GB409916A - Improvements in or relating to the treatment of pile fabrics - Google Patents

Abstract

In the treatment of fabrics having a pile consisting of or containing organic derivatives of cellulose with hot aqueous liquids, as in dyeing, scouring and degumming operations, damage to the pile is minimized by effecting the treatment in the presence of a substantially neutral substance, e.g. a readily ionisable salt or a sugar capable of exerting osmotic pressure but having no substantial swelling action on the cellulose derivatives. The salt used may be, for example, a substantially neutral sulphate, chloride, nitrate, chromate or acetate of sodium, potassium, magnesium, ammonium or aluminium and the sugar may be, for example, cane sugar. The concentration of the substantially neutral substance is suitably 0.5--10 per cent. The pile may be, for example, of cellulose acetate, formate, propionate or butyrate or of ethyl-, methyl-, or benzyl-cellulose and the fabric may contain also other fibres, e.g. of silk, cotton, regenerated cellulose or wool. The process is particularly advantageous in the degumming in a hot alkaline soap bath of a fabric having a pile made of or containing an organic ester of cellulose and containing natural silk in the pile or in the backing or in both. Saponification of the cellulose ester is avoided by adjusting the alkalinity to a pH value of not more than about 10--10.5 by means of sodium or potassium hydroxide or carbonate or, more suitably, by means of less strongly alkaline salts, e.g. di- or tri-sodium or potassium phosphates or borax. In an example a velvet fabric having a cellulose acetate pile and a natural silk backing is degummed by treatment for 1\ba1/2\be--2\ba1/2\be hours in a bath at about 95 DEG C. containing olive oil soap, disodium phosphate and sodium sulphate. Specifications 246,879, 259,266, and 260,312, [all in Class 2 (ii)], are referred to.