High strength low shrinkage polyester drawn yarn, and a process of preparing for the same

Abstract

The present invention discloses a high strength low shrinkage polyester drawn yarn used as industrial yarns and a process or producing the same. The strength low shrinkage polyester drawn yarn has a thermal relaxation stress change ratio of 5 to 100% and a thermal relaxation stress area ratio of 50 to 140% on a thermal relaxation and shrinkage stress curve with a final temperature set to 170° C. The process for producing a high strength low shrinkage polyester drawn yam by a direct spin draw (DSD) process in which a quenching delay region I is mounted, wherein the high strength low shrinkage polyester drawn yarn is produced in such methods that a spinning oil is attached to the yarn being spun with an oiling apparatus 8 mounted at the position 500 to 1,500 mm below from the lower bottom surface of the insulating board 3 , the relaxation stress of the yarn is controlled with one or tow tension guides 9 mounted between Godet rollers of a relaxation region III, or both oiling apparatus 8 and tension guides 9 are mounted.

1 . A process for producing a high strength low shrinkage polyester drawn yarn by a direct spin draw process in which a quenching delay region I having a vertical array of a hood heater and an insulating board is mounted between a spinneret and a quenching chamber, wherein the high strength low shrinkage polyester drawn yarn is produced in such methods that a spinning oil is attached to the yarn being spun with an oiling apparatus mounted at the position 500 to 1,500 mm below from the lower bottom surface of the insulating board, the relaxation stress of the yarn is controlled with one or two tension guides mounted between Godet rollers of a relaxation region III, or both oiling apparatus and tension guides are mounted.  
   
   
       2 . The process of  claim 1 , wherein the temperature of the hood heater is 250 to 350° C. and the length thereof is 200 to 400 mm.  
   
   
       3 . The process of  claim 1 , wherein the length of the insulating board is 60 to 300 mm.  
   
   
       4 . The process of  claim 1 , wherein the yarn detention time in the quenching delay region I is 0.02 to 0.08 seconds.  
   
   
       5 . The process of  claim 1 , wherein the spinning tension is less than 0.3 g/d.