Method of making paper or board

Abstract

Disclosed herein is a mixture comprising at least one carbohydrate-active enzyme, at least one liquid natural polymer, and optionally at least one strength agent. The mixture is useful in methods of making paper or board and methods of improving refinability and/or strengthening potential of paper pulp for use in a paper or board mill. In such methods the mixture is added to a cellulosic material containing pulp slurry in the process of making paper or board products.

1 . A method of making paper or board comprising:
 a) introducing at least one carbohydrate-active enzyme, at least one liquid natural polymer, and optionally at least one strength agent to a once-dried or never-dried pulp slurry prior to refining,   b) refining the treated pulp slurry to form a refined, treated pulp slurry, and   c) forming the refined, treated pulp slurry into paper or board.   
     
     
         2 . The method according to  claim 1 , wherein the treated pulp slurry is refined to a target property selected from the group consisting of: reduced freeness of the refined, treated pulp slurry, increased tensile strength of the paper or board product, increased structural property of the paper or board product, decreased energy required during refining to meet a tensile strength target of a paper or board product, and a combination thereof. 
     
     
         3 . The method according to  claim 1 , wherein the treated pulp slurry is refined to a reduced freeness. 
     
     
         4 . The method according to  claim 2 , wherein the freeness is measured according to the standard Canadian procedure (TAPPI test method T 227 om-99) and is between 30 ml and 890 ml. 
     
     
         5 . The method according to  claim 1 , wherein the treated pulp slurry is refined to an increased tensile strength. 
     
     
         6 . The method according to  claim 2 , wherein the tensile strength is a tensile strength index, which is measured according to TAPPI test method T 220 sp-16, and is between 10 Nm/g and 100 Nm/g. 
     
     
         7 . The method according to  claim 1 , wherein the treated pulp slurry is refined to an increased structural property of the paper or board product. 
     
     
         8 . The method according to  claim 2 , wherein the structural property is the bulk of the paper or board, which is measured according to TAPPI test method T 220 sp-16, and is between 0.1 cm 3 /g and 2.0 cm 3 /g. 
     
     
         9 . The method according to  claim 1 , wherein the at least one carbohydrate-active enzyme and the at least one liquid natural polymer are introduced as two separate addition streams. 
     
     
         10 . The method according to  claim 1 , wherein the at least one carbohydrate-active enzyme and the at least one liquid natural polymer are combined into one suspension before introduced to the pulp slurry. 
     
     
         11 . The method according to  claim 1 , wherein the carbohydrate-active enzyme is a cellulase. 
     
     
         12 . The method according to  claim 1 , wherein the method is used in paper mills or pulp mills, preferably wherein the method is used in a pulp mill in a unit operation in the final brownstock washer, the pulp dryer, the wet stock tower or storage vessel of the paper, the board mill or between these unit operations. 
     
     
         13 . A method of improving at least one property of a pulp slurry for use in a paper or board mill, wherein at least one carbohydrate-active enzyme, at least one liquid natural polymer, and optionally at least one strength agent is introduced to a once-dried or never-dried pulp slurry prior to refining in the paper or board mill, thereby making a treated pulp slurry having at least one improved property. 
     
     
         14 . The method according to  claim 13 , wherein the treated pulp slurry is further refined to further reduce the freeness of the treated the pulps slurry. 
     
     
         15 . The method according to  claim 13  wherein the improved property is one or more properties selected from the group consisting of: reducing freeness of the refined, treated pulp slurry, increasing the tensile strength of a paper or board product made from the treated pulp slurry, increasing the structural property of a paper or board product made from the treated pulp slurry, decreasing the energy required during refining to meet a tensile strength target of a paper or board product, and a combination thereof. 
     
     
         16 . The method according to  claim 1 , wherein the pulp, paper or board is selected from the group consisting of: printing paper, writing paper, corrugating medium, linerboard (kraft and test), tissue, towel, and boxboard. 
     
     
         17 . A method of making a pulp or pulp slurry, comprising:
 a) introducing at least one carbohydrate-active enzyme, at least one liquid natural polymer, and optionally at least one strength agent to a pulp or pulp slurry prior to refining, and   b) refining the treated pulp or pulp slurry to form a refined, treated pulp or pulp slurry.   
     
     
         18 . A method of making paper or board or for making a pulp or pulp slurry, comprising: introducing at least one carbohydrate-active enzyme, at least one liquid natural polymer, and optionally at least one strength agent to a pulp or pulp slurry prior to or after refining to obtain a treated pulp or pulp slurry to form a refined, treated pulp or pulp slurry. 
     
     
         19 . A treated pulp or pulp slurry made by the method according to  claim 1 . 
     
     
         20 . A treated pulp or pulp slurry according to  claim 19  having a freeness, measured according to the standard Canadian procedure (TAPPI test method T 227 om-99), of between 30 ml and 890 ml. 
     
     
         21 . A paper or board product made using the treated pulp slurry according to  claim 1  having a tensile strength, as measured by TAPPI test method T 220 sp-16, of between 10 Nm/g and 100 Nm/g. 
     
     
         22 . A paper or board product made using the treated pulp slurry according to  claim 1  having a bulk, calculated according to TAPPI test method T 220 sp-16, of between 0.1 cm 3 /g and 2.0 cm 3 /g. 
     
     
         23 . The paper or board product according to  claims 21  to  22 , which is selected from the group consisting of: printing paper, writing paper, medium grade paper, paperboard, linerboard, tissue paper, towel paper and moulded packaging. 
     
     
         24 . A mixture comprising at least one carbohydrate-active enzyme and at least one liquid natural polymer, and optionally a strength agent. 
     
     
         25 . A mixture for use in making paper or board comprising at least one carbohydrate-active enzyme and at least one liquid natural polymer, and optionally a strength agent.