Hollow polyester long fiber and preparation method therefor

Abstract

A hollow polyester long fiber has a cross-sectional hollowness ranging from 20.0% to 45.0%, the long fiber in natural state being of a three-dimensionally crimped shape, and the radius of curvature of the crimped shape being 10.0 mm to 50.0 mm. The fluffy processed tows obtained by processing the hollow polyester long fiber have high fluffiness.

1 .- 8 . (canceled) 
     
     
         9 . A hollow polyester long fiber having a cross-sectional hollowness of 20.0% to 45.0%, and the long fiber has a three-dimensionally crimped shape in a natural state, and the crimped shape has a radius of curvature of 10.0 mm to 50.0 min. 
     
     
         10 . The hollow polyester long fiber according to  claim 9 , wherein the long fiber has a monofilament fineness of 4.0 dtex to 15.0 dtex. 
     
     
         11 . The hollow polyester long fiber according to  claim 10 , wherein the long fiber has a monofilament fineness of 5.0 dtex to 10.0 dtex. 
     
     
         12 . The hollow polyester long fiber according to  claim 9 , wherein the long fiber has a radius of curvature of 3.5 mm to 10.0 mm after dry heat treatment at 160° C. for 3 minutes. 
     
     
         13 . The hollow polyester long fiber according to  claim 9 , wherein the polyester is selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate or a modified polymer thereof. 
     
     
         14 . A method of preparing the hollow polyester long fiber according to  claim 9 , wherein a dried chip is melt-extruded by a screw and then conveyed to a metering pump through a pipe, the polymer accurately measured by the metering pump is conveyed to a spinning pack, a spinneret of the spinning pack is a hollow spinneret with a cooling distance of 10 to 150 mm, and a wind speed of side blowing of 25 to 90 m/min. 
     
     
         15 . The method according to  claim 14 , wherein the cooling distance is 60 to 110 mm. 
     
     
         16 . The method according to  claim 14 , wherein the wind speed of the side blowing is 30 to 50 m/min. 
     
     
         17 . The hollow polyester long fiber according to  claim 10 , wherein the long fiber has a radius of curvature of 3.5 mm to 10.0 mm after dry heat treatment at 160° C. for 3 minutes. 
     
     
         18 . The hollow polyester long fiber according to  claim 10 , wherein the polyester is selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate or a modified polymer thereof. 
     
     
         19 . The method according to  claim 15 , wherein the wind speed of the side blowing is 30 to 50 m/min.