U.S. patent application number 10/078170 was filed with the patent office on 2003-08-21 for non-pilling insulating flame-resistant fabrics.
Invention is credited to Green, James R..
Application Number | 20030157294 10/078170 |
Document ID | / |
Family ID | 27732789 |
Filed Date | 2003-08-21 |
United States Patent
Application |
20030157294 |
Kind Code |
A1 |
Green, James R. |
August 21, 2003 |
Non-pilling insulating flame-resistant fabrics
Abstract
Insulating flame-resistant woven fabrics have been discovered
which have a non-pilling pile on the back side of the fabric to
provide an insulating layer of stagnant air and have long wear
life.
Inventors: |
Green, James R.; (Bonita
Springs, FL) |
Correspondence
Address: |
Terry M. Gernstein
1015 Salt Meadoow Lane
McLean
VA
22101
US
|
Family ID: |
27732789 |
Appl. No.: |
10/078170 |
Filed: |
February 20, 2002 |
Current U.S.
Class: |
428/91 ; 442/136;
442/141; 442/209; 442/214; 442/215 |
Current CPC
Class: |
D06C 11/00 20130101;
Y10T 428/2395 20150401; Y10T 442/3228 20150401; Y10T 442/2631
20150401; D03D 27/00 20130101; Y10T 442/3276 20150401; Y10T
442/2672 20150401; Y10T 442/3268 20150401 |
Class at
Publication: |
428/91 ; 442/209;
442/214; 442/215; 442/136; 442/141 |
International
Class: |
D03D 027/00; D06C
011/00 |
Claims
1. An insulating durable flame-resistant fabric comprising:
3.times.1 and 4.times.1 construction; at least 1% phosphorus; a
non-pilling pile on a fill-face side; warp yarns; fill yarns; said
warp yarns containing 15 to 30% nylon fibers and 70 to 85% cotton
fibers; said fill yarns being 100% cotton; said fill yarns having a
fill yarn tear strength of no less than 3 lbs.
2. The insulating fabric defined in claim 1 having a fill tear
strength of no less than 5 lbs.
3. The insulating fabric defined in claim 1 in which the nylon
fibers are T-420 fibers from Dupont.
4. The insulating fabric defined in claim 1 which contains at least
2% of phosphorus by weight of fabric as part of a ammonia cured
flame-retardant.
5. The insulating fabric defined in claim 1 which contains at least
1% of phosphorus by weight of fabric as part of a heat cured
flame-retardant.
6. The insulating fabric defined in claim 1 which includes twill
construction
7. The insulating fabric defined in claim 1 which includes sateen
construction.
Description
TECHNICAL FIELD
[0001] The present invention relates to the general field of
fabrics, and to the particular area of flame-resistant fabrics.
BACKGROUND
[0002] It is well known in the prior art that woven fabrics can be
finished by abrading one or both surfaces to obtain a soft surface
texture resembling a suede leather or prewashed fabric as is
explained in U.S. Pat. Nos. 4,918,795, 4,863,775, 4,837,902 and the
teachings are entirely incorporated herein by reference. The sueded
or washed feeling in the fabric is created by raising the fibers of
the constituent material while at the same time nicking or
splitting some of the raised ends to soften the filaments. Another
patent, U.S. Pat. No. 5,468,545 teaches that flame-retardant
treated fabrics can be made durable by blending small amounts of
thermoplastic fibers with cotton. Efficient ways of flame-retarding
fabrics made from blends of cotton and thermoplastic fibers with
tetrakis (hydroxymethyl) phosphonium compounds (THP) are described
in U.S. Pat. Nos. 4,909,805 and 5,480,458. While improvement in
hand and thermal protection can be achieved, sanding enhances the
formation of small balls as fiber ends freed by sanding pull loose
and entangle when garments are worn or washed. When synthetic
fibers are incorporated in fabrics to increase wear life, these
strong fibers hold the cotton balls on the sanded surface producing
an unsightly appearance and reducing the effectiveness of the
insulating layer. A number of methods for reducing pilling are well
known which involve weakening the synthetic fibers with or without
temporarily immobilizing them as explained in U.S. Pat. No.
5,468,545 and the teachings are incorporated entirely herein by
reference. Knit fabrics have long been used to make pile fabrics
because some knit structures lend themselves to forming loops,
which can be cut without loosing fabric integrity. Knits are not
the subject of this disclosure.
SUMMARY OF THE INVENTION
[0003] This invention provides cotton/thermoplastic fiber blend
flame-resistant fabrics with an insulating pile on the backside
that is non-pilling. It has been discovered that woven 3.times.1
and 4.times.1 twill and sateen fabrics that contain 15-30% nylon in
the warp and 100% cotton on the fill side can be sanded on the fill
side without inducing pilling and without a significant reduction
in wear life provided that the final sanded fabrics have a tear
strength of no less than 3 lbs when fabrics are torn across along
the warp direction to break the yarns.
[0004] Woven fabrics of this invention have a 3.times.1 or
4.times.1 twill or sateen construction and have an insulating pile
on the back made up primarily of sanded fill yarns, 15-30% nylon in
the warp yarns, 100% cotton yarns in the fill direction, a fill
tear strength of at least 3 lbs and contain at least 1.0%
phosphorus by weight of the fabric due to flame-retardant contained
therein.
DETAILED DESCRIPTION OF THE INVENTION
[0005] This invention adds enhanced thermal protection to long wear
life flame-resistant woven fabrics by sanding the backside of
3.times.1 or 4.times.1 twill or sateen cotton blend fabrics which
contain a very narrow range of nylon in the warp and by limiting
the strength loss due to sanding such that the tears along the warp
direction which break the fill yarns require at least 3 lbs to
propagate.
[0006] The staple fibers used herein are textile fibers having a
linear density suitable for wearing apparel, i.e., less than 10
decitex per fiber, preferably less than 5 decitex per fiber. Still
more preferred are fibers having a linear density of 1 to 3 decitex
per fiber and length from 1.9 to 6.3 cm (0.75 to 2.5 in). Crimped
fibers are particularly good for textile aesthetics and
processibility.
[0007] It is important to use nylon in the warp because it has the
best fatigue life of all of the commercially available
thermoplastic fibers and is capable of maintaining the integrity of
the warp much better than other fibers, such as polyester, when the
garment is abraded by normal wash and wear conditions. The warp
yarn pinches the fill yarns at crossover points and slows down the
rate at which the broken ends in the sanded fill yarns come free
and the fabric breaks. With less than 15% nylon in the yarns,
normal wash and wear fatigue will quickly loosen the grip of the
warp yarns and subsequently the fill yarns weakened by sanding will
break prematurely and the warp yarns will follow so that holes are
formed. With more than 30% nylon in the warp, the fabrics lose a
significant part of their flame-resistance. The fill must be 100%
flame-retardant treated cotton because sanding nylon blend yarns
will cause pilling and the fabric will burn once the nylon fibers
are raised and have increased access to oxygen.
[0008] Fill yarns must cross over at least 3 or 4 warp yarns in
order to shield the cotton/nylon warp yarns from the sander when
the fabric is rubbed on the backside. Twills and sateen of
3.times.1 or 4.times.1 construction are suitable for this purpose
whereas plain weave or fabrics of 2.times.1 construction are not.
Fabrics of a style which allows too much exposure of the warp yarns
on the backside will lose warp tensile and tear strength upon
sanding and styles wherein the yarn crossover points of warp and
fill are too far apart will weaken and have poor wear life after
sanding as the broken fibers will fall out.
[0009] While sanding will not cause fabrics of the invention to
pill during washing or wearing or cause significant warp damage, it
will cause strength loss in the fill direction. In order to keep
normal garment stress from tearing the garment, the fill strength
must not be reduced below 3 lbs during the sanding operation.
Sanding can occur at any stage in the production of the fabric,
greige, after flame-retarding treatment or after the fabric has
been compressively shrunk, such as by Sanforization.
[0010] Fabrics must be flame-retardant treated in order to meet the
objective of the invention which is to provide fabrics with
flame-resistance and enhanced thermal insulation.
[0011] At least two satisfactory commercial products are available.
One is Pyroset TPO, a THPS/urea precondensate of tetrakis
(hydroxymethyl) phosphonium sulfate and Urea available from Freedom
Chemical Company, Charlotte, N.C. The other is THPC/urea prepolymer
condensate of tetrakis (hydroxymethyl) phosphonium chloride and
urea sold by Albright and Wilson. While these compounds are ammonia
cured, other phosphorus flame-retardant chemicals may also be used
which involve heat treatment for curing.
Measurements
[0012] Tear strength of fabrics was measured using the American
Society for Testing Materials (ASTM) test D1424, Elmendorf tear.
Tensile strength was measured using ASTM-D5035-95, strip tensile.
Fabric pieces were folded and sewn together at cut edges with the
fill face on the inside of the fabric to simulate a sewn garment.
Sewn pieces were washed 75 times and examined for pilling on the
inside. Pilling was determined by empirical analysis and rated as
non-pilling, moderate, substantial. Holes or significant fiber loss
from abrasion were used to determine wear life.
EXAMPLE 1
[0013] Woven fabric was made as a 3.times.1 twill having in the
warp 25% of polyhexamethylene adipamide (6,6 nylon) fibers and 75%
cotton. The fill was 100% cotton. The fabric was prepared, dyed and
flame-retardant treated such that it contained 2.5% phosphorus. The
fabric was compressively shrunk to loosen the structure. It was
then sanded on the fill side using a conventional multi-roll sander
with fine grit sandpaper. A noticeable pile was generated on the
backside of the fabric. Fill tear strength was reduced from 7 to 5
lbs. Warp tear and tensile strength was reduced less than 15%. Sewn
fabric pieces washed and dried 75 times showed no signs of pilling
and wear.
EXAMPLE 2
[0014] The same woven fabric described in Example 1 was sanded
after flame-retardant treatment to create an insulative pile. Fill
strength was reduced from 7 to 4 lbs. Warp tear and tensile
strength was reduced less than 15%. The fabric was compressively
shrunk to reduce shrinkage. Fabrics washed and dried 75 times
showed no signs of pilling or wear. Comparative Example A not of
this invention was made by sanding such that fill strength was
reduced to 2 lbs. Warp tear and tensile strength was reduced less
than 15%. Sewn fabric pieces washed and dried 75 times had
holes.
EXAMPLE 3
[0015] Woven fabric was made as a 4.times.1 sateen having in the
warp 25% of polyhexamethylene adipamide (6,6 nylon) fibers and 75%
cotton. The fill was 100% cotton. The fabric was prepared, dyed and
flame-retardant treated such that it contained more than 2%
phosphorus. It was compressively shrunk. It was then sanded on the
fill side using a conventional multi-roll sander with fine grit
sandpaper. Fill tear strength was reduced to 4 lbs. Warp tear and
tensile strength was reduced less than 15%. Sewn pieces washed and
dried 75 times showed no signs of pilling and had minimal wear.
Comparative Example B not of this invention was made by sanding a
100% flame-resistant cotton fabric of similar construction to
reduce fill strength to 4 lbs. After 75 washes the sewn piece had
holes.
[0016] It is understood that while certain forms of the present
invention have been illustrated and described herein, it is not to
be limited to the specific forms or arrangements of parts described
and shown.
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