SU1608223A1 - Method of producing leather for shoe uppers - Google Patents

Abstract

The invention relates to the leather industry and improves the quality of leather and saves chemical materials. The tanned semi-finished product after two-phase tanning is washed with an HC of 1.2-1.4, the initial temperature is 30-40 ° C with a gradual increase to 60-65 ° C for 30-40 minutes. Upon completion of washing, the process of retanning - filling with tanning agent, dicyandiamide modified product of hydrolysis of leather shavings with LC 1.5-2.0, temperature 60-65 ° C, duration 1.0-1.5 hours, consumption of tanning agents 3-4% from the mass of planed leather. This is followed by neutralization at a consumption of sodium bicarbonate of 1.9-2.1%, dyeing and greasing. The dye consumption is reduced by 40-50%, fattening mixture - by 12.5-25%. 2 hp f-ly, 2 tab.

Description

The invention relates to leather industry and can be used in the manufacture of leather for upper shoes.

The purpose of the invention is to improve the quality of leather and the economy of chemicals.

The essence of the invention is that the retanning-filling of the leather is carried out before neutralization with a dicyandiamide tanning agent modified by the products of the hydrolysis of leather shavings.

The method proceeds as follows.

The semi-skins mock-salted batch of canning at the stage of washing, soaking, dehairing, ashing, washing, desalting, -i softening, washing, pickling, tanning of the I phase, laying, pressing, gouging are processed in accordance with the known method. Then, the second phase of tanning is carried out in a drum in an aqueous solution with an LC of 1.2-1.4, a temperature of 35-40 ° C and the following consumption of components,% by weight of sliced leather: chrome tanning agent with a basicity of 38-42% 1.1-1, four%; sodium bicarbonate

O5

00 t N3

ss

0.5-0.8. Water is poured in (AZ-ZO S), chrome tanning agent is dosed, rotated for 10 minutes and chrome planed semi-finished product is loaded. Rotation is 2 hours, after which sodium bicarbonate solution is fed to 2 doses, then washing is carried out at the LCD 1.2-1.4 and the initial temperature is 30-40 °; gradual increase to 60-63 ° C for 30-40 minutes. At the end of the flushing process, the process of retanning-filling with DDM11GKS tanning agent in a drum in an aqueous solution with an LCD of 1.3-2.0, a temperature of 0–1.3 h and a tanning consumption of 3-4% by weight is carried out. planed leather. This is followed by neutralization at a consumption of sodium bicarbonate of 1.9-2.1%, washing, dyeing, greasing, washing and decay, and all subsequent events in accordance with the indicated method, with the exception of reducing the consumption of dye by 40-30% and the consumption of fattening mixture by 12.3–23%, and also exclude completely the process of retanning by organic tannins. All subsequent operations are also carried out in accordance with the indicated methodology.

Examples of the method are given in table. one.

An example (comparative). They take the batch of wet-salted preservation after washing, soaking, dehairing, ashing, washing, desalting, softening, washing, pickling, tanning, phase I, washing, pressing and gouging and taking the second tanning phase with LC 1.2-1, 4, at a temperature of 35-40 ° C for 3 hours and with a consumption of chrome tanning of 1.8-2.0% (basicity of 38-42%) and sodium bicarbonate 0.3-0.8%. This is followed by washing, neutralizing, washing, dyeing, greasing and retanning

nical tanning agents at K 1, -2, and for 1.3-2.0 hours at 34-40 s. Consumption of dubitel 2-3%, counting on dubitel.

Quality indicators obtained leather are given in table. 2

As can be seen from the table. 1 and 2, the method allows to obtain a semi-finished product of good quality. The following indicators are improved compared with the prototype: the tensile strength of the skin is increased by 1.3 times, the stress at the occurrence of cracks; the face layer is 1.3 times, the elongation at standard load is 1.2 times the chromium content semi-finished product - 1.2 times.

Claims (3)

1. A method of wearing leathers for upper shoes, including two-phase tanning of a semi-finished product in an aqueous solution of tanning chromium compounds, washing, neutralization, dyeing, fattening and double-filling, in order to improve the quality of leather and save chemical materials , retanning-filling is carried out before neutralization with a dicyandiamide tanning agent modified by hydrolysis products of leather shavings. 2. A method according to claim 1, characterized in that the retanning-filling is carried out at a temperature of 60-63 ° C for 1.0-1.3 hours at a consumption rate of 3-4% by weight of the shaved leather. 3. The method according to claim 1, characterized in that the washing of the semi-finished product after tanning is carried out with a gradual increase in temperature from 30-40 ° C to 60-63 ° C over a period of 30-40 minutes. Reagents and process parameters T a b j and p a Example 2I 3 IIZI 1.1 1.2 1.4 3, 0 3.5 4.0 0.5 0.55 0.6 0.25 0.27 0.3 6, 0 6.5 7.0 60 70 75 1.0 1.25 1.5 30 40 35 30 40 35 62 65 60 Temperature of welding, with oxide content chromium in the skin,% Content of substances extracted by organic solvents,% Strength at tensile strength, 9.8 MPa Stress at appearance front layer cracks, 9.8 MP Elongation at a voltage of 9.8 MPa,% T a b l n C a 04 5.0 8.4 2.0 1.3 1.4 5 106 106 5.5 5.8 9.2 .2,3 1.4 1.6 38 9.8 2.2 1.4 1.7 38