Methods To Control Organic Contaminants In Fibers

Abstract

Methods to control organic contaminants in fibers are described. One method involves contacting the fibers with a) diatomaceous earth and b) detackifier, or an ester hydrolyzing enzyme, or both, for a sufficient time and in a sufficient amount to control the organic contaminants present in the fibers. This method is effective to reduce stickies in paper mill furnish formed with recycled fibers. A method for pitch control in paper mill furnish formed with virgin fibers is also provided. Resulting paper products formed from the processed fibers are also described as well as methods to make them.

What is claimed is: 
     
         1 . A method for controlling deposition of organic contaminants from fibers in paper making systems, comprising contacting said fibers with a) diatomaceous earth and b) at least one detackifier, or at least one ester hydrolyzing enzyme or both, for a sufficient time and in a sufficient amount to control the organic contaminants present in the fibers. 
     
     
         2 . The method of  claim 1 , wherein b) is said at least one ester hydrolyzing enzyme. 
     
     
         3 . The method of  claim 1 , wherein b) is at least one detackifier. 
     
     
         4 . The method of  claim 1 , wherein b) is at least one ester hydrolyzing enzyme and at least one detackifier. 
     
     
         5 . The method of  claim 3 , wherein said diatomaceous earth and detackifier are present together as a liquid suspension and added to a pulp slurry containing said fibers. 
     
     
         6 . The method of  claim 4 , wherein said diatomaceous earth, detackifier, and ester hydrolyzing enzyme are present together in a liquid suspension and added to a pulp slurry containing said fibers. 
     
     
         7 . The method of  claim 2 , wherein said diatomaceous earth and ester hydrolyzing enzyme are present together in a liquid suspension and added to a pulp slurry containing said fibers. 
     
     
         8 . The method of  claim 1 , wherein said diatomaceous earth and b) are added to a pulp slurry containing said fibers prior to a forming stage. 
     
     
         9 . The method of  claim 1 , wherein said organic contaminants comprise synthetic polymers from adhesives, glues, hot-melts, coatings, coating binders, de-inking chemicals, ink residues, wood resins, rosin, contact adhesive binders, unpulped wet strength resins, pitch, or combinations thereof. 
     
     
         10 . The method of  claim 1 , wherein said fibers comprise recycled fibers. 
     
     
         11 . The method of  claim 1 , wherein said organic contaminants comprise stickies. 
     
     
         12 . The method of  claim 1 , wherein the ester hydrolyzing enzyme comprises lipase. 
     
     
         13 . The method of  claim 1 , wherein the at least one detackifier comprises at least one water-soluble cellulose derivative. 
     
     
         14 . The method of  claim 13 , wherein said water-soluble cellulose derivative comprises methyl cellulose, hydroxyl methyl cellulose, hydroxyethyl methyl cellulose, hydropropyl methyl cellulose, cetyl hydroxyethylcellulose or hydroxybutyl methyl cellulose, singly or in any combination thereof. 
     
     
         15 . The method of  claim 1 , wherein said fibers containing organic contaminants comprise fibers from old corrugated containers, old newsprint or old newspapers, mixed office waste, or any combinations thereof. 
     
     
         16 . The method of  claim 1 , wherein the organic contaminants are at least controlled by reducing the amount of organic contaminants present in the fiber. 
     
     
         17 . The method of  claim 1 , wherein the organic contaminants are at least controlled by reducing the size of the organic contaminants present in the fibers. 
     
     
         18 . The method of  claim 1 , wherein the organic contaminants are at least controlled by reducing the tackiness of the organic contaminants present in the fibers. 
     
     
         19 . The method of  claim 1 , wherein said diatomaceous earth, and at least one detackifier and/or at least one ester hydrolyzing enzyme are introduced prior to a pulping stage. 
     
     
         20 . The method of  claim 1 , wherein said diatomaceous earth, and at least one detackifier and/or at least one ester hydrolyzing enzyme are introduced during a pulping stage. 
     
     
         21 . The method of  claim 1 , wherein said diatomaceous earth, and at least one detackifier and/or at least one ester hydrolyzing enzyme are introduced during or right before a stock preparation stage. 
     
     
         22 . The method of  claim 1 , wherein said diatomaceous earth, and at least one detackifier and/or at least one ester hydrolyzing enzyme are introduced after a flotation or a de-inking stage. 
     
     
         23 . The method of  claim 1 , wherein said diatomaceous earth and b) are in contact with the fibers for a time of from about 1 minute to about 8 hours. 
     
     
         24 . The method of  claim 1 , further comprising forming said fibers into paper or paperboard products. 
     
     
         25 . The method of  claim 1 , wherein said diatomaceous earth and b) are introduced prior to the paper machine headbox. 
     
     
         26 . The method of  claim 1 , wherein said diatomaceous earth and b) are introduced in the paper machine white water. 
     
     
         27 . The method of  claim 1 , wherein said fibers comprise virgin fibers, said organic contaminants comprise pitch. 
     
     
         28 . The method of  claim 6 , wherein said liquid suspension further comprises lipoxygenase. 
     
     
         29 . The method of  claim 1 , wherein the ester hydrolyzing enzyme comprises esterase, lipase, or cutinase, singly or in any combination thereof. 
     
     
         30 . The method of  claim 1 , wherein said water-soluble cellulose derivative is a methyl ether cellulose derivative. 
     
     
         31 . A method for controlling organic contaminants from fibers in paper making systems, comprising treating water in a clarifier or immediately prior to said clarifier with a) diatomaceous earth and b) at least one detackifier, or at least one ester hydrolyzing enzyme, or both, for a sufficient time and in a sufficient amount to control the organic contaminants present in said water. 
     
     
         32 . The method of  claim 31 , wherein b) is said at least one ester hydrolyzing enzyme. 
     
     
         33 . The method of  claim 31 , wherein b) is said at least one detackifier, and wherein said diatomaceous earth and detackifier are present together as a liquid suspension and added to said water. 
     
     
         34 . The method of  claim 31 , wherein b) is said at least one detackifier and at least one ester hydrolyzing enzyme, and wherein said diatomaceous earth, detackifier and ester hydrolyzing enzyme are present together in a liquid suspension and added to said water. 
     
     
         35 . The method of  claim 31 , wherein said water further comprises pulp fibers. 
     
     
         36 . The method of  claim 1 , wherein said a) and b) are added separately to said fibers.