The effect of wood extractive composition on pitch deposition

A study of the effects that wood extractive composition has on pitch deposition was conducted using model solutions comprised of a resin acid, fatty acid and triglyceride. The deposition behaviour was investigated under various conditions of pH and temperature. Statistical pitch deposition models were developed through the use of general multiple linear regression analysis techniques to relate total pitch deposited to the interaction of the various components present in the pitch before deposition. These statistical models were used to predict suitable control strategies for various pH and temperature conditions. Three of the classes of chemical compounds found in wet end and wood extractive chemistry were investigated in this study. The results and deposition models developed help to explain why strategies to control wood pitch deposition have and/or have not worked. Mechanisms of the interaction between components are proposed, based on evidence from this work and corroboration of papers from the literature. The techniques reported in this thesis form a framework under which more complex and in depth wood pitch deposition studies could be conducted.