GB740612A - Process for the manufacture of artificial fibres from polymeric caprolactam - Google Patents

Abstract

In the manufacture of artificial fibres from polymeric e -caprolactam by melt-spinning, the unstretched fibres are first washed with an aqueous medium advantageously above 50 DEG C., preferably at 80-100 DEG C., then lubricated in a separate operation by an emulsion of the oil-in-water type, and then conditioned in an atmosphere of relative humidity 55-70 per cent, preferably 60 per cent, at 17-25 DEG C., preferably 19-20 DEG C. The fibres may be dyed, e.g. with acid dyestuffs or cellulose acetate dyestuffs, at the same time as they are washed. The wash liquid may be water, aqueous solutions of salts such as sodium chloride or dilute aqueous solutions of alkalies. The emulsified lubricant may be oleic acid, an oil or a fat and the emulsion may contain a soap, e.g. ammonium oleate or a mixture thereof with triethanolamine oleate. In an example, polymerized e -caprolactam containing 12 per cent of water-soluble material is meltspun to form a loose cake of twisted yarn, which is washed with water at 96 DEG C. for one hour. It is then centrifuged, lubricated by immersion in a 6 per cent aqueous solution of ammonium oleate in which 7 per cent of oleic acid has been emulsified and suspended for 36 hours in an atmosphere of relative humidity 60 per cent at 20 DEG C. The yarn is then stretched in the ratio of 1 : 4 (initial to final length) and further twisted. The emulsion may alternatively consist of 13 per cent of mineral spindle oil emulsified in a 6 per cent solution of ammonium oleate. U.S.A. Specifications 2,253,176 and 2,300,083 are referred to.