High-Yield Paper and Methods of Making Same

Abstract

A method of making a high-yield paper sheet generally includes blending a pulp mixture including at least about 50 weight percent mechanical pulp, making an uncoated paper sheet from the pulp mixture, applying a surface layer to the paper sheet, the surface layer including nPCC, and drying the sheet, wherein the basis weight of the dried sheet is in the range of about 24 to about 60 pounds.

1 . A method of making a high-yield paper sheet, the method comprising:
 (a) blending a pulp mixture including at least about 50 weight percent mechanical pulp;   (b) making an uncoated paper sheet from the pulp mixture;   (c) applying a surface layer to the paper sheet, the surface layer including nPCC;   (d) drying the sheet, wherein the basis weight of the dried sheet is in the range of about 24 to about 60 pounds.   
   
   
       2 . The method of  claim 1 , wherein the pulp mixture includes at least about weight percent kraft pulp. 
   
   
       3 . The method of  claim 1 , wherein the TMP freeness of the pulp mixture is in the range of about 60 to about 150 CSF. 
   
   
       4 . The method of  claim 1 , wherein the TMP brightness of the pulp mixture is in the range of about 65 to about 80 TAPPI. 
   
   
       5 . The method of  claim 1 , wherein the weight percentage of kraft pulp in the pulp mixture is in the range of about 10 to about 30 weight percent. 
   
   
       6 . The method of  claim 1 , wherein the weight percentage internal PCC ash is in the range of about 8 to about 24 weight percent. 
   
   
       7 . The method of  claim 1 , wherein the sheet is oriented in the MD direction. 
   
   
       8 . The method of  claim 1 , wherein the drying conditions include about 4 to about 12 percent moisture into the size press and about 4 to about 10 percent moisture at the reel. 
   
   
       9 . The method of  claim 1 , wherein the particle size of the nPCC is selected from the group consisting of less than about 200 nanometers, less than about 100 nanometers, and about 15 to about 40 nanometers. 
   
   
       10 . The method of  claim 1 , wherein the nPCC comprises substantially non-agglomerated particles. 
   
   
       11 . The method of  claim 1 , wherein the nPCC has a substantially needle-shaped morphology. 
   
   
       12 . The method of  claim 11 , wherein the needle-shaped nPCC has a diameter in the range of less than about 200 nanometers. 
   
   
       13 . The method of  claim 11 , wherein the needle-shaped NPCC has a length of greater than 1 microns. 
   
   
       14 . The method of  claim 11 , wherein the needle-shaped nPCC has a length of about 4 to about 6 microns. 
   
   
       15 . The method of  claim 1 , wherein the surface layer further includes a pigmentation component selected from the group consisting of GCC, calcined clay, delaminated clay, plastic pigments, silicates, mica, kaolin, bentonite, alumina trihydrate, phyllosilicant, talc, and any combination thereof. 
   
   
       16 . The method of  claim 1 , wherein the surface layer further includes a binder component selected from the group consisting starch, latex, polyvinyl alcohol, carboxymethyl cellulose, glucomannan, protein, and other known binders, and any combination thereof. 
   
   
       17 . A method of making a high-yield paper sheet, the method comprising:
 (a) blending a pulp mixture including at least about 50 weight percent mechanical pulp;   (b) making an uncoated paper sheet from the pulp mixture, wherein the sheet is oriented in the MD direction;   (c) applying a surface layer to the paper sheet, the surface layer including nPCC;   (d) drying the sheet, wherein the basis weight of the dried sheet is in the range of about 35 to about 55 pounds.   
   
   
       18 . A method of making a high-yield paper sheet, the method comprising:
 (a) blending a pulp mixture including at least about 50 weight percent mechanical pulp;   (b) making an uncoated paper sheet from the pulp mixture;   (c) applying a surface layer to the paper sheet, the surface layer including nPCC;   (d) drying the sheet, wherein the basis weight of the dried sheet is less than about 45 pounds, and wherein the drying conditions include about 4 to about 12 percent moisture into the size press and about 4 to about 10 percent moisture at the reel.