International Paper Company

Wayne Christopherson

Thomas E Amidon

Richard B Phillips

Jean J Renard

Linda A Beltz

James A McCann

Craig Forehand

Roger H Purrington

A method wherein waste cellulosic material is used as an alternative fiber source during chemical pulping to replace a fraction of the wood chips. The waste cellulosic material is fed to the digester along with wood chips. The waste cellulosic material need not be repulped or slurried prior to digestion. The wood chips may be any species of hardwood or softwood. Normal chemical pulping charges, temperatures and cooking times applied in the case of 100% wood chip pulping may be used for the co-pulping of waste cellulosic material and wood chips. Thereafter, the pulp is processed as usual for chemical pulping, including the steps of blowing the digester, washing and thickening the brown stock, and bleaching the brown stock under the normal conditions used for the component co-pulped with the waste cellulosic material. Further screening or cleaning steps may be required to remove debris from waste cellulosic material.

Method for co-pulping waste cellulosic material and wood chips

Growing community of inventors

Kaukauna, WI, United States of America

Wayne Christopherson