High shrink sewing machine thread

Abstract

A high shrinkage machine sewing thread comprising one or more high shrinkage yarns having a heat shrinkage factor of not less than 5% at a temperature of 100° C. in a dry state and one or more fuzzed yarns having fuzzes on the yarn surfaces, having the maximum heat shrinkage stress of 0.1 to 0.5 cN/dtex at a temperature of 100 to 150° C. in a dry state, and useful as a machine sewing thread for sewing buttons, a machine sewing thread for waterproof or windbreak products or the like, which need strong seam tightness and good durability.

1 . A high shrinkage machine sewing thread characterized by comprising one or more high shrinkage yarns having a heat shrinkage factor of not less than 5% at a temperature of 100° C. in a dry state and one or more fuzzed yarns having fuzzes on the yarn surfaces and having the maximum heat shrinkage stress of 0.1 to 0.5 cN/dtex at a temperature of 100 to 150° C. in a dry state.  
   
   
       2 . The high shrinkage machine sewing thread according to  claim 1 , wherein the tensile strength of the machine sewing thread is 2 to 4 cN/dtex.  
   
   
       3 . The high shrinkage machine sewing thread according to  claim 1 , wherein the weight ratio of the high shrinkage yarns:the fuzzed yarns is 30:70 to 70:30.  
   
   
       4 . The high shrinkage machine sewing thread according to  claim 1 , wherein the high shrinkage yarns are the multifilament yarns of a copolyester prepared by copolymerizing polyethylene terephthalate with a third component.  
   
   
       5 . The high shrinkage machine sewing thread according to  claim 1 , wherein the fuzzed yarns are polyester spun yarns.  
   
   
       6 . The high shrinkage machine sewing thread according to  claim 1 , wherein the high shrinkage yarns and the fuzzed yarns are primarily twisted at twisting rates of 100 to 1,200 T/m, respectively, and secondarily doubled at a twisting rate which is 50 to 95% of the primary twisting rate.  
   
   
       7 . The high shrinkage machine sewing thread according to  claim 1 , wherein the thread is subjected to a dyeing treatment and then stretched at the ordinary temperature.