PRODUCTION OF HIGH BRIGHTNESS CEDAR MECHANICAL PULP

摘要

The process of brightening mechanical pulp made from dark species such as western red cedar subjects the pulp to an extraction stage consisting essentially of treatment in an aqueous medium containing caustic at a consistency of between 0.5 and 40% and maintain a temperature between 40 and 100.degree.C for a period of between 10 min and 3 hours to provide an extracted pulp, chelating said pulp and then peroxide bleaching of the pulp to increase its brightness.