RU1805133C - Method of leather production - Google Patents

Abstract

SUMMARY OF THE INVENTION: washing and soaking of the leather raw material of elk or deer is carried out for 10-14 hours at a temperature of 23-25 ° C, and is gold-coated with an aqueous solution of calcium hydroxide and sodium sulfide for 14-18 hours at a temperature of 23-25 ° amp; deg C, anesthetization of 4-5 hours at a temperature of 26-28 ° C, and pickling 6-8 hours at a temperature of 16-18 ° C. 2 tab.

Description

The invention relates to light industry and can be used in the leather industry for the production of highly elastic chrome tanned leathers from leather raw materials, mainly with a loose structure of collagen fibers in the dermis, namely elk, deer, etc.

An object of the invention is to provide high-quality elastic leather from leather raw materials with a loose collagen fiber structure.

This is achieved by washing and soaking the leather raw materials for 10-14 hours at a temperature of 23-25 ° C. and holding the sol at the same temperature as an aqueous solution of calcium hydroxide and sodium sulfide for 14-18 hours, then desalinate for 4-5 hours at a temperature of 26-28 ° C, and in the process: pickling is maintained at-. a temperature of 16 - 18 ° C for 6 to 8 hours

Reducing the duration of the washing and soaking process 1 (less than 10 hours) leads to a deterioration in the watering of the raw material and leads to insufficient processing on other processes, the skin is tough and slightly elastic. At temperatures less than 23 ° C, the soaking slows down.

Prolonged soaking leads to a weakening of the facial surface of the skin, if it takes more than 14 hours at the specified temperature range, the strength characteristics of the skin are reduced.

Reducing the duration of the process of deformation of the leather raw materials leads to incomplete hair removal and the formation of a squat, stiffness. At temperatures above 25 ° C, the listed defects are observed.

An increase in the duration of the process of tanning leather raw materials more than 18 hours

WITH

00

about eating

"L

with

GO

leads to weakening of the skin by tearing, stitching of the facial layer of the skin.

The process of desalting the goal must be complete. Reducing the duration of the process leads to incomplete removal of calcium salts from the gol. The finished skin is tough, a cage of the face layer is observed, with the duration of the calf less than 4 hours and the temperature less than 26 °.

An increase in the duration of the desoldering process to 5.5 hours is impractical, since the energy consumption is increased and the rational use of equipment (equipment) is reduced, and it may be possible to exaggerate the skin face.

Reducing the duration of the peeling process leads to incomplete peeling, which entails a deviation from the norm of the tanning process (incomplete staining, low temperature of comparison of pain, skin face tint), which occurs when peeling is less than 6 hours ..

With an increase in time during the pickling process, the quality of the finished product does not deteriorate, but it is not practical, since the energy consumption increases and the processing time of the leather raw materials is longer.

A method for producing skin is as follows.

The tanning raw materials, completed with a production batch, which included skins of the same weight and preservation, weighing 2500-3000 kg, enters the workshop. The party included only skins of Los. The skins are hung on the frames of a sectional drum. Here, a pilot batch of leather raw materials is washed, which lasts 1.5-2 hours at a water temperature of 23-25 ° C, and the liquid coefficient (LC) reaches 6.0.

Further, if the frame section apparatus is improperly rotated at a speed of 1 rpm, the skins are soaked while maintaining the above temperature conditions for 8-12 hours and 3-4 g / l Na2S and 1 g / l sodium fluoride are added to the soaking water. .:

The skinning of the hides is carried out in the same sectional drum with an LC-b in a solution of 15 - 18 g / l Ca (OH) 2 and 6 - 8 g / l while maintaining the temperature regime of 23 - 25 ° C for 14 - 18 hours.

After the zoling, the skins are washed with water for 1 hour and the faces are skinned and skinned in a production line with abundant watering on it. The golly is turned over on a cutting table, weighed, sent for washing in a hanging drum for 1.5 - 2 hours at a water temperature at the beginning

washing 16-18 ° C with a gradual increase to 26-28 ° C.

The process of dehumidification of the skins is carried out in a drum at an LCD of 1.5-2.0, in clean water

ammonium sulfate is metered in the form of 3.0 to 3.5% by weight of gol.

The duration of desalination is 4-5 hours, during which time the jelly is completely desalted, the face layer is clean, the phenolphthalein test is 0 to 100%.

Then, the rinsing is carried out with running water until the alkali content in the washing water is no more than 0.2 g / l.

Pickling is not carried out in the same drum 5 in the following way: with an LCD of 0.8 -1.0, the jelly is treated for 15-20 minutes in a sodium chloride solution (salt consumption is 7% by weight of the salt), and then diluted 1 is poured while the drum : 10 sulfuric acid, consumption

0 acid 0.8 - 1.0% by weight of a gol, the temperature during pickling 16.- 18 ° C, and the duration of the pickling is 6 - 8 hours. The acid content in the spent picel liquid is not more than 0.3 - 0, 4 g / l

5, the pitching of the glycol is complete in dense areas of at least 80%.

Tanning is carried out at the end of the pickling process, it is carried out under the same conditions as in the prototype method, such

In the following way: 1/3 of the solution after pickling is drained and water is added to an FA of 0.8 - 1.0 and the chromium extract is filled in based on Cr2O3 with a basicity of 38 - 42% - 2 - 2.2%. 20 minutes after the start of chromium plating give

5 0.5% sodium dichromate, and after 8-10 hours from the start of tanning, the coloring is checked. When completely dyed, hyposulfite is given into the drum at the rate of 2% by weight of the gol. After 2 hours, an instrumentation test is performed, shrinkage is not allowed, tanning is carried out at a solution temperature of 20-22 ° C.

The experiment was carried out under different technological conditions; changing the temperature and processing time of the leather raw material (see Table 1) significantly influenced the quality parameters of the resulting skin (see Table 2). Ready-made batches of leather (clothing, haberdashery, lining) were tested for tensile strength 10

0 MPa% according to GOST 938.11-69, elongation at stretching 10 MPa%. And the mass fraction of chromium oxide in% is determined according to GOST 938.3-77. Preparation of leather samples for physical and mechanical tests was carried out in accordance with GOST

5 938.12-70.

Prototypes of the obtained leathers (see Table 2) corresponded and exceeded the leather indices for clothes and hats (GOST 1875-83), as well as haberdashery leather (GOST 15091-80).

Example 1. Rinsing and soaking is carried out for 10 hours at a temperature of 23 ° C, the gritting lasted 18 hours at the same temperature | the peeling is not softened, and dehydration is carried out at a temperature of 2 ° C for 5 hours. Subsequent pickling is carried out for 6 hours at a temperature of 18 ° C (see table 1, pr. 1).

The resulting skin corresponds to high quality indicators (see tab. 2, pr. 1).

PRI me R 2. Washing and soaking the wire -j- for 12 hours at a temperature of 24 ° C, ashing for 16 hours at the same temperature, softening the peel is not carried out, and desalting at a temperature of 27 ° C for 4.5 hours. Subsequent pickling for 7 hours at a temperature of 17 ° C (see tab. 1, pr.2).

The resulting skin corresponds to high quality indicators (see tab. 2, pr. 3).

Example 3. Rinsing and soaking is carried out for 14 hours at a temperature of 25 ° C, ashing for 14 hours at the same temperature, softening the peel is not carried out, and gritting at a temperature of 28 ° C is flowing | 4 hours. Subsequent pickling for 8 hours at a temperature of 16 ° C (see Table 1, pr. 3). . .

The resulting skin corresponds to high quality indicators (see tab. 2, pr. 3).

Examples 4 and 5 are carried out according to the prohibitive values of the claimed process parameters (see table 1, ex 4 and 5).

The skin obtained in these examples is of poor quality, which confirms the optimal technological conditions in examples 1,2,3.

Claims (1)

SUMMARY OF THE INVENTION A method for producing leather, comprising washing and soaking leather raw materials, staining with an aqueous solution of calcium hydroxide and sodium sulphide, desalting, pickling and chrome tanning, characterized in that, in order to obtain high-quality elastic leather from leather raw materials with a loose structure of collagen fibers, washing and hardening of leather raw materials is carried out for 10-14 hours at 23 -25 ° C, ashing with an aqueous solution of calcium hydroxide and sodium sulphide is carried out for 14-18 hours at .23-25 ° C, and desalination ix 4 - 5 hours at 26 - 28 ° C, and pickling - for 6 - 8 h pri16-18 ° C. Technological processes and processing parameters of leather raw materials 6 is an example according to an analogous method, leather raw materials with a loose structure of collagen fibers (individual batches of elk and deer) were processed using softening and under the indicated technological conditions. 7 prototype example. Table 1 Comparative table of chemical and physico-mechanical properties of leathers Tab. Itza. 2