U.S. patent application number 10/780545 was filed with the patent office on 2005-08-18 for flame barrier cushioning foams and upholstery layer construction incorporating such foams.
This patent application is currently assigned to Foamex L.P.. Invention is credited to Chan, Chiu Y., Deery, William H., Niederoest, Beat B., Tursi, Daniel V. JR..
Application Number | 20050177950 10/780545 |
Document ID | / |
Family ID | 34838624 |
Filed Date | 2005-08-18 |
United States Patent
Application |
20050177950 |
Kind Code |
A1 |
Niederoest, Beat B. ; et
al. |
August 18, 2005 |
Flame barrier cushioning foams and upholstery layer construction
incorporating such foams
Abstract
An upholstery construction for a mattress or an article of
furniture includes a flame barrier foam sheet proximate to the back
face of a surface fabric layer. The flame barrier foam sheet is
formed by coating or impregnating a polyurethane sheet with an
aqueous solution of one or more binder(s), such as but not limited
to a polyvinyl chloride copolymer or an acrylic latex binder, and
one or more flame retardant(s), such as but not limited to aluminum
trihydrate or melamine. The flame barrier foam sheet with dried
binder(s) and flame retardant(s) not only resists flame ignition
but also retains its cushioning properties.
Inventors: |
Niederoest, Beat B.;
(Medford Lakes, NJ) ; Deery, William H.;
(Wallingford, PA) ; Chan, Chiu Y.; (Wilmington,
DE) ; Tursi, Daniel V. JR.; (Media, PA) |
Correspondence
Address: |
CONNOLLY BOVE LODGE & HUTZ, LLP
P O BOX 2207
WILMINGTON
DE
19899
US
|
Assignee: |
Foamex L.P.
Linwood
PA
|
Family ID: |
34838624 |
Appl. No.: |
10/780545 |
Filed: |
February 17, 2004 |
Current U.S.
Class: |
5/698 ;
5/954 |
Current CPC
Class: |
C08J 9/365 20130101;
C08J 9/40 20130101; A47C 27/14 20130101; C08J 2475/00 20130101;
C08J 2431/00 20130101; C08J 2375/04 20130101; A47C 31/001 20130101;
C08J 2421/00 20130101; C08J 2427/00 20130101 |
Class at
Publication: |
005/698 ;
005/954 |
International
Class: |
A47C 027/00 |
Claims
We claim:
1. An upholstery construction for a mattress or an article of
furniture, comprising: a fabric layer having a front surface and a
back surface; a flame barrier foam sheet proximate to the back
surface of the fabric layer, wherein said flame barrier foam sheet
comprises a polyurethane foam sheet that is coated or impregnated
with a coating of one or more binders and one or more flame
retardants, and dried, further wherein said flame barrier foam
sheet after it has been coated or impregnated and dried has a
density of in the range of about 1.0 to 6.0 pcf and an compression
force deflection (CFD.sub.25) of in the range of about 0.1 to 0.4
psi.
2. The upholstery construction of claim 1, wherein the flame
barrier foam sheet is adjacent to the back surface of the fabric
layer.
3. The upholstery construction of claim 1, wherein the upholstery
construction is quilted such as by stitching together the flame
barrier foam sheet and fabric layer in combination with one or more
other layers.
4. The upholstery construction of claim 1, wherein the binder in
the coating has a glass transition temperature (Tg) of less than
about 10.degree. C.
5. The upholstery construction of claim 1, wherein the binder in
the coating has a glass transition temperature (Tg) of less than
about 0.degree. C.
6. The upholstery construction of claim 1, wherein the coated or
impregnated flame barrier foam sheet has a density of from about
2.0 to about 4.5 pcf.
7. The upholstery construction of claim 1, wherein the binder in
the coating is selected from the group consisting of: acrylic
latex, natural rubber latex, polyvinyl chloride copolymers,
ethylene vinyl chloride copolymers, vinyl acetate, vinylidene
chloride copolymers, vinyl acetate ethylene copolymers, neoprene,
acrylonitrile, polychloroprene, polyurethane, and mixtures
thereof.
8. The upholstery construction of claim 1, wherein the binder in
the coating has a chlorine content of at least about 20% on a dry
weight basis.
9. The upholstery construction of claim 1, wherein the flame
retardant in the coating is selected from the group consisting of:
melamine, a melamine derivative, aluminum trihydrate, polyvinyl
chloride, antimony oxide, expandable graphite, magnesium hydroxide,
urea, an amino phosphorous compound such as ammonium polyphosphate,
and mixtures thereof.
10. The upholstery construction of claim 9, wherein the coating
further comprises a liquid flame retardant.
11. The upholstery construction of claim 1, wherein the flame
barrier foam sheet prior to being coated or impregnated has a
density of less than about 1.5 pcf and an indentation force
deflection (IFD.sub.25) of about 15 lb-force or less.
12. The upholstery construction of claim 1, further comprising: a
second foam sheet installed proximate to the flame barrier foam
sheet.
13. The upholstery construction of claim 12, wherein the second
foam sheet is installed adjacent to the flame barrier foam sheet
and between the flame barrier foam sheet and a backing sheet.
14. The upholstery construction of claim 1, wherein the flame
barrier sheet resists yellowing when exposed to ultraviolet
light.
15. The upholstery construction of claim 1, wherein the flame
barrier sheet resists yellowing when exposed to one or more
NO.sub.x gases.
16. A mattress or article of upholstered furniture incorporating
the upholstery construction of claim 1.
17. A mattress or article of upholstered furniture incorporating
the upholstery construction of claim 13.
Description
[0001] This invention relates to flexible polyurethane foams
forming at least a portion of an upholstery layer in a bedding or a
furniture construction, wherein said foams have a lower density and
a desired indentation force deflection, and form a flame barrier to
shield more combustible materials in the bedding or furniture
construction from ignition by flame.
BACKGROUND OF THE INVENTION
[0002] Polyurethane foams with varying density and hardness may be
formed. Hardness is typically measured as IFD ("indentation force
deflection") or CFD ("compression force deflection"). Specifically,
IFD.sub.25 is the force required to compress the foam to 25% of its
original thickness or height. Tensile strength, tear strength,
compression set, air permeability, fatigue resistance, support
factor, and cell size distribution may also be varied, as can many
other foam properties. Specific foam characteristics depend upon
the selection of the starting materials, the foaming process and
conditions, and sometimes on the subsequent processing.
[0003] Cellular polyurethane structures typically are prepared by
generating a gas during polymerization of a liquid reaction mixture
comprised of a polyester or polyether polyol, an isocyanate, a
surfactant, catalyst and one or more blowing agents. The gas causes
foaming of the reaction mixture to form the cellular structure. The
surfactant stabilizes the structure.
[0004] Untreated cellular polyurethane structures tend to have
relatively high flammability, and open flame ignition continues to
be a concern where polyurethane foams are incorporated into bedding
and furniture. Many mattresses and upholstered furniture articles
must meet stringent flammability standards, such as the California
Technical Bulletin 603 developed by the California Bureau of Home
Furnishings for mattresses. Under the California TB603 standard, a
mattress must not reach a heat release rate in excess of 200 kW in
the first one-half hour after ignition using a specified energy
source. The mattress also cannot exceed a total heat release of 10
MJ in the first ten minutes. Experimentally, it has been found that
extremely flame resistant materials should be incorporated into the
outer layers of the mattress construction in order to satisfy the
California TB603 standard.
[0005] Some polyurethane foams are made more resistant to flame
ignition by incorporating flame retardants in situ into the
foam-forming composition. Often, when flame retardants are
incorporated in situ, particulate matter is incorporated into the
foam structure. Foams formed with flame retardants in situ tend to
have less desirable cushioning properties than foams without such
additives. It is also more difficult to load large amounts of flame
retardant into foams in situ to further increase flame retardance,
and larger flame retardant loadings further detract from foam
cushioning properties.
[0006] Higher levels of flame retardance can be achieved by
impregnating a polyurethane foam with a coating that incorporates
one or more flame retardants. Unfortunately, however, binder-coated
foams typically also have higher compression resistance (hardness),
and do not provide the same cushioning support that is achieved
with untreated foams. Thus, in situ flame retardant foam cushions
have been preferred, notwithstanding the fact that higher
flammability retardance is still desired.
[0007] Mattress constructions and furniture upholstery
constructions have obtained higher flame resistance by
incorporating a fabric or a fiber flame barrier between the
upholstery fabric and the cushioning materials (fiber fill or foam)
and support structure (springs or foam cushions) within the
constructions. The treated fabric or fiber flame barrier provides
the needed flame retardance, but has little or no cushioning
effect. Hence, either the comfort of the construction is reduced or
additional foam or other cushioning material is incorporated into
the construction in conjunction with the fabric or fiber flame
barrier to restore the original cushioning of the construction.
Better cushioning or lower cost mattress or furniture constructions
would be produced if such a fabric or fiber flame barrier could be
eliminated.
SUMMARY OF THE INVENTION
[0008] According to a first aspect of the invention, an upholstery
construction for a mattress or an article of furniture includes a
fabric layer having a front surface and a back surface and a flame
barrier foam sheet proximate to the back surface of the fabric
layer. The flame barrier foam sheet comprises a polyurethane foam
sheet that is coated or impregnated with a coating of one or more
binders and one or more flame retardants, and dried. After it has
been coated or impregnated and dried, the flame barrier foam sheet
has a density of in the range of about 1.0 to 6.0 pcf and an
compression force deflection (CFD.sub.25) of in the range of about
0.1 to 0.4 psi.
[0009] Preferably, the flame barrier foam sheet is adjacent to the
back surface of the fabric layer. Most preferably, when
incorporated into a mattress, the upholstery construction is
quilted such as by stitching together the flame barrier foam sheet
and fabric layer in combination with one or more other layers. The
one or more other layers may include a second foam sheet and a
nonwoven backing sheet. If included, the second foam sheet
preferably is installed adjacent to the flame barrier foam sheet,
such as between the flame barrier foam sheet and the backing
sheet.
[0010] The coating preferably is a liquid or an aqueous solution
that includes a liquid binder in combination with one or more fire
retardants, which may be solid or liquid or a combination thereof.
Preferably, the binder in the coating has a glass transition
temperature (Tg) of less than about 10.degree. C., most preferably
less than about 0.degree. C. The binder in the coating may be
selected from materials generally characterized as latexes, such as
those based on natural rubber, polyvinyl chloride, ethylene vinyl
chloride copolymer, vinyl acetate, vinylidene chloride copolymer
and vinyl acetate copolymer chemistry. Other binders may also be
used, such as those based on acrylonitrile, epoxy, polychloroprene
and polyurethane. Any mixture of the identified binders may also be
used. Most preferably, the binder in the coating has a chlorine
content of at least about 20% on a dry weight basis.
[0011] The solid flame retardant in the coating preferably is
selected from the group consisting of: melamine, a melamine
derivative, aluminum trihydrate, polyvinyl chloride, antimony
oxide, expandable graphite, magnesium hydroxide, urea, an amino
phosphorous compound such as ammonium polyphosphate, and mixtures
thereof. A liquid flame retardant may also be included in the
coating.
[0012] Preferably, the flame barrier foam sheet prior to being
coated or impregnated has a density of less than about 1.5 pcf and
an indentation force deflection (IFD.sub.25) of about 15 lb-force
or less. After coating, the coated or impregnated flame barrier
foam sheet preferably has a density of from about 2.0 to about 4.5
pcf.
[0013] According to a second aspect of the invention, a mattress or
an article of upholstered furniture incorporates the upholstery
construction. The upholstery construction preferably is quilted
when incorporated into a mattress. The flame barrier foam may be
first wrapped over a cushion and then installed proximate to the
fabric layer when incorporated into an article of furniture.
DESCRIPTION OF THE FIGURES
[0014] The invention will be more fully understood by referring to
the detailed specification and claims taken in connection with the
following drawings. For the purpose of illustrating the invention,
certain embodiments are shown in the drawings. It is understood,
however, that this invention is not limited to the precise
arrangements shown.
[0015] FIG. 1 is a schematic drawing of an apparatus to coat or
impregnate a foam sheet with an aqueous solution containing one or
more flame retardant compounds carried by a binder;
[0016] FIG. 2 is schematic cross-sectional view in side elevation
of an upholstery construction for a mattress or an article of
furniture according to the invention;
[0017] FIG. 3 is a schematic cross-sectional view in end elevation
of a mattress incorporating the upholstery construction of FIG. 2;
and
[0018] FIG. 4 is a schematic side elevational view of a test
configuration for testing the flame retardancy of a flame barrier
according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Referring first to FIG. 1, an impregnation method is shown.
A polyurethane foam sheet 10 is provided. Preferably, the
polyurethane foam sheet 10 has a thickness in the range of 0.25 to
0.5 inches. Other cushioning foams besides polyurethane foam, and
other foam thicknesses, may be used.
[0020] To achieve the desired cushioning properties in the flame
barrier foam sheet of the final upholstery construction, the
polyurethane foam forming the foam sheet 10 preferably has a
density of less than about 1.5 pounds per cubic foot (pcf), and an
IFD.sub.25 of about 15 or less, more preferably about 12 or less.
Of course, if different cushioning properties are desired, foam
sheets with different IFD.sub.25 values outside these preferred
values may be used.
[0021] IFD or "indentation force deflection" is determined in
accord with a procedure similar to ASTM D 3574. In this case, for
IFD.sub.25 a foam sample is compressed by 25% of its original
height and the force after one minute is reported. Foam samples
should be cut to a size 15".times.15".times.4" prior to
testing.
[0022] Referring again to FIG. 1, the polyurethane foam sheet 10 is
passed over a roller 12 and into a dip pan 14 that contains a
coating liquid 16. The foam sheet 10 picks up a quantity of the
coating 16 and is then passed between a set of nip rollers 18. The
amount of impregnation or coating pick up can be adjusted by
varying the gap between the nip rollers 18 and/or adjusting their
speed of rotation. A portion of the coating liquid 16 is squeezed
out of the foam sheet 10 by the nipping action of the nip rollers
18 and returns to the dip pan 14. From the nip rollers 18 the
impregnated foam sheet 10 is passed through one or a series of
drying ovens 20. The drying oven 20 may be a radiant heating oven,
a convective heating oven or a series of conductive heating
elements, or it may be any combination thereof. The coating is
dried or cured in the drying oven 20 before the impregnated foam
sheet that may form a flame barrier foam sheet 24 is wound over a
take up roller 22.
[0023] The coating liquid 16 may include an aqueous or solvent
based binder selected from the group generally characterized as
latexes, such as those based on acrylic, natural rubber, polyvinyl
chloride, ethylene vinyl chloride copolymers, vinyl acetate,
vinylidene chloride copolymers, and vinyl acetate ethylene
copolymers. Other binders suitable for use with polyurethane foam
may also be used, such as those based on acrylonitrile, epoxy,
polychloroprene and polyurethane. A combination of one or more such
binders may be included in the coating liquid. Preferably, the
binder forming the coating liquid has a glass transition
temperature (Tg) of less than 10.degree. C., most preferably, less
than 0.degree. C. Preferably, the binder has a chlorine content of
at least about 20% on a dry weight basis.
[0024] The binder may be filled with one or more liquid or solid
flame retardant materials to form the coating liquid. Preferably,
the solid flame retardants are selected from the group consisting
of polyvinyl chloride, melamine, melamine derivatives, aluminum
trihydrate, antimony oxide, expandable graphite, magnesium
hydroxide, urea, or an amino phosphorous compound, such as ammonium
polyphosphate. Preferably, the liquid flame retardants are selected
from the group consisting of brominated and chlorinated organic
compounds, such as commercially available tetrabromobenzoate esters
or chlorinated diphosphate esters. When incorporated, the liquid
fire retardant level typically is expected to be less than 25% of
the solid fire retardant level.
[0025] The solids level for the impregnating or coating
formulations that remain on the polyurethane foam sheet to form the
flame barrier foam sheet may be set forth as the percentage of the
coating that remains with the foam after drying or curing. The
solids level represents the percentage of the formulation that is
not volatile or aqueous. The solids level may be adjusted, for
example, to change the viscosity of the coating liquid or to
minimize the amount of drying time required. This solids level
adjustment is typically achieved by adjusting the amount of water
added to the coating formulation. Although the invention is not
limited to this range, a typical solids level for the coating or
impregnating formulations is between 40 and 60%.
[0026] The binder load factor may be set forth as the ratio of
total dry weight of the coating/impregnation material to the total
dry weight of the binder. The binder load factor affects the
adhesion of the coating to the polyurethane foam sheet. Although
the invention is not limited to this range, a typical load factor
for the coating or impregnating formulations is in the range of 3
to 12.
[0027] Referring next to FIG. 2, an upholstery construction 26 is
formed by layering the elements that form the construction. The
embodiment shown in FIG. 2 is a quilted upholstery construction 26
suitable for a mattress. A similar upholstery construction
(although usually not quilted) may be used in an article of
upholstered furniture. A fabric layer 28 forms the outer covering
of the mattress. One exemplary fabric layer 28 for a mattress is a
knit or woven stretch fabric comprising a blend of cotton and
polyester, such as 75% cotton and 25% polyester.
[0028] The flame barrier foam sheet 24 is positioned adjacent to
the fabric layer 28. Next, a second foam layer 29 is positioned
adjacent to the flame barrier foam sheet 24. Finally a nonwoven
backing 30 is positioned adjacent to the second foam layer 29. The
upholstery construction 26 is shown with both a flame barrier foam
sheet 24 and a second foam layer 29; however, it is also possible
to form the construction without such second foam layer 29. The
layers forming the bedding upholstery construction 26 preferably
are joined together, such as by sewing.
[0029] In a furniture upholstery construction, the flame barrier
foam sheet 24 would wrap a cushion core, and the flame barrier foam
sheet and cushion core would be encased in the upholstery fabric
layer 28. A second foam sheet 29 and a nonwoven backing 30 would
not normally be used. The upholstery fabric would be sewn together
to enclose the flame barrier foam sheet and cushion core to form an
upholstered furniture cushion.
[0030] Referring next to FIG. 3, a mattress 34 is formed with the
upholstery construction 26 of FIG. 2. Sections of the upholstery
construction 26 form the outer top and bottom surfaces of the
mattress 34. In addition, a flame barrier foam sheet 24 in
combination with an outer fabric 28 and a nonwoven backing 30 form
the outer side surfaces of the mattress 34. The innerspring unit 36
or other support structure is thus encased within the flame barrier
foam sheets forming the upholstery construction 26 at the top and
bottom, and the flame barrier foam sheet(s) along the sides of the
mattress. The flame barrier foam sheets thus shield the support
structure of the mattress from ignition sources that could cause
the support structure to ignite. In the Examples set out below, the
mattress support structure is a slab of polyurethane cushioning
foam. Other support structures, such as encased innersprings, or
innersprings in combination with cushioning foams or other
cushioning materials may be formed.
[0031] The flame barrier foam sheet according to the invention
resists yellowing from exposure to UV light or NOx gases. As
compared to equivalent foam compositions that were not coated or
impregnated with flame retardant filled binder, at least a fifty
percent (50%) reduction in yellowing as measured on the Delta b
scale was measured for samples that were exposed to 8 ppm NO.sub.2
gas, and also measured for samples exposed to accelerated
ultraviolet light in a QUV weathering unit. This is an advantage
particularly for flame barrier foam sheets used in upholstery
constructions for mattresses and furniture where the flame barrier
foam sheet is placed directly in contact with the surface fabric.
Color fastness of the flame barrier foam sheet will avoid or
minimize changes in the color(s) of the surface fabric visible to
consumers.
[0032] The invention is further illustrated, but not limited by,
the following examples.
EXAMPLES
[0033] Table 1 below sets out the composition of three exemplary
coating liquids that were used. Unless otherwise indicated, amounts
are reported as wet parts per hundred based on the weight of the
liquid.
1 TABLE 1 Coating 1 Coating 2 Coating 3 Water 40.102 37.216 39.919
AF-4500 -- 17.927 -- TR 520 9.705 -- -- RHOPLEX FR-1 -- -- 12.007
Aluminum trihydrate 46.117 44.734 47.994 AB100 3.008 -- -- Antimony
oxide 1.016 -- -- Kelzan 0.053 0.019 0.012 BYK-020 -- 0.109 0.067
Target total solids 54.9% 53.8% 54.0% Binder Load Factor 11.3 6.0
9.0
[0034] The Binder Load Factor is the ratio of total dry weight of
the coating to the total dry weight of the binder (e.g., TR 520 for
Coating 1, AF-4500 for Coating 2, and FR-1 for Coating 3). The
target total solids level is the percentage of the formulation that
is not volatile or aqueous, and thus the percentage of the coating
or impregnation material that remains with the foam after drying or
curing.
[0035] AF-4500 is an ethylene vinyl chloride binder supplied by Air
Products and Chemicals Corp. TR 520 is an acrylic latex binder
supplied by Rohm and Haas Co. RHOPLEX FR-1 is a polyvinylidene
chloride copolymer binder supplied by Rohm and Haas Co.
[0036] Aluminum trihydrate was a commercial grade. AB100 is a
chlorinated phosphate ester liquid flame retardant supplied by
Albemarle Corp.
[0037] Antimony oxide is a fire retardant synergist supplied by
Great Lakes Chemical Co.
[0038] BYK-020 is an anti-foaming agent supplied by BYK-Cheme.
[0039] Kelzan is a rheology modifier supplied by CP Kelco US,
Inc.
[0040] Coatings 1, 2 and 3 were impregnated onto sheets of
polyurethane foam using an impregnation process substantially as
set forth and describe above. In each case, the starting foam sheet
had a thickness of from 3/8 to 1/2 inch, a density of 1.1 pcf and
an IFD.sub.25 of about 9.0 lb-force.
[0041] Table 2 below sets out the thickness, density and
compression force deflection values for the coated foam samples
produced using the coating compositions of Coatings 1, 2 and 3. The
exemplary flame barrier foams were denominated A to F for ease of
reference. For comparison, Table 2 further sets out the thickness,
density and compression force deflection values for commercially
available flame barrier foams of Foamex International Inc. and
Chestnut Ridge Foam Inc.
[0042] 25% CFD was measured using the procedure set forth in ASTM D
3574. 25% CFD or CFD.sub.25 or "compression force deflection" is a
measure of the load-bearing properties of the foam and is
calculated by dividing the force required to depress a circular
platen into a 2".times.2" foam sample to deflect the foam to 25% of
its original foam height by the cross-sectional area of the sample.
Thus, the units for CFD are pounds per square inch or "psi".
2TABLE 2 Example Coating Density (pcf) CFD.sub.25 (psi) Thickness
(in) A 2 2.0 0.22 0.36 B 2 3.3 0.24 0.35 C 1 3.9 0.26 0.36 D 3 4.6
0.26 0.29 E 3 3.9 0.25 0.31 F 3 3.4 0.22 0.28 SAFLITE -- 9.8 1.95
0.37 SAFGUARD -- 7.2 0.83 0.38 FIRESEAL -- 5.7 0.59 0.30
[0043] FIRESEAL is coated flame retardant polyurethane foam
supplied by Foamex International Inc. SAFLITE and SAFGUARD are
other coated flame retardant foams supplied by Chestnut Ridge Foam
Inc. These coated foams are typically used to build mattresses for
the healthcare, correctional and university dormitory markets.
[0044] The commercially available foams FIRESEAL, SAFLITE and
SAFGUARD have higher densities and higher CFD.sub.25 than the flame
barrier foam sheets incorporated into the upholstery constructions
of the invention. Thus, the flame barrier sheets impregnated or
coated with binder add less weight and provide greater cushioning
support to a mattress construction.
[0045] Certain of the flame barrier foam sheets of the examples set
out in Table 2 were then used to form upholstery constructions. The
upholstery or quilting constructions included a top layer of
stretch bedding fabric (75% cotton and 25% polyester), a next layer
of the flame barrier foam sheet, a next layer of 1.0 inch thick
polyurethane cushioning foam that had a density of about 0.7 pcf
and an IFD25 of about 7 lb-force, and finally a nonwoven backing
layer. Simulated bedding mattresses were then constructed using the
upholstery constructions in order to evaluate the comfort and
cushioning characteristics as compared with other flame barrier
materials. The quilting constructions were placed on the top of a
supportive foam base. The supportive foam base was a polyurethane
foam slab cut to 8 inches thick. The supportive foam base had a
density of 2.0 pcf and an IFD.sub.25 of 51 lb-force.
[0046] These mattresses were compared for comfort with mattresses
formed with the same polyurethane foam slab, stretch bedding
fabric, cushioning polyurethane foam and nonwoven backing in
combination with competitive flame barrier fabrics instead of the
coated or impregnated polyurethane foam flame barrier sheet as used
in Examples A and C. The three flame barrier fabrics tested were
Chiquola S2574 and TexTech 8163B and 8204B. All of these flame
barrier fabrics are marketed as suitable for use in mattresses, and
are indicated as having ability to pass the California TB603
flammability test, as described above.
[0047] The upholstery or quilt constructions including the flame
barrier foam sheets of Examples A and C, and the quilt
constructions including S2574, 8163B and 8204B were placed over the
supporting foam base. A190 lb. adult reclined on the quilt
construction and foam base as part of a pressure map test using an
FSA unit purchased from Vista Medical. Five pressure measurements
were taken for each sample, and these measurements were then
averaged. Each test yielded an average pressure over the surface
area in contact with the quilt construction. The results are
reported in Table 3 below.
3 TABLE 3 Example A Example C S2574 8163B 8204B Av. Pressure 14.9
14.2 16.9 15.4 15.6 (mmHg)
[0048] Lower average pressures indicate greater comfort. Thus,
Example C had the lowest average pressure.
[0049] A full mattress prototype was built using the quilted
upholstery construction of Example C. The mattress had a quilt
construction with a cover fabric (of 75% cotton and 25% polyester),
the flame barrier of Example C, a one-inch thick sheet of QUILTFLEX
polyurethane foam (supplied by Foamex International Inc.), and a
nonwoven backing. The QUILTFLEX foam had a density of about 0.7 pcf
and an IFD.sub.25 of about 7 lb-force. The side border panels also
used the cover fabric, flame barrier and nonwoven backing, but
eliminated the sheet of QUILTFLEX foam.
[0050] The mattress so made was sent to the California Bureau of
Home Furnishings for testing under the TB603 flammability standard.
The mattress passed the flammability standard test as set forth
below, and was reported to have been more than 95% recovered.
4 Results Requirement Max. rate of heat release (kW) 15 Less than
200 kW in 30 min. Total heat release at end of 3 Less than 10 in
first ten test (MJ) min. Max. ceiling temperature 185 (.degree. F.)
Total smoke release at end of 16 test (m.sup.3) Total test duration
(min:sec) 10:01 30 min. max. observation Reason for termination
self- extinguished
[0051] A smaller scale flammability evaluation for the flame
barrier foam sheets was made using a simplified test set up.
Referring to FIG. 4, the test set up 40 requires that the flame
barrier foam sheet 24 be placed over a non-treated slab of
polyurethane foam 42. Optionally, a thermocouple 44 is installed
between the flame barrier foam sheet 24 and the slab 42. A fuel
source 46 is placed over the flame barrier foam sheet 24, such that
the fuel source 46 is separated from the slab 42 by the flame
barrier foam sheet 24. The preferred fuel source was a scrap of
carpet cushion foam of constant density that had been soaked in
isopropyl alcohol to a constant liquid pick up. The fuel source 46
was ignited and allowed to bum until extinguished. The flame spread
behavior and char formation were observed.
[0052] In the case of Examples A to F above, the fuel source 46
self extinguished before the underlying flame barrier foam sheet 24
or foam slab 42 ignited. This qualitative test thus establishes
that the flame barrier foam sheets 24 prevented ignition or
combustion of the underlying more combustible foam slab 42. The
flame barrier foam sheets 24 thus had good flame retardant
properties, and all of the other Examples A, B and D to F similarly
would be expected to be useful in helping to pass the California
TB603 flammability test.
[0053] While Examples A to F are all considered within the scope of
the invention, Examples D, E and F are particularly preferred. The
RHOPLEX FR-1 binder has a glass transition temperature (Tg) of
-17.degree. C. and a chlorine content of approx. 36% on a dry
weight basis. The combination of low glass transition temperature
and high chlorine content in the binder of the coating liquid
yielded flame barrier foam sheets with better flammability
performance and better cushioning performance than the flame
barrier foam sheets of Examples A, B and C.
[0054] The invention has been illustrated by detailed description
and examples of the preferred embodiments. Various changes in form
and detail will be within the skill of persons skilled in the art.
Therefore, the invention must be measured by the claims and not by
the description of the examples or the preferred embodiments.
* * * * *