Wood pitch fixative evaluation by Laser particle size analysis

Abstract

Wood pitch deposition onto the surface of papermaking machinery continues to be a costly problem. Fixatives - substances said to attach wood resin to wood fibre - have been used to alleviate wood pitch deposition to varying degrees of success. This paper aims to evaluate to what degree fixatives alter the colloidal wood pitch particle size. We were able to show how different wood resin fixatives alter the colloidal wood pitch particle size at three different pH values (4.75, 6.85 and 8.06). The fixatives can be divided into two categories, colloid disrupting and colloid stabilising, according to how they change pitch particle size.