GB1275889A - Depilatory process - Google Patents

Abstract

1275889 Depilating skins J H HOWE 6 May 1971 [29 March 1971] 13489/71 Heading C6C Treatment of sheepskins to enable the wool to be removed freely, e.g. by hand, comprises immersing the skins in unheated circulating water, e.g. between 35‹ and 75‹F., adding an acid to the water to bring the pH to a value of from 1.5 to 2‹5, preferably 1À6 to 1.8, maintaining the pH at this value until the skins become "plumped", and then slowly increasing the pH to a value of from 3.5 to 5.0, preferably 4.3 to 4‹5. After a period e.g 2 hours, at this value the skins are held for a period of 18 to 20 hours at a temperature of 80‹ to 100‹F., preferably 90‹ to 95‹F., by either heating the water or removing the skins from the water, squeezing them, and hanging them in a room in which heated air is circulated. The acid added to the water may be a mineral acid such as sulphuric, nitric, hydrochloric or sulphurous, or a mixture of acetic acid and a mineral acid. The increase of pH value to 3.5 to 5À0, preferably over a 2 hour period, is effected by the addition of any suitable alkaline substance, from a strong alkali such as sodium hydroxide to a mildly alkaline salt such as sodium acetate.