U.S. patent application number 11/266547 was filed with the patent office on 2007-05-03 for pillow-top mattress comprising a fire blocked gusset.
Invention is credited to Warren F. Knoff.
Application Number | 20070094802 11/266547 |
Document ID | / |
Family ID | 37994391 |
Filed Date | 2007-05-03 |
United States Patent
Application |
20070094802 |
Kind Code |
A1 |
Knoff; Warren F. |
May 3, 2007 |
Pillow-top mattress comprising a fire blocked gusset
Abstract
This invention relates to an improved gusset for use in
fire-blocking a pillow-top mattress. This gusset provides
additional fire blocking to provide a pillow-top mattress with
improved performance when tested according to Technical Bulletin
603 of the State of California.
Inventors: |
Knoff; Warren F.; (Richmond,
VA) |
Correspondence
Address: |
E I DU PONT DE NEMOURS AND COMPANY;LEGAL PATENT RECORDS CENTER
BARLEY MILL PLAZA 25/1128
4417 LANCASTER PIKE
WILMINGTON
DE
19805
US
|
Family ID: |
37994391 |
Appl. No.: |
11/266547 |
Filed: |
November 3, 2005 |
Current U.S.
Class: |
5/691 |
Current CPC
Class: |
A47C 31/001
20130101 |
Class at
Publication: |
005/691 |
International
Class: |
A47C 31/00 20060101
A47C031/00 |
Claims
1. A fire blocked pillow-top mattress, comprising: a) a mattress
body having a border comprising a first fire blocker, b) a pillow
for said mattress, and c) a gusset covering the joint between the
mattress body and the pillow, wherein the gusset includes a second
fire blocker that has a higher basis weight than the first fire
blocker.
2. The fire blocked mattress of claim 1 wherein the second fire
blocker has at least 20% higher basis weight than the first fire
blocker.
3. The fire blocked mattress of claim 1 wherein the second fire
blocker has at least 50% higher basis weight than the first fire
blocker.
4. The fire blocked mattress of claim 1 wherein the pillow is also
fire blocked.
5. The fire blocked mattress of claim 4 wherein the pillow is fire
blocked with the first fire blocker.
6. The fire blocked mattress of claim 1 wherein the gusset is
attached to the mattress body and pillow by sewing.
7. The fire blocked mattress of claim 1 wherein the first or second
fire blocker is a nonwoven fabric.
8. A fire blocked pillow-top mattress, comprising: a) a mattress
body having a seam connecting a panel of the mattress body and a
side border, the side border having fire blocking, b) a pillow
having a seamed outer edge, the pillow having a contact point with
the mattress panel inboard from the side border of the mattress,
the seamed outer edge of the pillow also extending outboard above
such contact point, wherein the area extending from the seam of the
mattress body across the mattress panel to the pillow contact point
and up the underside of the pillow surface to the seamed outer edge
of the pillow has more fire blocking than that found in the
mattress side border.
9. The fire blocked mattress of claim 8 wherein the pillow is also
fire blocked.
10. The fire blocked mattress of claim 8 wherein the gusset is
attached to the mattress body and pillow by sewing
11. The fire blocked mattress of claim 8 wherein the fire blocking
comprises a nonwoven fabric.
12. A process for fire blocking a pillow-top mattress comprising a
mattress body having a side border and a pillow having a top panel,
with a gusset covering the joint between the mattress body and the
pillow, comprising the steps of: a) incorporating a first fire
blocker into the mattress side border, and b) incorporating a
second fire blocker into gusset, wherein the second fire blocker
has a higher basis weight than the first fire blocker.
13. The process of claim 12 wherein the top panel of the pillow is
also fire blocked with either the first or second fire blocker.
14. The process of claim 12 wherein the first or second fire
blocker is a nonwoven fabric.
15. A process for fire blocking a pillow-top mattress comprising a
mattress body having a side border and a pillow having a top panel,
with a gusset covering the joint between the mattress body and the
pillow, comprising the steps of: a) incorporating a single layer of
a fire blocker fabric into the mattress side border and b)
incorporating a plurality of layers of a fire blocker fabric into
the gusset.
16. The process of claim 15, wherein each layer of the fire blocker
fabric used in the border and the gusset are the same fabric.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to an improved gusset for use in
fire-blocking a pillow-top mattress. This gusset provides
additional fire blocking to provide a pillow-top mattress with
improved performance when tested according to Technical Bulletin
603 of the State of California.
[0003] 2. Description of Prior Art
[0004] The State of California has led the drive to regulate and
reduce the flammability of mattresses and mattress sets in an
attempt to reduce the number of lives lost in household, hotel, and
institutional fires. In particular, the Bureau of Home Furnishings
and Thermal Insulation of the Department of Consumer Affairs of the
State of California issued Technical Bulletin 603 "Requirements and
Test Procedure for Resistance of a Residential Mattress/Box Spring
Set to a Large Open-Flame" to quantify the flammability performance
of mattress sets.
[0005] Mattresses are sold by a consumer's initial impression of
support and comfort and therefore mattresses normally contain, in
addition to any supporting foam or steel springs in the mattress
body, surface cushioning material made from light density fibrous
battings or foams, or a combination of both, that provide a surface
cushioning effect, but can be very flammable.
[0006] The mattress design referred to in the industry as a
pillow-top mattress has an additional cushion or pillow attached to
the mattress core to provide even more cushioning material. In
addition, to emphasize the pillow look of the mattress, the pillow
is attached to the mattress body inboard of the edge or side border
of the mattress body, giving the mattress a true "pillow-top" look.
By attaching the cushion or pillow in this manner, the side of the
mattress has an area of indention, where the bottom face of the
pillow or cushion projects over the mattress body. The joint
between the mattress body and the pillow is typically covered with
a fabric gusset. The fabric gusset normally extends from the out
board upper seam of the mattress body, across the upper surface of
the mattress body to the point where the pillow contacts the
mattress body, and then up the underside of the pillow surface to
the outboard edge of the pillow.
[0007] This additional surface area of the gusset creates a major
problem in passing the California test of the fire blocking
performance of the mattress that has not been addressed previously.
During the test, the flame jet from the side burner impacts the
vertical surface of the side border of the mattress and the rising
heat and flames tend to concentrate in the indentation between the
pillow and the mattress body, causing the underside of the pillow
to experience more intense heat and flame than the vertical side of
the mattress border, resulting in the failure of the otherwise
adequately fire blocked mattress.
[0008] What is needed, therefore, is a method of increasing the
fire blocking in the gusset between the pillow and mattress to
compensate for the more intense flame experience in this area.
SUMMARY OF THE INVENTION
[0009] This invention relates to a fire blocked pillow-top mattress
comprising a mattress body having a border comprising a first fire
blocker, a pillow for said mattress, and a gusset covering the
joint between the mattress body and the pillow, wherein the gusset
includes a second fire blocker that has a higher basis weight than
the first fire blocker.
[0010] This invention also relates to a fire blocked pillow-top
mattress comprising a mattress body having a border comprising a
first fire blocker comprising one or more fabric layers, the first
fire blocker having a first thermal performance temperature (TPT);
a pillow for said mattress; and a gusset covering the joint between
the mattress body and the pillow wherein the gusset includes a
second fire blocker comprising one or more layers and having a
lower TPT than the first fire blocker.
[0011] Another embodiment of this invention relates to a fire
blocked pillow-top mattress comprising a mattress body having a
seam connecting a panel of the mattress body and a side border, the
side border having fire blocking; a pillow having a seamed outer
edge; the pillow having a contact point with the mattress body
panel inboard from the side border of the mattress body, the seamed
outer edge of the pillow also extending outboard above such contact
point, wherein the area extending from the seam of the mattress
body across the mattress body panel to the pillow contact point and
up the underside of the pillow surface to the seamed outer edge of
the pillow has more fire blocking than that found in the mattress
side border.
[0012] This invention further relates to a process for fire
blocking a pillow-top mattress comprising a mattress body having a
side border and a pillow having a top panel, with a gusset attached
to the mattress body and the pillow, comprising the steps of
incorporating a first fire blocker into the mattress side border
and incorporating a second fire blocker into the gusset, wherein
the second fire blocker has either a higher basis weight than the
first fire blocker, or a lower TPT than the first fire blocker.
[0013] Another embodiment of this invention relates to a process
for fire blocking a pillow-top mattress comprising a mattress body
having a side border and a pillow having a top panel, with a gusset
attached to the mattress body and the pillow, comprising the steps
of incorporating a single layer of a fire blocker fabric into the
mattress side border and incorporating a plurality of layers of a
fire blocker fabric into the gusset.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a simplified cross-sectional view of a
single-sided pillow top mattress.
[0015] FIG. 2 is a more detailed cross-sectional view of a gusset
and border of a single-sided pillow-top mattress.
[0016] FIG. 3 is a detailed cross-sectional view of a single-sided
pillow-top mattress showing the placement of fire blocking quilted
composites.
[0017] FIGS. 4A, 4B, and 4C illustrate examples of the layering of
quilted composites incorporating fire blockers, expanded for
clarity.
[0018] FIGS. 5A, 5B, 5C, 5D, and 5E illustrate examples of the
layering of quilted composites incorporating two fire blocking
layers, expanded for clarity.
[0019] FIG. 6 illustrates, in a simplified manner, the arrangement
of burners, and a single-sided pillow top mattress and foundation
used to test the burn performance of a mattress set containing the
gusset of this invention.
[0020] FIG. 7 illustrates, in a simplified manner, the offset of
the arrangement of burners used to burn the single-sided pillow top
mattress set containing the gusset of this invention.
DETAILS OF THE INVENTION
[0021] This invention relates to an improved gusset for use in fire
blocking a pillow-top mattress and a fire blocked pillow-top
mattress containing this improved gusset. This gusset provides
additional fire blocking to provide a pillow-top mattress with
improved performance when tested according to Technical Bulletin
603 of the State of California.
[0022] FIG. 1 illustrates a single-sided pillow-top mattress 1.
This mattress is comprised of a pillow 2 attached to a mattress
body 3. The pillow typically comprises foam and/or fiber batting, a
nonwoven stitch backing, and cover fabric. The mattress body
includes mattress internals and coverings. The mattress internals
include the mechanical structure of the mattress, such as
supporting beams and springs and associated wrappings along with
additional foam, or combinations of foams and battings. The
mattress internals may also be only foam or other support
materials, such as an air or liquid bladder with or without
supporting foam, in the place of springs and other mechanical means
of support. The coverings for the mattress internals are generally
in the form of quilted composites or combinations of quilted
composites and additional foam or batting. FIG. 1 also shows an
indentation 4 in the side of the mattress at the point where the
pillow is attached inboard of the mattress body.
[0023] FIG. 2 illustrates in more detail the indentation area 4 of
a single sided pillow top mattress of FIG. 1. A gusset 8 covers the
joint 10 between the pillow and the mattress body. The gusset 8
includes an upper gusset surface 8a seamed to the pillow at seam 6
and at joint 10; and a lower gusset surface 8b seamed to the
mattress body at seam 7 and at joint 10. The upper surface 11 of
the pillow 2 is referred to as the top panel of the mattress. The
top panel 11 is delineated from the upper gusset surface 8a by the
upper gusset seam 6. The bottom surface 12 of the mattress body 3
is referred to as the bottom panel of the mattress. The vertical
surface of the mattress body 9 is referred to as the mattress
border. The border 9 is delineated from the lower gusset surface 8b
by the lower gusset seam, 7.
[0024] Fire blocking of the mattress prevents the batting or foam
from being ignited, or if the foam is ignited, suppresses the
spread of the flame in the supporting foam. In order to prevent the
fiber and foam from being ignited, the outer surfaces a mattress
that will come in contact with the flame are typically provided
with a fire blocker. For the single sided pillow top mattress
style, this includes the upper panel 11, the border 9, the gusset 8
and the lower panel 12. In some cases where a tight fit is achieved
between mattress and the foundation the lower panel does not
require a fire blocker.
[0025] A double-sided pillow top mattress is one that comprises two
pillows, one attached to the top and bottom panels of the mattress
body. In this case, the mattress will have 2 gussets and the outer
surfaces of the pillows will form the top and bottom panels of the
mattress. In this case it is normally necessary to fire block both
upper and lower panels and both upper and lower gussets in addition
to the mattress body border.
[0026] To quantify the flammability performance of mattress sets
the State of California published Technical Bulletin 603
"Requirements and Test Procedure for Resistance of a Residential
Mattress/Box Spring Set to a Large Open-Flame". In general, the
test protocol utilizes a pair of propane burners to subject the top
panel and one side border of a mattress or mattress/foundation set
to high heat flux in the form of flame jets. It is more difficult
for a pillow top mattress to past the test than a non-pillow top
mattress, because during the test, the flame jet from the side
burner impacts the border 9 of the mattress and the rising heat and
flames tend to concentrate in the gusset area, and it is believed
this causes the underside of the pillow in the indentation (gusset
area 8a) to experience a more intense flame experience than the
border 9 of the mattress, which typically results in the failure of
the otherwise adequately fire blocked mattress.
[0027] It is thought the more intense flame experience in the
gusset is due to not only the flames impinging the area from the
side burner jet but also from the upward flames generated from the
burning of the border, causing the material in the gusset area 8b
to also burn and in turn impinge on the underside of gusset area
8a.
[0028] The outer surfaces of mattresses, that is, the gussets,
borders and panels, are typically a layer of pre-stitched quilted
composite materials comprising a cover fabric, fiber and/or foam
and a stitch backing. In a fire blocked mattress, the quilted
composite material described above will preferably contain one or
more layers of a fire blocker. Referring to FIG. 3, single-sided
pillow-top mattress having a pillow 2 is shown attached to a
mattress body 3. In a typical construction of this invention,
mattress body 3 is provided with a fire blocking quilted composite
20 on the border and optionally fire blocking quilted composite 21
on the bottom panel. Quilted composites 20 and 21 may be the same
or different. The gusset between the mattress body and the pillow
is provided with fire blocking quilted composite 22, with the upper
gusset surface 22a attached to the pillow and lower gusset surface
22b attached to the mattress body. The pillow 2 is provided with
fire blocking quilted composite 24 over its top panel. Note that
the internal contact area 25 between the pillow and the mattress
body typically is not provided with a fire blocking quilted
composite, and is generally not needed. However, one may be added
there if desired.
[0029] The pre-stitched quilted composites can be in have many
forms. A basic example of a quilted composite is shown in FIG. 4A.
Quilted composite 30 is shown comprising an outer fabric ticking or
cover fabric layer 31, a fire blocker 32, a cushioning layer of
foam or fiber batting 33, and a stitch-backing layer 34. Fabrics
useful as the outer fabric ticking or cover fabric layer 31 are
normally very durable woven or knit fabrics utilizing any number of
weaves, and tend to have basis weights in the range of 2 to 8
ounces per square yard (68 to 271 grams per square meter). Ticking
fabrics may contain but are not limited to cotton, polyester
fibers, polypropylene fibers, or rayon fibers.
[0030] The fire blocker 32 is preferably a single layer nonwoven
sheet comprised of at least 0.5 ounces per square yard (17 grams
per square meter) of a cellulose fiber that retains at least 10
percent of its fiber weight when heated in air to 700.degree. C. at
a rate of 20 degrees C. per minute, and at least 0.5 ounces per
square yard (17 grams per square meter) of heat resistant fiber.
The nonwoven fire-blocking sheet preferably has a basis weight of
at least 2.5 ounces per square yard (85 grams per square meter).
Single layer nonwoven sheets having basis weights of less than that
amount do not provide adequate fire-blocking performance. The
maximum practical basis weight of a single layer nonwoven
fire-blocking sheet is in the range of 7 ounces per square yard.
Heavier weight fabrics still provide protection, however, with
additional basis weight there is little improvement in fire
retarding performance.
[0031] The nonwoven fire-blocking sheet can be made by conventional
nonwoven sheet forming processes, including processes for making
air-laid nonwovens or wet-laid nonwovens, and such formed sheets
can be consolidated via spunlacing, hydrolacing, needlepunching, or
other processes which can generate a nonwoven sheet. The spunlaced
processes disclosed in U.S. Pat. No. 3,508,308 and U.S. Pat. No.
3,797,074; and the needlepunching processes disclosed in U.S. Pat.
No. 2,910,763 and U.S. Pat. No. 3,684,284 are examples of methods
well known in the art that are useful in the manufacture of the
nonwoven fabrics. The preferred nonwoven sheets used in this
invention are air-laid spunlaced or hydrolaced nonwovens where high
pressure water jets are used to entangle fibers into a cohesive
sheet.
[0032] The cellulose fiber preferably used in the fire-blocking
sheet is a char-forming cellulose fiber. By char-forming, it is
meant the cellulose fiber retains at least 10 percent of its weight
when heated in air to 700.degree. C. at a rate of 20 degrees C. per
minute. Such cellulose fibers preferably have equal to or greater
than 10 percent inorganic compounds incorporated into the fibers.
Such fibers, and methods for making such fibers, are generally
disclosed in U.S. Pat. No. 3,565,749 and British Pat. No. GB
1,064,271. A preferred char-forming cellulose fiber for this
invention is a viscose fiber containing hydrated silicon dioxide in
the form of a polysilicic acid with aluminum silicate sites. Such
fibers, and methods for making such fibers are generally disclosed
in U.S. Pat. No. 5,417,752 and PCT Pat. Appl. WO9217629. Viscose
fiber containing silicic acid and having approximately 31 (.+-.3)
percent inorganic material is sold under the trademark Visil.RTM.
by Sateri Oy Company of Finland. These char-forming fibers, when
incorporated into the nonwoven sheet, provide adequate
fire-blocking performance without the need for the fabric to be
treated with additional flame-retardant additives or
topically-applied flame retardant compounds.
[0033] The heat resistant fiber is preferably an organic fiber, and
by "heat resistant" it is meant that the fiber preferably retains
90 percent of its fiber weight when heated in air to 500.degree. C.
at a rate of 20 degrees C. per minute. Such fibers are normally
flame resistant, meaning the fiber or a fabric made from the fiber
has a Limiting Oxygen Index (LOI) such that the fiber or fabric
will not support a flame in air, the preferred LOI range being
greater than 26. The preferred fibers do not excessively shrink
when exposed to a flame, that is, the length of the fiber will not
significantly shorten when exposed to flame. Sheets containing 0.5
ounces per square yard (17 grams per square meter) of an organic
fiber that retains 90 percent of its fiber weight when heated in
air to 500.degree. C. at a rate of 20 degrees C. per minute tend to
have limited amount of cracks and openings when burned by an
impinging flame.
[0034] Heat resistant and stable fibers useful in the nonwoven
fire-blocking sheets of this invention include fiber made from
para-aramid, polybenzazole, polybenzimidazole, and polyimide
polymer. The preferred heat resistant fiber is made from
para-aramid polymer.
[0035] As used herein, "aramid" is meant a polyamide wherein at
least 85% of the amide (--CONH--) linkages are attached directly to
two aromatic rings. Additives can be used with the aramid. In fact,
it has been found that up to as much as 10 percent, by weight, of
other polymeric material can be blended with the aramid or that
copolymers can be used having as much as 10 percent of other
diamine substituted for the diamine of the aramid or as much as 10
percent of other diacid chloride substituted for the diacid
chloride of the aramid. In the practice of this invention, the
preferred para-aramid is poly(paraphenylene terephthalamide).
Methods for making para-aramid fibers useful in this invention are
generally disclosed in, for example, U.S. Pat. Nos. 3,869,430,
3,869,429, and 3,767,756. Such aromatic polyamide organic fibers
and various forms of these fibers are available from DuPont
Company, Wilmington, Del. under the trademark Kevlar.RTM.
fibers.
[0036] Commercially available polybenzazole fibers useful in this
invention include Zylon.RTM. PBO-AS
(Poly(p-phenylene-2,6-benzobisoxazole) fiber, Zylon.RTM. PBO-HM
(Poly(p-phenylene-2,6-benzobisoxazole)) fiber, available from
Toyobo, Japan. Commercially available polybenzimidazole fibers
useful in this invention include PBI.RTM. fiber available from
Celanese Acetate LLC. Commercially available polyimide fibers
useful in this invention include P-84.RTM. fiber available from
LaPlace Chemical.
[0037] The nonwoven sheets used in the fire blocker can include, in
addition, an off gassing material that releases a flame suppressing
gas when burned. The preferred off gassing material are fibers made
from halogen-containing polymers, such as modacrylic fiber or
polyvinyichloride fibers. These polymers release
chlorine-containing gases when burned. Up to 4 ounces per square
yard (136 grams per square meter) of such materials can be added to
the single layer nonwoven fabric. Useful modacrylic fibers include,
but are not limited to, those disclosed in U.S. Pat. No.
5,506,042
[0038] The cushioning layer of foam or fiber batting 33 may include
one or more light density fibrous batting or foams, or a
combination thereof that provide the surface effect that is highly
desired by the consumer. The batting and/or foams acts like a
pillow underneath the ticking, providing very tactile cushioning,
the type that can be readily discerned by simply touching or
running one's hand across the mattress. The preferred fibrous
batting material is polyester (PET) batting and is typically
present in an amount of about 0.5 to 2.0 ounces per square yard (17
to 68 grams/square meter). While not intended to be limiting, if
the cushioning material is a fibrous batting, such batting may
include a vertically pleated structure such as disclosed in, for
example, in PCT Publication WO2003049581 or a batting of fibers
such as disclosed for example in U.S. Pat. No. 3,118,750. If foam
is used, it is commonly polyurethane or latex foam and is generally
about 1 to 3 inches thick.
[0039] The quilted composite illustrated in FIG. 4A also has a
stitch backing layer 34, which is a fabric layer used to hold the
stitch on the side opposite the ticking. Typically, stitch backing
layers are typically lightweight fabrics made from polypropylene
and having a basis weight in the range of 0.5 ounces per square
yard (17 grams per square meter). The layers shown in FIG. 4A are
combined and then stitched together using any common stitch
pattern, typically a quilting pattern, to form a quilted composite
structure that is then seamed together to cover the mattress
border, panels, or gussets as needed.
[0040] While not intended to be limiting, there are many
alternative fire blocking quilted composites useful in this
invention. FIG. 4B illustrates and alternative quilted composite 35
having the combination of ticking 31, cushioning material 33, and
fire blocker 32 wherein the cushioning material is sandwiched
between the fire blocker and the ticking. In this quilted
composite, no stitch backing is needed because the fire blocker
serves the purpose of holding the stitch. FIG. 4C illustrates a
possible fire blocking quilted composite 36 having additional
cushioning material. The quilted composite is formed by combining,
in order, ticking fabric 31, a layer of cushioning material 33, a
fire blocker 32, another layer of cushioning material 33, and a
stitch backing layer 34.
[0041] The fire blocker used in these fire-blocking quilted
composites can include multiple layers of fire blocking material.
For example, FIG. 5A illustrates quilted composite 38 that is
similar to quilted composite 30 shown in FIG. 4A, except the fire
blocker 32 is comprised of two layers of material. Likewise, FIG.
5B illustrates quilted composite 39 and FIG. 5C illustrates quilted
composite 40, which are similar to quilted composites 35 and 36 of
FIGS. 4B and 4C, respectively, except that the fire blocker 32 is
comprised of two layers of material. It is not necessary that the
fire blocking layers be placed together. FIG. 5D shows a possible
quilted composite configuration 41 in which one upper fire blocking
layer 32 is directly under the cover fabric 31 and the second lower
fire blocking layer 32, functioning as a stitch backing, is under a
cushioning layer 33. FIG. 5E shows a quilted composite
configuration 42 similar to 41 with the addition that another
cushioning layer 33 is added between the cover fabric 31 and the
upper fire blocking layer 32.
[0042] One embodiment of the fire blocked pillow-top mattress of
this invention comprises a mattress body having a border comprising
a first fire blocker, a pillow for said mattress, and a gusset
covering the joint between the mattress body and the pillow,
wherein the gusset includes a second fire blocker that has a higher
basis weight than the first fire blocker. The second fire blocker
is generally at least 20 percent higher in basis weight, and
preferably at least 50 percent higher in basis weight. The
composition of the second fire blocker can be the same or different
from the first fire blocker. The top panel of the pillow is also
preferably fire blocked with a quilted composite containing a
suitable fire blocker. The gusset having the increased basis weight
provides sufficient fire resistance to the gusset area to allow the
mattress to pass when tested according to Technical Bulletin 603 of
the State of California.
[0043] Another embodiment of the fire blocked pillow-top mattress
of this invention comprises a mattress body having a border
comprising a first fire blocker comprising one or more fabric
layers, the first fire blocker having a first TPT; a pillow for
said mattress; and a gusset covering the joint between the mattress
body and the pillow wherein the gusset includes a second fire
blocker comprising one or more layers and having a lower TPT than
the first fire blocker. Preferably, the second fire blocker has a
TPT that is at least 50 degrees Celsius lower, and the composition
of the second fire blocker can be the same or different from the
first fire blocker. The top panel of the pillow is preferably fire
blocked with a quilted composite containing a suitable fire
blocker.
[0044] Thermal performance, as used herein, is characterized by the
TPT of the fabric, which is a value that is directly proportional
to the amount of heat that passes through the barrier fabric. Low
TPT values mean the fire blocker is a good insulator from flame and
will help prevent the internals of a mattress from the heat from an
external flame.
[0045] The TPT can be reduced in any number of ways. If the fabric
composition is not changed, the TPT can be reduced by increasing
the basis weight of the fabric, or by combining two or more sheets
of fire blocking material. Conversely, the fabric used in the
gusset area can be different from that used in the border, and,
depending on the composition, may be the same, or heavier or
lighter in basis weight to the fire blocker in the border. A third
possible method of reducing the TPT can be achieved by changing the
structure of the fire blocker, that is, by reducing the volumetric
density, weaving or knitting the fire blocking sheets versus using
nonwoven sheets, or combining woven or knitting sheets with
nonwoven sheets, or using specialty weaves and the like, that
through testing have shown can decrease the TPT. A fourth method of
reducing the TPT is through the use of coatings or additives that
would increase the flame retardancy of the fire blocker used in the
gusset. Specifically, intumescent coatings or fire blocking
coatings such as Thermolose may be used.
[0046] The preferred fire blocked mattress contains a border having
a quilted composite containing, as a first fire blocker, one layer
of a nonwoven fire-resistant fabric and a gusset having a quilted
composite containing, as a second fire blocker, two layers of that
same nonwoven fire-resistant fabric. This eliminates the need for
two types of fire blocker fabric compositions and allows one to
easily check that the gusset has additional fire blocking by the
presence of two layers.
[0047] This gusset provides additional fire blocking to provide a
pillow-top mattress with improved performance when tested according
to Technical Bulletin 603 of the State of California.
[0048] Another embodiment of the fire blocked pillow-top mattress
of this invention comprises a mattress body having a seam
connecting a panel of the mattress body and a side border, the side
border having fire blocking; an attached pillow having a seamed
outer edge, said pillow having a contact point with the mattress
inboard from the side border of the mattress, the seamed outer edge
of said pillow also extending outboard above such contact point and
the area extending from the seam of the mattress body across the
mattress body panel to the pillow contact point and up the
underside of the pillow surface to the seamed outer edge of the
pillow having more fire blocking than that found in the mattress
side border. "More fire blocking" can include the concepts
previously mentioned, including having more fire blocking material
in the gusset area, or providing the gusset area with fire blocking
material having a lower TPT than the border fire blocking material.
Preferably the top panel of the pillow is also fire blocked with a
quilted composite containing a nonwoven fabric fire blocker.
[0049] This invention further relates to a process for fire
blocking a pillow-top mattress comprising a mattress body having a
side border and a pillow having a top panel, with a gusset covering
the joint between the mattress body and the pillow, comprising the
steps of incorporating a first fire blocker into the mattress side
border and incorporating a second fire blocker into the gusset,
wherein the second fire blocker has either a higher basis weight
than the first fire blocker, or a lower TPT than the first fire
blocker. The top panel of the pillow is preferably fire blocked
with a quilted composite containing either the first or second fire
blocker. Preferably the first and second fire blockers are nonwoven
fabrics.
[0050] Another embodiment of this invention relates to a process
for fire blocking a pillow-top mattress comprising a mattress body
having a side border and a pillow having a top panel, with a gusset
covering the joint between the mattress body and the pillow,
comprising the steps of incorporating a single layer of a fire
blocker fabric into the mattress side border and incorporating a
plurality of layers of a fire blocker fabric into the gusset. The
fire blocker fabric used in the border and the gusset are
preferably the same fabric.
Test Methods
[0051] Mattress Burn Performance. The Bureau of Home Furnishings
and Thermal Insulation of the Department of Consumer Affairs of the
State of California (3485 Orange Grove Avenue, North Highlands,
Calif. 95660-5595, USA) published Technical Bulletin 603
"Requirements and Test Procedure for Resistance of a Residential
Mattress/Box Spring Set to a Large Open-Flame" dated November 2003
to quantify the flammability performance of mattress sets. This
protocol provides a means of determining the burning behavior of
mattress/foundation sets by measuring specific fire test responses
when the mattress plus foundation are exposed to a specified
flaming ignition source under well-ventilated conditions. It is
based on the National Institute of Standards and Technology
Publication titled "Protocol of Testing Mattress/Foundation Sets
Using a Pair of Gas Burners" dated February 2003.
[0052] Test data are obtained that describe the burning during and
subsequent to the application of a specific pair of gas burners
from the point of ignition until (1) all burning of the sleep set
has stopped, (2) a period of one hour has elapsed, or (3) flashover
of the test room appears inevitable. The rate of heat release from
the burning test specimen (the energy generated by the fire) is
measured by oxygen consumption calorimetry. A discussion of the
principles, limitations, and requisite instrumentation are found in
ASTM E 1590 "Standard Test Method of Fire Testing of Mattresses".
Terminology associated with the testing is defined in ASTM E 176
"Standard Terminology of Fire Standards".
[0053] In general, the test protocol utilizes a pair of propane
burners, designed to mimic the heat flux levels and durations
imposed on a mattress and foundation by burning bedclothes. The
burners impose differing fluxes for differing times on the mattress
top and the side of the mattress/foundation. During and subsequent
to this exposure, measurements are made of the time-dependent heat
release rate from the test specimen.
[0054] The mattress/foundation is placed on top of a short bed
frame that sits on a catch surface. During the testing, the smoke
plume is caught by a hood that is instrumented to measure heat
release rate. For practicality, twin-sized mattresses and
foundations are tested. After ignition by the burners, the specimen
is allowed to burn freely under well-ventilated conditions.
[0055] A representative illustration of the general locations of
the gas burners, not drawn to scale, is shown in FIG. 7. Test
specimen 20 includes a pillow top mattress 21 is placed on
foundation 22 with T-shaped burners 23 and 24 set to burn the
specimen. Burner 23 impinges flames on the top surface of the
mattress and is set 39 mm from the surface of the mattress. The
second burner 24 impinges flames vertically on the side of the
mattress/foundation combination and is set 42 mm from the side of
the specimen. The side burner and the top burner are not set at the
same place along the length of the specimen but are offset from on
another along the length approximately 18 to 20 cm as generally
illustrated in FIG. 8. The burners are specially constructed and
aligned per the test method.
[0056] The test specimen is conditioned for 24 hours prior to the
testing at an ambient temperature of above 12 Celsius (54
Fahrenheit) and a relative humidity of less than 70 percent. The
test specimen of mattress and foundation is centered on each other
and the frame and catch surface. If the mattress is 1 to 2 cm
narrower than the foundation the mattress may be shifted until the
sides of the mattress and foundation are aligned vertically. The
burners are aligned and spaced from the specimen per the standard.
Data recording and logging devices are turned on at least one
minute prior to ignition. The burners are ignited and the top
burner is allowed to burn for 70 seconds while the side burner is
allowed to burn for 50 seconds and then they are removed from the
area. Data collection continues until all signs of burning and
smoldering have ceased or until one hour has elapsed.
[0057] ThermoGravametric Analysis. The fibers used in this
invention retain a portion of their fiber weight when heated to
high temperature at a specific heating rate. This fiber weight was
measured using a Model 2950 Thermogravimetric Analyzer (TGA)
available from TA Instruments (a division of Waters Corporation) of
Newark, Del. The TGA gives a scan of sample weight loss versus
increasing temperature. Using the TA Universal Analysis program,
percent weight loss can be measured at any recorded temperature.
The program profile consists of equilibrating the sample at 50
degrees C.; ramping the temperature at from 10 or 20 degrees C. per
minute from 50 to 1000 degrees C.; using air as the gas, supplied
at 10 ml/minute; and using a 500 microliter ceramic cup (PN
952018.910) sample container.
[0058] The testing procedure is as follows. The TGA was programmed
using the TGA screen on the TA Systems 2900 Controller. The sample
ID was entered and the planned temperature ramp program of 20
degrees per minute selected. The empty sample cup was tared using
the tare function of the instrument. The fiber sample was cut into
approximately 1/16'' (0.16 cm) lengths and the sample pan was
loosely filled with the sample. The sample weight should be in the
range of 10 to 50 mg. The TGA has a balance therefore the exact
weight does not have to be determined beforehand. None of the
sample should be outside the pan. The filled sample pan was loaded
onto the balance wire making sure the thermocouple is close to the
top edge of the pan but not touching it. The furnace is raised over
the pan and the TGA is started. Once the program is complete, the
TGA will automatically lower the furnace, remove the sample pan,
and go into a cool down mode. The TA Systems 2900 Universal
Analysis program is then used to analyze and produce the TGA scan
for percent weight loss over the range of temperatures.
[0059] Thermal Performance Temperature. The thermal insulating
properties of these fabrics at high temperatures and heat fluxes
was measured using the same instrument that is used for the NFPA
1971 Standard on Protective Ensemble for Structural Fire Fighting
2000 Edition Section 6-10. In order to characterize the materials
of this invention, the instrument was operated in a data
acquisition mode. A 2 cal/cm.sup.2/second (8.38 J/cm.sup.2/second)
heat flux was imposed on the fabric for 90 seconds. During this
time, the heat passing through the materials was measured using a
calorimeter placed in direct contact with the back face (base
layer) of the specimen. The materials were characterized in terms
of the temperature of the calorimeter thermocouple at the end of
the 90 seconds exposure. This value is directly proportional to the
amount of heat that passed through the barrier fabric.
[0060] Basis Weight. Basis weight of the batting was measured using
ASTM D6242-98.
[0061] Thickness. Thickness of the layered batting was measured
using ASTM D5736-95 (Reapproved 2001).
EXAMPLE
[0062] Three sleep sets, each comprised of a pillow top mattress
and foundation, were made using typical mattress and box spring
construction techniques, each set only differing in the level of
fire-blocking fabric used in the gusset.
[0063] The foundation was a standard steel coil and wood box
construction. The mattress body was a standard steel coil
construction covered with a fiber pad and a 0.5-inch (1.25
centimeter) foam sheet.
[0064] Panel material for the mattresses was assembled by quilting
together with standard polyester thread the following components in
the order: 3.5 ounces per square yard (119 grams per square meter)
woven polyester/propylene blend ticking fabric, a single layer of
fire blocking fabric "A" from Table 1, approximately 0.75 inch
(1.91 cm) polyester batting having an basis weight of 0.75 ounces
per square yard (25 grams per square meter), three 0.5 inch (1.25
cm) polyurethane foam sheets, and a nonwoven backing sheet of
approximately 1 ounces per square yard (34 grams per square meter).
This panel material was used to cover the top panel of the pillow.
TABLE-US-00001 TABLE 1 Fire Blocking Fabric Identification
Description A 2.5 ounces per square yard (85 grams per square
meter) spunlaced nonwoven fabric having a composition of 50% Kevlar
.RTM. brand aramid fiber and 50% Visil .RTM. FR viscose fiber onto
which 4.0 ounces per square yard (136 grams per square meter) have
been needled felted having a composition of 67% Protex C modacrylic
fiber and 33% Visil .RTM. FR viscose fiber B 3.0 ounces per square
yard (102 grams per square meter) spunlaced nonwoven fabric100%
having a composition of 100% Kevlar .RTM. aramid fiber C 4.5 ounces
per square yard (153 grams per square meter) spunlaced nonwoven
fabric having a composition of 25% Kevlar .RTM. aramid fiber, 25%
Nomex .RTM. aramid fiber and 50% Protex C modacrylic fiber.
[0065] Border material was assembled in a separate operation by
quilting together with standard polyester thread the following
components in the order: 3.5 ounces per square yard (119 grams per
square meter) woven polyester/polypropylene blend ticking fabric, a
single layer of the same fire blocking fabric "A" from Table 1,
approximately 0.375'' polyurethane foam having an basis weight of
2.5 ounces per square yard (85 grams per square meter) and a
nonwoven backing sheet of approximately 1 ounces per square yard.
The border material was used to cover all four borders (vertical
sides) of the mattresses. The same border material described above
was also used on the four vertical sides of the foundation
employing a 2 inch (5.1 centimeter) continental or waterfall design
on the upper edge of the foundation, a design in which the border
material is folded over the upper edge and extends onto the
foundation top panel.
[0066] The foundation top panel area within the continental edge
was covered with a 4 ounces per square yard (136 grams per square
meter) of spunlaced nonwoven fabric (having a composition of 25%
Kevlar.RTM.) aramid fiber and 75% Visil.RTM. FR viscose) under a
standard non-skid pad. All border and panel composite material
seams were sewed with a thread containing Kevlar.RTM.) aramid
fiber. FR-treated polyester seam tape was also used throughout.
[0067] In order to form the material used for the gusset, an
additional layer of fire blocking fabric "B" or "C" from Table 1
was serged onto the back of the same border material used in the
foundation and mattress borders and described above such that the
added blocking fabric was in contact with the 1 ounces per square
yard (34 grams per square meter) backing sheet.
[0068] The TPT of the fire blockers was measured. The results are
shown in Table 2. TABLE-US-00002 TABLE 2 Fire Blocking Fabric
Identification TPT, .degree. C. A 346 B 409 C 429
[0069] The three sleep sets were individually burned according to
Technical Bulletin 603 of the State of California. Burn results are
summarized in Table 3. The set without any additional fire blocker
in the gusset (Example 1) exceeded 150 kW heat release rate in 27
minutes. The sets that had additional fire blocking in the gusset
did not exceed 150 kW through the entire 60 minutes that the heat
release rate was monitored. TABLE-US-00003 TABLE 3 Time to exceed
150 kW heat release Example Fire blocker in gusset rate 1 A 27
minutes (comparative) 2 A plus B (see Table 1) Did Not 3 A plus C
(see Table 1) Did Not PHRR = Peak Heat Release Rate THR = Total
Heat Release
[0070] For the examples shown above, the TPT of the gusset was
reduced by using an additional layer of a second fire blocking
fabric. It would have been possible to obtain the same result by
using two layers of fire blocking fabric "A". Another method of
increasing the TPT is to use a fabric of high basis weight. The
fact that the TPT decreases with basis weight is shown clear by the
following series of spunlaced fabrics composed of approximately 25%
Kevlar.RTM.) aramid fiber, 42% Visil.RTM. FR and 33% Protex C
modacrylic fiber. Within this series the TPP rating increases
approximately proportionately with the basis weight. TABLE-US-00004
Basis weight, ounces per square Example yard (grams per square
meter) TPT, .degree. C. 4 2.5 (85) 471 5 3.8 (129) 434 6 5.0 (169)
393 7 6.5 (220) 346
* * * * *