GB315405A - Improvements relating to the manufacture of artificial threads, bands, films and the like from viscose solutions - Google Patents

Abstract

315,405. Zellstofffabrik Waldhof, and Bernstein, A. July 13, 1928, [Convention date]. Cellulose xanthates, processes for making filaments and films from; apparatus for making filaments and films.-In a process wherein artificial silk, films, &c. are made from viscose by coagulating the viscose in a bath containing inorganic salts or suitable organic coagulants and then treating the coagulated products in an acid bath, the two baths are arranged as separate compartments of a single container. In the apparatus shown the container 1 is divided by the partition e into two compartments A and B, which contain respectively the coagulant, for example a 30 per cent salt solution, and acid, for example 30 per cent sulphuric acid. The viscose is forced through nozzles a into the coagulants, which enters compartment A through pipe f and flows out through the overflow pipe g, and the coagulated filaments are passed through the acid, which enters compartment B through pipe f<1> and flows out through the overflow pipe g'. The filaments b on leaving the acid bath possess great strength, so that they can be led off without difficulty over thread guides h on to suitable winding devices d but they are preferably washed with warm water or steam shortly after leaving the acid bath. The process is particularly suitable for the production of very fine filaments. The Specification as open to inspection under Sect. 91 (3) (a) states that the partition is preferably interrupted adjacent the liquid level to allow passage of the filaments. This subjectmatter does not appear in the Specification as accepted.