U.S. patent application number 10/456463 was filed with the patent office on 2003-10-23 for wearable article having a wetness sensation member.
This patent application is currently assigned to The Procter & Gamble Company. Invention is credited to Allen, Patrick J., Carlin, Edward P., Roe, Donald C..
Application Number | 20030199845 10/456463 |
Document ID | / |
Family ID | 25540685 |
Filed Date | 2003-10-23 |
United States Patent
Application |
20030199845 |
Kind Code |
A1 |
Roe, Donald C. ; et
al. |
October 23, 2003 |
Wearable article having a wetness sensation member
Abstract
A wearable disposable absorbent article useful for facilitating
toilet training. The wearable disposable absorbent article includes
a wetness sensation member having a permeable body-facing layer and
an impermeable layer disposed between the permeable layer and an
absorbent core in a face-to-face arrangement with the permeable
layer. During insults of urine, the permeable layer allows urine to
penetrate in the z-direction and provides a medium for the flow of
urine in the x-y plane via wicking. The impermeable layer prevents
the urine from passing completely through the wetness sensation
member in the z direction and supports the movement of the urine in
an x-y plane to enhance the wearer's awareness that urination has
occurred by increasing the wetted area contacting the wearer's
skin. The wetness sensation member preferably is held in close
contact with a wearer's skin during use.
Inventors: |
Roe, Donald C.; (West
Chester, OH) ; Allen, Patrick J.; (Cincinnati,
OH) ; Carlin, Edward P.; (Maineville, OH) |
Correspondence
Address: |
THE PROCTER & GAMBLE COMPANY
INTELLECTUAL PROPERTY DIVISION
WINTON HILL TECHNICAL CENTER - BOX 161
6110 CENTER HILL AVENUE
CINCINNATI
OH
45224
US
|
Assignee: |
The Procter & Gamble
Company
|
Family ID: |
25540685 |
Appl. No.: |
10/456463 |
Filed: |
June 6, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10456463 |
Jun 6, 2003 |
|
|
|
09994461 |
Nov 26, 2001 |
|
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Current U.S.
Class: |
604/385.101 ;
604/378 |
Current CPC
Class: |
A61F 13/53717 20130101;
A61F 13/82 20130101; A61F 2013/425 20130101; A61F 13/53704
20130101; A61F 13/84 20130101; A61F 13/495 20130101; A61F 13/53747
20130101; A61F 13/42 20130101; A61F 13/4942 20130101 |
Class at
Publication: |
604/385.101 ;
604/378 |
International
Class: |
A61F 013/15; A61F
013/20 |
Claims
What is claimed is:
1. A wearable disposable absorbent article for wearing about a
lower torso of a wearer and having a first waist region, a second
waist region, and a crotch region interposed therebetween, the
wearable disposable absorbent article comprising: a backsheet; a
topsheet joined to the backsheet; an absorbent core disposed
intermediate the backsheet and the topsheet; and a wetness
sensation member covering a portion of the absorbent core and
including a permeable body-facing layer not formed by a portion of
the topsheet and an impermeable layer disposed between the
permeable body-facing layer and the absorbent core in a
face-to-face arrangement with the permeable body-facing layer, no
portion of the permeable body-facing layer extending longitudinally
or transversely beyond the impermeable layer; wherein urine
deposited by the wearer onto the wetness sensation member can
penetrate through the permeable body-facing layer in a z direction
away from the wearer to the impermeable layer and the impermeable
layer prevents the urine from passing completely through the
wetness sensation member in the z direction and supports the
movement of the urine in an x-y plane such that the wearer's
awareness of urination is enhanced.
2. The wearable disposable absorbent article of claim 1 wherein the
wetness sensation member is elastically foreshortened.
3. The wearable disposable absorbent article of claim 1 wherein the
impermeable layer of the wetness sensation member is elastically
foreshortened.
4. The wearable disposable absorbent article of claim 1 wherein the
topsheet is elastically foreshortened and the wetness sensation
member is attached to the topsheet.
5. The wearable disposable absorbent article of claim 1 wherein the
impermeable layer is disposed in a face-to-face arrangement with
the absorbent core.
6. A wearable disposable absorbent article for wearing about a
lower torso of a wearer and having a longitudinal axis, a first
waist region, a second waist region, and a crotch region interposed
therebetween, the wearable disposable absorbent article comprising:
a backsheet; a topsheet joined to the backsheet; an absorbent core
disposed intermediate the backsheet and the topsheet; and a
plurality of wetness sensation members disposed parallel to and
spaced apart from the longitudinal axis, each of the wetness
sensation members covering a portion of the absorbent core and
including a permeable body-facing layer not formed by a portion of
the topsheet and an impermeable layer disposed between the
permeable body-facing layer and the absorbent core in a
face-to-face arrangement with the permeable body-facing layer, no
portion of the permeable body-facing layer extending longitudinally
or transversely beyond the impermeable layer; wherein urine
deposited by the wearer onto the wetness sensation member can
penetrate through the permeable body-facing layer in a z direction
away from the wearer to the impermeable layer and the impermeable
layer prevents the urine from passing completely through the
wetness sensation member in the z direction and supports the
movement of the urine in an x-y plane such that the wearer's
awareness of urination is enhanced.
7. The wearable disposable absorbent article of claim 6 wherein
each of the wetness sensation members is elastically
foreshortened.
8. The wearable disposable absorbent article of claim 6 wherein the
impermeable layer of each of the wetness sensation members is
elastically foreshortened.
9. The wearable disposable absorbent article of claim 6 wherein the
topsheet is elastically foreshortened and the wetness sensation
members are attached to the topsheet.
10. The wearable disposable absorbent article of claim 6 wherein
the impermeable layer of each of the wetness sensation members is
disposed in a face-to-face arrangement with the absorbent core.
11. A wearable disposable absorbent article for wearing about a
lower torso of a wearer and having a longitudinal axis, a first
waist region, a second waist region, and a crotch region interposed
therebetween, the wearable disposable absorbent article comprising:
a backsheet; a topsheet joined to the backsheet and having a
body-facing surface; an absorbent core disposed intermediate the
backsheet and the topsheet; and at least one wetness sensation
member disposed on a portion of the body-facing surface of the
topsheet covering a portion of the absorbent core, the wetness
sensation member including a permeable body-facing layer and an
impermeable layer disposed between the permeable body-facing layer
and the topsheet in a face-to-face arrangement with the permeable
body-facing layer; wherein urine deposited by the wearer onto the
wetness sensation member can penetrate through the permeable
body-facing layer in a z direction away from the wearer to the
impermeable layer and the impermeable layer prevents the urine from
passing completely through the wetness sensation member in the z
direction and supports the movement of the urine in an x-y plane
such that the wearer's awareness of urination is enhanced.
12. The wearable disposable absorbent article of claim 11 wherein
the wetness sensation member is elastically foreshortened.
13. The wearable disposable absorbent article of claim 11 wherein
the impermeable layer of the wetness sensation member is
elastically foreshortened.
14. The wearable disposable absorbent article of claim 11 wherein
the topsheet is elastically foreshortened and the wetness sensation
member is attached to the topsheet.
15. The wearable disposable absorbent article of claim 11 wherein
the wetness sensation member extends along the longitudinal axis
from the first waist region to the second waist region, the wetness
sensation member further comprises a first end, a second end
opposite the first end, and a center disposed therebetween, and the
first end, second end and center of the wetness sensation member
are discretely attached to the body-facing surface of the topsheet
in the first waist region, the second waist region, and the crotch
region, respectively.
16. The wearable disposable absorbent article of claim 11 wherein
the wetness sensation member extends along the longitudinal axis
from the first waist region to the second waist region, the wetness
sensation member further comprises a first end, a second end
opposite the first end, and a center disposed therebetween, the
first end is discretely attached to the body-facing surface of the
topsheet in the first waist region, and a portion of the wetness
sensation member between the center and the second end is uniformly
attached to the body-facing surface of the topsheet.
17. The wearable disposable absorbent article of claim 11 wherein
the wetness sensation member extends along the longitudinal axis
from the first waist region to the crotch region, the wetness
sensation member further comprises a first end and a second end
opposite the first end, and the first end and the second end of the
wetness sensation member are discretely attached to the body-facing
surface of the topsheet in the first waist region and the crotch
region, respectively.
18. The wearable disposable absorbent article of claim 11 wherein
the impermeable layer is disposed in a face-to-face arrangement
with the absorbent core.
19. The wearable disposable absorbent article of claim 11 wherein
no additional impermeable layer is disposed between the impermeable
layer and the absorbent core.
20. A wearable disposable absorbent article for wearing about a
lower torso of a wearer and having a longitudinal axis, a first
waist region, a second waist region, and a crotch region interposed
therebetween, the wearable disposable absorbent article comprising:
a backsheet; a topsheet joined to the backsheet and having a
body-facing surface; an absorbent core disposed intermediate the
backsheet and the topsheet; impermeable barrier leg cuffs disposed
on the body-facing surface of the topsheet parallel to the
longitudinal axis; and wetness sensation members integrated with
the barrier leg cuffs such that a portion of each of the barrier
leg cuffs covering a portion of the absorbent core forms an
impermeable layer of each of the respective wetness sensation
members, each of the wetness sensation members also including a
permeable body-facing layer disposed in a face-to-face arrangement
with the impermeable layer; wherein urine deposited by the wearer
onto each of the wetness sensation members can penetrate through
the permeable body-facing layer in a z direction away from the
wearer to the impermeable layer and the impermeable layer prevents
the urine from passing completely through the wetness sensation
member in the z direction and supports the movement of the urine in
an x-y plane to enhance the wearer's awareness that urination has
occurred.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a division of U.S. application Ser. No.
09/994,461, filed on Nov. 26, 2001 in the name of Roe et al.,
confirmation number 9503, which application is hereby incorporated
in its entirety herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention is directed to hygienic absorbent articles,
such as diapers, training pants and the like. Particularly, the
invention is directed to training pants facilitating the toilet
training process.
[0003] Absorbent articles are well known in the art. These articles
typically have an absorbent core held or positioned in proximity to
the body of a wearer during use by a fastening system in order to
capture and absorb bodily exudates discharged from the wearer.
Typical absorbent articles include a topsheet facing the wearer,
which permits fluid exudates to pass through, and a backsheet,
which prevents the exudates from escaping from the absorbent
article.
[0004] Disposable absorbent articles such as diapers are designed
to absorb and contain bodily waste in order to prevent soiling of
the body and clothing of the wearer. The disposable diapers
typically comprise a single design available in different sizes to
fit a variety of wearers ranging from newborns to toddlers
undergoing toilet training. The design of the diaper typically
affects performance, such as, ability to absorb and contain bodily
waste. The size of the diaper typically affects fit, for example,
the size of the diaper waist opening, the size of the openings
around the thighs, and the length or "pitch" of the diaper.
[0005] The toilet training stage may be referred to as the "point
of exit" as toddlers typically leave the product category once
training is successfully completed. The age at which children are
toilet trained in "developed" countries has increased steadily over
the past several decades and is now in the range of about 24-48
months. One reason toilet training has become delayed is due to
significant technical improvements in diaper dryness and comfort.
In modern diapers, the child has dry skin even after one or more
urinations. As a result, the child feels little or no discomfort
and often may not even be aware that they have urinated.
[0006] Many parents have the child wear cotton training pants or
underwear during toilet training so the child feels discomfort
following urination in their "pants". It is believed that such
discomfort assists with learning or provides motivation to learn
proper toilet training. Cotton training pants leave the skin wet
and, due to their high breathability, promote evaporative cooling
of the skin, further enhancing discomfort. The current tradeoff in
this approach, however, is that cotton training pants have poor
urine containment leading to wet clothing and often times, wet
surroundings e.g. carpeting, furniture, etc. Clearly there is a
need to provide a training signal to the toilet training child
while preventing urine leakage and unnecessary changes of
clothing.
[0007] Thus, it would be desirable to provide a wearable article
that can facilitate toilet training by enhancing a wearer's
awareness that urination has occurred while at the same time
providing the protection of an absorbent article, preventing
soiling of the wearer's clothing and surroundings. Particularly, it
would be desirable to provide such a wearable article providing an
effective signal of urination by ensuring that the wearer feels an
uncomfortable wetness sensation resulting from urination.
SUMMARY OF THE INVENTION
[0008] In order to solve one or more of the problems found in the
art, a wearable article, such as an absorbent article, is provided
with a wetness sensation member held in close contact with a
wearer's skin during use that enhances the wearer's awareness that
a discharge of bodily exudates, such as urine, has occurred. The
wetness sensation member comprises a permeable layer and an
impermeable layer disposed in a face-to-face arrangement with the
permeable layer. The wetness sensation member is typically in
proximity to the wearer's urethra so that once the wearer urinates
wetting an area of the wetness sensation member, the urine
penetrates through the thickness of the permeable layer in the
z-direction to the impermeable layer which provides a path of least
resistance supporting the flow of urine in the x-y plane. This
enables the urine to wet a large area of the wetness sensation
member before being absorbed into the absorbent core. The wetness
sensation member is held in contact with the wearer's skin during
use thereby enhancing the wearer's awareness that urination has
occurred.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] While the specification concludes with claims particularly
pointing out and distinctly claiming the subject matter which is
regarded as forming the present invention, it is believed that the
invention will be better understood from the following description
which is taken in conjunction with the accompanying drawings in
which like designations are used to designate substantially
identical elements, and in which:
[0010] FIG. 1 is a plan view of a disposable diaper.
[0011] FIG. 2 is a cross sectional view of a wetness sensation
member according to the present invention.
[0012] FIG. 3a is a plan view of a diaper having a wetness
sensation member disposed on a body-facing surface.
[0013] FIG. 3b is a cross sectional view of the diaper shown in
FIG. 3a illustrating the layers of the wetness sensation
member.
[0014] FIG. 4 is an isometric view of a pull-on diaper illustrating
the attachment of the wetness sensation member.
[0015] FIG. 5a is a plan view of a diaper having a wetness
sensation member integrated with to the topsheet.
[0016] FIG. 5b is a cross sectional view of the diaper illustrated
in FIG. 5a.
[0017] FIG. 6a is a plan view of a diaper having two wetness
sensation members integrated with the topsheet and disposed
parallel to and spaced apart from the longitudinal axis with an
elongated slit opening interposed therebetween.
[0018] FIG. 6b is a cross sectional view of the diaper illustrated
in FIG. 6a.
[0019] FIG. 7a is a plan view of a diaper having a Z-folded
topsheet with two wetness sensation members integrated with the
topsheet and disposed in the Z-folds in the topsheet.
[0020] FIG. 7b is a cross sectional view of the diaper illustrated
in FIG. 7a.
[0021] FIG. 8a is a plan view of a diaper with barrier leg cuffs
including wetness sensation members integrated with the leg
cuffs.
[0022] FIG. 8b is a cross sectional view of the diaper illustrated
in FIG. 8a.
DETAILED DESCRIPTION OF THE INVENTION
[0023] While this specification concludes with claims particularly
pointing out and distinctly claiming that which is regarded as the
invention, it is anticipated that the invention can be more readily
understood through reading the following detailed description of
the invention and study of the included drawings.
[0024] The present invention provides a wearable article having a
wetness sensation member that increases a wearer's awareness that
urination has occurred by causing the urine discharged from the
body of the wearer to wet an effective area of the member held in
close contact with the wearer's skin during use. The wetness
sensation member is equally applicable to wearable articles such as
disposable absorbent articles including training pants,
incontinence briefs, incontinence undergarments, absorbent inserts,
diaper holders and liners, feminine hygiene garments, and the like.
One embodiment of an absorbent article of the present invention is
a unitary disposable absorbent article, such as the disposable
diaper 20, shown in FIG. 1. However, preferably, the present
invention is applicable to disposable training pants and pull-on
diapers designed to facilitate toilet training.
[0025] Definitions:
[0026] As used herein, the following terms have the following
meanings:
[0027] "Absorbent article" refers to devices that absorb and
contain liquid, and more specifically, refers to devices that are
placed against or in proximity to the body of the wearer to absorb
and contain the various exudates discharged from the body.
[0028] "Longitudinal" is a direction running parallel to the
maximum linear dimension of the article and includes directions
within +45.degree. of the longitudinal direction.
[0029] The "lateral" or "transverse" direction is orthogonal to the
longitudinal direction.
[0030] The "z-direction" is orthogonal to both the longitudinal and
transverse directions.
[0031] The "x-y plane refers to the plane congruent with the
longitudinal and transverse directions.
[0032] The term "disposable" is used herein to describe absorbent
articles that generally are not intended to be laundered or
otherwise restored or reused as an absorbent article (i.e., they
are intended to be discarded after a single use and, preferably, to
be recycled, composted or otherwise disposed of in an
environmentally compatible manner).
[0033] As used herein, the term "disposed" is used in the context
of structural elements to mean that an element(s) is formed (joined
and positioned) in a particular place or position as a unitary
structure with other elements or as a separate element joined to
another element.
[0034] As used herein, the term "joined" encompasses configurations
whereby an element is directly secured to another element by
affixing the element directly to the other element, and
configurations whereby an element is indirectly secured to another
element by affixing the element to intermediate member(s) which in
turn are affixed to the other element.
[0035] A "unitary" absorbent article refers to absorbent articles
which are formed of separate parts united together to form a
coordinated entity so that they do not require separate
manipulative parts like a separate holder and liner.
[0036] As used herein, the term "diaper" refers to an absorbent
article generally worn by infants and incontinent persons about the
lower torso.
[0037] As used herein, the term "impermeable" generally refers to
articles and/or elements that are not penetrative by fluid in the
liquid state through the entire Z-directional thickness of the
article under pressure of 0.14 lb/in.sup.2 or less. Preferably, the
impermeable article or element is not penetrative by fluid in the
liquid state under pressures of 0.5 lb/in.sup.2 or less. More
preferably, the impermeable article or element is not penetrative
by fluid in the liquid state under pressures of 1.0 lb/in.sup.2 or
less.
[0038] FIG. 1 is a plan view of the diaper 20 in its flat out,
uncontracted state (i.e., without elastic induced contraction) with
portions of the structure being cut away to more clearly show the
underlying structure of the diaper 20 and with the portion of the
diaper 20 which contacts the wearer facing the viewer. The diaper
20 includes a longitudinal axis 42 and a transverse axis 44. One
end portion 36 of the diaper 20 is configured as a first waist
region of the diaper 20. The opposite end portion 38 is configured
as a second waist region of the diaper 20. An intermediate portion
37 of the diaper 20 is configured as a crotch region, which extends
longitudinally between the first and second waist regions 36 and
38. The waist regions 36 and 38 generally comprise those portions
of the diaper 20 which, when worn, encircle the waist of the
wearer. The waist regions 36 and 38 may include elastic elements
such that they gather about the waist of the wearer to provide
improved fit and containment. The crotch region 37 is that portion
of the diaper 20 which, when the diaper 20 is worn, is generally
positioned between the legs of the wearer.
[0039] The diaper 20 preferably comprises a liquid pervious
topsheet 24, a liquid impervious backsheet 26, and an absorbent
core 28 encased between the topsheet 24 and the backsheet 26. The
topsheet 24 may be fully or partially elasticated or may be
foreshortened so as to provide a void space between the topsheet 24
and the core 28. Exemplary structures including elasticized or
foreshortened topsheets are described in more detail in U.S. Pat.
No. 4,892,536 issued to DesMarais et al. on Jan. 9, 1990 entitled
"Absorbent Article Having Elastic Strands"; U.S. Pat. No. 4,990,147
issued to Freeland on Feb. 5, 1991 entitled "Absorbent Article With
Elastic Liner For Waste Material Isolation"; U.S. Pat. No.
5,037,416 issued to Allen et al. on Aug. 6, 1991 entitled
"Disposable Absorbent Article Having Elastically Extensible
Topsheet"; and U.S. Pat. No. 5,269,775 issued to Freeland et al. on
Dec. 14, 1993 entitled "Trisection Topsheets For Disposable
Absorbent Articles and Disposable Absorbent Articles Having Such
Trisection Topsheets".
[0040] The diaper 20 may include a fastener such as a hook and loop
type fastening system 40 including at least one engaging component
(male fastening component) and at least one landing zone (female
fastening component). The diaper 20 may also include such other
features as are known in the art including leg cuffs, front and
rear ear panels, waist cap features, elastics and the like to
provide better fit, containment and aesthetic characteristics. Such
additional features are well known in the art and are described in
U.S. Pat. No. 3,860,003; and U.S. Patent No. 5,151,092.
[0041] In addition, the present invention may be suitable for other
diaper embodiments including those disclosed in U.S. Pat. No.
6,010,491 titled "Viscous Fluid Bodily Waste Management Article"
issued Jan. 4, 2000; U.S. Patent No. 5,873,870 titled "Fit And
Sustained Fit Of A Diaper Via Chassis And Core Modifications"
issued Feb. 23, 1999; U.S. Patent No. 5,897,545 titled "Elastomeric
Side Panel for Use with Convertible Absorbent Articles" issued Apr.
27, 1999; U.S. Pat. No. 5,904,673 titled "Absorbent Article With
Structural Elastic-Like Film Web Waist Belt" issued May 18, 1999;
U.S. Pat. No. 5,931,827 titled "Disposable Pull On Pant" issued
Aug. 3, 1999; U.S. Pat. No. 5,977,430 titled "Absorbent Article
With Macro-Particulate Storage Structure" issued Nov. 2, 1999 and
U.S. Pat. No. 6,004,306 titled "Absorbent Article With
Multi-Directional Extensible Side Panels" issued Dec. 21, 1999.
[0042] An exemplary wetness sensation member according to the
present invention is shown in FIG. 2. The wetness sensation member
50 comprises a permeable layer 52 and an impermeable layer 54
disposed opposite the permeable layer 52. The impermeable layer is
preferably impermeable to fluid in the liquid state but permeable
to vapor so that it is breathable. The wetness sensation member 50
according to the present invention preferably comprises a permeable
body-facing layer (upper layer) and an impermeable layer (lower
layer) opposite the body facing layer.
[0043] During insults of urine, the permeable layer 52 allows urine
to penetrate in the z-direction and also provides a medium for the
flow of urine in the x-y plane via wicking. The impermeable layer
supports the flow of liquid between the permeable and impermeable
layers and retains the liquid thereby expanding the wetted area of
the wetness sensation member, which is held in as intimate and
continuous contact as possible with the wearer's skin. The
combination of penetration and flow enables the urine to spread out
and effectively wet a large area before being absorbed into the
core, which in turn maximizes the wetness signal experienced by the
wearer.
[0044] Exemplary permeable layers suitable for use in the wetness
sensation members of the present invention include nonwovens,
foams, woven materials, etc. The permeable layer is preferably
hydrophilic and capable of retaining at least 4-12 g/g urine
against gravity. Exemplary impermeable layers suitable for use in
the wetness sensation members of the present invention include
polyolefinic films, microporous or breathable films, other films,
and hydrophobic nonwovens having a hydrohead greater than about
0.14 lb/in.sup.2. Suitable hydrophobic nonwovens include SM
(spunbond meltblown), SMS (spunbond meltblown spunbond), and SMMS
(spunbond meltblown meltblown spunbond) composites.
[0045] The benefits of the wetness sensation member can be shown by
comparison of the strikethrough time for a given sample of
temperature sensation member and a topsheet material. Strikethrough
time is the time required for a given volume of surface applied
liquid to enter a given material into an underlying absorbent core.
The testing is performed according to Topsheet Strikethrough Time
Test Procedure provided. The testing was performed comparing a
wetness sensation member composed of a 18 g/m.sup.2 spunbond
nonwoven laminated to a 20 g/m.sup.2 SMMS nonwoven via 6 g/m.sup.2
adhesive to a topsheet material composed of 18 gsm Spunbond
nonwoven. The results of the testing revealed the wetness sensation
member to have a strikethrough time on the average about 3.4 times
the strikethrough time of the topsheet material. The results of the
testing are illustrated in the table below.
1 Strikethrough Time Test Results Wetness Topsheet Sensation Only
(sec) Member (sec) 2.42 6.26 2.44 8.93 2.24 7.52 2.17 7.80 2.11
8.05 2.27 8.16 2.28 7.53 2.54 7.76 2.36 8.12 2.09 8.56 1.98 6.27
Average 2.26 7.72
[0046] Topsheet Strikethrough Time Test Procedure
[0047] Perform the analysis in a room conditioned at 73+2.degree.
F. and 50+2% relative humidity. Set up a ring stand to support a
clean, automatic filling buret and a separatory funnel so that the
tip of the buret extends into the separatory funnel. Position the
Plexiglas base plate of the strike-through/rewet apparatus on the
base of the ring stand beneath the tip of the separatory funnel so
that the tip of the funnel will be 1 1/8+{fraction (1/32)} inch
above the top of the Plexiglas base plate. Using Tygon tubing,
connect the aspirator bottle to the automatic filling buret. Place
a magnetic stirring bar in the aspirator bottle. Fill the bottle
with synthetic urine test solution (see Solution). Turn on the
motor to the magnetic stirrer and keep it on for the duration of
the testing. After the test solution has stirred for a minimum of
30 minutes, rinse the buret at least 3 times with the solution
before filling to the zero mark. Make sure the buret tip is filled
also. Place 15 ml of test solution in the separatory funnel and
drain to wet the walls of the funnel. Repeat for a total of two
times. The buret must be rinsed at least three times and the walls
of the separatory funnel wetted twice, using these techniques,
before the beginning of each testing session. These preparation
steps are performed only after the test solution has stirred at
least 30 minutes.
[0048] All testing is done with the test solution in the aspirator
bottle under agitation.
[0049] NOTE: Keeping the buret full of the test solution when not
in use will prevent it from becoming dirty on the inside. Dirty
glassware, including the buret, separatory funnel, and
strikethrough plate will not drain properly. Once a week, or more
often if necessary, clean the buret, the separatory funnel, and the
strikethrough plate thoroughly with an Alconox solution. (To
prepare Alconox solution, dissolve about eight grams of Alconox in
one liter of warm water.) Clean the strikethrough plate cavity, the
bottom of the strikethrough plate, the plastic points at the bottom
of the cavity, and around and between the electrodes with Alconox
solution and a pipe cleaner. Rinse the buret, the separatory
funnel, and the strikethrough plate several times with distilled
water and then with the test solution before using. All Alconox
must be removed before using for further testing.
[0050] The amount of test solution used in the strikethrough/rewet
test sequence is a characteristic of the lot of Eaton-Dikeman #939
filter paper being used. For each issue of Eaton-Dikeman #939
filter paper provided, the total volume of test solution to be used
for the strikethrough/rewet sequence will be specified in terms of
an "X-loading" factor, which represents the ml of test solution to
be used per gram of filter paper stack weight.
[0051] To determine the total solution volume to be used in
milliliters, multiply the "X-loading" factor by the filter paper
stack weight; i.e., if the "X-loading" for a lot of paper is 3.90
ml/g and filter paper stack weight determined was 4.35 g, the total
test solution volume required is 3.90.times.4.35=17.0 ml.
[0052] Place the topsheet sample to be tested on a previously
weighted 4 in..times.4 in. three sheet filter paper stack with the
side of the topsheet, which will be next to the baby facing up.
Place the total sample filter paper stack and topsheet on the dry
Plexiglas base plate with the fabric facing up. (Plexiglas base
plate and strikethrough plate must be dried between tests with a
Bounty towel.) Center the dry strikethrough plate on the topsheet
and center the entire assembly under the stem of the separatory
funnel with the tip of the funnel 1 1/8+{fraction (1/32)} in. above
the top of the Plexiglas base plate.
[0053] Strikethrough Time Measurement
[0054] With the separatory funnel stopcock closed, discharge 5.0 ml
of test solution from the buret into the funnel.
[0055] With the strikethrough/rewet apparatus timer power ON, the
timer set to zero, and the wires connected to the strikethrough
plate, start the test measurement by suddenly opening the funnel
stopcock and discharging the 5.0 ml into the strikethrough plate
sample cavity. The initial liquid discharge will start the timer
and after the liquid has emptied from the cavity, the timer will
shut off. After the timer has shut off, record the strikethrough
time to the nearest 0.01-second. Do not remove the strikethrough
plate, sample pad, etc. from under the separatory funnel. Close the
separatory stopcock.
[0056] The ability of a wetness sensation member to support the
flow of liquid in the x-y plane can be measured by its wicking
capability. The wicking capability of the wetness sensation member
was measured according to INDA Standard test: IST 10.1 (95)
Paragraph 10. Liquid Wicking Rate. The test is the measure of the
time in seconds for liquid to wick vertically 1.0 inch. The results
of the test, summarized in the table below, reveal that wetness
sensation member can support vertical wicking of 1.0 inch in an
average time of 6.8 seconds whereas the topsheet material was
incapable of reaching the 1.0-inch level of vertical wicking.
2 Vertical Wicking Test Results Wetness Sensation Topsheet Only
Member (seconds to 1") (seconds to 1") N/A 8 N/A 7 N/A 7 N/A 6 N/A
7 N/A 6 N/A 6 N/A 7 N/A 7 N/A 7 Average N/A 6.80
[0057] The wetness sensation member according to the present
invention may be arranged in an absorbent article in a variety of
configurations. In addition, absorbent articles may include a
single wetness sensation member or a plurality of wetness sensation
members. In any event, the wetness sensation member(s) are
preferably a part of, or attached to, an element or web, such as a
topsheet, which is reliably held against the skin of the wearer. In
addition, the wetness sensation member(s) are preferably positioned
within the absorbent article to enhance the likelihood of being
wetted with urine.
[0058] An exemplary embodiment of a wetness sensation member 50
disposed with the topsheet 24 is illustrated in FIGS. 3a and 3b. As
shown, the wetness sensation member 50 comprises a separate
composite member attached to the topsheet 24. The wetness sensation
member 50 comprises a permeable body-facing layer 52, and
impermeable layer 54 opposite the body-facing layer. For this
embodiment, the wetness sensation member 50 is preferably
configured and assembled to enhance the likelihood of making
contact with the wearer's skin during use. For instance, the
impermeable layer 54 of the wetness sensation member 50 may be
bonded to the topsheet 24 using adhesives, ultrasonic bonds, radio
frequency bonds, or other suitable means while either the topsheet
24 or the wetness sensation member 50 is elastically foreshortened
to deflect the member 50 towards the wearer's skin.
[0059] In an embodiment illustrated in FIG. 4, a wetness sensation
member 50 comprising a separate composite member is disposed on the
topsheet 24 of a pull-on type diaper. For this embodiment, the
wetness sensation member 50 has elastic properties and includes a
first longitudinal end 70 attached to the first waist region 36 and
a second longitudinal end 72 attached to the second waist region
38. In addition, a center portion 74 of the member 50 is preferably
attached to the crotch region 37 of the diaper 20 in order to
stabilize the member and facilitate fitting the article to the
wearer, prevent interference with bowel movements and ensure good
contact with the wearer's skin.
[0060] In an alternate embodiment shown in FIGS. 5a and 5b, the
impermeable layer 54 of the wetness sensation member 50 is attached
to the inner surface of the topsheet 24 such that at least a
portion of the topsheet 24 forms the permeable layer 52 of the
wetness sensation member 50. For this embodiment, the topsheet 24
is preferably elastically foreshortened to deflect the wetness
sensation member 50 into contact with the wearer's skin.
Alternatively, this embodiment may include a topsheet that is
shorter in length than the backsheet, having the longitudinal ends
of the topsheet contiguous with the longitudinal ends of the
backsheet so that as the diaper is fitted around the wearer, the
topsheet is forced into contact with the wearer's skin.
[0061] Regardless of the specific construction, the position and/or
structure of the wetness sensation member 50 should enable the
member to be wetted with urine and thereafter held in contact with
the wearer's skin. The wetness sensation member is preferably
disposed in at least a portion of the crotch region 37 of the
diaper 20, centered about the longitudinal centerline 42. The
wetness sensation member 50 may extend over a portion of the
disposable absorbent article spanning less than one half of the
length of the article or else extend a substantial part of the
article spanning more than one half the length of the article.
Furthermore, the wetness sensation member 50 is preferably
coordinated with the wearer's urethra in order to cover the area in
which urine initiates contact with the disposable absorbent
article.
[0062] Absorbent articles according to the present invention may
include a plurality of wetness sensation members disposed on the
body-facing surface of the article. An example of an embodiment
providing a plurality of wetness sensation members is shown in
FIGS. 6a and 6b. Two impermeable layers 54a, 54b, are attached to
the bottom surface of the topsheet 24 forming two wetness sensation
members 50a, 50b. For this embodiment, the impermeable layers 54a,
54b are disposed between the topsheet and the absorbent core 28 so
that the topsheet forms the permeable layers 52 of the wetness
sensation members. The two impermeable layers 54a, 54b are disposed
parallel to and spaced apart from the longitudinal centerline 42 of
the diaper 20. The spacing is determined to allow enough liquid to
pass through to the core so as to prevent flooding that can result
in leakage of the absorbent article during urination, while at the
same time enable enough liquid to flow and wick towards the
impermeable layers forming the wetness sensation members. The
spacing between the impermeable layers can be about 10 mm but can
range from about 5 mm to about 15 mm and from about 8 mm and to
about 12 mm. For this embodiment, the impermeable layers 54a, 54b
are attached to the lower side of the topsheet 24 using adhesives,
ultrasonic bonds, radio frequency bonds, or other suitable means.
The attachment can comprise bonds covering the entire interface
between the impermeable layers and the topsheet, spot bonds or
bonds along the longitudinal and transverse edges of the
impermeable layers. Although the embodiment described in FIGS. 6a
and 6b show only two wetness sensation members, other absorbent
article embodiments having three or more wetness sensation members
are contemplated.
[0063] As shown in FIGS. 6a and 6b the spacing of the impermeable
layers provide room for an elongated slit opening 80 in the
topsheet 24. The elongated slit opening 80 is adapted to receive
feces from the wearer and isolate the same from the wearer's skin.
As shown, the slit opening 80 is preferably interposed between the
wetness sensation members 50a, 50b along the longitudinal
centerline 42 of the diaper 20. Elasticized regions 82 located
adjacent to the slit opening 80 maintain alignment of the slit
opening 80 with the wearer's anus during use. The elasticized
regions 82 may also deflect the wetness sensation members 50a, 50b
towards the wearer's skin to maintain contact therewith during use.
Exemplary elasticized topsheets including elongated slit openings
are disclosed in U.S. patent application Ser. No. 09/694,751.
Alternatively, the impermeable layers 54a, 54b of the wetness
sensation members 50a, 50b may be elastically foreshortened to
provide benefits of the elasticized regions 82 disposed in the
topsheet 24.
[0064] In another alternate embodiment shown in FIGS. 7a and 7b,
the topsheet 24 forms the permeable layer 52 similar to the
previous embodiment, however, the impermeable layers 54a, 54b are
disposed in two parallel Z-folds 90 formed in the topsheet 24 along
the longitudinal length of the diaper 20. The Z-folded topsheet may
be attached to the underlying layers along the longitudinal edges
of the topsheet 24 allowing the portion between the Z-folds of the
topsheet 24 to float freely. Elastic elements 92 are disposed along
the impermeable layers 54a, 54b in order to deflect the center
portion of the Z-folded topsheet outward away from the absorbent
core 28. The elastic elements 92 may be disposed along the outer
edges of the impermeable layers 54a, 54b as shown in FIG. 7b, or
alternatively, may be disposed in face-to-face relationship with
the impermeable layers 54a, 54b. The combination of the Z-folded
topsheet 24 and the elastic elements 92 maintains the wetness
sensation members in contact with the wearer's skin in the event
that the diaper sags or fits loosely around the wearer.
[0065] In order to prevent the portion of the topsheet between the
Z-folds from being forced into the gluteal groove and from
interfering with the barrier leg cuffs, the spacing between the
Z-folds can be about 65 mm and can range from about 50 mm to about
90 mm. Further, in order to control deflection of the portion of
the topsheet between the Z-folds, transverse bonds are produced
between the Z-folds in the first waist region, the second waist
region and the crotch region using adhesives, ultrasonic bonds,
radio frequency bonds, or other suitable means in order to control
deflection. These transverse bonds attach the Z-folded section to
the body-facing surface of the topsheet and the section between the
Z-folds to the underlying core.
[0066] In addition to incorporating the wetness sensation member
with the topsheet, the wetness sensation member of the present
invention may also be integrated with other components of the
diaper such as the barrier leg cuffs. The barrier leg cuffs may be
made from either permeable or impermeable material. In either case,
the barrier leg cuff material may form one of the layers of the
wetness sensation member.
[0067] An example of wetness sensation members integrated with the
barrier leg cuffs is shown in FIGS. 8a and 8b. The diaper 20 for
this embodiment includes barrier leg cuffs 100a, 100b made from
impermeable material. The barrier leg cuffs 100a, 100b extend along
the longitudinal edges of the diaper 20 in a parallel arrangement
disposed on the body-facing surface of the topsheet 24 leaving an
exposed center portion 184 of the topsheet 24 therebetween. For the
embodiment shown in FIGS. 8a and 8b, wetness sensation members
150a, 150b are incorporated with the barrier leg cuffs 100a, 100b
such that the barrier leg cuff material provides the impermeable
layer of the wetness sensation members. The permeable layer 110 can
extend the length of the barrier leg cuffs, preferably the length
of the crotch region 37 and the front waist region 36, and is
disposed on portions of the cuff closest to the longitudinal axis
42 of the diaper 20 to increase the likelihood of becoming wetted
during urination. As shown in FIGS. 8a and 8b, the barrier leg
cuffs 100a, 100b include Z-folded configurations with inner folds
105a, 105b disposed near the longitudinal axis 42 of the diaper 20
leaving a center portion 184 of the topsheet 24 exposed. The
Z-folded leg cuffs 100a, 100b also include outer folds 106a, 106b
having elastic elements 108 disposed therein. During use, the
elastic elements 108 deflect the leg cuffs away from the topsheet
24, towards the skin of the wearer.
[0068] The embodiments of wetness sensation members disclosed
hereunder perform effectively when held in contact with the skin of
the wearer. In order to ensure that contact is made with the
wearer's skin during use, the body-facing portion of the wetness
sensation members may include a topical adhesive or body adhering
composition, which acts to hold the wetness sensation member in
place during use. The topical adhesive may be applied to at least a
portion of the body-facing surface of the wetness sensation member.
However, the body adhering composition may also be integral with
the material making up the body-facing layer of the wetness
sensation member. Further, the body adhering composition may be
disposed on any portion of the wetness sensation member contacting
the skin of the wearer in any pattern or configuration including,
but not limited to lines, stripes, dots, and the like.
[0069] Types of body adhering composition may include any one or
more substances capable of releasably adhering to the skin of the
wearer. Further, the body adhering composition may be in the form
of a gel, lotion, film, web or the like. Examples of suitable body
adhering compositions include adhesives, gelatin, petrolatum, waxes
such as silicone or petroleum waxes, oils such as silicone or
petroleum based oils, skin care compositions or ingredients
thereof, as described below, and the like. Suitable topical
adhesives include, but are not limited to, hydrogel or hydrocolloid
adhesives such as acrylic based polymeric adhesives, and the like.
(Some exemplary hydrogel and/or hydrocolloid adhesives are
disclosed in U.S. Pat. Nos. 4,231,369; 4,593,053; 4,699,146;
4,738,257; and 5,726,250.) The topical adhesives may also include
any "medical adhesive" which is compatible for use with biological
tissue, such as skin. Acrylic medical adhesives suitable for use as
body adhering compositions include adhesives available from
Adhesive Research, Inc., of Glen Rock, Pa., under the designations
MA-46, MA-312, "MTTM" High MVTR adhesive, and AS-17. Rubber-based
medical adhesives, such as SB-2 from Adhesive Research Inc. may
also be suitable. Other exemplary adhesives include Dow Corning
Medical Adhesive (Type B) available from Dow Corning, Midland,
Mich.; "MEDICAL ADHESIVE" from Hollister Inc., of Libertyville,
Ill.; 3M Spray Adhesives #79, 76, 77 and 90 available from the 3M
Corp. of St. Paul, Minn.; and "MATISOL" liquid adhesive available
from Ferndale Laboratories of Ferndale, Mich. Other medical
adhesives are described in U.S. Pat. Nos. 4,078,568; 4,140,115;
4,192,785; 4,393,080; 4,505,976; 4,551,490; 4,768,503 and
polyacrylate and polymethacrylate hydrogel adhesives are disclosed
in U.S. Pat. Nos. 5,614,586 and 5,674,275. Yet another exemplary
adhesive comprising polyvinyl pyrrolidone and a multi-functional
amine-containing polymer is disclosed in WO 94/13235A1. Alternative
body adhering means, which may be used in place of or in addition
to those described above, include static electricity, suction, and
the like. In any case, it is preferred that the body adhering
composition permit vapors to pass (i.e., breathable), be compatible
with the skin and otherwise skin friendly. Further, it is preferred
that the body adhesive be at least partially hydrophobic,
preferably 60%, more preferably 80%, by weight of the adhesive
consist of hydrophobic components. However, hydrophilic adhesives
are contemplated in certain embodiments of the present
invention.
[0070] The disclosures of all patents, patent applications, and any
patents which issue thereon, as well as any corresponding published
foreign patent applications, and all publications listed and/or
referenced in this description, are hereby incorporated herein by
reference. It is expressly not admitted, however, that any of the
documents or any combination of the documents incorporated herein
by reference teaches or discloses the present invention.
[0071] While particular embodiments and/or individual features of
the present invention have been illustrated and described, it would
be obvious to those skilled in the art that various other changes
and modifications can be made without departing from the spirit and
scope of the invention. Further, it should be apparent that all
combinations of such embodiments and features are possible and can
result in preferred executions of the invention. Therefore, the
appended claims are intended to cover all such changes and
modifications that are within the scope of this invention.
* * * * *