GB667115A - Improvements in and relating to the production of artificial protein threads, fibres, filaments, yarns and the like - Google Patents

Abstract

Artificial threads are obtained by extruding a viscous spinning solution of a mixture of keratin and a fibre-forming casein in an aqueous alkaline sodium sulphide solution into an aqueous saline coagulating bath having a pH value between 6.0 and 9.0. Preferably the mixture of keratin and casein comprises 30-70 per cent by weight of keratin and 70-30 per cent of casein. Crude keratin such as wool waste or pieces of horn or hoof may be treated with sodium sulphide solution, and the solution obtained may be separated from the undissolved residue. The keratin solution may be added to an alkaline solution of casein, or swollen casein may be added to the keratin solution. Caustic soda may also be added to the sodium sulphide solution. The casein may be of animal or vegetable origin, i.e. it may be lactic casein or casein from peanuts, castor beans, or soya beans. The coagulating bath may be a concentrated solution of sodium sulphate or of sodium and magnesium sulphates and it may be used at 30-60 DEG C. The threads obtained may be hardened and stretched, and may be rendered resistant to hot water and other hot aqueous liquids. In an example, a solution of wool waste in sodium sulphide solution is mixed with a solution of milk casein in caustic soda solution. The mixed solution is centrifuged, de-aerated, and then extruded into a coagulating bath comprising an aqueous solution of sodium and magnesium sulphates adjusted to a pH value of 8.0 by the addition of caustic soda, the temperature being 50 DEG C. In another example, dry milk casein and a small proportion of oleic acid are added to the solution of keratin in sodium sulphide solution. Specifications 306,464, [Class 2 (ii)], 444,626, 502,710, 505,756, 506,895, 517,956, 538,338, 549,642, and 573,015, are referred to. The Provisional Specification also refers to Specifications 546,977, 567,904, and 614,506.