SU145299A1 - The method of preparation of wood to obtain tanning extract - Google Patents

Description

The known methods of preparing wood for producing a tan extract are either grinding wood on chippers into cubes with a side size of 20 to 5 mm, or wood flour is used for this purpose.

Next comes the process of extracting the tannides from the ground material.

The main disadvantages of the first method are the large loss of tannides in dupin (up to 1%) with 4-5% of them in the starting material and the duration of the extraction time.

When extracting the tannides from wood flour, the gruel of the latter, obtained when mixed with the solvent, clogs the diffusers, which makes the existing extraction equipment unsuitable.

A method for the preparation of wood to produce a tanning extract is proposed, which consists in that the wood particles (oak sawdust or chips) are treated on a five-roll roller mill VS-5 through all four passes.

As a result of processing, petals are obtained with a thickness of from 0.1 to 0.4 mm. According to the authors, as a result of this treatment, deformation of cellulose and redistribution of tandides from cells and intercellular passages to the surface of the lobe occurs, which leads to increased contact with the solvent and, consequently, to a greater degree of extraction of tandides and acceleration of the extraction process.

Extraction of the tannides is carried out on existing equipment.

No. 145299-2. The test of the samples obtained by the proposed method for extracting tandides from them under production conditions showed that the residue of tandides in dubin is 0.2-0.33% and in the grinding shop 0.67-1.0 % with equal extraction conditions.

Subject invention

The method of preparation of wood to obtain tanning extract, using oak sawdust or shavings, characterized in that, in order to increase the yield of tanning tannides, oak sawdust or shavings, it is pre-extracted before being extracted on a sawing machine.