GB482628A - Improvements in or relating to the manufacture of shaped products from animal fibrous starting materials - Google Patents

Abstract

Flexible tubes, sheets, threads, and other shaped products are prepared from highly swollen animal fibrous masses which contain from 90 to 99 per cent of water and are of so thin a consistency that they cannot in themselves retain the shape imparted to them by the shaping devices, by treating the masses immediately after leaving the shaping devices with baths consisting of organic liquids miscible with water, or water-removing salt solutions, and/or solutions of substances which neutralize or remove the swelling agents and which may contain hardening or tanning agents. The shaped products are finally solidified by drying, hardening or tanning. Examples of baths are alcohol, acetone, solution of salt, ammonium chloride or sodium sulphate. With acid-swollen masses alkaline baths, e.g., bicarbonate solution, and with alkaline-swollen masses acid baths, e.g. hydrochloric acid or ammonium chloride may be used. Suitable tanning agents are formaldehyde, distillates from cellulose-containing materials, e.g., wood smoke, condensates, aluminium and chromium salts, train oil and train oil acids, vegetable or synthetic tanning-agents. Specifications 429,040 and 433,245 are referred to. The highly swollen masses are obtained by treating the fibrous starting material with chemical swelling agents such as acids and bases, with the addition, if desired, of substances which increase the swelling action, e.g., thiocyanates, mixtures of ammonia and carbon disulphide, and phenol. The Specification as open to inspection under Sect. 91 relates to a process wherein flexible tubes, thin sheets, threads or other shaped articles obtained from highly swollen fibrous animal materials are treated, immediately after leaving the shaping device, on one or both sides with aqueous solutions of acids, bases or salts, or organic liquids miscible with water and are only thereafter dried and treated with tanning or hardening agents. The animal fibrous material may contain vegetable fibres or threads, e.g., viscose may be added to an alkaline-swollen fibrous mass. This subject-matter does not appear in the Specification as accepted.