Lyocell material with controlled whiteness by hydrogen peroxide treatment and manufacturing method thereof

Abstract

The present disclosure relates to a lyocell material with controlled whiteness by hydrogen peroxide treatment and a manufacturing method thereof, wherein the lyocell material has improved whiteness due to an aging effect through drying and packaging by a predetermined amount of hydrogen peroxide remaining in a tow, and may replace a CA cigarette filter to lower environmental pollution problems caused by discarded cigarette butts, and thus the lyocell material is suitable as a cigarette filter.

1 . A method of manufacturing a lyocell material, the method comprising:
 (S1) spinning a lyocell spinning dope comprising cellulose pulp and an N-methylmorpholine-N-oxide (NMMO) aqueous solution;   (S2) coagulating the lyocell spinning dope spun in the step (S1) to obtain lyocell multi-filaments;   (S3) water-washing the obtained lyocell multi-filaments;   (S4) treating the water-washed lyocell multi-filaments with oil and hydrogen peroxide;   (S5) crimping the lyocell multi-filaments treated with oil and hydrogen peroxide to obtain a crimped tow; and   (S6) drying the crimped tow,   wherein the step (S4) comprises   a process of treating the water-washed lyocell multi-filaments simultaneously with oil and hydrogen peroxide in a bath containing a mixed solution of the oil and hydrogen peroxide with a uniformly maintained concentration, or   a process of treating the water-washed lyocell multi-filaments sequentially in baths respectively containing a single solution of the hydrogen peroxide, and a single solution of oil.   
     
     
         2 . The method of  claim 1 , wherein the hydrogen peroxide in the step (S4) is used to have a concentration maintained in a range of 2 wt % to 6 wt % in the solution for treating the lyocell multi-filaments. 
     
     
         3 . The method of  claim 1 , wherein the oil in the step (S4) is used to have a concentration maintained in a range of 2 wt % to 8 wt % in the solution for treating the lyocell multi-filaments. 
     
     
         4 . The method of  claim 1 , wherein the oil in the step (S4) comprises at least one selected from the group consisting of a lubricating component, a cohesion component, a smoothness component, and a hydrophobic component. 
     
     
         5 . The method of  claim 1 , wherein the drying of the crimped tow in the step (S6) is performed by using a continuous drying device at a temperature of 105° C. to 135° C. for 15 minutes to 45 minutes. 
     
     
         6 . The method of  claim 1 , wherein the coagulating in the step (S2) is performed by supplying cooling air to the spun dope at a temperature of 4° C. to 15° C. and at an airflow rate of 50 L/m 3  to 250 L/m 3 . 
     
     
         7 . The method of  claim 1 , wherein the lyocell spinning dope in the step (S1) comprises 8 wt % to 13 wt % of the cellulose pulp and 87 wt % to 92 wt % of the N-methylmorpholine-N-oxide aqueous solution. 
     
     
         8 . The method of  claim 1 , wherein the cellulose pulp comprises 85 wt % to 99 wt % of alpha-cellulose and has a degree of polymerization (DPw) of 600 to 1700. 
     
     
         9 . The method of  claim 1 , wherein the crimped tow is a lyocell crimped tow including hydrogen peroxide in an amount of 1000 ppm or less. 
     
     
         10 . A lyocell material comprising:
 a crimped tow formed of lyocell multi-filaments spun from a lyocell spinning dope comprising cellulose pulp and an N-methylmorpholine-N-oxide (NMMO) aqueous solution, and treated with oil and bleached with hydrogen peroxide,   wherein the crimped tow comprises a lyocell crimped tow including 1000 ppm or less of hydrogen peroxide and satisfying both a white index of 80 or more and a yellow index of 8 or less.   
     
     
         11 . The lyocell material of  claim 10 , wherein the crimped tow is a lyocell crimped tow including hydrogen peroxide in an amount of 110 ppm or more and 1000 ppm or less and satisfying both a white index of 80 to 90 and a yellow index of 1 to 4. 
     
     
         12 . The lyocell material of  claim 10 , wherein the hydrogen peroxide is used to have a concentration maintained in a range of 2 wt % to 6 wt % in the solution for treating the lyocell multi-filaments during the bleaching. 
     
     
         13 . The lyocell material of  claim 10 , wherein the oil is used to have a concentration maintained in a range of 2 wt % to 8 wt % in the solution for treating the lyocell multi-filaments during the oil treatment. 
     
     
         14 . The lyocell material of  claim 10 , wherein the lyocell spinning dope comprises 8 wt % to 13 wt % of the cellulose pulp and 87 wt % to 92 wt % of the NMMO aqueous solution. 
     
     
         15 . The lyocell material of  claim 14 , wherein the cellulose pulp comprises 85 wt % to 99 wt % of alpha-cellulose and has a degree of polymerization (DPw) of 600 to 1700. 
     
     
         16 . A cigarette filter comprising the lyocell material according to  claim 10 .