Optimum strategies for pulp fractions refining

Abstract

Abstract Separate refining of pulp fractions before remixing has sometimes been compared to whole pulp refining, with no definitive answer about the interest of doing so. In this work, we present a general method to help decide whether fractions refining can be profitable or not. Recommendations for fractions refining strategies are given, depending on the evolution of pulp properties as a function of applied energy. In the tested case (bleach kraft pulp mix (75 % eucalyptus/25 % radiata pine) fractionated on a 2-stage hydrocyclone process), optimised fractions refining provided a gain of about 40 kWh/T compared to whole pulp mix refining, when targeting a tensile index of 50 N.m/g.