North Carolina State University

John A Heitmann, Jr

Thomas W Joyce

Hou-min Chang

Larry S Jackson

Tien-Wang Wu

A method for making dissolving pulp from cellulosic fiber. The fiber is treated with a 3-stage sequence having a first alkali extraction stage, a xylanase treatment stage, and a second alkali extraction stage. Having the xylanase treatment stage sandwiched between 2 alkali extraction stages results in the dissolving pulp exhibiting both a very low xylan content of about 2.6% by weight or less and a very low mannan content of about 1.5% by weight or less. The low contents of these 2 components cannot be achieved with comparison treatments of only an alkali extraction stage, only a xylanase treatment stage, or only 2 stages of a xylanase treatment stage and an alkali extraction stage.

Method for making dissolving pulp from paper products containing hardwood fibers

A method of treating a felt to remove contaminants therein comprises the steps of providing a felt used in transporting paper webs, preparing an enzyme solution comprising an enzyme selected from the group consisting of a cellulase, a hemicellulase, and mixtures thereof, applying the enzyme solution to the felt for a first predetermined period of time, rinsing the felt with water, applying a solution of sodium hydroxide to the felt to remove the enzyme solution, and rinsing the felt with water to remove the sodium hydroxide solution thereby removing the contaminants in the felt.

Method of cleaning papermaking felts with enzymes

Disclosed is a method of removing ink from xerographically printed paper. The method comprises pulping said printed paper in an aqueous slurry at a non-acidic pH to a consistency of about 8% or less. Next, added to the pulp slurry is a sufficient amount of long chain alcohol, the long chain alcohol having a melting point above room temperature, for a time sufficient with heating at a temperature sufficient, whereby an agglomeration of long chain alcohol and ink particles is formed. Next, the heating is stopped whereby the agglomeration solidifies into particles that settle to the bottom of the pulp slurry. Then, the agglomeration of solidified particles is removed from the pulp slurry thereby leaving a remaining slurry of deinked paper fiber and water. Optionally, the remaining slurry is subjected to flotation to remove substantially any remaining minute ink left particles behind after the agglomeration.

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Raleigh, NC, United States of America

John A Heitmann, Jr