Treatment of fat

Lipases offer the tanner two advantages over solvents or surfactants: fat disper­sion and production of waterproof and low-fogging leathers. Alkaline lipases are applied during soaking and/or lim­ing, preferably in combination with the relevant protease. Among other things, the protease opens up the membranes surrounding the fat cell, making the fat accessible to the lipase. The fat becomes more mobile and the breakdown products emulsify the intact fat, which then distributes itself throughout the pelt so that in many cases a proper degreasing with surfactants is not nec­essary. This facilitates the production of waterproof and low-fogging stock. Lipases (acid) can also be applied in an acid process, e.g. for pickled skin or wool-on and fur, or semi-acid for wetblue.