Uso of Cyclodextrin for Reducing Yellowing of Pulp and Paper

Abstract

The present invention relates the problem of color formation during paper production resulting in yellowing/brightness reversion of the pulp or the paper. This yellowing/brightness reversion can be reduced by the method of the present invention, which method relates to reducing yellowing of pulp and paper comprising adding or generating cyclodextrin to the pulp before or during washing.

1 - 7 . (canceled)  
   
   
       8 . A method for reducing yellowing of pulp and paper comprising adding to the pulp cyclodextrin or generating a cyclodextrin in the pulp before or during washing of the pulp.  
   
   
       9 . The method according to  claim 8 , wherein the cyclodextrin comprises a α-cyclodextrin.  
   
   
       10 . The method according to  claim 8 , wherein the cyclodextrin comprises a β-cyclodextrin.  
   
   
       11 . The method according to  claim 8 , wherein the cyclodextrin comprises a γ-cyclodextrin.  
   
   
       12 . The method according to  claim 8 , wherein the cyclodextrin is provided by enzymatic generation of cyclodextrin in the pulp.  
   
   
       13 . The method according to  claim 11 , wherein the enzyme comprises CGTase.  
   
   
       14 . The method according to  claim 8 , wherein the method further comprises adding an xylanase to the pulp.