METHOD OF PROCESSING FUR SHEEPSKIN Russian patent published in 2002 - IPC

FIELD: leather industry. SUBSTANCE: processing includes: soak and squeezing, two-step defatting with aqueous surfactant solutions and intermediate squeezings, further pickling, tannage, fattening, retannage, neutralization with 25% aqueous ammonia and nonionic surfactant solution, and dyeing in aqueous medium. In the first and second defatting operations, aqueous solutions utilized contain condensation product of flotogoudron or oleic acid with triethanolamine (at molar ratio between 0.8:1 and 1.2:1) as cationic surfactant, anionic surfactant (sulfonol NP-1 or sulfoethoxylate), and nonionic surfactant (OP-10 or neonol). In neutralization nonionic surfactant is the same as in defatting operations. Dyeing is effected with acid dyes in aqueous medium containing above-named condensation product, and 85% formic acid. EFFECT: improved processing quality due to increased degree of cleanliness of haired surface and binding of dye to hair and extended choice of processing reagents. 5 tbl