U.S. patent application number 13/517069 was filed with the patent office on 2012-10-18 for polyethylene terephthalate fiber for air-bags and textiles made from same.
This patent application is currently assigned to Hyosung Corporation. Invention is credited to IL-Won Jung, Seung-Cheol Yang, Je-An Yu.
Application Number | 20120263401 13/517069 |
Document ID | / |
Family ID | 44196261 |
Filed Date | 2012-10-18 |
United States Patent
Application |
20120263401 |
Kind Code |
A1 |
Jung; IL-Won ; et
al. |
October 18, 2012 |
POLYETHYLENE TEREPHTHALATE FIBER FOR AIR-BAGS AND TEXTILES MADE
FROM SAME
Abstract
A polyethylene terephthalate multifilament prepared by spinning
polyethylene terephthalate chips having an intrinsic viscosity of
0.8 to 1.3 is provided. In order to improve the energy absorption
capability of a textile for polyethylene terephthalate air bags, a
textile for air bag having an improved rupture property at a welt
portion in an air bag cushion deployment test can be prepared using
a polyethylene terephthalate fiber by adjusting a
strength/deformation curve of the polyethylene terephthalate fiber.
Here, the polyethylene terephthalate fiber has a
strength/deformation curve in which the polyethylene terephthalate
fiber extends by less than 4% when subjected to an initial stress
of 1.0 g/d at room temperature, extends by less than 12% subjected
to a medium stress of 4.5 g/d and extends by 3% or more until
fibers are cut at a tensile strength of at least 7.0 g/d, and has
an elongation at break of 15% or more, a carboxyl end group (CEG)
content of 35 mmol/kg or less, and a single fiber thickness of 5
deniers or less.
Inventors: |
Jung; IL-Won; (Bucheon-si,
KR) ; Yang; Seung-Cheol; (Anyang-si, KR) ; Yu;
Je-An; (Yangcheon-gu, KR) |
Assignee: |
Hyosung Corporation
Seoul
KR
|
Family ID: |
44196261 |
Appl. No.: |
13/517069 |
Filed: |
December 14, 2010 |
PCT Filed: |
December 14, 2010 |
PCT NO: |
PCT/KR2010/008942 |
371 Date: |
June 19, 2012 |
Current U.S.
Class: |
383/117 ;
57/1R |
Current CPC
Class: |
D03D 15/00 20130101;
B60R 2021/23504 20130101; D06M 15/693 20130101; D01F 6/62 20130101;
D01D 5/12 20130101; D03D 1/02 20130101; D06M 15/564 20130101; D10B
2331/04 20130101; D06M 15/263 20130101; D10B 2505/124 20130101;
D06M 15/643 20130101 |
Class at
Publication: |
383/117 ;
57/1.R |
International
Class: |
B65D 30/04 20060101
B65D030/04; D01H 1/16 20060101 D01H001/16 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 24, 2009 |
KR |
10-2009-0130817 |
Dec 29, 2009 |
KR |
10-2009-0132770 |
Claims
1. A polyethylene terephthalate multifilament for air bags made by
spinning polyethylene terephthalate chips having an intrinsic
viscosity (IV) of 0.8 to 1.3, wherein the polyethylene
terephthalate multifilament has a strength/deformation curve in
which the polyethylene terephthalate multifilament extends by less
than 4% when subjected to an initial stress of 1.0 g/d at room
temperature, extends by less than 12% when subjected to a medium
stress of 4.5 g/d and extends by 3% or more until fibers are cut at
a tensile strength of at least 7.0 g/d, and has an elongation at
break of 15% or more and a single fiber thickness of 5 deniers or
less.
2. The polyethylene terephthalate multifilament for air bags
according to claim 1, wherein the polyethylene terephthalate
multifilament has a value of 1.5 or more, in case which is
calculated by dividing an F/F coefficient of kinetic friction of a
yarn by an F/M coefficient of kinetic friction of the yarn.
3. The polyethylene terephthalate multifilament for air bags
according to claim 1, wherein the polyethylene terephthalate
multifilament has a carboxyl end group (CEG) content of 35 mmol/kg
or less.
4. The polyethylene terephthalate multifilament for air bags
according to claim 1, wherein the polyethylene terephthalate
multifilament has a maximum thermal stress of 0.2 to 0.5 g/d.
5. The polyethylene terephthalate multifilament for air bags
according to claim 1, wherein the polyethylene terephthalate
multifilament has a total fiber thickness of 150 to 1,000
deniers.
6. A textile for air bags woven from the polyethylene terephthalate
multifilament defined in claim 1.
7. A coated textile for air bags which is prepared by coating the
textile for air bags defined in claim 6 with a coating agent
selected from the group consisting of a silicon-based coating
agent, a polyurethane-based coating agent, an acrylic coating
agent, a neoprene-based coating agent and a chloroprene-based
coating agent at a content of 15 to 60 g/m.sup.2, and has the
following physical properties: (1) Tensile strength: 190 to 300
kgf, (2) Tear strength: 25 to 40 kgf, and (3) Air permeability: 0.5
cubic feet per minute (CFM) or less.
Description
TECHNICAL FIELD
[0001] The present invention relates to a polyethylene
terephthalate fiber for air bags and a textile for air bags made
from the same, and, more particularly, to a textile for air bags
having an improved rupture property at a sewn welt portion so that
a polyethylene terephthalate multifilament made by spinning
polyethylene terephthalate chips having an intrinsic viscosity of
0.8 to 1.3 can be prevented from rupturing in an air bag cushion
deployment test when the polyethylene terephthalate multifilament
is applied to the textile for air bags by adjusting a
strength/deformation curve of the polyethylene terephthalate
multifilament.
BACKGROUND ART
[0002] A textile for air bags requires a variety of characteristics
such as low poromericity to smoothly deploy an air bag upon
collision, high energy absorption capability to prevent
damage/breakage of an air bag itself, and foldability for a textile
itself to improve storage. A Nylon 66 material has been widely used
as a fiber that is suitable for the requirements of such an air bag
textile. In recent years, increasing attention has been paid to
fiber materials rather than Nylon 66 due to their economic
efficiency, for example, cost savings, etc.
[0003] In order to apply a polyethylene terephthalate yarn to an
air bag, an air bag rupturing problem should be solved in an air
bag cushion module deployment test. For this purpose, attempts have
been made to improve the energy absorption capability of a
polyethylene terephthalate air bag and prevent an air bag from
rupturing at a sewn welt portion of the air bag as the air bag
expands.
DISCLOSURE
Technical Problem
[0004] The present invention is directed to providing a textile for
air bags made from a polyethylene terephthalate fiber having an
improved rupture property at a sewn welt portion so that a
polyethylene terephthalate multifilament can be prevented from
rupturing in an air bag cushion deployment test by adjusting a
strength/deformation curve of the polyethylene terephthalate
multifilament.
Technical Solution
[0005] One aspect of the present invention provides a polyethylene
terephthalate multifilament for air bags made by spinning
polyethylene terephthalate chips having an intrinsic viscosity of
0.8 to 1.3. Here, the polyethylene terephthalate multifilament for
air bags is characterized in that it has a strength/deformation
curve in which the polyethylene terephthalate multifilament extends
by less than 4% when subjected to an initial stress of 1.0 g/d at
room temperature, extends by less than 12% when subjected to a
medium stress of 4.5 g/d and extends by 3% or more until fibers are
cut at a tensile strength of at least 7.0 g/d, and has an
elongation at break of 15% or more and a single fiber thickness of
5 deniers or less.
[0006] According to one exemplary embodiment of the present
invention, the polyethylene terephthalate multifilament has a value
of 1.5 or more, in case which is calculated by dividing an F/F
coefficient of kinetic friction of a yarn by an F/M coefficient of
kinetic friction of the yarn.
[0007] According to another exemplary embodiment of the present
invention, the polyethylene terephthalate multifilament has a
carboxyl end group (CEG) content of 35 mmol/kg or less.
[0008] According to still another exemplary embodiment of the
present invention, the polyethylene terephthalate multifilament has
a maximum thermal stress of 0.2 to 0.5 g/d.
[0009] According to still another exemplary embodiment of the
present invention, the polyethylene terephthalate multifilament has
a total fiber thickness of 150 to 1,000 deniers.
[0010] Another aspect of the present invention provides a textile
for air bags which is woven from the polyethylene terephthalate
multifilament. Here, the textile for air bags is prepared by
coating the textile for air bags with one coating agent selected
from the group consisting of a silicon-based coating agent, a
polyurethane-based coating agent, an acrylic coating agent, a
neoprene-based coating agent and a chloroprene-based coating agent
at a content of 15 to 60 g/m.sup.2.
Advantageous Effects
[0011] According to the present invention, a textile for air bags
having an improved rupture property at a welt portion in an air bag
cushion deployment test can be prepared using a polyethylene
terephthalate fiber that can be prepared from the polyethylene
terephthalate multifilament. Here, the polyethylene terephthalate
multifilament has a strength/deformation curve in which the
polyethylene terephthalate fiber extends by less than 4% when
subjected to an initial stress of 1.0 g/d at room temperature,
extends by less than 12% subjected to a medium stress of 4.5 g/d
and extends by 3% or more until fibers are cut at a tensile
strength of at least 7.0 g/d, and has an elongation at break of 15%
or more, a value of 1.5 or more, in case which is obtained by
dividing an F/F coefficient of kinetic friction of a yarn by an F/M
coefficient of kinetic friction of the yarn, a carboxyl end group
(CEG) content of 35 mmol/kg or less, and a single fiber thickness
of 5 deniers or less.
Mode for Invention
[0012] Hereinafter, exemplary embodiments of the present invention
will be described in detail. However, the present invention is not
limited to the embodiments disclosed below, but can be implemented
in various forms. The following embodiments are described in order
to enable those of ordinary skill in the art to embody and practice
the present invention.
[0013] Although the terms first, second, etc. may be used to
describe various elements, these elements are not limited by these
terms. These terms are only used to distinguish one element from
another. For example, a first element could be termed a second
element, and, similarly, a second element could be termed a first
element, without departing from the scope of exemplary embodiments.
The term "and/or" includes any and all combinations of one or more
of the associated listed items.
[0014] It will be understood that when an element is referred to as
being "connected" or "coupled" to another element, it can be
directly connected or coupled to the other element or intervening
elements may be present. In contrast, when an element is referred
to as being "directly connected" or "directly coupled" to another
element, there are no intervening elements present.
[0015] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
exemplary embodiments. The singular forms "a," "an" and "the" are
intended to include the plural forms as well, unless the context
clearly indicates otherwise. It will be further understood that the
terms "comprises," "comprising," "includes" and/or "including,"
when used herein, specify the presence of stated features,
integers, steps, operations, elements, components and/or groups
thereof, but do not preclude the presence or addition of one or
more other features, integers, steps, operations, elements,
components and/or groups thereof.
[0016] The present invention is directed to providing a textile for
air bags having an improved rupture property at a sewn welt portion
so that a polyethylene terephthalate multifilament made by spinning
polyethylene terephthalate chips having an intrinsic viscosity of
0.8 to 1.3 can be prevented from rupturing in an air bag cushion
deployment test when the polyethylene terephthalate multifilament
is applied to the textile for air bags by adjusting a
strength/deformation curve of the polyethylene terephthalate
multifilament.
[0017] In order for a textile for air bags to safely absorb
instantaneous impact energy of an exhaust gas generated by
explosion of gunpowder in an air bag, a polyethylene terephthalate
multifilament obtained by spinning polyethylene terephthalate chips
having an intrinsic viscosity (IV) of 0.8 to 1.3 is used in the
present invention. A polyester yarn in which a resin has an
intrinsic viscosity of less than 0.8 dl/g is not desirable since
the polyester yarn does not have sufficient toughness.
[0018] In addition to polyethylene terephthalate, a resin used to
form a multifilament for air bags according to the present
invention may include polybutylene terephthalate, polyethylene
terephthalate, polybutylene naphthalate,
polyethylene-1,2-bis(phenoxy)ethane-4,4'-dicarboxylate,
poly(1,4-cyclohexylene-dimethylene terephthalate) and a copolymer
including the polymer as one or more repeating unit. Specific
examples of the resin may be selected from the group consisting of
polyethylene terephthalate/isophthalate copolyester, polybutylene
terephthalate/naphthalate copolyester, polybutylene
terephthalate/decanedicarboxylate copolyester, and a mixture of at
least two of the polymers and copolymers. Among theses, a
polyethylene terephthalate resin is particularly preferably used in
the present invention due to its mechanical properties and fiber
formation characteristics.
[0019] The polyethylene terephthalate fiber according to the
present invention may have a carboxyl end group (CEG) content of 35
mmol/kg or less. When the CEG content of the polyethylene
terephthalate yarn exceeds 35 mmol/kg, hydrolysis resistance of a
yarn may be degraded, and thus it is difficult to maintain
performance of a textile for air bags under high temperature and
humidity conditions.
[0020] A fiber suitable for use as the polyethylene terephthalate
multifilament for air bags according to the present invention may
extend by less than 4% when the fiber is subjected to an initial
stress of 1.0 g/d in a strength/deformation curve. When the
polyethylene terephthalate multifilament extends by 4% or more at
an initial stress of 1.0 g/d, a textile may be suddenly deformed
and damaged at the beginning.
[0021] Also, when a filament is subjected to a medium stress of 4.5
g/d, the filament may extend by less than 12%. When the filament
extends by 12% or more at a medium stress of 4.5 g/d, a human body
may get burned by an exhaust gas due to a sudden increase in
poromeric degree of the textile.
[0022] In addition, the textile made from the polyethylene
terephthalate multifilament may extend by 3% or more until fibers
are cut at a tensile strength of at least 7.0 g/d, so as to allow
the textile to have a tensile strength and a tear strength which
are suitable for use as an air bag. This is problematic because,
when the textile extends by less than 3% until the fibers are cut
at a tensile strength of at least 7.0 g/d, a maximum capability of
the fibers to absorb a tensile load is insufficient. As a result,
when the fibers are woven from the textile having a low weight, the
tensile strength and tear strength of the fibers may not be
sufficient.
[0023] According to the present invention, the polyethylene
terephthalate multifilament for air bags may have an elongation at
break of 15% or more. When the elongation at break of the
multifilament is less than 15%, an energy absorption capability
when an air bag cushion suddenly expands may be degraded, and thus
the cushion may burst.
[0024] According to the present invention, the polyethylene
terephthalate multifilament for air bags may have a maximum thermal
stress of 0.2 to 0.6 g/d. A yarn may have an insufficient strength
under conditions for production of yarn having a maximum thermal
stress of less than 0.2 g/d, whereas the yarn may have a low
elongation under conditions for production of yarn having a maximum
thermal stress greater than 0.6 g/d. As a result, the air bag
cushion may easily burst in the air bag cushion deployment
test.
[0025] According to the present invention, the polyethylene
terephthalate multifilament for air bags may preferably have a
total fiber thickness of 150 to 1,000 deniers, more preferably 200
to 700 deniers. When the yarn having a total fiber thickness of
less than 150 deniers is used, the textile for air bags may be
insufficient in storage, but an air bag may be broken as a
passenger collides against the air bag during or after deployment
of the air bag. In contrast, when the total fiber thickness exceeds
1,000 deniers, the safety of the air bag may be satisfied due to
sufficient strength thereof, but the storage of the air bag may be
reduced due to an increase in thickness of the textile.
[0026] The multifilament constituting the textile for air bags may
preferably have a single fiber thickness of 5 deniers or less, more
preferably 4.5 deniers or less. In general, when fibers having a
low single fiber thickness are used, the resulting textile is
flexible, and thus has excellent foldability and good storage.
Also, a covering property may be improved as the single fiber
thickness decreases. As a result, it is possible to control the
poromericity of the textile. When the single fiber thickness
exceeds 5 deniers, the foldability and storage of the textile may
be reduced, and the low poromericity may also be degraded.
Therefore, the textile may not sufficiently function as the textile
for air bags.
[0027] According to the present invention, a ratio of an F/F
friction coefficient means a value obtained by dividing a
coefficient of kinetic friction (F/F .mu.s) between fibers of a
polyethylene terephthalate yarn by a coefficient of kinetic
friction (F/M .mu.s) between fibers and metal. The ratio of the F/F
friction coefficient is preferably 1.5 or more. More preferably, a
yarn whose ratio of the F/F friction coefficient is 2.0 or more may
be suitably used for the textile for air bags. When the ratio of
the F/F friction coefficient is less than 1.5, a friction
coefficient between the fibers is insufficient, and thus a sewn
welt portion may increasingly rupture in the air bag cushion
deployment test.
[0028] In order to sufficiently increase the ratio of the F/F
friction coefficient to 1.5 or more and secure good spinning
workability, it is important to select a proper spinning emulsion.
Either an emulsion type or a solvent type may be used as a type of
a spinning emulsion. However, it is desirable to use an emulsion
having a relatively higher F/F friction coefficient than an F/M
friction coefficient.
[0029] According to one exemplary embodiment of the present
invention, a polyethylene terephthalate yarn for air bags may be
prepared by spinning a spinning emulsion, which is selected from
the emulsion types of spinning emulsions, at an OPU attachment
content of 0.6%.
[0030] The polyethylene terephthalate fiber prepared by the
preparation method according to the present invention may be
obtained using an air jet or water jet loom weaving machine.
However, since a residual oil in the textile has to be present at a
content of 0.1% by weight or less, the polyethylene terephthalate
fiber may be prepared using the water jet loom weaving machine in
consideration of the detachability of an emulsion attached to
fibers. Also, the woven fiber may be subjected to a refining
process and thermal setting at 160 to 190.degree. C.
[0031] When a textile is woven from the polyethylene terephthalate
fiber prepared by the preparation method according to the present
invention, it is desirable to weave a plain fabric having a
symmetrical structure. In order to selectively obtain an attractive
textile, a filament having a lower linear density may be woven from
a 2/2 Panama woven fabric having a symmetrical structure.
[0032] The woven textile may be coated with a coating agent
selected from the group consisting of a silicon-based coating
agent, a polyurethane-based coating agent, an acrylic coating
agent, a neoprene-based coating agent and a chloroprene-based
coating agent at a content of 15 to 60 g/m.sup.2, and used to
secure the low poromericity that is suitable for use in the textile
for air bags.
[0033] According to the present invention, physical properties of
polyethylene terephthalate yarns of Examples and Comparative
Examples were measured and evaluated, as follows.
[0034] 1) Intrinsic Viscosity (I.V.)
[0035] 0.1 g of a test sample is dissolved for 90 minutes in a
reagent (90.degree. C.) obtained by mixing phenol with
1,1,2,2-tetrachloroethanol at a weight ratio of 6:4. Thereafter,
the resulting sample solution is transferred to an Ubbelohde
viscometer, and kept at 30.degree. C. for 10 minutes in a
thermostat. Then, a dipping time (second) of the sample solution is
calculated using a viscometer and an aspirator. Also, a dipping
time (second) of the solvent is obtained in the same manner as
described above. Then, an R.V. value and an I.V. value are
calculated using the following equations.
R.V.=dipping time (second) of test sample/dipping time (second) of
solvent
I.V.=1/4.times.[(R.V.-1)/C]+3/4.times.(In R.V./C)
[0036] In the equations, C represents a concentration (g/100 ml) of
the test sample in the sample solution.
[0037] 2) Measurement of Thermal Stress of Yarn
[0038] A yarn is prepared into a loop having a diameter of 10 cm
using a thermal stress tester (Model name: KE-3LS commercially
available from KANEBO), and hung on upper/lower end hooks. Then, an
initial load of 0.05 g/den is applied to the test sample, and the
test sample is heated at a rate of 2.2.degree. C./second. In this
case, stress caused in the test sample is measured and plotted as a
graph.
[0039] 3) Measurement of CEG Content of Yarn
[0040] A CEG content is analyzed using a test method "GG7"
((Geosynthetic Research Institute (GRI)), and indicated by units of
mmol/kg.
[0041] 4) Measurement of Tenacity Elongation of Yarn
[0042] A yarn is kept for 24 hours in a constant
temperature/humidity chamber which is maintained under standard
conditions, that is, a temperature of 25.degree. C. and 65%
relative humidity, and the test samples is then measured according
to ASTM 2256 method using a tensile tester.
[0043] 5) Friction Fastness of Yarn
[0044] A coefficient of kinetic friction (F/F .mu.s) between fibers
is measured while rubbing yarns at a rate of 3 cm/min using a
friction tester (Model name: YF-850 commercially available from
TORAY). Also, a coefficient of kinetic friction (F/M .mu.s) between
fibers and a metal is measured while rubbing a Ni-coated metal with
a yarn at a rate of 200 m/min. Then, a ratio of an F/F friction
coefficient is calculated by dividing an F/F .mu.s value by an F/M
.mu.s value.
[0045] 6) Tensile Strength of Textile
[0046] Instron 4465 (commercially available from Instron, US) is
kept for 24 hours under standard conditions (20.degree. C. and 65%
relative humidity) according to the ASTM D 5034 standard method.
Then, a tensile strength of a textile having a width of 10 cm and a
length of 15 cm is measured.
[0047] 7) Tear Strength of Textile
[0048] Instron 4465 (commercially available from Instron, US) is
kept for 24 hours under standard conditions (20.degree. C. and 65%
relative humidity) according to the ASTM D 2261 standard method.
Then, a tear strength of a textile is measured.
[0049] 8) Air Permeability of Textile
[0050] The air permeability of a textile is measured at a pressure
of 125 Pa according to the ASDM 737 standard method using a Frazier
air permeability tester.
[0051] 9) Air Bag Cushion Deployment Test
[0052] A module is manufactured from a woven fabric for air bags
and kept at 85.degree. C. for 4 hours. Thereafter, a deployment
test is performed on the module within 3 minutes to determine
whether or not the module ruptures, and an evaluation of "PASS" or
"FAIL" is made.
[0053] Hereinafter, the present invention will be described in
detail with reference to the following Examples. However, it should
be understood that these Examples are not intended to limit or
define the scope of the present invention.
EXAMPLE 1
[0054] A grey fabric for air bags was prepared from a polyethylene
terephthalate yarn having characteristics listed in Table 1, using
a water jet loom weaving machine, so that the plain fabric could
have 50.times.50 textiles per inch. In this case, a spinning
emulsion used herein was an emulsion (Trade name: TNX-021) having a
relatively high F/F friction coefficient selected from
emulsion-type spinning emulsions (commercially available from
Takemoto) and spun at an OPU attachment content of 0.6%.
COMPARATIVE EXAMPLE 1
[0055] A grey fabric for air bags was prepared from a polyethylene
terephthalate yarn having characteristics listed in Table 1 in the
same manner as in Example 1.
[0056] In this case, a spinning emulsion used herein was an
emulsion (Trade name: TN-0071T) having a relatively high F/F
friction coefficient selected from emulsion-type spinning emulsions
(commercially available from Croda-WooBang Cc., Ltd.) and spun at
an OPU attachment content of 0.6%.
TABLE-US-00001 TABLE 1 Single fiber Ratio of F/F Elongation
Elongation Elongation CEG thickness Strength Elongation friction
(%) at (%) at at break (%) content Norm (den) (g/den) (%)
coefficient 1.0 g/d 4.5 g/d at 7.0 g/d (mmol/kg) Example 1 500 4.2
9.0 22.6 3.16 0.9 9.7 5.1 25.4 d/l 20f Comparative 500 4.1 9.1 20.3
1.43 0.9 9.8 5.3 25.2 Example 1 d/l 20f
EXAMPLE 2
[0057] The grey fabric prepared in Example 1 was passed through a
water bath at 95.degree. C. so that the grey fabric was refined and
thermally contracted. Thereafter, the grey fabric was thermally
fixed at 185.degree. C. for 2 minutes. Then, a textile for air bags
was prepared by coating the grey fabric with a silicon-based
coating agent at a content of 25 g/m.sup.2. The physical properties
of the textile prepared thus were evaluated and an air bag cushion
deployment test was also performed on the textile. The results are
listed in the following Table 2.
COMPARATIVE EXAMPLE 2
[0058] A textile for air bags was prepared by treating the grey
fabric prepared in Comparative Example 1 in the same manner as in
Example 2. Then, the physical properties of the textile were
evaluated and an air bag cushion deployment test was also performed
on the textile. The results are listed in the following Table
2.
TABLE-US-00002 TABLE 2 Tensile Tear strength Air bag strength (warp
(warp Air cushion yarn .times. weft yarn .times. weft permeability
deployment yarn, kgf) yarn, kgf) (CFM) test Example 2 223 .times.
221 27.3 .times. 27.7 0.1 or less PASS Comparative 219 .times. 215
27.0 .times. 28.6 0.1 or less FAIL Example 2
EXAMPLE 3
[0059] A grey fabric for air bags was prepared from a polyethylene
terephthalate yarn, which was prepared through a spinning process
under the conditions: a GR4 temperature of 250.degree. C., a GR5
temperature of 170.degree. C. and a relax ratio of 9.2% to have
characteristics listed in Table 3, using a water jet loom weaving
machine, so that the plain fabric could have 50.times.50 textiles
per inch.
COMPARATIVE EXAMPLE 3
[0060] A grey fabric for air bags was prepared in the same manner
as Example 3 from a polyethylene terephthalate yarn which was
prepared in the same conditions as Example 3 except for the
conditions: a GR4 temperature of 175.degree. C., a GR5 temperature
of 100.degree. C. and a relax ratio of 1.9% in a spinning process,
to have characteristics listed in Table 3
TABLE-US-00003 TABLE 3 Single fiber CEG Maximum Elongation
Elongation Elongation thickness Strength Elongation content thermal
stress (%) at (%) at at break (%) Norm (den) (g/den) (%) (mmol/kg)
(g/den 1.0 g/d 4.5 g/d at 7.0 g/d Example 3 500 4.2 9.0 22.6 25.1
0.29 0.9 9.7 5.1 d/l 20f Comparative 630 13.2 8.1 12.3 25.3 0.53
0.8 5.4 4.0 Example 3 d/48f
EXAMPLE 4
[0061] The grey fabric prepared in Example 3 was passed through a
water bath at 95.degree. C. so that the grey fabric was refined and
thermally contracted. Thereafter, the grey fabric was thermally
fixed at 185.degree. C. for 2 minutes. Then, the grey fabric was
coated with a silicon-based coating agent at a content of 25
g/m.sup.2.
[0062] The physical properties of the textile prepared thus were
evaluated and an air bag cushion deployment test was also performed
on the textile. The results are listed in the following Table
4.
COMPARATIVE EXAMPLE 4
[0063] A textile for air bags was prepared by treating the grey
fabric prepared in Comparative Example 3 in the same manner as in
Example 4. Then, the physical properties of the textile were
evaluated and an air bag cushion deployment test was also performed
on the textile. The results are listed in the following Table
4.
TABLE-US-00004 TABLE 4 Tensile Tear strength Air bag strength (warp
(warp Air cushion yarn .times. weft yarn .times. weft permeability
deployment yarn, kgf) yarn, kgf) (CFM) test Example 4 223 .times.
221 27.3 .times. 27.7 0.1 or less PASS Comparative 241 .times. 239
27.9 .times. 28.8 0.1 or less FAIL Example 4
[0064] While the invention has been shown and described with
reference to certain exemplary embodiments thereof, it will be
understood by those skilled in the art that various changes in form
and details may be made therein without departing from the scope of
the invention as defined by the appended claims.
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