Use of hemicellulase composition in mechanical pulp production

Abstract

Methods for reducing energy required for a pulp refining processes by treating a mechanical pulp with a hemicellulase composition are presented. The enzymatic treatment can be carried out at a temperature of from about 10° C. to about 90° C., and/or at a pH of from about 2 to about 10. Paper made from the treated pulp has improved strength over paper made from untreated pulp.

1 . A method for preparing a mechanical pulp, comprising mechanically refining a pulp, wherein during the mechanical refining process the pulp is treated with an enzyme composition comprising a thermostable mannanase.  
     
     
         2 . The method of  claim 1 , wherein the mannanase treatment is carried out at a temperature of 65-95° C.  
     
     
         3 . The method of  claim 1 , wherein the mannanase treatment is carried out at a temperature of 80-90° C.  
     
     
         4 . The method of  claim 1 , wherein the pulp is treated with the combination of a thermostable mannanase and a surfactant.  
     
     
         5 . The method of  claim 4 , wherein the surfactant is a non-ionic surfactant.  
     
     
         6 . The method of  claim 1 , wherein the enzyme composition is substantially free of or free of other enzymes.  
     
     
         7 . The method of  claim 1 , wherein the enzyme composition is substantially free of or free of cellulase enzymes.  
     
     
         8 . The method of  claim 1 , wherein the enzyme composition comprises a thermostable xylanase.  
     
     
         9 . The method of  claim 1 , wherein the enzyme composition consists of a thermostable mannanase.  
     
     
         10 . The method of  claim 1 , wherein the enzyme composition consists essentially of a thermostable mannanase.  
     
     
         11 . The method of  claim 8 , wherein the enzyme composition consists of a thermostable mannanase and a thermostable xylanase.  
     
     
         12 . The method of  claim 8 , wherein the enzyme composition consists essentially of a thermostable mannanase and a thermostable xylanase.  
     
     
         13 . The method of  claim 1 , wherein the mannanase is used in an amount 0.001 mg/g to 10 mg/g of pulp.  
     
     
         14 . The method of  claim 1 , wherein the mechanical refining process is a thermomechanical refining process or chemithermomechanical refining process.  
     
     
         15 . The method of  claim 1 , wherein the pulp is coarse pulp.  
     
     
         16 . The method of  claim 15 , wherein the coarse pulp is once refined or ground pulp, twice refined or ground pulp, reject pulp, long fiber fractions, and combinations thereof.  
     
     
         17 . The method of  claim 15 , wherein the coarse pulp is once refined pulp and/or reject pulp.  
     
     
         18 . The method of  claim 1 , wherein the method further comprises preparing a paper product from the mechanical pulp.  
     
     
         19 - 20 . (Cancelled)  
     
     
         21 . A method for preparing pulp, comprising: 
 providing a pulp source;    converting the pulp source to a pulp;    refining the pulp; and    treating the pulp with a hemicellulase composition,    wherein treating the pulp with the hemicellulase composition occurs during refining of at least a portion of the pulp.    
     
     
         22 . The method of  claim 21 , wherein said refining includes use of at least one refiner, a latency chest, at least one screen, and at least one mixer, and further includes: 
 processing the pulp in the at least one refiner;    holding the processed pulp in the latency chest for a period of time;    screening the processed pulp; and    mixing the processed pulp,    wherein treating the pulp with the hemicellulase composition occurs after processing the pulp.    
     
     
         23 - 65 . (Cancelled)