System for control of stickies in recovered and virgin paper processing

Abstract

Enhanced removal and/or control of adhesives or sticky materials, “stickies”, from recovered paper stock or virgin pulp fibers is achieved using a combination of enzyme treatment with adsorbents and/or absorbents. Pulp stock to be treated is typically obtained from old magazines, newspapers, household waste, but may include corrugated boxes and office waste. Virgin pulps may include mechanical, chemical, or semi-chemical pulps. Enzymes typically include hydrolases such as cellulases, hemicellulases, pectinases, amylases, and lipases such as esterases, lyases such as pectate lyases, and oxidoreductases. Adsorbents include activated bentonite, microparticles, talc, clay and modified silica. Absorbents typically include water soluble polymers, dispersants, coagulatants and agglomerants.

1 . A method for enhancing removal of or controlling adhesives and sticky contaminants in paper processing comprising 
 providing or contacting with waste paper or mill process water, in combination,    (a) an effective amount of one or more enzymes to modify or degrade the stickies particles, coatings, fibers or inks and    (b) one or more absorbents or adsorbents to absorb or adsorb to the stickies particles for improved removal or control of sticky contaminants in the paper making process.    
   
   
       2 . The method of  claim 1  wherein the enzymes and absorbents or adsorbents also improve dirt count or brightness.  
   
   
       3 . The method of  claim 1  wherein the enzymes are selected from the group consisting of hydrolases, lyases and oxidoreductases.  
   
   
       4 . The method of  claim 3  wherein the enzymes are selected from the group consisting of cellulases, hemicellulases, amylases, proteases, β-glucosidases, lipases, esterases, pectinases, pectate lyases, laccases, glucose oxidases, and peroxidases.  
   
   
       5 . The method of  claim 1  wherein the individual enzymes or any blends of these enzymes are applied in an amount of between 0.0005% and 0.50% based on air dried fibers, preferably between 0.0025% and 0.25%, and most preferably between 0.05% to 0.15% based on air dried fibers to react with the targeted substrate.  
   
   
       6 . The method of  claim 1  wherein the adsorbents and absorbents are selected from the group consisting of inorganic and organic particles, natural or synthetic.  
   
   
       7 . The method of  claim 1  wherein the adsorbents and absorbents are selected from the group consisting of talc, bentonite, silica, and clay.  
   
   
       8 . The method of  claim 7  wherein the adsorbents or absorbents are activated bentonite having a surface area of greater than 400 m 2 /gram.  
   
   
       9 . The method of  claim 1  wherein the absorbents or adsorbents are in the form of microparticles having particle sizes from 100 nm to 40 microns or specific surface areas from 1 m 2 /g to 2,000 m 2 /g.  
   
   
       10 . The method of  claim 6  wherein the inorganic substances are selected from the group consisting of silicate-linked minerals, carbonate-based minerals, and combinations thereof.  
   
   
       11 . The method of  claim 6  wherein the organic microparticles are selected from the group consisting of cross-linked polymers of cationic, anionic or nonionic nature, having molecular weight from 5,000 to 2,000,000 daltons.  
   
   
       12 . The method of  claim 10  wherein silicate-based minerals are selected from the group consisting of bentonite, montmorillonite, talc, and clay.  
   
   
       13 . The method of  claim 10  wherein carbonate-based minerals are selected from the group consisting of calcium carbonate, magnesium carbonate, and dolomite, natural or synthetically precipitated.  
   
   
       14 . The method of  claim 1  wherein the enzymes are added to the pulper, dump chest, flotation, washer, water treatment, storage chest, machine chest, or other parts of the stock preparation process.  
   
   
       15 . The method of  claim 1  wherein the absorbent or adsorbent are added as a dry powder or as a slurry.  
   
   
       16 . The method of  claim 1  wherein adsorbent or adsorbent is added at a dosage of between 0.005% and 5.0% based on air dried fiber, more preferably between 0.05% and 3.0%, and most preferably between 0.10% and 1.5% based on air dried fiber.  
   
   
       17 . The method of  claim 1  wherein adsorbent or adsorbent is bentonite and is added as a slurry in a concentration of between 0.05% and 10.0%, preferably between 1.0% and 5.0%.  
   
   
       18 . The method of  claim 1  further comprising one or more materials selected from the group consisting of water soluble polymers, dispersants, solvents, suspension aids, fillers, chelants, preservatives, buffers, water, and stabilizers.  
   
   
       19 . The method of  claim 18  wherein the water soluble polymer is a cationic water soluble polymer selected from the group consisting of epichlorohydrin/dimethylamine polymers (EPI-DMA) and cross-linked solutions thereof, polydiallyl dimethyl ammonium chloride (DADMAC), DADMAC/acrylamide copolymers, and ionene polymers.  
   
   
       20 . The method of  claim 18  wherein the material is a water soluble polymer added in a dosage range of from about 0.1 to 1000 ppm, more preferably 1.0 to 100 ppm, and most preferably 2.5 to 10 ppm.  
   
   
       21 . The method of  claim 18  wherein the material is a surfactant selected from the group consisting of soaps, fatty acid alkoxylates, fatty alcohol akloxylates, and EO/PO polymeric surfactants.  
   
   
       22 . A system for enhancing removal of or controlling adhesives and sticky contaminants in paper processing comprising a kit containing an effective amount of a combination of enzymes and absorbent or absorbants to modify or degrade the stickies particles, coatings, fibers or inks.  
   
   
       23 . The system of  claim 22  further comprising instructions on how to treat paper with both enzymes and adsorbents or absorbents.  
   
   
       24 . The system of  claim 22  wherein the enzymes are selected from the group consisting of hydrolases, lyases and oxidoreductases in an amount of between 0.0005% and 0.50% based on air dried fibers, preferably between 0.0025% and 0.25%, and most preferably between 0.05% to 0.15% based on air dried fibers to react with the targeted substrate.  
   
   
       25 . The system of  claim 24  wherein the enzymes are selected from the group consisting of cellulases, hemicellulases, amylases, proteases, β-glucosidases, lipases, esterases, pectinases, pectate lyases, laccases, glucose oxidases, and peroxidases.  
   
   
       26 . The system of  claim 22  wherein the adsorbents and absorbents are selected from the group consisting of inorganic and organic particles, natural or synthetic wherein the absorbents or adsorbents are in the form of microparticles having particle sizes from 100 nm to 40 microns or specific surface areas from 1 m 2 /g to 2,000 m 2 /g.  
   
   
       27 . The system of  claim 26  wherein the adsorbents and absorbents are selected from the group consisting of talc, bentonite, silica, and clay.  
   
   
       28 . The system of  claim 27  wherein the adsorbents or absorbents are activated bentonite having a surface area of greater than 400 m 2 /gram.  
   
   
       29 . The system of  claim 22  wherein the absorbents or adsorbents are selected from the group consisting of silicate-linked minerals, carbonate-based minerals, cross-linked polymers of cationic, anionic or nonionic nature, having molecular weight from 5,000 to 2,000,000 daltons, and combinations thereof.  
   
   
       30 . The system of  claim 29  wherein silicate-based minerals are selected from the group consisting of bentonite, montmorillonite, talc, and clay.  
   
   
       31 . The system of  claim 29  wherein carbonate-based minerals are selected from the group consisting of calcium carbonate, magnesium carbonate, and dolomite, natural or synthetically precipitated.  
   
   
       32 . The system of  claim 22  wherein adsorbent or adsorbent is bentonite and is in a form suitable to add as a slurry in a concentration of between 0.05% and 10.0%, preferably between 1.0% and 5.0%.  
   
   
       33 . The system of  claim 22  further comprising one or more materials selected from the group consisting of water soluble polymers, dispersants, solvents, suspension aids, fillers, chelants, preservatives, buffers, water, and stabilizers.  
   
   
       34 . The system of  claim 33  wherein the water soluble polymer is a cationic water soluble polymer selected from the group consisting of epichlorohydrin/dimethylamine polymers (EPI-DMA) and cross-linked solutions thereof, polydiallyl dimethyl ammonium chloride (DADMAC), DADMAC/acrylamide copolymers, and ionene polymers.  
   
   
       35 . The system of  claim 33  wherein the material is a water soluble polymer added in a dosage range of from about 0.1 to 1000 ppm, more preferably 1.0 to 100 ppm, and most preferably 2.5 to 10 ppm.  
   
   
       36 . The system of  claim 33  wherein the material is a surfactant selected from the group consisting of soaps, fatty acid alkoxylates, fatty alcohol akloxylates, and EO/PO polymeric surfactants.