Roller surface

Abstract

The present invention relates to the surface adaptation of a roller to be employed in the production of cellulose filament yarns.

1 . A method of selecting a roller suitable to be used during lyocell filament production, comprising:
 selecting the roller such that a surface of the roller comprises first sections displaying a surface tension so that, depending on a liquid adhering to a filament or yarn, one of the following conditions is fulfilled:   a) surface tension of the first sections is in the range of from 0.25 to 3.5 times the surface tension of the liquid, provided that the surface tension of the liquid is 45 mN/m or more; or   b) the surface tension of the first sections is in the range of from 0.5 to 10 times the surface tension of the liquid, provided that the surface tension of the liquid is less than 45 mN/m.   
     
     
         2 . (canceled) 
     
     
         3 . The method according to  claim 1 , wherein the surface tension of the first sections is so that the following condition is fulfilled: the surface tension of the first sections of condition a) is in the range of from 1 to 1.75 times; the surface tension of the first sections of condition b) is in the range of from 0.9 to 5 times the surface tension of the liquid. 
     
     
         4 . The method according to  claim 1 , wherein the roller surface comprises second sections having a surface tension less than the first sections. 
     
     
         5 . The method according to  claim 1 , wherein the first sections are made from metal. 
     
     
         6 . The method according to  claim 4 , wherein the second sections are made from a synthetic polymer. 
     
     
         7 . The method according to  claim 4 , wherein the second sections are creases or grooves. 
     
     
         8 . The method according to  claim 4 , wherein the roller surface comprises only the first sections or wherein the first sections and the second sections substantially extend parallel along an axis of the roller. 
     
     
         9 . The method according to  claim 4 , wherein the second sections have a breadth of from 0.5 to 5 mm. 
     
     
         10 . The method according to  claim 4 , wherein each of the second sections is spaced apart by 2 to 25 mm. 
     
     
         11 . The method according to  claim 1 , wherein the first sections amount to from 40 to 95% of a surface area of the roller surface. 
     
     
         12 . (canceled) 
     
     
         13 . The method according to  claim 1 , wherein the roller is a guidance roller taking up lyocell filaments or filament bundles after the lyocell filaments or filament bundles exit a coagulation bath. 
     
     
         14 . The method according to  claim 1 , wherein the roller is employed during liquid removal and/or washing. 
     
     
         15 . The method according to  claim 1 , wherein the roller is used during application of additional substances to the filament or yarn. 
     
     
         16 . The method according to  claim 1 , wherein the surface tension of the first sections is in the range of from 0.35 to 2.5 times the surface tension of the liquid, provided that the surface tension of the liquid is 45 mN/m or more. 
     
     
         17 . The method according to  claim 1 , wherein the surface tension of the first sections is in the range of from 0.4 to 0.8 times the surface tension of the liquid, provided that the surface tension of the liquid is 45 mN/m or more. 
     
     
         18 . The method according to  claim 1 , wherein the surface tension of the first sections is in the range of from 0.8 to 2.5 times the surface tension of the liquid, provided that the surface tension of the liquid is less than 45 mN/m. 
     
     
         19 . The method according to  claim 1 , wherein the surface tension of the first sections is in the range of from 1 to 2 times the surface tension of the liquid, provided that the surface tension of the liquid is less than 45 mN/m. 
     
     
         20 . The method according to  claim 5 , wherein the first sections are made from chromium plated steel. 
     
     
         21 . The method according to  claim 4 , wherein the second sections have a breadth of from 1.5 to 2.5 mm. 
     
     
         22 . The method according to  claim 4 , wherein each of the second sections is spaced apart by 3 to 4.5 mm.