U.S. patent application number 10/052540 was filed with the patent office on 2003-08-07 for process of generating high hydrophilicity for artifical fiber fabric.
Invention is credited to Chen, J.H., Chen, Richard M. T., Ying, Eric.
Application Number | 20030145389 10/052540 |
Document ID | / |
Family ID | 27658159 |
Filed Date | 2003-08-07 |
United States Patent
Application |
20030145389 |
Kind Code |
A1 |
Chen, Richard M. T. ; et
al. |
August 7, 2003 |
Process of generating high hydrophilicity for artifical fiber
fabric
Abstract
A process for generating high hydrophilicity for artificial
fiber fabric includes the steps of putting an artificial-fiber
fabric to be processed in a closed tank; supplying a gas from a gas
source supplying device into the closed tank; actuating a plasma
exciter to ionize the gas supplied into the closed tank and thereby
produce plasma; and modifying surface of the artificial fiber
fabric in the closed tank with the produced plasma. The processed
artificial fiber fabric shows high moisture absorption and allows
rapid natural evaporation of the absorbed moisture.
Inventors: |
Chen, Richard M. T.;
(Taipei, TW) ; Ying, Eric; (Taipei, TW) ;
Chen, J.H.; (Taipei, TW) |
Correspondence
Address: |
ROSENBERG, KLEIN & LEE
3458 ELLICOTT CENTER DRIVE-SUITE 101
ELLICOTT CITY
MD
21043
US
|
Family ID: |
27658159 |
Appl. No.: |
10/052540 |
Filed: |
January 23, 2002 |
Current U.S.
Class: |
8/115.51 |
Current CPC
Class: |
D06M 2101/16 20130101;
D06M 2101/30 20130101; D06M 10/025 20130101; D06M 2200/00
20130101 |
Class at
Publication: |
8/115.51 |
International
Class: |
D06M 010/00 |
Claims
We claim:
1. A process of generating high hydrophilicity for an artificial
fiber fabric, comprising the following steps: (a) putting said
artificial fiber fabric in a closed tank; (b) supplying a gas from
a gas source supplying device to said closed tank; (c) actuating a
plasma exciter to ionize said gas supplied to said closed tank, so
as to produce plasma gas; and (d) treating said artificial fiber
fabric with said produced plasma to modify surfaces of said fabric,
so that said fabric shows high moisture absorption and allows rapid
natural evaporation of the absorbed moisture.
2. The process as claimed in claim 1, wherein said artificial fiber
fabric is selected from a group consisting of tatted fabrics,
knitted fabrics, and non-woven fabrics.
3. The process as claimed in claim 2, wherein said artificial fiber
fabric is produced with an artificial fiber selected from a group
consisting of polyvinyl fiber, polypropylene fiber, polyester
fiber, nylon fiber, and acrylic fiber.
4. The process as claimed in claim 1, wherein said artificial fiber
fabric includes mix-woven fabric or mixture fabric produced with an
artificial fiber and a natural fiber.
5. The process as claimed in claim 1, wherein a pressure in said
closed tank for ionizing said gas to produce said plasma is ranged
from atmospheric pressure to 30 mtorr.
6. The process as claimed in claim 1, wherein the plasma state gas
is selected from a group consisting of argon (Ar), helium (He),
nitrogen (N.sub.2), oxygen (O.sub.2), and ammonia gas
(NH.sub.3)
7. The process as claimed in claim 1, wherein the plasma exciter
includes radio frequency plasma or microwave frequency plasma.
8. The process as claimed in claim 1, wherein the operating time
for surface modification of artificial fiber fabric is ranged from
1 to 120 seconds.
9. The process as claimed in claim 1, wherein the density of oxygen
and nitrogen atoms on the surface of the artificial fiber fabric
which is surface-modified by plasma increases by 1 to 10% as
compared to an unmodified fabric.
10. The process as claimed in claim 1, wherein the artificial fiber
fabric which is surface-modified by plasma has a absorbed moisture
diffusion velocity of 0.5 to 50 seconds according to JIS
L1096-1990.
11. The process as claimed in claim 1, wherein the artificial fiber
fabric which is surface-modified by plasma has an absorbed moisture
diffusion area that is 1 to 100 times larger than that of the
unmodified fabric.
12. The process as claimed in claim 1, wherein artificial fiber
fabric which is surface-modified by plasma has a capillary rise
height that is 1 to 10 times higher than that of the unmodified
fabric.
13. The process as claimed in claim 1, wherein the artificial fiber
fabric which is surface-modified by plasma has an absorbed moisture
evaporation rate that is 1 to 10 times higher than that of the
unmodified fabric.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a process of generating
high hydrophilicity for an artificial fiber fabric, and more
particularly to a process in which a plasma surface modification is
employed to modify the surface an artificial fiber fabric and
generate high hydrophilicity at its surface.
[0003] 2. Description of the Prior Art
[0004] Market survey indicates that artificial fibers and natural
fibers respectively share 50% of global fiber markets. Due to
limitations in the molecular structure of artificial fibers, a
fabric made of artificial fibers has poorer moisture absorption
ability than that of a fabric made of natural fibers. In other
words, an artificial fiber fabric is inherently hydrophobic. When
the artificial fiber fabric is used in clothing, because of the
hydrophobicity, sweat cannot be effectively and quickly absorbed by
and evaporated via the fabric, causing discomfort on a wearer's
body. It is therefore an important issue for the fabric industry to
improve the hydrophilicity of the artificial fiber fabrics.
[0005] The followings are some well-known techniques currently
employed by manufacturers to improve the hydrophilicity of
artificial fiber fabrics, so that the fabrics show good moisture
absorption ability and good evaporation ability of absorbed sweat
or moisture:
[0006] 1. Production of shaped fiber or hollow porous fiber: In the
process of spinning, changes in the structure of spinning nozzle
and/or addition of surfactant is executed to increase a surface
ratio or a surface area of the produced artificial fiber, so that
moisture on the surface of fiber quickly diffuses via capillary
phenomenon to achieve moisture absorption. However, the shaped
fiber tends to deform and adversely affect its moisture absorption.
Moreover, external particles attached to grooves on the surface of
the shaped fiber in the process of dyeing and finishing largely
reduce the moisture absorption and prevent the evaporation of
absorbed moisture via the shaped fiber.
[0007] 2. Treatment with hydrophilic agent: In the finishing
treatment of an artificial fiber fabric, hydrophilic agent is added
into a pressurized tank to spread over the fabric surface. A
disadvantage of the hydrophilic agent treated fabric is an inferior
washing resistance or washing fastness thereof. The hydrophilic
agent treated fabric tends to lose its hydrophilicity after several
times of washing.
[0008] 3. Formation of multilayer texture structure: Natural fibers
and artificial fibers are spun or woven into double or triple layer
texture structure. A fabric of multilayer texture structure formed
in this way has improved hydrophilicity but is produced with
complicate technique and accordingly at increased manufacturing
cost.
SUMMARY OF THE INVENTION
[0009] A primary object of the present invention is to provide a
process for generating high hydrophilicity for an artificial fiber
fabric to eliminate drawbacks existing in the conventional ways of
producing hydrophilic artificial fiber fabrics.
[0010] Another object of the present invention is to provide an
artificial fiber fabric that shows good moisture absorption ability
and good evaporation ability of absorbed sweat. A process for
forming this type of artificial fiber fabric includes a step of
fiber surface modification to improve the hydrophilicity of the
fabric.
[0011] A further object of the present invention is to provide a
process for modifying an artificial fiber fabric with plasma, so
that the treated fabric shows high moisture absorption and allows
quick natural evaporation of the absorbed moisture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The method and the technical means adopted by the present
invention to achieve the above and other objects can be best
understood by referring to the following detailed description of
the preferred embodiments and the accompanying drawings,
wherein:
[0013] FIG. 1 is a schematic diagram showing a system for
implementing the process of the present invention for generating
high hydrophilicity for an artificial fiber fabric; and
[0014] FIG. 2 is a flowchart showing steps included in the process
of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The present invention relates to a new technique for
generating excellent hydrophilicity for an artificial fiber fabric,
such as nylon, polyester or mix woven fabric. In the process of the
present invention, plasma is employed to modify the surface of an
artificial fiber fabric, so that the modified fabric shows high
moisture absorption and allows quick evaporation of the absorbed
moisture. When the fabric treated with the process of the present
invention is applied to clothing, sweat perspired by a wearer could
be quickly absorbed by and naturally evaporated via the fabric to
keep the wearer's body dry and fresh.
[0016] Please refer to FIG. 1 that is a schematic diagram showing a
treatment system for implementing the process of the present
invention to generate high hydrophilicity for an artificial fiber
fabric. As shown, the treatment system mainly includes a closed
tank 1, and a plasma exciter 2 and a gas source supplying device 3
connected to the closed tank 1. With the treatment system shown in
FIG. 1, the present invention provides a plasma surface
modification to treat an artificial-fiber fabric 4 for the same to
show good hydrophilicity.
[0017] The fabric 4 to which the process of the present invention
can be applied includes tatted fabrics, knitted fabrics, and
non-woven fabrics produced with artificial fibers, such as
polyvinyl fiber, polypropylene fiber, polyester fiber, nylon fiber,
acrylic fiber, etc., as well as mix-woven fabrics or mixture
fabrics produced with any of the above-mentioned artificial fibers
and any type of natural fibers.
[0018] In the process of the present invention, the fabric 4 to be
treated is put in the closed tank 1, and a gas is supplied to the
closed tank 1 from the gas source supplying device 3. By means of
excitation of the plasma exciter 2, the gas is repeatedly
transferred between high energy level and stable energy level, and
emits photons. Plasma is a partially ionized gas that is composed
of a large quantity of neutral gas and a small quantity of cations
and electrons. When a neutral substance is applied with energy,
such as a high temperature or accelerated electrons and/or
accelerated ions, the neutral substance is excited, dissociated and
ionized to produce plasma.
[0019] In the treatment system employed in the present invention,
the plasma exciter 2 may include, for example, radio frequency
plasma or microwave frequency plasma. Non-polymerized gas that may
be used to produce the plasma-state gas includes argon (Ar), helium
(He), nitrogen (N.sub.2), oxygen (O.sub.2), and ammonia gas
(NH.sub.3). Pressure in the closed tank 1 for the radio frequency
plasma or the microwave frequency plasma to excite to the plasma
state is ranged from atmospheric pressure to 30 mtorr. When the
artificial fiber fabric 4 is subjected to surface modification by
treating it with the plasma obtained from the ionized gas, it shows
high moisture absorption and allows rapid natural evaporation of
the absorbed moisture therefrom.
[0020] FIG. 2 is a flowchart showing steps included in the process
of the present invention. In the processes, an artificial fiber
fabric to be processed is first prepared (step 101). The prepared
fabric is then put in a closed tank (step 102). A gas is supplied
from a gas source supplying device into the closed tank (step 103).
A plasma exciter is actuated to excite the gas supplied to the
closed tank to repeatedly transfer between high energy level and
stable energy level and form plasma (step 104). Surfaces of the
fabric positioned in the closed tank are modified by the produced
plasma and exhibit excellent hydrophilicity (step 105).
[0021] After the prepared fabric has been modified by the produced
plasma for 1 to 120 seconds, the modified sample is analyzed with a
surface analyzer. It is found a density of oxygen and nitrogen
atoms on the surface of the treated fabric sample increases by 1 to
10%, as compared to an unmodified fabric sample.
[0022] When an unmodified fabric sample and a modified fabric
sample are tested under the same conditions and environments for
various moisture absorption and evaporation indexes thereof, the
following differences between them are found:
[0023] 1. The fabric sample modified by the plasma state gas has an
absorbed moisture diffusion velocity of 0.5 to 50 seconds according
to JIS L1096-1990.
[0024] 2. The fabric sample modified by the plasma state gas has an
absorbed moisture diffusion area that is 1 to 100 times larger than
that of the unmodified fabric sample.
[0025] 3. The fabric sample modified by the ionized plasma state
gas has a capillary rise height that is 1 to 10 times higher than
that of the unmodified fabric sample.
[0026] 4. The fabric sample modified by the plasma state gas has an
absorbed moisture evaporation rate that is 1 to 10 times higher
than that of the unmodified fabric sample.
[0027] Before conducting various tests for the moisture absorption
and evaporation indexes, all the fabric samples are dried at
120.degree. C. for 30 minutes to ensure complete removal of
moisture from the samples to be tested. The dried samples are then
positioned still under a room temperature of 22.+-.2.degree. C. and
a relative humidity of 65.+-.10% for more than 24 hours. In this
manner, the fabric samples to be tested may have moisture content
within a reasonable range to avoid errors in the tests due to an
overloaded high moisture content in the samples.
[0028] The following are some examples in which the process of the
present invention is employed to improve the hydrophilicity of the
artificial fiber fabric 4. It is understood these examples are only
some applications rather than a complete scope of the present
invention. In these examples, five different testing samples
numbered from 1 to 5 are used. The testing sample No. 1 is a plain
tatted fabric produced with 100% nylon fiber and having a unit
weight of 119 g/m.sup.2; the testing sample No. 2 is a twill tatted
fabric produced with 100% polyester fiber and having a unit weight
of 103 g/m.sup.2; the testing sample No. 3 is a satin tatted fabric
produced with 45% polyester fiber and 55% nylon fiber and having a
unit weight of 111 g/m.sup.2; the testing sample No. 4 is a twill
tatted fabric produced with 100% nylon fiber and having a unit
weight of 110 g/m.sup.2; and the testing sample No. 5 is a twill
tatted fabric produced with 100% polyester fiber and having a unit
weight of 103 g/m.sup.2. Surface modification of the above five
testing samples is effectuated by treating them with different
plasma state gases excited with high-frequency electric wave or
microwave based on the process of the present invention.
[0029] Treatment conditions adopted in the five examples of the
present invention are listed in the following Table I.
1TABLE I Excitation Operating Time of Sample Plasma Excitation
Power Pressure Treatment No. State Gas Frequency (W) (mtorr)
(second) Example 1 O.sub.2 13.56 MHz 800 300 30 Example 2 NH.sub.3
13.56 MHz 1000 300 30 Example 3 O.sub.2 13.56 MHz 300 300 10
Example 4 Ar 13.56 MHz 300 300 30 Example 5 O.sub.2 2.45 GHz 900
200 10
[0030] To find out the effect of the process of the present
invention on the hydrophilicity of artificial fiber fabrics, the
above five testing samples Nos. 1 to 5 having been treated with the
present invention and three other untreated samples Nos. 1 to 3 for
comparsion are tested for various moisture absorption and
evaporation indexes thereof. The comparison sample No. 1 is a plain
tatted fabric produced with 100% nylon fiber and having a unit
weight of 119 g/m.sup.2; the comparison sample No. 2 is a twill
tatted fabric produced with 100% polyester fiber and having a unit
weight of 103 g/m.sup.2; and the comparison sample No. 3 is a satin
tatted fabric produced with 45% polyester fiber and 55% nylon fiber
and having a unit weight of 111 g/m.sup.2.
[0031] It is to be noted that all the above-mentioned testing
samples and comparison samples are fabrics after dyeing and
finishing treatment but not processed with any of the conventional
techniques for improving the hydrophilicity thereof. That is, all
the above samples are not produced with shaped or hollow porous
fibers, not added with any hydrophilic agent, and not multilayer
texture structure.
[0032] All the testing samples and comparison samples are dried at
120.degree. C. for 30 minutes, and then positioned still in a
moisture-regain box for 24 hours.
[0033] The moisture-regain box has a controlled relative humidity
of 65.+-.5% and a controlled temperature of 22.+-.2.degree. C.
Thereafter, various tests for moisture absorption and evaporation
indexes are conducted on these samples. The test results are shown
in the following Table II.
2 TABLE II Absorbed Absorbed Absorbed Moisture Moisture Moisture
Diffusion Diffusion Evaporation Velocity Area Capillary Rise Rate
Sample No. (second) (cm.sup.2) Height (cm) (%) Testing 2.5 40.0
12.5 90 sample No.1 Testing 3.2 50.1 10.2 75 sample No.2 Testing
1.7 53.1 7.7 90 sample No.3 Testing 2.0 41.3 12.5 78 sample No.4
Testing 3.5 41.8 11.6 90 sample No.5 Comparison 124 12.4 4.4 25
sample No.1 Comparison >600 17.2 4.3 40 sample No.2 Comparison
108 2.2 1.7 40 sample No.3
[0034] To ensure the precision of test, all the tests are conducted
under specific environments with controlled relative humidity and
temperature. That is, the test results shown in Table II are
obtained with the testing temperature maintained at 22.+-.2.degree.
C. and the relative humidity controlled at 65.+-.5%. Wherein, the
absorbed moisture diffusion velocity test is conducted in
accordance with JIS L1096-1990 6.26A; the capillary rise height
test is conducted in a longitudinal direction in accordance with
JIS L1096-1990 6.261B; the absorbed moisture diffusion area test is
conducted by dripping 0.2 ml of distilled water on a testing sample
fabric from a position 5 cm above the sample fabric and measuring
the diffusion area of the dripped water after 30 seconds; and the
absorbed moisture evaporation rate is tested by preparing and
weighing a sample fabric of 10 cm.times.10 cm in size, dripping 1.0
ml of distilled water on the sample fabric, positioning the sample
fabric still in a chamber maintained at constant temperature and
relative humidity for 10 minutes, and weighing the sample fabric
again to calculate the absorbed moisture evaporation rate
thereof.
[0035] From the test results of the above examples applying the
process of the present invention, it is proven the artificial fiber
fabrics treated with the process of the present invention are
indeed improved in their hydrophilicity to show quick moisture
absorption and allow rapid natural evaporation of the absorbed
moisture. The process of the present invention for generating high
hydrophilicity for an artificial fiber fabric is therefore
industrially practical for use.
[0036] Although the present invention has been described with
reference to the preferred embodiments and the best mode of
operation thereof, it is apparent to those skilled in the art that
a variety of modifications and changes may be made without
departing from the scope of the present invention which is intended
to be defined by the appended claims.
* * * * *