U.S. patent application number 14/938093 was filed with the patent office on 2016-03-03 for absorbent articles with channels and/or pockets.
The applicant listed for this patent is The Procter & Gamble Company. Invention is credited to Carsten Heinrich KREUZER, Donald Carroll ROE, Maja WCIORKA.
Application Number | 20160058630 14/938093 |
Document ID | / |
Family ID | 49881030 |
Filed Date | 2016-03-03 |
United States Patent
Application |
20160058630 |
Kind Code |
A1 |
ROE; Donald Carroll ; et
al. |
March 3, 2016 |
Absorbent Articles with Channels and/or Pockets
Abstract
The present disclosure is directed, in part, to an absorbent
article comprising a front waist edge, a rear waist edge
longitudinally opposing the front waist edge, and a longitudinal
axis extending from a midpoint of the front waist edge to a
midpoint of the rear waist edge. The absorbent article comprises a
liquid permeable topsheet, a liquid impermeable backsheet, and an
absorbent core disposed at least partially intermediate the
topsheet and the backsheet. The absorbent core comprises a channel
substantially free of the superabsorbent polymers and at least
partially oriented in the longitudinal direction of the absorbent
article. The channel has lateral widths taken parallel to the
lateral axis. A profile of the lateral widths of the channel over a
longitudinal length of at least 50 mm of the channel taken along
the longitudinal axis is substantially constant.
Inventors: |
ROE; Donald Carroll; (West
Chester, OH) ; KREUZER; Carsten Heinrich; (Hofheim,
DE) ; WCIORKA; Maja; (Weddel, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Procter & Gamble Company |
Cincinnati |
OH |
US |
|
|
Family ID: |
49881030 |
Appl. No.: |
14/938093 |
Filed: |
November 11, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13709244 |
Dec 10, 2012 |
9216118 |
|
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14938093 |
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13709254 |
Dec 10, 2012 |
9216116 |
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13709244 |
|
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Current U.S.
Class: |
604/385.101 |
Current CPC
Class: |
A61F 13/532 20130101;
A61F 13/535 20130101; A61F 13/53 20130101; A61F 13/537 20130101;
A61F 13/514 20130101; A61F 2013/53051 20130101; A61F 13/495
20130101; A61F 2013/530868 20130101; A61F 13/511 20130101; A61F
13/49007 20130101; A61F 13/49001 20130101 |
International
Class: |
A61F 13/53 20060101
A61F013/53; A61F 13/49 20060101 A61F013/49 |
Claims
1. An absorbent article comprising: a front waist edge; a rear
waist edge longitudinally opposing the front waist edge; a
longitudinal axis extending from a midpoint of the front waist edge
to a midpoint of the rear waist edge; a liquid permeable topsheet;
a liquid impermeable backsheet; and an absorbent core disposed at
least partially intermediate the topsheet and the backsheet and
comprising a core wrap enclosing an absorbent material comprising
superabsorbent polymers, wherein the absorbent core comprises a
channel substantially free of the superabsorbent polymers and at
least partially oriented in the longitudinal direction of the
absorbent article, wherein the channel comprises: an arcuate
portion facing the longitudinal axis, wherein an angle between a
tangent line of the arcuate portion and the longitudinal axis is
greater than or equal to 20 degrees; and the channel has lateral
widths taken parallel to the lateral axis, wherein a profile of the
lateral widths of the channel over a longitudinal length of at
least 50 mm of the channel taken along the longitudinal axis is
substantially constant.
2. The absorbent article of claim 1, wherein the substantially
constant lateral width is in the range of about 5 mm to about 10
mm.
3. The absorbent article of claim 1, wherein the angle is greater
than or equal to 30 degrees.
4. The absorbent article of claim 1, wherein the absorbent core
comprises a second channel substantially free of the superabsorbent
polymers and at least partially oriented in the longitudinal
direction of the absorbent article, wherein the second channel has
lateral widths taken parallel to the lateral axis, and wherein the
second channel is positioned on an opposite side of the
longitudinal axis as the channel.
5. The absorbent article of claim 4, wherein a profile of the
lateral widths of the second channel over the longitudinal length
is substantially constant.
6. The absorbent article of claim 4, wherein a profile of the
lateral widths of the second channel over the longitudinal length
varies.
7. The absorbent article of claim 4, wherein the second channel has
a second arcuate portion facing the longitudinal axis, wherein a
second angle between a second tangent line taken from the second
arcuate portion and the longitudinal axis is greater than or equal
to 20 degrees, and wherein the second tangent line has a positive
or a negative slope.
8. The absorbent article of claim 4, wherein the channel is
symmetrical to the second channel about the longitudinal axis.
9. The absorbent article of claim 4, wherein the lateral widths of
the channel and the second channel are substantially the same at a
point along the channel and the second channel.
10. The absorbent article of claim 1, wherein the core wrap
comprises a first material and a second material, and the first and
second material are bonded to each other through a portion of the
channel.
11. An absorbent article comprising: a front waist edge; a rear
waist edge longitudinally opposing the front waist edge; a first
side edge; a second side edge laterally opposing the first side
edge; a longitudinal axis extending from a midpoint of the front
waist edge to a midpoint of the rear waist edge; a lateral axis
extending from a midpoint of the first side edge to a midpoint of
the second side edge; a liquid permeable topsheet; a liquid
impermeable backsheet; and an absorbent core disposed at least
partially intermediate the topsheet and the backsheet and
comprising: an absorbent material comprising superabsorbent
polymers; a first continuous channel substantially free of the
superabsorbent polymers and at least partially oriented in a
longitudinal direction of the absorbent article; and a second
continuous channel substantially free of the superabsorbent
polymers and at least partially oriented in the longitudinal
direction of the absorbent article,: wherein the first and second
channels are spaced apart by a minimum lateral distance of at least
5 mm; wherein the first and second channels each have lateral
widths taken parallel to the lateral axis, and wherein a profile of
the lateral widths of each channel over a longitudinal length of at
least 50 mm of the respective channel is substantially
constant.
12. The absorbent article of claim 11, wherein the first and second
channels are symmetrically arranged relative to the longitudinal
axis.
13. The absorbent article of claim 11, wherein the first and/or
second channel is curved.
14. The absorbent article of claim 11, comprising a core wrap
enclosing the absorbent material and having a first material and a
second material, wherein the first material is bonded to the second
material in the channels.
15. The absorbent article of claim 14, wherein the first material
forms a C-wrap only partially around the second material.
16. The absorbent article of claim 11, wherein the first channel
and the second channel have the same longitudinal length within the
absorbent article.
17. The absorbent article of claim 11, wherein the first and the
second channels are at least present at the same longitudinal level
as the lateral axis.
18. An absorbent article comprising: a front waist edge; a rear
waist edge longitudinally opposing the front waist edge; a first
side edge; a second side edge laterally opposing the first side
edge; a longitudinal axis extending from a midpoint of the front
waist edge to a midpoint of the rear waist edge; a lateral axis
extending from a midpoint of the first side edge to a midpoint of
the second side edge; a liquid permeable topsheet; a liquid
impermeable backsheet; and an absorbent core disposed at least
partially intermediate the topsheet and the backsheet and
comprising: an absorbent material comprising superabsorbent
polymers; a first continuous channel substantially free of the
superabsorbent polymers and at least partially oriented in a
longitudinal direction of the absorbent article; and a second
continuous channel substantially free of the superabsorbent
polymers and at least partially oriented in the longitudinal
direction of the absorbent article; wherein the first and second
channels are spaced apart by a minimum lateral distance of at least
5 mm; wherein the first and second channels each have lateral
widths taken parallel to the lateral axis, and wherein a profile of
the lateral widths of each channel over a longitudinal length of at
least 50 mm of the respective channel varies.
19. The absorbent article of claim 18, wherein the first and second
channels are symmetrically arranged relative to the longitudinal
axis.
20. The absorbent article of claim 18, wherein the first and/or
second channel is curved.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of, and claims priority
under 35 U.S.C. .sctn.120 to, U.S. patent application Ser. No.
13/709,244, filed on Dec. 10, 2012, and to U.S. patent application
Ser. No. 13/709,254, filed on Dec. 10, 2012, the entire disclosures
of which are hereby incorporated by reference.
FIELD
[0002] The present disclosure is generally directed to absorbent
articles for personal hygiene such as baby diapers, training pants,
adult incontinence products, and/or sanitary napkins. The absorbent
articles may each comprise channels and/or pockets.
BACKGROUND
[0003] Absorbent articles for personal hygiene, such as disposable
diapers for infants, training pants for toddlers, adult
incontinence undergarments, and/or sanitary napkins are designed to
absorb and contain body exudates, in particular large quantities of
urine or menses. These absorbent articles comprise several layers
providing different functions, for example, a topsheet, a
backsheet, and an absorbent core disposed between the topsheet and
the backsheet, among other layers.
[0004] The function of the absorbent core is to absorb and retain
the exudates for a prolonged amount of time, for example, overnight
for a diaper, minimize re-wet to keep the wearer dry, and avoid
soiling of clothes or bed sheets. The majority of currently
marketed absorbent articles comprise as absorbent material which is
a blend of comminuted wood pulp with superabsorbent polymers (SAP)
in particulate form, also called absorbent gelling materials (AGM).
Absorbent articles having a core consisting essentially of SAP as
absorbent material (so called "airfelt-free" cores) have also been
proposed but are less common than traditional mixed cores.
[0005] Some absorbent articles may typically comprise leg cuffs
which provide improved containment of liquids and other body
exudates. Leg cuffs may also be referred to as leg bands, side
flaps, barrier cuffs, or elastic cuffs. Usually, each leg cuff
comprises one or more elastic strings or elements comprised in the
chassis of the diaper, for example, between the topsheet and
backsheet in the area of the leg openings to provide an effective
seal while the absorbent article is in use. These elasticized
elements which are substantially planar with the chassis of the
absorbent article will be referred to herein as gasketing cuffs. It
is also usual for the leg cuffs to comprise raised elasticized
flaps, herein referred to as barrier leg cuffs, which improve the
containment of fluid in the leg-torso joint regions.
[0006] Absorbent articles generally have a high absorbent capacity
and the absorbent core may expand several times its weight and
volume. These increases may cause the absorbent articles to sag in
the crotch region as they become saturated with liquid, which may
cause the barrier leg cuffs to partially lose contact with the
wearer's skin. This may lead to a loss of functionality of the
barrier leg cuffs, with the increased possibly of leakage.
[0007] Although various solutions to this problem have been
proposed, the field can benefit from additional channel and/or
pocket configurations that improved leakage prevention in absorbent
articles.
SUMMARY
[0008] In an embodiment, the present disclosure is directed, in
part, to an absorbent article that may comprise a front waist edge
or a front edge, a rear waist edge or a rear edge longitudinally
opposing the front waist edge, a first side edge, a second side
edge laterally opposing the first side edge, a longitudinal axis
extending from a midpoint of the front waist edge to a midpoint of
the rear waist edge, and a lateral axis extending from a midpoint
of the first side edge to a midpoint of the second side edge. The
absorbent article may also comprise a liquid permeable topsheet, a
liquid impermeable backsheet, and a pair of barrier leg cuffs
extending at least partially between the front waist edge and the
rear waist edge on opposite sides of the longitudinal axis. Each
barrier leg cuff may comprise a proximal edge joined to the
topsheet or the backsheet and a free terminal edge. The absorbent
article may also comprise an absorbent core disposed at least
partially intermediate the topsheet and the backsheet and may
comprise a core wrap enclosing an absorbent material. The absorbent
material may comprise at least 80% of superabsorbent polymers by
weight of the absorbent material. The absorbent core may comprise a
first channel substantially free of the superabsorbent polymers and
at least partially oriented in the longitudinal direction of the
article. The absorbent core may comprise a second channel
substantially free of the superabsorbent polymers and at least
partially oriented in the longitudinal direction of the article.
The first and second channels each have lateral widths taken
parallel to the lateral axis. The absorbent core may comprise a
pocket that is substantially free of the superabsorbent polymers
and that has a portion on the longitudinal axis. The pocket has
lateral widths taken parallel to the lateral axis. A profile of the
sum of the lateral widths of the first and second channels and the
lateral widths of the pocket over a longitudinal length of at least
50 mm taken along the longitudinal axis may have two separate
substantially constant portions. Other embodiments are also within
the scope of the present disclosure, including embodiments for
sanitary napkins.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The above-mentioned and other features and advantages of the
present disclosure, and the manner of attaining them, will become
more apparent and the disclosure itself will be better understood
by reference to the following description of non-limiting
embodiments of the disclosure taken in conjunction with the
accompanying drawings, wherein:
[0010] FIG. 1 is a top view of an absorbent article with some
layers partially removed in accordance with a non-limiting
embodiment of the present disclosure;
[0011] FIG. 2 is a cross-sectional view of the absorbent article
taken about line 2-2 of FIG. 1 in accordance with a non-limiting
embodiment of the present disclosure;
[0012] FIG. 3 is a view of the absorbent article of FIG. 2 where
the absorbent article has been loaded with fluid in accordance with
a non-limiting embodiment of the present disclosure;
[0013] FIG. 4 is a top view of another absorbent article with some
layers partially removed in accordance with a non-limiting
embodiment of the present disclosure;
[0014] FIG. 5 is a cross-sectional view of the absorbent article
taken about line 5-5 of FIG. 4 in accordance with a non-limiting
embodiment of the present disclosure;
[0015] FIG. 6 is a top view of an absorbent core of the absorbent
article of FIG. 4 with some layers partially removed in accordance
with a non-limiting embodiment of the present disclosure;
[0016] FIG. 7 is a cross-sectional view of the absorbent core taken
about line 7-7 of FIG. 6 in accordance with a non-limiting
embodiment of the present disclosure;
[0017] FIG. 8 is a cross-sectional view of the absorbent core taken
about line 8-8 of FIG. 6 in accordance with a non-limiting
embodiment of the present disclosure;
[0018] FIG. 9 is a top view of an absorbent core for an absorbent
article in accordance with a non-limiting embodiment of the present
disclosure;
[0019] FIG. 10 is a profile of the sum of the lateral widths of two
channels of FIG. 9 graphed against the longitudinal length of the
channels within the enclosed area "EA" in accordance with a
non-limiting embodiment of the present disclosure;
[0020] FIG. 11 is a profile of the sum of the lateral widths of
portions of the channels of FIG. 1 graphed against the longitudinal
length of the channels between lines A and B of FIG. 1 in
accordance with a non-limiting embodiment of the present
disclosure;
[0021] FIG. 12 is a top view of an absorbent core for an absorbent
article in accordance with a non-limiting embodiment of the present
disclosure;
[0022] FIG. 13 is a profile of the sum of the lateral widths of
portions of the channels and the pocket of FIG. 12 graphed against
the longitudinal length of the channels between lines C and D of
FIG. 12 in accordance with a non-limiting embodiment of the present
disclosure;
[0023] FIGS. 14-21 are top views of absorbent cores for absorbent
articles in accordance with various non-limiting embodiments of the
present disclosure; and
[0024] FIG. 22 is a top view of an absorbent article that is a
sanitary napkin with some of the layers cut away in accordance with
a non-limiting embodiment of the present disclosure.
DETAILED DESCRIPTION
[0025] Various non-limiting embodiments of the present disclosure
will now be described to provide an overall understanding of the
principles of the structure, function, manufacture, and use of the
absorbent articles with channel configurations and methods for
making the same disclosed herein. One or more examples of these
non-limiting embodiments are illustrated in the accompanying
drawings. Those of ordinary skill in the art will understand that
the absorbent articles with channel configurations and methods for
making the same described herein and illustrated in the
accompanying drawings are non-limiting example embodiments and that
the scope of the various non-limiting embodiments of the present
disclosure are defined solely by the claims. The features
illustrated or described in connection with one non-limiting
embodiment may be combined with the features of other non-limiting
embodiments. Such modifications and variations are intended to be
included within the scope of the present disclosure.
Introduction
[0026] As used herein, the term "absorbent article" refers to
disposable devices such as infant, child, or adult diapers,
training pants, sanitary napkins, and the like which are placed
against or in proximity to the body of the wearer to absorb and
contain the various exudates discharged from the body. Typically,
these articles comprise a topsheet, backsheet, an absorbent core,
optionally an acquisition system (which may be comprised of one or
several layers), and typically other components, with the absorbent
core normally placed at least partially between the backsheet and
the acquisition system or between the topsheet and the backsheet.
The absorbent articles of the present disclosure will be further
illustrated in the below description and in the Figures in the form
of a taped diaper. Nothing in this description should be, however,
considered limiting the scope of the claims. As such the present
disclosure applies to any suitable form of absorbent articles
(e.g., training pants, adult incontinence products, sanitary
napkins).
[0027] A "nonwoven web" as used herein means a manufactured sheet,
web, or batt of directionally or randomly orientated fibers, bonded
by friction, and/or cohesion, and/or adhesion, excluding paper and
products which are woven, knitted, tufted, stitch-bonded
incorporating binding yarns or filaments, or felted by wet-milling,
whether or not additionally needled. The fibers may be of natural
or man-made origin and may be staple or continuous filaments or be
formed in situ. Commercially available fibers may have diameters
ranging from less than about 0.001 mm to more than about 0.2 mm and
may come in several different forms such as short fibers (known as
staple, or chopped), continuous single fibers (filaments or
monofilaments), untwisted bundles of continuous filaments (tow),
and twisted bundles of continuous filaments (yam). Nonwoven webs
can be formed by many processes such as meltblowing, spunbonding,
solvent spinning, electrospinning, carding, and airlaying. The
basis weight of nonwoven webs is usually expressed in grams per
square meter (g/m.sup.2 or gsm).
[0028] The term "joined" or "bonded" or "attached", as used herein,
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.
General Description of the Absorbent Article
[0029] An example absorbent article according to the present
disclosure in the form of an infant diaper 20 is represented in
FIGS. 1-3. FIG. 1 is a plan view of the example diaper 20, in a
flat-out state, with portions of the structure being cut-away to
more clearly show the construction of the diaper 20. This diaper 20
is shown for illustration purpose only as the present disclosure
may be used for making a wide variety of diapers or other absorbent
articles.
[0030] The absorbent article may comprise a liquid permeable
topsheet 24, a liquid impermeable backsheet 25, an absorbent core
28 positioned at least partially intermediate the topsheet 24 and
the backsheet 25, and barrier leg cuffs 34. The absorbent article
may also comprise an acquisition-distribution system ("ADS") 50,
which in the example represented comprises a distribution layer 54
and an acquisition layer 52, which will be further detailed below.
The absorbent article may also comprise elasticized gasketing cuffs
32 joined to the chassis of the absorbent article, typically via
the topsheet and/or backsheet, and substantially planar with the
chassis of the diaper.
[0031] The Figures also show typical taped diaper components such
as a fastening system comprising adhesive tabs 42 attached towards
the rear edge of the article and cooperating with a landing zone 44
on the front of the article. The absorbent article may also
comprise other typical elements, which are not represented, such as
a rear elastic waist feature, a front elastic waist feature,
transverse barrier cuff(s), and/or a lotion application, for
example.
[0032] The absorbent article 20 comprises a front waist edge 10, a
rear waist edge 12 longitudinally opposing the front waist edge 10,
a first side edge 3, and a second side edge 4 laterally opposing
the first side edge 3. The front waist edge 10 is the edge of the
article which is intended to be placed towards the front of the
user when worn, and the rear waist edge 12 is the opposite edge.
The absorbent article may have a longitudinal axis 80 extending
from the lateral midpoint of the front waist edge 10 to a lateral
midpoint of the rear waist edge 12 of the article and dividing the
article in two substantially symmetrical halves relative to the
longitudinal axis 80, with article placed flat and viewed from
above as in FIG. 1. The absorbent article may also have a lateral
axis 90 extending from the longitudinal midpoint of the first side
edge 3 to the longitudinal midpoint of the second side edge 4. The
length L of the article may be measured along the longitudinal axis
80 from the front waist edge 10 to the rear waist edge 12. The
width of the article may be measured along the lateral axis 90 from
the first side edge 3 to the second side edge 4. The article may
comprise a crotch point C defined herein as the point placed on the
longitudinal axis at a distance of two fifth (2/5) of L starting
from the front edge 10 of the article 20. The article may comprise
a front waist region 5, a rear waist region 6, and a crotch region
7. The front waist region, the rear waist region, and the crotch
region each define 1/3 of the longitudinal length of the absorbent
article.
[0033] The topsheet 24, the backsheet 25, the absorbent core 28,
and the other article components may be assembled in a variety of
configurations, in particular by gluing or heat embossing, for
example. Example diaper configurations are described generally in
U.S. Pat. No. 3,860,003, U.S. Pat. No. 5,221,274, U.S. Pat. No.
5,554,145, U.S. Pat. No. 5,569,234, U.S. Pat. No. 5,580,411, and
U.S. Pat. No. 6,004,306. The absorbent article may be thin. The
caliper at the crotch point C or in the crotch region 7 of the
article may be, for example, from 4.0 mm to 12.0 mm or
alternatively from 6.0 mm to 10.0 mm.
[0034] The absorbent core 28 may comprise an absorbent material
comprising at least 80% by weight, at least 90% by weight, at least
95% by weight, or at least 99% by weight of superabsorbent polymers
and a core wrap enclosing the superabsorbent polymers. The core
wrap may typically comprise two materials, substrates, or nonwoven
materials 16 and 16' for the top side and bottom side of the core.
The core may comprises one or more channels, represented in FIG. 1
as the four channels 26, 26' and 27, 27'.
[0035] These and other components of the articles will now be
discussed in more details.
Topsheet
[0036] The topsheet 24 is the part of the absorbent article that is
directly in contact with the wearer's skin. The topsheet 24 can be
joined to the backsheet 25, the core 28 and/or any other layers as
is known to those of skill in the art. Usually, the topsheet 24 and
the backsheet 25 are joined directly to each other in some
locations (e.g., on or close to the periphery of the article) and
are indirectly joined together in other locations by directly
joining them to one or more other elements of the article 20.
[0037] The topsheet 24 may be compliant, soft-feeling, and
non-irritating to the wearer's skin. Further, at least a portion of
the topsheet 24 may be liquid permeable, permitting liquids to
readily penetrate through its thickness. A suitable topsheet may be
manufactured from a wide range of materials, such as porous foams,
reticulated foams, apertured plastic films, or woven or nonwoven
materials of natural fibers (e.g., wood or cotton fibers),
synthetic fibers or filaments (e.g., polyester or polypropylene or
bicomponent PE/PP fibers or mixtures thereof), or a combination of
natural and synthetic fibers. If the topsheet 24 includes fibers,
the fibers may be spunbond, carded, wet-laid, meltblown,
hydroentangled, or otherwise processed as is known in the art, in
particular spunbond PP nonwoven. A suitable topsheet comprising a
web of staple-length polypropylene fibers is manufactured by
Veratec, Inc., a Division of International Paper Company, of
Walpole, Mass. under the designation P-8.
[0038] Suitable formed film topsheets are also described in U.S.
Pat. No. 3,929,135, U.S. Pat. No. 4,324,246, U.S. Pat. No.
4,342,314, U.S. Pat. No. 4,463,045, and U.S. Pat. No. 5,006,394.
Other suitable topsheets 30 may be made in accordance with U.S.
Pat. Nos. 4,609,518 and 4,629,643 issued to Curro et al. Such
formed films are available from The Procter & Gamble Company of
Cincinnati, Ohio as "DRI-WEAVE" and from Tredegar Corporation,
based in Richmond, Va., as "CLIFF-T".
[0039] Any portion of the topsheet 24 may be coated with a lotion
as is known in the art. Examples of suitable lotions include those
described in U.S. Pat. No. 5,607,760, U.S. Pat. No. 5,609,587, U.S.
Pat. No. 5,643,588, U.S. Pat. No. 5,968,025, and U.S. Pat. No.
6,716,441. The topsheet 24 may also include or be treated with
antibacterial agents, some examples of which are disclosed in PCT
Publication WO95/24173. Further, the topsheet 24, the backsheet 25
or any portion of the topsheet or backsheet may be embossed and/or
matte finished to provide a more cloth like appearance.
[0040] The topsheet 24 may comprise one or more apertures to ease
penetration of exudates therethrough, such as urine and/or feces
(solid, semi-solid, or liquid). The size of at least the primary
aperture is important in achieving the desired waste encapsulation
performance. If the primary aperture is too small, the waste may
not pass through the aperture, either due to poor alignment of the
waste source and the aperture location or due to fecal masses
having a diameter greater than the aperture. If the aperture is too
large, the area of skin that may be contaminated by "rewet" from
the article is increased. Typically, the total area of the
apertures at the surface of a diaper may have an area of between
about 10 cm.sup.2 and about 50 cm.sup.2 or between about 15
cm.sup.2 and 35 cm.sup.2. Examples of apertured topsheets are
disclosed in U.S. Pat. No. 6,632,504, assigned to BBA NONWOVENS
SIMPSONVILLE. WO2011/163582 also discloses suitable colored
topsheet having a basis weight of from 12 to 18 gsm and comprising
a plurality of bonded points. Each of the bonded points has a
surface area of from 2 mm.sup.2 to 5 mm.sup.2 and the cumulated
surface area of the plurality of bonded points is from 10 to 25% of
the total surface area of the topsheet.
[0041] Typical diaper topsheets have a basis weight of from about
10 to about 21 gsm or from about 12 to about 18 gsm, but other
basis weights are within the scope of the present disclosure.
Backsheet
[0042] The backsheet 25 is generally that portion of the article 20
positioned adjacent the garment-facing surface of the absorbent
core 28 and which prevents, or at least inhibits, the exudates
absorbed and contained therein from soiling articles such as
bedsheets and undergarments. The backsheet 25 is typically
impermeable, or at least substantially impermeable, to liquids
(e.g., urine). The backsheet may, for example, be or comprise a
thin plastic film such as a thermoplastic film having a thickness
of about 0.012 mm to about 0.051 mm. Example backsheet films
include those manufactured by Tredegar Corporation, based in
Richmond, Va., and sold under the trade name CPC2 film. Other
suitable backsheet materials may include breathable materials which
permit vapors to escape from the diaper 20 while still preventing,
or at least inhibiting, exudates from passing through the backsheet
25. Example breathable materials may include materials such as
woven webs, nonwoven webs, composite materials such as film-coated
nonwoven webs, microporous films such as manufactured by Mitsui
Toatsu Co., of Japan under the designation ESPOIR NO and by
Tredegar Corporation of Richmond, Va., and sold under the
designation EXAIRE, and monolithic films such as manufactured by
Clopay Corporation, Cincinnati, Ohio under the name HYTREL blend
P18-3097.
[0043] The backsheet 25 may be joined to the topsheet 24, the
absorbent core 28, and/or any other element of the diaper 20 by any
attachment methods known to those of skill in the art. Suitable
attachment methods are described above with respect to methods for
joining the topsheet 24 to other elements of the article 20. For
example, the attachment methods may include using a uniform
continuous layer of adhesive, a patterned layer of adhesive, or an
array of separate lines, spirals, or spots of adhesive. Suitable
attachment methods comprising an open pattern network of filaments
of adhesive as disclosed in U.S. Pat. No. 4,573,986. Other suitable
attachment methods include using several lines of adhesive
filaments which are swirled into a spiral pattern, as is
illustrated by the apparatus and methods shown in U.S. Pat. No.
3,911,173, U.S. Pat. No. 4,785,996, and U.S. Pat. No. 4,842,666.
Adhesives which have been found to be satisfactory are manufactured
by H. B. Fuller Company of St. Paul, Minn. and marketed as HL-1620
and HL 1358-XZP. Alternatively, the attachment methods may comprise
using heat bonds, pressure bonds, ultrasonic bonds, dynamic
mechanical bonds, or any other suitable attachment methods or
combinations of these attachment methods as are known to those of
skill in the art.
Absorbent Core
[0044] As used herein, the term "absorbent core" refers to the
individual component of the article having the most absorbent
capacity and comprising an absorbent material and a core wrap
enclosing the absorbent material. The term "absorbent core" does
not include the acquisition-distribution system or layer or any
other component of the article which is not either integral part of
the core wrap or placed within the core wrap. The core may
comprise, consist essentially of, or consist of, a core wrap,
absorbent material as defined below, and glue enclosed within the
core wrap.
[0045] The absorbent core 28 of the present disclosure may comprise
an absorbent material with a high amount of superabsorbent polymers
(herein abbreviated as "SAP") enclosed within a core wrap. The SAP
content may represent 70%-100% or at least 70%, 75%, 80%, 85%, 90%,
95%, 99%, or 100% by weight of the absorbent material contained in
the core wrap. The core wrap is not considered as absorbent
material for the purpose of assessing the percentage of SAP in the
absorbent core.
[0046] By "absorbent material" it is meant a material which has
some absorbency property or liquid retaining properties, such as
SAP, cellulosic fibers as well as synthetic fibers. Typically,
glues used in making absorbent cores have no absorbency properties
and are not considered as absorbent material. The SAP content may
be higher than 80%, for example at least 85%, at least 90%, at
least 95%, at least 99%, and even up to and including 100% of the
weight of the absorbent material contained within the core wrap.
This provides a relatively thin core compared to conventional core
typically comprising between 40-60% SAP and high content of
cellulose fibers. The absorbent material may in particular
comprises less than 15% or less than 10% weight percent of natural
or synthetic fibers, less than 5% weight percent, less than 3%
weight percent, less than 2% weight percent, less than 1% weight
percent, or may even be substantially free of natural and/or
synthetic fibers. The absorbent material may advantageously
comprise little or no airfelt (cellulose) fibers, in particular the
absorbent core may comprise less than 15%, 10%, 5%, 3%, 2%, 1%
airfelt (cellulose) fibers by weight of the absorbent core, or may
even be substantially free of cellulose fibers.
[0047] The example absorbent core 28 of the absorbent article of
FIGS. 4-5 is shown in isolation in FIGS. 6-8. The absorbent core
may comprises a front side 280, a rear side 282, and two
longitudinal sides 284, 286 joining the front side 280 and the rear
side 282. The absorbent core may also comprise a generally planar
top side and a generally planar bottom side. The front side 280 of
the core is the side of the core intended to be placed towards the
front waist edge 10 of the absorbent article. The core 28 may have
a longitudinal axis 80' corresponding substantially to the
longitudinal axis 80 of the article, as seen from the top in a
planar view as in FIG. 1. In an embodiment, the absorbent material
may be distributed in higher amount towards the front side than
towards the rear side as more absorbency may be required at the
front in particular articles. In an embodiment, the front and rear
sides of the core may be shorter than the longitudinal sides of the
core. The core wrap may be formed by two nonwoven materials,
substrates, laminates, or other materials, 16, 16' which may be at
least partially sealed along the sides of the absorbent core. The
core wrap may be at least partially sealed along its front side
280, rear side 282, and two longitudinal sides 284, 286 so that
substantially no absorbent material leaks out of the absorbent core
wrap. The first material, substrate, or nonwoven 16 may at least
partially surround the second material, substrate, or nonwoven 16'
to form the core wrap, as illustrated in FIG. 7. The first material
16 may surround a portion of the second material 16' proximate to
the first and second side edges 284 and 286.
[0048] The absorbent core of the present disclosure may comprise
adhesive, for example, to help immobilizing the SAP within the core
wrap and/or to ensure integrity of the core wrap, in particular
when the core wrap is made of two or more substrates. The core wrap
may extend to a larger area than strictly needed for containing the
absorbent material within.
[0049] Cores comprising relatively high amount of SAP with various
core designs are disclosed in U.S. Pat. No. 5,599,335 (Goldman), EP
1,447,066 (Busam), WO 95/11652 (Tanzer), U.S. Pat. Publ. No.
2008/0312622A1 (Hundorf), and WO 2012/052172 (Van Malderen).
[0050] The absorbent material may be a continuous layer present
within the core wrap. In other embodiments, the absorbent material
may be comprised of individual pockets or stripes of absorbent
material enclosed within the core wrap. In the first case, the
absorbent material may be, for example, obtained by the application
of a single continuous layer of absorbent material. The continuous
layer of absorbent material, in particular of SAP, may also be
obtained by combining two absorbent layers having discontinuous
absorbent material application pattern, wherein the resulting layer
is substantially continuously distributed across the absorbent
particulate polymer material area, as disclosed in U.S. Pat. Appl.
Pub. No. 2008/0312622A1 (Hundorf), for example. The absorbent core
28 may comprise a first absorbent layer and a second absorbent
layer. The first absorbent layer may comprise the first material 16
and a first layer 61 of absorbent material, which may be 100% or
less of SAP. The second absorbent layer may comprise the second
material 16' and a second layer 62 of absorbent material, which may
also be 100% or less of SAP. The absorbent core 28 may also
comprise a fibrous thermoplastic adhesive material 51 at least
partially bonding each layer of absorbent material 61, 62 to its
respective material 16 or 16'. This is illustrated in FIGS. 7-8, as
an example, where the first and second SAP layers have been applied
as transversal stripes or "land areas" having the same width as the
desired absorbent material deposition area on their respective
substrate before being combined. The stripes may comprise different
amount of absorbent material (SAP) to provide a profiled basis
weight along the longitudinal axis of the core 80. The first
material 16 and the second material 16' may form the core wrap.
[0051] The fibrous thermoplastic adhesive material 51 may be at
least partially in contact with the absorbent material 61, 62 in
the land areas and at least partially in contact with the materials
16 and 16'in the junction areas. This imparts an essentially
three-dimensional structure to the fibrous layer of thermoplastic
adhesive material 51, which in itself is essentially a
two-dimensional structure of relatively small thickness, as
compared to the dimension in length and width directions. Thereby,
the fibrous thermoplastic adhesive material may provide cavities to
cover the absorbent material in the land area, and thereby
immobilizes this absorbent material, which may be 100% or less of
SAP.
[0052] The thermoplastic adhesive material 51 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., and/or the thermoplastic adhesive
material may be a hotmelt adhesive comprising at least one
thermoplastic polymer in combination with other thermoplastic
diluents such as tackifying resins, plasticizers and additives such
as antioxidants.
[0053] The thermoplastic adhesive used for the fibrous layer may
have elastomeric properties, such that the web formed by the fibers
on the SAP layer is able to be stretched as the SAP swell. Example
elastomeric, hotmelt adhesives include thermoplastic elastomers
such as ethylene vinyl acetates, polyurethanes, polyolefin blends
of a hard component (generally a crystalline polyolefin such as
polypropylene or polyethylene) and a Soft component (such as
ethylene-propylene rubber); copolyesters such as poly (ethylene
terephthalate-co-ethylene azelate); and thermoplastic elastomeric
block copolymers having thermoplastic end blocks and rubbery mid
blocks designated as A-B-A block copolymers: mixtures of
structurally different homopolymers or copolymers, e.g., a mixture
of polyethylene or polystyrene with an A-B-A block copolymer;
mixtures of a thermoplastic elastomer and a low molecular weight
resin modifier, e.g., a mixture of a styrene-isoprenestyrene block
copolymer with polystyrene; and the elastomeric, hot-melt,
pressure-sensitive adhesives described herein. Elastomeric,
hot-melt adhesives of these types are described in more detail in
U.S. Pat. No. 4,731,066 issued to Korpman on Mar. 15, 1988.
[0054] The thermoplastic adhesive material may be applied as
fibers. The fibers may have an average thickness of about 1 to
about 50 micrometers or about 1 to about 35 micrometers and an
average length of about 5 mm to about 50 mm or about 5 mm to about
30 mm, specifically reciting all 0.1 micrometer increments within
the above-specified ranges and any ranges formed therein or
thereby. To improve the adhesion of the thermoplastic adhesive
material to the materials 16 or 16' or to any other layer, in
particular any other nonwoven layers, such layers may be
pre-treated with an auxiliary adhesive. The fibers adhere to each
other to form a fibrous layer, which can also be described as a
mesh.
Superabsorbent Polymer (SAP)
[0055] "Superabsorbent polymers" ("SAP"), as used herein, refer to
absorbent materials which are cross-linked polymeric materials that
can absorb at least 10 times their weight of an aqueous 0.9% saline
solution as measured using the Centrifuge Retention Capacity (CRC)
test (EDANA method WSP 241.2-05E). The SAP used may have a CRC
value of more than 20 g/g, more than 24 g/g, from 20 to 50 g/g,
from 20 to 40 g/g, or from 24 to 30 g/g, specifically reciting all
0.1 g/g increments within the above-specified ranges and any ranges
created therein or thereby. The SAP useful with the present
disclosure may include a variety of water-insoluble, but
water-swellable polymers capable of absorbing large quantities of
fluids.
[0056] The superabsorbent polymer may be in particulate form so as
to be flowable in the dry state. Particulate absorbent polymer
materials may be made of poly(meth)acrylic acid polymers. However,
starch-based particulate absorbent polymer material may also be
used, as well polyacrylamide copolymer, ethylene maleic anhydride
copolymer, cross-linked carboxymethylcellulose, polyvinyl alcohol
copolymers, cross-linked polyethylene oxide, and starch grafted
copolymer of polyacrylonitrile. The superabsorbent polymer may be
polyacrylates and polyacrylic acid polymers that are internally
and/ or surface cross-linked. Suitable materials are described in
the PCT Patent Application Nos. WO 07/047598, WO 07/046052,
WO2009/155265, and WO2009/155264, for example. In some embodiments,
suitable superabsorbent polymer particles may be obtained by
generally known production processes as described in WO
2006/083584, for example. The superabsorbent polymers may be
internally cross-linked, i.e., the polymerization is carried out in
the presence of compounds having two or more polymerizable groups
which can be free-radically copolymerized into the polymer network.
Useful crosslinkers include, for example, ethylene glycol
dimethacrylate, diethylene glycol diacrylate, allyl methacrylate,
trimethylolpropane triacrylate, triallylamine, tetraallyloxyethane
as described in EP-A 530 438, di- and triacrylates as described in
EP-A 547 847, EP-A 559 476, EP-A 632 068, WO 93/21237, WO
03/104299, WO 03/104300, WO 03/104301, and in DE-A 103 31 450,
mixed acrylates which, as well as acrylate groups, include further
ethylenically unsaturated groups, as described in DE-A 103 31 456
and DE-A 103 55 401, or crosslinker mixtures as described, for
example, in DE-A 195 43 368, DE-A 196 46 484, WO 90/15830, and WO
02/32962 as well as cross-linkers described in WO2009/155265. The
superabsorbent polymer particles may be external surface
cross-linked, or post cross-linked. Useful post-crosslinkers
include compounds including two or more groups capable of forming
covalent bonds with the carboxylate groups of the polymers. Useful
compounds include for example alkoxysilyl compounds,
polyaziridines, polyamines, polyamidoamines, di- or polyglycidyl
compounds as described in EP-A 083 022, EP-A 543 303 and EP-A 937
736, polyhydric alcohols as described in DE-C 33 14 019, cyclic
carbonates as described in DE-A 40 20 780, 2-oxazolidone and its
derivatives, such as N-(2-hydroxyethyl)-2-oxazolidone as described
in DE-A 198 07 502, bis- and poly-2-oxazolidones as described in
DE-A 198 07 992, 2-oxotetrahydro-1,3-oxazine and its derivatives as
described in DE-A 198 54 573, N-acyl-2-oxazolidones as described in
DE-A 198 54 574, cyclic ureas as described in DE-A 102 04 937,
bicyclic amide acetals as described in DE-A 103 34 584, oxetane and
cyclic ureas as described in EP1,199,327 and morpholine-2,3-dione
and its derivatives as described in WO03/031482.
[0057] In some embodiments, the SAP may be formed from polyacrylic
acid polymers or polyacrylate polymers, for example, having a
neutralization degree of from 60% to 90%, or of about 75%, having,
for example, sodium counter ions.
[0058] The SAP useful for the present disclosure may be of numerous
shapes. The term "particles" refers to granules, fibers, flakes,
spheres, powders, platelets and other shapes and forms known to
persons skilled in the art of superabsorbent polymer particles. In
some embodiments, the SAP particles can be in the shape of fibers,
i.e., elongated, acicular superabsorbent polymer particles. In
those embodiments, the superabsorbent polymer particles fibers may
have a minor dimension (i.e., diameter of the fiber) of less than
about 1 mm, usually less than about 500 .mu.m, or less than 250
.mu.m down to 50 .mu.m, specifically reciting all 1 .mu.m
increments within the above-specified ranges and any ranges formed
therein or thereby. The length of the fibers may be about 3 mm to
about 100 mm, specifically reciting all 1 mm increments within the
above-specified range and any ranges formed therein or thereby. The
fibers may also be in the form of a long filament that may be
woven.
[0059] SAP may be spherical-like particles. In contrast to fibers,
"spherical-like particles" have a longest and a smallest dimension
with a particulate ratio of longest to smallest particle dimension
in the range of 1-5, where a value of 1 would equate a perfectly
spherical particle and 5 would allow for some deviation from such a
spherical particle. The superabsorbent polymer particles may have a
particle size of less than 850 .mu.m, from 50 to 850 .mu.m, from
100 to 710 .mu.m, or from 150 to 650 .mu.m, specifically reciting
all 1 .mu.m increments within the above-specified ranges and any
ranges formed therein or thereby, as measured according to EDANA
method WSP 220.2-05. SAP having a relatively low particle size may
help to increase the surface area of the absorbent material which
is in contact with liquid exudates and therefore supports fast
absorption of liquid exudates.
[0060] The SAP may have a particle sizes in the range from 45 .mu.m
to 4000 .mu.m, more specifically a particle size distribution
within the range of from 45 .mu.m to about 2000 .mu.m, or from
about 100 .mu.m to about 1000, 850 or 600 .mu.m, specifically
reciting all 1 .mu.m increments within the above-specified ranges
and any ranges formed therein or thereby. The particle size
distribution of a material in particulate form can be determined,
for example, by means of dry sieve analysis (EDANA 420.02 "Particle
Size distribution).
[0061] In some embodiments herein, the superabsorbent material may
be in the form of particles with a mass medium particle size up to
2 mm, between 50 microns and 2 mm or to 1 mm, or from 100 .mu.m,
200 .mu.m, 300 .mu.m, 400 .mu.m, 500 .mu.m, 1000 .mu.m, 800 .mu.m,
or 700 .mu.m; as can, for example, be measured by the method set
out in for example EP-A-0,691,133. In some embodiments of the
present disclosure, the superabsorbent polymer material is in the
form of particles whereby at least 80% by weight are particles of a
size between 50 .mu.m and 1200 .mu.m and having a mass median
particle size between any of the range combinations above. In
addition, or in another embodiment of the present disclosure, the
particles may be essentially spherical. In yet another or
additional embodiment of the present disclosure, the superabsorbent
polymer material may have a relatively narrow range of particle
sizes, e.g., with the majority (e.g., at least 80%, at least 90%,
at least 95%, or even at least 99% by weight) of particles having a
particle size between 50 .mu.m and 1000 .mu.m, between 100 .mu.m
and 800 .mu.m, or between 200 .mu.m and 600 .mu.m, specifically
reciting all 1 .mu.m increments within the above-specified ranges
and any ranges formed therein or thereby.
[0062] The surface of the SAP may be coated, for example, with a
cationic polymer. Certain cationic polymers may include polyamine
or polyimine materials. In some embodiments, the SAP may be coated
with chitosan materials such as those disclosed in U.S. Pat. No.
7,537,832 B2. In some other embodiments, the SAP may comprise
mixed-bed Ion-Exchange absorbent polymers such as those disclosed
in WO 99/34841 and WO 99/34842.
[0063] The absorbent core may comprise one or more types of
SAP.
[0064] For most absorbent articles, liquid discharges from a wearer
occur predominately in the front half of the article, in particular
for a diaper. The front half of the article (as defined by the
region between the front edge and a transversal line placed at a
distance of half L from the front waist edge 10 or rear waist edge
12 may therefore comprise most of the absorbent capacity of the
core. Thus, at least 60% of the SAP, or at least 65%, 70%, 75%,
80%, or 85% of the SAP may be present in the front half of the
absorbent article, the remaining SAP being disposed in the rear
half of the absorbent article. In other embodiments, the SAP
distribution may be uniform through the core or may have other
suitable distributions.
[0065] The total amount of SAP present in the absorbent core may
also vary according to expected user. Diapers for newborns may
require less SAP than infant, child, or adult incontinence diapers.
The amount of SAP in the core may be about 5 to 60 g or from 5 to
50 g, specifically reciting all 0.1 increments within the specified
ranges and any ranged formed therein or thereby. The average SAP
basis weight within the (or "at least one", if several are present)
deposition area 8 of the SAP may be at least 50, 100, 200, 300,
400, 500 or more g/m.sup.2. The areas of the channels (e.g., 27,
27') present in the absorbent material deposition area 8 are
deduced from the absorbent material deposition area to calculate
this average basis weight.
Core Wrap
[0066] The core wrap may be made of a single substrate, material,
or nonwoven folded around the absorbent material, or may comprise
two (or more) substrates, materials, or nonwovens which are
attached to another. Typical attachments are the so-called C-wrap
and/or sandwich wrap. In a C-wrap, as illustrated, for example, in
FIGS. 2 and 7, the longitudinal and/or transversal edges of one of
the substrates are folded over the other substrate to form flaps.
These flaps are then bonded to the external surface of the other
substrate, typically by gluing.
[0067] The core wrap may be formed by any materials suitable for
receiving and containing the absorbent material. Typical substrate
materials used in the production of conventional cores may be used,
in particular paper, tissues, films, wovens or nonwovens, or
laminates or composites of any of these. The core wrap may be
formed by a nonwoven web, such as a carded nonwoven, spunbond
nonwoven ("S") or meltblown nonwoven ("M"), and laminates of any of
these. For example, spunmelt polypropylene nonwovens may be
suitable, in particular those having a laminate web SMS, or SMMS,
or SSMMS, structure, and having a basis weight range of about 5 gsm
to about 15 gsm. Suitable materials are disclosed in U.S. Pat. No.
7,744,576, U.S. Pat. Publ. No. 2011/0268932A1, U.S. Pat. Publ. No.
2011/0319848A1, and U.S. Pat. Publ. No. 2011/0250413A1. Nonwoven
materials provided from synthetic fibers may also be used, such as
PE, PET, and/or PP, for example.
[0068] If the core wrap comprises a first substrate, nonwoven or
material 16 and a second substrate, nonwoven, or materials 16'
these may be made of the same type of material, may be made of
different materials, or one of the substrates may be treated
differently than the other to provide it with different properties.
As the polymers used for nonwoven production are inherently
hydrophobic, they may be coated with hydrophilic coatings if placed
on the fluid receiving side of the absorbent core. It may be
advantageous that the top side of the core wrap, i.e., the side
placed closer to the wearer in the absorbent article, be more
hydrophilic than the bottom side of the core wrap. A possible way
to produce nonwovens with durably hydrophilic coatings is via
applying a hydrophilic monomer and a radical polymerization
initiator onto the nonwoven, and conducting a polymerization
activated via UV light resulting in monomer chemically bound to the
surface of the nonwoven. An alternative possible way to produce
nonwovens with durably hydrophilic coatings is to coat the nonwoven
with hydrophilic nanoparticles, e.g., as described in WO
02/064877.
[0069] Permanently hydrophilic nonwovens are also useful in some
embodiments. Surface tension, as described in U.S. Pat. No.
7,744,576 (Busam et al.), can be used to measure how permanently a
certain hydrophilicity level is achieved. Liquid strike through, as
described in U.S. Pat. No. 7,744,576, may be used to measure the
hydrophilicity level. The first and/or second substrate may have a
surface tension of at least 55, at least 60, or at least 65 mN/m or
higher when wetted with saline solution. The substrate may also
have a liquid strike through time of less than 5 seconds for a
fifth gush of liquid. These values can be measured using the test
methods described in U.S. Pat. No. 7,744,576B2: "Determination Of
Surface Tension" and
[0070] "Determination of Strike Through" respectively.
[0071] Hydrophilicity and wettability are typically defined in
terms of contact angle and the strike through time of the fluids,
for example, through a nonwoven fabric. This is discussed in detail
in the American Chemical Society publication entitled "Contact
angle, wettability and adhesion", edited by Robert F. Gould
(Copyright 1964). A substrate having a lower contact angle between
the water and the surface of substrate may be said to be more
hydrophilic than another.
[0072] The substrates may also be air-permeable. Films useful
herein may therefore comprise micro-pores. The substrate may have
an air-permeability of from 40 or from 50, to 300 or to 200
m.sup.3/(m.sup.2.times.min), as determined by EDANA method 140-1-99
(125 Pa, 38.3 cm.sup.2). The material of the core wrap may
alternatively have a lower air-permeability, e.g., being
non-air-permeable, for example, to facilitate handling on a moving
surface comprising vacuum.
[0073] The core wrap may be at least partially sealed along all the
sides of the absorbent core so that substantially no absorbent
material leaks out of the core. By "substantially no absorbent
material" it is meant that less than 5%, less than 2%, less than
1%, or about 0% by weight of absorbent material escape the core
wrap. The term "seal" is to be understood in a broad sense. The
seal does not need to be continuous along the whole periphery of
the core wrap but may be discontinuous along part or the whole of
it, such as formed by a series of seal points spaced on a line. A
seal may be formed by gluing and/or thermal bonding.
[0074] If the core wrap is formed by two substrates 16, 16', four
seals may be used to enclose the absorbent material 60 within the
core wrap. For example, a first substrate 16 may be placed on one
side of the core (the top side as represented in the Figures) and
extend around the core's longitudinal edges to at least partially
wrap the opposed bottom side of the core. The second substrate 16'
may be present between the wrapped flaps of the first substrate 16
and the absorbent material 60. The flaps of the first substrate 16
may be glued to the second substrate 16' to provide a strong seal.
This so called C-wrap construction may provide benefits such as
improved resistance to bursting in a wet loaded state compared to a
sandwich seal. The front side and rear side of the core wrap may
then also be sealed by gluing the first substrate and second
substrate to another to provide complete encapsulation of the
absorbent material across the whole of the periphery of the core.
For the front side and rear side of the core, the first and second
substrates may extend and may be joined together in a substantially
planar direction, forming for these edges a so-called sandwich
construction. In the so-called sandwich construction, the first and
second substrates may also extend outwardly on all sides of the
core and be sealed flat, or substantially flat, along the whole or
parts of the periphery of the core typically by gluing and/or
heat/pressure bonding. In an embodiment, neither the first nor the
second substrates need to be shaped, so that they can be
rectangularly cut for ease of production but other shapes are
within the scope of the present disclosure.
[0075] The core wrap may also be formed by a single substrate which
may enclose as in a parcel wrap the absorbent material and be
sealed along the front side and rear side of the core and one
longitudinal seal.
SAP Deposition Area
[0076] The absorbent material deposition area 8 may be defined by
the periphery of the layer formed by the absorbent material 60
within the core wrap, as seen from the top side of the absorbent
core. The absorbent material deposition area 8 may have various
shapes, in particular, a so-called "dog bone" or "hour-glass"
shape, which shows a tapering along its width towards the middle or
"crotch" region of the core. In this way, the absorbent material
deposition area 8 may have a relatively narrow width in an area of
the core intended to be placed in the crotch region of the
absorbent article, as illustrated in FIG. 1. This may provide
better wearing comfort. The absorbent material deposition area 8
may thus have a width (as measured in the transversal direction) at
its narrowest point which is less than about 100 mm, 90 mm, 80 mm,
70 mm, 60 mm, or even less than about 50 mm. This narrowest width
may further be at least 5 mm, or at least 10 mm, smaller than the
width of the deposition area 8 at its largest point in the front
and/or rear regions deposition area 8. The absorbent material
deposition area 8 may also be generally rectangular, for example as
shown in FIGS. 4-6, but other deposition areas, such as a "T," "Y,"
"sand-hour," or "dog-bone" shapes are also within the scope of the
present disclosure.
[0077] The basis weight (amount deposited per unit of surface) of
the SAP may also be varied along the deposition area 8 to create a
profiled distribution of absorbent material, in particular SAP, in
the longitudinal direction, in the transversal direction, or both
directions of the core. Hence, along the longitudinal axis of the
core, the basis weight of absorbent material may vary, as well as
along the transversal axis, or any axis parallel to any of these
axes. The basis weight of SAP in areas of relatively high basis
weight may thus be at least 10%, 20%, 30%, 40%, or 50% higher than
in an area of relatively low basis weight. In one embodiment, the
SAP present in the absorbent material deposition area 8 at the
level of the crotch point C may have more SAP per unit of surface
deposited as compared to another area of the absorbent material
deposition area 8.
[0078] The absorbent material may be deposited using known
techniques, which may allow relatively precise deposition of SAP at
relatively high speed. In particular, the SAP printing technology
as disclosed in U.S. Pat. Publ. No. 2008/0312617 and U.S. Pat.
Publ. No. 2010/0051166A1 (both to Hundorf et al.) may be used. This
technique uses a printing roll to deposit SAP onto a substrate
disposed on a grid of a support which may include a plurality of
cross bars extending substantially parallel to and spaced from one
another so as to form channels extending between the plurality of
cross-bars. This technology allows high-speed and precise
deposition of SAP on a substrate. The channels of the absorbent
core may be formed for example by modifying the pattern of the grid
and receiving drums so that no SAP is applied in areas
corresponding to the channels. EP application number 11169396.6
discloses this modification in more details.
Channels
[0079] The absorbent material deposition area 8 may comprise at
least one channel 26, which is at least partially oriented in the
longitudinal direction of the article 80 (i.e., has a longitudinal
vector component). Other channels may be at least partially
oriented in the lateral direction (i.e., has a lateral vector
component) or in any other direction. If the following, the plural
form "channels" will be used to mean "at least one channel". The
channels may have a length L' projected on the longitudinal axis 80
of the article that is at least 10% of the length L of the article.
The channels may be formed in various ways. For example, the
channels may be formed by zones within the absorbent material
deposition area 8 which may be substantially free of, or free of,
absorbent material, in particular SAP. In addition or
alternatively, the channel(s) may also be formed by continuously or
discontinuously bonding the top side of the core wrap to the bottom
side of the core wrap through the absorbent material deposition
area 8. The channels may be continuous but it is also envisioned
that the channels may be intermittent. The acquisition-distribution
system or layer 50, or another layer of the article, may also
comprise channels, which may or not correspond to the channels of
the absorbent core.
[0080] In some embodiments, the channels may be present at least at
the same longitudinal level as the crotch point C or the lateral
axis 60 in the absorbent article, as represented in FIG. 1 with the
two longitudinally extending channels 26, 26'. The channels may
also extend from the crotch region 7 or may be present in the front
waist region 5 and/or in the rear waist region 6 of the
article.
[0081] The absorbent core 28 may also comprise more than two
channels, for example, at least 3, at least 4, at least 5, or at
least 6 or more. Shorter channels may also be present, for example
in the rear waist region 6 or the front waist region 5 of the core
as represented by the pair of channels 27, 27' in FIG. 1 towards
the front of the article. The channels may comprise one or more
pairs of channels symmetrically arranged, or otherwise arranged
relative to the longitudinal axis 80.
[0082] The channels may be particularly useful in the absorbent
core when the absorbent material deposition area is rectangular, as
the channels may improve the flexibility of the core to an extent
that there is less advantage in using a non-rectangular (shaped)
core. Of course channels may also be present in a layer of SAP
having a shaped deposition area.
[0083] The channels may extend substantially longitudinally, which
means that each channel extends more in the longitudinal direction
than in the transverse direction, or at least twice as much in the
longitudinal direction than in the transverse direction (as
measured after projection on the respective axis). In other
embodiments, the channels may extend substantially laterally, which
means that each channel extends more in the lateral direction than
in the transverse direction, or at least twice as much in the
longitudinal direction than in the transverse direction (as
measured after projection on the respective axis).
[0084] The channels may be completely oriented longitudinally and
parallel to the longitudinal axis or completely oriented
transversely and parallel to the lateral axis, but also may be
curved. In various embodiments, some or all the channels, in
particular the channels present in the crotch region 7, may be
concave towards the longitudinal axis 80, as, for example,
represented in FIG. 1 for the pair of channels 26, 26'. The radius
of curvature may typically be at least equal (and may be at least
1.5 or at least 2.0 times this average transverse dimension) to the
average transverse dimension of the absorbent layer; and also
straight but under an angle of (e.g., from 5.degree.) up to
30.degree., up to 20.degree., up to 10.degree. with a line parallel
to the longitudinal axis. The radius of curvature may be constant
for a channel, or may vary along its length. This may also include
channels with an angle therein, provided the angle between two
parts of a channel is at least 120.degree., at least 150.degree.;
and in any of these cases, provided the longitudinal extension of
the channel is more than the transverse extension. The channels may
also be branched. For example, a central channel superposed with
the longitudinal axis in the crotch region 7 which branches towards
the rear waist edge 12 and/or towards the front waist edge 10 of
the article.
[0085] In some embodiments, there is no channel that coincides with
the longitudinal axis 80 of the article or the core. When present
as symmetrical pairs relative to the longitudinal axis 80, the
channels may be spaced apart from one another over their whole
longitudinal dimension. The smallest spacing distance may be at
least 5 mm, at least 10 mm, or at least 16 mm, for example.
[0086] Furthermore, in order to reduce the risk of fluid leakages,
the longitudinal main channels may not extend up to any of the
edges of the absorbent material deposition area 8, and may
therefore be fully encompassed within the absorbent material
deposition area 8 of the core. The smallest distance between a
channel and the closest edge of the absorbent material deposition
area 8 may be at least 5 mm.
[0087] The channels may have a width We along at least part of its
length which is at least 2 mm, at least 3 mm, at least 4 mm, up to
for example 20 mm, 16 mm, or 12 mm, for example. The width of the
channel may be constant through substantially the whole length of
the channel or may vary along its length. When the channels are
formed by absorbent material-free zone within the absorbent
material deposition area 8, the width of the channels is considered
to be the width of the material free zone, disregarding the
possible presence of the core wrap within the channels. If the
channels are not formed by absorbent material free zones, for
example mainly though bonding of the core wrap through the
absorbent material zone, the width of the channels if the width of
this bonding.
[0088] At least some or all of the channels may be permanent
channels, meaning their integrity is at least partially maintained
both in the dry state and in the wet state. Permanent channels may
be obtained by provision of one or more adhesive materials, for
example, the fibrous layer of adhesive material or construction
glue that helps adhere a substrate with an absorbent material
within the walls of the channel. Permanent channels may also be
formed by bonding the upper side and lower side of the core wrap
(e.g., the first substrate 16 and the second substrate 16') and/or
the topsheet 24 to the backsheet 25 together through the channels.
Typically, an adhesive may be used to bond both sides of the core
wrap or the topsheet and the a backsheet through the channels, but
it is possible to bond via other known processes, such as pressure
bonding, ultrasonic bonding, heat bonding, or combination thereof.
The core wrap or the topsheet 24 and the backsheet 25 may be
continuously bonded or intermittently bonded along the channels.
The channels may advantageously remain or become visible at least
through the topsheet and/or backsheet when the absorbent article is
fully loaded with a fluid. This may be obtained by making the
channels substantially free of SAP, so they will not swell, and
sufficiently large so that they will not close when wet.
Furthermore, bonding the core wrap to itself or the topsheet to the
backsheet through the channels may be advantageous.
[0089] FIG. 9 illustrates an example absorbent core 28 of the
present disclosure. This core 28, and the cores illustrated in
FIGS. 12 and 14-20, may be used in the absorbent articles of the
present disclosure and may have many or all of the features
discussed herein. In various embodiments, profiles of the sum of
the lateral widths of one or more channels (plotted on the Y-axis)
may be plotted relative to the longitudinal length about the
longitudinal axis 80' (plotted on the X-axis) of portions of the
one or more channels. Stated another way, the sum of the lateral
widths of the one or more channels over a particular a longitudinal
length about the longitudinal axis 80' of the one or more channels
may be plotted to create a profile.
[0090] To obtain data for such profiles, first, the absorbent
article or the absorbent core should be placed on a light table or
a light source suitable for viewing the channels within the
absorbent core. If the absorbent core is being used, it should
first be removed from the absorbent article using any suitable
techniques. The wearer-facing surface of the absorbent article or
the absorbent core should face away from the surface of the light
table. The absorbent article or the absorbent core should be
attached to the light illuminating surface of the light table or
light source using tape or other attachment members. Second, a
longitudinal length along the longitudinal axis 80 or 80' (e.g., 5
mm, 10 mm, 15 mm, 20 mm, 50 mm, 100 mm) should be selected for
measurement. A rigid or flexible tape measure, graduated in mm,
should be used to measure the longitudinal length along the
longitudinal axis 80 or 80'. A dot should be placed on the
absorbent article or the absorbent core at either end of the
longitudinal length on the longitudinal axis 80 or 80'. Next, a
line that is parallel to the lateral axis 90' should be drawn
through each dot. This enclosed area "EA" between the lines is the
area to be measured. The enclosed area "EA" can be a portion of the
absorbent article's or absorbent core's longitudinal length or the
entire length of the absorbent article or absorbent core from the
front waist edge 10 or front side 280 to the rear waist edge 12 or
rear side 282, respectively. In some instances, it may be desirable
to profile a large longitudinal length of the absorbent article or
absorbent core, while, in other instances, it may be desirable to
profile a small longitudinal length. Once the longitudinal length
to be used is indicated on the absorbent article or the absorbent
core, the sum of the lateral widths of the channels within the
enclosed area should be measured parallel to the lateral axis every
5 mm along the longitudinal length using the tape measure. If only
one channel is present at a particular 5 mm increment within the
enclosed area "EA" only one width will be the sum of the lateral
widths of the channel at that particular increment, while if more
than one channel is present at a particular 5 mm increment within
the enclosed area "EA", the sum of the lateral widths at that
increment will be the sum of those two or more lateral widths of
the channels. Those results should then be plotted to create a
profile or graph with the sum of the lateral widths of the one or
more channels being plotted on the Y-axis and the longitudinal
length along the longitudinal axis 80 or 80' at which they were
taken on the X-axis. The X-axis should be graduated in 5 mm
increments to correspond with lateral width measurements being
taken every 5 mm along the longitudinal axis 80 or 80'. The Y-axis
may be graduated in 1 mm increments, 2 mm increments, or greater
than 2 mm increments depending on the values of the sum of the
lateral widths of the one or more channels.
[0091] Referring to FIG. 9, as an example, the enclosed area "EA"
is between the two dashed lines at the end of the longitudinal
length L' of the one or more channels along the longitudinal axis
80'. For all absorbent core 28 embodiments, the longitudinal axis
80' corresponds with the longitudinal axis 80 of the absorbent
article and the lateral axis 90' corresponds with the lateral axis
90 of the absorbent article. Lateral width measurements of the
channels 26 and 26' are taken parallel to the lateral axis 90'
every 5 mm. Each 5 mm increment is indicated as a line "L" in FIG.
9. The first measurement is taken 5 mm into the enclosed area "EA"
from the top dashed line "TL". While FIG. 9 is not to scale, a
profile of the sum of the lateral widths taken in a direction
parallel to the lateral axis 90' every 5 mm along the longitudinal
axis 80' would look generally like the example profile of FIG. 10.
The longitudinal length along the longitudinal axis 80 is plotted
on the X-axis and the sum of the lateral widths is plotted on the
Y-axis. In this example, the sums of the laterals widths of the
channels within the enclosed area (every 5 mm) are all 10 mm (5 mm
per channel). Other sums of the lateral widths of the channels are
within the scope of the present disclosure. Example sums of the
lateral widths may be in the range of 5 mm to 120 mm, specifically
reciting all 1 mm increments within the specified range and any
ranges formed therein or thereby. The enclosed area may extend at
least 5 mm, at least 10 mm, at least 15 mm, at least 20 mm, at
least 30 mm, at least 40 mm, at least 50 mm, at least 60 mm, or at
least 70 mm, for example, along the longitudinal axis 90'. The
enclosed area may be smaller for sanitary napkins since their
absorbent cores are typically smaller than diapers. Thus, the
profile from FIG. 9 is constant, or substantially constant, since
the sum of the lateral widths of the channels 26 and 26' taken
every 5 mm along the longitudinal axis 80' should have the same
value. If only channel 26 were present in the enclosed area of FIG.
9, the profile would also be constant, or substantially constant,
since the lateral width of the channel 26 measured parallel to the
lateral axis 90' is constant, or substantially constant, in this
embodiment along the longitudinal length L'. The second channel 26'
may be positioned on the opposite side of the longitudinal axis 80'
as the first channel 26. The profile of the second channel 26' may
also be constant, or substantially constant, about a longitudinal
length, such as L' of FIG. 9, since the lateral width of the second
channel 26' is constant, or substantially constant, about the
channel's longitudinal length L'. In other embodiments, the lateral
widths of each channel 26 and 26' may be constant, substantially
constant, or variable along a longitudinal length or a portion
thereof. In other embodiments, one channel (e.g., channel 26) may
have a constant, or substantially constant, lateral width about its
longitudinal length, while the other channel (e.g., channel 26')
may have a varying lateral width about its longitudinal length. In
the embodiment of FIG. 9, the channel 26 and the channel 26' may
have the same longitudinal length along the longitudinal axis 80'.
In other embodiments, the first and second or more channels may
each have a different longitudinal length along the longitudinal
axis 80'.
[0092] The above is merely an example non-limiting configuration of
how to measure the sum of the lateral widths over a particular
longitudinal length along the longitudinal axis 80'. As discussed
below, other profiles are also within the scope of the present
disclosure based on the configurations and/or orientations of the
channels within the measured longitudinal length and/or enclosed
area.
[0093] Again referring to FIG. 9, a profile of the sum of the
lateral widths of the channels 26 and 26' over a portion of the
longitudinal length on a first side of the lateral axis 90' may be
different than a profile of the sum of the lateral widths of the
channels 26 and 26' over another portion of the longitudinal length
on a second side of the lateral axis 90'. In other embodiments, the
profile of the sum of the lateral widths of the channels 26 and 26'
over a portion of the longitudinal length on the first side of the
lateral axis 90' may be the same, or substantially the same, as the
profile of the sum of the lateral widths of the channels 26 and 26'
over a portion of the longitudinal length on the second side of the
lateral axis 90'
[0094] In an embodiment, referring to FIG. 1, the absorbent core 28
may comprise at least three channels or four channels (e.g., 26,
26', 27, 27'). These channels may be free of, or substantially
superabsorbent polymers and may be at least partially oriented in
the longitudinal direction and/or may be at least partially
oriented in the lateral direction. In various embodiments, the
longitudinal lengths of the channels 26 and 26' about the
longitudinal axis 80 may be the same, substantially the same (e.g.,
within 2 mm or less of each other), or different and the
longitudinal lengths of the channels 27 and 27' about the
longitudinal axis 80 may be the same, substantially the same, or
different. The longitudinal length of the channels 26 and 26' may
be larger than the longitudinal length of the channels 27 and 27'.
The average lateral width over the longitudinal lengths of the
channels 27 and 27' may be the same, substantially the same, or may
be different. Likewise, the average lateral width over the
longitudinal lengths of the channels 26 and 26' may be the same,
substantially the same, or may be different. The average lateral
width of any of the channels 26, 26', 27, and 27' may be the same,
substantially the same, or different. This rationale may apply to
any channel configurations disclosed herein.
[0095] In an embodiment, referring again to FIG. 1, at least two of
the three channels 26, 26', 27, and 27' may be at least partially
oriented in the longitudinal direction along of the longitudinal
axis 80 of the article. Each of the channels 26, 26', 27, and 27'
may have lateral widths taken parallel to the lateral axis 90.
Referring to FIG. 11, a profile of the sum of the lateral widths of
the channels over a longitudinal length along the longitudinal axis
80 of at least 5 mm, at least 10 mm, at least 15 mm, at least 20
mm, at least 25 mm, at least 30 mm, at least 35 mm, at least 40 mm,
at least 45 mm, at least 50 mm or greater taken along the
longitudinal axis 80 may have two maximum peaks "MP." The maximum
peaks may be separated from each other by a gap "G" extending at
least 1 mm, at least 3 mm, at least 5 mm, at least 10 mm, at least
15 mm, at least 20 mm or greater of the longitudinal length about
the longitudinal axis 80. An example of such a profile is
illustrated in FIG. 11. The profile of FIG. 11 was taken between
the longitudinal length represented by lines A and B every 5 mm in
longitudinal length (represented by dots along the first side edge
3). Lines parallel to the lateral axis 90 and intersecting each dot
should be drawn on the absorbent article. The sum of the lateral
width of the channels taken parallel to the lateral axis 90 should
be measured on each line using the tape measure. Although the
maximum peaks "MP" of FIG. 11 are illustrated separated by a 5 mm
gap "G", this gap could be less than 1 mm or greater than 1 mm, for
example, 1-15 mm or 1-9 mm.
[0096] Again referring to FIG. 11, the profile of the sum of the
lateral widths of the channels 26, 26', 27, and/or 27' over a
longitudinal length of at least 20 mm taken along the longitudinal
axis 80 may be bimodal and may have a portion between the two modes
where the sum of the lateral widths of at least three of the
channels 26, 26', 27, and 27' or all of the channels is zero. This
portion where the sum of the lateral widths of at least three of
the channels 26, 26', 27, and 27' or all of the channels is zero is
indicated by the gap G in FIG. 11.
[0097] In another embodiment, referring to FIG. 12, the absorbent
core 28 may comprise the first channel 26 and the second channel
26' as described above and one or more pockets 29 that are free of,
or substantially free of, the superabsorbent polymers. As an
example, the pocket 29 may have a width dimension of 20 mm to 110
mm or less or greater, such as 90 mm (about the lateral axis 90')
and a length dimension of 30 mm to 00 mm or less or greater, such
as 50 mm (about the longitudinal axis 80'). The one or more pockets
29 may have a portion positioned on the longitudinal axis 80' and
may be positioned in the front waist region 5, the rear waist
region 6, and/or the crotch region 7. In another embodiment, a
pocket may extend into two or more regions. Although FIGS. 9, 12
and 14-20 only show an absorbent core 28, it will be understood
that the front waist region 5, the rear waist region 6, and the
crotch region 7 will generally correspond with such regions on the
absorbent article as illustrated in FIG. 1. A portion of the one or
more pockets 29 may not be positioned on the longitudinal axis 80'.
In an embodiment, the one or more pockets 29 may have a portion
positioned on the lateral axis 90'. The pocket 29 has lateral
widths measured parallel to the lateral axis 90' and longitudinal
lengths measured parallel to the longitudinal axis 80'. A profile
of the sum of the lateral widths of the first and second channels
26 and 26' and the lateral widths of the pocket 29 over a
longitudinal length of 50 mm taken along the longitudinal axis 80'
may have two separate, constant, or substantially constant
portions, as illustrated in representative form in FIG. 13. FIG. 13
is the sum of the lateral widths of the superabsorbent polymer
free, or substantially superabsorbent polymer free, areas of the
channels 26 and 26' and the pocket 29 taken from line C to line D
in FIG. 12. The longitudinal length along the longitudinal axis 80'
between lines C and D may be at least 50 mm or less or more. As can
be seen from FIG. 13, the profile has two constant, or
substantially constant portions, representing the sum of the
lateral widths of the channels alone, and one portion larger than
the constant, or substantially constant portions, representing the
sum of the lateral widths of the channels 26 and 26' and the
lateral widths of the pocket 29. The sum of the lateral widths of
the first channel 26, the second channel 26', and the pocket 29 at
a point intermediate lines C and D may be in the range of about 20
mm to about 100 mm, for example. The lateral widths should be
measured every 5 mm along the longitudinal axis 80' as discussed
above and between lines C and D. The pocket 29 may be a bowel
movement "BM" pocket configured to retain BM. In another
embodiment, referring to FIG. 14, the pocket 29' may be positioned
at least partially in the front waist region 5 and may be a urine
management or retention pocket. In still another embodiment,
referring to FIG. 15, the pocket 29'' may be positioned at least
partially in the crotch region 7 and may be a urine management or
retention pocket and/or a BM pocket. The pocket 29'' may have
longitudinal side edges formed by the laterally inboard sides of
the channels 26 and 26' or may have longitudinal side edges formed
independently of the laterally inboard side edges of the channels
26 and 26'. The pockets 29, 29', or 29'' may have lateral widths
measured parallel to the lateral axis 90' every 5 mm along the
longitudinal axis 80' in the range of 10 mm to 110 mm, 20 mm to 100
mm, or 30 mm to 95 mm, specifically reciting all 1 mm increments
within the above-specified ranges and any ranges formed therein or
thereby.
[0098] In yet another embodiment, referring to FIG. 16, the
absorbent core 28 may comprise the first channel 26 and/or the
second channel 26' and a third channel 26'' (sometimes referred to
in the claims as a second channel if one of the first and second
channels 26 and 26' are not recited). The third channel 26'' may be
free of, or substantially free of, superabsorbent polymers and may
be positioned in the rear waist region 6, the crotch region 7,
and/or the front waist region 5. The third channel 26'' may be
positioned within 0-50 mm from the rear waist edge 12 or the rear
side 282 or within 0-50 mm from the front waist edge 10 or the
front side 280. All 1 mm increments within the above-specified
ranges are specifically recited herein including any ranges formed
therein or thereby. A sum of the lateral widths of the first
channel 26 and the third channel 26'' or the first channel 26, the
second channel 26', and the third channel 26'' at a point along the
longitudinal axis (for example, point E of FIG. 16) that is 50 mm,
or 30 mm, or 20 mm, or 15 mm, or 10 mm, or 5 mm, or 1 mm, or less
from the rear side 282 or the rear waist edge 12 or the front side
280 or front waist edge 10 may be greater than zero. FIG. 17
illustrates an absorbent core 28 comprising a first channel 26, a
second channel 26', a third channel 31, and a fourth channel 31'.
Any of these channels may be optional. The sum of the lateral
widths of the third channel 31 and the fourth channel 31' at a
point along the longitudinal axis 80' (for example, point F of FIG.
17) that is 50 mm, or 30 mm, or 20 mm, or 15 mm, or 10 mm, or 5 mm,
or 3 mm, or 1 mm, or less from the rear waist edge 12, the rear
side 282, the front waist edge 10, or the front side 280 may be
greater than zero.
[0099] In an embodiment, referring to FIG. 18, the first channel 26
and the second channel 26' may each have a first arcuate portion 33
in the front waist region 5 and a second arcuate portion 33' in the
rear waist region 6. The arcuate portions 33 and 33' may face the
longitudinal axis 80'. The first channel 26 and the second channel
26' may also have a third arcuate portion 33'' in the crotch region
7 or a non-arcuate portion in 33'' the crotch region 7. The arcuate
portions 33'' or the portions 33'' may also face the longitudinal
axis 80'. Tangent lines 35 of the arcuate portions 33 may intersect
the longitudinal axis 80' to create angle A1. The angle of
intersection A1 between the tangent lines 35 and the longitudinal
axis 80' may be in the range of 10 degrees to 80 degrees, 20
degrees to 75 degrees, 30 degrees to 60 degrees, or 45 degrees.
Tangent lines 35' of the arcuate portions 33' may intersect the
longitudinal axis 80' to create angle A2. The angle of intersection
A2 between the tangent lines 35' and the longitudinal axis 80' may
be in the range of 10 degrees to 80 degrees, 20 degrees to 75
degrees, 30 degrees to 60 degrees, or 45 degrees. Tangent lines
35'' of the arcuate portions 33'' may intersect the longitudinal
axis 80' to create angle A3. The angle of intersection A3 between
the tangent lines 35'' and the longitudinal axis 80' may be in the
range of 0.1 degrees to 35 degrees or 1 degree to 20 degrees. In an
embodiment, tangent lines may extend from the non-arcuate portions
33'' in the crotch region 7. The tangent lines may not intersect
the longitudinal axis 80' and may instead extend in directions
parallel to the longitudinal axis 80'. All 0.5 degree increments
within the ranges specified in this paragraph are recited herein
including any ranges formed therein or thereby.
[0100] As can be seen in FIG. 18, the first tangent line 35 taken
from the first arcuate portion 33 on a first side of the
longitudinal axis 80' may have a positive slope (rise/run) and the
first tangent line 35 taken from the first arcuate portion 33 on
the second side of the longitudinal axis 80' may have a negative
slope. The second tangent line 35' taken from the second arcuate
portion 33' on a first side of the longitudinal axis 80' may have a
negative slope and the second tangent line 35' taken from the
second arcuate portion 33'on the second side of the longitudinal
axis 80' may have a positive slope. The tangent lines 35'' may also
have a positive or a negative slope. The slopes of the various
tangent lines may be different if the configuration of the channels
is different.
[0101] Again referring to FIG. 18, angles A1, A2, and A3 on a first
side of the longitudinal axis 80' may be different than, the same
as, or substantially the same as angles A1, A2, and A3,
respectively, on a second side of the longitudinal axis 80'. In an
embodiment, with respect to angles on one side of the longitudinal
axis 80', angle A1 may be greater than angles A2 and A3 and angle
A2 may be greater than angle A3. In other embodiments, with respect
to angles on one side of the longitudinal axis 80', angle A1 and
angle A2 may be the same or substantially the same, while angle A3
may be less than angles A1 and A2. In still other embodiments, any
of the angles on one side of the longitudinal axis 80' may be the
same or different.
[0102] The tangent lines 35 are taken from portions of the arcuate
portions 33 in the front waist region 5. The tangent lines 35' are
taken from portions of the arcuate portions 33' in the rear waist
region 6. The tangent lines 35'' are taken from portions of the
arcuate portions 33'' in the crotch region 7.
[0103] The longitudinal axis 80 or 80' can be drawn on an absorbent
article or the absorbent core, respectively, by connecting the
midpoints of the first waist edge 10 or first side 280 and the
second waist edge 12 or second side 282, respectively. The tangent
lines can be drawn on the absorbent article or the absorbent core
using a straight edge. Multiple tangent lines may be drawn on an
arcuate portion in the front waist region 5, the rear waist region
6, and/or the crotch region 7. The tangent lines should be drawn
long enough to intersect the longitudinal axis 80 or 80' unless
they are positioned parallel to the longitudinal axis 80 or 80'. A
protractor, graduated in 1 degree increments, may then be used to
measure the angles (A1, A2, and A3) between the tangent lines and
the longitudinal axis 80 or 80'. If additional channels are present
in the absorbent core 28, additional tangent lines may be drawn on
those channels in the same or a similar fashion.
[0104] In an embodiment, referring to FIG. 19, in additional to the
first and second channels 26 and 26' discussed above, an absorbent
core may comprise a channel or pocket 37 that is free of, or
substantially free of, superabsorbent polymers. A portion of the
channel or pocket 37 may be located on the longitudinal axis 80'.
The channel or pocket 37 may comprise an arcuate portion 39 facing
the side 284 or the second side edge 4 and another arcuate portion
39' facing the side 282 or the first side edge 3. An angle, A4,
between a tangent line 41' (or 41) of the arcuate portion 39' (or
39) and the longitudinal axis 80' may be in the range of about 0.1
degrees to 40 degrees, 0.1 degrees to 20 degrees, 0.1 degrees to 15
degrees, 0.1 degrees to 10 degrees, or 0.1 degrees to five degrees,
specifically reciting all 0.1 degree increments within the
above-specified ranges and any ranges formed therein or thereby. In
an embodiment, the tangent line 41 (or 41') may extend parallel to
the longitudinal axis 80' and never intersect the longitudinal axis
80'. The channel or pocket 37 may be positioned at least partially
within the front waist region 5, the rear waist region 6, and/or
the crotch region 7.
[0105] In an embodiment, referring to FIG. 20, in addition to the
first and second channels 26 and 26', an absorbent core 28 may
comprise a channel or a pocket 43 having a portion positioned on
the longitudinal axis 80'. The channel or pocket 43 may have a
longitudinal length in the range of 10 mm to 150 mm and a lateral
width of 10 mm to about 150 mm, specifically reciting all 1 mm
increments within the specified ranges and all ranges formed
therein or thereby. Other dimensions are also within the scope of
the present disclosure. The channel or the pocket 43 may be located
in the front waist region 5 or the rear waist region 6, or both.
The channel or pocket 43 may have an arcuate portion 45 facing the
front side 280 or the front waist edge 10 if the channel or pocket
43 is located in the front waist region 5 and an arcuate portion 45
facing the rear side 282 or the rear waist region 12 if the channel
or pocket 43 is located in the rear waist region 6. The channel or
pocket 43 may extend into the crotch region 7 in some instances. A
tangent line 47 of the arcuate portion 45 may create an angle with
the longitudinal axis 80' in the range of 70 degrees to 110
degrees, 80 degrees to 100 degrees, 85 degrees to 85 degrees, about
90 degrees, or 90 degrees, specifically reciting all 0.5 degree
increments within the specified ranges and any ranges formed
therein or thereby.
[0106] In an embodiment, referring to FIG. 21, in addition to the
first and second channels 26 and 26', an absorbent core 28 may
comprise a pocket 53 in the crotch region 7 and/or the rear waist
region 6 and one or more channels 55 in the rear waist region 6
and/or the crotch region 7. In another embodiment, the pocket 53
may be in the crotch region 7 and/or the front waist region 5 and
the one or more channels 55 may be in the crotch region 7 and/or
the front waist region 5. The pocket 53 and the one or more
channels 55 may be BM pockets or channels and/or urine management
pockets and/or channels. The channels 55 may extend generally in
the lateral direction about the lateral axis 90'. The various
parameters discussed herein may apply to FIG. 21, if suitable. For
instance, at least one, or all of, the channels 55 may have a
tangent line 59 extending from an arcuate portion 57 thereof The
angle formed between the tangent line 59 and the longitudinal axis
80' may be 80 degrees to 100 degrees, about 90 degrees, or 90
degrees, for example.
Barrier Leg Cuffs
[0107] The absorbent article may comprise a pair of barrier leg
cuffs 34. Each barrier leg cuff may be formed by a piece of
material which is bonded to the article so it can extend upwards
from the inner surface of the article and provide improved
containment of liquids and other body exudates approximately at the
junction of the torso and legs of the wearer. The barrier leg cuffs
are delimited by a proximal edge 64 joined directly or indirectly
to the topsheet 24 and/or the backsheet 25 and a free terminal edge
66, which is intended to contact and form a seal with the wearer's
skin. The barrier leg cuffs extend at least partially between the
front waist edge 10 and the rear waist edge 12 of the absorbent
article on opposite sides of the longitudinal axis 80 and are at
least present at the level of the crotch point (C) or crotch
region. The barrier leg cuffs may be joined at the proximal edge 64
with the chassis of the article by a bond 65 which may be made by
gluing, fusion bonding, or combination of other suitable bonding
processes. The bond 65 at the proximal edge 64 may be continuous or
intermittent. The bond 65 closest to the raised section of the leg
cuffs delimits the proximal edge 64 of the standing up section of
the leg cuffs.
[0108] The barrier leg cuffs may be integral with the topsheet 24
or the backsheet 25 or may be a separate material joined to the
article's chassis. The material of the barrier leg cuffs may extend
through the whole length of the diapers but may be "tack bonded" to
the topsheet 24 towards the front waist edge 10 and rear waist edge
12 of the article so that in these sections the barrier leg cuff
material remains flush with the topsheet 24.
[0109] Each barrier leg cuff 34 may comprise one, two or more
elastic strings 35 close to this free terminal edge 66 to provide a
better seal.
[0110] In addition to the barrier leg cuffs 34, the article may
comprise gasketing cuffs 32, which are joined to the chassis of the
absorbent article, in particular to the topsheet 24 and/or the
backsheet 25 and are placed externally relative to the barrier leg
cuffs. The gasketing cuffs 32 may provide a better seal around the
thighs of the wearer. Each gasketing leg cuff may comprise one or
more elastic strings or elastic elements in the chassis of the
absorbent article between the topsheet 24 and backsheet 25 in the
area of the leg openings.
[0111] U.S. Pat. No. 3,860,003 describes a disposable diaper which
provides a contractible leg opening having a side flap and one or
more elastic members to provide an elasticized leg cuff (a
gasketing cuff). U.S. Pat. No. 4,808,178 and U.S. Pat. No.
4,909,803 issued to Aziz et al. describes disposable diapers having
"stand-up" elasticized flaps (barrier leg cuffs) which improve the
containment of the leg regions. U.S. Pat. No. 4,695,278 and U.S.
Pat. No. 4,795,454 issued to Lawson and to Dragoo respectively,
describe disposable diapers having dual cuffs, including gasketing
cuffs and barrier leg cuffs. All or a portion of the barrier leg
and/or gasketing cuffs may be treated with a lotion.
Acquisition-Distribution System
[0112] The absorbent articles of the present disclosure may
comprise an acquisition-distribution layer or system 50 (herein
"ADS"). One function of the ADS is to quickly acquire the fluid and
distribute it to the absorbent core in an efficient manner. The ADS
may comprise one, two or more layers, which may form a unitary
layer or may remain as discrete layers which may be attached to
each other. In an embodiment, the ADS may comprise two layers: a
distribution layer 54 and an acquisition layer 52 disposed between
the absorbent core and the topsheet, but the present disclosure is
not limited to this embodiment.
[0113] The ADS may comprise SAP as this may slow the acquisition
and distribution of the fluid. Suitable ADS are described in WO
2000/59430 (Daley), WO 95/10996 (Richards), U.S. Pat. No. 5,700,254
(McDowall), and WO 02/067809 (Graef), for example.
Distribution Layer
[0114] The distribution layer of the ADS may comprise at least 50%
by weight of cross-linked cellulose fibers. The cross-linked
cellulosic fibers may be crimped, twisted, or curled, or a
combination thereof including crimped, twisted, and curled. This
type of material is disclosed in U.S. Pat. Publ. No. 2008/0312622
A1 (Hundorf). The cross-linked cellulosic fibers provide higher
resilience and therefore higher resistance to the first absorbent
layer against the compression in the product packaging or in use
conditions, e.g., under baby weight. This provides the core with a
higher void volume, permeability, and liquid absorption, and hence
reduced leakage and improved dryness.
[0115] Example chemically cross-linked cellulosic fibers suitable
for a distribution layer are disclosed in U.S. Pat. No. 5,549,791,
U.S. Pat. No. 5,137,537, WO 9534329, or U.S. Pat. Publ. No.
2007/118087. Example cross-linking agents include polycarboxylic
acids such as citric acid and/or polyacrylic acids such as acrylic
acid and maleic acid copolymers.
[0116] The distribution layer comprising cross-linked cellulose
fibers of the present disclosure may comprise other fibers, but
this layer may advantageously comprise at least 50%, or 60%, or
70%, or 80%, or 90%, or even up to 100%, by weight of the layer, of
cross-linked cellulose fibers (including the cross-linking agents).
Examples of such mixed layer of cross-linked cellulose fibers may
comprise about 70% by weight of chemically cross-linked cellulose
fibers, about 10% by weight polyester (PET) fibers, and about 20%
by weight untreated pulp fibers. In another example, the layer of
cross-linked cellulose fibers may comprise about 70% by weight
chemically cross-linked cellulose fibers, about 20% by weight
lyocell fibers, and about 10% by weight PET fibers. In another
example, the layer may comprise about 68% by weight chemically
cross-linked cellulose fibers, about 16% by weight untreated pulp
fibers, and about 16% by weight PET fibers. In another example, the
layer of cross-linked cellulose fibers may comprise from about
90-100% by weight chemically cross-linked cellulose fibers.
[0117] The distribution layer 54 may be a material having a water
retention value of from 25 to 60 or from 30 to 45, measured as
indicated in the procedure disclosed in U.S. Pat. No.
5,137,537.
[0118] The distribution layer may typically have an average basis
weight of from 30 to 400 g/m.sup.2 or from 100 to 300 g/m.sup.2,
specifically reciting all 1.0 g/m.sup.2 increments within the
above-specified ranges and any ranges formed therein or thereby.
The density of the distribution layer may vary depending on the
compression of the article, but may be between 0.03 to 0.15
g/cm.sup.3 or 0.08 to 0.10 g/cm.sup.3, specifically reciting all
1.0 g/cm.sup.3 increments within the above-specified ranges and any
ranges formed therein or thereby, measured at 0.30 psi (2.07
kPa).
Acquisition Layer
[0119] The ADS may comprise an acquisition layer 52. The
acquisition layer may be disposed between the distribution layer 54
and the topsheet 24. The acquisition layer 52 may be or may
comprise a non-woven material, such as an SMS or SMMS material,
comprising a spunbonded, a melt-blown and a further spunbonded
layer or alternatively a carded chemical-bonded nonwoven. The
nonwoven material may be latex bonded. Example upper acquisition
layers 52 are disclosed in U.S. Pat. No. 7,786,341. Carded,
resin-bonded nonwovens may be used, in particular where the fibers
used are solid round or round hollow PET staple fibers (50/50 or
40/60 mix of 6 denier and 9 denier fibers). An example binder is a
butadiene/styrene latex. Nonwovens have the advantage that they can
be manufactured outside the converting line and stored and used as
a roll of material.
[0120] The acquisition layer 52 may be stabilized by a latex
binder, for example a styrene-butadiene latex binder (SB
latex).
[0121] A further acquisition layer may be used in addition to a
first acquisition layer described above. For example, a tissue
layer may be placed between the first acquisition layer and the
distribution layer. The tissue may have enhanced capillarity
distribution properties compared to the acquisition layer described
above. The tissue and the first acquisition layer may be of the
same size or may be of a different size. For example, the tissue
layer may extend further in the rear of the absorbent article than
the first acquisition layer. An example of hydrophilic tissue is a
13-15 gsm high wet strength made of cellulose fibers from supplier
Havix.
Fastening System
[0122] The absorbent article may include a fastening system. The
fastening system may be used to provide lateral tensions about the
circumference of the absorbent article to hold the absorbent
article on the wearer as is typical for taped diapers. This
fastening system may not be necessary for training pant articles
since the waist region of these articles is already bonded. The
fastening system may comprise a fastener such as tape tabs, hook
and loop fastening components, interlocking fasteners such as tabs
& slots, buckles, buttons, snaps, and/or hermaphroditic
fastening components, although any other suitable fastening
mechanisms are also within the scope of the present disclosure. A
landing zone 44 is normally provided on the garment-facing surface
of the front waist region 5 for the fastener to be releasably
attached thereto. Some example surface fastening systems are
disclosed in U.S. Pat. No. 3,848,594, U.S. Pat. No. 4,662,875, U.S.
Pat. No. 4,846,815, U.S. Pat. No. 4,894,060, U.S. Pat. No.
4,946,527, U.S. Pat. No. 5,151,092, and U.S. Pat. No. 5,221,274. An
example interlocking fastening system is disclosed in U.S. Pat. No.
6,432,098. The fastening system may also provide a mechanism for
holding the article in a disposal configuration as disclosed in
U.S. Pat. No. 4,963,140 issued to Robertson et al.
[0123] The fastening system may also include primary and secondary
fastening systems, as disclosed in U.S. Pat. No. 4,699,622 to
reduce shifting of overlapped portions or to improve fit as
disclosed in U.S. Pat. No. 5,242,436, U.S. Pat. No. 5,499,978, U.S.
Pat. No. 5,507,736, and U.S. Pat. No. 5,591,152.
Front and Rear Ears
[0124] In an embodiment, the absorbent article may comprise front
ears 46 and rear ears 40. The ears may be an integral part of the
chassis, such as formed from the topsheet 24 and/or backsheet 26 as
side panel. Alternatively, as represented on FIG. 1, the ears may
be separate elements attached by gluing, heat embossing, and/or
pressure bonding. The rear ears 40 may be stretchable to facilitate
the attachment of the tabs 42 to the landing zone 44 and maintain
the taped diapers in place around the wearer's waist. The rear ears
40 may also be elastic or extensible to provide a more comfortable
and contouring fit by initially conformably fitting the absorbent
article to the wearer and sustaining this fit throughout the time
of wear well past when absorbent article has been loaded with
exudates since the elasticized ears allow the sides of the
absorbent article to expand and contract.
Elastic Waist Feature
[0125] The absorbent article may also comprise at least one elastic
waist feature (not represented) that helps to provide improved fit
and containment. The elastic waist feature is generally intended to
elastically expand and contract to dynamically fit the wearer's
waist. The elastic waist feature may extend at least longitudinally
outwardly from at least one waist edge of the absorbent core 28 and
generally forms at least a portion of the end edge of the absorbent
article. Disposable diapers may be constructed so as to have two
elastic waist features, one positioned in the front waist region
and one positioned in the rear waist region. The elastic waist
feature may be constructed in a number of different configurations
including those described in U.S. Pat. No. 4,515,595, U.S. Pat. No.
4,710,189, U.S. Pat. No. 5,151,092, and U.S. Pat. No.
5,221,274.
Relations Between the Layers
[0126] Typically, adjacent layers and components may be joined
together using conventional bonding methods, such as adhesive
coating via slot coating or spraying on the whole or part of the
surface of the layer, thermo-bonding, pressure bonding, or
combinations thereof This bonding is not represented in the Figures
(except for the bonding between the raised element of the leg cuffs
65 with the topsheet 24) for clarity and readability, but bonding
between the layers of the article should be considered to be
present unless specifically excluded. Adhesives may be used to
improve the adhesion of the different layers between the backsheet
25 and the core wrap. The glue may be any suitable hotmelt glue
known in the art.
[0127] If an acquisition layer 52 is present, it may be desired
that this acquisition layer is larger than or least as large as the
distribution layer 54 in the longitudinal and/or transversal
dimension. Thus, the distribution layer 52 may be deposited on the
acquisition layer. This simplifies handling, in particular if the
acquisition layer is a nonwoven which may be unrolled from a roll
of stock material. The distribution layer may also be deposited
directly on the absorbent core's upper side of the core wrap or
another layer of the article. Also, having an acquisition layer 52
that is larger than the distribution layer allows for direct gluing
of the acquisition layer to the storage core (at the larger areas).
This may provide increased patch integrity and better liquid
communication.
[0128] The absorbent core and in particular its absorbent material
deposition area 8 may be at least as large and long and at least
partially larger and/or longer than the acquisition-distribution
system (ADS). This is because the absorbent material in the core
may more effectively retain fluid and provide dryness benefits
across a larger area than the ADS. The absorbent article may have a
rectangular SAP layer and a non-rectangular (shaped) ADS. The
absorbent article may also have a rectangular (non-shaped) ADS and
a rectangular layer of SAP.
Sanitary Napkin Features
[0129] In an embodiment, referring to FIG. 22, the absorbent
article may be a sanitary napkin 3010. The sanitary napkin 3010 may
comprise a liquid permeable topsheet 3014, a liquid impermeable, or
substantially liquid impermeable, backsheet 3016, and an absorbent
core 3018. The absorbent core 3018 may have any or all of the
features described herein with respect to the absorbent cores 28
and, in some embodiments, may have a secondary topsheet instead of
the acquisition-distribution system disclosed above. The sanitary
napkin 3010 may also comprise wings 3020 extending outwardly with
respect to a longitudinal axis 3080 of the sanitary napkin 3010.
The sanitary napkin 3010 may also comprise a lateral axis 3090. The
wings 3020 may be joined to the topsheet 3014, the backsheet 3016,
and/or the absorbent core 3018. The sanitary napkin 3010 may also
comprise a front edge 3022, a rear edge 3024 longitudinally
opposing the front edge 3022, a first side edge 3026, and a second
side edge 3028 longitudinally opposing the first side edge 3026.
The longitudinal axis 3080 may extend from a midpoint of the front
edge 3022 to a midpoint of the rear edge 3024. The lateral axis
3090 may extend from a midpoint of the first side edge 3028 to a
midpoint of the second side edge 3028. The sanitary napkin 3010 may
also be provided with additional features commonly found in
sanitary napkins as is known in the art.
Method of Making the Article
[0130] The absorbent articles and sanitary napkins of the present
disclosure may be made by any suitable methods known in the art. In
particular, the articles may be hand-made or industrially produced
at high speed.
[0131] 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."
[0132] Every document cited herein, including any cross referenced
or related patent or application, is hereby incorporated herein by
reference in its entirety unless expressly excluded or otherwise
limited. The citation of any document is not an admission that it
is prior art with respect to any embodiment disclosed or claimed
herein or that it alone, or in any combination with any other
reference or references, teaches, suggests or discloses any such
embodiment. Further, to the extent that any meaning or definition
of a term in this document conflicts with any meaning or definition
of the same term in a document incorporated by reference, the
meaning or definition assigned to that term in this document shall
govern.
[0133] While particular embodiments of the present disclosure have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications may
be made without departing from the spirit and scope of the present
disclosure. It is therefore intended to cover in the appended
claims all such changes and modifications that are within the scope
of this disclosure.
* * * * *