METHOD FOR PRODUCTION OF LEATHER SEMI-PRODUCT OF ALL TYPES OF FRESHWATER FISH Russian patent published in 2019 - IPC C14C1/00 C14C13/00 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to fish-processing industry, namely to non-waste technology of processing secondary products of cutting freshwater fish to produce tanned leather semi-finished product. Method of producing a leather semi-product of all types of fres-hwater fish skins involves soaking fish skins in solution containing 4.5–5.0 wt% sodium chloride and 0.1 wt% antiseptic at temperature of 18–20 °C for 4.0–6.0 h, degreasing by treatment with 0.8–1.0 % soap solution for 1.5–2.0 hours at temperature of 37–40 °C and with periodic mixing. Then, removal of scales is performed by treatment with 0.2–0.5 % solution of protease enzyme preparation for 6.0–8.0 h at temperature of 37–40 °C and with periodic mixing, after that skins are thoroughly washed with cold water. Then one performs scouring, pickling by treating skins with solution containing 6 % glacial acetic acid and 3–3.5 % of food culinary salt to the solution weight for 8–12 hours at temperature of 18–20 °C, followed by tanning, fragrance , drying and storing the obtained semi-product.

EFFECT: proposed method for production of tanned semi-product of all types of freshwater fish skins allows to produce tanned semi-product of high quality, to realize non-waste technology of processing of secondary products of freshwater fish cutting, to rationally use leather raw material of fish industry, which is not in demand for technical purposes, reduced duration of technological process of production of tanned semi-product from skins of all types of freshwater fishes as compared to prototype from 66–54 hours to 41½–54 hours, enhance environmental friendliness of the process.

1 cl, 1 dwg, 3 ex