GB570205A - Improvements in the manufacture and production of artificial filaments, threads and the like - Google Patents

Abstract

Artificial filaments are obtained by extruding a solution of casein or similar protein, e.g. protein from soya beans, peanuts, sesame or flax seeds, through a single- or multiple-hole jet or jets into a coagulating liquid, treating the filaments so formed with a hardening liquid containing formaldehyde and ammonia, stretching the so-treated filaments, and then treating them for a second time with a hardening agent without allowing them to contract. Contraction may be prevented by tensioning the filaments or by effecting the hardening in the presence of salts, e.g. sodium sulphate or calcium chloride. Instead of mixing formaldehyde and ammonia for the preliminary hardening, the compound hexamethylene tetramine may be used. If desired, the preliminary hardening may be carried out simultaneously with coagulation by adding the hardening agent to the coagulating liquid or by adding hexamethylene tetramine to the casein solution before it is extruded. In an example, a solution of casein in dilute caustic soda solution is extruded into a coagulating bath containing sulphuric acid and sodium sulphate in aqueous solution at a temperature of 55 DEG C. The resulting thread is subjected for 30 minutes while passing over rollers to the action of a solution containing aluminium sulphate, soda ash, hexamethylene tetramine, the synthetic tanning agent of the sulphonated phenolformaldehyde type, "Nerodol" (Registered Trade Mark), and sodium sulphate. The thread is then stretched in a hot solution of sodium sulphate and wound on to a drum. It is cut off into staple fibres and then hardened by treatment with a solution made by mixing aluminium sulphate, soda ash, formaldehyde and water. The cut material is further hardened by immersion in a solution of sodium bisulphate and formaldehyde. Specifications 502,710, 525,158 and 549,642 are referred to.