U.S. patent application number 11/778523 was filed with the patent office on 2010-02-04 for fire combustion modified batt.
This patent application is currently assigned to L&P PROPERTY MANAGEMENT COMPANY. Invention is credited to Steven E. Ogle, Karl Van Becelaere.
Application Number | 20100029163 11/778523 |
Document ID | / |
Family ID | 41608832 |
Filed Date | 2010-02-04 |
United States Patent
Application |
20100029163 |
Kind Code |
A1 |
Ogle; Steven E. ; et
al. |
February 4, 2010 |
Fire Combustion Modified Batt
Abstract
A high loft fiber batt is formed from a blend comprising charred
thermoplastic fibers and about 10-15 percent by volume polyester
binder fibers, wherein the fiber batt is suitable for use as a fire
barrier layer. Another embodiment of a high loft fiber batt is
formed from a blend of at least 15 percent by volume charred
thermoplastic fibers, at least 15 percent by volume polyester
carrier fibers, and about 10-15 percent by volume polyester binder
fibers. Still another embodiment of a high loft fiber batt
comprises a blend of about equal amounts by volume of charred
thermoplastic fibers and polyester carrier fibers, wherein the
fiber batt is suitable for use as a fire barrier layer. These high
loft fiber batts may be used as a fire barrier layer in various
different products, including seating and insulation for vehicles
and aircraft, bedding, upholstery and furniture.
Inventors: |
Ogle; Steven E.; (Cary,
NC) ; Van Becelaere; Karl; (Nashville, TN) |
Correspondence
Address: |
CONLEY ROSE, P.C.
5601 GRANITE PARKWAY, SUITE 750
PLANO
TX
75024
US
|
Assignee: |
L&P PROPERTY MANAGEMENT
COMPANY
South Gate
CA
|
Family ID: |
41608832 |
Appl. No.: |
11/778523 |
Filed: |
July 16, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10968318 |
Oct 18, 2004 |
7244322 |
|
|
11778523 |
|
|
|
|
10221638 |
Jan 7, 2003 |
7147734 |
|
|
PCT/US01/07831 |
Mar 13, 2001 |
|
|
|
10968318 |
|
|
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|
60188979 |
Mar 13, 2000 |
|
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|
Current U.S.
Class: |
442/414 |
Current CPC
Class: |
B32B 2262/04 20130101;
B32B 5/26 20130101; D04H 1/43 20130101; B32B 2479/00 20130101; B32B
2605/08 20130101; B32B 2307/3065 20130101; Y10T 442/696 20150401;
B32B 2250/20 20130101; B32B 2262/02 20130101; B32B 2605/00
20130101; B32B 2601/00 20130101; B32B 5/08 20130101; B32B 2605/18
20130101; B32B 2605/003 20130101; B32B 2262/14 20130101; D04H
1/4258 20130101; B32B 2262/0276 20130101; D04H 1/559 20130101; D04H
1/55 20130101; B32B 5/022 20130101 |
Class at
Publication: |
442/414 |
International
Class: |
D04H 13/00 20060101
D04H013/00 |
Claims
1. A high loft fiber batt formed from a blend comprising: charred
thermoplastic fibers; and about 10-15 percent by volume polyester
binder fibers; wherein the fiber batt is suitable for use as a fire
barrier layer.
2. Products using the fiber batt of claim 1 as a fire barrier layer
thereof.
3. The products of claim 2 wherein the products are selected from
the group consisting of vehicle seating, aircraft seating, vehicle
wall insulation and aircraft wall insulation.
4. The products of claim 2 wherein the products are selected from
the group consisting of bedding, upholstery and furniture.
5. Aircraft using the fiber batt 1 as a fire barrier layer
thereof.
6. Vehicles using the fiber batt 1 as a fire barrier layer
thereof.
7. The fiber batt of claim 1 wherein the blend comprises at least
15 percent by volume of the charred thermoplastic fibers.
8. The fiber batt of claim 1 wherein the blend further comprises at
least 15 percent by volume polyester carrier fibers.
9. The fiber batt of claim 8 wherein the blend comprises about
equal amounts by volume of the charred thermoplastic fibers and the
polyester carrier fibers.
10. The fiber batt of claim 1 wherein the charred thermoplastic
fibers are selected from the group consisting of oxidized
polyacrylonitrile fibers and FR rayon fibers.
11. A high loft fiber batt formed from a blend of at least 15
percent by volume charred thermoplastic fibers, at least 15 percent
by volume polyester carrier fibers, and about 10-15 percent by
volume polyester binder fibers.
12. Products using the fiber batt of claim 11 as a fire barrier
layer thereof.
13. The products of claim 12 wherein the products are selected from
the group consisting of vehicle seating, aircraft seating, vehicle
wall insulation and aircraft wall insulation.
14. The products of claim 12 wherein the products are selected from
the group consisting of bedding, upholstery and furniture.
15. Aircraft using the fiber batt 11 as a fire barrier layer
thereof.
16. Vehicles using the fiber batt 11 as a fire barrier layer
thereof.
17. The fiber batt of claim 11 wherein the blend comprises about
equal amounts by volume of the charred thermoplastic fibers and the
polyester carrier fibers.
18. The fiber batt of claim 11 wherein the charred thermoplastic
fibers are selected from the group consisting of oxidized
polyacrylonitrile fibers and FR rayon fibers.
19. A high loft fiber batt comprising a blend of about equal
amounts by volume of charred thermoplastic fibers and polyester
carrier fibers, wherein the fiber batt is suitable for use as a
fire barrier layer.
20. The fiber batt of claim 19 wherein the blend further comprises
about 10-15 percent by volume polyester binder fibers.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation-In-Part of U.S. patent
application Ser. No. 10/968,318, filed Oct. 18, 2004, which is
based on and claims priority to U.S. patent application Ser. No.
10/221,638, filed Jan. 7, 2003, now U.S. Pat. No. 7,147,734, which
is based upon International Patent Application PCT US01/07831,
filed Mar. 13, 2001, which, in turn, is based on and claims
priority to U.S. Patent Application Ser. No. 60/188,979, entitled
Bi-Lofted Fire Combustion Modified Batt filed on Mar. 13, 2000.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
[0003] Not applicable.
FIELD OF THE INVENTION
[0004] Disclosed herein are fire combustion modified batts and
methods for forming such batts. More particularly, the fire
combustion modified batts disclosed herein comprise a blend of
nonwoven fibers and charred thermoplastic fibers, such as oxidized
polyacrylonitrile (PAN) or FR rayon fibers. The methods include
forming a blend of the nonwoven fibers and charred thermoplastic
fibers into a web. The charred thermoplastic fibers are fire
resistant, and when blended with nonwoven fibers, are relatively
easily processed into a batt. A second blend of nonwoven fibers can
be formed into a web and layered with the web of charred
thermoplastic fibers and nonwoven fibers to form the batt. The
fibers of the batt are bonded together with heat, resin or other
suitable bonding means and are compressed and cooled to set the
batt. The fire combustion modified batt is useful as a fire barrier
layer and filling in bedding, upholstery and vehicle and aircraft
seats, as insulators for apparel, appliances, walls, aircraft
walls, vehicle walls and ducting, as barriers to separate control
systems from a heat source, and as components in fire safety gear
such as race driver suits, oven and welding mitts, and the
like.
BACKGROUND
[0005] Fire retardant barriers are desirable for a wide variety of
applications. Products for household and public occupancies such as
health care facilities, convalescent care homes, college
dormitories, residence halls, hotels, motels and correctional
institutions are sometimes governed by regulations which require
certain fire resistant characteristics, particularly in bedding and
upholstery. Fire barrier components are also needed in apparel,
fire safety gear, vehicle and aircraft seating and walls, as
insulators for appliances, walls, ducting, as barriers to separate
sensitive controls from a heat source and other similar
applications where fire safety is a concern. Effective fire
barriers minimize the amount and rate of heat released from the
barrier upon contact with fire. The rate of beat released is an
indication of the intensity of the fire generated from the fire
barrier material as well as how quickly the fire spreads. Slowing
the spread of fire advantageously increases the amount of response
time for a fire victim to safely escape and a fire department to
successfully extinguish the fire.
[0006] In the bedding, upholstery and other industries, foams and
nonwoven fibers are used in mattresses, sofas, chairs, and seat
cushions, backs and arms. Traditionally, urethane foam has been
combined with other types of cushioning materials such as cotton
batting, latex rubber, and various nonwoven fibers in order to
impart desirable comfort, loft and durability characteristics to a
finished product. However, urethane foam is extremely flammable and
must be chemically treated or coated to impart fire resistant
properties to the foam. Alternatively, neoprene foam is used in
bedding and upholstery products as it is relatively fire resistant.
Both neoprene foam and urethane foam which have been treated for
fire resistancy are relatively expensive.
[0007] Synthetic and natural nonwoven fibers also have demonstrated
usefulness in the construction of mattresses and upholstery. Such
fibers are inherently lightweight and therefore easy to ship, store
and manipulate during processing. When subjected to open flame,
many synthetic fibers, particularly polymer fibers and specifically
dry polyester fibers, tend to melt and drip rather than burn. In
addition, polymer fibers can be coated for fire resistance. For
example, polymer fibers which have been treated for fire resistance
are identified in the industry under the names Trevira FR, Kevlar
and Nomex and are considered to be non-flammable.
[0008] Correctional institutions typically use three types of
cushion cores for mattresses. The cushion cores include foam,
densified synthetic nonwoven fiber which has a density of about 1.5
pounds per cubic foot or greater, and cotton batting. Left
untreated, cotton fibers are extremely flammable and burn rapidly.
Cotton can, however, be chemically treated, typically with boric
acid, to impart fire resistant properties to the cotton.
Correctional institutions with heightened fire safety concerns may
require their mattresses to meet certain fire safety standards. In
these cases, the cushion cores are comprised of neoprene foam or
cotton batting which has been treated with boric acid. However,
cotton is extremely moisture absorbent. Thus, mattresses comprised
of cotton are difficult to maintain in a hygienic condition.
Furthermore, cotton mattresses are relatively heavy.
[0009] Oxidized polyacrylonitrile (PAN) fibers, while fire
resistant, are difficult to process into batts for use as a barrier
layer or filling, particularly in bedding and upholstery
applications. The fibers are relatively low in weight and specific
gravity making traditional carding methods for forming batts
difficult. In addition, oxidized PAN fibers are so-called dead
fibers as they have relatively little resilience and loft and are
incompressible. In certain applications, in particular for bedding
and upholstery, a oxidized PAN fiber batt may be unsuitable where
comfort and loft are desired. Oxidized PAN fibers are also black in
color and thus may be unsuitable in applications which require a
light color beneath a light decorative upholstery or mattress
layer.
SUMMARY
[0010] Through significant time and effort, it has been found that
the difficulties associated with providing a fire barrier layer
could be avoided by the method and batt of the present invention.
As will be appreciated by one skilled in the art, the novel method
and batt are applicable to a wide variety of products, including as
barrier layers and filling materials in bedding and upholstery, as
wraps for and replacements of cushion and arms in furniture,
vehicle and aircraft seats, as insulators for apparel, appliances,
walls, vehicle walls, aircraft walls, ducts and to separate
sensitive controls from a heat source, and as components in fire
safety gear such as oven or welding mitts, and the like.
[0011] In one aspect, a high loft fiber batt disclosed herein is
formed from a blend comprising charred thermoplastic fibers and
about 10-15 percent by volume polyester binder fibers, wherein the
fiber batt is suitable for use as a fire barrier layer. In an
embodiment, the blend of the fiber batt comprises at least 15
percent by volume of the charred thermoplastic fibers. The blend
may further comprise at least 15 percent by volume polyester
carrier fibers. In an embodiment, the blend comprises about equal
amounts by volume of the charred thermoplastic fibers and the
polyester carrier fibers. The charred thermoplastic fibers may be
selected from the group consisting of oxidized polyacrylonitrile
fibers and FR rayon fibers.
[0012] In another aspect, a high loft fiber batt disclosed herein
is formed from a blend of at least 15 percent by volume charred
thermoplastic fibers, at least 15 percent by volume polyester
carrier fibers, and about 10-15 percent by volume polyester binder
fibers. In an embodiment, blend forming the fiber batt comprises
about equal amounts by volume of the charred thermoplastic fibers
and the polyester carrier fibers. The charred thermoplastic fibers
may be selected from the group consisting of oxidized
polyacrylonitrile fibers and FR rayon fibers.
[0013] In yet another aspect, a high loft fiber batt disclosed
herein comprises a blend of about equal amounts by volume of
charred thermoplastic fibers and polyester carrier fibers, wherein
the fiber batt is suitable for use as a fire barrier layer. In an
embodiment, the blend further comprises about 10-15 percent by
volume polyester binder fibers.
[0014] Many different products may use the fiber batt as a fire
barrier layer thereof. In various embodiments, the products may be
selected from the group consisting of vehicle seating, aircraft
seating, vehicle wall insulation, aircraft wall insulation,
bedding, upholstery and furniture. An aircraft or a vehicle may
also use the fiber batt as a fire barrier layer thereof.
[0015] The method of forming the fiber batts disclosed herein
comprises blending carrier and binder nonwoven fibers and charred
thermoplastic fibers, such as oxidized polyacrylonitrile (PAN)
fibers or FR rayon fibers, to form a substantially homogeneous
blend of the fibers. The binder fibers have a relatively low
melting point and the carrier fibers have a relatively high melting
point. While the homogeneous mixture can be any of a number of
suitable blends, in one embodiment, the binder fiber can be
anywhere in the range of about 5 percent to 50 percent by volume of
the blend. The relative percent volume of charred thermoplastic
fibers to carrier fibers in the remaining blend volume ranges
anywhere from 15 percent to 85 percent. In a preferred embodiment,
the relative volume of charred thermoplastic fibers to carrier
fibers is about 50 percent to 50 percent. Thus, for a blend having
10 percent by volume of binder fibers and a 50 to 50 percent
relative volume of charred thermoplastic fibers to carrier fibers,
the volume of charred thermoplastic fibers and carrier fibers in
the blend is 45 percent each.
[0016] The blended fibers are formed into a batt by using a garnett
machine, cross layers, an air layer or any other suitable batt
forming apparatus. In a garnett and cross laying process, the blend
of fibers are formed into a web for transporting along a conveyor
moving in the machine direction. Successive web layers are layered
in the cross direction onto the conveyor in an progressive
overlapping relationship by moving one or more reciprocating
cross-lappers carrying the web back and forth between a first side
of the conveyor and an opposing second side.
[0017] The batt is positioned on an air permeable support and a
vacuum is applied through the air permeable support and batt from a
first side of the batt to an opposing second side of the batt. The
vacuum pressure is sufficient to substantially compress the web
into a desired thickness or loft and at a desired density. In an
alternative embodiment, the batt is compressed between opposing
counter rotating rollers proximate the machine direction and spaced
apart a predetermined distance to reduce the thickness and increase
the density of the batt. Heat is applied to the web structure at a
temperature sufficient to soften the binder fibers but low enough
to avoid melting the carrier fibers. The plastic memory of the
softened binder fibers is released in their compressed
configuration and the fibers fuse to themselves and to the other
web fibers to form a batt having interconnected and fused fibers.
The batt is cooled in its compressed state to reset the plastic
memory of the binder fibers and form a thermal bonded batt having a
density and thickness substantially the same as induced in the batt
by the vacuum pressure or compression.
[0018] In products which require additional loft, compressibility,
resilience and comfort or a light color beneath decorative
upholstery, a mattress quilt or other covering for aesthetic
purposes, an additional web comprising nonwoven fibers which are
light in color can be formed. A surface of the nonwoven web is
disposed to a surface of the blended charring fiber web to form a
batt which is heated, compressed and cooled together.
Alternatively, the charring fiber web and the nonwoven web can be
heated, compressed and cooled separately and then disposed together
to form the batt.
[0019] The thermal bonded batt has a wide variety of applications
in products, depending on its charring fiber content and the
density of the batt. For example, a batt having a density of less
than 1.5 pounds per cubic foot, defined herein as a high loft batt,
can be used as a fire barrier layer in mattresses and border panels
of mattresses and as a wrap for or an additional layer to cushion
seats, backs and arms in furniture, vehicle and aircraft seats.
Such high loft batts may also be used in applications such as
insulation for aircraft walls and vehicle walls, and otherwise used
in aircraft and vehicle applications. In mattresses and seats
having a light colored decorative covering, the batt comprising a
layer of nonwoven fibers would be positioned with the light colored
nonwoven layer proximate the decorative covering to shield it from
the dark color charring PAN fibers. The thermally bonded high loft
batt is also suitable as an insulation lining in apparel and fire
safety gear such as, for example, in fire fighter jackets and oven
mitts for welding or industrial furnace purposes. Further, the high
loft batt is suitable as a fire barrier air filter and as an
insulator for appliances such as hot water tanks and furnaces. Wall
insulation and insulation in recreational vehicle wall cavities are
also suitable applications of the high loft batt.
[0020] Batts formed from the method of the present invention having
a density of about 1.5 pounds per cubic foot or greater, defined
herein as densified, are suitable as a replacement to cushion
backs, seats and arms in furniture, vehicle and aircraft seats. The
densified batts are also suitable in toppers and filling in
mattresses, as well as replacements for mattress cores, such as,
for example, the foam or inner springs in mattresses, particularly
for use in public occupancies and correctional institutions.
Additionally, densified batts are suitable for insulation lining in
apparel and safety gear such as race driver suits, and as
insulation for walls, furnace wall insulation, and ducting
insulation. Densified batts are particularly suitable for sound
deadening and thermal transfer applications.
[0021] In yet another embodiment of the method of the present
invention, a resin is used to bond carrier fibers and charred
thermoplastic fibers to form a fire combustion modified batt of the
resent invention. In this embodiment, carrier fibers having a
relatively high melting point are blended with the charred
thermoplastic fibers to form a homogeneous mixture. While the
homogeneous mixture can be any of a number of suitable blends, the
charred thermoplastic fibers can be in the range of about 15
percent to 100 percent by volume of the batt and, accordingly, the
volume of carrier fibers would be from 85 percent to a negligible
amount. Thus, for a blend having 85 percent charred thermoplastic
fibers, the volume of carrier fibers would be about 15 percent. The
blended charring and carrier fibers can be formed into a web
generally according to the garnett method for forming the thermally
bonded web described herein. An air laying machine can also be
used. Generally, the fibers are introduced into an air stream which
carries the fibers to an air permeable support such as a perforated
drum which is rotating. Accumulation of the fibers onto the drum
surface results in a web formation. A vacuum is applied through the
web from one side of the web to the other and through said air
permeable support sufficient to reduce the thickness and increase
the density of the web throughout the thickness of the web to form
a batt. The batt is saturated with a heat curable resin which can
additionally comprise fire resistant properties to enhance the fire
resistance of the batt. Heat is applied at a temperature sufficient
to cure the resin and fuse the fibers to form a batt having a
density and thickness substantially the same as during the heating
step. For products requiring additional loft, compressibility,
resilience and comfort or a light color, a web comprising nonwoven
fibers can be formed. A surface of the nonwoven web is disposed to
a surface of the charring fiber web to form a batt which is
saturated with a resin and heated to cure the resin. Alternatively,
the charring fiber web and the nonwoven web can be separately
saturated with resin, heat cured and then bonded together by
suitable bonding applications. In addition, a relatively thin layer
of a nonwoven fiber which is light in color can be bonded to the
resin bonded batt for aesthetic purposes where loft, compression
and comfort is not required.
[0022] While the resin bonded batt can be high loft, preferably it
is a densified batt having a density of about 1.5 pounds per cubic
foot or greater. Preferably, the batt is relatively thin, having a
thickness in the range of approximately 1/8 inch to approximately 1
inch. The resin bonded densified batt can be used as a fire barrier
layer in a mattress, such as for example, directly below the
ticking, under the quilt backing, under the quilt panels or borders
and above the inner springs. Other suitable applications include as
dust covers in mattresses and furniture. The densified resin bonded
batt is also suitable as a wrap for cushion seats, backs and arms
and for deck padding for furniture and curtain backing material.
Further applications include wraps for hot water tanks and furnaces
and fire and heat shields in building and vehicle walls.
[0023] While heat and resin bonding methods are discuss, other
methods for bonding the fibers of the web to form the batt of the
present invention are suitable, such as, for example, needle
punching, hydro-entangling and mechanical bonding, and are within
in the scope of the present invention.
[0024] The invention is more particularly shown and described in
the accompanying drawings and materials included herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] For a more complete understanding of the present invention,
and for further details and advantages thereof, reference is now
made to the following Detailed Description of the Drawings taken in
conjunction with the accompanying drawings, in which:
[0026] FIG. 1 provides a schematic flow chart of a method according
to an embodiment of the present invention.
[0027] FIG. 2 provides a schematic top plan view of the processing
line for forming a batt according to an embodiment of the method of
the present invention.
[0028] FIG. 3A provides a schematic side view of a thermal bonding
apparatus according to an embodiment of the method of the present
invention.
[0029] FIG. 3B provides a schematic side view of another embodiment
of a thermal bonding apparatus according to the method of the
present invention.
[0030] FIG. 4 provides a perspective top view of an embodiment of a
batt formed from the method of the present invention.
[0031] FIG. 5 provides a perspective top view of another embodiment
of a batt formed from the method of the present invention.
[0032] FIG. 6 provides a schematic flow chart of a method according
to another embodiment of the present invention.
[0033] FIG. 7 provides a perspective top view of further embodiment
of a batt formed from the method of the present invention.
[0034] FIG. 8A is a side cut away view of a traditional
mattress.
[0035] FIG. 8B is a side cut away view of a mattress comprising
embodiments of batts formed from the method of the present
invention.
[0036] FIG. 9 is a side view of a mattress border comprising an
embodiment of a batt formed from the method of the present
invention.
NOTATION AND NOMENCLATURE
[0037] Certain terms are used throughout the following description
and claims to refer to particular components thereof. This document
does not intend to distinguish between components that differ in
name but not in function.
[0038] In the detailed description and the claims that follow, the
terms "including" and "comprising" are used in an open-ended
fashion, and thus should be interpreted to mean "including, but not
limited to . . . ".
[0039] The term "inherent-type FR fibers" generally refers to those
fibers that resist combustion as a result of an essential
characteristic of the fiber.
[0040] The term "non-inherent-type FR fibers" generally refers to
those fibers that are generally considered to be non-FR but have
been treated with a suitable fire retardant chemical to render the
fibers flame resistant.
[0041] The term "charred thermoplastic fibers" generally refers to
FR fibers that carbonize into a charred fiber but will maintain a
stable physical structure when exposed to flame. Both inherent-type
FR fibers and non-inherent-type FR fibers may be charred
thermoplastic fibers.
[0042] The term "FR rayon" generally refers to inherent-type FR
rayon fibers or non-inherent-type FR rayon fibers.
DETAILED DESCRIPTION
[0043] The method for forming a fire combustion modified batt of
the present invention comprises a process for bonding web fibers
together to form a batt. The bonding processes discussed herein
include a thermal bonding process and a resin saturated curing
process. However, other methods may be suitable for bonding web
fibers together to form a fire combustion modified batt and thus
are within the scope of the invention. For example, needle
punching, hydro entangling and mechanical bonds are suitable.
[0044] Turning first to the thermal bonding process which is
representatively and schematically illustrated in FIG. 1, the
method comprises the step of blending nonwoven fibers and charred
thermoplastic fibers, such as oxidized polyacrylonitrile (PAN)
fibers or FR rayon fibers, to form a first web blend. For purposes
of illustrating the process and not by way of limitation, the
charred thermoplastic fibers of the present invention may be
oxidized PAN fibers, such as those marketed under the product name
Pyron.RTM. by Zoltek Corporation. The oxidized polyacrylonitrile
(PAN) fibers are produced from an acrylic precursor. Specifically,
the Pyron.RTM. brand oxidized PAN fiber is a stabilized form of
polyacrylonitrile (PAN) fiber. The stabilization is an oxidation
process that converts the polyacrylonitrile (PAN) fiber from a
thermoplastic state to a thermoset state.
[0045] The discussion herein illustrates generally the method for
forming, and the composition of a particular type of charred
thermoplastic fibers, specifically, oxidized PAN fibers, but is not
a limitation to the scope of the invention. Other methods and
compositions may be suitable for the present invention as would be
understood by one skilled in the art. Generally, several types of
acrylic polymers with variations in their composition have been
used for the production of oxidized PAN fibers. The exact
composition of a particular acrylic precursor varies widely.
Generally, however, the composition contains a minimum of 85%
acrylonitrile and a maximum of 15%, but preferably no more than 8%,
comonomers such as methyl methacrylate, methyl acrylate, vinyl
acetate, vinyl chloride, and other monovinyl compounds.
[0046] In addition to acrylic as a precursor for the production of
carbon fibers, rayon and pitches are also used. The details of the
conversion processes used for different precursors are not the
same, although their essential features are similar. Generally, the
processes involve a stabilizing treatment to prevent melting or
fusion of the fiber, a carbonizing treatment to eliminate the
non-carbon elements and a high temperature graphitizing treatment
to enhance the mechanical properties of the final carbon fiber.
[0047] In the case of PAN fibers, stabilization is carried out by
controlled heating of the precursor fiber in an oxidizing
atmosphere, for example, in air in the temperature range of about
180.degree. C. to 300.degree. C. The heating rate is usually
1-2.degree. C./minute. However, other temperature ranges and
heating rates may be appropriate. Shrinkage can be minimized by
stretching the fibers along their axis during the low-temperature
stabilization treatment Stretching also produces oxidized PAN
fibers with a high degree of preferred orientation along the fiber
axis. The stabilization process produces changes in chemical
structure of the acrylic precursor such that the product becomes
thermally stable to subsequent high temperature treatments. During
this process, the fibers change in color to black. The black fibers
are carbonized in an inert atmosphere at high temperatures, for
example at 1000 to 1500.degree. C. with a slow heating rate to
avoid damage to the molecular order of the fiber. The fibers are
given a graphitizing treatment at high temperatures for example,
above 2000.degree. C. to 3000.degree. C., to improve the texture of
the fiber and to enhance the Young's modulus. The strength and the
modulus of the fibers can also be improved by hot stretching.
[0048] Generally, the physical characteristics of oxidized PAN
fibers are its black color, a moisture content of about 4 to 9
percent, an average fiber diameter of about 11 to 14 microns, a
fiber tensile strength of about 180 to 300 Mpa, a fiber elongation
of about 18 to 28 percent, a fiber density of about 1.36 to 1.38
g/cc and a fiber length of about 4 to 15 cm. In addition, in the
case of Pyron.RTM., the oxidized PAN fibers are thermally stable up
to 600.degree. F. The physical and chemical properties may vary
depending on the specific manufacturing process.
[0049] The nonwoven fibers of the first blend for the present
invention include carrier fibers and binder fibers. The fibers can
be natural or synthetic. For example, thermoplastic polymer fibers
such as polyester are suitable synthetic fibers. Other fibers can
be used depending upon the precise processing limitations imposed
and the characteristics of the batt which are desired at the end of
the process. For purposes of illustrating the process and
combustion modified batt and not by way of limitation, the carrier
fiber is KoSa Type 209, 6 to 15 denier, 2 to 3 inches in length,
round hollow cross section polyester fiber. Alternatively, the
carrier fiber is KoSa Type 295, 6 to 15 denier, 1/5 to 4 inches in
length, pentalobal cross section polyester fiber. Other nonwoven
fibers are suitable as carrier fibers for the present invention and
are within the scope of this invention.
[0050] The binder fiber has a relatively low predetermined melting
temperature as compared with the carrier fiber. As used herein,
however, the term melting does not necessarily refer only to the
actual transformation of the solid polyester binder fibers into
liquid form. Rather, it refers to a gradual transformation of the
fibers or, in the case of a bicomponent sheath/core fiber, the
sheath of the fiber, over a range of temperatures within which the
polyester becomes sufficiently soft and tacky to cling to other
fibers within which it comes in contact, including other binder
fibers having its same characteristics and, as described above,
adjacent polyester fibers having a higher melting temperature. It
is an inherent characteristic of thermoplastic fibers such as
polyester that they become sticky and tacky when melted, as that
term is used herein. For purposes of illustrating the process and
fire combustion modified batt and not by way of limitation, the
binder fiber is KoSa Type 254 Celbond.RTM. which is a bicomponent
fiber with a polyester core and a copolyester sheath. The sheath
component melting temperature is approximately 230.degree. F.
(110.degree. C.). The binder fiber, alternatively, can be a
polyester copolymer rather than a bicomponent fiber.
[0051] While the homogeneous mixture of nonwoven fibers and charred
thermoplastic fibers such as oxidized PAN fibers can be any of a
number of suitable fiber blends, for purposes of illustrating the
process and first blend, the mixture is comprised of binder finders
in an amount sufficient for binding the fibers of the blend
together upon application of heat at the appropriate temperature to
melt the binder fibers. In one example, the binder fibers are in
the range of approximately 5 percent to 50 percent by total volume
of the blend. Preferably, the binder finders are present in the
range of approximately 10 percent to 15 percent for a high loft
batt, and in the range of approximately 15 percent to 40 percent
for a densified batt, as those characteristics are discussed below.
The relative percent volume of charred thermoplastic fibers to
carrier fibers in the remaining blend volume ranges anywhere from
15 percent to 85 percent. In the preferred embodiment, the relative
volume of charred thermoplastic fibers to carrier fibers is about
50 percent to 50 percent. Thus, for example, a blend having 10
percent by volume of binder fibers and a 50 to 50 percent relative
volume of charred thermoplastic fibers to carrier fibers, the
volume of charring PAN fibers and carrier fibers in the blend is 45
percent each. In another example, the volume of charred
thermoplastic fibers and carrier fibers in the blend is 45 percent
each. In a further example, the volume of charred thermoplastic
fibers and carrier fibers having a 50 to 50 percent relative volume
is 40 percent each in a blend having 20 percent by volume of binder
fibers. In a further example, a blend having 20 percent binder
fibers and a 75 percent to 25 percent relative volume mix of
charred thermoplastic fibers to carrier fibers, the volume of
charred thermoplastic fibers and carrier fibers is 60 percent and
20 percent, respectively. Blends having other percentages of
binder, carrier and charred thermoplastic fibers are also within
the scope of the invention.
[0052] Referring back to FIG. 1, the method further comprises an
optional step of blending a homogenous second blend of carrier and
binder fibers to form a second web. The fibers can be the same as
or similar to those of the first web discussed herein, such as, for
example, polyester fibers. Other synthetic or natural fibers can be
used depending upon the precise processing limitations imposed and
the characteristics of the second web which are desired at the end
of the process. While the homogeneous mixture of carrier and binder
fibers can be any of a number of suitable fiber blends, for
purposes of illustrating the process and second blend, the mixture
is comprised of binder finders in the range of approximately 10
percent to 20 percent by volume and carrier fibers in the range of
approximately 90 to 80 percent by volume. Preferably, the binder
finders and carrier fibers are present in the range of
approximately 10 percent to 15 percent and approximately 90 to 85
percent by volume, respectively.
[0053] Referring to FIG. 2, a schematic top plan view of the
general processing line 10 for forming a batt of the present
invention is illustrated. The following example is directed to the
formation of a web in general and thus is applicable to forming
both the first web comprising charred thermoplastic fibers such as
oxidized PAN fibers and nonwoven fibers and the second web of
nonwoven fibers. As discussed above, fibers are blended in a fiber
blender 12 and conveyed by conveyor pipes 14 to a web forming
machine or, in this example, three machines 16, 17, 18. A suitable
web forming apparatus is a garnett machine. An air laying machine,
known in the trade as a Rando webber, or any other suitable
apparatus can also be used to form a web structure. Garnett
machines 16, 17, 18 card the blended fibers into a nonwoven web
having a desired width and deliver the web to cross-lappers 16',
17', 18' to cross-lap the web onto a slat conveyor 20 which is
moving in the machine direction. Cross-lappers 16', 17' 18'
reciprocate back and forth in the cross direction from one side of
conveyor 20 to the other side to form the web having multiple
thicknesses in a progressive overlapping relationship. The number
of layers which make up the web is determined by the speed of the
conveyor 20 in relation to the speed at which successive layers of
the web are layered on top of each other and the number of
cross-lappers 16', 17', 18'. Thus, the number of single layers
which make up the web can be increased by slowing the relative
speed of the conveyor 20 in relation to the speed at which cross
layers are layered, by increasing the number of cross-lappers 16',
17' 18' or both. Conversely, a fewer number of single layers can be
achieved by increasing the relative speed of conveyor 20 to the
speed of laying the cross layers, by decreasing the number of
cross-lappers 16', 17', 18' or both. In the present invention, the
number of single layers which make up the first web of charring and
nonwoven fibers and the second web of nonwoven fibers can be
approximately the same or can vary depending on the desired
characteristics of the fire combustion modified batt of the present
invention. Accordingly, the relative speed of the conveyor 20 to
the speed at which cross layers are layered and the number of
cross-lappers 16', 17', 18' for forming the first web and the
second web may be different.
[0054] Referring back to FIG. 1, the process of the present
invention further comprises disposing a surface of the first web in
a conforming relationship to a surface of the second web to form
the fire combustion modified batt.
[0055] While there are a variety of thermal bonding methods which
are suitable for the present invention, one such method comprises
holding the batt by vacuum pressure applied through perforations of
first and second counter-rotating drums and heating the batt so
that the relatively low melting temperature binder fibers in the
first web and the second web soften or melt to the extent necessary
to fuse the low melt binder fibers together and to the charring and
carrier fibers in the first and second webs. Alternatively, the
batt moves through an oven by substantially parallel perforated or
mesh wire aprons to melt the low temperature binder fibers.
[0056] Referring to FIGS. 2 and 3A, a vacuum pressure method
generally comprises using counter-rotating drums 40, 42 having
perforations 41, 43, respectively, which are positioned in a
central portion of a housing 30. Housing 30 also comprises an air
circulation chamber 32 and a furnace 34 in an upper portion and a
lower portion, respectively, thereof. Drum 40 is positioned
adjacent an inlet 44 though which the batt is fed. The batt is
delivered from the blending and web forming processes described
herein by means of an infeed apron 46. A suction fan 50 is
positioned in communication with the interior of drum 40. The lower
portion of the circumference of drum 40 is shielded by a baffle 51
positioned inside drum 40 so that the suction-creating air flow is
forced to enter drum 40 through perforations 41 which are proximate
the upper portion of drum 40 as it rotates.
[0057] Drum 42 is downstream from drum 40 in housing 30. Drums 40,
42 can be mounted for lateral sliding movement relative to one
another to facilitate adjustment for a wide range of batt
thicknesses (not shown). Drum 42 includes a suction fan 52 which is
positioned in communication with the interior of drum 42. The upper
portion of the circumference of drum 42 is shielded by a baffle 53
positioned inside drum 42 so that the suction-creating air flow is
forced to enter drum 42 through perforations 43 which are proximate
the lower portion of drum 42 as it rotates.
[0058] The batt is held in vacuum pressure as it moves from the
upper portion of rotating drum 40 to the lower portion of counter
rotating drum 42. Furnace 34 heats the air in housing 30 as it
flows from perforations 41, 43 to the interior of drums 40, 42,
respectively, to soften or melt the relatively low melting
temperature binder fibers in the first and second webs to the
extent necessary to fuse the low melt binder fibers together and to
the charring and carrier fibers in the first and second webs.
[0059] REFERRING TO FIG. 3B, in an alternative thermal bonding
process, the batt enters housing 30' by a pair of substantially
parallel perforated or mesh wire aprons 60, 62. Housing 30'
comprises an oven 34' which heats the batt to soften or melt the
relatively low melting temperature binder fibers in the first and
second webs to the extent necessary to fuse the low melt binder
fibers together and to the charring and carrier fibers in the first
and second webs.
[0060] Referring back to FIGS. 2, 3A and 3B, the batt is compressed
and cooled as it exits from housing 30, 30' by a pair of
substantially parallel first and second perforated or wire mesh
aprons 70, 72. Aprons 70, 72 are mounted for parallel movement
relative to each other to facilitate adjustment for a wide range of
batt thicknesses (not shown). The batt can be cooled slowly through
exposure to ambient temperature air or, alternatively, ambient
temperature air can forced through the perforations of one apron,
through the batt and through the perforations of the other apron to
cool the batt and set it in its compressed state. The batt is
maintained in its compressed form upon cooling since the
solidification of the low melt temperature binder fibers in their
compressed state bonds the fibers together in that state.
[0061] Referring to FIGS. 1 and 2, the cooled batt moves into
cutting zone 80 where its lateral edges are trimmed to a finished
width and it is cut transversely to the desired length of batt.
[0062] Referring TO FIGS. 4 and 5, an example of batt 100 and batt
200 formed by the thermal bonding method of the present invention
is illustrated. Batt 100 is comprised of first web 110 having
nonwoven fibers 112 and charred thermoplastic fibers such as
oxidized PAN fibers 114, and second web 120 having nonwoven fibers
122 as discussed previously. Batt 200 is comprised of first web 210
having nonwoven fibers 212 and charred thermoplastic fibers such as
oxidized PAN fibers 214. The weight, density and thickness 102, 202
of batt 100, 200, respectively, are determined by, among other
factors, the process of compressing the batt as it is cooled. The
ratio of batt density to batt thickness 102 generally dictates
whether batt 100 is a high loft batt or a densified bat. For
purposes herein, a densified batt has approximately a 2 to 1 or
greater ratio of weight in ounces per square foot to thickness in
inches. Accordingly, a densified batt has a density of
approximately 1.5 pounds per cubic foot or more. Batts have less
than a 2 to 1 ratio of weight to thickness and less than 1.5 pounds
per cubic foot density are defined herein as high loft bats. For
illustration purposes, batt 100 is a high loft batt while batt 200
is densified. Tables I, II and III provide examples of various
weights and corresponding thicknesses of batts processed by the
thermal bonding method of the present invention.
TABLE-US-00001 TABLE I* Weight Thickness (oz/sq. ft.) (inches)
1/4-1/2 1/2 1/2-3/4 3/4 3/4-1 7/8 1-11/4 11/4 11/4-11/2 11/2
11/2-13/4 13/4 13/4-2 2 2-21/4 21/4 21/4-23/4 23/4 23/4-3 3 3-31/2
31/2 31/2-4 4 *Suitable blends for the weights and thicknesses in
Table I are thermally bonded batts having bicomponent low melt
binder fibers in the amount of approximately 10 percent to 20
percent by total volume of the blend. The remaining blend volume
comprises a relative percent volume of charred thermoplastic fibers
to carrier fibers in the range of approximately 15 percent to 85
percent by relative volume.
TABLE-US-00002 TABLE II* Weight Thickness (oz/sq. ft.) (inches)
3/8-3/4 1/4 3/4-11/2 1/2 11/8-21/4 3/4 13/8-23/8 7/8 11/2-3 1
15/8-33/8 11/8 17/8-33/4 11/4 21/4-41/2 11/2 25/8-51/4 13/4 3-6 2
31/4-63/8 21/8 33/8-63/4 21/4 33/4-71/2 21/2 41/8-81/4 23/4 41/2-9
3 *Suitable blends for the weights and thicknesses in Table II are
thermally bonded batts having bicomponent low melt binder fibers in
the amount of approximately 10 percent to 20 percent by total
volume of the blend. The remaining blend volume comprises a
relative percent volume of charred thermoplastic fibers to carrier
fibers in the range of approximately 15 percent to 85 percent by
relative volume. The batts are compressed to a ratio of weight
(ounces per square foot) to thickness (inches) in the range of
about 1.5 to 1 ratio up to about 3 to 1 ratio.
TABLE-US-00003 TABLE III* Weight Thickness (oz/sq. ft.) (inches)
4-61/4 31/8 41/8-61/2 31/4 43/8-7 31/2 45/8-71/2 33/4 5-8 4
51/8-81/4 41/8 51/4-81/2 41/4 55/8-9 41/2 57/8-91/2 43/4 61/4-10 5
63/8-101/4 51/8 61/2-101/2 51/4 67/8-11 51/2 71/4-111/2 53/4
71/2-101/2 6 75/8-105/8 61/8 77/8-11 61/4 81/8-113/8 61/2
81/2-101/8 63/4 83/4-101/2 7 87/8-102/3 71/8 9-107/8 71/4
93/8-111/4 71/2 95/8-11 1/16 73/4 10-12 8 *Suitable blends for the
weights and thicknesses in Table III are thermally bonded batts
having bicomponent low melt binder fibers in the amount of
approximately 10 percent to 20 percent by total volume of the
blend. The remaining blend volume comprises a relative percent
volume of charred thermoplastic fibers to carrier fibers in the
range of approximately 15 percent to 85 percent by relative volume.
The batts are compressed to a ratio of weight (ounces per square
foot) to thickness (inches) in the range of about 1.25 to 1 ratio
up to about 2 to 1 ratio.
[0063] Referring to FIG. 6, the method for forming the fire
combustion modified batt comprising resin bonding process is
representatively and schematically illustrated. Charred
thermoplastic fibers, such as oxidized PAN fibers or FR rayon
fibers, and carrier fibers are blended to form a first web. Low
melt temperature binder fibers are not required as a heat curable
binder material is used. The charred thermoplastic fibers and
carrier fibers of the blend for the thermal bonding process are
suitable for this application as well. For example, Pyron.RTM. is a
suitable charring fiber, specifically an oxidized PAN fiber, and
thermoplastic fibers such as polyester, and more specifically, KoSa
Type 209 or KoSa Type 295 are suitable carrier fibers. However,
other synthetic and natural fibers can be used depending upon the
precise processing limitations imposed and the characteristics of
the batt which are desired at the end of the process. While the
mixture of charred thermoplastic fibers and carrier fibers in the
first web for the resin bonding method can be any of a number of
suitable fiber blends, for purposes of illustrating the process,
the first blend is comprised of charred thermoplastic fibers, such
as oxidized PAN fibers or FR rayon fibers, in the range of
approximately 15 percent to 100 percent by volume and corresponding
carrier fibers in the range of approximately 85 percent to a
negligible amount.
[0064] Referring back to FIG. 5, the resin bonding method can also
optionally comprise a second blend of carrier nonwoven fibers to
form a second web. The nonwoven fibers can be the same as or
similar to those blended with the charred thermoplastic fibers
discussed above, such as, for example, polyester thermoplastic
polymer fibers. Other synthetic or natural fibers can be used
depending upon the precise processing limitations imposed and the
characteristics of the second web which are desired at the end of
the process.
[0065] The resin bonding method further comprises forming a first
web and a second web, from first and second blends, respectively,
using web forming machines such as garnetts, cross-lappers or air
laying apparatus. The method also comprises the step of disposing a
surface of the first web in a conforming relationship to a surface
of the second web to form the batt. While the second nonwoven web
provides a lighter color to a surface of the batt and may impart
additional loft and comfort, alternatively, a relatively thin layer
of a nonwoven facing material may be suitable for reinforcement to
the first web of charring and carrier fibers. The web and batt
forming steps for the resin bonding method are generally similar to
those for the thermal bonding process which details are discussed
above. An air laying machine can also be used. Generally, the
fibers are introduced into an air stream which carries the fibers
to an air permeable support such as a perforated drum which is
rotating. Accumulation of the fibers onto the drum surface results
in a web formation. A vacuum is applied through the web from one
side of the web to the other and through said air permeable support
sufficient to reduce the thickness and increase the density of the
web throughout the thickness of the web to form a batt.
[0066] Referring back to the schematic of FIG. 6, heat curable
resin is applied to the batt for bonding the web fibers. While
there are a variety of applications, generally resin in the form of
liquid is sprayed while froth resin is extruded onto the batt.
Alternatively, the batt is fed or dipped into a bath of resin.
Resins suitable for the present invention are curable by heat and
can be any of a variety of compositions. Generally, the resin is
comprised of latex or acrylic binders. Additionally, the resin can
comprise fire resistant chemicals which further enhance the fire
resistance of the finished batt.
[0067] In the application of liquid resin, as the batt moves along
a conveyor in the machine direction, the resin is sprayed onto the
batt from one or more spray heads which move in a transverse or
cross direction to substantially coat the batt. Froth resin is
extruded onto the batt using a knife or other means. The batt could
also be fed through or dipped into a resin bath. The applied resin
is crushed into the batt for saturation therethrough by nip rollers
which are disposed along the transverse direction of the conveyor
to apply pressure to the surface of the batt. Alternatively, the
resin is crushed into the batt by vacuum pressure applied through
the batt. The batt moves into an oven heated to a temperature which
cures the resin. The batt exits the oven and is cooled. The batt is
maintained substantially in its oven state upon cooling since the
heat cures the resin which bonds the fibers of the batt together in
this state. The batt moves into a cutting zone where its lateral
edges are trimmed to a finished width and it is cut transversely to
the desired length.
[0068] Referring to FIG. 7, an example of batt 300 formed by the
resin saturated bonding method of the present invention is
illustrated. Batt 300 is comprised of first web 310 having carrier
fibers 312 and charred thermoplastic fibers 314 and a relatively
thin nonwoven layer 320. The weight, density and thickness 302 of
batt 300 are determined by, among other factors, the heating
process which cures the resin and fixes the web in this state. Batt
300 can be high loft or densified depending on the processing
conditions and the desired batt characteristics. As discussed
herein, a densified batt has approximately a 2 to 1 or greater
ratio of weight in ounces per square foot to thickness in inches
which, in terms of density is approximately 1.5 pounds per cubic
foot or more. For illustration purposes, batt 300 is densified.
Table IV provides examples of various weights and corresponding
thicknesses of batts processed by the resin bonding method of the
present invention.
TABLE-US-00004 TABLE IV* Weight Thickness (oz/sq. ft.) (inches)
1/4-3/4 1/8-1/4 3/4-11/2 1/4-1/2 11/2-3 1/2-1 *Suitable blends for
the weights and thicknesses in Table IV are resin bonded batts
having from 15 percent oxidized PAN fibers up to 100 percent and
the remaining volume of polymer carrier fibers.
[0069] Referring to FIGS. 8A and 8B, side views of a traditional
mattress and one which incorporates the thermal and resin bonded
batts of the present invention are provided. In the construction of
a traditional mattress 400, upper structure 420 positioned over the
coil structure 440 includes a quilt panel 422 comprising a cover or
ticking 424, a layer of fiber 426 and a quilt backing 428. Ticking
424, fiber layer 426 and quilt backing 428 are stitched together
and form quilt pattern 423. The quilt panel 422 provides loft,
comfort and resilience to the mattress 400. Upper structure 420 of
the mattress 400 further comprises a layer of foam filling 430
which imparts durability to the mattress 400 as the foam is
relatively stiff as compared to a fiber layer. An insulator 432
separates the foam filling 430 from the coils 440 to minimize the
wear of the foam filling 430 which coils 440 may impart. The lower
structure positioned under the coil structure 440 is a mirror image
of the upper structure 440 and thus is not shown.
[0070] Referring to FIGS. 4, 5, 7 and 8B, mattress 400' which
incorporates the fire combustion modified batts of the present
invention is shown. Quilt panel 422' of upper structure 420' is
comprised of ticking 424, a resin bonded densified batt 300 having
the light colored nonwoven layer 320 proximate the ticking 424, a
thermally bonded high loft batt of charring and nonwoven fibers 110
and a resin bonded densified batt 310 which replaces quilt backing
428. The resin bonded batt 300 provides fire resistant properties
to the mattress near its surface where a flame is likely to contact
while providing a light color for aesthetic purposes. The thermal
bonded high loft fire combustion modified batt 110 provides
sufficient loft, comfort and resilience to effectively replace the
fiber layer 426 of the traditional mattress quilt panel 422 while
imparting additional fire resistance to the mattress. Upper
structure 420' of mattress 400' further comprises a thermally
bonded densified batt 200 which replaces foam filling 430 to impart
durability to mattress 400'. Insulator 432 is replaced with resin
bonded batt 310 to enhance the fire resistant properties of
mattress 400. A second thermally bonded densified batt 200 replaces
the coil structure 440.
[0071] Referring to FIG. 9, a mattress border 500 constructed of a
thermally bonded high loft batt 100 of the present invention is
provided. Border 500 further comprises ticking 502, a foam layer
504 and a quilt backing 506. Batt 100 has a layer 120 of carrier
and binder fibers 122 which is proximate ticking 502 and layer 110
of charred thermoplastic fibers 114 and carrier and binder fibers
112 which is proximate the foam layer 504. Ticking 502, batt 100,
foam layer 504 and quilt backing 506 are stitched together and form
quilt pattern 508. The thermal bonded high loft fire combustion
modified batt 100 provides loft, comfort and resilience to the
border while providing fire resistant properties to the border and
a light color layer 120 of carrier and binder fibers 122 proximate
ticking 502 for aesthetic purposes.
[0072] The thermal and resin bonded batts formed from the methods
of the present invention offer substantial advantages as fire
barrier layers in a wide variety of products, particularly as
mattress components described above. Fire tests conducted on three
mattresses which incorporate various batts of the present invention
were conducted under the State of California Technical Bulletin 129
Flammability Test Procedure for Mattresses for Use in Public
Building, October 1992. A brief description of the test is as
follows. A mattress is placed on a support system. Flames from a
multi hole burner (fueled by propane at the rate of 12 1/min)
impinge on the side of the mattress for a period of 180 seconds.
Test observations are made. The tests were performed on mattresses
comprising the fire combustion modified batts to determine, among
other things, the burning behavior of the mattresses by measuring
the response time which the fire barrier layers would provide to a
fire victim to safely escape and a fire department to successfully
extinguish the fire.
[0073] In a first test, a traditional mattress comprising a quilt
panel of ticking, a polyester fiber layer, a urethane foam layer
and a quilt backing, two layers of foam and an insulator proximate
the coil structure was tested under the California Technical
Bulletin 129. The test ended after 1 minute 27 seconds when unsafe
escalating combustion was noted. In a second test, a thermally
bonded high loft batt replaced the polyester fiber layer beneath
the ticking of a mattress described under the first test. The
thermally bonded high loft batt was comprised of a first layer of
approximately 10 to 15 percent by volume of binder polyester fibers
and the remaining volume was a 50 to 50 percent by volume blend of
Pyron.RTM. oxidized PAN fibers and polyester carrier fibers. The
batt further comprised a second layer of approximately 10 to 15
percent by volume of binder polyester fibers and the remaining
volume was carrier polyester fibers. The weight of each layer was
approximately 0.5 ounce per square inch for a total batt weight of
about 1 ounce per square inch. The second test ended after 18
minutes 40 seconds before unsafe escalating combustion was noted.
Thus, the use of a fire barrier layer in a mattress as described in
the second test effectively increased the time by 17 minutes 13
seconds over the traditional mattress of the first test. This
increase could provide valuable time for a fire victim to escape or
a fire department to extinguish the fire.
[0074] In a third test, a densified resin bonded batt replaced the
insulator proximate the coil structure of the traditional mattress
of the first test. The densified batt was comprised of 50 percent
by volume of oxidized PAN fibers and 50 percent by volume of
polyester fibers and weighed about 3/4 ounces per square foot. The
third test ended after 30 minutes 43 seconds before unsafe
escalating combustion was noted. Thus, the use of a densified batt
formed from the method of the present invention substantially
increases the time over the traditional mattress of the first test
by 29 minutes 16 seconds.
[0075] The thermal and resin bonded batts formed from the methods
of the present invention offer substantial advantages as fire
barrier layers in other products as well. For example, a thermally
bonded fire combustion modified batt having a density of less than
1.5 pounds per cubic foot, a high loft batt, can be used as a wrap
for or an additional layer to cushion seats, backs and arms in
furniture, vehicle and aircraft seats. In seats having a light
colored decorative covering, the batt comprising a layer of
nonwoven fibers would be positioned with the light colored layer
proximate the decorative covering to essentially hide the dark
color oxidized PAN fiber. The thermally bonded high loft batt is
also suitable as an insulation lining in apparel and fire safety
gear such as, for example, in fire fighter jackets and oven mitts
for welding or industrial furnace purposes. Further, the high loft
batt is suitable as a fire barrier air filter and as an insulator
for appliances such as hot water tanks and furnaces. Insulation for
aircraft walls, automobile walls, building walls and recreational
vehicle wall cavities are also suitable applications of the high
loft batt.
[0076] Thermal bonded batts formed from the method of the present
invention having a density of about 1.5 pounds per cubic foot or
greater, densified batts, are suitable as a replacement to cushion
backs, seats and arms in furniture, vehicle and aircraft seats. The
densified batts are also suitable as replacements for mattress
cores, such as, for example, the foam or inner springs in
mattresses, particularly for use in public occupancies and
correctional institutions. Additionally, densified thermally bonded
batts are suitable for insulation lining in apparel and safety gear
such as race driver suits, and as insulation for walls, furnaces
and ducting applications. Densified thermally bonded batts are
particularly suitable for sound deadening and thermal transfer
applications.
[0077] Resin bonded batts, preferably densified batts which are
relatively thin, having a thickness in the range of approximately
1/8 inch to approximately 1/2 inch, have applications as dust
covers in mattresses and furniture. Densified resin bonded batts
are also suitable as wraps for cushion seats, backs and arms and
for deck padding for furniture and curtain backing material.
Further applications include wraps for hot water tanks and furnaces
and fire and heat shields in building and vehicle walls.
[0078] While preferred embodiments have been shown and described,
various modifications and substitutions may be made thereto without
departing from the spirit and scope of the invention. Those skilled
in the art will readily see other embodiments within the scope of
the invention. Accordingly it is to be understood that the method
for forming fire combustion modified batts of the present invention
has been described by way of illustration only and not
limitation.
* * * * *