SU67106A1 - Tanning method - Google Patents

Description

To reduce the consumption of tannins and speed up the tanning process, the authors propose a "dry method of tanning the skin with vegetable tanning agents without pretreatment of the needles of chromic juices.

The proposed method consists in the fact that normally prepared hide, completely deashed, pierced and pressed, is treated in the drum with a concentrated solution: ha of sulfitized vegetable tanning extracts with a low liquid coefficient. The consumption of tannins at this is equal to 18–20% of the weight of the non-ash-free mole, which is about 65% of the norms of standard production methods. Tanning lasts 18-20 hours, after which the skin is completely dyed with tannins.

Approximate skin treatment method (stelechnoy).

I. Preparatory operations are carried out in the usual manner. The sludge is spent in vats, the duration of soaking is 48 hours. On the second day, raw materials are sold throughout the year.

square and load on fresh water. Raw materials should be well soaked. The recovery is carried out according to the system of three vats: old, medium and fresh ash pits; Ashes duration -6 working days. The hide is doubled for the thickness of the facial splice-4.0-4.2 mm. ,

2. Golya is decapitated with ammonium sulphate; Desalting should be complete.

3. The pnkel is held in the outboard drum at an 0.9–1.0 liquid ratio. The composition of the bath: sulfuric acid 7-8 g / l or equivalent amount of hydrochloric acid; salt 60-70 g / l; temperature 16-18 ° C; the duration of pickling is 4, 5 hours, the pH of the cycled mole is 4.5-4.8. Pickled hide is unloaded and lined on shelves for daily laying, after which it is pressed, cut into halves and set into "dry tanning."

4. For tanning a pickled scotch, extract the extract (oak or mixture of oak with various plant extracts) with the addition of phenolic sulfite in the amount of 4% by weight of the dry extract. The density of the boiled extract is 20-22 ° Be.

An extract is poured into the tanning drum at the rate of 18-20% of tannids based on the weight of the non-ash-free gee. Liquid coefficient set 0,70-0,75.

The duration of tanning is 18-20 hours, while the direction of rotation of the drum changes every 30 minutes. The initial tanning temperature is 20 °. The temperature during tanning should not exceed 40 °. In the case of a temperature rise above 40 °, the drum is stopped And the lid is opened.

The drum is loaded with 500 kg gol in the bat; I eat the volume of the drum 11 iM.

The skin after tanning should be completely stained with tannins.

Unloaded skin receive. daily laying, then deoxidation in vats in a hinge on the poles during the day. After deoxidation, the skin is pressed to a moisture content of 45-50% and grilled in a drum using the usual method.

5. Plating, drying and finishing operations are carried out in the usual manner.

Subject invention

The method of tanning with vegetable tanning agents, characterized in that the ashless pickled peel after pressing is pressed, then treated with a sulfitated solution of vegetable tanning with a density of 20-22 ° Vy at a liquid coefficient of 0.70-0.75.