POROUS HOLLOW YARN MADE OF POLYETHYLENE

摘要

PURPOSE:To obtain porous hollow yarn which is capable of high-pressure vapor sterilization and excellent in heat resistance by regulating m.p. of hollow yarn produced in a stretch opening method to a specified temp. and regulating degree of shrinkage in the lengthwise direction of yarn at high-pressure vapor sterilization temp. to a specified proportion and below. CONSTITUTION:High-density polyethylene is used as a raw material and spun in the temp. range within a temp. range of m.p. to about 50 deg.C above mp. at about >=100 draft ratio and cooled and thereafter subjected to annealing treatment at about 90-125 deg.C. This nonstretched raw yarn is subjected to low stretching at about <=50 deg.C and one-stage or multistage thermal stretching is successively performed at about 90-125 deg.C and thereafter one-stage or multistage thermal setting is performed. In this case, thermal setting temp. is regulated to about 125 deg.C to 130 deg.C and degree of relaxation is regulated to 20-50% and thereby the following porous hollow yarn made of polyethylene is obtained wherein m.p. is between 130 deg.C and 150 deg.C and degree of shrinkage in the lengthwise direction of yarn under nonextension at 121 deg.C is <=10%.