Method and composition for improving fiber quality and process efficiency in mechanical pulping

Abstract

This invention provides a composition and method for improving a mechanical pulping process by decreasing freeness and amount of shives, providing energy and chemical savings, and enhancing brightness and mechanical strength of a paper product made from a pulp material in the process. The composition includes formulations, such as surfactants, chelants, hydrotropes, reductive and oxidative pulp modifiers, and pH-controlling chemicals. The method includes selectively introducing these formulations to the pulp material in the mechanical pulping process.

1 . A composition that improves a mechanical pulping process, said composition comprising:
 (a) an effective amount of a surfactant formulation having one or more surfactants;   (b) an effective amount of a chelant formulation having one or more chelants;   (c) an effective amount of a hydrotrope formulation having one or more hydrotropes;   (d) optionally an effective amount of a reductive pulp modifier formulation having one or more reductive pulp modifiers, or an effective amount of an oxidative pulp modifier formulation having one or more oxidative pulp modifiers; and   (e) optionally an effective amount of one or more pH-controlling chemicals.   
     
     
         2 . The composition of  claim 1 , including about 0.05 weight percent to about 30 weight percent of the surfactant(s). 
     
     
         3 . The composition of  claim 1 , wherein the surfactant formulation includes one or more surfactants selected from the group consisting of: non-ionic surfactants; alkyl alcohol alkoxylates; block polymer alkyl alcohol alkoxylates; ethoxylated tridecyl alcohol; ethoxylated propyloxylated hexadecanol; and combinations thereof. 
     
     
         4 . The composition of  claim 1 , including about 0.05 weight percent to about 50 weight percent of the chelant(s). 
     
     
         5 . The composition of  claim 1 , wherein the chelant formulation includes one or more transitional metal chelants selected from the group consisting of: aminocarboxylates; aminophosphonates; polyphosphates; polyacrylates; organic phosphates; organic phosphonates; phosphates; carboxylic acids; dithiocarbamates; and combinations thereof. 
     
     
         6 . The composition of  claim 1 , including about 0.05 weight percent to about 50 weight percent of the hydrotrope(s). 
     
     
         7 . The composition of  claim 1 , including an about one-to-one or greater weight percent ratio of the hydrotrope to the chelant. 
     
     
         8 . The composition of  claim 1 , including an about two-to-one or greater weight percent ratio of the hydrotrope to the surfactant. 
     
     
         9 . The composition of  claim 1 , wherein the hydrotrope formulation includes one or more hydrotropes selected from the group consisting of: arylenesulfonates; carbohydrates having long-chain aliphatic substituents; and combinations thereof. 
     
     
         10 . The composition of  claim 1 , wherein the hydrotrope formulation includes one or more hydrotropes selected from the group consisting of: xylenesulfonate; cumenesulfonate; toluenesulfonate; and combinations thereof. 
     
     
         11 . The composition of  claim 1 , including about 0.01 to about 50 weight percent of the reductive pulp modifier(s). 
     
     
         12 . The composition of  claim 1 , wherein the reductive pulp modifier formulation includes one or more reductive pulp modifiers selected from the group consisting of: water-soluble inorganic sulfites; bisulfites; metabisulfites; substituted phosphines and tertiary salts thereof; formamidinesulfinic acid and salts and derivatives thereof; formaldehyde bisulfite adduct other aldehyde bisulfite adducts; sulfoxylates; thiosulfates; dithionites; polythionates; sulfinamides and ethers of sulfinic acid; sulfenamides and ethers of sulfenic acid; sulfamides; phosphines; phosphonium salts; phosphites; thiophosphites; and combinations thereof. 
     
     
         13 . The composition of  claim 1 , including about 0.01 weight percent to about 50 weight percent of the oxidative pulp modifier(s). 
     
     
         14 . The composition of  claim 1 , wherein the oxidative pulp modifier formulation includes one or more oxidative pulp modifiers selected from the group consisting of: percarbonates; perborates; hydrogen peroxide; activated hydrogen peroxide; organic peroxyacids and salts thereof; dioxiranes; halogenamines; inorganic peroxides; superoxides and peroxide-superoxides; inorganic peroxyacids and salts thereof; peroxyhydrates; water-soluble organic peroxides; nitrosodisulfonates; hypochlorites; hypobromites; chlorites; chlorates; bromates; perchlorates; chlorine dioxide; chloroamines; chloroamides; chlorosulfamides; bromoamines; bromoamides; bromosulfamides; chlorosulfonic acid; bromosulfonic acid; chlorine; and combinations thereof. 
     
     
         15 . The composition of  claim 1 , including about 5 weight percent to about 90 weight percent of the pH-controlling chemical. 
     
     
         16 . The composition of  claim 1 , including one or more pH-controlling chemicals selected from the group consisting of: trisodium phosphate; sodium metaborate; ammonium carbonate; sodium hydroxide; potassium hydroxide; lithium hydroxide; tetramethylammonium hydroxide; magnesium hydroxide; magnesium carbonate; sodium silicate; sodium carbonate; and combinations thereof. 
     
     
         17 . The composition of  claim 1 , wherein the composition decreases freeness and amount of shives, provides energy and chemical savings, and enhances brightness and mechanical strength of a paper product made from a pulp material in the mechanical pulping process. 
     
     
         18 . A composition that improves a mechanical pulping process, said composition comprising:
 (a) an effective amount of an alkyl alcohol alkoxylate surfactant having formula RO[(CH 2 CHCH 3 O) X (CH 2 CH 2 O) Y ]M; wherein R is C 4  to C 40  straight, branched, or ring alkyl, X is from 1 to about 50, Y is from 0 to about 100, and M is H or an alkali metal;   (b) optionally an effective amount of a chelant formulation having one or more chelants;   (c) optionally an effective amount of a hydrotrope formulation having one or more hydrotropes;   (d) optionally an effective amount of a reductive pulp modifier formulation having one or more reductive pulp modifiers, or an effective amount of an oxidative pulp modifier formulation having one or more oxidative pulp modifiers; and   (e) optionally an effective amount of one or more pH-controlling chemicals.   
     
     
         19 . The composition of  claim 18 , including about 0.05 weight percent to about 99 weight percent of the alkyl alcohol alkoxylate surfactant. 
     
     
         20 . A method of improving a mechanical pulping process, said method comprising:
 (a) contacting a pulp material with a surfactant composition including an effective amount of an alkyl alcohol alkoxylate surfactant having formula RO[(CH 2 CHCH 3 O) X (CH 2 CH 2 O) Y ]M; wherein R is C 4  to C 40  straight, branched, or ring alkyl, X is from 1 to about 50, Y is from 0 to about 100, and M is H or an alkali metal; and   (b) optionally introducing to the pulp material separately from the surfactant composition, as part of the surfactant composition, or with the surfactant composition but not as part of the surfactant composition one or more formulations selected from the group consisting of: one or more additional surfactants; one or more chelants; one or more hydrotropes; one or more reductive pulp modifiers; one or more oxidative pulp modifiers; one or more pH-controlling chemicals; and combinations thereof.   
     
     
         21 . The method of  claim 20 , wherein R is C 8  to C 22  straight, branched, or ring alkyl, X is from 1 to about 20, and Y is from 1 to about 80. 
     
     
         22 . The method of  claim 20 , including contacting the pulp material with about 0.001 weight percent to about 5 weight percent of the alkyl alcohol alkoxylate surfactant, based on oven-dry pulp. 
     
     
         23 . The method of  claim 20 , including introducing to the pulp material about 0.001 weight percent to about 5 weight percent of the hydrotrope(s), based on oven-dry pulp. 
     
     
         24 . The method of  claim 20 , including introducing to the pulp material the hydrotrope formulation as part of the surfactant composition if at least one other optional formulation is introduced to the pulp material as part of the surfactant composition. 
     
     
         25 . The method of  claim 20 , including introducing to the pulp material about 0.005 weight percent to about 5 weight percent of the reductive pulp modifier(s), based on oven-dry pulp. 
     
     
         26 . The method of  claim 20 , including introducing to the pulp material about 0.01 weight percent to about 5 weight percent of the oxidative pulp modifier(s), based on oven-dry pulp. 
     
     
         27 . The method of  claim 20 , including introducing to the pulp material about 0.05 weight percent to about 10 weight percent of the ph-controlling chemical(s), based on oven-dry pulp. 
     
     
         28 . The method of  claim 20 , wherein the pH-controlling chemical includes an alkali and introducing the alkali to the pulp material improves the mechanical strength of the paper product without decreasing the brightness of the paper product. 
     
     
         29 . The method of  claim 20 , including contacting the pulp material with the surfactant composition and introducing to the pulp material one or more of the formulation(s) at the same stage of the mechanical pulping process. 
     
     
         30 . The method of  claim 20 , including simultaneously or sequentially contacting the pulp material with the composition and introducing to the pulp material one or more of the formulation(s). 
     
     
         31 . The method of  claim 20 , wherein contacting the pulp material either prior to refining or during refining. 
     
     
         32 . The method of  claim 20 , wherein the mechanical pulping process is selected from the group consisting of: stone ground wood; pressurized ground wood; refiner mechanical pulp; pressurized refiner mechanical pulp; thermo-refiner mechanical pulp; thermo-mechanical pulp; thermo-chemi-mechanical pulp; thermo-mechanical-chemi pulp; long fiber chemi-mechanical pulp; and chemically treated long fiber. 
     
     
         33 . The method of  claim 20 , wherein the pulp material is selected from the group consisting of: wood chips; mechanical pulp; and combinations thereof. 
     
     
         34 . The method of  claim 20 , including improving the mechanical pulping process by decreasing freeness and amount of shives, providing energy and chemical savings, and enhancing brightness and mechanical strength of a paper product made from the pulp material in the mechanical pulping process.