GB443706A - Improvements in and relating to the production or manufacture of threads or filaments of artificial silk and the like - Google Patents

Abstract

<PICT:0443706/IV/1> Artificial filaments or the like of cellulose or cellulose derivatives are obtained by applying a cellulosic solution to a knife or equivalent fine edge, effecting solidification at least to the stage where it is capable of being withdrawn in a coherent condition, and withdrawing the filament thus formed. The edge may be a thin wire. In the case of a knife edge, a rotating member such as a disc may provide the support for the knife edge which may receive the cellulosic solution by contact with a rotating roller dipping into the solution, or the knife edge itself may dip into the solution. The cellulosic solution may be solidified by means of a liquid coagulant or by means of heat. Sulphuric acid or caustic soda are specified coagulants. Filaments may be taken from a knife-edge disc under stretching tension. A tension roller may run in coagulant or be continuously supplied with powder to prevent adhesion of the thread which may pass twice round the roller, a spacing guide being provided, and it may pass to another roller rotating at a greater speed. The filament may have powder applied to it between the two rollers. The filament may be removed from the disc without stretching. Instead of a knife-edged disc, a fine edged ribbon may be used. When using a fine wire, it is coated with solution and coagulant applied by immersion, spraying, or contact with a moistened roller. When sufficiently solidified, the coating is divided or split and removed from the wire with or without tension. As an alternative the knife-edge or equivalent may first have coagulant applied to it and then be brought in contact with cellulosic solution. Solutions of cellulose acetate, nitrate, xanthate, or cuprammonium solutions of cellulose, with or without rubber latex or other additions may be used. The filaments may be used for making artificial silk fabric, cloth, or lace. As shown, cellulosic solution in trough 5 is taken up by roller 4 and deposited on the knife-edge of disc 1. The thin layer of liquid is carried by the disc into a trough 3 containing coagulating liquid and the coagulated filament is removed from the disc and passed over or round wheel 7 to a winding device. The thickness of solution taken up by roller 4 is regulated by a doctor-roller 6. The Provisional Specification refers to Specification 442,935, [Group V].