Pulp reactivity enhancement

Abstract

This invention relates to pulp reactivity enhancement. In particular, the invention relates to a method of producing an alkali cellulose which includes steps of providing a pulp and subjecting the pulp to an alkaline treatment to produce the alkali cellulose in the presence of a spacer capable of entering the holes in the interfibrillar spaces of the cellulose fibres. The spacer enters the holes in the interfibrillar spaces of the cellulose fibres, particularly those created by the removal of hemi-cellulose, reducing the tendency for collapse to occur, for example during the subsequent pressing step. Examples of suitable spacers are polyethylene glycols, polyvinyl alcohols and polyacrylates.

1 - 11 . (canceled) 
     
     
         12 . A method of producing an alkali cellulose which includes steps of providing a pulp comprising cellulose fibres containing interfibrillar spaces and subjecting the pulp to an alkaline treatment to produce the alkali cellulose; wherein the alkaline treatment takes place in the presence of a spacer capable of entering the holes in the interfibrillar spaces of the cellulose fibres. 
     
     
         13 . The method as claimed in  claim 12 , wherein the interfibrillar spaces are caused by at least one of:
 activation of the pulp prior to subjecting an activated pulp to the alkaline treatment; and   activation of the pulp during the alkaline treatment of the pulp with 11±3% NaOH.   
     
     
         14 . The method as claimed in  claim 13 , wherein the activation of the pulp is by e-beaming treatment with liquid ammonia or steam explosion. 
     
     
         15 . The method according to  claim 12 , wherein the spacer is a hydrophilic polymer which is soluble or dispersable in an aqueous solution. 
     
     
         16 . The method according to  claim 15 , wherein the water soluble polymer has a molecular weight of 1000 to 2500. 
     
     
         17 . The method according to  claim 16 , wherein the water soluble polymer has a molecular weight of 1250 to 1750. 
     
     
         18 . The method according to  claim 17 , wherein the water soluble polymer has a molecular weight of 1400 to 1600. 
     
     
         19 . The method according to  claim 18 , wherein the water soluble polymer has a molecular weight of about 1500. 
     
     
         20 . The method according to  claim 12 , wherein the spacer is capable of forming hydrogen bridges or ether linkages with the cellulose molecules. 
     
     
         21 . The method according to  claim 20 , wherein the spacer contains a hydrophilic group. 
     
     
         22 . The method according to  claim 21 , wherein the hydrophilic group is a carboxyl, carbonyl or hydroxide group. 
     
     
         23 . The method according to  claim 12 , wherein the spacer is a polyethylene glycol, polyvinyl alcohol or polyacrylate. 
     
     
         24 . The method according to  claim 12 , wherein the amount of spacer used is 0.5% to 2% (m/m) based on the cellulose.