Effect of Hydro- and Hygro-Thermal Treatments on Some Wood Properties of Pinus Radiata and Pseudotsuga Menziesii

Heat treatments are related to the action of temperature in successive stages and under controlled conditions, changing the chemical structure of wood. However, the method of treatment used may have a significant effect on the properties of the heat treated wood. In order to assess the effect of the heat treatments on the wood properties, two conifer species were considered, as well as the absence of the air through water and vapor and three levels of temperature (130, 145 and 160 °C). The experiments resulted in twelve treatments or interactions plus controls. This study describes the changes in chemical composition of wood at relatively low temperatures and its interactions with the physical and mechanical properties of the new thermally-modified wood. The analysis of the results indicates that the extractives and degradation products that remain in the wood processed in a closed reactor seem to be a very important factor affecting the results.