GB524090A - Manufacture of artificial fibres from protein material - Google Patents

Abstract

524,090. Artificial filaments, bristles &e. albumens. TRAILL, D., SEDDON, R. V., SEVER, W., and IMPERIAL CHEMICAL INDUSTRIES, Ltd. Jan. 21, 1939, Nos. 2150 and 18569. [Classes 2 (ii) and 2 (iii)] Artificial filaments, including bristles, are obtained by extrusion into a coagulating bath of a thixotropic viscous solution which has been made by maintaining at a temperature not below about 60 ‹C. a dispersion of ground-nut protein in dilute aqueous ammonia until an increase in natural viscosity at least of the order of 5-fold has been obtained. The protein content of the dispersion may be 10-25 per cent. and the ammonia concentration may be 0.5-1.0 per cent. The thermal treatment may be such that the viscosity attained is the same as that attained after 2.5-3.0 hours heating at 70‹C. The viscosity of the hot viscous solution or jelly obtained by the heat treatment may be reduced by a mechanical shearing treatment, and a similar treatment may be applied during the heat treatment to avoid the formation of a jelly. Dispersion of the protein in the aqueous ammonia may be assisted by mechanical homogenization and by warming to a temperature below 60 ‹C. The mechanical shearing may be effected by means of a colloid mill, emulsifier, or homogeniser. The temperature of extrusion is not necessarily the same as that of the heat treatment. The coagulating liquid may be a solution of sulphuric acid with or without sodium or ammonium sulphate. The fibres produced may be subjected to treatment with formaldehyde or other hardening agent and to treatment to increase their resistance to damage by wet treatment liquids. In an example, a heat treated ground-nut protein dispersion is cooled, aged, and spun into sulphuric acid solution. The thread is drawn without tension from the bath, then passed into formaldehyde solution and over stretching rolls. It is washed, dried, and cut into bristles. These are soaked in a solution of thionyl chloride in carbon tetrachloride. In another example, the thread after treatment with formaldehyde and drying is cut to bristles and these are soaked in saturated brine containing formaldehyde and hydrochloric acid. In another example, a ground-nut protein dispersion in ammonia solution is passed into a circulating device comprising an open reservoir, a constant delivery pump, a tube or jet type of homogeniser, a heating coil and a manometer attached to a conduit leading to the reservoir. The viscosity of the moving liquid is approximately a linear function of the pressure recorded by the manometer. The dispersion is first circulated for some time without heating. The homogeniser, heating coil and reservoir are then heated by means of hot water, and the circulation is continued until the desired increase in viscosity is attained. The cooled solution is extruded into a salt-acid bath and the filaments are wound at high speed. Specifications 492,677, 492,895, 495,332, 513,896 and 513,910 are referred to.