polyalkylene glycol being preferably more than
about 50 percent.
[0185] Specific examples include: RO-[CH2CH (CH3)O] m-H, with R
being methyl, ethyl, propyl, or butyl; and m being from 1 to about
200; RO-(CH2CH2O) n-H, with each R being methyl, ethyl, propyl, or
butyl, methyl; and n being from about 2 to about 200, from about 15
to about 150, from about 15 to about 100; and/or RO--(CH2CH2O) n-R,
with each R being methyl, ethyl, propyl, or butyl; and n being from
about 2 to about 200, from about 15 to about 150, or from about 15
to about 100.
[0186] Other suitable carriers include Polyalkoxylated materials
having a weight average molecular weight of from about 200 to about
20,000 g/mole and the weight percent of the polyalkoxy portion
being from about 50 percent to about 99 percent. Specific examples
include: Tetronic and TetronicRO; and Varstat66 (D. TekonicW and
TetronicRW are block copolymeric surfactants, manufactured by BASF
Corporation. Varstat66 is sold by Sherex Chemical Company.
[0187] In one optional embodiment, the carrier may be an oil, which
is liquid or in the molten phase at the temperature which the
process is performed (i.e., a solid which is liquid at temperatures
at which the process is to be performed). Examples of suitable oils
include but are not limited to, mineral oil, light oil, white
mineral oil, vaseline, liquid petroleum, petrolatum, petrolatum gel
and combinations thereof. Other materials suitable for use as
carriers include, but are not limited to, polyols such as
glycerine/glycerol/glycerin (1,2,3-Propanetriol), paraffin waxes,
fatty alcohols, such as but not limited to stearyl alcohol and the
like, and combinations thereof. In another optional embodiment, the
carrier is selected from the group consisting of polyalkylene
glycols, preferably polyethylene glycols, alkoxylated nonionic
surfactants, mineral oil, polyols, paraffin waxes, and combinations
thereof. In another optional embodiment, the carrier is a
polyethylene glycol having a weight average molecular weight of
from about 100 to about 10,000, more preferably from about 200 to
about 7,500 g/mole. Carrier may include a mixture of possible
carriers.
[0188] Regardless of which carrier is to be used, the carrier
should be compatible with the SEA and suitable for the intended use
of the substrate to which it is attached. For example if the
substrate is to be incorporated into the topsheet 16, the carrier
needs to be compatible for use in the incontinence pad 10.
[0189] The weight ratio of the carrier to the SEA may be equal to
or greater than about 1:1, preferably from about 1:1 to about 10:1,
even more preferably from equal to or greater than about 1:1 to
about 5:1. It has been surprisingly found that this ratio is
critical to ensure the even suspension of the SEA in the carrier as
well as improving the processability, delivery and attachment of
the coating composition to a substrate. This relative relationship
(i.e., the ratio, between the carrier and SEA) provides a coating
composition which is easy to process and provides simple delivery
and good attachment to the substrate. The relationship between the
carrier and SEA also allows for effective delivery of the optimal
amount of SEA to a substrate thereby producing cost savings in raw
materials, and reducing losses of SEA during the various process
steps. The coating compositions are highly processable allowing for
efficient and simplified delivery of the SEA, in the coating
composition, to the substrate. For example, since the coating
composition is readily processable, the SEAs can be accurately
targeted for deposition onto a substrate (e.g., the deposition of
the coating composition can be easily limited to one or more
regions on the substrate without coating the entire substrate).
This is an additional cost saving as the targeted deposition of SEA
means it is possible to reduce the amount of SEA necessary, thereby
further reducing costs.
[0190] The coating compositions may optionally contain one or more
optional ingredients. Examples of these ingredients include, but
are not limited to: aesthetic components, pigments, colorings,
colorants, anti-caking agents, antifoaming agents, preservative,
dye, antimicrobial agents (e.g., quaternium-15, methyl paraben,
ethyl paraben, propyl paraben, DMDM hydantoin, Suttocide A, IPBC,
etc.), antioxidants, fluorescence agents, binders, fumed silica,
biological additives, buffering agents, bulking agents, chelating
agents, chemical additives, solvents (other than water), cosmetic
biocides, denaturants, humectants, opacifying agents, pH adjusters,
process aids, reducing agents, sequestrants, binders, thickeners,
hydrocolloids, zeolites, and the like.
[0191] Optional ingredients, when present, are each typically
employed in compositions at levels of from about 0.0001 percent to
about 99.9 percent by weight of the coating composition, or any
individual number within the range. In some embodiments, the
optional ingredients may be present in the composition at levels
from about 0.001 percent to about 99 percent, or preferably from
about 0.01 percent to about 97 percent, by weight of the coating
composition.
[0192] F. Visual Indicia
[0193] Referring to FIGS. 18-20, incontinence pad 10 may include
indicia 150 that are visible or at least partially visible through
topsheet 16. The indicia 150 may be printed on any layer where the
indicia is at least partially visible through the topsheet 16, such
as on the lower surface of the topsheet 16 opposite the body-facing
portion and/or on the upper surface of the acquisition system 30
facing the body-facing portion.
[0194] In some embodiments, indicia 150 may comprise a graphic that
includes colors such as violet, blue, lavender, white, and/or any
other suitable color and/or illustrations such as a pattern, for
example, of speckles or dots 152 that indicates an effective
quality of the incontinence pad 10. Without wishing to be bound by
theory, it has been observed that female incontinence pad users
identify certain colors such as lavender as indicating an
absorptive quality and certain patterns such as speckles as
indicating an odor management quality.
[0195] Referring to FIGS. 21 and 22, an embodiment is shown where
incontinence pad 10 is secured in a folded configuration, for
example, for packaging. Incontinence pad 10 has a wrapping sheet
300 affixed thereto using the adhesive of adhesive region 202. The
wrapping sheet 300 can be removed from the adhesive region 202 to
expose the adhesive region 202 for use. In the illustrated example,
incontinence pad 10 is folded in a tri-fold configuration having
three lateral portions 302, 304 and 306. Other folding
configurations are contemplated. A releasable fastener 308, such as
releasable tape, secures the incontinence pad 10/wrapping sheet 300
in the folded configuration.
[0196] Wrapping sheet 300 is releasable from the adhesive region
202. Referring to FIG. 23, in some embodiments, the wrapping sheet
300 may include an outer layer 310 (e.g., a non-woven material), an
intermediate, bonding layer 312 (e.g., polyethylene) and an inner
layer 314 (e.g., silicon). Referring to FIG. 24, as an alternative,
wrapping sheet 300 may include an outer layer 310 (e.g., a
non-woven material) and an inner layer 318 formed of a release
paper that is bonded to the outer layer 310.
[0197] G. Reinforcement Elements
[0198] Referring to FIGS. 25A and 25B, in some embodiments, the
incontinence pad 10 may further comprise a reinforcement element
2100. The reinforcement element 2100 can be utilized in any of the
embodiments discussed herein. As shown, the reinforcement element
2100 is utilized in an article similar to that described in FIG.
11B.
[0199] As shown in FIG. 25A, in some embodiments, the reinforcement
element 2100 may be disposed between the topsheet 16 and the
backsheet 18. Specifically, in the embodiment shown, the
reinforcement element 2100 may be disposed between the core cover
63 and the backsheet 18. The core cover 63 may be bonded to the
reinforcement element 2100 via adhesive elements 1150. Embodiments
are contemplated where the reinforcement element is disposed
between the topsheet 16 and the storage layer 24.
[0200] Additionally, embodiments are contemplated where the
reinforcement layer 2100 is disposed on a garment-facing surface of
the backsheet 18. In this specific embodiment, adhesive may be
applied to the reinforcement element 2100 and other portions of the
garment-facing surface of the incontinence pad 10 such that the
incontinence pad 10 can be joined to an undergarment.
[0201] The reinforcement element 2100 of the present invention may
assist in keeping the barrier leg cuffs 32 and 34 spaced apart. As
shown in FIG. 25A, the barrier leg cuff 32 includes an upstanding
edge 2102, and the barrier leg cuff 34 includes an upstanding edge
2104. The reinforcement element 2100 can assist in maintaining a
distance 2300 between the upstanding edge 2102 and the upstanding
edge 2104. In embodiments comprising a reinforcement element 2100,
the distance 2300 can be between about 40 mm to about 90 mm or any
individual number within the range. In some embodiments, the
distance can be between about 55 mm to about 75 mm.
[0202] As shown in FIG. 25B, the incontinence pad 10 is shown in a
flat configuration with the garment-facing surface 52 facing
towards the viewer. As shown, in some embodiments, the
reinforcement element 2100 can be disposed within an area 2112
between a first fold line 2002 and a second fold line 2004 of the
incontinence pad 10. The area 2112 can be bounded by the first fold
line 2002 and the second fold line 2004 as well as the side edges
48 and 50. The reinforcement element 2100 can be disposed within
the area 2112 in some embodiments. Additionally, in some
embodiments, the reinforcement element 2100 can be bounded by the
first fold line 2002 and/or the second fold line 2004 and/or the
side edge 48 and/or side edge 50.
[0203] The reinforcement element 2100 of the present invention may
comprise any suitable material known in the art. For example, the
reinforcement element 2100 may comprise a material made from
polyethylene, polypropylene, polyethylene teraphthalate, rubber,
urethane, cellulose, or any suitable combination thereof. In a
specific embodiment, the reinforcement element 2100 may comprise a
nonwoven having polyethylene teraphthalate fibers having resin
bonds. In another embodiment, the reinforcement element 2100 may
comprise a material which is similar to the material of an
acquisition layer described heretofore.
[0204] One benefit of the reinforcement element 2100 as shown in
FIG. 25B is that the folds along the fold lines 2002 and 2004 have
a reduced thickness compared to the thickness which would occur if
the reinforcement element 2100 extended the length of the
incontinence pad 10. Additionally, a reinforcement element 2100
extending the full length of the incontinence pad 10 may cause
wearer discomfort. Still another benefit is that the reinforcement
element 2100, as shown in FIG. 25B, can help hold the incontinence
pad 10 open, e.g., maintain the distance 2300, in the general
middle of the incontinence pad 10. Holding the incontinence pad 10
open can reduce the likelihood of leakage from the pad 10.
[0205] A number of detailed embodiments have been described.
Nevertheless, it will be understood that various modifications may
be made. For example, referring to FIGS. 33 and 34 adhesive region
202 can be formed from multiple, spaced-apart regions 202'. In some
embodiment, the adhesive region 202 shape is substantially similar
to the pad shape and/or the core shape. Accordingly, other
embodiments are contemplated. Further embodiments are contemplated
including elements of the embodiments presented herein in any
suitable combination.
[0206] H. Tests
[0207] Peel Strength
[0208] Peel strength is measured on a constant rate of extension
tensile tester with computer interface (a suitable instrument is a
MTS Synergie 200 under TestWorks 4 software, as available from MTS
Systems Corp., Eden Prairie, Minnesota) using a load cell for which
the forces measured are within 10% to 90% of the limit of the cell.
Both the movable (upper) and stationary (lower) pneumatic jaws are
fitted with rubber faced grips, wider than the width of the test
specimen.
[0209] For analysis, the specimen is mounted in the device detailed
in FIG. 28A and 28B. The device consists of a rigid steel mounting
plate 262 (253 mm long by 82 mm wide by 1.5 mm thick; 2700, 2701
and 2702 respectively) with a raised center region (177 mm long by
70 wide by 7.3 thick; 2703, 2704 and 2705 respectively). The
specimen is securely held in place using a plastic friction grip
frame 264 (226 mm long by 83 mm wide by 5.8 mm thick; 2710, 2711
and 2712 respectively) with a cut-out region (178 mm long by 71 mm
wide; 2713 and 2714 respectively). The cut-out is pressed down
around the raised surface of the steal plate and sandwiches the
specimen between the steel plate 262 and the friction grip frame
264.
[0210] A foam-padded weight 250 is constructed as shown in FIG. 26,
by laying a polyethylene film 252 (250 mm long by 150 mm wide by 25
.mu.m thick) flat on a bench surface. A piece of polyurethane foam
254 (140 mm long by 57 mm wide by 25 mm thick; available from
Concord-Renn Co. Cincinnati, Ohio, density of 1.0 lb/ft3, IDL 24
psi) is laid centered on top of the film. A piece of Plexiglas 256
(140 mm long by 57 mm wide by 6.4 mm thick) is then stacked on top
of the polyurethane foam. Next the polyethylene film 252 is used to
wrap the polyurethane foam and Plexiglas plate securing it with
transparent tape 255. A metal weight with handle 258 (140 mm long
by 57 mm wide) is stacked on top of, and fastened to, the Plexiglas
plate. The mass of the metal weight 258 is chosen such that the
total weight of the constructed foam-padded weight 250 is 4.14
Kg.
[0211] Place the sample article, topsheet down, on a flat bench.
Measure and mark the width of the adhesive zone which extends down
the center longitudinal axis of the article (lines 257 and 259 as
shown in FIG. 27). This zone can consist of a single adhesive
strip, a plurality of strips, or any other adhesive pattern.
Adhesive regions outside of the central longitudinal zone are not
included as part of the test specimen (e.g., triangle regions
outboard of lines 257 and 259). Cut a specimen strip 260 the entire
length of the article along lines 257 and 259, and remove the core
and topsheet. Allow the specimen to equilibrate to room temperature
for 10 minutes before proceeding.
[0212] Place the specimen 260 centered longitudinally and laterally
onto the steel mounting plate 262. As shown in FIG. 29, the plastic
friction grip frame 264 is pressed down over the raised portion of
the mounting plate 262 to sandwich the specimen 260 between the
frame and the steel plate. After the specimen is secure, remove the
release paper.
[0213] Referring to FIG. 30, lay a 457 mm long by 76 mm wide
standard cotton swatch 266 (white, 100% cotton weave, style #429-W
available from Test Fabrics, Inc. Middlesex, N.J.) over the
assembled mounting device. The cotton swatch 266 should extend the
length of the friction frame cut-out with an additional 25 mm or
more extending past the top of the frame. Gently and evenly place
the foam-padded weight 250, on the specimen as shown in FIG. 30.
The weight should cover the specimen completely. The weight remains
on the specimen for 30 seconds and then removed.
[0214] Less than 1 minute after removing the weight, place the
bottom of the steel plate 262 (labeled 270 in FIG. 30) into the
lower, stationary jaw of the tensile tester, and close the grip
faces. Fold the long end (labeled 272 in FIG. 30) of the cotton
swatch 266 back over itself and place into the upper, movable jaw
and close the grip faces. FIGS. 31A and 31B depict the proper
configuration for the test. Start the tensile tester and data
collection. The jaws are moved apart at an initial rate of 1016
mm/min until the cotton swatch is detached from the specimen. The
software is used to calculate the average Peel Force (N) between 58
mm and 170 mm from the resulting force/extension curve and reported
to the nearest 0.1 N.
Density/Caliper/Basis Weight Measurement
[0215] The caliper of a test specimen is measured using a digital
caliper (a suitable instrument is model # GS-503 available from Ono
Sokki). The foot has a diameter 4 cm with the anvil at least 2 cm
larger in diameter than the foot. The mass of the foot is chosen to
apply a pressure of 1.25 kPa. The specimen is placed between the
foot and anvil and a reading is taken after pressure has been
applied for 5 seconds. The thickness should be reported to the
nearest 0.01 mm as the average of three replicates.
[0216] The basis weight is determined in the typical fashion.
Conveniently, a 10 cm by 10 cm of the specimen is accurately cut to
the closest 0.5 mm and weighed on an analytical balance to the
nearest 0.001 g. Basis weight can then be calculated from the mass
and specimen area, and reported as g/m.sup.2. From the basis weight
and caliper measurements, the density can be calculated and
reported as g/m.sup.3.
[0217] These measurements should be repeated on at least three
specimens taken from the same sample, and reported as the average
value.
Wet Immobilization Measurement
[0218] The wet immobilization test is performed using a shaking
device as described herein and shown in FIG. 32. Ten absorbent
articles are analyzed for each test and the wet immobilization
value is reported as the average. Prior to testing, the percent of
Super-Absorbent Polymer (SAP) contained in the sample, and the
Centrifuge Retention Capacity (CRC) of that SAP must be
measured.
[0219] The shaker comprises a base 352, a height adjustable support
platform 356, and a vibration table 360. The base 352 is of
sufficient size and weight to provide stable shaking conditions.
The support platform 356 is mounted onto the base 352 with two
height adjustable legs 354a and 354b, which are adjusted to
accommodate the specific height of the specimen to be tested. The
vibration table 360 is mounted via rubber supports 358 to the
platform 356. The table 360 consist of a tray structure from which
the specimen can be hung vertically from a rigidly attached clamp
364 (dimensions: 1 inch by wider than the specimen), and an
electric motor 362. The motor 362 shakes the vibration table at a
frequency of 16.8 Hz with a vertical amplitude of 4 mm and a
horizontal amplitude of 1 mm relative to the support plate 356.
[0220] Prepare a specimen by removing all layers of the absorbent
article that do not directly wrap the SAP containing core (e.g.,
topsheet, backsheet, and any acquisition layers that do not contain
SAP). Care must be taken while removing the layers not to disturb
the integrity of the core. Measure the length of the core along its
longitudinal axis to the nearest 1 mm, and calculate an inset that
is 5% of the overall length. Measure this inset distance along the
longitudinal axis of the core, starting from its top edge, and draw
a transverse line across the width at that point. Repeat from the
bottom edge of the specimen. Cut the core along both lines, to
yield the test specimen. Measure and record the mass of the dry
specimen (M.sub.dry) on an analytical balance to the nearest 0.1
g.
[0221] The test solution used to wet the specimen is 0.9% (w/w)
saline solution that is heated to 37.degree. C. The volume of test
solution added is based on 50% of the capacity of the SAP present
in the specimen and is calculated as
M dry .times. % SAP 100 .times. CRC .times. 0.50 ##EQU00001##
and converted to mL based on a density of 1 g/mL.
[0222] Lay the specimen flat into a tray 350 (10 mm deep by about
10% greater than the size of the core), and slowly pour the
calculated volume of test solution onto the center of the pad.
Allow to equilibrate for 5 minutes and measure the wet specimen
mass (M1) on an analytical balance to the nearest 0.1 g.
[0223] Securely attach the top edge of the specimen to the
vibration table 360 by placing 20 mm of the specimen into the clamp
364. Adjust the height of the support platform so that the bottom
free end of the specimen is 40 mm above the base as it hangs
vertically. For convenience, place the tray 350 under the specimen
to catch core material that falls from the specimen. Start the
motor 362 and shake the specimen for 80 seconds. Next, remove the
specimen from the clamp 364, and place the opposite end of the
specimen into the clamp. If necessary, carefully reopen the free
end if it was sealed close from the pressure of the clamp during
the previous shaking step. Allow the specimen to again hang
vertically and start the motor to shake the specimen for an
additional 80 seconds. Remove the specimen from the clamp and
remeasure its mass (M2) to the nearest 0.1 g.
[0224] Calculate the Wet Immobilization Value (%) as
( M 1 - M 2 ) M 1 .times. 100 ##EQU00002##
for each of ten replicates and report the average to the nearest
1%.
Centrifuge Retention Capacity (CRC) Method
[0225] The Centrifuge Retention Capacity (CRC) test is a measure of
the retention of liquids by a SAP. The SAP is placed within a "tea
bag" immersed in a 0.9% (w/w) sodium chloride solution for 30
minutes, and then centrifuged for 3 minutes. The ratio of the
retained liquid weight and the initial weight of the dry material
is the CRC (g/g) of the SAP. The CRC test is performed under
standard laboratory conditions of 23.degree. C. .+-.2.degree. C.
and 50% .+-.2% relative humidity.
[0226] The teabag pouch is made from a 6 cm by 12 cm piece of tea
bag material (grade 1234 heat sealable material, available from the
Dexter Corporation, Windsor Locks, CN, or equivalent) that is
folded in half lengthwise and sealed along two sides with a T-bar
sealing device.
[0227] Accurately weigh 0.200 g .+-.0.005 g of SAP particles into a
tea bag pouch and seal the third (open) side. Seal an empty pouch
to use as a blank. Pour approximately 300 mL of 0.9% saline into a
1000 mL beaker and submerge the blank tea bag into the saline. Hold
the sample tea bag horizontally to distribute the particles within
the tea bag. Lay the sample tea bag on the surface of the saline
solution; then, using a spatula, submerged for about 5 seconds to
wet the sample. Soak the blank and sample tea bags for 30 minutes.
A second replicate, both sample and blank, is performed in parallel
in like fashion.
[0228] After 30 minutes, promptly remove the tea bags and place
into a centrifuge (a suitable instrument is the Delux Dynac II
Centrifuge from Fisher Scientific, fitted with a 22 cm diameter,
circular centrifuge basket). Space the replicate samples in the
basket to balance the centrifuge. Start the centrifuge and allow it
to quickly ramp up to a stable speed of 1500 rpm (250 g). After 3
minutes at 1500 rpm, turn the centrifuge off and apply the brake.
Remove the tea bags and immediately measure the mass of each teabag
and record to the nearest 0.001 g. The CRC is calculated as
( Mass sample tea bag - Mass blank tea bag - Mass dry SAP ) Mass
dry SAP ##EQU00003##
and is reported as the average value of the two replicates to the
nearest 0.01 g/g.
% Super Absorbent Polymer Method
[0229] SAPs distributed through out a SAP/cellulose fiber core can
be quantified based on the following concept. Neutralized or
partially neutralized polyacrylate based SAPs can be suspended in a
aqueous system and converted to the acid form by reaction with a
strong acid such as hydrochloric acid. If the acid form of the
polymer is then removed from the suspension, the reduction of
hydrogen ions in the remaining aqueous system can be taken as a
measure of the amount of neutralized or partially neutralized SAP
originally present.
[0230] Prepare a specimen by removing all layers of the absorbent
article that do not directly wrap the SAP containing core (e.g.,
topsheet, backsheet, and any acquisition layers). Measure the mass
of the specimen on an analytical balance to the nearest 0.01 g. Cut
the specimen in half and add both pieces to a known volume of
standardized hydrochloric acid. Mix the test specimen for 20
minutes using common mixing equipment. Remove a portion of the
suspension and filter it through Whatman #4 filter paper. Titrate
an aliquot of the filtrate with standardized sodium hydroxide to a
bromophenol blue endpoint (pH 4.5). Also titrate an acid blank in
like fashion. Normality of the standardized acid and base solutions
are adjusted based on the amount of SAP to be titrated. For example
a specimen containing 10 g of SAP could be diluted in 1 Liter of
0.1 N HCl, and a 50 mL filtered aliquot titrated with 0.1 N
NaOH.
[0231] Using a SAP compositionally identical to that found in the
absorbent article to be tested (this can be SAP from the production
run or SAP harvested from a second core by mechanical
manipulation), create a calibration curve of mass of dry SAP verses
the volume of NaOH titrated. Calculate the blank corrected amount
of SAP from the calibration curve and ratio it to the mass of the
original specimen. Report the %SAP (g/g) to the nearest 0.1%.
End of Test Methods
[0232] The dimensions and values disclosed herein are not to be
understood as being strictly limited to the exact numerical values
recited. Instead, unless otherwise specified, each such dimension
is intended to mean both the recited value and a functionally
equivalent range surrounding that value. For example, a dimension
disclosed as "40 mm" is intended to mean "about 40 mm".
[0233] All documents cited in the Detailed Description of the
Invention are, in relevant part, incorporated herein by reference,
however the citation of any document is not construed as an
admission that it is prior art with respect to the present
invention. To the extent that any meaning or definition of a term
in this written document conflicts with any meaning or definition
of the term in a document incorporated by reference, the meaning or
definition assigned to the term in this written document shall
govern.
[0234] While particular embodiments and/or individual features of
the present invention have been illustrated and described, it would
be obvious to those skilled in the art that various other changes
and modifications can be made without departing from the spirit and
scope of the invention. Further, it should be apparent that all
combinations of such embodiments and features are possible and can
result in preferred executions of the invention. Therefore, the
appended claims are intended to cover all such changes and
modifications that are within the scope of this invention.
* * * * *