Fiber processing of high ethylene level propylene-ethylene random copolymers by use of nucleators

Abstract

A method of processing a high ethylene random copolymer comprising nucleating a high ethylene random copolymer to form a high ethylene polymeric composition, melting and extruding a high ethylene polymeric composition, spinning a high ethylene polymeric composition to form a fiber, cooling the fiber, guiding the fiber with an aspirator, and recovering the fiber.

1 . A method of processing a high ethylene random copolymer comprising:
 nucleating a high ethylene random copolymer to form a high ethylene polymeric composition,   melting and extruding a high ethylene polymeric composition,   spinning a high ethylene polymeric composition to form a fiber,   cooling the fiber,   guiding the fiber with an aspirator, and   recovering the fiber.   
     
     
         2 . The method of  claim 1  further comprising partially or fully orienting the fiber. 
     
     
         3 . The method of  claim 1  wherein the aspirator comprises an aspirator wand. 
     
     
         4 . The method of  claim 1  wherein the fiber is recovered by winding the fiber on spools. 
     
     
         5 . The method of  claim 1  wherein the high ethylene random copolymer has an ethylene content greater than 3 wt. %. 
     
     
         6 . The method of  claim 1  wherein the high ethylene random copolymer has a xylene solubles content greater than 5 wt. % as measured in accordance with ASTM D 5492-98. 
     
     
         7 . The method of  claim 1  wherein the high ethylene polymeric composition further comprises a visbreaker in amounts ranging from 50 ppm to 1000 ppm. 
     
     
         8 . The method of  claim 1  wherein the high ethylene random copolymer comprises an ethylene-propylene random copolymer. 
     
     
         9 . The method of  claim 1  wherein the high ethylene random copolymer comprises a copolymer of ethylene and an alpha olefin monomer. 
     
     
         10 . The method of  claim 1  wherein the high ethylene random copolymer has a melt flow rate of from 1 g/10 min to 1,000 g/10 min, as determined in accordance with ASTM D-1238. 
     
     
         11 . The method of  claim 1  wherein the high ethylene random copolymer has a melting point of less than 140° C. 
     
     
         12 . The method of  claim 1  wherein the nucleating agent comprises a norbornane carboxylic acid salt in amounts from 50 ppm to 1000 ppm. 
     
     
         13 . The method of  claim 1  wherein the nucleating agent comprises an organophosphate, a sodium benzoate, metal benzoate, a sorbitol compound, a sorbitol derivative, dibenzylidene sorbitol, talc, or combinations thereof. 
     
     
         14 . The method of  claim 13  wherein the nucleating agent is present in amounts from 50 ppm to 3000 ppm. 
     
     
         15 . The method of  claim 1  wherein the high ethylene polymeric composition has an initial tensile modulus of from 60,000 psi to 90,000 psi, as measured in accordance with ASTM D-638. 
     
     
         16 . The method of  claim 1  wherein the high ethylene polymeric composition has an initial stiffness as measured by the flexural modulus of from 60,000 psi to 90,000 psi, as measured in accordance with ASTM D-790. 
     
     
         17 . The method of  claim 1  wherein the fiber has a tenacity greater than or equal to 1.0 g/den as measured in accordance with ASTM D-3822. 
     
     
         18 . The method of  claim 1  wherein the fiber has a draw ratio of from 2.0:1 to 5.0:1. 
     
     
         19 . The method of  claim 1  wherein the fiber has a 5% secant modulus of from 2.0 g/den to 20.0 g/den as measured in accordance with ASTM D-882. 
     
     
         20 . The method of  claim 1  wherein the fiber has a denier per filament of from 1.0 g/9000 meters to 20.0 g/9000 meters as measured in accordance with ASTM D1907-01.