SU607855A1 - Method of preparing carbon cloth - Google Patents

Description

(54) SPSUOB OF OBTAINING CARBON TISSUE of the structure of the pile and the strength of carbon fabric. This is comprehended by the fact that the fabric on the basis of viscose fiber is impregnated with a solution of a catalyst, the impregnated fabric is dried, subjected to heat treatment (carbonization and graphitization) and then heated up the surface of the heat-treated (graphitized) fabric. Napping the surface of the fabric after its heat treatment to the final temperature (graphitization) significantly reduces the time it takes to dry after impregnation with a catalyst, since fabrics with a smooth surface dry 1,. 0 times faster than similar fabrics with a nap. In addition, in the proposed method, the completed pile is not exposed to any impact prior to the start of fabric operation, is not deformed and does not fall. Due to the greater elastic modulus of carbon fibers compared to the viscose fiber module, the pile has a greater angle of elevation, a more uniform structure and height. In the proposed method, the temperature-temperature processing of the fabric, including graphitization, can be carried out in a continuous pattern with direct current flowing along the fabric, which increases the productivity of the process by a factor of 10-25. The fabrics obtained by the proposed method do not deteriorate their breaking strength after napping to the same extent as those obtained by the azvestnog method. In some cases, the rupture strength of carbon fabric on the base even increases after napping the surface, which can be explained by a decrease in the crimpiness of the base when loosening weft and relieving internal stresses. In order to obtain a carbon fabric under the conditions of the proposed method, any catalysts used in the technique are applicable, for example, (KNch) 2HPO, CNHi,) H2PQ4 as well as mixtures thereof. From the composition of the catalysts, except for CHS, the most effective is the mixture (KHZ) 2НРО |, $ NH2) 2COr. This component is taken in a 4: 1 ratio. Aqueous tests of catalysts were tested, although acetone, ethyl alcohol, and ethers can be used as solvents. The best effect is achieved when catalysts are introduced from solutions that are sprayed at normal temperature, although it is possible to obtain fabric and impregnate it with solutions with a concentration of 25–200 g / l. The effect of the presence of catalysts appears when the salt is in weight after drying from 0.5-1.0 wt. % However, the introduction of an excess of catalyst into the fabric is technologically justified. The best rezuligaty during heat treatment of the fabric is achieved in the proposed method with a catalyst gain of 20-35%. Example. Viscose twill fabric, made on the basis of cord threads No. 5.45, and on duck from staple threads 40/2, is impregnated at 2 ° C in a continuous solution of chemically pure ammonium chloride in distilled water with continuous tissue 1m. . Cloth time in the bath 10 min. After free draining of the solution from a vertically mixed fabric, it is dried in a continuous dryer at a temperature of 140 ° C to 20 ° C. The air heated in the electric air heater is used as a drying agent. The time required for viewing to a moisture content of not more than 6% by weight is 30 minutes. After drying, the fabric impregnated with ammonium chloride is subjected to heat treatment (carbonization and graphitization) with a total duration of about 2 minutes to a temperature of 2600 ° C in a continuous-action furnace with a slit heater. The heat treatment of the fabric is different. In one case, the heating of the fabric is carried out in a nitrogen atmosphere at a rate of 1300-15OO deg / min to the final temperature. The resulting fabric has some soot on the surface. In the second case, the heating of the fabric to the temperature ZrO ° C is carried out in air for O, 8-1, O min, and then heated to 2600 ° C in a nitrogen atmosphere. The rate of heating in air is 29 ° 32 ° C / min, while in nitrogen it is –2500–26 ° C / min. The resulting fabric has a clean silver surface, the Graphite fabric is placed on. The feeding drum and secured by a sliding mechanism. In the process of rewinding the fabric, rotating cylindrical rods are applied to its upper surface. The rotation speed of the brush is 5 rev / sec. The movement speed of the fabric with respect to the web is 25 m / h. After the brush is rotated on the surface of the fabric, the thief is 3 ksh in length, and the strength of the cloth polish 5 cm wide to the pile and after pile is 6.6 kg and 6.05 kg, respectively.

When processing on the same equipment of the same fabric with a pre-articulated burr, the time required for the view of the impregnated fabric to a moisture content of 6 wt. % is 6 O-7 O min.

After graphitization, the pile has a convoluted structure, the length of the pile varies from 0.5 to 5 mm in the presence of areas of close fit to the base. The strength of a strip of fabric 5 cm wide after graphitization is 2.7-3.8 kg.

Specifications

Known method

Time-Drying Soaked

6O-70 min catalyst cloth

Strength of a strip of fabric 5 mm wide (with nap) after graphitization

2.7-3.8 kg

The composition of the pile

Twisted, of different lengths, with areas of tight fit to the base

Total process time

9.5-13.5 hour

Claims (1)

Invention Formula The method of obtaining carbon fabric from the fabric based on viscose fiber, including napping the surface of the fabric, impregnating the fabric with a solution of catalyst, drying The table presents comparative data characterizing the known and proposed methods. As can be seen from the table, the proposed method for producing carbon fabric with a naped surface makes it possible to more than double its production time and improve quality. The nap of the fabric can also be carried out at lower final temperatures of processing the fabric. Present method ZO min 6.05 kg Straight, of equal length, uniform distribution 40-5O min - V impregnated fabric and subsequent heat treatment, characterized in that, in order to intensify the process, increase the uniformity of the pile structure and the strength of the carbon fabric, napping is performed after heat treatment.