Optimization of a quality model for CCA industrial impregnation of Pinus radiata D. Don agricultural fencing stakes

Abstract

Impregnation of agricultural fencing stakes (Pinus radiata D. Don) using wood preservative solutions, like chromated copper arsenate (CCA-C), a water soluble salt, to protect them from decay and insect damage was investigated through the method of global modeling. Experiments were conducted using a factorial design with replicates to reduce model variability and to adjust responses to the required technical properties. Levels at which variables must be set were studied: to reduce product variability, to minimize production costs, to desensitize wood regarding the influence of uncontrollable variables, to optimize productive process and to create a global product with a higher intrinsic quality. The proposed model optimizes product retention quality and minimizes product variability, while minimizing preservative's use. Experiments were carried out by controlling wood's humidity, vacuum process duration, time of applying pressure, and preservative solution concentration, in order to allow timber to maintain its anatomical structure unchanged over time. The results of this work may be used in the optimization of similar processes in industrial plants for Pinus radiata D. Don stakes preservation treatments in producing countries.