GB489017A - Improved treatment of animal and vegetable fibers - Google Patents

Abstract

Animal fibres, e.g. rabbit hair, wool, or tussah silk, and vegetable fibres, e.g. ramie, jute, or flax, are bleached by subjecting them to the action of a chemically-acting swelling agent and, thereafter, to the action of an agent which removes colouring matter from the interior of the swollen fibres. The bleaching is suitably preceded by a treatment with an aqueous solution of calcium hydroxide or other alkali. Suitable swelling agents used are, for animal fibres, lactic acid and, for vegetable fibres, sodium carbonate, each in an aqueous solution containing hexyl alcohol, hexamethylenetetramine, glycerol, hydrogen peroxide, sodium pyrosulphate and a chlorinated detergent, the treatment being effected under pressure at temperatures rising to 175 DEG F. The subsequent treatment may be similarly effected with a similar solution from which the hexyl alcohol and hexamethylenetetramine are omitted and ammonia may be substituted for the pyrophosphate. The hexyl alcohol may be replaced by octyl, propyl or isopropyl alcohol, the glycerol by other glycols and the hexamethylenetetramine by urea derivatives. Silk is preferably subjected to an additional treatment with a cold aqueous solution containing hexyl alcohol and hydrochloric or sulphuric acid. Other animal fibres are preferably subjected to an additional treatment with an aqueous solution at 150 DEG F. of hexamethylenetetramine.