Nalco Chemical Company

Jawed M Sarkar

David R Cosper

Hanuman P Didwania

John H Collins

Martha R Finck

Amy M Tseng

A process for enhancing the freeness of paper pulp, which comprises the steps of adding to the pulp from about 0.5 to about 2.5 kilograms per ton based on the dry weight of the pulp, of a cellulolytic enzyme at the vertical tank of the papermaking process, allowing the pulp to contact the cellulolytic enzyme for from about 30 minutes to about 60 minutes, adding at least 0.011%, based on the dry weight of the pulp, of a water soluble cationic polymer, adding at least 0.007%, based on the dry weight of the pulp, of a water soluble anionic polymer and forming the thus treated pulp into paper.

Process for enhancing the freeness of papermaking pulp

A process for improving the freeness of paper pulp, which comprises the steps of adding to the pulp at least 0.05%, based on the dry weight of the pulp, of a cellulolytic enzyme, allowing the pulp to contact the cellulolytic enzyme for from about 40 minutes to about 60 minutes at a temperature of at least 40.degree. C., adding at least 0.011%, based on the dry weight of the pulp, of a water soluble cationic polymer, adding at least 0.007%, based on the dry weight of the pulp, of a water soluble anionic or nonionic polymer and forming the thus treated pulp into paper.

Enzymes in combination with polyelectrolytes for enhancing the freeness

Cationic anionic polyelectrolytes for enhancing the freeness of paper

A process for removing color from a pulp and paper wastewater which comprises the following steps: (a) treating the wastewater with a reducing agent which is capable of inactivating color producing functional groups of the wastewater; and (b) treating the wastewater subsequent to step (a) with a polymer which is capable of removing color from the wastewater.

Treatment of pulp and paper wastewater with reducing agent and a polymer

A method of controlling pitch deposits in a pulp and papermaking process comprising adding lipase and a cationic polymer to a cellulosic slurry in amounts effective for diminishing pitch deposits from the cellulosic slurry in a pulp and/or paper mill. The method may include adding lipase and a cationic polymer to a cellulosic slurry in amounts effective for both reducing the triglyceride content of a cellulosic slurry by hydrolysis and diminishing the concentration of fatty acids released by the hydrolysis in the aqueous phase of a cellulosic slurry. The triglyceride hydrolysate content of the aqueous phase of a cellulosic slurry, formed by the action of lipase on triglyceride within the cellulosic slurry, is reduced when the amount of lipase and the amount of a cationic polymer is maintained for a time period sufficient to hydrolyze at least some of the triglyceride in the cellulosic slurry and reduce the triglyceride hydrolysate in the aqueous phase of the cellulosic slurry.

Method for controlling pitch deposits using lipase and cationic polymer

A process for improving freeness of paper pulp which comprises these steps:

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Naperville, IL, United States of America

Jawed M Sarkar