High strength paperboard and method of making same

Abstract

A method of making high strength paper or paperboard is provided, comprising the steps of adding a high modulus filler to the aqueous pulp slurry prior and forming the pulp slurry into paper or paperboard. Preferably, the filler is glass fiber that has been coated with a thermosetting resin.

1 . A method of making high strength paper or paperboard comprising the steps of: 
 adding a high modulus filler to an aqueous pulp slurry to form a    modified pulp slurry; and    forming the modified pulp slurry into paper or paperboard.    
   
   
       2 . The method of  claim 1  wherein the filler has a modulus of at least 0.1 GPa.  
   
   
       3 . The method of  claim 1  wherein the filler has a modulus of at least 3 GPa.  
   
   
       4 . The method of  claim 2  wherein the filler is selected from the group consisting of polymers, glass fibers, clay nanoplatelets, carbon fibers, silicon carbide fibers and alumina fibers.  
   
   
       5 . The method of  claim 2  wherein the filler has an aspect ratio of at least 50.  
   
   
       6 . The method of  claim 1  wherein a thermosetting resin is also added to the aqueous pulp slurry prior to the forming step.  
   
   
       7 . The method of  claim 6  wherein the resin has a glass transition temperature higher than the service temperature.  
   
   
       8 . The method of  claim 6  wherein the resin has a glass transition temperature of at least 85 C.  
   
   
       9 . The method of  claim 6  wherein the resin is selected from the group consisting of melamine, PAE, phenolic resins, phenol-formaldehyde, and anionic and cationic polymers.  
   
   
       10 . A paperboard made according to the method of  claim 2 .  
   
   
       11 . A paperboard made according to the method of  claim 3 .  
   
   
       12 . A paperboard made according to the method of  claim 7 .  
   
   
       13 . A paperboard made according to the method of  claim 8 .  
   
   
       14 . A method of making high strength paper or paperboard comprising the steps of: 
 coating a filler with a resin matrix;    adding the coated filler to an aqueous pulp slurry to form a modified    pulp slurry; and    forming the modified pulp slurry into paper or paperboard.    
   
   
       15 . The method of  claim 14  wherein the filler has a modulus of at least 0.1 GPa.  
   
   
       16 . The method of  claim 14  wherein the filler has a modulus of at least 3 GPa.  
   
   
       17 . The method of  claim 16  wherein the filler is glass fiber.  
   
   
       18 . The method of  claim 14  wherein the resin is hydrophilic.  
   
   
       19 . A paper or paperboard made according to the method of  claim 14.