Polyester yarn and process for producing

Abstract

A multi-filament poly(trimethylene terephthalate) yarn is provided. The poly(trimethylene terephthalate) yarn has a crystal orientation function of at least 0.6 and an elongation at break of between 65% and 110%. A process for producing the yarn is also provided in which poly(triemethylene terephthalate) is melt-spun into a multi-filament yarn, the yarn is cooled to a yarn temperature of less than 50° C., and the cooled yarn is taken-up at a take-up speed of at least 3500 m/min while maintaining the temperature of the yarn at a yarn temperature of less than 50° C.

1 . A yarn comprising, a poly (trimethylene terephthalate) yarn having a crystal orientation function of at least about 0.6 and an elongation at break of between 65% and 110%.  
   
   
       2 . The yarn of  claim 1  wherein the poly (trimethylene terephthalate) yarn has a heat of fusion of at least about 12 calories/gram.  
   
   
       3 . The yarn of  claim 1  wherein the poly(trimethylene terephthalate) yarn has an initial birefringence of at least about 0.05.  
   
   
       4 . The yarn of  claim 1  wherein the poly(trimethylene terephthalate) yarn has an initial boil-off shrinkage of at most about 22%.  
   
   
       5 . The yarn of  claim 1  wherein the poly(trimethylene terephthalate) yarn has a boil-off shrinkage after thirty days of from the initial boil-off shrinkage less about 10% to the initial boil-off shrinkage.  
   
   
       6 . The yarn of  claim 1  wherein the poly(trimethylene terephthalate) yarn has a meridianal two-point small-angle X-ray scattering pattern corresponding to a crystalline/amorphous phase lamellar periodicity of from about 50 to about 100 angstroms.  
   
   
       7 . The yarn of  claim 1  wherein the poly(trimethylene terephthalate) yarn has a tenacity of at least 2.5 g/denier.  
   
   
       8 . A yarn package comprising the yarn of  claim 1 .  
   
   
       9 . The yarn package of  claim 8 , wherein the yarn package weighs at least about 5 kg.  
   
   
       10 . A process for forming a poly(trimethylene terephthalate) yarn comprising: 
 melt-spinning poly(trimethylene terephthalate);    cooling the melt-spun poly(trimethylene terephthalate) into a multi-filament yarn having a yarn temperature less than 50° C.; and    taking up the multi-filament yarn having a yarn temperature less than 50° C. at a take-up speed of at least about 3500 m/min while maintaining the yarn at a yarn temperature of less than 50° C.    
   
   
       11 . The process of  claim 10  further comprising winding the yarn onto a yarn package.  
   
   
       12 . The process of  claim 11  further comprising: 
 unwinding the yarn from the yarn package; and    drawing and texturing the unwound yarn.    
   
   
       13 . The process of  claim 12  wherein the yarn is unwound from the yarn package at least one day after winding the yarn onto the yarn package.  
   
   
       14 . A yarn comprising, a polytrimethylene (terephthalate) yarn having an initial boil-off shrinkage of at most 22%; a boil-off shrinkage after thirty days of from the initial boil-off shrinkage less 10% to the initial boil-off shrinkage; and an elongation at break of between 65% and 110%.  
   
   
       15 . The yarn of  claim 14  wherein the poly (trimethylene terephthalate) yarn has a heat of fusion of at least 12 calories/g.  
   
   
       16 . The yarn of  claim 14  wherein the poly (trimethylene terephthalate) yarn has a tenacity of at least 2.5 g/denier.  
   
   
       17 . A yarn package comprising the yarn of  claim 14.