Improvements relating to finishing treatment of cellulosic materials including cotton and like fibres, yarns and fabrics

摘要

Cellulosic textile materials, e.g. fabrics or yarns, are given a mechanical glaze-finish treatment to a high degree, as by passing several times through a hot calender or Schreiner, and are then subjected to a treatment with a swelling and solvent agent for the cellulose, for the purpose of removing surface roughness, the treatment being so controlled that only a surface plasticising or solution of the materials takes place, and the dissolved cellulose is re-precipitated as a thin coating on the fibres on removal or neutralization of the solvent. The glaze-finish is rendered permanent to washing or splashing with water. The treatment is controlled by regulating the strength of the treatment bath and adjusting the amount of reagent left on the fabric, e.g. by varying the period of immersion, the rate of passage through the reagent, and the degree of expression on leaving the treatment bath. The treated materials may be washed before the solvent is neutralized so as to remove some of the dissolved cellulose before the re-precipitation occurs. The solvent may be a solution of copper hydroxide in ammonia or in an alkylamine, alkylene amine, or primary aliphatic diamine, or it may be a solution of urea or thio-urea in caustic soda, or of zinc oxide in caustic soda. In an example, mercerized bleached sateen is heavily calendered by passing it several times through a calender at 200 DEG C. to produce a high gloss. It is then passed through cuprammonium solution containing 13.5 grams of copper, 600 c.c. of 880 ammonia, and 20 c.c. of 80 DEG twaddell caustic soda per litre. It is squeezed through a heavy nip, and after a short interval, is treated with acid. A glazed chintz finish is obtained. By increasing the strength of the bath and using suitable fabrics, stiffer finishes may be obtained. Starches or other fillers may be incorporated in the fabrics before or after the treatment. Instead of cuprammonium solution, a solution of copper hydroxide in ethylene diamine hydrate, propylene diamine hydrate, or di-ethylene triamine, may be used. If desired, the swelling agent may be applied locally so as to obtain pattern effects, which may be intensified by dyeing so as to obtain two-tone or two colour effects. Specifications 251,102, 301,392, 334,756, [all in Class 15 (ii)], 403,255, 468,633 and 469,020 are referred to.