GB327423A - Improvements in or relating to the manufacture of artificial threads by the dry spinning method - Google Patents

Abstract

327,423. Carpmael, A., (I. G. Farbeninindustrie Akt.-Ges.). Nov. 3, 1928. Cellulose esters and ethers, processes for making filaments from; apparatus for making filaments.-In the manufacture of artificial threads by dry spinning from solutions of esters or ethers of cellulose or its conversion products, the solution to be spun is preheated to a temperature higher than that at which the solvent or solvent mixture begins to boil at ordinary pressure, and is extruded into a chamber in which a current of air or other gas at a lower temperature passes in counter-current to the threads. Preferably, the solution is heated to the highest possible temperatune compatible with the production of continuous threads, and is extruded into a stream of air or other gas at ordinary or slightly raised temperature. Precautions should be taken to avoid radiation of heat from the nozzle into the surrunding atmosphere, which should be 20-50‹ C. lower in temperature than the solution. When working with a spinning atmosphere of very low temperature, a very long and narrow spinning chamber should be used. The air or other gas may be charged with a solvent preferably the same as that used in making the solution, and the solvent may include an aromatic hydrocarbon, particularly when spinning acidyl celluloses. Threads prepared as described above show advantageous properties in respect of strength, appearance, and resistance to boiling water. Examples are given describing the manufacture of threads under various conditions as set out above from solution of (1) cellulose acetate in acetone and ethyl alcohol, (2) cellulose acetate in acetone, benzene, and ethyl alcohol, (3) celluose acetate in acetone and benzene, (4) cellulose acetate in acetone and toluene, and (5) ethyl cellulose in methyl alcohol, toluene, and xylene. Specification 278,814 is referred to.