U.S. patent application number 10/097372 was filed with the patent office on 2002-09-19 for method of decolorizing blue jeans based on client-desired design.
Invention is credited to Kim, Myung Han.
Application Number | 20020129450 10/097372 |
Document ID | / |
Family ID | 19706973 |
Filed Date | 2002-09-19 |
United States Patent
Application |
20020129450 |
Kind Code |
A1 |
Kim, Myung Han |
September 19, 2002 |
Method of decolorizing blue jeans based on client-desired
design
Abstract
The present invention provides a method of decolorizing blue
jeans based on a client-desired design. Hydrochloric acid (HOCl)
and sodium chloride solution are provided to an electrolytic tub,
and are electrolyzed to generate chlorine gas and hydrogen gas.
Hypochlorous acid solution is separated from sodium hydroxide.
Tapes are attached to the blue jeans to make a constant form. The
tape-attached blue jeans are submerged in the hypochlorous acid to
change a colorant of the blue jeans.
Inventors: |
Kim, Myung Han; (Richmond,
VA) |
Correspondence
Address: |
STAAS & HALSEY LLP
700 11TH STREET, NW
SUITE 500
WASHINGTON
DC
20001
US
|
Family ID: |
19706973 |
Appl. No.: |
10/097372 |
Filed: |
March 15, 2002 |
Current U.S.
Class: |
8/115.51 |
Current CPC
Class: |
D06P 5/153 20130101;
D06B 11/0096 20130101 |
Class at
Publication: |
8/115.51 |
International
Class: |
D06M 010/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 15, 2001 |
KR |
2001-13372 |
Claims
What is claimed is:
1. A method of decolorizing blue jeans, comprising the steps of:
(a) providing and electrolyzing hydrochloric acid (HOCl) and sodium
chloride solution to an electrolytic tub to generate chlorine gas
and hydrogen gas, and separating hypochlorous acid solution from
sodium hydroxide; (b) attaching tapes to the blue jeans to make a
constant form; and (c) submerging the tape-attached blue jeans in
the hypochlorous acid to change a colorant of the blue jeans.
2. The method as recited in claim 1, further comprising a step of
reacting hydrogen chloride gas with the sodium hydroxide solution
to produce sodium chloride solution, wherein the hydrogen chloride
gas is generated by trapping and reacting the chlorine and hydrogen
gases with each other.
3. The method as recited in claim 2, wherein in the step (c), the
colorant is oxidized and a reaction is made to change the
hypochlorous acid to the hydrochloric acid.
4. The method as recited in claim 3, wherein the changing the
colorant is made in the electrolytic tub and a processing tub; and
wherein the producing the sodium chloride solution is made in the
electrolytic tub and a scrubber, further comprising a step of
recycling the hydrochloric acid in the processing tub and the
sodium chloride solution in the scrubber to the electrolytic
tub.
5. The method as recited in claim 4, wherein the steps are
simultaneously performed and each of the steps is continuously
performed.
6. The method as recited in claim 1, wherein the changing the
colorant is made at a temperature between 10.degree. C. and
30.degree. C.
7. The method as recited in claim 1, wherein the sodium chloride
solution provided to the electrolytic tub contains sodium chloride
of 0.1-7% by weight.
8. The method as recited in claim 1, before the step (c), further
comprising a step of additionally colorizing the blue jeans with an
oil-based colorant oxidized by the hypochlorous acid to make a
constant form.
9. A method of decolorizing blue jeans, comprising the steps of:
(a) providing and electrolyzing hydrochloric acid (HOCl) and sodium
chloride solution to an electrolytic tub to generate chlorine gas
and hydrogen gas, and separating hypochlorous acid solution from
sodium hydroxide; (b) additionally colorizing the blue jeans with
an oil-based colorant oxidized by the hypochlorous acid to make a
constant form; and (c) submerging the tape-attached blue jeans in
the hypochlorous acid to change a colorant of the blue jeans.
10. The method as recited in claim 9, wherein the oil-based
colorant is identical to a colorant colorized on the blue jeans and
in the step (b), colorization amount is controlled at each part of
the blue jeans through a plurality of control steps.
Description
RELATED APPLICATION
[0001] This application relies for priority upon Korean Patent
Application No. 2001-13372, filed on Mar. 15, 2001, the contents of
which are herein incorporated by reference in their entirety.
DESCRIPTION
[0002] The present invention is a method of decolorizing blue jeans
and, more particularly, to a method of decolorizing blue jeans
based on the client-desired design.
BACKGROUND OF THE INVENTION
[0003] Blue jeans are trousers that are made of fabrics obtained by
colorizing closely woven fabric with blue colorant such as indigo
blue dye. Therefore, the blue jeans become favorite jeans due to
toughness, durability, and practicality. Like other fashion
clothes, blue jeans have kept pace with various tastes or liking of
users by changing their forms and colors.
[0004] Since blue jeans are originally rough as well as tough, a
user, maker or merchant often intentionally makes the blue jeans
worn out by a sandblasting or stonewashing process. The colors of
initially colorized blue jeans are generally dark, so that there
may be a need for partial decolorization thereof by reacting with a
decolorant such as sodium hypochlorite (HOCl) during a drum
processing. Furthermore, by attaching tapes to parts of the blue
jeans during decolorization thereof, the parts are not decolorized
to attain desired patterns or shapes.
[0005] However, conventional methods of making patterns on the blue
jeans have difficulty in attaining desired patterns and clear
colors. In a conventional decolorization process, a chemical
solution such as sodium hypochlorite or calcium hypochlorite is put
into an amount of water having a temperature between 60.degree. C.
and 80.degree. C. (if necessary, abrading materials are added).
Together with the water containing the chemical solution, blue
jeans are rotated in a drum for 30 minutes or longer. In a case
where tapes are attached to the blue jeans in order to attain a
desired pattern, the water or other chemical materials may have an
influence on the tapes. In addition, a high processing temperature
may soften an adhesive element and turbulence may cause the tapes
to thrust out from their original positions. Therefore, it is hard
to attain the desired pattern. Further, if the tapes are thrust out
from the blue jeans during the decolorization, tape-attached parts
are also decolorized to make it hard to attain a clear color and
pattern.
[0006] Also, the conventional decolorization method demands high
costs for raising the temperature of a processing solution and
continuously providing sodium hypochlorite and an amount of water.
Wastewater is inevitably produced in the conventional
decolorization. When the wastewater is discharged to a river,
environmental pollution results. Therefore, if the wastewater is
treated and discharged, additionally costs are incurred.
SUMMARY OF THE INVENTION
[0007] A main purpose of the present invention is to provide a
method of decolorizing blue jeans with a clear color and a desired
design.
[0008] Another purpose of the present invention is to provide an
environment-friendly method of decolorizing blue jeans, which is
capable of preventing waste, pollution, and waste treating
cost.
[0009] Still another purpose of the present invention is to provide
a method of decolorizing blue jeans, which is capable of cutting
down decolorization cost by retrieving a chemical material to be
used as a treatment material in waste produced during
decolorization.
[0010] One aspect of the present invention is a method of
decolorizing blue jeans using the steps of ;providing hydrochloric
acid and sodium chloride solution to an electrolytic tub to
generate chlorine gas and hydrogen gas, separating hypochlorous
acid (HOCl) solution from sodium hydroxide, attaching tapes to the
blue jeans to make a constant form, and submerging the
tape-attached blue jeans in the hypochlorous acid to change the
color of the blue jeans.
[0011] Another aspect of the present invention consists of
providing hydrochloric acid (HOCl) and sodium chloride solution to
an electrolytic tub to generate chlorine gas and hydrogen gas,
separating hypochlorous acid solution from sodium hydroxide,
colorizing the blue jeans with an oil-based colorant oxidized by
the hypochlorous acid to make a constant form, and submerging the
tape-attached blue jeans in the hypochlorous acid to change the
color of the blue jeans.
[0012] The oil-based colorant is identical to a colorant colorized
on the blue jeans. When additionally colorizing the blue jeans,
colorization amount is controlled at each part of the blue jeans
through a plurality of control steps.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a concept diagram showing the general structure of
one example of an apparatus for decolorizing blue jeans according
to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] Although specific terms are used in the following
description for the sake of clarity, these terms are intended to
refer only to the particular feature of the invention selected for
illustration and are not intended to define or limit the scope of
the invention.
[0015] Referring now to FIG. 1, an apparatus for decolorizing blue
jeans includes an electrolytic tub 10. A semipermeable membrane 7
is placed in the center of the electrolytic tub 10. In the early
stage, a small amount of hydrochloric (HCl) solution and sodium
chloride (NaCl) solution are provided to the electrolytic tub 10.
Preferably, NaCl is 0.1-7% solution by weight.
[0016] The electrolytic tub 10 has a cathode 5 and an anode 3.
Generally, the cathode 5 is made of one selected from the group
consisting of platinum, platinum-plated conductor, a material of
high electric conductivity that is not eroded by sodium hydroxide,
and the anode 3 is made of stainless steel that is strong for the
erosion. If a voltage is applied to the cathode 5 and the anode 3
by supplying a power thereto, sodium ions dissociated from sodium
chloride are induced to the cathode 5. As a result, an electron is
gained to generate sodium metal.
[0017] The sodium metal immediately reacts with water to produce
sodium hydroxide. The sodium hydroxide is dissolved in the water to
produce sodium hydroxide solution. At this time, hydrogen gas is
produced and exhausted. Chlorine ions are induced to the anode 3,
so that an electron is lost to produce a chlorine molecule. A part
of the chlorine molecule is gasified to be exhausted into the air,
and another part reacts with the water to produce hydrogen chloride
and hypochlorous acid. The hydrogen chloride and the hypochlorous
acid are immediately dissolved in the water to produce
hydrochloride solution and hypochlorous solution. The hypochlorous
acid (HOCl) is an oxidant having a strong oxidizing power. The
oxidizing power of the hypochlorous acid (HOCl) is 40-80 times
stronger than that of sodium chlorate (NaOCl) which is an element
of a commercial sterilizing-bleaching agent. Although the membrane
7 isolates a cathode space 8 from an anode space 9, sodium ions,
chlorine ions, and hydrogen ions are permeated well.
[0018] Therefore, the content of sodium chloride in the
electrolytic tub 10 is reduced as time passes. Further, the
electrolytic tub 10 has the hydrochloride and hypochlorous
solutions that are intensively concentrated on the anode and
cathode spaces 9 and 8. Since hydrochloric acid is induced to each
of the cathode 5 and anode 3 to produce a part of chlorine and
hydrogen, it is not intensively concentrated thereon. Generating
materials of each of the cathode 5 and anode 3 are represented by
chemical formulas 1 and 2 below.
Cl.sub.2+H.sub.2O=HCl+HOCl [Chemical Formula 1]
2Na+2H.sub.2O=2NaOH+H.sub.2 [Chemical Formula 2]
[0019] The electrolytic tub 10 is connected, via a processing pipe,
to a processing tub 30 in which a process for decolorizing blue
jeans is carried out. The processing pipe has an output pipe making
a material flow from the processing tub 30 to the electrolytic tub
10, and an input pipe 18 making a material flow from the
electrolytic tub 10 to the processing tub 30. A pump and valves for
making solution flow are installed at the input pipe 18 and the
output pipe. In this case, the input pipe 18 may also serve as the
output pipe (i.e., one pipe may serve as input and output pipes)
and the pump enables the solution to bi-directionally flow.
[0020] If a concentration of the hypochlorous acid reaches a
predetermined level in the anode space 9 of the electrolytic tub
10, solution in the anode space 9 flows to the processing tub 30
via the input pipe 18.
[0021] A chlorine trap duct 14 and a hydrogen trap duct 12 are
installed at the electrolytic tub 10. The chlorine trap duct 14
traps chlorine produced over the anode space 9, and the hydrogen
trap duct 14 traps hydrogen produced over the anode space 8. Also,
the ducts 12 and 14 are connected to a scrubber 20 for processing a
gas via a duct pipe 16 for carrying the gas. On the duct pipe 16, a
fan FAN may be installed for helping to carry a gas and easily
trapping the gas. A confluence may be formed in a center of the
duct pipe 16 to mix trapped gases with one another.
[0022] Alternatively, the confluence may serve as a reaction
chamber just before scrubbing the trapped gases. In the confluence,
hydrogen reacts with chlorine to produce a hydrogen chloride gas
that is provided to a processing chamber in the scrubber 20.
[0023] A shower facility 22 is installed entirely over the
processing chamber in the scrubber 20. A shower pipe 26, which is
connected to the cathode 8 of the electrolytic tub 10, is connected
to the shower facility 22. A pump and a valve are mounted on the
shower pipe 26 to carry a chemical solution (here, sodium hydroxide
filling most part of the cathode 8) to the processing chamber in
the scrubber 20. In the processing chamber, the sodium hydroxide
solution is sprayed through the shower facility 22. Most of the
sprayed sodium hydroxide solution reacts with the hydrogen chloride
provided to the processing chamber to produce a sodium chloride
solution. Most of the sodium chloride solution directly drops to a
retrieving tub incorporated with the processing chamber. Scattered
minute solution drops are condensed and trapped by a de-mister
installed at an upper part of the scrubber 20, and then flows into
the retrieving tub.
[0024] Thus, contaminants are not discharged to the air while only
innoxious gases are exhausted via the scrubber 20. In the
confluence of the duct pipe 16 and the scrubber 20, a chemical
reaction is represented by chemical formulas 3 and 4 below.
H.sub.2+Cl.sub.2=2HCl [Chemical Formula 3]
HCl+NaOH=NaCl+H.sub.2O [Chemical Formula 4]
[0025] A sodium chloride solution is put into a retrieving tub 24
that is located at a lower part of the scrubber 20. The retrieving
tub 24 is connected to the electrolytic tub 10 via a retrieving
pipe 32 having a valve and a pump. Thus, the sodium chloride
solution, which is generated in the scrubber 20 via the retrieving
pipe 32, is carried to the electrolytic tub 10. Since elements of
the sodium chloride solution are all originated from the
electrolytic tub 10, processing elements are to be retrieved.
[0026] Decolorization-desired blue jeans 31 are submerged, for a
predetermined time, in the processing tub 30 with the hypochlorous
acid (partially containing hydrochloric acid or other materials)
carried from the cathode and anode spaces 8 and 9. Since tapes
protect partial surfaces of the blue jeans 31, a chemical reaction
is suppressed at tape-attached parts. On the other hand, in
unprotected parts, colorant elements for making a color of the blue
jeans 31 react with the hypochlorous acid. This results in
considerable oxidation of the unprotected parts. Further, a
chlorination reaction may occur partially. Owing to the strong
oxidizing power of the hypochlorous acid, the reaction is made at a
temperature between 10.degree. C. and 30.degree. C., preferably
between 18.degree. C. and 26.degree. C. While it is appreciated
that the submerging time is variable with the processing
conditions, two to ten minutes are sufficient. Preferably, the
tapes do not damage clothes of the blue jeans although they are
removed after the decolorization process, and are treated by an
adhesive agent which does not weaken an adhesive power in spite of
reaction with water or other decolorization chemicals.
[0027] With variation of the colorant elements, the blue jeans are
gradually decolorized. A degree of the decolorization is
controllable with the submerging time, a concentration of the
hypochlorous acid, a processing temperature. Since the hypochlorous
acid used to decolorize the blue jeans 31 are changed to hydrogen
chloride, the hypochlorous acid solution in the processing tub 30
is changed to a solution mainly containing a diluted hydrochloric
acid when the decolorization process is performed therein.
[0028] The diluted hydrochloric acid solution is provided to the
electrolytic tub 10 via the output pipe of the processing pipe. The
diluted hydrochloric acid solution is also made up of materials
provided from the electrolytic tub 10. Therefore, a process for
providing the diluted hydrochloric acid solution may be called a
retrieving process. A chemical reaction in the processing tub 30 is
represented by chemical formulas 5 and 5 below.
R--H+HOCl=R--OH+HCl [Chemical Formula 5]
R--H+HOCl=R--Cl+H.sub.2O [Chemical Formula 6]
[0029] wherein the R group (R--) is an atomic group having any
structure, and a conventional colorant element is made up of an
organic group.
[0030] Generally, oxidized or chlorinated colorant elements are
continuously attached to the blue jeans. For that reason, the
oxidized or chlorinated colorant elements are not diffused to the
processing tub 30 and the diluted hydrochloric acid can be
retrieved. If the changed colorant elements are separated from the
blue jeans to contaminate the processing tub 30, they must be
eliminated by performing an extra treatment process.
[0031] Although it has been described that all the steps are
separately performed in this embodiment, a continuous process may
be made in which each pipe continuously puts a material out by
controlling a rotation speed based on a content of provided
materials and an apparatus and environmental conditions such as
temperature and pressure for each processing reaction. Since the
continuous process does not require manpower for operating a valve
or pump of each pipe, automation and mechanization can easily be
realized in the whole process.
[0032] According to the present invention, because hypochlorous
acid having a strong oxidizing power is used, it is not necessary
to raise a processing temperature. Therefore, tapes are not
separated from the blue jeans during a process for decolorizing the
blue jeans to obtain a design of client-desired form and clearness.
Further, all materials are circulated except oxygen or chlorine. If
water for supplementing oxygen and a part of exhausted gas or a
chlorine gas is supplemented, the process for decolorizing blue
jeans can continuously be performed only by supplying electricity.
Compared with a conventional process in which all decolorizing
elements are provided anew for one time treatment and waste is
inevitably created, the decolorizing process according to the
invention can be recycled only by supplying electricity and
supplementing eliminated elements. Thus, costs for providing
material and treating waste can be saved. First of all, the present
invention makes it possible to realize an environment-friendly
process.
* * * * *