High HLB non-ionic surfactants for use as deposition control agents

Abstract

Methods are provided for inhibiting and removing contaminants deposited on papermaking parts in papermaking operations, particularly pitch derived from sources of virgin pulp and other contaminants having hydrophobic surfaces, using non-ionic high HLB surfactants.

1 . A method of making paper in a continuous papermaking operation comprising: 
 a) contacting a first pulp suspension that consists essentially of virgin pulp with a first composition comprising a non-ionic high HLB surfactant, wherein: 
 i) said pulp suspension comprises a contaminant; and  
 ii) said surfactant is added in an amount that is sufficient to control deposition of said contaminant onto papermaking parts.  
   
     
     
         2 . The method of  claim 1  further comprising (b) mixing said first pulp suspension with a second pulp suspension that comprises recycled pulp wherein, prior to said mixing step (b), said first pulp suspension is processed in the substantial absence of a second deposition inhibiting agent selected from sequestrants, dispersing agents or surface active agents.  
     
     
         3 . The method of  claim 1  wherein said surfactant has a HLB of from about 12.0 to about 20.0.  
     
     
         4 . The method of  claim 1  wherein the surfactant has a HLB of from 14.2 to 20.0.  
     
     
         5 . The method of  claim 1  wherein the surfactant has a HLB of from 14.0 to 18.1.  
     
     
         6 . The method of  claim 1  wherein said surfactant is represented by the following chemical structure: R—O—(CH 2 CH 2 O) x —H, wherein R is the residue of a C 2-12  alkyl phenol or a C 2-16  linear or branched alcohol, and x is an integer of from about 12 to about 40.  
     
     
         7 . The method of  claim 1  wherein said surfactant is represented by the following chemical structure: HO—(CH 2 CH 2 O) x —(CH(CH 3 )CH 2 O) y (CH 2 CH 2 O) x′ —H, wherein x+x′ is an integer of from about 52 to about 200, and y is an integer of from about 39 to about 68.  
     
     
         8 . The method of  claim 1  wherein the contaminant comprises a mostly hydrophobic surface, and the surfactant is added in an amount sufficient to stabilize said hydrophobic surface.  
     
     
         9 . The method of  claim 1  wherein said contaminant is pitch.  
     
     
         10 . The method of  claim 1 , wherein the surfactant is added in an amount that does not adversely affect the sizing of paper sheet produced from said pulp suspension.  
     
     
         11 . The method of  claim 1 , wherein the surfactant is added in an amount that does not materially increase the water retention of paper sheet produced from said pulp suspension.  
     
     
         12 . The method of  claim 1  wherein said continuous papermaking operation is experiencing excessive pitch deposition in said felt dewatering stage in the absence of said non-ionic high HLB surfactant.  
     
     
         13 . The method of claim I wherein the pulp suspension comprises a cationic demand.  
     
     
         14 . The method of  claim 1  wherein wet strength resins are substantially absent from said pulp suspension.  
     
     
         15 . The method of  claim 1  wherein said first composition consists essentially of said surfactant.  
     
     
         16 . The method of  claim 1  wherein a second deposition control agent is substantially absent from said first composition.  
     
     
         17 . The method of  claim 1  wherein anionic agents are substantially absent from said first composition.  
     
     
         18 . The method of  claim 1  wherein dispersants and organic solvents are substantially absent from said first composition.  
     
     
         19 . The method of  claim 1 , further comprising contacting press felt from said press felt dewatering stage with a second composition that controls contaminant deposition on said press felt.  
     
     
         20 . A method of making paper in a continuous papermaking operation comprising contacting a first pulp suspension with a first composition that consists essentially of a non-ionic high HLB surfactant, wherein: 
 a) said pulp suspension comprises a contaminant; and    b) said surfactant is added in an amount that is sufficient to control deposition of said contaminant onto papermaking parts.    
     
     
         21 . A method of making paper in a continuous papermaking operation comprising contacting a pulp suspension in said papermaking operation with a first composition, wherein: 
 a) said first composition comprises a non-ionic surfactant having a HLB of greater than 14.2;    b) said pulp suspension comprises a contaminant; and    c) said surfactant is added in an amount that is sufficient to inhibit deposition of said contaminant onto papermaking parts.    
     
     
         22 . A method of making paper in a continuous papermaking operation from a pulp suspension comprising: 
 a) providing a continuous papermaking operation that comprises a press felt conditioning stage, wherein: 
 i) the operation is experiencing excessive contaminant deposition in the press felt conditioning stage; and  
 ii) said press felt conditioning stage comprises a showering unit for applying conditioning chemicals to said press felt;  
   b) adding to said showering unit a composition consisting essentially of a non-ionic high HLB surfactant.    
     
     
         23 . A method of making paper in a continuous papermaking operation from a pulp suspension comprising: 
 a) providing a continuous papermaking operation in which parts are contacted by a first decontaminating composition that comprises a high HLB surfactant, wherein the operation experiences excessive pitch deposition in the absence of the first decontaminating composition; and    b) substituting a second decontaminating composition comprising a high HLB surfactant for said first decontaminating composition.