Patent ID: 7022280
Filing Date: 2006-04-04
Classification: D01D,D01F,Y10T

Abstract:
1. A process for producing a flat yarn, which comprises the steps of: (a) providing a polyoxymethylene copolymer having a melt index at 190° C. with a load of 2160 g of 0.3 to 20 g/10 min., the polyoxymethylene copolymer being comprised mainly of repeating oxymethylene units and containing 0.5 to 10 moles of oxyalkylene units represented by the following formula (1) per 100 moles of the oxymethylene units in the polymer chain:  in which R (b) melting the polyoxymethylene copolymer provided according to step (a) and forming a film therefrom by inflation extrusion or T-die extrusion; (c) slitting the film obtained according to step (b) into a plurality of strips by passing the film through a slitter; (d) monoaxially stretching the strips obtained in step (c) 2 to 15 times at a temperature of between 80° C. and 170° C.; and then (e) heat-setting the monoaxially stretched strips at a temperature between 120° C. and 180° C. to obtain a flat yarn thereof.