Market Pulps Comprising Surface Enhanced Pulp Fibers and Methods of Making the Same

Abstract

A method of making a market pulp can include separating a slurry comprising a plurality of pulp fibers into at least first and second pulp feeds. The first pulp feed can be refined at least by, for each of one or more mechanical refiners, introducing the first pulp feed between two refining elements of the refiner and rotating at least one of the refining elements, each of the refining elements comprising a plurality of bars and a plurality of grooves, where a width of each of the bars is less than or equal to 1.3 mm and a width of each of the grooves is less than or equal to 2.5 mm. The refiner(s) can consume at least 300 kWh per ton of fiber. The refined first pulp feed and second pulp feed, which is not refined, can be combined to produce a third pulp feed that can be dried.

1 . A method of making market pulp, the method comprising:
 separating a slurry that comprises a plurality of pulp fibers into at least a first pulp feed comprising a first plurality of pulp fibers and a second pulp feed comprising a second plurality of pulp fibers;   refining the first pulp feed at least by, for each of one or more mechanical refiners:
 introducing the first pulp feed between two refining elements of the refiner, each of the refining elements comprising:
 a plurality of bars, each protruding from a surface of the refining element and having a width that is less than or equal to 1.3 millimeters (mm); and 
 a plurality of grooves defined by the bars, each having a width that is less than or equal to 2.5 mm; and 
 
 rotating at least one of the refining elements; 
 wherein refining the first pulp feed is performed such that the refiner(s) consume at least 300 kilowatt-hours (kWh) per ton of fiber in the first pulp feed; 
   combining the refined first pulp feed and the second pulp feed to produce a third pulp feed, wherein the second pulp feed is not refined; and   drying the third pulp feed.   
     
     
         2 . The method of  claim 1 , comprising directing the refined first pulp feed into a tank before combining the refined first pulp feed and the second pulp feed. 
     
     
         3 . The method of  claim 1 , wherein refining the first pulp feed is performed such the refiner(s) consume at least 650 kWh per ton of fiber in the first pulp feed. 
     
     
         4 . The method of  claim 1 , wherein refining the first pulp feed is performed such that each of the refiner(s) operates at a specific edge load that is between 0.1 and 0.3 Watt-seconds per meter (W·s/m). 
     
     
         5 . A method of making a market pulp, the method comprising:
 combining first and second pulp feeds to produce a third pulp feed, wherein:
 the first pulp feed comprises a first plurality of pulp fibers having a length weighted average fiber length that is greater than or equal to 0.20 millimeters (mm) and an average hydrodynamic specific surface area that is greater than or equal to 10 square meters per gram (m 2 /g); and 
 the second pulp feed comprises a second plurality of pulp fibers having an average hydrodynamic specific surface area that is less than or equal to 2.0 m 2 /g; and 
   drying the third pulp feed.   
     
     
         6 . The method of  claim 1 , wherein combining the first and second pulp feeds is performed such that less than or equal to 10% of the fibers of the third pulp feed, by weight, are the first pulp fibers. 
     
     
         7 . The method of  claim 1 , wherein the market pulp is made such that the market pulp has a basis weight that is greater than or equal to 500 grams per square meter. 
     
     
         8 . The method of  claim 1 , wherein the first pulp fibers and the second pulp fibers are softwood pulp fibers. 
     
     
         9 . The method of  claim 1 , wherein drying the third pulp feed is performed such that less than or equal to 15% of the market pulp, by weight, is liquid. 
     
     
         10 . The method of  claim 1 , comprising baling the market pulp. 
     
     
         11 . A market pulp comprising:
 a first plurality of pulp fibers having a length weighted average fiber length that is greater than or equal to 0.20 millimeters (mm) and an average hydrodynamic specific surface area that is greater than or equal to 10 square meters per gram (m 2 /g); and   a second plurality of pulp fibers having an average hydrodynamic specific surface area that is less than or equal to 2.0 m 2 /g;   wherein less than or equal to 15% of the market pulp, by weight, is liquid.   
     
     
         12 . The market pulp of  claim 11 , wherein the market pulp has a basis weight that is greater than or equal to 500 grams per square meter. 
     
     
         13 . The market pulp of  claim 11 , wherein less than or equal to 10% of the fibers of the market pulp, by weight, are the first pulp fibers. 
     
     
         14 . The market pulp of  claim 11 , wherein the first pulp fibers and the second pulp fibers are softwood pulp fibers. 
     
     
         15 . A bale of the market pulp of  claim 11 .