Polyester fiber and method for producing same

Abstract

Disclosed is a high strength and high elongation polyester fiber being used for anchoring, mooring, or towing a ship, and particularly is a polyester fiber wherein the recovered work ratio at the elongation corresponding to 10% of the maximum load measured at room temperature is 70% or more, the recovered work ratio at the elongation corresponding to 20% of the maximum load is 50% or more, and the recovered work ratio at the elongation corresponding to 30% of the maximum load is 40% or more, a method of preparing the same, and a polyester fiber rope including the same.

1 . A polyester fiber, wherein the recovered work ratio at the elongation corresponding to 10% of the maximum load measured at room temperature is 70% or more, the recovered work ratio at the elongation corresponding to 20% of the maximum load is 50% or more, and the recovered work ratio at the elongation corresponding to 30% of the maximum load is 40% or more. 
     
     
         2 . The polyester fiber according to  claim 1 , wherein the total fineness is 900 denier or more. 
     
     
         3 . The polyester fiber according to  claim 1 , which is comprised of a plurality of monofilaments, wherein the fineness of the individual monofilaments is 21 DPF or less and the total number of the filaments is 110 to 550. 
     
     
         4 . The polyester fiber according to  claim 1 , wherein the tensile tenacity is 8.8 g/d or more and the elongation at break is 15% or more. 
     
     
         5 . A method of preparing the polyester fiber according to  claim 1 , including the steps of:
 preparing a polyester undrawn fiber by melt-spinning a polyester polymer having an intrinsic viscosity of 1.2 dl/g or more at 270 to 310° C., and   drawing the polyester undrawn fiber.   
     
     
         6 . The method according to  claim 5 , wherein the polyester polymer includes 70 mol % or more of polyethylene terephthalate. 
     
     
         7 . The method according to  claim 5 , wherein the drawing step is carried out with the drawing ratio of 5.0 to 6.5. 
     
     
         8 . The method according to  claim 5 , further including a heat-setting process of the temperature of 170 to 250° C. after the drawing step. 
     
     
         9 . The method according to  claim 5 , further including a relaxation process of the relaxation ratio of 1% to 14% after the drawing step. 
     
     
         10 . A polyester fiber rope, including the polyester fiber according to  claim 1 . 
     
     
         11 . The polyester fiber rope according to  claim 10 , wherein the strength at break per unit diameter (mm) is 0.67 ton/mm or more. 
     
     
         12 . The polyester fiber rope according to  claim 10 , wherein the elongation at break is 18% or more. 
     
     
         13 . The polyester fiber rope according to  claim 10 , wherein the strength maintenance rate is 90% or more. 
     
     
         14 . The polyester fiber rope according to  claim 10 , wherein the moisture absorption rate is 2% or less. 
     
     
         15 . The method according to  claim 5 , wherein the total fineness of the polyester fiber is 900 denier or more. 
     
     
         16 . The method according to  claim 5 , wherein the polyester fiber is comprised of a plurality of monofilaments, wherein the fineness of the individual monofilaments is 21 DPF or less and the total number of the filaments is 110 to 550. 
     
     
         17 . The method according to  claim 5 , wherein the polyester fiber has the tensile tenacity of 8.8 g/d or more and the elongation at break of 15% or more. 
     
     
         18 . The polyester fiber rope according to  claim 10 , wherein the total fineness of the polyester fiber is 900 denier or more. 
     
     
         19 . The polyester fiber rope according to  claim 10 , wherein the polyester fiber is comprised of a plurality of monofilaments, wherein the fineness of the individual monofilaments is 21 DPF or less and the total number of the filaments is 110 to 550. 
     
     
         20 . The polyester fiber rope according to  claim 10 , wherein the polyester fiber has the tensile tenacity of 8.8 g/d or more and the elongation at break of 15% or more.