RU2460805C1 - Method of processing natural leather with grain breaks - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: proposed method comprises subjecting natural leather to low-temperature plasma of high-frequency induction discharge for 30-120 seconds at discharge chamber pressure of 40-60 Pa at flow rate of plasma-forming argon of 0.04-0.08 g/s at current of 0.3-0.9 A. Then, it is subjected to low-temperature plasma of high-frequency induction discharge for 60-600 seconds at discharge chamber pressure of 13.3-26.6 Pa at flow rate of plasma-forming argon of 0.02-0.06 g/s at current of 0.3-0.7 A and voltage of 1.3-3.0 kV.

EFFECT: ruled out grain breaks.

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Description

The invention relates to the leather industry and can be used in the decoration of genuine leather having a raw and technological defect - perfume, in particular in the manufacture of genuine leather for upper shoes.

The perfection is manifested as a lag of the papillary layer from the reticular layer in the form of deep, non-smoothing wrinkles that form on the front surface of the skin when it is bent inward and does not disappear after straightening the skin. This defect may occur as a result of improper technological processes of skin production, violations of chemical and physico-chemical processes, as well as mechanical operations. If the defect is detected in the finished skin, then its grade is reduced, in the future such skin is used to manufacture products of lower quality.

It is known that treatment of genuine leather with low-temperature plasma leads to an improvement in the quality of the skin and an increase in its physical and mechanical properties (Pat. RF No. 2127763, MPK ⁷ C14C 9/00, 11/00, B29C 59/14, 1999; Pat. RF No. 2298040, MPK ⁷ C14C 9/00, C14C 11/00, 2007). Known methods are the impact of low-temperature non-equilibrium plasma high-frequency discharge on natural skin in order to improve quality, increase coating adhesion and increase the strength characteristics of chrome tanned leathers.

However, these methods are not used to treat skin with a defect in perfume, and using them to treat genuine leather with the specified defect does not eliminate it.

Ways to finish genuine leather, eliminating the defect of the perfume of leather, have not been found in information sources.

The objective of the invention is the elimination of the defect of perfume of genuine leather.

The objective is achieved in that in a method for treating genuine leather with a defect of perfume, natural skin is exposed to a low-temperature plasma of a high-frequency (HF) induction discharge for 30-120 seconds at a pressure in the discharge chamber of 40-60 Pa with a flow rate of a plasma-forming argon gas of 0.04-0 , 08 g / s at a current strength of 0.3-0.9 A, then subjected to low-temperature plasma high-frequency capacitive discharge for 60-600 seconds at a pressure in the discharge chamber of 13.3-26.6 Pa with a flow of plasma-forming argon gas 0 , 02-0.06 g / s at s le current voltage of 0.3-0.7 A and 1.0-3.0 kV.

When processing the leather for the upper of shoes, introduced into the plasma of a high-frequency discharge, acquires a negative potential relative to the plasma itself and is subjected to ion bombardment by a plasma-forming gas argon. Ions, falling on the surface of the skin, recombine. Under the influence of electrostatic fields, the fibers of natural leather for the upper of the shoes are redistributed in the internal volume, which leads to modification of the properties of the skin and its outer surface.

Three processes make the greatest contribution to the modification of the external surface of the skin: the recombination of ions and the transfer of energy acquired in the surface charge layer at the surface of a solid body, thermal action, and the “bulk” modification - ion recombination. The heat flux density does not exceed 8 · 10 ³ W / m ² .

The method is carried out on high-frequency induction and high-frequency capacitive plasma systems in stages.

The first stage of processing takes place on a high-frequency induction (RFI) installation (Fig. 1), containing a mechanical pumping system 1, power supply system 2, gas supply system 3, water supply system 4, generator 5, diagnostic system 6, vacuum chamber 7, inductor 8.

The first step of the method is as follows. In the vacuum chamber 7, genuine leather is mounted above the inductor 8 perpendicular to the plasma-forming gas flow. Air is pumped out and working gas is introduced into the vacuum chamber 7. Set the desired pressure. When 8 rf voltage is applied to the inductor 8, a plasma clot forms in the vacuum chamber, and when blown through it, the plasma-forming gas forms a plasma jet - a processing tool.

The plasma treatment mode is regulated when exposed to low-temperature plasma of a high-frequency induction discharge by changing the plasma exposure time of 30-120 seconds, the pressure in the discharge chamber of 40-60 Pa, the flow rate of argon plasma-forming gas 0.04-0.08 g / s, current 0.3 -0.9 A.

The second stage of the method is carried out on a high-frequency capacitive (VCHE) installation (Fig. 2), containing a drum 1, high-frequency electrodes 2, a cap of a vacuum chamber 3, a console for opening the cover of a vacuum chamber 4, a vacuum chamber 5, a plasma gas supply and adjustment system 6 , HF generator 7, vacuum pumping station 8.

The second step of the method is as follows. In the vacuum chamber 5, genuine leather for the upper of the shoes is installed in the gap between parallel vertically arranged electrodes 2 in the path of the plasma gas flow. Air is pumped out of the vacuum chamber and the working gas is injected, setting a predetermined pressure. When high-frequency voltage is applied to the electrodes 2 in the discharge chamber 6 due to heating of the plasma-forming gas to the plasma state, a plasma flow is formed - a processing tool.

When exposed to a low-temperature plasma of a high-frequency capacitive discharge, the plasma treatment mode is controlled by changing the plasma exposure time of 60-600 seconds, the pressure in the discharge chamber 13.3-26.6Pa, the flow rate of a plasma-forming argon gas 0.02-0.06 g / s, current 0.3-0.7 A and voltages 1.0-3.0 kV.

The invention is illustrated by the following examples of specific performance.

Example 1

A sample of chrome-tanned cattle genuine leather (RED) is installed in the discharge chamber of an RFI discharge and is treated with low-temperature plasma with the following parameters: plasma exposure time of 30 seconds, pressure in the discharge chamber of 60 Pa, argon plasma-forming gas flow rate of 0.06 g / s, current strength 0.7 A.

Then, the sample is reinstalled into the discharge chamber of the HF discharge and the treatment is performed with the following parameters: plasma exposure time of 600 seconds, pressure in the discharge chamber of 26.6 Pa, argon plasma-forming gas flow rate of 0.04 g / s, current strength 0.3 A, and voltage 1 , 5 kV.

Example 2

Similar to example 1, but the process is carried out with the following parameters:

- for RFI discharge - the plasma exposure time is 45 seconds, the pressure in the discharge chamber is 50 Pa, the flow rate of the plasma-forming argon gas is 0.08 g / s, the current strength is 0.8 A;

- for RFID discharge, the plasma exposure time is 500 seconds, the pressure in the discharge chamber is 26.6 Pa, the flow rate of the plasma-forming argon gas is 0.04 g / s, the current strength is 0.4 A, and the voltage is 1.3 kV.

Example 3

Similar to example 1, but the process is carried out with the following parameters:

- for RFI discharge - the plasma exposure time is 60 seconds, the pressure in the discharge chamber is 40 Pa, the flow rate of the plasma-forming argon gas is 0.04 g / s, the current strength is 0.6 A;

- for RFID discharge, the plasma exposure time is 180 seconds, the pressure in the discharge chamber is 26.6 Pa, the flow rate of the plasma-forming argon gas is 0.04 g / s, the current strength is 0.5 A, and the voltage is 1.7 kV.

Tests of the processed samples of natural leather of cattle of chrome tanning for perfume were carried out in accordance with GOST 938.31-78. As the main technological properties selected physico-mechanical properties of the skin.

The tensile breaking load was determined according to GOST 938.11-69. The resistance of the coating to the skin to repeated bending was determined according to GOST 13868-74. The adhesion of the coating was determined according to GOST 939-88. Note 6 "Method for determining the adhesion of emulsion and nitroemulsion coatings to the skin." The welding temperature was determined according to GOST 938.25-73.

The test results of samples of genuine leather for shoes with defectiveness of breathability after the proposed processing method are shown in the table.

An analysis of the data presented in the table shows that the proposed method for treating genuine leather with a defect of perfume eliminates this defect, while increasing the stability of the coating, the strength of the skin, and the adhesion of the coating. The welding temperature remains almost unchanged, which is an indicator of the stability of the internal structure of the skin.

Samples The presence of a defect in suffocation Physical and mechanical properties Coating stability, number of bends Tensile load, 10 MPa Welding Temperature ° C Adhesion to dry skin, N / m No processing there is 39,000 20.5 107 400 Example 1 no 43000 29.4 108 850 Example 2 no 41000 25.3 108 680 Example 3 no 39,000 22.7 107 470

The use of the present invention eliminates the defect of perfume and at the same time improves the physical and mechanical properties of natural leather for upper shoes.

Claims (1)

A method for treating genuine leather with a defectiveness of perfume, characterized in that the natural skin is exposed to low-temperature plasma of a high-frequency induction discharge for 30-120 s at a pressure in the discharge chamber of 40-60 Pa with a flow rate of a plasma-forming argon gas of 0.04-0.08 g / s at a current strength of 0.3-0.9 A, then subjected to low-temperature plasma high-frequency capacitive discharge for 60-600 s at a pressure in the discharge chamber of 13.3-26.6 Pa with a flow rate of a plasma-forming argon gas of 0.02-0 , 06 g / s at a current strength of 0.3-0.7 A and n stresses 1.0-3.0 kV.

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