U.S. patent application number 12/616475 was filed with the patent office on 2010-04-22 for flame-retardant cellulosic nonwoven fabric.
This patent application is currently assigned to POLYMER GROUP, INC.. Invention is credited to Herbert Hartgrove, Gregory Rabon, Russell Tindall.
Application Number | 20100098919 12/616475 |
Document ID | / |
Family ID | 34860354 |
Filed Date | 2010-04-22 |
United States Patent
Application |
20100098919 |
Kind Code |
A1 |
Hartgrove; Herbert ; et
al. |
April 22, 2010 |
FLAME-RETARDANT CELLULOSIC NONWOVEN FABRIC
Abstract
The present invention is directed to a hydroentangled flame
retardant nonwoven fabric, and more specifically, to a cellulosic
flame retardant fabric comprising a self extinguishing fiber so as
to minimize the total percentage of fabric weight lost upon burning
in accordance with technical bulletin 604. Use of natural fiber
fabrics in bedding components is desirable due to the softness and
durability associated with the fabrics; however, natural fiber,
such as cellulose, is highly flammable and therefore lacks the
ability to provide the proper flammability protection often sought
out in bedding components. In accordance with the present
invention, a small amount of self-extinguishing fiber, such as a
modacrylic fiber, was blended with the natural fiber and
hydroentangled to form a nonwoven composite fabric that is soft,
flame retardant, and suitable for bedding articles.
Inventors: |
Hartgrove; Herbert; (Dunn,
NC) ; Rabon; Gregory; (Clayton, NC) ; Tindall;
Russell; (Clemmons, NC) |
Correspondence
Address: |
VALERIE CALLOWAY;CHIEF INTELLECTUAL PROPERTY COUNSEL
POLYMER GROUP, INC., 9335 HARRIS CORNERS PARKWAY SUITE 300
CHARLOTTE
NC
28269
US
|
Assignee: |
POLYMER GROUP, INC.
Charlotte
NC
|
Family ID: |
34860354 |
Appl. No.: |
12/616475 |
Filed: |
November 11, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11053138 |
Feb 8, 2005 |
7638446 |
|
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12616475 |
|
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60542964 |
Feb 9, 2004 |
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Current U.S.
Class: |
428/196 ; 442/1;
442/276; 442/381; 442/394; 442/408 |
Current CPC
Class: |
Y10T 442/10 20150401;
Y10T 442/60 20150401; Y10T 442/689 20150401; Y10S 428/92 20130101;
D04H 1/43 20130101; Y10T 428/2481 20150115; Y10T 442/696 20150401;
Y10T 442/674 20150401; Y10T 442/697 20150401; D04H 1/4382 20130101;
Y10T 442/659 20150401; D04H 1/425 20130101; Y10T 442/698 20150401;
Y10S 428/921 20130101; B32B 2307/308 20130101; B32B 5/022 20130101;
D04H 1/495 20130101; B32B 5/26 20130101; Y10T 442/3772 20150401;
B32B 2307/3065 20130101 |
Class at
Publication: |
428/196 ;
442/408; 442/394; 442/381; 442/276; 442/1 |
International
Class: |
D04H 1/46 20060101
D04H001/46; B32B 27/12 20060101 B32B027/12; B32B 5/26 20060101
B32B005/26; D03D 9/00 20060101 D03D009/00; B32B 3/10 20060101
B32B003/10 |
Claims
1. A flame retardant nonwoven fabric consisting essentially of a
hydroentangled fiber blend consisting essentially of from 60% to
less than 65% lyocell fiber and from more than 35% to 40%
self-extinguishing modacrylic fiber, wherein said fabric exhibits a
basis weight loss of no more than 3% after 360 seconds when tested
in compliance with Technical Bulletin 604 using a bag in bag
construct.
2. (canceled)
3. A flame retardant nonwoven fabric as in claim 1, wherein said
fabric further comprises at least one additional layer selected
from the group consisting of an additional nonwoven, a woven, a
scrim, and a polymer film.
4. A flame retardant bedding article consisting essentially of a
hydroentangled fiber blend consisting essentially of from 60% to
less than 65% lyocell fiber and from more than 35% to 40%
self-extinguishing modacrylic fiber, wherein said fabric exhibits a
basis weight loss of no more than 3% after 360 seconds when tested
in compliance with Technical Bulletin 604 using a bag in bag
construct.
5. A flame retardant nonwoven fabric as in claim 1, wherein said
fabric comprises a three-dimensionally imaged nonwoven fabric.
6. A flame retardant nonwoven fabric consisting essentially of a
hydroentangled fiber blend consisting essentially of 60-65% lyocell
fiber and 40-35% self-extinguishing modacrylic fiber, wherein said
fabric exhibits a basis weight loss of between 0.5%-5% after 360
seconds when tested in compliance with Technical Bulletin 604 using
a sewn in construct.
7. A flame retardant nonwoven fabric as in claim 6, wherein said
fabric exhibits a basis weight loss of between 1%-4% after 360
seconds when tested in compliance with Technical Bulletin 604 using
a sewn in construct.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority of Provisional
Application No. 60/542,964, which was filed on Feb. 9, 2004, and
the disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention generally relates a hydroentangled
flame retardant nonwoven fabric, and more specifically, to a
cellulosic flame retardant fabric comprising a self extinguishing
fiber so as to minimize the total percentage of fabric weight lost
upon burning in accordance with technical bulletin 604.
BACKGROUND OF THE INVENTION
[0003] More than thirty years ago, flammability standards were
instituted by the Consumer Product Safety Commission under 16
C.F.R. .sctn.1632. These standards addressed the flammability
requirements of mattresses to resist ignition upon exposure to
smoldering cigarettes. However, the Code of Federal Regulations
failed to address the need for mattresses to resist ignition upon
exposure to small open flames, such as produced by matches,
lighters, and candles.
[0004] Technological advances have proven to provide mattresses, as
well as bedding constituents, with significantly better
flammability protection. In light of these advancements, California
Legislature has mandated that the Consumer Product Safety
Commission establish a revised set of standards that will ensure
mattresses and bedding pass an open flame ignition test. Known as
Assembly Bill 603 (AB 603), California Legislature has further
mandated that the revised set of standards go into affect Jan. 1,
2004.
[0005] Flame retardant staple fiber is known in the art. Further,
flame retardant fiber has been utilized in the fabrication of
nonwoven fabrics for bedding applications. Nonwoven fabrics are
suitable for use in a wide variety of applications where the
efficiency with which the fabrics can be manufactured provides a
significant economic advantage for these fabrics versus traditional
textiles. However, nonwoven fabrics have commonly been
disadvantaged when fabric properties are compared, particularly in
terms of surface abrasion, pilling and durability in multiple-use
applications. Hydroentangled fabrics have been developed with
improved properties which are a result of the entanglement of the
fibers or filaments in the fabric providing improved fabric
integrity. Subsequent to entanglement, fabric durability can be
further enhanced by the application of binder compositions and/or
by thermal stabilization of the entangled fibrous matrix.
[0006] U.S. Pat. No. 3,485,706, to Evans, hereby incorporated by
reference, discloses processes for effecting hydroentanglement of
nonwoven fabrics. More recently, hydroentanglement techniques have
been developed which impart images or patterns to the entangled
fabric by effecting hydroentanglement on three-dimensional image
transfer devices. Such three-dimensional image transfer devices are
disclosed in U.S. Pat. No. 5,098,764, hereby incorporated by
reference, with the use of such image transfer devices being
desirable for providing a fabric with enhanced physical properties
as well as an aesthetically pleasing appearance.
[0007] Heretofore, nonwoven fabrics have been advantageously
employed for manufacture of flame retardant fabrics, as described
in U.S. Pat. No. 6,489,256, to Kent, et al., which is hereby
incorporated by reference. Typically, nonwoven fabrics employed for
this type of application have been entangled and integrated by
needle-punching, sometimes referred to as needle-felting, which
entails insertion and withdrawal of barbed needles through a
fibrous web structure. While this type of processing acts to
integrate the fibrous structure and lend integrity thereto, the
barbed needles inevitably shear large numbers of the constituent
fibers, and undesirably create perforations in the fibrous
structure. Needle-punching can also be detrimental to the strength
of the resultant fabric, requiring that a fabric have a relatively
high basis weight in order to exhibit sufficient strength.
[0008] A need exists for a more cost effective flame retardant
nonwoven fabric that is cost effective, soft, yet durable and
suitable for various end-use applications including, but not
limited to bedding constituents, such as mattress components,
mattress pads, mattress ticking, comforters, bedspreads, quilts,
coverlets, duvets, pillow covers, as well as other home uses,
protective apparel applications, upholstery, and industrial end-use
applications.
SUMMARY OF THE INVENTION
[0009] The present invention is directed to a hydroentangled flame
retardant nonwoven fabric, and more specifically, to a cellulosic
flame retardant fabric comprising a self extinguishing fiber so as
to minimize the total percentage of fabric weight lost upon burning
in accordance with technical bulletin 604.
[0010] Use of natural fiber fabrics in bedding components is
desirable due to the softness and durability associated with the
fabrics; however, natural fiber, such as cellulose, is highly
flammable and therefore lacks the ability to provide the proper
flammability protection often sought out in bedding components. In
accordance with the present invention, a small amount of
self-extinguishing fiber, such as a modacrylic fiber, was blended
with the natural fiber and hydroentangled to form a nonwoven
composite fabric that is soft, flame retardant, suitable for
bedding articles, and exhibits a minimal amount of mass lost when
tested in compliance with technical bulletin 604, which is a
technical standard for measuring open-flame resistance in filled
bedding articles.
[0011] It has been contemplated that the cellulosic fabric of the
present invention may be a single layer or may comprise additional
layers, wherein the additional layers may be chosen from nonwovens,
wovens, and/or support layers, such as scrims.
[0012] Further, the nonwoven fabric may be hydroentangled on a
foraminous surface, including, but not limited to a
three-dimensional image transfer device, embossed screen,
three-dimensionally surfaced belt, or perforated drum, suitably
further enhancing the aesthetic quality of the fabric for a
particular end-use application.
[0013] Other features and advantages of the present invention will
become readily apparent from the following detailed description,
the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a diagrammatic view of apparatus utilized in
accordance with the present invention so as to manufacture the
flame retardant nonwoven fabric;
[0015] FIG. 2 shows photographs of samples of fabric embodying the
present invention, and comparative samples; and
[0016] FIG. 3 shows data generated in connection with the samples
shown in FIG. 2.
DETAILED DESCRIPTION
[0017] While the present invention is susceptible of embodiment in
various forms, there is shown in the drawings, and will hereinafter
be described, a presently preferred embodiment, with the
understanding that the present disclosure is to be considered as an
exemplification of the invention, and is not intended to limit the
invention to the specific embodiment illustrated.
[0018] The flame retardant nonwoven fabric of the present invention
is cost effective, soft, yet durable and suitable for various
bedding articles including, but not limited to a mattress
component, mattress covers, comforters, bedspreads, quilts,
coverlets, duvets, pillows, pillow covers, in addition to other
home uses, protective apparel applications, and industrial end-use
applications.
[0019] U.S. Pat. No. 3,485,706, to Evans, hereby incorporated by
reference, discloses processes for effecting hydroentanglement of
nonwoven fabrics. With reference to FIG. 1, therein is illustrated
an apparatus for practicing the present method for forming a flame
retardant cellulosic nonwoven fabric. The cellulosic and modacrylic
fibrous components may be carded and optionally cross-lapped to
form a precursor web, designated P, which is consolidated by
hydraulically energy to form a nonwoven fabric.
[0020] Optionally, the precursor web is further entangled on a
foraminous surface, including, but not limited to a
three-dimensional image transfer device, embossed screen,
three-dimensionally surfaced belt, or perforated drum, suitably
further enhancing the aesthetic quality of the fabric for a
particular end-use application.
[0021] It is in the purview of the present invention, that
additional flame retardant fibers be incorporated into the
precursor web, these fibers include, but are not limited to
melamine fibers, phenolic fibers, such as Kynol.TM. fiber from
American Kynol, Inc., pre-oxidized polyacrylonitrile fibers, such
as Panox.RTM. fiber, a registered trademark to R.K. Textiles
Composite Fibres Limited.
[0022] FIG. 1 further illustrates a hydroentangling apparatus,
whereby the apparatus includes a foraminous forming surface in the
form of belt 12 upon which the precursor web P is positioned for
entangling or pre-entangling by manifold 14.
[0023] The entangling apparatus of FIG. 1 may optionally include an
imaging and patterning drum 18 comprising a three-dimensional image
transfer device for effecting imaging and patterning of the lightly
entangled precursor web. The image transfer device includes a
moveable imaging surface which moves relative to a plurality of
entangling manifolds 22 which act in cooperation with
three-dimensional elements defined by the imaging surface of the
image transfer device to effect imaging and patterning of the
fabric being formed.
[0024] It is also contemplated that one or more supplemental layers
be added to the fabric of the present invention, wherein such
layers may include a spunbond fabric. In general, the formation of
continuous filament precursor webs involves the practice of the
"spunbond" process. A spunbond process involves supplying a molten
polymer, which is then extruded under pressure through a large
number of orifices in a plate known as a spinneret or die. The
resulting continuous filaments are quenched and drawn by any of a
number of methods, such as slot draw systems, attenuator guns, or
Godet rolls. The continuous filaments are collected as a loose web
upon a moving foraminous surface, such as a wire mesh conveyor
belt. When more than one spinneret is used in line for the purpose
of forming a multi-layered fabric, the subsequent webs are
collected upon the uppermost surface of the previously formed web.
Further, the addition of a continuous filament fabric may include
those fabrics formed from filaments having a nano-denier, as taught
in U.S. Pat. No. 5,678,379 and No. 6,114,017, both incorporated
herein by reference. Further still, the continuous filament fabric
may be formed from an intermingling of conventional and nano-denier
filaments.
[0025] It has been contemplated that the nonwoven fabric of the
present invention incorporate a meltblown layer. The meltblown
process is a related means to the spunbond process for forming a
layer of a nonwoven fabric is the meltblown process. Again, a
molten polymer is extruded under pressure through orifices in a
spinneret or die. High velocity air impinges upon and entrains the
filaments as they exit the die. The energy of this step is such
that the formed filaments are greatly reduced in diameter and are
fractured so that microfibers of finite length are produced. This
differs from the spunbond process whereby the continuity of the
filaments is preserved. The process to form either a single layer
or a multiple-layer fabric is continuous, that is, the process
steps are uninterrupted from extrusion of the filaments to form the
first layer until the bonded web is wound into a roll. Methods for
producing these types of fabrics are described in U.S. Pat. No.
4,041,203. The meltblown process, as well as the cross-sectional
profile of the meltblown microfiber, is not a critical limitation
to the practice of the present invention.
[0026] In accordance with the present invention, the hydroentangled
flame retardant fabric may comprise a film layer. The formation of
finite thickness films from thermoplastic polymers, suitable as a
strong and durable carrier substrate layer, is a well-known
practice. Thermoplastic polymer films can be formed by either
dispersion of a quantity of molten polymer into a mold having the
dimensions of the desired end product, known as a cast film, or by
continuously forcing the molten polymer through a die, known as an
extruded film. Extruded thermoplastic polymer films can either be
formed such that the film is cooled then wound as a completed
material, or dispensed directly onto a secondary substrate material
to form a composite material having performance of both the
substrate and the film layers.
[0027] Extruded films can be formed in accordance with the
following representative direct extrusion film process. Blending
and dosing storage comprising at least one hopper loader for
thermoplastic polymer chip and, optionally, one for pelletized
additive in thermoplastic carrier resin, feed into variable speed
augers. The variable speed augers transfer predetermined amounts of
polymer chip and additive pellet into a mixing hopper. The mixing
hopper contains a mixing propeller to further the homogeneity of
the mixture. Basic volumetric systems such as that described are a
minimum requirement for accurately blending the additive into the
thermoplastic polymer. The polymer chip and additive pellet blend
feeds into a multi-zone extruder. Upon mixing and extrusion from
the multi-zone extruder, the polymer compound is conveyed via
heated polymer piping through a screen changer, wherein breaker
plates having different screen meshes are employed to retain solid
or semi-molten polymer chips and other macroscopic debris. The
mixed polymer is then fed into a melt pump, and then to a combining
block. The combining block allows for multiple film layers to be
extruded, the film layers being of either the same composition or
fed from different systems as described above. The combining block
is connected to an extrusion die, which is positioned in an
overhead orientation such that molten film extrusion is deposited
at a nip between a nip roll and a cast roll.
[0028] In addition, breathable films can be used in conjunction
with the disclosed continuous filament laminate. Monolithic films,
as taught in U.S. Pat. No. 6,191,211, and microporous films, as
taught in U.S. Pat. No. 6,264,864, both patents herein incorporated
by reference, represent the mechanisms of forming such breathable
films.
[0029] Subsequent to fabric formation, the cellulosic fire
retardant fabric may be subjected to one or more variety of
post-entanglement treatments. Such treatments may include
application of a polymeric binder composition(s), mechanical
compacting, application or incorporation of performance enhancing
additives, electrostatic compositions, and like processes.
[0030] In accordance with the present invention, a representative
sample comprise 60% staple length Tencel.RTM. lyocell fibers,
Tencel.RTM. is a registered trademark of Courtaulds Fibres
(Holdings) Limited, and 40% PBX.RTM. modacrylic fibers, PBX.RTM. is
a registered trademark to Kaneka, with a basis weight of about 2.0
oz/yd.sup.2. Preferably, the nonwoven fabric comprises a 65/35
blend, and more preferably a 70/30 blend, in order to optimize cost
effectiveness, yet still provide the desired performance.
Subsequently, the fiber blend was consolidated into a composite
flame retardant nonwoven fabric by way of hydroentanglement and
tested in accordance with Technical Bulletin 604 to determine the
weight of fabric lost when exposed to open-flames.
[0031] The burn test was conducted utilizing a "sewn in"
construction and a "bag in bag" construction. A "sewn in"
construction is a layered construction, wherein the two layers of
the cellulosic fire retardant fabric is position between two outer
shell layers. The layered construct is sewn along three of the four
sides, fiber-fill is loaded within the inner most cellulosic fire
retardant fabric layers, and the forth side subsequently sewn. A
"bag in bag" construction utilizes a bag made of the cellulosic
fire retardant fabric that is loaded with fiber-fill and sewn
closed. The cellulosic fire retardant fabric bag is then inserted
into a shell bag, wherein the shell bag that encapsulates the
cellulosic fire retardant fabric is sewn closed.
[0032] The fabric of the present invention preferably loses between
0.5%-5% of its basis weight after 360 seconds, and more preferably
between 1%-4%, when tested by a "sewn in" construct (see FIG. 2,
6a). The fabric of the present invention preferably loses between
3%-15% of its basis weight after 360 seconds, and more preferably
between 6%-12%, when tested by a "bag in bag" construct (see FIG.
2, 6b).
[0033] FIG. 3 illustrates the physical test results of the
aforementioned fabric, as well as test results for comparative
samples illustrated in FIG. 2.
[0034] From the foregoing, it will be observed that numerous
modifications and variations can be affected without departing from
the true spirit and scope of the novel concept of the present
invention. It is to be understood that no limitation with respect
to the specific embodiments illustrated herein is intended or
should be inferred. The disclosure is intended to cover, by the
appended claims, all such modifications as fall within the scope of
the claims.
* * * * *