Leather

Abstract Tanning and manufacture of leather utilize both natural and synthetic specialty chemicals. Chrome tanning of cattle hides is the most predominant method employed in modern tanning facilities, although vegetable tannins are often introduced once the preliminary tanning is accomplished. Tanning not only preserves a skin or hide, it also makes the resulting leather resistant to rewetting and to cracking from flexing. The structure and composition of the hide, together with the intended usage, dictate the appropriate treatment. The stepwise process of leather manufacture, including the processing of raw hides and the chemistry of both chrome tanning and leather dyeing, is discussed. The importance of treatment of tanning wastes is also emphasized.