GB748889A - Process for improving patterned fabrics - Google Patents

Abstract

Fabrics composed of natural cellulose, regenerated cellulose or cellulose derivative fibres, which have a transparent or translucent foundation and an opaque pattern capable of shrinking under the action of shrinking agents to a greater extent than the base, are subjected to a shrinking treatment and are then tensioned whilst drying and ironed or pressed. The patterned fabric may be obtained by printing with a reserve such as rubber, gum arabic, solutions of cellulose esters or ethers insoluble in water, varnishes, modified or unmodified or substituted synthetic resins or synthetic resin precondensates, and then treating the fabric with a transparentizing agent, selected from aqueous solutions of potassium or sodium hydroxide, aldehydes, sulphuric, nitric or hydrochloric acid, ammonium or calcium thiocyanate, carbon disulphide, cuprammonium solution, mixed nitric and hydrochloric acids, zinc chloride, dimethyl dibenzyl ammonium hydroxide, tetramethyl ammonium hydroxide, a mixture of acetone or chloroform with ethyl alcohol, or acetic or formic acid. The agent and its concentration and temperature are selected according to the materials treated. The transparentizing solution may include buffer salts, e.g. Glauber salt, ammonium sulphate or common salt, and also ethyl alcohol, glycerine or pyridine. After transparentizing, the fabric may be washed and is then treated with a shrinking agent, which agent and its temperature and concentration are also selected according to the fibres treated. Suitable shrinking agents are aqueous solutions of sodium and/or potassium hydroxide, cuprammonium solution, calcium or ammonium thiocyanate, zinc chloride, dimethyl dibenzyl ammonium hydroxide, tetramethyl ammonium hydroxide, hydrochloric acid, nitric acid, formaldehyde, mixtures of alcohols and aldehydes or mixtures thereof with calcium or ammonium thiocyanate or with hydrochloric or nitric acid. Buffer salts, e.g., sodium carbonate, common salt, Glauber salt or ammonium chloride, may be included in the shrinking solution. Mixed fabrics may be used, and one type of fibre may be shrunk independently of the other or both types may be shrunk simultaneously. Prior to the patterning treatment the fabric may be bleached, desized, mercerized or digested. After shrinking, the fabric may be neutralized and washed, and is dried on a tenter to an extent to produce a smooth fabric or beyond this extent to its original dimensions or beyond. Following this, the fabric may be ironed or pressed in hot calenders. The shrinkage treatment is carried out without tension. The examples refer to the treatment of cotton muslin, regenerated cellulose and cellulose acetate fabrics.