GB544820A - Improvements relating to the production of pattern effects on textile fabrics - Google Patents

Abstract

544,820. Artificial silk ; treating textiles with liquids ; dyeing processes. HARDACRE, R. W., and IMPERIAL CHEMICAL INDUSTRIES, Ltd. Oct. 28, 1940, No. 15745. [Classes 2 (ii) and 15 (ii)] Textile fabrics composed of synthetic linear polyamides are crimped by locally treating them, e.g. by printing, with an aqueous medium having a swelling effect and containing zinc chloride or a metallic thiocyanate, removing water from the locally treated portions, and then steaming. The printed portions of the fabrics are endowed with an increased affinity for direct, azoic, vat, and cellulose acetate dyestuffs. The polyamides may be derived from monoamino monocarboxylic acids or their lactams, e.g. 6-amino-caproic, 7-aminoheptanoic, or 11-amino-undecanoic acid, or from diamines and dicarboxylic acids examples of such polyamides being polytetramethylene sebacamide, polyhexamethylene adipamide, and polyhexamethylene sebacamide. The filaments may be obtained by melt spinning and may be cold drawn. Calcium or zinc thiocyanate may be used as swelling agent. The fabric may be printed with the aqueous solution of metallic salt, dried, steamed at 100‹C. whilst in tensionless condition, washed, and dried in tensionless state. If desired the fabric may first be printed with a resist such as starch paste or gum and then immersed in the metallic salt solution. The salt solution may contain a thickener such as gum senegal and a wetting agent. Dyes may also be included in the salt solution but it is preferred to dye the fabric after treatment with the salt solution. In an example, polyhexamethylene adipamide is printed with a paste made by mixing calcium thiocyanate solution, gum senegal solution, water, and the substance sold under the Registered Trade Mark " Perminal K B." The fabric is dried, steamed without tension, washed, and dried without tension. The printed portions shrink and the fabric becomes crinkled. On dyeing with " Chlorazol " Yellow R.S., the printed portions dye a deep yellow whereas the unprinted portions are practically untinted. Specifications 461,236, 461,237, 474,999, and 495,790, are referred to.