U.S. patent application number 12/841467 was filed with the patent office on 2012-01-26 for flexible reusable outer covers for disposable absorbent inserts.
Invention is credited to Donald Carroll Roe.
Application Number | 20120022491 12/841467 |
Document ID | / |
Family ID | 44629659 |
Filed Date | 2012-01-26 |
United States Patent
Application |
20120022491 |
Kind Code |
A1 |
Roe; Donald Carroll |
January 26, 2012 |
Flexible Reusable Outer Covers For Disposable Absorbent Inserts
Abstract
Flexible reusable outer covers for disposable absorbent
inserts.
Inventors: |
Roe; Donald Carroll; (West
Chester, OH) |
Family ID: |
44629659 |
Appl. No.: |
12/841467 |
Filed: |
July 22, 2010 |
Current U.S.
Class: |
604/394 |
Current CPC
Class: |
A61F 13/515 20130101;
A61F 13/505 20130101; A61F 13/51456 20130101; A61F 2013/5055
20130101; A61F 13/15268 20130101; A61F 13/49004 20130101 |
Class at
Publication: |
604/394 |
International
Class: |
A61F 13/505 20060101
A61F013/505 |
Claims
1. A reusable outer cover, configured for use with a disposable
absorbent insert as a wearable absorbent article, wherein: the
reusable outer cover has a bending stiffness peak force, measured
according to the Bending Stiffness Test; and the bending stiffness
peak force of the reusable outer cover is less than or equal to
0.20 Newtons.
2. The reusable outer cover of claim 1, wherein the bending
stiffness peak force of the reusable outer cover is less than or
equal to 0.18 Newtons.
3. The reusable outer cover of claim 1, wherein the bending
stiffness peak force of the reusable outer cover is less than or
equal to 0.15 Newtons.
4. The reusable outer cover of claim 1, including a plurality of
layers.
5. The reusable outer cover of claim 4, wherein each of the layers
has a bending stiffness peak force, measured according to the
Bending Stiffness Test, and the bending stiffness peak force of
each of the layers is less than or equal to 0.10 Newtons.
6. The reusable outer cover of claim 4, wherein each of the layers
has a bending stiffness peak force, measured according to the
Bending Stiffness Test, and the bending stiffness peak force of
each of the layers is less than or equal to 0.08 Newtons.
7. The reusable outer cover of claim 1, including an outer layer
material and an inner liner material.
8. An absorbent article, comprising the reusable outer cover of
claim 1 and a disposable absorbent insert.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to the field of
diapers and more particularly, to flexible reusable outer covers
for disposable absorbent inserts.
BACKGROUND OF THE INVENTION
[0002] Several designs of diapers that include a reusable outer
cover been manufactured and marketed. However, these designs have
less flexible reusable outer covers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 is a perspective view of a wearable absorbent article
as it might appear being worn by a wearer about the lower
torso;
[0004] FIG. 2A is a plan view of an outer cover opened and laid
flat, outer surface facing the viewer;
[0005] FIG. 2B is a plan view of an outer cover opened and laid
flat, inner surface facing the viewer;
[0006] FIG. 3 is a perspective view of a disposable absorbent
insert shown apart from an outer cover, as it might appear in a
free-standing, relaxed state;
[0007] FIG. 4 is a plan view of a disposable absorbent insert shown
stretched out and laid flat, body-facing surfaces facing the
viewer;
[0008] FIG. 5 is a front view of a plunger blade used for the upper
movable test fixture in the Bending Stiffness Test;
[0009] FIG. 6 is a side view of a plunger blade used for the upper
movable test fixture in the Bending Stiffness Test;
[0010] FIG. 7 is a side view of a lower stationary test fixture in
the Bending Stiffness Test.
DETAILED DESCRIPTION OF THE INVENTION
[0011] Definitions
[0012] For purposes of this description, the following terms have
the meanings set forth:
[0013] "Absorbent insert" and "insert" mean a component of a
wearable absorbent article that is adapted to contain and/or absorb
urine, feces, menses or any combination thereof, and is adapted to
be installable and removable as a modular unit, from an outer
cover. Herein, an absorbent insert may also be referred to as an
"absorbent assembly". The terms "absorbent insert," "insert" and
"absorbent assembly" may be used interchangeably herein.
[0014] "Chassis" means a component of a wearable absorbent article
that is adapted to be worn about the lower torso of a wearer, and
is adapted to support an absorbent insert and hold the insert next
to the wearer's body. Herein, a chassis may also be referred to as
an "outer cover". The terms "outer cover" and "chassis" are
interchangeable for purposes herein.
[0015] "Disposable", when referring to an absorbent insert, means
that the absorbent insert is not adapted or intended to be
effectively sanitarily laundered in an ordinary household
laundering process and ordinary household equipment, and thereby is
ordinarily unsuitable for sanitary and effective reuse so as to
provide as-new intended functions and performance, following
soiling by exudates and removal from an outer cover. By way of
non-limiting examples, effective laundering may be frustrated or
prevented, causing the insert to be disposable, by inclusion of
materials and/or construction: that do not retain their substantial
as-new physical shape or structure through ordinary household
laundering and drying so as to be effective as-new in reuse; that
absorb aqueous liquids and cannot be sufficiently dried/dehydrated
in ordinary household drying equipment and ordinary drying cycles
so as to be effective as-new in reuse; that dissolve or
substantially degrade in ordinary household laundering or drying,
causing the insert to be substantially damaged or rendered useless;
and/or that cannot be effectively cleaned of exudate material
through ordinary laundering, so as to be sanitary and otherwise
acceptable for re-use.
[0016] "Fastener component" means any component of a system that
effects removable fastening, attachment or holding of a first
structure to a second structure. The system may have a single
fastener component, for example, an adhesive patch on the first
structure adapted to adhere to one or more types of surfaces on the
second structure, or a hook, or patch of hooks on the first
structure, adapted to catch on one or more types of surfaces on the
second structure. By way of further example, any structure such as
a pocket, strap, hook, buckle, etc. on a first structure adapted to
capture and retain, in whole or in part, the second structure, is a
"fastener component" as used herein. The system also may comprise
two or more fastener components, for example, respective components
of a hook-and-loop fastening system (such as VELCRO), respective
surfaces having a cohesive material applied thereto; male and
female snap fastener components, a button and button hole, slot or
loop, other fastenably cooperating elements, etc. Other examples of
fastener components include zipper components, "zip lock" engaging
components, loops, posts, pockets, bands or straps, microfasteners,
macrofasteners, and fastener components such as described in U.S.
Pat. Nos. 6,936,039; 6,893,388; 6,669,618; 6,432,098; and
6,251,097, and U.S. Published Applications, Pub. Nos. 2005/0234419;
2005/0215971; 2005/0215970; 2005/0130821; 2004/0023771;
2003/0233082; 2003/0119641; 2003/0088220; and 2002/0169431.
[0017] "Lateral" (and forms thereof), with respect to a wearer,
means along a direction generally transverse or across the
direction extending from the front to the rear of the wearer, or
vice versa. With respect to a component of a wearable absorbent
article, "lateral" (and forms thereof), means along a direction
generally transverse or across the direction extending along the
component as it would be properly situated on a wearer, from the
front to the rear of the wearer, or vice versa.
[0018] "Longitudinal" (and forms thereof), with respect to a
wearer, means along a direction generally extending from the front
to the rear of the wearer, or vice versa. With respect to a
component of a wearable absorbent article, "longitudinal" (and
forms thereof), means along a direction generally extending along
the component as it would be properly situated on a wearer, from
the front to the rear of the wearer, or vice versa.
[0019] "Outer cover" means a component of a wearable absorbent
article that is adapted to be worn about the lower torso of a
wearer, and is adapted to support an absorbent insert and hold the
insert next to the wearer's body. Herein, an outer cover may also
be referred to as a "chassis". The terms "outer cover" and
"chassis" are interchangeable for purposes herein.
[0020] "Reusable", when referring to an outer cover, means an outer
cover that is adapted to permit removal of at least a first insert,
and replacement thereof with at least a second insert, without
substantial destruction of any components of the outer cover that
are necessary to provide the substantial as-new functionality of
the outer cover, and without the necessity of any repair or
reconstruction following such insert replacement.
[0021] "Use," with respect to an outer cover, means one event of
the wearing of the outer cover until the time an absorbent insert
is replaced.
[0022] "User" means a caregiver or other person who may apply a
wearable absorbent article to a wearer. Where the wearer is capable
of donning the wearable absorbent article him/herself, the wearer
is also a "user".
[0023] "Wearer" means a person who may wear a wearable absorbent
article as described herein.
[0024] "Wearable absorbent article" means any article designed to
be worn about the lower torso and to contain and/or absorb urine,
feces, menses or any combination thereof. "Wearable absorbent
article" includes but is not limited to baby or children's diapers
(of the "tape"-fastenable, otherwise fastenable, "pull-up" or any
other variety), training pants and adult incontinence pants, briefs
and the like.
[0025] Two-Piece Wearable Absorbent Articles
[0026] FIG. 1 depicts an example of a wearable absorbent article 10
having certain features, as it might appear while being worn by a
wearer. Wearable absorbent article 10 may include an outer cover
20, having front waist edge 21, rear waist edge 22, and a pair of
leg opening edges 23.
[0027] FIGS. 2A and 2B depict an outer cover 20 as it may appear
opened and laid flat. In FIG. 2A, the outer, i.e., garment-facing,
surfaces of outer cover 20 face the viewer; in FIG. 2B, the inner,
i.e., wearer-facing, surfaces of outer cover 20 face the viewer.
Front and rear waist edges 21, 22 are depicted at the top and
bottom of the drawings, respectively. Outer cover 20 may have
crotch region 26, front region 27, rear region 28 and a pair of
fastening ears 29 laterally extending from rear region 28. Outer
cover 20 will have a length LC from the forwardmost portion of
front waist edge 21 to the rearwardmost portion of rear waist edge
22, and an outer cover lateral axis 45 equally dividing this
length. Thus, front region 27 is forward of outer cover lateral
axis 45, and rear region 28 is rearward of outer cover lateral axis
45. Outer cover 20 may have disposed thereon one or more insert
fastener components such as front and rear insert fastener
components 33, 32.
[0028] FIG. 3 depicts a disposable absorbent insert 50 that may
form an inner component of the wearable absorbent article 10, shown
in perspective view as it might appear in a free-standing, relaxed
state, apart from outer cover 20. Insert 50 may be designed to
contain and/or absorb body exudates, and may be made of pliable
materials as will be described further below. Insert 10 has forward
region 54 and rearward region 55, and may include front fastener
component 56 and rear fastener component 57. Insert 10 may include
a body-facing liner or topsheet 51, outer liner or backsheet 52,
and a pair of standing cuffs 53. Referring to FIG. 4, insert 50
will have a length L from the forwardmost portion of forward region
54 to the rearwardmost portion of rearward region 55, and an insert
lateral axis 70 equally dividing this length. Thus, forward region
54 is forward of insert lateral axis 70, and rearward region 55 is
rearward of insert lateral axis 70.
[0029] Referring to FIGS. 2B and 3, insert 50 may have rear
fastener component 57 disposed thereon. Alternatively, or in
addition, outer cover 20 may have rear insert fastener component 32
disposed thereon. Similarly, insert 50 may have front fastener
component 56 disposed thereon. Alternatively, or in addition, outer
cover 20 may have front insert fastener component 32 disposed
thereon. If a two-component fastening system is used, fastener
component pairs 57, 32 and 56, 33 may be cooperating components
that effect fastening therebetween when these respective components
are brought together. Thus, in the example depicted, in order to
install absorbent insert 50 into outer cover 20, a user may lay
outer cover 20 flat, inner surface 25 facing up, stretch and orient
insert 50 such that rear fastener component 57 faces rear insert
fastener component 32 and front fastener component 56 faces front
insert fastener component 33, and bring these respective fastener
component pairs 57, 32 and 56, 33 together to effect fastening
therebetween.
[0030] If it is desired that outer cover 20 be reusable, for outer
cover 20 to remain substantially sanitary and useful (without
requiring laundering or disposal) after removal and replacement of
an insert, it may be desired that all parts of outer cover 20
remain substantially unsoiled after an exudation of waste
(especially fecal matter) by the wearer. Thus, it may be desired
that when insert 50 is installed within an outer cover 20, there is
no non-removable portion or component of outer cover 20 that lies
over or covers a substantial portion of wearer-facing surfaces of
insert 50 (expressed differently, no non-removable portion or
component of outer cover 20 is situated between a substantial
portion of insert 50 and the wearer when the wearable absorbent
article is worn), at least in the areas proximate to wearer body
features that discharge exudates. Thus, it may be desired that
outer cover 20 include no non-removable cover sheet or the like
that covers or contains substantial portions of wearer-facing
surfaces of insert 50 within outer cover 20, nor any overlying
structures such as pockets, straps or flaps that substantially wrap
or cover the insert proximate to exudate discharge points, or lie
substantially between insert 50 and the wearer's anus and/or
genitals, when the wearable absorbent article is worn. If outer
cover 20 lacks such overlying structures, this may increase the
likelihood that the wearer's exudates will contact only insert 50,
and not portions of outer cover 20.
[0031] Referring to FIGS. 1, 2A and 2B, it can be seen that
wearable absorbent article 10 may be placed on a wearer by wrapping
outer cover 20 between the wearer's legs and under the buttocks
such that crotch region 26 is between the wearer's legs, bringing
front waist edge 21 and rear waist edge 22 into the positions
approximately as shown in FIG. 1, and then securing fastening ears
29 to front region 27, thereby forming a pant-like garment about
the wearer as suggested in FIG. 1. When insert 50 has been
installed into outer cover 20, insert 50 will then be disposed
within outer cover 20, next to the wearer, with the standing cuffs
53 oriented and extending longitudinally adjacent the inner
portions of leg edges 23 (i.e., longitudinally between the wearer's
legs).
[0032] Examples of Possible Outer Cover Details
[0033] Fastening System
[0034] Referring to FIGS. 2A and 2B, to enable fastening of
fastening ears 29 to front region 27, fastening ears 29 may have
outer cover fastener components 30 disposed thereon. Alternatively,
or in addition, front region 27 may have disposed thereon one or
more receiving fastener components 31 disposed thereon. Fastener
components 30, 31 may be selected so as to be cooperative to effect
fastening of ears 29 to front region 27.
[0035] In one example, outer cover fastener components 30 may
include a patch of hooks, and receiving fastener component 31 may
include a patch of loops. An example of a suitable hook-and-loop
fastening system is a VELCRO system (a product of Velcro Industries
B.V.) A hook-and-loop fastening system provides certain advantages.
Because the respective hook and loop components are supplied in
sheet form, they may be cut into suitably shaped patches that can
be affixed to a cloth or nonwoven substrate by various mechanisms,
including adhesive bonding, mechanical bonding, ultrasonic bonding,
sewing, stitching, serging, edging, and the like. If patches of
hooks or loops are affixed to fastening ears 29 to form outer cover
fastener components 30, as suggested by FIG. 2B, a laterally
extended patch of cooperating hook or loop material can be affixed
to outer cover front region 27 to form a receiving fastener
component 31, as suggested by FIG. 2A. By providing for fastening
of ears 29 to front region 27 at laterally varying locations
thereon, this arrangement provides for easy and simple
adjustability of waist opening size of the wearable absorbent
article.
[0036] In another example, as noted above, the outer cover
fastening system may include other types of fastener components. To
provide for waist opening size adjustability, fastener components
disposed on fastening ears 29 that cooperate with extended surfaces
or multiple cooperating fastener components disposed on front
region 27 may be used. Receiving fastener components may be
multiply disposed on front region 27 in laterally arranged, varying
locations, allowing for fastenability of respective ears 29 to
front region 27 at laterally varying locations.
[0037] Referring to FIG. 2B, outer cover 20 also may have one or
more respective fastener protectors 39 disposed thereon. This
feature may prevent fastener components having features likely to
randomly and unintentionally engage and catch on portions of the
outer cover, or other articles, during storage, carrying,
laundering and similar/related activities, from doing so, thereby
avoiding potential bunching, entangling and/or damage to either
outer cover 20 or other articles during such activities. For
example, if fastener components 30 are patches of hooks,
appropriately placed fastener protectors 39 may include patches of
corresponding loops. This will enable the user to fold ears 29 over
to engage them with fastener protectors 39, thereby holding them in
the folded-over position such that hooks thereon will be concealed
and prevented from snagging other articles when outer cover 20 is
not being worn.
[0038] Outer cover 20 also includes respective front and rear
visual indicia 73, 74 disposed on the front region 27 and rear
region 28, respectively. Respective visual indicia disposed on
insert 50 and outer cover 20 may be adapted to provide a visual cue
to the user of correct/optimal orientation and placement of insert
50 within outer cover 20.
[0039] Materials
[0040] Outer cover 20 and/or layers or portions thereof may be made
of any knitted, woven or nonwoven textile or textile-like material
that is appropriately compatible with skin of the intended
wearer(s). Outer cover 20 may be constructed of durable and/or
semi-durable materials. Generally, only for purposes of reference
in this description, "durable" refers to a woven or knitted textile
material of any kind that may be used as a component of a washable
clothing article. As used herein, "durable" includes materials
which are "launderable" as defined and described in co-pending U.S.
applications Ser. Nos. 12/687,412, 12/687,528, and 12/687,425,
entitled, respectively, "REUSABLE OUTER COVER FOR AN ABSORBENT
ARTICLE," "REUSABLE OUTER COVER FOR AN ABSORBENT ARTICLE HAVING
ZONES OF VARYING PROPERTIES," and "LEG AND WAISTBAND STRUCTURES FOR
AN ABSORBENT ARTICLE," by Donald C. Roe (Procter & Gamble
Attorney Docket Nos. 11557, 11558 and 11559), filed on the same day
hereof. Generally, only for purposes of this description,
"semi-durable" refers to a nonwoven material or laminate thereof
that when used as an outer cover material can withstand more than
one use with an insert without losing its structural integrity to
an extent that renders it unserviceable. As used herein,
"semi-durable" includes materials which are "laundering resistant"
as defined and described in the co-pending U.S. applications
identified immediately above. Thus, outer cover 20 may be
constructed of materials and construction that make it reusable
and/or washable.
[0041] Durable materials of which outer cover 20 may be constructed
may include any natural or synthetic textile materials known in the
diaper, pant, underwear, performance clothing, sport clothing, or
general clothing or textile arts. Durable materials may include
woven or knitted textiles made of natural fibers such as cotton,
linen, wool, bamboo, hemp, silk, rayon, and the like, as well as
blends of any of these fibers with any other(s), or with synthetic
fibers. Examples of synthetic fibers suitable for use as components
of durable materials include polyester, nylon, spandex and/or other
elastomer fibers. Durable outer cover materials also may include
breathable water repellent materials such as GORE-TEX (a product of
W. L. Gore & Associates, Inc., Elkton, Md.), fabrics comprising
microencapsulated phase-change polymer materials such as OUTLAST
COMFORTEMP fabrics (products of Outlast Technologies, Boulder,
Colo.--see U.S. Pat. No. 6,514,362 and U.S. Pat. No. 6,207,738, for
example), COOLMAX (a product of Invista, Wichita, Kans.), and the
like.
[0042] Suitable durable materials may be formed in any weave or
knit fabric form, including birdseye fabric, terry, fleece,
flannel, knits, stretch knits, sherpa, suedecloth, microfleece,
satin, velour, Burley knits, etc. Suitable examples include
POLARTECH POWER DRY, POWER STRETCH and WIND PRO (products of
Polartec, LLC, Lawrence, Mass.). Knitted textiles, which may be
more inherently stretchable and elastic than woven or nonwoven
materials, may impart better fit, comfort and/or appearance to the
outer cover. Incorporation of fibers of spandex or other elastomer
also may also enhance stretchability and elasticity, and thereby
impart better fit, comfort and/or appearance to the outer cover,
than textiles not including such elastomeric fibers.
[0043] Specific suitable examples for durable outer cover materials
include jersey knits of blends of: rayon (93%) and spandex (7%)
fibers; modal (94%) and spandex (6%) fibers; cotton and spandex
fibers; and bamboo and spandex fibers. Materials that have stretch
capability of equal to or greater than about 2.times. may be
desired. Suitable examples of materials may have basis weights of
about 0.09-0.15 gram/in..sup.2 per layer, or other basis
weights.
[0044] Durable outer cover materials may be selected to impart
desired comfort, appearance and performance to outer cover 20. In
some circumstances it may be desired to select durable outer cover
materials which are sufficiently inexpensive to allow for disposal,
if soiled extensively or damaged, with minimized issues of cost or
conscience.
[0045] Semi-durable outer cover materials may include any natural
or synthetic nonwoven web and/or film materials known in the diaper
or pant arts. Semi-durable materials of which outer cover 20 may be
constructed may include non-woven web materials of polypropylene
and/or polyethylene fibers, polyester fibers, and any other
synthetic fibers used to form nonwoven web materials used as
components of disposable diapers, and blends thereof. Natural
fibers such as cotton, linen, wool, bamboo, hemp, silk, rayon, and
the like may be blended with synthetic fibers to form such a
nonwoven web suitable as a component layer of outer cover 20.
[0046] Non-limiting examples of fibers, nonwovens and laminates of
nonwovens and films that might be considered for use as
semi-durable outer cover materials may be found in U.S. Pat. Nos.
7,223,818; 7,211,531; 7,060,149; 6,964,720; 6,905,987; 6,890,872;
6,884,494; 6,878,647; and 5,518,801; and U.S. Published
Applications Nos. 2008/0319407; 2008/0045917; 2007/0293111;
2007/0287983; 2007/0287348; 2007/0249254; 2007/0203301; and
2005/0164587.
[0047] Semi-durable outer cover materials also may be selected to
impart desired comfort, appearance and performance to outer cover
20. In some circumstances it also may be desired to select
semi-durable outer cover materials which are sufficiently
inexpensive to allow for disposal, if soiled extensively or
damaged, with minimized issues of cost or conscience.
[0048] The outer cover also, or additionally, may include a
laminated or substantially separate film layer, which may be
elastic, to provide enhanced liquid penetration resistance and/or
elastic properties. Elastic properties also can be added or
enhanced via the addition of other materials to the outer cover in
layer, band or strip fashion, including elastic strands, bands,
scrims, and the like. A film layer may be laminated with a durable
material or semi-durable material. A film layer may include an
elastomer based on KRATON (a product of Kraton Polymers U.S., LLC,
Houston, Tex.), or by way of further example, VISTAMAXX available
from ExxonMobil Chemical Company, Houston, Tex.; FLEXAIRE,
EXTRAFLEX or FABRIFLEX (products of Tredegar Film Products
Corporation, Richmond, Va.), and various latex-free elastomeric
sheets available from Fulflex Elastomerics Worldwide (Greenville,
Tenn.).
[0049] Inclusion of an elastomeric material, either as a fibrous
component of a cloth or nonwoven layer, or as a film layer,
provides for improved stretchability and elasticity where it may be
deemed useful to accommodate the wearer's anatomy and movements,
such as over the wearer's buttocks and/or around the waist areas,
and improved fit and comfort. Additionally, where a film layer may
be included, it may impart additional liquid containment capability
to the outer cover. A film layer may include a film that is
substantially liquid impermeable, but vapor permeable, so as to
provide breathability and reduce humidity within the outer cover
while it is being worn, reducing chances for over-hydration of the
skin where liquid containment capability is desired. A breathable
film also may be provided by mechanically perforating or aperturing
a film by various processes. Examples of such processes are
described in co-pending U.S. applications Ser. Nos. 12/366,825 and
12/534,353.
[0050] Referring to FIG. 2A, in one example outer surface 24 may be
formed by a first layer of a durable or semi-durable material. The
material selected may include fibers having hydrophobic properties,
providing enhanced liquid containment attributes to such first
layer. In another example, however, it may be desirable in some
circumstances for the selected material to include hydrophilic
fibers, or fibers treated to be hydrophilic, so as will cause the
material to more readily absorb and/or transmit liquid
therethrough. This may serve to provide supplemental absorbency
within the outer cover for the event in which liquid exudates
escape the insert, or to provide one way of communicating to the
user that liquid exudates have escaped the insert. Additionally, in
some circumstances it may be desirable that the material selected
have soft tactile properties so as to have a pleasant feel that the
user and/or wearer find attractive. The material also may be
selected so as to have a desired appearance, including but not
limited to coloration, sheen, texture, etc.
[0051] Outer cover 20 may be formed of a single layer of a durable
or semi-durable material, or may have two or more layers in the
front region 27 and/or rear region 28. Accordingly, referring to
FIG. 2B, in another example inner surfaces 25 may be formed by a
second layer of a durable or semi-durable material. The material
selected may include fibers having hydrophobic properties,
providing enhanced liquid containment attributes to the second
layer. In another example, however, it may be desirable in some
circumstances for the selected material to include hydrophilic
fibers, or fibers treated to be hydrophilic. This may be desired in
some circumstances to cause the material forming inner surfaces 25
to more readily absorb liquid, or transmit liquid therethrough.
This may serve to provide supplemental absorbency within the outer
cover for an event in which liquid exudates escape the insert,
reducing the likelihood that the outer cover will leak.
Alternatively, it may provide one way of communicating to the user
that liquid exudates have escaped the insert, by causing wetness to
be transmitted through to the outer cover outer layer such that
wetness is visible on outer surfaces. Alternatively, it may serve
to provide a layer that tends to draw moisture away from the skin,
for a drier, more comfortable feel.
[0052] Additionally, in some circumstances it may be desirable that
the material(s) selected for inner surfaces 25 have soft tactile
properties so as to have a pleasant feel against the skin,
particularly in areas where no portion of an insert is expected to
be present between the outer cover and the wearer's skin.
[0053] In another example, the second layer of material may be
formed of a textile material having enhanced elasticity, such as by
inclusion of fibers of an elastomeric material (such as spandex).
In another example, an intermediate film layer may be included,
laminated or not laminated with another layer.
[0054] Forming the outer cover 20 of more than one layer, for
example, two, or more, layers, as described above, may provide
various benefits. A second layer (and any additional layers) may
provide supplemental tensile strength in both the lateral and
longitudinal directions across the outer cover 20. Additionally, a
first layer may be selected for a first set of properties, and a
second layer may be selected for a second set of properties. For
example, material forming a first layer may be selected for having
comparatively greater elasticity and a particular texture, color
and/or other appearance-related properties, and material forming a
second layer may be selected for having comparatively greater
hydrophobicity, hydrophilicity and/or softness to the skin for
purposes of an inner layer, the two layers in combination imparting
a combination of desirable attributes to the outer cover. For
example, the inner layer may be formed of material(s) and/or
treated to be more hydrophilic so as to provide for absorbency and
reduced chances of fluid runoff (leakage), while the outer layer
may be formed of material(s) that are more hydrophobic, so as to,
e.g., resist environmental soiling, or resist liquid transmission
from the inner layer to the outer layer. Additionally, a plurality
of layers may better serve to conceal bumps, corners, seams or
other features of an insert, as compared with a single layer, for a
smoother, more attractive appearance.
[0055] Reusable outer covers designed to hold disposable absorbent
inserts are comfortable and fit the contours of the wearer's body.
Outer cover materials should have a low bending stiffness to enable
them to adapt and conform to the wearer's anatomy and move with the
wearer's body with a minimum of resistance, leading to a
comfortable fit whether the wearer is quiescent or active. A
conforming fit also allows the perimeter region of the outer cover,
which may include elasticized leg or waist bands, to remain in a
desirable relative orientation and location on the wearer's body to
prevent leakage of bodily exudates.
[0056] The outer cover "as used" may be constructed of a unitary
element, such as a single layer of material or a bonded laminate of
two or more materials. Alternatively, the outer cover may be
constructed of two or more discrete layers of material, having
similar or different properties. In the latter case, the two or
more discrete layers of material may be joined together at or near
the perimeter of the article, e.g., in a seam or attachment point
of a leg or waistband, or may be joined at one or more discrete
locations in the article, such as at locations where a fastening
element is affixed to the inner or outer surface of the outer
cover. Regardless of the number of layers, or "stack up", the
bending stiffness of the "as used" stack up of the outer cover
material may be less than about 0.20 N, or 0.19 N, in the Bending
Stiffness test described herein. If the outer cover includes more
than one discrete layer (i.e., separable from another layer of the
outer cover over a sufficient area to enable the Bending Stiffness
test to be performed, the Bending Stiffness of at least one of the
layers may be less than about 0.10 N or less than about 0.08 N. In
some embodiments, each layer may have a Bending Stiffness of less
than about 0.10 N or 0.08 N.
[0057] The addition of a fastening element to the wearer-facing
surface of the outer cover may require, in some embodiments, a
higher Bending Stiffness to create additional support to carry the
loading force transferred from the insert to the outer cover
material. The Bending Stiffness of the "as used" stack up of outer
cover material to which an insert-to-outer cover material is
affixed may be less than about 0.30 N.
[0058] Table 1, shown below, shows test data for outer cover
flexibility from the testing of whole outer cover samples of four
current market absorbent articles and from a Test Article. The four
current market products were the gDiaper (size large, from
gDiapers, Inc. of Portland, Oreg., United States purchased in April
2010 from www.gdiapers.com), the GroBaby/Gro Via (from The Natural
Baby Co. of Bozeman, Mt., United States purchased in April 2010 at
www.thenaturalbabyco.com), the Bummis SuperBrite (size large, from
Bummis, Inc., of Montreal, Quebec, Canada purchased in April 2010
from www.thenaturalbabyco.com), and the Diaperaps (size large, from
Diaperaps: Baby's Organic Nursery, Granada Hills, Calif., United
States purchased in April 2010 from
www.babysorganicnursery.com).
[0059] The Test Article outer cover was configured according to
embodiments of the present disclosure, with an outer layer material
and inner liner material both made of 93% Modal and 7% Spandex,
available as code E.n.n-14 from Koshtex, Los Angeles, Calif.,
United States, outer cover hooks made of 100% nylon, available as
sewable hooks from Perfectek Plus, Huntington Beach, Calif., United
States, outer cover landing zone, available as code 960E from
Aplix, Paris, France, and insert landing zone made of 100% nylon,
available as standard sew on material from Touchtape, St.
Augustine, Fla., United States.
TABLE-US-00001 TABLE 1 Test gDiaper GroBaby Bummis Diaperaps
Article outer outer outer outer outer cover cover cover Cover cover
Bending 0.355 0.381 0.261 0.206 0.183 stiffness peak force
(Newtons)
[0060] For the test data in Table 1, for each type of outer cover,
ten samples were tested, and the average was reported. The outer
cover bending stiffness peak force was measured by using the
Bending Stiffness Test, disclosed herein. Also, for the Test
Article, the bending stiffness peak force of the outer layer
material was measured using the Bending Stiffness Test, and was
found to be 0.070 Newtons. Further, for the Test Article, the
bending stiffness peak force of the inner liner material was
measured using the Bending Stiffness Test, and was found to be
0.056 Newtons.
[0061] In addition to forming differing layers of differing
materials, it may be desirable to form a single layer of differing
materials, for example, differing materials in the respective
front, crotch and/or rear regions of the outer cover. Such
differing materials may be joined at a seam such as inner seam 40
and/or outer seam 41. For example, the material predominately
forming the inner surface of rear region 28 may be selected
primarily for its elasticity features, which may better serve to
provide snug fit about wearer body contours and accommodate wearer
movement (i.e., about the buttocks and hips). By comparison, the
material predominately forming the inner surface of front region 27
and/or crotch region 26 might be selected primarily for its
hydrophobicity or hydrophilicity, which may better serve to contain
liquid exudates.
[0062] Layers or other elements of the outer cover may be joined to
each other via any suitable mechanism, including, for example,
adhesives, mechanical bonding, ultrasonic bonding, sewing,
stitching, serging, edging, and the like.
[0063] Additionally or alternatively to the constructions and
materials described above, the outer cover may be constructed and
may include materials and features as described in co-pending U.S.
applications Ser. Nos. 12/687,412, 12/687,528, and 12/687,425,
entitled, respectively, "REUSABLE OUTER COVER FOR AN ABSORBENT
ARTICLE," "REUSABLE OUTER COVER FOR AN ABSORBENT ARTICLE HAVING
ZONES OF VARYING PROPERTIES," and "LEG AND WAISTBAND STRUCTURES FOR
AN ABSORBENT ARTICLE," by Donald C. Roe (Procter & Gamble
Attorney Docket Nos. 11557, 11558 and 11559), filed on the same day
hereof.
[0064] Elasticized Waistbands, Leg Bands
[0065] Referring again to FIGS. 1, 2A and 2B, front waist band
portion 34, rear waist band portion 35, and leg band portions 36
are depicted. One or more of these band portions 34, 35, 36 may be
formed of one or more strands or strips including an elastomeric
material such as spandex or a blend of spandex and other fibers,
enveloped by a nonwoven or textile material, which may include the
edges of the material forming the inner and/or outer layers of
outer cover 20, to form and elasticize the respective band
portions. The elastic material may be affixed to or within an outer
cover layer in a strained condition, or at zero applied strain.
Textile material(s) enveloping the elastic strand(s) or strip(s)
may be sewn around elastic strand(s) or strip(s) to hold them in
place within the respective band portions. If the elastic material
is strained prior to, and while, being enveloped and affixed to
form these band portions during the manufacturing process, upon
relaxation the enveloping material and adjacent outer cover
material may be caused to gather and form ruffles 37 therealong,
which constitute gathered outer cover material. This can serve to
promote snug fit, wearer comfort and appearance. The band portion
may be disposed along the edge of the outer cover, and in some
circumstances it may be desired to have the band portion situated
along substantially the entire length of the leg and/or waist
openings so as to form bands that substantially or completely
encircle the wearer's legs and/or waist while outer cover 20 is
worn. The gathered material within ruffles 37 can serve to
accommodate stretching of waist band portions 34, 35 and leg band
portions 36. This arrangement including elasticized leg band
portions 36 as described, not only may provide for better fit about
the wearer's legs, but also may enable the outer cover 20, when
formed of appropriately sized and shaped material, to form a
pouch-like structure 75 in the crotch region (see FIG. 1) when
worn, which may serve to provide space within the outer cover to
accommodate the insert 50 (FIG. 3) and help hold it in place within
outer cover 20, in a substantially laterally centered position
within the crotch region. This may be deemed advantageous in
examples in which an insert 50 is attached within outer cover 20 by
fastener components only located proximate to the respective ends
of insert 50, and not at any longitudinally intermediate locations,
as described further below. Alternatively, or additionally, the
elastic strands or strips in waist band portions 34, 35 and leg
band portions 36 may be affixed within the outer cover only at or
near their respective ends, e.g., within a pouch, tube or envelope
structure formed of outer cover material--referred to herein as a
"drawstring elastic". This will allow the elastic material and
associated outer cover material to stretch and move freely and
independently of each other, which may promote fit and comfort. A
snug fit about the wearer's legs provided by such elasticized leg
band portions 36 may serve to enhance containment capability of the
wearable absorbent article.
[0066] One or more of waist band portions 34, 35 and leg band
portions 36 may be elasticized in the manner described above, or by
other mechanisms. For example, elasticized band/strip material such
as that used to form elastic waistbands and leg bands or other
banding features of conventional cloth underwear, briefs or other
articles of clothing may be separately produced, and affixed to the
materials forming outer cover 20 in any suitable manner, during the
manufacture thereof.
[0067] In another example, one or more of waist band portions 34,
35 and leg band portions 36 may be formed of elastic material
simply affixed about the leg opening and/or waist opening edges by
use of adhesive and/or compression bonding. In another example, an
elastic strip material may formed by affixing a plurality of
strained elastomeric strands or strips to one or more strips of
unstrained nonwoven web material, or film. When the resulting
elastic strip material is allowed to relax, the unstrained material
forms transverse rugosities that comprise gathered unstrained
material, which will accommodate stretching of the elastic strip
material. By affixing the elastic strip material at one or more of
waist band portions 34, 35 and/or leg band portions 36, the elastic
strip material may be used to form one or more of elasticized waist
band portions 34, 35 and/or leg band portions 36.
[0068] Anchoring Bands
[0069] Outer cover 20 also may include an anchoring supplement such
as anchoring band 38a and 38b (collectively referred to as
anchoring bands 38) disposed on or in the outer cover rear region
28 as indicated in FIGS. 2A, 2B. As suggested in FIGS. 2A and 2B,
anchoring band 38 may be affixed along a layer, or disposed between
layers, forming inner surfaces 25 and outer surfaces 24 of outer
cover 20. Anchoring band 38 may include an elastomeric or
elasticized strip or band of material, affixed to outer cover 20 at
locations proximate to its rearward corners or proximate to
fastening ears 29. Thus, anchoring band 38 may be partially or
substantially force-decoupled from the other layer(s) of the outer
cover along its lateral length from the layer(s) forming the inner
and outer surfaces of outer cover 20, via attachment to the outer
cover only by the ends of anchoring band 38, or only at a limited
number of selected intermediate lateral locations along anchoring
band 38. For example, anchoring band 38 might be attached to outer
cover 20 only at the ends of anchoring band 38. In another example,
anchoring band 38 might be attached to outer cover 20 only at the
ends and at the lateral center of anchoring band 38. This
substantially force-decoupled arrangement allows anchoring band 38
and surrounding portions of outer cover 20 to stretch and move
substantially independently of one another, which may promote
better fit and comfort. In another example, however, anchoring band
38 may be an elastic band, strip or strap laminated with or
otherwise affixed to a layer of stretchable material forming either
of or both the inner and outer surfaces of the outer cover, along
substantially the entire length of anchoring band 38.
[0070] When strained laterally by application to the wearer,
anchoring band 38 may serve to provide, or supplement, lateral
tensile forces in the article about the wearer's waist, thereby
tending to draw the waist opening snug, enhancing fit and enhancing
securement of the wearable absorbent article about the wearer's
waist. The elastic modulus of the anchoring band may be higher than
the elastic modulus of the surrounding, adjacent, or coextensive
outer cover materials.
[0071] An anchoring band, or system of one or more anchoring band
members, may have any additional features described in, for
example, co-pending U.S. patent applications Ser. Nos. 11/810,741;
11/810,708; 12/101,476; 12/028,317; 11/810,745; 11/810,742;
11/810,734; 11/810,779; 11/810,715; 11/810,733; 11/810,736;
11/810,777; and 11/599,862; 11/810,901 and 11/599,851; 11/899,812;
12/204,844; 12/204,849; 12/204,854; 12/204,858; and 12/204,864;
11/899,810; 11/899,656; and 11/899,811; 11/899,812; 12/204,844;
12/204,849; 12/204,854; 12/204,858; and 12/204,864; and co-pending
U.S. applications Ser. Nos. 12/687,412, 12/687,528, and 12/687,425,
entitled, respectively, "REUSABLE WEARABLE ABSORBENT ARTICLES WITH
ANCHORING SYSTEMS," "REUSABLE WEARABLE ABSORBENT ARTICLES WITH
ANCHORING SUBSYSTEMS," and "REUSABLE OUTER COVERS FOR WEARABLE
ABSORBENT ARTICLES," by Donald C. Roe (Procter & Gamble
Attorney Docket Nos. 11225M, 11565 and 11566), filed on the same
day hereof.
[0072] In another example, instead of, or in addition to, being
oriented substantially laterally as suggested by the depicted
location of anchoring band 38 in FIGS. 2A and 2B, one or more
members forming anchoring bands may be oriented diagonally between
the longitudinal and lateral directions. For example, as suggested
in FIG. 2A, a pair of diagonal anchoring bands 38a may have
respective waist ends thereof affixed at a location area proximate
to corners of the outer cover and/or fastening ears 29, and
respectively extend toward both the lateral and longitudinal center
of outer cover 20, as suggested in FIG. 2A. The respective center
ends of bands 38a may be affixed to the outer cover at locations
proximate the lateral center of the outer cover as suggested in
FIG. 2A, and bands 38a may be either force-decoupled or
force-coupled to the outer cover along the lengths of bands 38a, as
described above. In an example where an insert is connected to an
anchoring band for additional longitudinal support as described
further below, diagonal anchoring bands such as diagonal anchoring
bands 38a may serve to provide supplementary longitudinal tension
along outer cover 20, providing supplemental longitudinal support
therewithin.
[0073] Examples of Possible Absorbent Insert Details
[0074] Examples of features of an absorbent insert 50 will be
described with reference to FIGS. 3 and 4.
[0075] As noted above, FIG. 3 depicts a disposable absorbent insert
50 that may form an inner component of a wearable absorbent article
as described herein, shown in perspective view as it might appear
in a free-standing, relaxed state, apart from an outer cover. FIG.
4 depicts an example of an insert 50 shown stretched out and laid
flat (against elastic-induced contraction to a position similar to
that shown in FIG. 3), body-facing surfaces facing the viewer.
[0076] Insert 50 may have a topsheet 51 and backsheet 52 forming an
envelope-like enclosure for absorbent core materials such as those
described further below. Topsheet 51 and backsheet 52 may be
affixed together along longitudinal seams, and along lateral seams
69. Insert 50 also may have longitudinal standing cuffs 53 affixed
therealong.
[0077] Insert 50 also may include respective forward and rearward
user grasp structures 59, 61. User grasp structures 59, 61 may be
provided to enable the user to quickly and easily grasp insert 50
proximate its respective ends.
[0078] Referring to FIGS. 3 and 4, end support stiffeners 60 and 62
may be included. Such end support stiffeners may serve to aid the
user in engaging the insert with the outer cover, and to help
insert 50 maintain its intended shape and configuration while being
worn beneath an outer cover, i.e., help maintain the intended
position and gasketing function of the standing cuffs 53. End
support stiffeners 60, 62 also may help control the corners of the
insert regardless of the size, type or location of fastener
components included on the insert. In addition to providing
resistance to longitudinal pull of cuff edges 58, end support
stiffeners 60, 62 may provide resistance to bending in any
direction or plane.
[0079] Topsheet
[0080] Topsheet 51 may be formed of a liquid-permeable nonwoven web
material. It may be desired that material forming topsheet 51 is
compliant, soft-feeling, and non-irritating to the wearer's skin.
It may be desired that at least a portion of topsheet 51 may be
liquid pervious, 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 (e.g.,
polyester or polypropylene fibers), or a combination of natural and
synthetic fibers. If topsheet 51 includes fibers, the fibers may be
spunbond, carded, wet-laid, meltblown, hydroentangled, or otherwise
processed as is known in the art.
[0081] One suitable material comprising a nonwoven 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. Additional suitable materials comprising
formed films are described in U.S. Pat. Nos. 3,929,135; 4,324,246;
4,342,314; 4,463,045; and 5,006,394. Other suitable topsheets 30
may be made in accordance with U.S. Pat. Nos. 4,609,518 and
4,629,643. Suitable examples of formed and/or apertured films may
include products produced by The Procter & Gamble Company of
Cincinnati, Ohio as DRI-WEAVE, and by Tredegar Corporation, based
in Richmond, Va., as FRESHFEEL. Suitable topsheet materials also
may include laminates of films and nonwoven webs produced by
Tredegar as COMFORTFEEL, COMFORTQUILT, SOFTQUILT and
COMFORTAIRE.
[0082] In some circumstances it may be desired that at least a
portion of topsheet 51 is made of a hydrophobic material or is
treated to be hydrophobic in order to isolate the wearer's skin
from liquids contained in absorbent core. If topsheet 51 is
generally made of a hydrophobic material, it may be desired that at
least a portion of the upper surface of topsheet 51 is treated to
be hydrophilic so that liquids will transfer through the topsheet
more rapidly. Topsheet 51 can be rendered hydrophilic by treating
it with a surfactant or by incorporating a surfactant into the
topsheet. Suitable methods for treating topsheet 51 with a
surfactant include spraying the topsheet material with the
surfactant and/or immersing the material into the surfactant. A
more detailed discussion of such a treatment and hydrophilicity is
contained in U.S. Pat. Nos. 4,988,344 and 4,988,345. A more
detailed discussion of some suitable methods for incorporating a
surfactant in the topsheet can be found in U.S. Statutory Invention
Registration No. H1670. In another example, however, topsheet 51
may include an apertured web or film which is hydrophobic. This may
be accomplished by foregoing the hydrophilizing treatment step from
the production process and/or applying a hydrophobic treatment to
the topsheet material, such as a polytetraflouroethylene compound
like SCOTCHGUARD or a hydrophobic lotion composition, as described
below. In such examples, it may be desired that the apertures be
large enough to allow the penetration of aqueous fluids like urine
without significant resistance otherwise attributable to
hydrophobicity. It may also be desired that the apertures have
sufficient effective open area and/or aperture size to allow the
penetration of low-viscosity fecal material. Examples of topsheets
meeting these requirements are described in U.S. Pat. Nos.
5,342,338; 6,414,215; and 6,010,491.
[0083] Any portion of topsheet 51 may be coated with a lotion or
skin care composition as is known in the art. Examples of suitable
lotions include those described in U.S. Pat. Nos. 5,607,760;
5,609,587; 5,635,191; 5,643,588; 5,968,025 and 6,716,441. The
lotion may function alone or in combination with another agent as
the hydrophobizing treatment described above.
[0084] Topsheet 51 may also include or be treated with
antibacterial agents, some examples of which are disclosed in U.S.
application Ser. No. 08/212,441, published as U.S. Statutory
Invention Registration H1732.
[0085] Topsheet 51, backsheet 52 or any portion of the topsheet or
backsheet may be embossed and/or matte finished to provide a more
cloth-like appearance.
[0086] Topsheet 51 may be fully or partially elasticized or may be
foreshortened so as to provide a void space between topsheet 51 and
core. Exemplary structures including elasticized or foreshortened
topsheets are described in more detail in U.S. Pat. Nos. 4,892,536;
4,990,147; 5,037,416; and 5,269,775.
[0087] Backsheet
[0088] Backsheet 52 is generally that outer liner portion of insert
50 forming the garment-facing surface thereof, and prevents the
exudates absorbed and contained within insert 50 from wicking
through and soiling the outer cover. In some circumstances it may
be desired that backsheet 52 is substantially impervious to
liquids.
[0089] Backsheet 52 may be formed of a film, a nonwoven, or a
laminate of a film and a nonwoven. Backsheet 52 may be formed of a
substantially liquid-impermeable laminate or composite of film and
non-woven web. Backsheet 52 may be formed of a substantially liquid
impermeable nonwoven web, or laminate of nonwoven web and
substantially liquid impermeable film, so as to contain and isolate
liquid exudates from the outer cover, outer clothing and/or
environment of the wearer. At the same time, backsheet 52 may be
vapor permeable to provide for breathability of the insert and the
wearable absorbent article, reducing humidity in the areas between
the insert and the wearer's body, and helping reduce the likelihood
of skin irritation and/or rashes that may result from
over-hydration of the skin.
[0090] The material forming backsheet 52 may include a thin plastic
film such as a thermoplastic film having a thickness of about 0.012
mm (0.5 mil) to about 0.051 mm (2.0 mils). Suitable backsheet
materials also may be breathable materials which permit vapors to
escape while still preventing liquid from passing therethrough.
Suitable examples may include those manufactured by Tredegar
Corporation, based in Richmond, Va., and sold under the trade names
CPC2, X15306, X10962 and X10964 film. Other examples may include
microporous films such as manufactured by Mitsui Toatsu Co., of
Japan under the designation ESPOIR NO and by Exxon Chemical Co., of
Bay City, Tex., under the designation EXXAIRE, and monolithic films
such as manufactured by Clopay Corporation, Cincinnati, Ohio under
the name HYTREL blend P18-3097. Some additional examples may
include breathable composite materials as described in PCT
Application No. WO 95/16746; and U.S. Pat. Nos. 5,938,648;
5,865,823; and 5,571,096. In other examples, backsheet 52 may
comprise elastomeric films, foams, strands, or combinations of
these or other suitable materials with nonwovens or synthetic
films.
[0091] In certain embodiments, the backsheet may have a water vapor
transmission rate (WVTR) of greater than about 2000 g/24 h/m.sup.2,
greater than about 3000 g/24 h/m.sup.2, greater than about 5000
g/24 h/m.sup.2, greater than about 6000 g/24 h/m.sup.2, greater
than about 7000 g/24 h/m.sup.2, greater than about 8000 g/24
h/m.sup.2, greater than about 9000 g/24 h/m.sup.2, greater than
about 10000 g/24 h/m.sup.2, greater than about 11000 g/24
h/m.sup.2, greater than about 12000 g/24 h/m.sup.2, greater than
about 15000 g/24 h/m.sup.2, measured according to WSP 70.5 (08) at
37.8.degree. C. and 60% Relative Humidity. A higher WVTR may be
desired in this particular application, since the insert backsheet
52 will not form the outer surface of the wearable article, as a
conventional disposable diaper backsheet would, but rather, will be
covered by the one or more layers of the outer cover
material(s)--which themselves may act in some circumstances to
reduce WVTR of the composite structure.
[0092] Backsheet 52 may be joined to topsheet 51, absorbent core or
any other element of insert 50 by any suitable attachment mechanism
known in the art. For example, the attachment mechanism may include
a continuous line or layer of adhesive, a patterned layer of
adhesive, or an array of separate lines, spirals, or spots of
adhesive. One example of an attachment mechanism comprises an open
pattern network of filaments of adhesive as disclosed in U.S. Pat.
No. 4,573,986. Other suitable attachment mechanisms include 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. Nos. 3,911,173; 4,785,996; and 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 mechanism may comprise heat bonds,
pressure bonds, ultrasonic bonds, dynamic mechanical bonds, or any
other suitable attachment mechanisms or combinations of these
attachment mechanisms known in the art.
[0093] It will be appreciated that the outer cover described above
can be constructed of materials and construction so as to bear and
sustain a majority of the structural loading generally imposed upon
a disposable diaper, by stretching and accommodation of the
wearer's anatomical features and body movements, and by absorption,
swelling and added weight resulting from the wearer's exudations of
waste. Thus, lesser requirements for structural strength of an
insert might be present with use of such an outer cover, as
compared with strength required of inside components of a
disposable diaper. Therefore, an article such as described herein
may include a disposable absorbent insert manufactured from
materials that are different from those ordinarily used in the
manufacture of disposable diapers, such as petroleum-derived
materials, e.g., polyethylene and polypropylene. For example, a
disposable absorbent insert having one or more of a topsheet,
backsheet, standing cuffs and/or other components formed of
products of wood, cotton, flax (linen), hemp, bamboo, or other
cellulose fibers (e.g., paper), in addition to the materials
identified above, is contemplated. If resistance to aqueous liquid
penetration or substantial liquid impermeability is desired, e.g.,
for a backsheet and/or standing cuffs, a material formed of
ordinarily hydrophilic fibers such as paper may be coated or
impregnated with a hydrophobic material, such as a skin-compatible
oil or wax, to impart the desired resistance to aqueous liquid
penetration. Each of the materials forming the insert may be
selected so as to be dispersible in water or an aqueous solution,
flushable, biodegradable and/or compostable (preferably to an
agriculturally usable humus or soil amendment).
[0094] Absorbent Core
[0095] Insert 50 may have an absorbent core within the
envelope-like structure formed by topsheet 51 and backsheet 52.
Absorbent core may comprise any absorbent material which is
generally compressible, conformable, non-irritating to the wearer's
skin, and capable of absorbing and retaining liquids such as urine
and other certain body exudates. Absorbent core may comprise a wide
variety of liquid-absorbent materials commonly used in disposable
diapers and other absorbent articles such as comminuted wood pulp,
which is generally referred to as airfelt. Examples of other
suitable absorbent materials include creped cellulose wadding;
meltblown polymers, including coform; chemically stiffened,
modified or cross-linked cellulosic fibers; tissue, including
tissue wraps and tissue laminates; absorbent foams; absorbent
sponges; superabsorbent polymers; absorbent gelling materials; or
any other known absorbent material or combinations of
materials.
[0096] Absorbent core may include liquid acquisition/distribution
material, and storage material. Generally, acquisition/distribution
material may have comparatively rapid absorption and wicking
properties, but also may have limited absorption capacity.
Conversely, generally, storage material may have comparatively
slower absorption and wicking properties, but also may have greater
absorption capacity. Thus, acquisition/distribution material may
serve to rapidly absorb and distribute gushes of liquid such as
urine, while storage material, having greater absorption capacity,
may serve to absorb such liquid from the acquisition/distribution
material and store it for the time needed until the insert may be
replaced.
[0097] Absorbent wearable articles comprising at least one reusable
element, such as a reusable outer cover, and one disposable
element, such as a disposable absorbent insert adapted to be
releasably and functionally joined to said reusable element, may be
packaged together to enable a prospective user or caregiver to
select an appropriate variants of each element for the intended
use. For example, a package may contain one or more reusable outer
covers and one or more disposable absorbent inserts adapted to be
used therewith. The inserts may be specifically designed to be used
with the given outer cover. For example, the outer cover may be
sized for a specific range of wearers and the insert may have
dimensions particularly relevant for use by a wearer of that size.
Or the outer cover may have one or more fastener elements disposed
on its wearer-facing surface having a type, geometry, or spacing
with which one or more corresponding and complementary fastening
elements on the garment-facing surface of the insert are
particularly adapted to function or align. Or the absorbent
capacity of the insert may be adapted to acquire and contain a
large enough amount of urine from a given size wearer to enable the
article to be suitable for reliable and confident overnight usage.
Generally, at least about 200 grams of urine capacity, as measured
by the Centrifuge Retention Capacity test disclosed herein, is
required for overnight usage of disposable inserts by infant or
toddler wearers. More typically, the desirable overnight capacity
of a disposable insert may be at least about 225 grams, 250 grams,
300 grams, or 350 grams. In order to minimize the usage of
materials, and the energy associated in their production which may
contribute to global warming, it is desirable that the absorbent
efficiency of the insert be as high as possible. Generally, the
normalized capacity of the disposable absorbent insert is at least
about 8.0 g/g, and may be at least about 10.0 g/g.
[0098] In various embodiments of the present disclosure, a
disposable absorbent insert, configured for use with a reusable
outer cover, can have an insert absorbent capacity, measured
according to the Centrifuge Retention Capacity Test, of at least
150 grams, at least 200 grams, at least 250 grams, at least 300
grams, at least 350 grams, at least 400 grams, or any integer value
for grams between any of these values, or any range formed by any
of these values.
[0099] In various embodiments of the present disclosure, a
disposable absorbent insert, configured for use with a reusable
outer cover, can have an absorbent insert mass of less than 60
grams, less than 50 grams, less than 40 grams, less than 30 grams,
less than 20 grams, or any integer value for grams between any of
these values, or any range formed by any of these values.
[0100] Absorbent core may be manufactured in a wide variety of
sizes and shapes (e.g., rectangular, hourglass, "T"-shaped, etc.).
The configuration and construction of absorbent core may also be
varied (e.g., the absorbent core(s) or other absorbent structure(s)
may have varying caliper zones, hydrophilic gradient(s), a
superabsorbent gradient(s), or lower average density and lower
average basis weight acquisition zones; or may comprise one or more
layers or structures). Examples of absorbent structures for use as
absorbent core may include those described in U.S. Pat. Nos.
4,610,678; 4,673,402; 4,834,735; 4,888,231; 5,137,537; 5,147,345;
5,342,338; 5,260,345; 5,387,207; and 5,625,222.
[0101] To reduce the overall size and/or thickness of the absorbent
core, and thereby improve wearer comfort and reduce the volume of
disposable waste created by a soiled insert, it may be desired to
construct an absorbent core using the lowest volumes of core
materials possible within performance constraints. Toward this end,
examples of suitable materials and constructions for a suitable
absorbent core are described in, but are not limited to, copending
U.S. applications Ser. Nos. 12/141,122; 12/141,124; 12/141,126;
12/141,128; 12/141,130; 12/141,132; 12/141,134; 12/141,141;
12/141,143; and 12/141,146. These applications generally describe
absorbent core constructions that minimize or eliminate the need
for and inclusion of airfelt or other forms of cellulose fiber in
combination with particles of superabsorbent polymer (hereinafter,
"substantially airfelt-free cores"). Airfelt and other cellulose
fiber have been used as absorbent fillers in absorbent cores of
disposable diapers. Such fiber possesses absorbent properties and
imparts some absorption capacity to an absorbent core, but also is
included to provide a structural matrix to hold dispersed particles
of superabsorbent polymer and/or absorbent gelling material. While
inclusion of such particles enhances absorption capacity, keeping
such particles suitably dispersed may be important to prevent the
particles from "gel-blocking" in use as they swell with absorbed
liquid, causing loss of absorption capacity. The inclusion of
airfelt or other cellulose fiber as a matrix for superabsorbent
particles can serve to reduce or prevent gel-blocking. However, it
also imparts bulk to an absorbent core, even before absorption of
any liquids.
[0102] An absorbent core having a portion that is substantially
airfelt-free may be disposed between the topsheet 51 and the
backsheet 52. The core may include a layer formed at least in part
of a substrate, distributed absorbent particles of a superabsorbent
polymer or absorbent gelling material, and a thermoplastic adhesive
composition capturing the distributed absorbent particles and
adhering to at least portions of the substrate, thereby
immobilizing the absorbent particles on or proximate to, and
relative to, the substrate.
[0103] Features of an outer cover 20 as described herein provide
for a wearable absorbent article that has a relatively improved,
garment-like (or underwear-like) fit, comfort and appearance (as an
outer garment or under other clothes), as compared with many types
of wholly disposable diapers currently available. If an outer cover
20 having such attributes is used with an insert 50 having an
absorbent core incorporating substantial amounts of airfelt or
other cellulose fiber, the improved, garment-like fit, comfort and
appearance provided by the outer cover 20 may be compromised by the
bulkiness of the insert. In order to better preserve some or most
of the improved, garment-like fit, comfort and appearance of the
outer cover 20, therefore, it may be desirable to construct
absorbent core of insert 50 with features as described in one or
more of patent applications cited immediately above, which provide
for a relatively thin absorbent core.
[0104] In addition to providing an absorbent core having reduced
bulk, the substantially airfelt-free core may generally be more
flexible than an absorbent core containing substantial amounts of
airfelt or other cellulose fiber. This enhanced flexibility may
enable the core and the associated insert to better conform about
the wearer's body when in use, providing for improved comfort and
less bulky appearance of the wearable article 10.
[0105] Additionally, by reducing or eliminating airfelt or other
cellulosic fiber material, the substantially airfelt-free core
reduces the amount of materials consumed in manufacturing, reduces
the amount of space (and in some circumstances, weight) per unit
which must be packaged and shipped, conserving resources in that
regard, and reduces the amount of materials and bulk which must be
disposed of in connection with disposing of a used/soiled
insert.
[0106] Standing Cuffs
[0107] Insert 50 also may have a pair of longitudinal standing
cuffs 53 attached partially or entirely along the length thereof.
Suitable longitudinal standing cuffs (in various published examples
identified as "leg cuffs", "barrier cuffs" "gasketing cuffs," etc.,
may be formed of materials and construction such as described in,
but not limited to, U.S. Pat. Nos. 6,786,895; 6,420,627; 5,911,713;
5,906,603; 5,769,838; 5,624,425; 5,021,051 and 4,597,760; and
copending U.S. Published Application No. 2007/0239130 and U.S.
application Ser. No. 11/195,272. As shown in FIG. 3, standing cuffs
53 may have one or more strands or strips of cuff elastics 58a, 58b
disposed longitudinally therealong cuff edges 58. If such cuff
elastics 58a, 58b are pre-strained prior to being affixed to the
web material forming standing cuffs 53, resulting longitudinal
tensile forces therealong will cause the web material forming
standing cuffs 53 to gather as shown, and cause the cuffs to extend
from the body of the insert (upwardly relative to FIG. 3), or
causing them to "stand". This feature causes standing cuffs 53 to
form a gasketing structure along the wearer's body when the article
including insert 50 is worn, longitudinally on either side of the
anatomical features where waste is exuded. Thus, standing cuffs 53
may serve to enhance the exudate containment capability of insert
50 and, and as a result, of the wearable absorbent article. As with
backsheet 52, standing cuffs 53 may be formed of a substantially
liquid impermeable web so as to contain and isolate liquid exudates
from the outer cover, outer clothing and environment of the wearer.
At the same time, standing cuffs 53 may be vapor permeable to
provide for breathability of the insert and the wearable absorbent
article, reducing humidity in the areas between the insert and the
wearer's body, and helping reduce the likelihood of skin irritation
and/or rashes that may result from over-hydration of the skin.
[0108] In another example, the material forming standing cuffs 53
may be integral with the material forming backsheet 52, such as
described in, by way of non-limiting example, copending U.S.
Published App. No. 2007/0239130. In this particular example,
referring to and relative to the view in FIG. 3, a continuous piece
of material may form one standing cuff 53, wrap beneath the insert
to form backsheet 52, and wrap up the other side to form the other
standing cuff 53. This example of a wraparound construction may
provide improved liquid containment capability to insert 50, by
eliminating seams along the outer liquid-containing surfaces that
include standing cuffs 53 and backsheet 52. Another example of this
construction is depicted and described in U.S. Pat. No.
4,808,178.
[0109] In some circumstances, however, manufacturing and/or
economic constraints may discourage such construction, or else, it
may be desirable for the materials forming standing cuffs 53 and
backsheet 52 to have differing properties. For example, in some
applications it may not be deemed necessary for standing cuffs 53
to be substantially liquid impervious, if they are otherwise formed
of a nonwoven web material comprising closely situated hydrophobic
fibers, which may still tend to repel and contain fluid, but may be
generally more breathable than substantially liquid impervious
laminates including films. In this event, improved strength and
liquid containment attributes can still be imparted by having the
material forming standing cuffs 53 wrap only partially beneath the
lower longitudinal corners of the insert, and affixed at seams
beneath the insert, rather than at its outermost lower corners as
suggested by FIG. 3. One example of this construction is depicted
and described in U.S. application Ser. No. 11/158,563, and in
particular, FIG. 13 therein and associated descriptive text.
[0110] It is contemplated that an article of commerce including one
or a plurality of outer covers and one or a plurality of inserts,
as described herein, may be prepared and sold as such, as described
in co-pending U.S. patent application Ser. No. 12/687,538, filed
Jan. 14, 2010, and entitled, "Article of Commerce Including
Two-Piece Wearable Absorbent Article," by Donald C. Roe (Procter
& Gamble Attorney Docket No. 11564). For example, a package
containing from one to 12, or more, outer covers, together with one
or a plurality of associated inserts, may be assembled and sold
together as packaged. The respective outer cover(s) and inserts in
a package may have matching/complementary fastening systems,
orientation indicia and/or alignment indicia as described
herein.
[0111] For such an article of commerce it may be desirable to
determine a ratio of inserts to outer covers suitable to constitute
a set of convenient numbers of outer covers and inserts,
respectively. For example, it may be deemed suitable to include
approximately a half day or day's supply of inserts for each outer
cover included in the set. Thus, for example, the article of
commerce may include inserts and outer covers in a ratio of inserts
to outer covers of 1:1, 2:1, 3:1, 4:1, 5:1 or even 6:1.
Accordingly, for example, a package associating a set may include
one outer cover and 1, 2, 3, 4, 5 or 6 inserts; two outer covers
and 2, 4, 6, 8, 10 or 12 inserts; three outer covers and 3, 6, 9,
12, 15 or 18 inserts, and so on. For a "starter" set for certain
consumers such as first-time purchasers, or in other circumstances,
it may be desirable for a package to contain from 2 to 14 outer
covers--which may correspond roughly to from one day's to one
week's supply of clean outer covers available before laundering
becomes necessary.
Bending Stiffness Test
[0112] Peak Bending Force and Total Stiffness are measured using a
constant rate of extension tensile tester with computer interface
(a suitable instrument is an MTS Alliance under TestWorks 4
software, as available from MTS Systems Corp., Eden Prairie, Minn.)
using a load cell for which the forces measured are within 10% and
90% of the limit of the cell. A plunger blade 600, shown in FIG. 5
(front view) and FIG. 6 (side view), is used for the upper movable
test fixture. Base support platforms 700, shown in FIG. 7, are used
as the lower stationary test fixture. All testing is performed in a
conditioned room maintained at about 23.degree. C..+-.2.degree. C.
and about 50%.+-.2% relative humidity.
[0113] Components of the plunger 600 are made of a light weight
material such as aluminum to maximize the available load cell
capacity. The shaft 601 is machined to fit the tensile tester and
has a locking collar 602 to stabilize the plunger and maintain
alignment orthogonal to base support platforms 704. The blade 603,
is 115 mm long 608 by 65 mm high 607 by 3.25 mm wide 609, and has a
material contact edge with a continuous radius of 1.625 mm. The
bracket 604 is fitted with set screws 605 that are used to level
the blade and a main set screw 606 to firmly hold it in place after
adjustment.
[0114] The bottom fixture 700 is attached to the tensile tester
with the shaft 701 and locking collar 702. Two horizontally movable
support platforms 704 are mounted on a rail 703. Each test surface
705 is 85 mm wide 706 by 115 mm long (into plane of drawing) and
made of polished stainless steel so as to have a minimal
coefficient of friction. Each platform has a digital position
monitor 708 which reads the individual platform positions, and set
screws 707 to lock their position after adjustment. The two
platforms 704 are square at the gap edge and the plate edges should
be parallel front to back. The two platforms form a gap 709 with an
adjustable gap width 710.
[0115] Accurately (.+-.0.02 mm) align the plunger blade 603 so that
it is orthogonal to the top surface of the support platforms 704
and exhibits no skew relative to their gap edges. Using the
position monitors 708, accurately set the gap 710 to 13.25.+-.0.02
mm between the two gap edges of the support platforms 704, with the
plunger blade 603 accurately (.+-.0.02 mm) centered in the gap. Set
the gauge length from the bottom of the plunger blade 603 to the
top surface of the support platform 704 to 15 mm. Program the
tensile tester to perform a compression test, collecting force and
extension data at an acquisition rate of 200 Hz as the crosshead
lowers at a rate of 500 mm/min for a total distance of 35 mm.
[0116] Precondition samples at about 23.degree. C..+-.2.degree. C.
and about 50%.+-.2% relative humidity for 2 hours prior to testing.
The outer cover article is opened and placed with the wearer-facing
surface facing downward. Using scissors remove the leg elastics,
such that the article can be laid flat. Identify and mark the
center of a sampling region which is representative of the material
making up the majority of the article, ensuring that it is free of
seams, snaps, labels, etc. The sampling region may often be located
toward the back/crotch region of the article. With a hydraulic
press and cutting die (76.2 mm square.+-.0.1 mm and 8 mm deep), cut
a specimen centered on this mark through all the layers of the
article, with the specimen's cut edges parallel and perpendicular
to the longitudinal and lateral axis of the article.
[0117] Place the all layers of the specimen flat onto the surface
of the support platform 704 over the gap 709 with the wearer-facing
surface facing upward. Arrange the specimen 1009 under the blade
603 such that about 1/3 of the specimen is to the right of the
blade and 2/3 to the left. The specimen is placed such that the
direction corresponding to the lateral axis of the absorptive
article it was harvested from is parallel to the length of the
blade. Zero the load cell; start the tensile tester and the data
acquisition. Program the software to calculate the maximum Peak
Bending Force (N) from the constructed force (N) verses extension
(m) curve, and record as "Lateral face-up".
[0118] Remove the specimen from the gap 709, keeping the
wearer-facing side up. Rotate the specimen 90.degree. clockwise,
and arrange the specimen under the blade 603 such that about 1/3 of
the specimen is to the right of the blade and 2/3 to the left,
exposing a fresh area of the specimen for testing. Zero the load
cell; start the tensile tester and the data acquisition. Record the
maximum Peak Bending Force (N) as "Longitudinal face-up".
[0119] Remove the specimen from the gap 709, keeping the
wearer-facing side up. Rotate the specimen 90.degree.
counter-clockwise, and turn the specimen over from left to right,
so that the wearer-facing surface is facing downward. Arrange the
specimen under the blade 603 such that about 1/3 of the specimen is
to the right of the blade and 2/3 to the left, exposing a fresh
area of the specimen for testing. Zero the load cell; start the
tensile tester and the data acquisition. Record the maximum Peak
Bending Force (N) as "Lateral face-down".
[0120] Remove the specimen from the gap 709, keeping the
wearer-facing side down. Rotate the specimen 90.degree.
counter-clockwise, and arrange the specimen under the blade 603
such that about 1/3 of the specimen is to the right of the blade
and 2/3 to the left, exposing a fresh area of the specimen for
testing. Zero the load cell; start the tensile tester and the data
acquisition. Record the maximum Peak Bending Force (N) as
"Longitudinal face-down".
[0121] Calculate the Total Stiffness for a specimen by summing the
"Lateral face-up", "Longitudinal face-up", "Lateral face-down" and
"Longitudinal face-down" forces. Report the Total Stiffness to the
nearest 0.001 N. Repeat the test and record the results for 10
samples. Calculate and report the average Total Stiffness.
[0122] 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."
[0123] Every document cited herein, including any cross-referenced
or related patent or application, is hereby incorporated herein by
reference in its entirety unless expressly excluded or otherwise
limited. The citation of any document is not an admission that it
is prior art with respect to any invention disclosed or claimed
herein or that it alone, or in any combination with any other
reference or references, teaches, suggests or discloses any such
invention. Further, to the extent that any meaning or definition of
a term in this document conflicts with any meaning or definition of
the same term in a document incorporated by reference, the meaning
or definition assigned to that term in this document shall
govern.
[0124] While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention. It is therefore intended that the appended claims cover
all such changes and modifications, and that nothing in the
foregoing description or the figures, but rather, only the appended
claims, limit the scope of the invention.
* * * * *
References