Polytrimethylene terephtalate conjugate fiber and method of preparing the same

Abstract

Disclosed is a polytrimethylene terephtalate conjugate fiber having high self-crimpability, which is prepared by conjugate-spinning two types of polytrimethylene terephtalates having different intrinsic viscosities in which a difference between the intrinsic viscosities ranges from 0.05 to 0.15 into a side-by-side fiber. Also, the polytrimethylene terephtalate conjugate fiber prepared by the conjugate-spinning undergoes a false twisting process, leading to development of three-dimensional high self crimpability and sufficient bulky property in the resulting fiber.

1 . A method of preparing a polytrimethylene terephtalate conjugate fiber, comprising conjugate spinning two types of polytrimethylene terephtalates having different intrinsic viscosities into a side-by-side fiber in which a difference between the intrinsic viscosities ranges from 0.05 to 0.15, under a condition to achieve a difference between melt viscosities of the two polymers in a range of below 1000 poise.  
   
   
       2 . The method as set forth in  claim 1 , wherein the two types of polytrimethylene terephtalates comprise a polytrimethylene terephtalate (PTT-H) having high intrinsic viscosity and a polytrimethylene terephtalate (PTT-L) having low intrinsic viscosity, said PTT-H and PTT-L having different intrinsic viscosities in a range of from 0.7 to 1.1.  
   
   
       3 . The method as set forth in  claim 1 , wherein the two types of polytrimethylene terephtalates comprise a polytrimethylene terephtalate (PTT-H) having high intrinsic viscosity and a polytrimethylene terephtalate (PTT-L) having low intrinsic viscosity, said PTT-H and PTT-L satisfying a ‘K’ value of 0<K≦0.09, calculated according to the following Equation:  
         K={[η]   H −[η] L }/{[η] H +[η] L } wherein, [η] H  is the intrinsic viscosity of PTT-H, and [η] L  is the intrinsic viscosity of PTT-L.    
   
   
       4 . The method as set forth in  claim 1 , wherein the two types of polytrimethylene terephtalates comprise a polytrimethylene terephtalate (PTT-H) having high intrinsic viscosity and a polytrimethylene terephtalate (PTT-L) having low intrinsic viscosity, and content of said PTT-H is 30-70% of total weight of the conjugate fiber and content of said PTT-L is 70-30% of total weight of the conjugate fiber.  
   
   
       5 . The method as set forth in  claim 1 , wherein the two types of polytrimethylene terephtalates comprise a polytrimethylene terephtalate (PTT-H) having high intrinsic viscosity and a polytrimethylene terephtalate (PTT-L) having low intrinsic viscosity, and spinning temperature of the PTT-H and PTT-L is in a range of from 235 to 275° C.  
   
   
       6 . The method as set forth in  claim 1 , wherein the polytrimethylene terephtalates are conjugate-spun into a side-by-side fiber, and the resulting fiber is false-twisted using a friction twisting apparatus, while being drawn simultaneously.  
   
   
       7 . The method as set forth in  claim 6 , wherein the side-by-side fiber prepared at a spinning speed of 1,500-4,000 m/min is false twisted at a false twisting-draw ratio of 1.0-1.5, a false twisting temperature of 100-180° C. and a draw-false twist processing speed of below 1,000 m/min using a false twisting apparatus.  
   
   
       8 . A polytrimethylene terephtalate conjugate fiber comprising two types of polytrimethylene terephtalates having different intrinsic viscosities in which a difference between the intrinsic viscosities ranges from 0.05 to 0.15, and having a side-by-side structure.  
   
   
       9 . The polytrimethylene terephtalate conjugate fiber as set forth in  claim 8 , wherein the conjugate fiber has high crimpability, with a strength of 2.0-3.5 g/den, an elongation of 30-65%, and a crimping rate of over 20%.  
   
   
       10 . The polytrimethylene terephtalate conjugate fiber as set forth in  claim 8 , wherein the conjugate fiber has high crimpability, with an elastic recovery of over 90% at an elongation of 30%.