SU23539A1 - The method of tanning hides - Google Patents

Description

- The proposed method of tanning hides, which is partly a picky way, aims to make it possible to use a pickle with a low content of free acid, to give it tanning properties and to avoid the harmful effect of a more concentrated mineral acid on skin strength, and also 8 ways to achieve new effects.

Plant material, namely: sawdust, tree bark, seed shells, peat, straw, etc., are exposed when heated with sulfuric or hydrochloric acid, in the presence of sulfuric acid or sodium chloride and the resulting solution of oak t hide. For example, they take 1000 g of pine sawdust, mix with 2000 t of table salt, pour a cub. cm diluted hydrochloric acid, diluted in 600 cubic meters. cm of water and heated, for example, in a flask with a reflux condenser at a temperature of 130-140 for about two hours, after which water is added to 20 liters and heated again in the same way; after cooling, it is filtered through glass wool and some soda is added so that the free acid remains at about half percent. The skin prepared in the usual manner for tanning is put in the resulting solution (for example, for a sacking for 1-2 hours) and.

by wringing, dried and diluted. To enhance the tanning effect of the solution, it is useful to add 5-101 sulfur and 10-20 i carbolic acid or naphthalene to the mixture of sawdust and salt before heating.

Leather obtained by the described method, receives the properties of half-suede. Dried and diluted, smeared with fish oil, even without a shaft or in a drum and without heating, after a few hours of ventilation, it does not lose its properties when washed with a solution of soap and soda in hot water, and in the skin with hair suede and hyaline, The papillary layer is usually removed during suede because of the difficulty in soaking them with fat. For impregnation, fat may be taken, dissolved, for example, in gasoline (one part fat per ten parts gasoline); the solvent may be distilled off for later use. Fat can also be replaced in part by mineral, spun oil treated with air blowing. To obtain a more waterproof skin, the latter is further processed as follows: it is dipped into a bath with an aqueous solution of aluminum salt, to which alkali is added to form an aluminum oxide hydrate suspended in a liquid, or the skin is first impregnated

dusty f acTBOpOM, and then a solution of a salt of a heavy metal.

The proposed method without fattening and without treatment for water permeability by insoluble precipitates serves as a good dubbing for chrome tanning; the skin is quickly blown out in a very weak solution of chromic alum, to which sedy,

The subject matter of the invention.

1. A method of tanning hides, characterized in that the material of vegetable origin, such as: sawdust, bark, seeds, straw, peat, etc., is exposed when heated at 25-4Q ° / o sulfuric or salty acids in the presence of sulphate or sodium chloride, reduce the acid concentration by topping up with water; to 1-1 V2% free acid and, after averaging soda to a weak acidity, oak obtained solution of the skin.

2. Alteration of the process indicated in claim 1, characterized in that a small amount of sulfur and phenol or naphthalene are added with the acid.

3.Application at specified in clauses. 1-2 of the method of subsequent fattening with fat dissolved in petroleum hydrocarbons.

4 .. Application at specified in pp 1-3 of the method of subsequent treatment with a suspension in water of insoluble soaps or aluminum oxide hydrate.

5. The use of the method specified in p. P. 1-2 as a zadubka with chromel tanning.