Method of finishing
(57) Abstract:The method refers to the leather industry and is used for finishing of chrome leather. The technical result of the invention is to improve the quality and adhesion of the coating of chrome leather. Before applying the first coat coating paint the skin is exposed to low-temperature nonequilibrium plasma of high-frequency discharge in a vacuum chamber within 300-600 C. Exposure is carried out at a pressure in the chamber 53,3-80 PA and the flow rate of plasma-generating air-0.04-0.06 g/S. the strength of the current at the anode generator lamp 0,2-0,6 A. Then perform successive application of several layers of coating paint on the skin. 1 table, 1 Il. The invention relates to the leather industry and can be used for finishing of chrome leather.There is a method of finishing of natural leather the introduction of a sealing primer and top coat paint for finishing leather copolymer, dehydrophenylalanine N-methylolmethacrylamide (see for example A. with. 1420022).The disadvantage of this method of finishing is the use of additional chemicals and toxic solvents.There is a method of finishing by establishing 8-8,5 G (see for example and.with. 1234434).The disadvantage of this method is a slight increase adhesion of the coating to wet the skin.The closest in technical essence and the achieved result is a way of finishing chrome-tanned leather, which is carried out by applying non-pigmented soil, pressing with a hydraulic press, and then applied three coats of finishing paint and hardener, the skin is pressed and dried (method of generation of leather, chrome tanning of different thicknesses and range for the uppers, ZNIIK, M., 1991).The disadvantage of this method is the small depth of dye penetration and low adhesive properties.The objective of the invention is to improve the quality and adhesion of the coating of chrome leather.This object is achieved in that a method of finishing of chrome leather includes a serial applying multiple layers of coating paint on the skin, before applying the first coat coating paint the skin is exposed to low-temperature nonequilibrium plasma of high-frequency discharge in a vacuum chamber at a pressure of 53.3 per - 80,0 PA, for 300 - 600 s, the plasma gas flow of air 0,04 - 0,06 g/s, the current at the anode generator lamp 0,2 - 0,6 A.
SMI and bombarded with ions of the plasma gas. However, getting on the surface of the skin, they give her his excitement. Because plasma ions at the surface of the skin have an energy of 90 eV, then realized the process of ion bombardment leads to modification of the surface layer due to surface cleaning - spraying and loosening of the material (depth modification 200-250 microns).When applying the first layer coating paint on the skin after exposure to low-temperature nonequilibrium plasma of high-frequency discharge, dye molecules easily penetrate into cleansed from dirt and loosened the surface, because the particles of the foaming agent receive additional penetration into the pores of the skin surface and rendezvous with the reactive functional groups of macromolecules leather. Thus, the increased depth of penetration of the coating paint and improves the adhesion of the coating to wet and dry skin.The method is carried out on the plasma installing RF. Installation (Fig. 1) contains a high-frequency (HF) generator (1), torch (2), the inductor (4), vacuum chamber (3), the gas supply system (5), the pumping system (6), measuring devices (7).The method is as follows: the skin POM washed the entire surface. Processing is done on the front side, Is evacuated from the vacuum chamber (3), then putting a working gas control valve connecting the vacuum chamber with mechanical pumps, the pumping system (6), set point pressure, is included RF generator (1), the oscillator frequency of 1.76 MHz.Under the action of electromagnetic fields is heated plasma gas to a plasma. Mode plasma processing is controlled by changing the current for generating the lamp of 0.2 - 0.6 A, the pressure in the discharge chamber 53,3 - 80 PA, the flow rate of plasma-generating air-0.04 - 0.06 g/s and time of exposure to plasma of 300 to 600 C.The research results of the proposed method of finishing and indicators of physical and mechanical properties are shown in table 1. Data analysis the table shows that the method of finishing due to the impact of low-temperature nonequilibrium plasma of high-frequency discharge before applying the first coat coating paint allows you improve the quality of the coating by increasing the depth of penetration of the dye and the adhesion of the coating dyeing without compromising strength. The optimal mode for finishing are the influence of the current on the anode generator lamp 0,2 - of 0.6 A. the Method of finishing outside the boundaries of these values leads to deterioration by decreasing the depth of penetration of the dye, the adhesion of the coating, and hence the stability of the coating to repeated bending.The adhesion of the coating is determined according to GOST 939-88, note 6 "Method of determining the adhesion of the emulsion and microemulsion coating to the skin."The depth of penetration of the dye was determined by scanning electron microscope SET-202M in the laboratory methods of the workshop on the chemistry and technology of leather and fur authors A. A. Golovteev, D. A. Kutigi, L. B. Sankin, M. , Legprombytizdat, 1987, pp. 250-258.The stability of the coating on the skin to repeated bending is determined according to GOST 138-68.Breaking load tensile determined according to GOST 938.11-69.The advantage of this method compared to the prototype are:
- improving coating adhesion to dry and wet skin;
- increase the depth of penetration of the dye;
- resistant coating to repeated bending;
- the improvement of working conditions at the expense of ecological purity of production;
the exception is in the final stages of finishing the use of toxic and flammable organic is ukryvnoy paint on the skin, characterized in that before applying the first coat coating paint the skin is exposed to low-temperature nonequilibrium plasma of high-frequency discharge in a vacuum chamber within 300-600 s, when the pressure in the chamber 53,3-80,0 PA and the flow rate of plasma-generating air-0.04-0.06 g/s, while the current in the anode generator lamp of 0.2-0.6 A.
FIELD: process engineering.
SUBSTANCE: proposed invention relates to surface processing of certain areas in composite material structure. Processing is conducted by, at least, one plasma beam at atmospheric pressure, said beam being produced by plasma generator furnished with emission nozzle to facilitate adhesion binding with the other structure. Plasma beam sent through the nozzle comprises active gas projected onto composite material structure from the distance varying from 0.2 to 10 cm and at incidence angle varying from 75° to 105°. Note here that plasma beam is directed so that the angle of contact with composite material structure makes less than 90°. Note here that composite material structure wets the surface of another structure. Note also that the angle of contact represents an indicator of efficiency of structures adhesion binding.
EFFECT: higher reproducibility and reliability, lower costs.
11 cl, 6 dwg