High Yield and Enhanced Performance Fiber

Abstract

A method for wood pulping including chemically pulping wood chips to a kappa number sufficient to generate a first amount of pulp including a first accepts component and 6 to 50 percent by weight of the first amount of pulp of a first rejects component, separating the first accepts component from the first rejects component, performing a high consistency, substantially mechanical pulping of the first rejects component to generate a second amount of pulp including a second accepts component and a second rejects component, and separating the second accepts component from the second rejects component.

What is claimed is: 
     
         1 . A method for wood pulping comprising steps of:
 (a) chemically pulping wood chips to a kappa number sufficient to generate a first amount of pulp including a first accepts component and 6 to 50 percent by weight of the first amount of pulp of a first rejects component;   (b) separating the first accepts component from the first rejects component;   (c) performing a high consistency, substantially mechanical pulping of the first rejects component to generate a second amount of pulp including a second accepts component and a second rejects component; and   (d) separating the second accepts component from the second rejects component.   
     
     
         2 . The method of  claim 1  wherein the chemical pulping in step (a) comprises at least one of kraft pulping, soda pulping and sulfite pulping. 
     
     
         3 . The method of  claim 1  wherein the first rejects component comprises about 30 to about 35 percent by weight of the first amount of pulp. 
     
     
         4 . The method of  claim 1  wherein the separating step in step (b) comprises a step of passing the first amount of pulp through a screen to separate the first accepts component from the first rejects component. 
     
     
         5 . The method of  claim 1  wherein the high consistency, substantially mechanical pulping comprises a pulping process selected from the group consisting of mechanical pulping, alkaline peroxide mechanical pulping, alkaline thermomechanical pulping, thermomechanical pulping, and chemi-thermomechanical pulping. 
     
     
         6 . The method of  claim 1  wherein the high consistency, substantially mechanical pulping comprises the steps of:
 refining the first rejects component; and 
 pre-bleaching the first rejects component. 
 
     
     
         7 . The method of  claim 1  wherein the high consistency, substantially mechanical pulping comprises the steps of:
 refining the first rejects component; 
 pre-bleaching the first rejects component; and 
 retaining the first rejects component treated at the refining and the pre-bleaching steps for a predetermined time period. 
 
     
     
         8 . The method of  claim 1  wherein the separating step in step (d) comprises a step of passing the second amount of pulp through a screen to separate the second accepts component from the second rejects component. 
     
     
         9 . The method of  claim 1  further comprising a step of combining the second rejects component with the first rejects component before further processing. 
     
     
         10 . The method of  claim 1  further comprising a step of combining the second accepts component with the first accepts component to generate a fiber blend. 
     
     
         11 . The method of  claim 10  wherein the fiber blend includes a first weight associated therewith, wherein the first accepts component includes a first weight associated therewith, and wherein the ratio of the first weight of the first accepts component to the first weight of the fiber blend comprises about 50% to about 90%. 
     
     
         12 . The method of  claim 10  wherein the wood chips have a weight associated therewith, wherein the fiber blend has a weight associated therewith, and wherein the weight of the fiber blend is at least 45% of the weight of the wood chips. 
     
     
         13 . The method of  claim 10  further comprising a step of bleaching the fiber blend. 
     
     
         14 . The method of  claim 1  wherein the wood chips comprise hardwood chips, and wherein the chemically pulping step is performed to a kappa number of at least 30. 
     
     
         15 . The method of  claim 1  wherein the chemically pulping step is performed to a kappa number of at least 50. 
     
     
         16 . A method for wood pulping comprising steps of:
 (a) chemically pulping wood chips to a kappa number sufficient to generate a first amount of pulp including a first accepts component and more than 30 percent by weight of the first amount of pulp of a first rejects component;   (b) separating the first accepts component from the first rejects component;   (c) performing a high consistency, substantially mechanical pulping of the first rejects component to generate a second amount of pulp including a second accepts component and a second rejects component; and   (d) separating the second accepts component from the second rejects component.   
     
     
         17 . The method of  claim 16  further comprising a step of combining the second accepts component with the first accepts component to generate a fiber blend. 
     
     
         18 . The method of  claim 17  further comprising a step of bleaching the fiber blend. 
     
     
         19 . The method of  claim 16  wherein the wood chips comprise hardwood chips, and wherein the chemically pulping step is performed to a kappa number of at least 30. 
     
     
         20 . The method of  claim 16  wherein the chemically pulping step is performed to a kappa number of at least 50.