METHOD FOR TREATMENT OF LEATHER RAW MATERIALS Russian patent published in 1995 - IPC

FIELD: leather production. SUBSTANCE: washed leather raw materials are wetted in aqueous solution of sodium carbonate and alkali protease. Then treatment in aqueous solution of sodium sulfide takes place within 30-40 min, expense of said solution being 0.7-0.8 % of raw materials mass, liquid coefficient being 0.5-0.6. The process is followed by liming in the same bath within 50-60 min in aqueous solution of calcium hydroxide and sodium sulfide, its expense being 0.5-0.8 % of raw materials mass. Then liming within 7-8 h at liquid coefficient 0.7-0.8 followed by washing and final liming is carried out. EFFECT: improves efficiency of the method. 1 tbl