U.S. patent application number 10/260151 was filed with the patent office on 2004-04-01 for bed pad.
This patent application is currently assigned to Kimberly-Clark Worldwide, Inc.. Invention is credited to Fell, David Arthur, LeMinh, Toan Thanh.
Application Number | 20040060112 10/260151 |
Document ID | / |
Family ID | 32029622 |
Filed Date | 2004-04-01 |
United States Patent
Application |
20040060112 |
Kind Code |
A1 |
Fell, David Arthur ; et
al. |
April 1, 2004 |
Bed pad
Abstract
Disclosed is a bed pad having improved leakage protection
provided by a folded absorbent structure. In one embodiment, the
bed pad uses a stabilized absorbent material folded into a central
channel, a pair of transversely disposed side margins, and a pair
of transversely disposed side margins.
Inventors: |
Fell, David Arthur; (Neenah,
WI) ; LeMinh, Toan Thanh; (Neenah, WI) |
Correspondence
Address: |
KIMBERLY-CLARK WORLDWIDE, INC.
401 NORTH LAKE STREET
NEENAH
WI
54956
|
Assignee: |
Kimberly-Clark Worldwide,
Inc.
|
Family ID: |
32029622 |
Appl. No.: |
10/260151 |
Filed: |
September 27, 2002 |
Current U.S.
Class: |
5/484 |
Current CPC
Class: |
A61F 2013/15056
20130101; A47C 27/005 20130101 |
Class at
Publication: |
005/484 |
International
Class: |
A47G 009/00 |
Claims
We claim:
1. A bed pad comprising: an absorbent structure disposed adjacent a
bottomsheet, the absorbent structure having a stabilized absorbent
material, and the absorbent structure is folded at least twice; and
the bed pad having a width W.sub.P, the absorbent structure having
a width W.sub.A, and a ratio of W.sub.A/W.sub.P is from about 0.2
to about 0.8.
2. The bed pad of claim 1 wherein the folded absorbent structure
comprises a central channel and a pair of transversely disposed
side dams adjacent the central channel.
3. The bed pad of claim 2 wherein the folded absorbent structure
comprises a pair of oppositely disposed side margins adjacent the
side dams.
4. The bed pad of claim 2 wherein the central channel has a width
W.sub.C and the width W.sub.C is greater than about 200 mm.
5. The bed pad of claim 4 wherein the width W.sub.C is greater than
about 400 mm.
6. The bed pad of claim 1 wherein the ratio W.sub.A/W.sub.P is from
about 0.3 to about 0.6.
7. The bed pad of claim 1 wherein the bottomsheet and the absorbent
structure are plied together prior to folding, and the folded
portion is joined together by at least one adhesive bead.
8. The bed pad of claim 7 wherein the bed pad comprises a central
channel and the width of the central channel is adjustable.
9. The bed pad of claim 1 further comprising a barrier layer
disposed between the bottomsheet and the absorbent structure, and a
topsheet disposed adjacent the absorbent structure.
10. A bed pad having a central longitudinal axis and a central
transverse axis comprising: a center portion and a pair of
transversely disposed side portions, the center portion having an
absorbent structure disposed between a topsheet and a bottomsheet,
and the side portions free of the absorbent structure; the
absorbent structure folded from an absorbent material into a
central channel, and a pair of transversely disposed side dams
adjacent the central channel, and the central channel having a
width W.sub.C greater than about 200 mm.
11. The bed pad of claim 10 wherein the width W.sub.C is greater
than the width of a person's posterior when lying longitudinally on
the bed pad.
12. The bed pad of claim 10 wherein the absorbent structure
comprises a stabilized absorbent material.
13. The bed pad of claim 10 wherein the topsheet, the absorbent
structure, and the bottomsheet are plied together prior to folding
and the folded portion is joined together by at least one adhesive
bead.
14. The bed pad of claim 13 wherein the width W.sub.C is adjustable
by pulling transversely on the side portions.
15. The bed pad of claim 10 wherein the absorbent structure further
comprises a pair of oppositely disposed side margins adjacent the
side dams.
16. The bed pad of claim 10 wherein the bed pad has a width W.sub.P
and the absorbent structure has a width W.sub.A and a ratio of
W.sub.A/W.sub.P is from about 0.2 to about 0.8.
17. The bed pad of claim 10 wherein a barrier layer is disposed
between the absorbent structure and the bottomsheet.
18. A bed pad having a central longitudinal axis and a central
transverse axis comprising: a center portion and a pair of
transversely disposed side portions, the center portion having an
absorbent structure disposed between a topsheet and a bottomsheet,
and the side portions free of the absorbent structure; the
absorbent structure folded from a stabilized absorbent material
into a central channel, and a pair of transversely disposed side
dams adjacent the central channel, and the central channel having a
width W.sub.C greater than about 200 mm.
19. The bed pad of claim 18 wherein the stabilized absorbent
material has a basis weight from about 100 gsm to about 1000
gsm.
20. The bed pad of claim 18 wherein the stabilized absorbent
material has a density from about 0.1 g/cc to about 0.4 g/cc under
a load of 0.35 kPa.
21. The bed pad of claim 18 wherein the stabilized absorbent has an
absorbent capacity greater than about 8 g/g.
22. The bed pad of claim 18 wherein the side dams remain
uncompressed when a person lays on the bed pad.
Description
BACKGROUND
[0001] Bed pads are used by hospitals, long term care facilities,
and private homes to protect bedding, mattresses, cushions, seats,
and so forth from being soiled by individuals. Often these bed pads
are prone to leakage resulting in damage to the article the bed pad
was supposed to protect. The leakage often results from lateral
leakage of bodily wastes before being fully absorbed by the
absorbent structure of the bed pad. Hence, there is a need to
improve the absorbent structures of bed pads in order to enhance
their functionality.
SUMMARY
[0002] The present invention provides a solution to improving the
absorbent structure of a bed pad to prevent leakage by folding the
absorbent structure at least twice to form a central channel and a
pair of oppositely disposed side dams. By creating a central
channel and side dams, lateral leakage of bodily wastes is reduced
and performance of the bed pad is increased.
[0003] Hence in one aspect, the invention resides in a bed pad
including an absorbent structure disposed adjacent a bottomsheet,
the absorbent structure having a stabilized absorbent material, and
the absorbent structure is folded at least twice. The bed pad
having a width W.sub.P, the absorbent structure having a width
W.sub.A, and the ratio of W.sub.A/W.sub.P is from about 0.2 to
about 0.8.
[0004] In another aspect, the invention resides in a bed pad with a
central longitudinal axis and a central transverse axis, and the
bed pad having a center portion and a pair of transversely disposed
side portions. The center portion having an absorbent structure
disposed between a topsheet and a bottomsheet, and the side
portions free of the absorbent structure. The absorbent structure
being folded from an absorbent material into a central channel and
a pair of transversely disposed side dams adjacent the central
channel, and the central channel having a width W.sub.C greater
than about 200 mm.
[0005] In yet another aspect, the invention resides in a bed pad
with a central longitudinal axis and a central transverse axis. The
bed pad including a center portion and a pair of transversely
disposed side portions. The center portion having an absorbent
structure disposed between a topsheet and a bottomsheet, and the
side portions free of the absorbent structure. The absorbent
structure folded from a stabilized absorbent material into a
central channel, and a pair of transversely disposed side dams
adjacent the central channel, and the central channel having a
width WC greater than about 200 mm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The above aspects and other features, aspects, and
advantages of the present invention will become better understood
with regard to the following description, appended claims, and
accompanying drawings:
[0007] FIG. 1 illustrates a plan view of one embodiment of the
invention.
[0008] FIG. 2 illustrates a cross-section view of the embodiment of
FIG. 1.
[0009] FIG. 3 illustrates a cross-section view of an alternative
embodiment of the invention.
DEFINITIONS
[0010] As used herein, "absorbent capacity g/g" is the grams of
saline retained by the absorbent material per gram of the absorbent
material. Absorbent capacity is determined by conditioning the test
samples in a standard laboratory atmosphere of 23.+-.1.degree. C.
and 50.+-.2% RH for at least 24 hours prior to testing the sample.
All testing is conducted under the standard laboratory conditions.
Weigh a piece of absorbent material to the nearest 0.001 gram and
place in a bath of 0.9 percent by weight sodium chloride solution
at 20.degree. C. Allow the sample to soak for 20 minutes ensuring
an excess amount of saline is present in the bath to completely
saturate the sample. After 20 minutes, remove the sample and place
on a vacuum box having a suitable mesh screen for holding the
sample while removing excess saline from the sample. Cover the
vacuum box and sample with a flexible latex sheet. Apply a 3.45 kPa
vacuum to the vacuum box and sample for a period of 5 minutes to
remove excess non-absorbed saline from the sample. After 5 minutes,
remove the sample and weigh to the nearest 0.001 gram. Calculate
the absorbent capacity g/g by subtracting the dry sample weight
from the saturated sample weight and dividing the result by the dry
sample weight.
[0011] As used herein, "side dams" refers to an area where the
absorbent structure is folded one or more times such that the
absorbent structure has an increased thickness and basis weight in
the folded area relative to the absorbent structure adjacent to the
folded portion.
[0012] As used herein, "side margins" refers to an area of the
absorbent structure transversely disposed outward of the side dams
where the absorbent structure returns to its original thickness and
basis weight.
[0013] As used herein "stabilized absorbent material" means an
absorbent material containing a binder that causes bonds to form
between fibers such that the absorbent material has a tensile
strength of at least 5 Newtons per 50 mm (N/50 mm) in either the
machine or cross machine direction. The tensile strength of the
material can be tested using a tensile tester such as MTS/Sintech
model 1/S which is commercially sold by MTS Systems Corporation
having a mailing address of P.O. Box 14226, Research Triangle Park,
N.C. The tensile strength at peak load for the purpose of this
invention is measured by securing a 50 mm wide strip of stabilized
absorbent material between two movable jaws of a tensile tester. A
distance of about 10 cm initially separates the two jaws. The two
jaws are then moved outward away from one another at a rate of 25
cm/minute until the strip of material breaks. The tensile strength
is recorded as the peak load.
DETAILED DESCRIPTION
[0014] Referring now to FIG. 1 a bed pad 20 is illustrated in plan
view. The bed pad 20 has a center portion 22 and two oppositely
disposed side portions 24. The side portions 24 are substantially
free of an added absorbent material, which is located in the center
portion 22 (see FIG. 2); although, the material forming the side
portions may be absorbent to some degree depending on the specific
material utilized.
[0015] The bed pad has a longitudinal central axis 26 and a
transverse central axis 28. The bed pad can be any suitable length
and width required. Generally, the bed pad will have a width from
about 750 mm to about 3000 mm. The length of the bed pad can be
from about 500 mm to about 2500 mm. In one embodiment, the bed pad
has a longitudinal length of about 1000 mm and a transverse width
of about 2000 mm.
[0016] Referring now to FIG. 2, the bed pad 20 of FIG. 1 is shown
in a cross-sectional view. The bed pad 20 has a bottomsheet 30 and
an absorbent structure 32. Optionally, the bed pad 20 can include a
barrier layer 34 disposed between the absorbent structure 32 and
the bottomsheet 30. A topsheet 36 is optionally disposed over at
least a portion of the absorbent structure 32.
[0017] The absorbent structure 32 of the bed pad is folded one or
more times to form a central channel 38, a pair of transversely
disposed side dams 40, and a pair of oppositely disposed side
margins 42 adjacent the side dams. Although the embodiment of FIG.
2 shows the absorbent structure 32 "Z" folded on either side of the
central channel 38, it is possible to "C" fold the absorbent
structure and eliminate the side margins 42. It is also possible to
eliminate the side margins 42 and fold the absorbent structure 32
two, three, four or more times on either side of the central
channel 38 to form the side dams 40. Desirably, the side margins 42
are present to collect and absorb any bodily wastes that may not be
fully contained by the side dams 40 and the central channel 38.
[0018] While FIG. 2 illustrates the central channel 38 positioned
adjacent to and underneath the topsheet 36, it is also possible to
construct the bed pad with the absorbent structure 32 inverted. In
such a configuration, the central channel 38 would be adjacent to
the barrier layer 34, with a layer of the absorbent structure above
the central channel positioned adjacent to the topsheet 36. Such a
configuration also provides improved transverse leakage protection
from the increased basis weight of the side dams.
[0019] The central channel 38 has a transverse width W.sub.C. The
width of the central channel W.sub.C is large enough to collect and
contain bodily wastes between the side dams 40 when a person is
lying on the bed pad 20. In one embodiment, the width W.sub.C was
greater than that of a person's posterior or buttocks when
centrally positioned on top of the bed pad and lying parallel to
the longitudinal axis 26. Such a width is preferred since the side
dams will have their greatest utility if they remain outside the
portion of the pad being laid on by the user and therefore
uncompressed by that person's weight. When the side dams are
uncompressed, they have a greater ability to retain and absorb
bodily wastes enhancing leakage protection. Since the width of an
individual's body can vary considerably, it is envisioned two or
more sizes of the bed pad having a different W.sub.C dimension can
be made to accommodate different sized individuals ranging from
infants to large adults. Specifically, the width W.sub.C can be
greater than about 200 mm. More specifically, the width W.sub.C can
be greater than about 400 mm. More specifically still, the width
W.sub.C can be greater than about 600 mm.
[0020] The absorbent structure 32 can be formed from any suitable
absorbent material such as natural or synthetic fibers, cellulose,
foams, and superabsorbent particles. In one embodiment, the
absorbent structure 32 is a stabilized absorbent material. A
stabilized absorbent material is desirable due to its superior
performance in resisting bunching and tearing when wet as a person
using the bed pad moves and shifts position. In addition, the
stabilized absorbent material is readily folded and processed by
converting equipment to create the side dams 40 and central channel
38 as opposed to a conventional fluff pulp/suberabsorbent material,
which has a much lower tensile strength. The absorbent structure
can have a density ranging from about 0.1 grams per cubic
centimeter (g/cc) to about 0.4 g/cc under a load of 0.35 kPa. The
absorbent capacity of the absorbent structure can be greater than
about 8 g/g. The basis weight of the absorbent structure can range
from about 100 grams per square meter (gsm) to about 1000 gsm.
[0021] The stabilized absorbent material can be an airlaid or a wet
laid material. Desirably, the stabilized material is an airlaid
material, constructed of a blend of cellulose fibers, a binder,
preferably in the form of a second group of fibers, and a
superabsorbent.
[0022] The blended mixture is cured to form a stabilized, airlaid
absorbent material. One suitable stabilized absorbent material is a
175 gsm SMARTCORE material, product number 175.1341, commercially
available from Concert Fabrication LTEE having an office at 1680
Atmec Street, Gatineau, Quebec, Canada JAP7G7.
[0023] The cellulose fibers of the stabilized absorbent can include
about 25 percent to about 96 percent of the stabilized absorbent
material by weight. One suitable cellulose pulp is identified as
NB-416 southern softwood sold by Weyerhauser Corporation having an
office in Tacoma, Wash., USA.
[0024] The binder of the stabilized absorbent can comprise from
about 4 percent to about 15 percent by weight of the stabilized
absorbent material. The binder can be a chemical agent such as the
wet strength additive KYMENE available from Hercules, Inc. having
an office at 7510 Bay Meadows Way, Jacksonville, Fla. 32256, USA.
Desirably, the binder will consist of a second group of fibers. The
second group of fibers can be synthetic binder fibers. Synthetic
binder fibers are commercially available from several suppliers.
One such supplier is Trevira GmbH & Company KG having a mailing
address of Max-Fischer-Strasse 11, 86397 Bobingen, Deutschland.
Another supplier of binder fibers is Fibervisions A/S having a
mailing address of Engdraget 22, Dk-6800 Varde, Denmark. A third
supplier of binder fibers is KoSa having a mailing address of P.O.
Box 4, Highway 70 West, Salisbury, N.C. 28145. Desirably, the
binder fibers are bicomponent fibers having a polyester core
surrounded by a polyethylene sheath. Alternatively, the binder
fibers can be bicomponent fibers having a polypropylene core
surrounded by a polyethylene sheath. One suitable binder fiber for
use in the stabilized absorbent is a KoSa T255, 2 denier, 6 mm,
polyethylene sheath polypropylene core fiber.
[0025] The optional superabsorbent of the stabilized absorbent can
include from about 0 percent to about 60 percent by weight of the
stabilized absorbent material. The superabsorbent can be a
polyacrylic acid and is desirably in the shape of small particles,
although fibers, flakes or other forms of superabsorbents can also
be used. One suitable superabsorbent is Stockhausen Superabsorber
FAVOR 880. FAVOR 880 is commercially available from Stockhausen,
Inc. having an office located at 2408 Doyle Street Greensboro, N.C.
27406. Other superabsorbents, some of which are commercially
available from Dow Corporation having an office in Midland, Mich.,
USA, can also be used.
[0026] Referring back to FIG. 2, the absorbent structure, after
folding, has a width W.sub.A which also defines the width of the
center portion 22. As mentioned, the side portions 24 are
substantially free of an added absorbent material, such as
absorbent structure 32, although the material forming the side
portions may be absorbent to some degree depending on the specific
material utilized. The side portions 24 can include a topsheet
layer 36 or a barrier layer 34 if desired. The bed pad has an
overall width W.sub.P as illustrated.
[0027] To maximize the leakage performance of the bed pad, it has
been determined that the ratio of W.sub.A/W.sub.P can be maintained
within specific ranges. By centralizing the absorbent structure 32,
bodily wastes will be contained in the center of the bed pad 20,
and the side portions 24 can be used to hold the bed pad to the
mattress by tucking the side portions 24 underneath the mattress
similar to a sheet. In one embodiment, the bed pad 20 has an
absorbent structure width W.sub.A equal to 810 mm, an overall width
W.sub.P equal to 2000 mm, and a ratio W.sub.A/W.sub.P equal to 0.4.
Specifically, the ratio W.sub.A/W.sub.P ranges from about 0.2 to
about 0.8. More specifically, the ratio W.sub.A/W.sub.P ranges from
about 0.3 to about 0.6. More specifically still, the ratio
W.sub.A/W.sub.P ranges from about 0.4 to about 0.5.
[0028] The bottomsheet 30 can be liquid impermeable or liquid
permeable, and constructed from a woven, a nonwoven, a film, or a
plastic material. Desirably, the bottomsheet is liquid impermeable
or treated to be liquid impermeable with a coating such as a
polyethylene. In one embodiment, the liquid impermeable bottom
sheet is a 32 gsm material formed form a 22 gsm
spunbond/meltblown/spunbond nonwoven treated with a 10 gsm clear
polyethylene coating.
[0029] To further enhance the liquid impermeability of the bed pad,
a barrier layer 34 can be optionally located between the absorbent
structure 32 and the bottomsheet 30. The barrier layer is a liquid
impermeable material and can cover the entire width and length of
the bed pad if desired. Generally, the barrier layer 34 will be
disposed only in the area underneath the absorbent structure 32 or
in a slightly larger area than the absorbent structure to minimize
costs. In one embodiment, the barrier layer is a 25 .mu.m blue
polyethylene film, product number 152S available from Australian
Challenge, Artlou Division having an office at 103 Bernard Street,
Cheltenham, Victoria 3192, Australia.
[0030] To provide a soft, comfortable, non-irritating surface for
the patient, a topsheet 36 can be disposed over the absorbent
structure 32. The topsheet is desirably less hydrophilic then the
absorbent structure, and is liquid permeable to permit liquids to
readily pass through to the absorbent structure. Suitable topsheets
can be manufactured from a wide selection of materials such as
woven fabrics, nonwovens, and apertured films. In one embodiment,
the topsheet is a 17 gsm nonwoven polypropylene spunbond available
from Kimberly-Clark Corporation having an office in Roswell, Ga.,
USA. The topsheet can be treated to render it more hydrophilic, if
desired, as known to those of skill in the art.
[0031] The various layers of the bed pad can be joined together
using suitable adhesives applied by spraying, slot coating, or
other means as known to those of skill in the art. Alternatively,
ultrasonic bonding, heat welds, stitching, or other means known to
those of skill in the art can be used to join the layers together.
In one embodiment, hot melt adhesive having a product code 234-5610
supplied by National Starch having an office in Bridgewater, N.J.,
USA is used. Depending on the specific material used for the
absorbent structure 32, one or more adhesive beads 44 can be
applied to one or more of the folds within in the side dams 40 to
secure the absorbent structure. For instance, absorbent structures
that are highly resilient may require the addition of the adhesive
bead 44 to tack the side dams into position.
[0032] Referring now to FIG. 3, an alternative embodiment for the
bed pad is illustrated. In this embodiment, the topsheet 36, the
absorbent structure 32, and the bottomsheet 30 are plied together
and joined to each other by suitable adhesives. Then the entire
laminate is "Z" folded twice to form the central channel 38 and the
side dams 40. Alternatively, only the bottomsheet 30 and absorbent
structure 32 can be joined together and folded with the topsheet 36
disposed over the assembly after the central channel 38 and side
dams 40 have been formed. The adhesive beads 44 are applied to the
bottomsheet 30 prior to folding to tack an upper portion 48 of the
folded assembly together. A lower portion 50 of the folded assembly
adjacent the central channel 38 is not joined by the adhesive bead
44 as illustrated. In use, the width of the central channel W.sub.C
can be adjusted by moving the side portions 24 in the direction
indicated by arrow 46. As the side portions are moved transversely
outward, the width of the central channel W.sub.C is increased
since the lower portions 50 of the folded assembly are not glued
into position. Thus, the side dams 40 can rotate and stand more
upright as the side portions 24 are moved outward. As a result, the
height of the side dams 40 is increased as the width of the central
channel W.sub.C is increased. The side portions 24 can be moved to
their desired location and then tucked or held in position. The
incontinent patient is then placed onto the bedpad 20 lying in the
central channel 38 with the side dams 40 located along either side
of the patient. It will be appreciated that the foregoing
description, given for the purposes of illustration, is not to be
construed as limiting the scope of the invention, which is defined
by the claims and all equivalents thereto.
* * * * *