Cloth treatment method by electric current

Abstract: A cloth treatment method comprising the steps of dipping a cloth to be treated in a treating solution, squeezing the cloth, laying the cloth wet and impregnated with the treating solution over between two electrode rolls opposed in parallel to each other, and applying a voltage to the two electrode rolls to pass an electric current between the two electrode rolls through the treating solution with which the cloth is impregnated, thereby a heat being generated due to electric resistance of the treating solution.

Description: The invention relates to a method for treating a cloth with the features of the preamble of the only claim as known from US-A-4574413. In the method according to US-A-4574413, the electrodes are arranged alternately, anode and cathode are in direct contact with the cloth between them. The electrodes are all arranged in one line. From FR-A-2064150, a method of treating a cloth is known, in which two anode side electrode rolls are horizontally disposed in such a manner as to be opposed to two horizontally disposed cathode side electrode rolls. Between these two pairs of rolls the cloth is guided horizontally A voltage is applied to the electrodes to pass an electric current between the electrodes along the cloth. The contact area between the rolls and the cloth is rather narrow. The present invention has the object of providing a cloth treatment method by which continuous treatment of a cloth in a spread state can be carried out with a simple mechanism, even a cloth of small dimensions or length can be easily dyed, and deep color adjustment can be also easily carried out. In order to achieve the foregoing object, the cloth treating method in accordance with the present invention is characterized by the features of the only claim. In the cloth treatment method of above arrangement, when applying a voltage to the two electrode rolls, a part of electric energy passing through the treating solution with which the cloth to be treated is impregnated is converted to a heat energy by generation of heat due to electric resistance of the treating solution, whereby temperature of both treating solution and cloth is increased, thus the treating substance contained in the treating solution being physically and chemically fixed to the cloth. The treated cloth can be continuously treated and conveyed outside by the rotation of each electrode roll. Because the cloth in a spread state is wound round over between the two electrode rolls, there is no need of such troublesome work as spreading the cloth after completing the treatment, which results in sparing of treating time. Because electric energy is used as a heating energy and electric current is directly applied to the treating solution, a very simplified mechanism is sufficient for increasing temperature of the cloth as compared with the conventional system wherein vapor or hot air is used as a heating source. Because the electric current passes almost evenly through the cloth, there is no problem of deep coloring, and any temperature required for the treatment can be easily obtained by adjusting the voltage applied. A cloth of small length and dimensions can be also easily treated by changing the number of electrode rolls used. Furthermore, the cloth treatment method is also adaptable for mass treatment. Other objects and advantages of the invention will become apparent in the course of the following description with the accompanying drawings. Figure 1 is a schematic sectional view illustrating an example of a treatment apparatus used for embodying the cloth treatment method in accordance with the present invention; and Figure 2 is a perspective view to explain the basic arrangement of the cloth treatment method. A preferred embodiment of the present invention is now described hereinafter with reference to the accompanying drawings. Describing first the basic technological arrangement of the invention referring to Figure 2, the anode side electrode roll 10 and the cathode side electrode roll 12 both composed of a conductor are opposedly disposed with a certain distance therebetween. Anode and cathode of the DC power supply 14 are respectively connected to the electrode rolls 10, 12. The cloth 16 to be treated is dipped in the treating solution, then squeezed in such a manner as to be uniformly impregnated with the treating solution. The wet cloth 16 is placed over between the two electrode rolls 10, 12. When applying a DC voltage from the DC power supply 14 to the two electrode rolls 10, 12, because the cloth 16 being impregnated with the treating solution is in electrical contact with the two electrode rolls 10, 12, a DC current passes from the anode of the DC power supply 14 to the cathode thereof by way of the anode side electrode roll 10, the treating solution impregnated into the cloth 16 and the cathode side electrode roll 12. At this time, temperature of the cloth 16 is raised by heat generation of the treating solution because of electric resistance of the solution. Thus the temperature can be raised to 90 to 100°C necessary for dyeing just by controlling the applied voltage from the DC power supply 14. The arrangement of Figure 2 does not fall within the scope of the claim. Figure 1 is a schematic view of one example of the apparatus used for embodying the cloth treating method of the invention. In the drawing, the cloth 16 to be treated is dipped in the treating solution 22 in the treating solution tank 20 through the guide roll 18, then squeezed by a pair of squeezing rolls 24, 26 in such a manner as to be impregnated uniformly with the treating solution 22, and thereafter guided into the treating chamber 28. A plurality of anode side electrode rolls 10a to 10n are horizontally disposed in the treating chamber 28 at the upper portion with a certain distance between one and the other in such a manner as to be opposed respectively to each portion located between one and the other of a plurality of cathode side electrode rolls 12a to 12m. The cloth 16 guided into the treating chamber 28 is alternately wound round the anode side electrode rolls 10a to 10n and the cathode side electrode rolls 12a to 12m, and conveyed in the direction of the arrow by rotational drive of a torque motor (not illustrated) to be finally sent outside the treating chamber 28. The anode side electrode rolls 10a to 10n and the cathode side electrode rolls 12a to 12m are respectively connected to the anode and cathode of the DC power supply so that a DC voltage corresponding to treatment speed may be applied to the anode side electrode rolls 10a to 10n and the cathode side electrode rolls 12a to 12m, thereby the anode side electrode rolls 10a to 10n being rotationally driven to convey the cloth 16. The treating solution 22 with which the cloth 16 is impregnated is heat-generated as described above referring to Figure 2, thereby temperature of the cloth 16 being raised, and accordingly such treating substance as dye or resin contained in the treating solution 22 is fixed to the cloth 16. As electricity is used as heating source of the cloth 16 in this embodiment, no vapor is needed being different from the conventional treatment. But it is also desirable to provide auxiliarly heating with a certain amount of vapor to accelerate the dyeing process. As the cloth 16 is wound round each of the electrode rolls 10a to 10n and 12a to 12m in its spread state, there is no need of such troublesome work as spreading the cloth 16 after the treatment. Varieties of cloths 16 can be continuously treated because number of electrode rolls 10a to 10n and 12a to 12m is variably changed according to the condition of the cloth 16. The inventor actually carried out several experiments to acknowledge that cloths treated by the method of the invention have their performance suitable for conditions of normal use, and results of the experiments are described hereinafter. (1) Dyeing with direct dyes: A bleached cotton cloth of 130 g/m² in weight was once dipped in a dyeing solution of 10 g/ℓ Kasyarus Spura Browm GTL (trade name: produced by Nippon Kayaku Co., Ltd.), then was once squeezed at the squeezing percentage of 85 %. The wet cotton cloth was laid over between the two electrode rollers 10, 12 illustrated in Figure 2, and a load of 100 g was applied to both ends of the cloth. When applying 130 V for 20 seconds from the DC power supply 14 while keeping the loaded state, temperature of the cloth was raised to 90°C, when dyeing reaction took place, thus a cloth of required color was obtained after washing with water and drying. (2) Dyeing with cationic dye: A 100% acrylic desized cloth of 180 g/m² in weight was once dipped in a mixed treating solution of 10 g/ℓ Kayacryl Yellow 3RL-ED (trade name: produced by Nippon Kayaku Co., Ltd.), 1 g/ℓ Kayacryl Red GRL-ED (same as above), 0.5 g/ℓ Kayacryl Blue GRL-ED (same as above) and 3 mℓ/ℓ Naganol (trade name of an organic acid produced by Sanpo Chemical Industry Co. Ltd.), then was once squeezed at the squeezing percentage of 75 %. The wet cloth was laid over between the two electrode rollers 10, 12 illustrated in Figure 2, and a load of 100 g was applied to both ends of the cloth. When applying 120 V for 20 seconds from the DC power supply 14 while keeping the loaded state, temperature of the cloth was raised to 95°C, when dyeing reaction took place, thus a cloth of required color was obtained. (3) Polyester reducing (finishing): A polyester desized cloth of 120 g/m² in weight was once dipped in a mixed treating solution of 250 g/ℓ caustic soda and 3 mℓ/ℓ penetrant, then was once squeezed at the squeezing percentage of 85 %. The wet cloth was laid over between the two electrode rollers 10, 12 illustrated in Figure 2, and a load of 100 g was applied to both ends of the cloth. When applying 120 V for 25 seconds from the DC power supply 14 while keeping the loaded state, temperature of the cloth was raised to 95°C. After turning off electricity, the cloth was subjected to washing with water, neutralization by dipping in 2 mℓ/ℓ acetic acid for 30 seconds, washing with water for 1 minute, dehydration squeezing at the squeezing percentage of 75 % with mangle, and drying at 120°C for 3 minutes in order. Thus a cloth of 20 % in loss was obtained. (4) Resin treatment: A yellow-colored cotton cloth of 150 g/m² in weight was once dipped in a mixed treating solution of thermosetting resin of 10 % Sumitex resin NS-19 (trade name: produced by Sumitomo Chemical Industries Co., Ltd.), 3 % Accelerator X-80 (same as above). 0.1 % Accelerator X-100B (same as above) and 0.5 % Silicon softener N85 (trade name: produced by Matsumoto Yushi Co., Ltd.), then was once squeezed at the squeezing percentage of 80%. The wet cloth was laid over between the two electrode rollers 10, 12 illustrated in Figure 2, and a load of 100 g was applied to both ends of the cloth. When applying 120 V for 20 seconds from the DC power supply 14 while keeping the loaded state, temperature of the cloth was raised to 90°C. After drying the cloth at 120°C for 2 minutes, the cloth was subjected to heat treatment by heating at 140°C for 3 minutes. Thus, a treated cloth of less surface resin and well elastic return was obtained.

Claims: Method for treating a cloth (16) with a treating substance (22) by wetting the cloth (16) with the treating substance (22), squeezing the wetted cloth (16) and heating of the cloth (16) using electrode rolls (10, 12), characterised in that a plurality of anode side electrode rolls (10a to 10n) are horizontally disposed in a treating chamber (28) at the upper portion with a certain distance between one and the other in such a manner as to be opposed respectively to each portion located between one and the other of a plurality of cathode side electrode rolls (12a to 12m), wherein the cloth (16) guided into the treating chamber (28) is alternately wound round the anode side electrode rolls (10a to 10n) and the cathode side electrode rolls (12a to 12m).

Inventors: IWAMI HIDEO, IWAMI, HIDEO
Applicants: NAIGAI TOKUSHU SENKO KK, NAIGAI SPECIAL DYEING CO., LTD.
Application year: 1989
Main classification: D06P5
IPC codes: D06B23, D06P5, D06C7, D06M10