Dope for spinning lyocell, method for preparing lyocell filament fiber, and method for preparing lyocell staple fiber using the same

Abstract

This disclose relates to dope for spinning lyocell including cotton linter pulp and an aqueous solution of N-methylmorpholine-N-oxide (NMMO), a method for manufacturing lyocell filament fiber using the dope, lyocell filament fiber manufactured by the method, a method for manufacturing lyocell staple fiber using the dope, and lyocell staple fiber obtained by the manufacturing method. According to the present invention, fiber that exhibits a low orientation degree and fibrillation degree, and a high elongation, and thus may be applied for fiber for high grade clothing, may be provided without conducting additional processes.

1 . A dope for spinning lyocell, comprising:
 cotton linter pulp; and   an aqueous solution of N-methylmorpholine-N-oxide (NMMO).   
     
     
         2 . The dope for spinning lyocell according to  claim 1 , comprising:
 6 to 16 wt % of the cotton linter pulp; and   84 to 94 wt % of the aqueous solution of N-methylmorpholine-N-oxide.   
     
     
         3 . The dope for spinning lyocell according to  claim 1 , wherein the aqueous solution of N-methylmorpholine-N-oxide comprises N-methylmorpholine-N-oxide and water in a weight ratio of 91:9 to 83:17. 
     
     
         4 . The dope for spinning lyocell according to  claim 1 , wherein the cotton linter pulp comprises 99 wt % or more of alpha-cellulose. 
     
     
         5 . A method for manufacturing lyocell filament fiber, comprising: discharging the spinning dope according to  claim 1  from a spinner;
 passing the discharged dope through a coagulation bath to coagulate it into a filament; 
 washing the filament that has passed through the coagulation bath; and 
 drying the washed filament. 
 
     
     
         6 . The method for manufacturing lyocell filament fiber according to  claim 5 , wherein the discharging of the spinning dope from a spinner is conducted at 80 to 130° C. 
     
     
         7 . The method for manufacturing lyocell filament fiber according to  claim 5 , wherein the drying of the washed filament comprises applying tension of 0.1 to 1 g/d to the filament at 80 to 200° C. 
     
     
         8 . Lyocell filament fiber manufactured from the spinning dope according to  claim 1 . 
     
     
         9 . The lyocell filament fiber according to  claim 8 , wherein the lyocell filament fiber has a fibrillation degree above grade 1. 
     
     
         10 . The lyocell filament fiber according to  claim 8 , wherein the lyocell filament fiber has strength of 4 to 8 g/d and an initial modulus of 150 to 230 g/d. 
     
     
         11 . A method for manufacturing lyocell staple fiber, comprising:
 discharging a spinning dope comprising cotton linter pulp and an aqueous solution of N-methylmorpholine-N-oxide (NMMO) from a spinner;   passing the discharged dope through a coagulation bath to coagulate it into a filament;   washing the filament that has passed through the coagulation bath;   drying the washed filament;   crimping the dried filament; and   cutting the crimped filament.   
     
     
         12 . The method for manufacturing lyocell staple fiber according to  claim 11 , wherein the step of crimping includes giving 8˜20/inch of crimps to the filament. 
     
     
         13 . The method for manufacturing lyocell staple fiber according to  claim 11 , wherein the step of cutting includes cutting the filament into a length of 20 to 200 mm. 
     
     
         14 . A lyocell staple fiber manufactured according to  claim 11 , having a length of 20 to 200 mm, and having fibrillation degree above grade 1. 
     
     
         15 . The lyocell staple fiber according to  claim 14 , wherein the lyocell staple fiber has strength of 3 to 8 g/d and elongation at break of 9.5 to 12.0%.