Effect of Log Heat Treatment on Release of Growth Stresses in Eucalyptus Nitens

Abstract

The use of  Eucalyptus nitens  has diversified the Chilean lumber industry in unprecedented ways. However, growth-induced strains cause splitting and warping. The objective of this investigation was to determine the effect of the heat treatment applied to logs of  Eucalyptus niten s on the reduction of growth stresses and improvement of quality in sawn wood. Logs were extracted at different heights of the tree for 15-yr and 20-yr-old trees. The sawmill process was allowed to obtain radial, mixed, and tangential plane pieces, at two thicknesses (25 and 50 mm). The evaluation of MC and warping was according to Chilean National Standards. The results obtained in this research suggest that by applying the heat treatment to  Eucalyptus nitens  logs, a significant reduction in growth strains can be achieved. Heat treatment also increased the quality of the pieces in terms of bow, crooking, and twisting. Therefore, there are substantial benefits of using heat treatments to reduce defects caused by growth strains and thus increase the quality of the wood and reduce its warp.