GB1073165A - Improvements in or relating to the bleaching of cellulosic textile materials - Google Patents

Abstract

Cellulosic textile materials, e.g. linen and cotton yarns and fabrics, are bleached by impregnating them at a temperature of 80 DEG -120 DEG C. with a limited quantity of an aqueous solution containing an alkali or alkaline earth metal chlorite, e.g. sodium chlorite, and at least one salt which is a sodium or potassium salt of orphophosphoric or boric acid, and having a pH of 5-7 which is maintained in this range during the bleaching operation. The textile materials are impregnated with a quantity of the solution such that substantially no liquid can be drained therefrom although the solution contains the whole of the bleaching agent. The salt, which may be sodium or potassium borate or perborate, mono-or disodium or-potassium-orthophosphate or a mixture thereof, may be present in the solution in an amount between 50 and 150% based on the weight of the chlorite. The solution may also contain a wetting agent, e.g. a polyethenoxylated lauryl alcohol or a sodium alkylaryl sulphonate, and an optical brightening agent. Fabrics may be padded with the bleach solution, squeezed, rolled round a stainless steel shaft or roll, heated in a stainless steel heating chamber and washed. Reels of yarns may be impregnated with the bleach solution, excess liquid extracted by vacuum suction and heating effected by passing steam through the piles of reels.