Polyester Conjugated Yarn Having High Self-Crimping Properties and Method of Manufacturing the Same

Abstract

Disclosed is a polyester conjugated yarn, including two types of polymers having a large intrinsic viscosity difference subjected to bi-component spinning so as to be longitudinally arranged in a side-by-side sectional structure, in which the twp types of polymers are polyethyleneterephthalate having intrinsic viscosity of 0.45-0.65 as a first polymer and polytrimethyleneterephthalate having intrinsic viscosity of 0.90-1.10 as a second polymer. The polyester conjugated yarn is advantageous in terms of superior spinnability and high uniformity index. In addition, the polyester conjugated yarn can exhibit high self-crimping properties through relaxation-heat treatment of the dyeing and finishing process, and as well, can be applied to manufacture woven/knit fabrics having softness to the touch, beautiful colors, and high drapery and bulk properties, due to inherent characteristics of polytrimentyleneterephthalate.

1 . A method of manufacturing a polyester conjugated yarn, comprising: 
 subjecting two types of polymers having a large intrinsic viscosity difference to bi-component spinning in a spindraw process by use of an inclined circular spinnerette so as to cause the polymers to have a side-by-side sectional structure, the two types of polymers being polyethyleneterephthalate with intrinsic viscosity of 0.45-0.65 as a first polymer and polytrimethyleneterephthalate with intrinsic viscosity of 0.90-1.10 as a second polymer,    wherein the polyester conjugated yarn has a cross section satisfying Equations 1 and 2, below:      0≦(interface ratio=length of line  CD ÷length of line  AB )≦0.6  Equation 1  1≦(shape ratio=length of line  EF ÷length of line  GH )≦1.4  Equation 2    wherein,    line AB: a length of a long axis of an interface between a high viscosity polymer and a low viscosity polymer;    line CD: a length of a short axis of an interface between a high viscosity polymer and a low viscosity polymer/2    line EF: a maximum length of a long axis of a cross section of a yarn;    line GH: a maximum length of a short axis of a cross section of a yarn.    
   
   
       2 . The method according to  claim 1 , wherein the two types of polymers have a melt viscosity difference not more than 2500 poise when being subjected to bi-component spinning.  
   
   
       3 . The method according to  claim 1 , wherein the polyethyleneterephthalate as the first polymer comprises terephthalic acid and ethylene glycol as constitutive monomers, and the polytrimethyleneterephthalate as the second polymer comprises terephthalic acid and propanediol as constitutive monomers, and the first and second polymers do not have an another functional component to be copolymerized.  
   
   
       4 . The method according to  claim 1 , wherein the polyethyleneterephthalate as the first polymer constitutes 30-70 wt %, and the polytrimethyleneterephthalate as the second polymer constitutes 70-30 wt %, based on total weights of the polyester conjugated yarn.  
   
   
       5 . The method according to  claim 1 , wherein the bi-component spinning uses a one-staged spindraw process, in which a first godet roller is set to a rate of 2000 m/min or more, and a second godet roller is set to a rate of 4000 m/min or more.  
   
   
       6 . The method according to  claim 1 , wherein the polyester conjugated yarn has a strength of 2.0-3.3 g/denier, and an elongation of 20-40%.  
   
   
       7 . The method according to  claim 1 , wherein the polyester conjugated yarn has a crimp ratio not less than 20%.  
   
   
       8 . A polyester conjugated yarn, comprising two types of polymers having a large intrinsic viscosity difference subjected to bi-component spinning so as to cause the polymers to have a side-by-side sectional structure, the two types of polymers being polyethyleneterephthalate with intrinsic viscosity of 0.45-0.65 as a first polymer and polytrimethyleneterephthalate with intrinsic viscosity of 0.90-1.10 as a second polymer, 
 wherein the polyester conjugated yarn has a crimp ratio not less than 20% and a circular cross section satisfying Equations 1 and 2, below:      0≦(interface ratio=length of line  CD ÷length of line  AB )≦0.6  Equation 1  1≦(shape ratio=length of line  EF ÷length of line  GH )≦1.4  Equation 2    in which,    line AB: a length of a long axis of an interface between a high viscosity polymer and a low viscosity polymer;    line CD: a length of a short axis of an interface between a high viscosity polymer and a low viscosity polymer/2    line EF: a maximum length of a long axis of a cross section of a yarn;    line GH: a maximum length of a short axis of a cross section of a yarn.