U.S. patent application number 12/528488 was filed with the patent office on 2010-03-18 for thermoplastic fiber with excellent durability and fabric comprising the same.
Invention is credited to Hyeun Cho, Dong-Eun Lee, Joon-Young Yoon.
Application Number | 20100068516 12/528488 |
Document ID | / |
Family ID | 39721421 |
Filed Date | 2010-03-18 |
United States Patent
Application |
20100068516 |
Kind Code |
A1 |
Yoon; Joon-Young ; et
al. |
March 18, 2010 |
THERMOPLASTIC FIBER WITH EXCELLENT DURABILITY AND FABRIC COMPRISING
THE SAME
Abstract
Disclosed are a thermoplastic fiber with excellent durability
and a fabric comprising the same. More particularly, the
thermoplastic fiber contains fluoropolymer particles with average
particle diameter ranging from 0.01 to 5.0/.LAMBDA.II in
thermoplastic resin to form the fiber. The inventive thermoplastic
fiber is prepared by adding the fluoropolymer particles to the
thermoplastic resin while spinning the thermoplastic resin. The
inventive thermoplastic fiber exhibits superior durability, that
is, resistance to friction and/or modification and is preferably
adopted as yarns for footwear, furniture, (mountain-climbing)
backpacks, abrasives, sportswear and so on.
Inventors: |
Yoon; Joon-Young;
(Geongsangbuk-Do, KR) ; Lee; Dong-Eun; (
Geongsangbuk-Do, KR) ; Cho; Hyeun; (Bunsan,
KR) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
39721421 |
Appl. No.: |
12/528488 |
Filed: |
February 26, 2008 |
PCT Filed: |
February 26, 2008 |
PCT NO: |
PCT/KR08/01098 |
371 Date: |
August 25, 2009 |
Current U.S.
Class: |
428/372 |
Current CPC
Class: |
D01F 6/92 20130101; Y10T
428/2927 20150115; D01F 1/10 20130101 |
Class at
Publication: |
428/372 |
International
Class: |
D02G 3/22 20060101
D02G003/22 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 26, 2007 |
KR |
10-2007-0018863 |
Feb 27, 2007 |
KR |
10-2007-0019308 |
Feb 27, 2007 |
KR |
10-2007-0019309 |
Claims
1. A thermoplastic fiber with excellent durability comprising
thermoplastic resin, in which fluoropolymer particles having
average particle diameter in the range from 0.01 to 5.0 .mu.m are
contained in the thermoplastic resin.
2. The thermoplastic fiber according to claim 1, wherein the fiber
has monofilament fineness of not more than 20 denier.
3. The thermoplastic fiber according to claim 1, wherein content of
the fluoropolymer ranges from 0.1 to 9.0% by weight.
4. The thermoplastic fiber according to claim 1, wherein the
fluoropolymer particles have average particle diameter ranging from
0.1 to 1.0 .mu.m.
5. The thermoplastic fiber according to claim 1, wherein the
fluoropolymer comprises at least one selected from a group
consisting of polytetrafluoroethylene polymer, copolymer of
tetrafluoroethylene and hexafluoropropene, copolymer of
tetrafluoroethylene and perfluoroalkylvinylether, and terpolymer
thereof.
6. The thermoplastic fiber according to claim 1, wherein the
thermoplastic fiber is a sea-island type composite fiber that
contains island components with monofilament fineness ranging from
0.001 to 0.3 denier dispersed in sea components formed of alkali
releasing and eluting polymer.
7. The thermoplastic fiber according to claim 6, wherein the island
components contain fluoropolymer particles with average particle
diameter ranging from 0.01 to 5.0 .mu.m.
8. The thermoplastic fiber according to claim 1, wherein the
thermoplastic fiber is a thermoplastic hollow fiber having hollow
portions in cross-sectional area thereof.
9. The thermoplastic fiber according to claim 1, wherein the
thermoplastic hollow fiber has a hollow rate ranging from 10 to
40%.
10. A fabric comprising the thermoplastic fiber defined in claim 1.
Description
TECHNICAL FIELD
[0001] The present invention relates to a thermoplastic fiber with
excellent durability and a fabric comprising the same, and more
particularly, to a thermoplastic fiber with excellent durability in
response to friction and/or modification, which includes
fluoropolymer particles with average particle diameter ranging from
0.01 to 5.0 .mu.m in thermoplastic resin to form the fiber, as well
as a fabric comprising the thermoplastic fiber.
BACKGROUND ART
[0002] In order to improve durability of a thermoplastic fiber made
of polyamide and/or polyethylene terephthalate, the following
methods well known in prior art are principally used.
[0003] The first method is to enhance mechanical properties of a
yarn itself by increasing molecular weight of a base resin for the
thermoplastic fiber during the polymerization process.
[0004] The second method is to increase a basic thickness of a
thermoplastic fiber bundle during the spinning process of yarns.
That is, as overall fiber fineness is increased, a load level
applied to unit area is decreased. It is generally known that a
fiber with 10 denier is stronger than that with 1 denier and a
fiber with 1.00 denier is stronger than that with 10 denier.
[0005] The third method is to increase strength of a yarn through
multiple-staged drawing and heat treatment by treating the yarn to
have high orientation and/or crystallization while spin-drawing the
yarn under a specific condition satisfying at least one or two of
the above two conditions by altering conditions for drawing
yarns.
[0006] The increase of molecular weight of the basic resin to form
the thermoplastic fiber during the polymerization process, is
accomplished by methods generally classified into two kinds of
method. One of the methods is an extension of polymerization time
period because molecular weight of a polymer is increased as the
time is extended. However, this originally has limits in view of
processing time and efficiency. For polyethylene terephthalate, a
rate of increasing initial molecular weight has a linear
correlation to time, but the increase of molecular weight depending
on time tends to be considerably slowed with intrinsic viscosity in
a range of more than 0.6. That is, there is a problem in that the
molecular weight is rarely increased due to time required for the
polymerization. Moreover, the molecular weight tends to be reduced
due to side reactions, after reaching a peak of the intrinsic
viscosity at a constant level.
[0007] In order to overcome the above problems, polyethylene
terephthalate is polymerized with the intrinsic viscosity ranging
from 0.5 to 0.7, passed through a solid state polymerization dryer
which can uniformly apply high temperature of more than 150.degree.
C. to the polymer, thereby improving crystallization of the
polymer. This commonly called "solid state polymerization" and
usually increases intrinsic viscosity of polymer to a level ranging
from 1.0 to 1.3. Such method causes significant time loss and
productivity, and also incurs a heavy loss in view of production
cost. Especially, in a case that time and hot air blowing are
undesirably controlled during the solid state polymerization, there
will be additional problems, for example, such that polyester
portions may be agglomerated and adhered together while polyamide
materials may cause change of colors such as yellowing.
Accordingly, the solid state polymerization has difficulties in
being adopted for general applications except special uses.
[0008] The other method is to ensure desirable durability and
friction resistance ability of a yarn while increasing overall
fineness thereof during the spinning process, which exhibits a
disadvantage of limited increasing of fineness dependent on uses of
the method. For example, a garment fabric formed using the yarn
preferably has a standard weight ranging from 50 to 300 g/m.sup.2.
If the standard weight is below the lower limit, the yarn is too
soft to perform weaving and/or knitting thereof. In contrast, for
the standard weight of above the upper limit, a garment formed
using the garment fabric is so heavy that a consumer hardly wears
the garment, and is restricted in common daily life activity. In
particular, when the fineness is increased, there is a reduction of
soft feeling and flexibility of the fabric itself leading to
stiffness of the fabric. Consequently, the fiber has limited
fineness depending on uses thereof.
[0009] Furthermore, it is known that a method for increasing
strength of a yarn by alteration of drawing conditions includes
multi-staged drawing processes, for example, two-staged,
three-staged or four staged process dependant upon purposes of use
thereof, widely employed rather than a single drawing process. The
multi-staged drawing process allows increase of strength in return
for elongation reducing rate of the yarn according to multiple
steps of the drawing process. Further heat treatment is effectively
practiced together with the drawing process.
[0010] However, the multi-staged heat treatment process has
expected limitations. More particularly, after producing a
preformed yarn, the produced yarn is sometimes kept without any
additional process for a constant period of time, then, is
subjected to re-drawing by a multi-staged drawing device.
Otherwise, the yarn is produced by a multi-stepped spinning
immediate drawing device. However, the above heat treatment needs a
great dimension of apparatus, exhibits reduced final drawing and
winding rate in contrast to initial spinning speed and lower
productivity, and has difficulties in processing to possibly cause
lowered yield. Therefore, this process is not recommended in view
of productivity.
[0011] The above conditions for improvement of durability are basic
conditions for reducing weight of fibers or fabrics. But, many
cases require premise conditions commercially available for
reduction of the weight. If appropriate durability is ensured,
weight reduction effect can be embodied by a thin fabric with lower
fineness and, additionally, weight of the fabric is reduced while
maintaining the same apparent form of the fabric.
[0012] Most of the cases are involved in the latter, such that the
apparent form should be continuously unchanged, although the weight
is reduced. These cases cannot often accept decrease of fabric
density and thickness caused by using microfine yarns.
[0013] Under these circumstances, the most preferable fabrics
comprise hollow fibers, and apparent specific gravity of a yarn is
lowered to less than 1.0, that is, the constant specific gravity of
water. Particularly, a polyamide fabric must accomplish a weight
reduction rate of more than about 15% by weight while polyester
fabric needs a weight reduction rate of more than about 25% by
weight, in order to reduce the apparent specific gravity below 1.0
and, in turn, achieve the weight reduction. Herein, the internal
hollow rate is determined by measuring a ratio of total area of
hollow portions in cross-sectional area of the fiber relative to
overall cross-sectional area of the fiber.
[0014] For the hollow fiber, the internal hollow rate is one of
conditions for the weight reduction. Although apparent weight
reduction is accomplished by increasing the internal hollow rate,
strength and elongation of the yarn itself are substantially
decreased. The hollow fiber generates markedly higher spinning
draft by 5 to 10 times than that of typical yarns having circular
cross-sectional areas according to conventional processes, leading
to reduction of both of strength and elongation of the yarn itself.
Accordingly, even though the yarn satisfies the conditions for
polymerization, spinning and drawing processes, durability of the
hollow fiber is rapidly decreased. When comparing durability of the
above hollow fiber with that of a fiber having the same fineness or
reduced weight, the durability of the hollow fiber is also
considerably lowered. This is because a severe modification was
caused by effective reduction of cross-sectional area and a
substantially excessive drawing process.
[0015] Meanwhile, sea-island type composite fibers (often referred
to as "sea-island fiber") are complicated yarns commonly prepared
using thermoplastic resin as island components and alkali
release-elution type resin as sea components, which are mostly used
in manufacturing ultra-fine yarns that comprise only island
components of the sea-island fibers on a fabric by eluting the
island components during processing after production of the fabric,
and preparing microfine yarns from the sea-island fibers.
[0016] Such sea-island fibers generally used to prepare artificial
leather or suede fabrics, become ultra-fine yarns with monofilament
fineness ranging from 0.0001 to 0.3 denier. Polyester yarns
comprising the ultra-fine yarns have diameter ranging from 0.1
.mu.m to 3 .mu.m. Due to ultra fineness, a fabric manufactured has
inherent properties such as very soft touch feel and lightening
effect (that is, weight reduction effect), so as to establish a
territory of important synthetic fabric fields.
[0017] However, frictional durability of an ultra-fine yarn is
significantly poor due to ultra fineness even though strength and
durability per unit fineness are excellent, as converted into 1
denier of ultra-fine yarn bundle. Conventional artificial leathers
or suede fabrics manufactured using the ultra-fine yarn have been
restricted to uses for garments, however, use of these fabrics
continues to expand into non-textile products such as furniture and
bedding, and/or industrial applications such as for abrasives,
wiping cloths, etc.
[0018] These trends require improvement of mechanical properties
together with inherent properties of suede fabric. In other words,
in order to expand use of the fabric into non-textile products or
industrial applications, durability of the fabric often called
frictional fastness/abrasion resistance must be enhanced. At
present, the frictional fastness is not favorable and stands on a
level in the range from grade 1 to grade 2.
DISCLOSURE OF THE INVENTION
Technical Problem
[0019] Accordingly, the present invention is directed to solve the
problems described above in regard to difficulties in improving
durability of yarns and an object of the present invention is to
provide a novel thermoplastic fiber with excellent durability and
fabrics comprising the same.
[0020] Another object of the present invention is to provide a
thermoplastic hollow fiber with light weight as well as excellent
durability and a fabric comprising the same.
[0021] Another object of the present invention is to improve
durability, especially, frictional fastness and abrasion resistance
of an ultra-fine yarn comprising only island components of a
sea-island type composite fiber by eluting sea components of the
sea-island fiber.
[0022] A still further object of the present invention is to
improve durability of a sea-island fiber sufficient to be used as a
yarn for furniture, bedding, abrasive materials, etc. as well as a
yarn for garments.
Technical Means to Solve the Problem
[0023] Hereinafter, the present invention is described in
detail.
[0024] A thermoplastic fiber of the present invention which
comprises thermoplastic resin, contains fluoropolymer particles
with average particle diameter ranging from 0.01 to 5.0 .mu.m in
the thermoplastic resin.
[0025] The fluoropolymer includes at least one selected from a
group consisting of polytetrafluoroethylene polymer, copolymer of
tetrafluoroethylene and hexafluoropropene, copolymer of
tetrafluoroethylene and perfluoroalkylvinylether, and terpolymer
thereof.
[0026] Examples of perfluoroalkylvinylether
perfluoropropylvinylether, perfluoroethylvinylether and the
like.
[0027] The fluoropolymer particles are contained in the
thermoplastic resin to form the thermoplastic fiber, so as to
reduce friction coefficient of the fiber.
[0028] Briefly, the fluoropolymer particles in the thermoplastic
resin reduce metal friction coefficient of a yarn and, in turn,
protect the thermoplastic fiber itself when the particles are
placed on surface of the fiber.
[0029] Content of the fluoropolymer particles preferably ranges
from 0.1 to 9.0% by weight.
[0030] With the content of less than 0.1% by weight, it is
difficult to ensure desired abrasion resistance and durability of
the fiber. On the other hand, if the content exceeds 9.0% by
weight, the fiber exhibits preferable abrasion resistance and
durability over the desired level. However, the fiber also has
excess tensile strength and frictional properties over desired
levels suitable to manufacture yarns, thus, may cause significant
trouble and/or very poor processing during spinning including, for
example: extreme vibrations of a yarn guide; collapse of a yarn
guide independent of yarn winding angles on a winding drum,
etc.
[0031] The fluoropolymer particles have average particle diameter
ranging from 0.01 to 5.0 .mu.m, more preferably, from 0.1 to as
determined by a microscope or an electron microscope. With less
than 0.01 .mu.m, there are difficulties in overcoming agglomeration
of particles due to breaking fluoropolymer into particles and
microfine diameter thereof. In contrast, when the particle diameter
exceeds 5.0 .mu.m, the particles as a mineral material show no
continuity and serve as the weakest point during the spinning in
production of fibers using the thermoplastic resin, therefore, may
become a direct cause of yarn cutting or reduction of processing
ability.
[0032] The thermoplastic fiber according to the present invention
may comprise common yarns composed of thermoplastic resin,
sea-island type composite fibers in which island components with
monofilament fineness ranging from 0.01 to 0.3 denier are dispersed
in sea components composed of alkali releasing and eluting polymer,
thermoplastic hollow fiber having hollow portions in
cross-sectional area of the fiber, and so on.
[0033] When the thermoplastic fiber is the sea-island fiber,
fluoropolymer particles having average particle diameter ranging
from 0.01 to 5.0 .mu.m are contained in island components of the
fiber.
[0034] A hollow rate of the thermoplastic hollow fiber preferably
ranges from 10 to 40% dependent on types of the thermoplastic
resin. With a hollow rate of less than 10%, there is substantially
little effect of weight reduction. If the hollow rate is more than
40%, even well formed hollows may be easily collapsed by external
force.
[0035] The present invention further provides a fabric comprising
the thermoplastic fiber which contains fluoro polymer particles
with average particle diameter ranging from 0.01 to 5.0 .mu.m in
thermoplastic resin. Content of the thermoplastic fiber preferably
ranges from 40 to 100% by weight.
ADVANTAGEOUS EFFECTS
[0036] The fabrics manufactured by the present invention exhibit
excellent durability and lightness, that is, weight reduction
effect.
[0037] For example, in case of a polyester carpet requiring a
constant abrasion resistance number of 2,000 times under ASTM-D3884
conditions, carpets manufactured using conventional polyester yarns
with 150 denier rarely have an abrasion resistance of more than
1,400 times although texture of the carpet and conditions for a
dyeing process are advantageously altered.
[0038] However, the thermoplastic fiber (common fiber) according to
the present invention can produce a carpet with a specific abrasion
resistance number of more than 2,000 times even by using the fiber
with 150 denier.
[0039] In addition, a material in 75 denier grade originally having
an abrasion resistance number of about 350 times can increase the
abrasion resistance number to more than 500 times, and further
enhance abrasion resistance after a false twisting process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The above objects, features and advantages of the present
invention will become more apparent to those skilled in the related
art in conjunction with the accompanying drawings. In the
drawings:
[0041] FIG. 1 and FIG. 2 are illustrative cross sectional views of
thermoplastic hollow fibers according to the present invention,
respectively.
DESCRIPTION OF SYMBOLS FOR MAJOR PARTS IN DRAWINGS
[0042] 1: hollow fiber [0043] A: thermoplastic resin [0044] B:
hollow portion
BEST MODE FOR CARRYING OUT THE INVENTION
[0045] Hereinafter, the present invention will be described in
detail from the following examples and comparative examples with
reference to the accompanying drawings. However, these are intended
to illustrate the invention as preferred embodiments of the present
invention and do not limit the scope of the present invention.
Example 1
[0046] Using polyethylene terephthalate as a base polymer, a master
batch containing 15% by weight of polytetrafluoroethylene
particles, which have average particle diameter of 0.5 .mu.m as
measured by an electron microscope, was prepared.
[0047] With the prepared master batch and the base polymer of
polyethylene terephthalate, a polyethylene terephthalate fiber
comprising 36 filaments with 75 denier was produced by a spinning
and direct drawing process. Content of polytetrafluoroethylene
particles in the fiber was controlled to 1% by weight by regulating
content of the master batch.
[0048] 88 strands of the fibers were produced in a drum with 4 kg
capacity, woven by means of an interlock circular knitting machine
with 22 gauge, and dried at a rate of 30 m/min using a hot air
dryer after dyeing at 130.degree. C. for 60 minutes to produce a
circular knitted fabric.
[0049] A result of measuring an abrasion resistance number of the
produced fabric is shown in Table 1.
Example 2
[0050] A polyethylene terephthalate fiber and a circular knitted
fabric comprising the same were prepared by the same procedure as
in Example 1, except that average particle diameter of the above
polytetrafluoroethylene particles was altered to 1.0 .mu.m and
content of the particles in the polyethylene terephthalate fiber
was altered to 2%.
[0051] A result of measuring an abrasion resistance number of the
produced fabric is shown in Table 1.
Example 3
[0052] A circular knitted fabric was produced under the same
conditions described in Example 1 by using a false twisted yarn
based on polyethylene terephthalate, which was prepared by false
twisting a polyethylene terephthalate fiber (containing 1% by
weight of polytetrafluoroethylene in the fiber) obtained under the
same conditions described in Example 1.
[0053] A result of measuring an abrasion resistance number of the
produced fabric is shown in Table 1.
Example 4
[0054] A circular knitted fabric was produced under the same
conditions described in Example 2 by using a false twisted yarn
based on polyethylene terephthalate, which was prepared by false
twisting polyethylene terephthalate fibers (containing 2% by weight
of polytetrafluoroethylene in the fiber) obtained under the same
conditions described in Example 2.
[0055] A result of measuring an abrasion resistance number of the
produced fabric is shown in Table 1.
Example 5
[0056] Using polyethylene terephthalate as a base polymer for
island components of a fiber, a master batch containing 15% by
weight of polytetrafluoroethylene particles, which have average
particle diameter of 2.0 .mu.m as measured by an electron
microscope, was prepared.
[0057] With the prepared master batch, a 36 split type sea-island
composite fiber comprising 24 filaments with 75 denier was produced
by a spinning and direct drawing process. Content of the island
components in the fiber were about 70% by weight while sea
components of the fiber based on alkali releasing and eluting
polymer were added in an amount of about 30% by weight. Content of
polytetrafluoroethylene particles in the island components was
controlled to 1% by weight by regulating content of the master
batch.
[0058] 88 strands of the sea-island fibers were prepared in a drum
with 4 kg capacity, false twisted and combined with a highly
shrinkable yarn comprising 12 filaments with 30 denier, which
represents shrinkage of 25% when immersed into hot water at
100.degree. C. for 30 minutes, so as to produce a yarn comprising
36 filaments with 105 denier. After weaving the yarn by means of an
interlock circular knitting machine with 32 gauge, the woven fabric
underwent a shrinkage process using a raising machine and a
shearing process to obtain a base fabric. Subsequently, a strong
alkaline NaOH solution with 50% purity was added to the base fabric
in hot water at 100.degree. C. to control overall concentration of
a weight reducing solution to 1% by weight. Herein, a ratio by
weight of total amount of the solution to weight of the fabric is
controlled to 40:1. Using the solution, the weight of the fabric
was reduced by about 24% by weight relative to total weight of the
fabric over a period of 60 minutes, followed by scouring and
washing processes. The treated fabric was subjected to a dyeing
process at 130.degree. C. for 60 minutes and a drying process using
a hot air dryer at 180.degree. C. and a rate of 30 m/min. After
brushing, a circular knitted fabric was obtained as the final
product.
[0059] A result of measuring an abrasion resistance number of the
produced fabric is shown in Table 1.
Example 6
[0060] Using polyethylene terephthalate as a base polymer, a master
batch containing 15% by weight of polytetrafluoroethylene
particles, which have average particle diameter of 0.5 as measured
by an electron microscope, was prepared.
[0061] With the prepared master batch, a polyethylene terephthalate
hollow fiber comprising 48 filaments with 150 denier was produced
by a spinning and direct drawing process. Content of
polytetrafluoroethylene particles in the hollow fiber was
controlled to 1% by weight by regulating content of the master
batch. The hollow fiber had a hollow rate of about 30%.
[0062] 88 strands of the fibers were produced in a drum with 4 kg
capacity, woven by means of an interlock circular knitting machine
with 22 gauge, and dried at a rate of 30 m/min using a hot air
dryer after dyeing at 130.degree. C. for 60 minutes to complete a
circular knitted fabric.
[0063] A result of measuring an abrasion resistance number of the
produced fabric is shown in Table 1.
Example 7
[0064] Using polyethylene terephthalate as a base polymer, a master
batch containing 15% by weight of polytetrafluoroethylene
particles, which have average particle diameter of 1.8 .mu.m as
measured by an electron microscope, was prepared.
[0065] With the prepared master batch, a polyethylene terephthalate
hollow fiber comprising 48 filaments with 150 denier was produced
by a spinning and direct drawing process. Content of
polytetrafluoroethylene particles in the hollow fiber was
controlled to 2% by weight by regulating content of the master
batch. The hollow fiber had a hollow rate of about 30%.
[0066] 88 strands of the fibers were produced in a drum with 4 kg
capacity, woven by means of an interlock circular knitting machine
with 22 gauge, and dried at a rate of 30 m/min using a hot air
dryer after dyeing at 130.degree. C. for 60 minutes to produce a
circular knitted fabric.
[0067] A result of measuring an abrasion resistance number of the
produced fabric is shown in Table 1.
Comparative Example 1
[0068] A polyethylene terephthalate fiber comprising 36 filaments
with 75 denier and a circular knitted fabric comprising the same
were prepared by the same procedure as in. Example 1, except that
polyethylene terephthalate without polytetrafluoroethylene was
used.
[0069] A result of measuring an abrasion resistance number of the
produced fabric is shown in Table 1.
Comparative Example 2
[0070] A polyethylene terephthalate fiber and a circular knitted
fabric comprising the same were prepared by the same procedure as
in Example 1, except that average particle diameter of
polytetrafluoroethylene particles was altered to 0.001 .mu.m.
[0071] A result of measuring an abrasion resistance number of the
produced fabric is shown in Table 1.
Comparative Example 3
[0072] A sea-island type composite fiber and a circular knitted
fabric comprising the same were prepared by the same procedure as
in Example 5, except that polyethylene terephthalate without
polytetrafluoroethylene was used as the island components.
[0073] A result of measuring an abrasion resistance number of the
produced fabric is shown in Table 1.
Comparative Example 4
[0074] A sea-island type composite fiber and a circular knitted
fabric comprising the same were prepared by the same procedure as
in Example 5, except that average particle diameter of
polytetrafluoroethylene particles was altered to 0.001 .mu.m.
[0075] A result of measuring an abrasion resistance number of the
produced fabric is shown in Table 1.
Comparative Example 5
[0076] A polyethylene terephthalate hollow fiber comprising 48
filaments with 150 denier and a circular knitted fabric comprising
the same were prepared by the same procedure as in Example 6,
except that polyethylene terephthalate without
polytetrafluoroethylene was used.
[0077] A result of measuring an abrasion resistance number of the
produced fabric is shown in Table 1.
Comparative Example 6
[0078] There was an attempt to prepare a polyethylene terephthalate
hollow fiber by the same procedure as in Example 6, except that
average particle diameter of polytetrafluoroethylene particles was
altered to 7.0 .mu.m. However, the desired hollow fiber was not
produced in a commercially available scale due to severe cutting of
yarn during spinning.
[0079] With regard to Examples 1 to 7 and Comparative Examples 1 to
6, abrasion resistance numbers of circular knitted fabrics were
determined according to ASTM-D3884 experiment for knitted products
by means of an evaluation device, for example, a Martin abrasion
tester together with 320Cw sandpaper as an abrasive cloth and with
applied load of 500 g.
TABLE-US-00001 TABLE 1 Example number Abrasion resistance number
(times) Example 1 710 Example 2 900 Example 3 2,200 Example 4 3,000
Example 5 32 Example 6 27 Example 7 32 Comparative example 1 350
Comparative example 2 1,000 Comparative example 3 13 Comparative
example 4 15 Comparative example 5 12 Comparative example 6 Not
detectable
INDUSTRIAL APPLICABILITY
[0080] As described in detail above, the thermoplastic fiber with
excellent durability of the present invention is preferably used in
various applications. More particularly, the inventive
thermoplastic fiber can reinforce durability and abrasion
resistance of light weight fabrics with small finenesses, which are
commercially available for garments. On the other hand, the
thermoplastic fiber of the present invention can be broadly applied
to footwear, furniture, fabrics for protection wears such as riding
coats and bike clothes, in addition to, fabrics for
mountain-climbing backpacks. Further, the thermoplastic fiber can
be employed in industrial applications such as abrasive materials
requiring excellent surface friction resistance properties.
[0081] While the present invention has been described with
reference to the above preferred embodiments, it will be understood
by those skilled in the art that various modifications and
variations may be made therein without departing from the scope of
the present invention as defined by the appended claims.
* * * * *