Note: Descriptions are shown in the official language in which they were submitted.
CA 02830293 2013-10-15
BEDDING SYSTEM
FIELD OF THE INVENTION
The present invention relates generally to bedding systems, and more
particularly
to pads or sheets including a liquid-absorbing portion.
BACICROUND OF THE INVENTION
Waterproof bedding cover sheets or pads are useful to help families cope with
bedwetting for children and elderly people. Ideally, such a bedding sheet
would provide
the utmost in discretion and simplicity through combining superb protection
and modular
design to allow bed changes to happen in less than a minute, even with the
lights off.
Quick and effortless replacement, easy fit, and prevention of fluid passing
through to a
sheet or mattress are desired.
However, there are no reliable and durable off-the-shelf solutions available
to
securely attach/affix such a sheet to a bed sheet underneath quickly, for
example in 30
seconds in darkness. Also, the design and pattern of previously disclosed
protection
sheets do not match with the rest of the bed sets, whereas such matching is
very desirable.
Also, no available off-the-shelf products meet desirable design and leak-proof
goals such
as washability and water absorbency holding up to 360 cc of fluids.
A common method of attaching or affixing bedding sheets to a mattress is to
use
velcroTM or snapping methods. Such methods have several shortcomings such as:
choking
hazards; longevity; timely process for fitting, aligning, laying and securing
the sheet; and
durability.
SUMMARY OF THE INVENTION
The invention provides a liquid-absorbing pad comprising a top layer and a
bottom layer and an interior portion therebetween. The interior portion
includes a liquid-
absorbing material. The top layer is made from microfiber bed sheet material.
The bottom
layer is made from microfiber terry, the top of which is laminated with liquid-
impermeable material. The top layer and interior portion are quilted together
and glued to
the bottom layer. When the pad is laid on a bed sheet made of microfiber bed
sheet
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material extending horizontally, the pad resists horizontal movement relative
to the bed
sheet.
The interior portion preferably may further include a non-woven polypropylene
layer below the liquid-absorbing material so that the top layer, the liquid-
absorbing
material and polypropylene layer are quilted together. The polypropylene layer
may have
a density of greater than 80 GSM, and preferably about 100 GSM.
The microfiber terry used in the bottom layer may be non-oiled microfiber
terry.
The liquid-impermeable material may be made from polyurethane laminate
(PUL), or thermoplastic polyurethane (TPU). The liquid-impermeable laminate
may be
TPU with a thickness of about 0.02 mm.
The microfiber bed sheet material of the top layer may have a density of
between
80 and 120 grams per square meter (GSM), and preferably of about 100 GSM.
The liquid-absorbing material may consist of between 70% and 90% polyester,
polyamide, polypropylene, or polyester blended polyamide, and the remainder
may
comprise rayon filling. The liquid-absorbing material may consist of 80%
polyester,
polyamide, polypropylene, or polyester blended polyamide, and 20% rayon
filling. The
liquid-absorbing material consists of 80% polyester.
The liquid-absorbing material has a density of between 100 and 200 GSM, and
preferably about 160 GSM.
The liquid-absorbing material may consist of about 80% polyester, polyamide,
polypropylene, or polyester blended polyamide, and about 20% nylon filling,
The microfiber terry may consist of between 70% and 90% polyester and the
remainder may comprise nylon micro fiber yarn. The microfiber terry may
comprise 80%
polyester and 20% nylon micro fiber yarn with a density of between 100 and 240
GSM.
The microfiber terry may comprise between 70% and 90% polyester and the
remainder
may comprise nylon micro fiber yam with a density of between 180 and 220 GSM.
The
microfiber terry may comprise 80% polyester and 20% nylon micro fiber yarn
with a
density of 200 GSM.
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BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 shows a schematic top view of the bedding system in place on a bed.
Figure 2 shows the bedding system in place on a bed.
Figure 3 shows an exploded view of a liquid-absorbing pad.
Figure 4 shows the bedding system in a bag.
DETAILED DESCRIPTION OF THE INVENTION
The bedding system includes a top sheet, a bottom (fitted) sheet, a pillow
case,
and preferably at least two Sneaky Squares (liquid-absorbing pads, or
"sheets"). The key
element is the liquid-absorbing pad 100, which is placed on top of the bottom
sheet 101
on a bed, as can be seen in Figures 1 and 2. The user of the bed lies on top
of the liquid-
absorbing pad 100 and bottom sheet, the pad 100 being placed so that if the
user wets the
bed the liquid contacts the liquid-absorbing pad 100 rather than the bottom
sheet. The
liquid-absorbing pad 100 is configured to absorb the liquid, and also to
prevent or
minimize any transmission of the liquid through the liquid-absorbing pad 100
to the
bottom sheet. Thus, after an incident where liquid comes into contact with the
pad 100
(e.g. a bed-wetting incident), the liquid-absorbing pad 100 can be removed
and,
optionally, replaced by a second, clean, liquid-absorbing pad 100 very
quickly, without
having to remove and replace the bottom sheet.
The liquid-absorbing pad 100 is shown in an exploded view in Figure 3. The
liquid-absorbing pad 100 has a top layer 301 made of microfiber bed sheet
material,
preferably microfiber peach (also called microfiber peach skin and polyester
peach skin,
a velvet fabric that feels like peach skin). The microfiber bed sheet material
of the top
layer may have a density of 100 grams per square meter (GSM).
Below the top layer is a liquid-absorbing layer 302 made of a liquid-absorbing
material. The liquid-absorbing material preferably consists of 80% polyester
and 20%
rayon filling with a density in the range of about 120 and 240 GSM, and
preferably about
160 GSM. Laboratory testing was conducted on various padding materials with
various
densities and absorption ratings. Analyses of test results showed that
materials consisting
of 80% polyester and 20% rayon filling with a density of 160 GSM provide
excellent
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absorbency, so that such material is preferred. The volume of material is
selected so that
it can absorb up to about 360 ml (or cc) of liquid. Rather than using a 20%
rayon
formulation, 20% nylon may alternatively be employed, but this is not
preferred.
A third layer 303 may be employed which is composed of 100 GSM (or greater)
100% polypropylene non-woven material that can be bonded to the bottom layer
using
glue, since it is generally not feasible to bond the liquid-absorbing layer to
the bottom
layer using glue. The first three layers are quilted together. The use of such
a construction
results in a pad that can be washed more than 50 times.
The bottom layer comprises a liquid-impermeable coating 304 laminated on
microfiber terry 305, which is preferably non-oiled microfiber terry which
reduces odor
retention. The liquid-impermeable coating 304 is preferably made from PUL
(Polyurethane Laminate), or TPU (thermoplastic polyurethane), and is
preferably about
0.02 mm in thickness, although various thicknesses are possible.
When the pad 100 is laid on a bottom bed sheet (typically a fitted sheet) made
from microfiber bed sheet material extending horizontally, the pad 100 resists
horizontal
movement relative to the bed sheet. That is, in normal use, the pad 100 tends
to stay in
the same position despite the fact that the person in the bed may move during
use of the
bed. This resistance can be observed by attempting to pull the pad 100
horizontally by
gripping one or two points on one side of the pad 100. Moving the pad 100
horizontally
requires substantially more force than would be required with a prior art pad.
The bottom microfiber terry layer preferably is made of 80% polyester and 20%
nylon micro fiber yarn with a density of 200 GSM. The yarn may be 150DX288F.
Polyamide, polypropylene, and polyester blended polyamide are also preferred
materials.
In this system, the pad 100 is simply laid on top of the bottom sheet.
Normally
such an approach would not work effectively because the pad would move as the
user
moves in the bed, and would be likely to move sufficiently that the fitted
sheet would get
wet if the user wets the bed. The applicant has discovered a surprising
property of
microfiber terry relative to standard bed sheet material. When the pad 100 is
placed on
top of the sheet with the microfiber terry touching the micro fiber bed sheet
material, the
pad 100 resists horizontal movement relative to the bed sheet. The resistance
is
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sufficiently strong that, under normal use, the bed user will not cause the
pad 100 to
move significantly during a typical sleep period.
The pad 100 is preferably sized to cover all portions of the fitted sheet that
would
otherwise potentially become wet because of a bed wetting incident. As can be
seen in
Figure 2, the pad 100 preferably also covers a portion of the sides of the bed
to prevent
the associated portions of the fitted sheet from becoming wet. Generally, the
pad 100 is
sized so that it hangs about six inches over each side of the bed. This
overhang further
enhances the movement resistance property of the pad 100, which increases as
the
amount of microfiber terry touching the micro fiber bed sheet material
increases.
Microfiber is a fiber with less than 1 decitex per filament. Decitex is a
measure of
linear density and is commonly used to describe the size of a fiber or
filament. Ten
thousand meters of a 1-decitex fiber weighs one gram. While many microfibers
are made
of polyester, they can also be composed of polyamide or other polymers
polypropylene,
Polyester blended polyamide quality may be preferred since the hand feeling of
100%
polyester may not be of sufficiently high quality.
The bedding system may also include a bag, as shown in Figure 4, that can hold
the other components. The system can be sold with the components in the bag,
and the
user may subsequently use the bag to store the components. Preferably, the bag
is made
from 100 GSM printed micro fiber laminated with TPU. This makes the bag
particularly
suitable for storing a wet pad after it is removed from the bed. This further
facilitates
quickly replacing a soiled pad with a clean one as the user can leave the
soiled pad in the
bag until at least the next morning so that washing of the pad is deferred and
the time
spent by the user during the sleep period to deal with a bed wetting incident
is minimized.
Other approaches have been found to be inferior to the use of microfiber
Terry,
such as using velcroTM at the sides of the protection sheet. Since velcrolm
generally has
soft and rough pairs (hook and loop), it unclear how to determine an optimal
arrangement
to attach the velcroTM to the protection sheet and the bed sheet. In an
embodiment that is
not preferred, a rough (hook) piece of velcroTm was attached to the protection
sheet and a
soft (loop) part to the bed sheet. Samples were prepared and washed for 3
cycles. It was
determined that the hooks would collect peels and lint in the course of
washing, which
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reduced the effectiveness of the velcroTM in long term. Attaching the soft
part of velcroml
to the protection sheet was tried and showed improved results, however openly
exposed
hooks sewn to the bed sheet were considered to risk irritation of the user's
skin. The
possibility of introducing two flip over flaps to the sides of the bed sheet
to cover the
hooks was also considered. Evaluation of prototype samples determined the
flaps are in
the way and sometimes inaccessible when laying down the protection sheet,
especially
during the night when lights are off and one side of the bed is next to the
wall. Research
was conducted to identify alternative and applicable solutions such as using
grommets,
snaps, buttons, magnets, and zippers avoiding any health and safety hazard.
The use of
magnets was also assessed. However protection sheets with embedded magnets may
be
unacceptable when the product is used by people having embedded pacemakers.
Testing of sample protection sheets with standard microfiber Terry backing
have
shown that an undesired smell may result after about 10 washing cycles. This
was
determined to be because the oil content in the microfiber terry retains an
odor even after
washing. It was found that replacing the microfiber Terry with an oil-free
Terry fabric
resolved this issue.
While specific materials have been described, it would be apparent to skilled
persons that variants of the stated compositions would function substantially
the same
way, although the movement-resistance of the pad relative to the fitted sheet
may vary
somewhat.
The words "comprises" and "comprising", when used in this specification and
the
claims, are to used to specify the presence of stated features, elements,
integers, steps or
components, and do not preclude, nor imply the necessity for, the presence or
addition of
one or more other features, elements, integers, steps, components or groups
thereof.
The scope of the claims that follow is not limited by the embodiments set
forth in
the description. The claims should be given the broadest purposive
construction
consistent with the description as a whole.
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