GB665199A - Improvements in or relating to methods of sizing nylon fibres and yarn - Google Patents

Abstract

Nylon fibres or warp yarns are treated with an aqueous solution of the ammonium, a quaternary ammonium, or the sodium or potassium salt of a copolymer of styrene or a substituted styrene with an alkyl ester of maleic acid in which the alkyl group contains 1-4 carbon atoms, and then dried. The solution is free from substances which would react with the salt of the copolymer on heating to form an insoluble resin, and the fibres or yarns are not subjected to any after-treatment with such substances. Drying may take place at 200-300 DEG F. The sized nylon warp yarns may be woven into a fabric and the fabric may be subjected to finishing treatments without first desizing it. The treatment decreases the amount of dusting and shedding during weaving operations and improves the strength of the yarns. The sizing solution may be applied at raised temperature, e.g. 120-150 DEG F., or, if desired, at room temperature without gelling. The sized yarns may be dried by passage over heated rollers or by means of a current of air. The alkyl group of the maleic ester may be methyl, ethyl, propyl, butyl, or secondary butyl. The concentration of the copolymer salt in the bath and the pick-up of the sizing rolls should be adjusted to deposit on the yarns 2-12 per cent by weight of the salt. If a semi-permanent stiff finish is desired, it is necessary when ammonium salts are used to dry the yarns, or the fabrics produced from them, at a temperature, e.g. 250-300 DEG F., sufficiently high to set the resin. When sodium or potassium salts are used, the resin may be set by subjecting the yarns or fabrics to a dilute acid bath. The copolymer may be prepared by heating styrene and a maleic ester at 100-300 DEG F. for several hours using, e.g., 1 mol. of styrene to 0.25-4 mols. of maleic ester. A solvent such as acetone and a catalyst such as benzoyl peroxide may be present. If desired, a copolymer of styrene and maleic anhydride may be prepared first and then esterified, or a mixture of styrene, maleic anhydride, and an alcohol may be subjected to polymerization treatment. The fabric obtained by weaving the sized yarns may be dyed and finished without preliminary de-sizing. Softening agents, e.g. sulphonated oils, ethylene oxide condensation products, soaps, emulsified tallow or oils, or glycerine, may be added to the size bath. Instead of sizing the yarns, the component fibres may be sized at any stage before spinning.