GB569188A - Improvements in or relating to the impregnation of regenerated cellulose staple fibers - Google Patents

Abstract

Staple fibres of regenerated cellulose are rendered resilient and more amenable to dyeing, carding, spinning, weaving, &c., and to the production of brushed, napped and pile fabrics, by impregnating them under sustained fluid pressure and at a temperature of 30-100 DEG F. with a true solution containing from about 5-20 per cent of resin forming components or the primary condensation products thereof, removing the solution from the surface of the fibres, drying and heating to convert the components to an insoluble resin. Suitable resin-forming components are urea, thiourea, melamine and like carbamides, or phenol, with formaldehyde. Acid-forming catalysts such as ammonium chloride, ammonium phosphate, chloramides, with addition of free ammonia if desired, and lubricants such as long chain quaternary ammonium salt or sulphonated tallow or oils, may be added to the impregnating solution. The fibres are impregnated in a pressure dyeing machine, or in an autoclave, and are then subjected to a hydro-extraction treatment, and, if desired, rinsed with water or a concentrated solution of sodium chloride or sodium sulphate. They are then dried at a low temperature and finally heated by infra-red radiation, steam, or hot air to insolubilize the resin. The fibres may be dyed prior to or after the impregnation process, or dyestuffs may be incorporated in the impregnating solution. In an example, staple viscose fibres are treated under pressure and at a temperature of 55 DEG F. with a 15 per cent solution of dimethylol urea containing small amounts of cetyl-dimethylbenzyl ammonium chloride and diammonium phosphate. The fibres are then hydroextracted, dried, and heated to insolubilize the resin. Specifications 291,473, 291,474, [both in Class 15 (ii)], 449,243 and 462,599 are referred to.