INFLUENCE OF HEAT TREATMENT ON THE DEFECTS OF DRYING Hovenia dulcis Thunb. WOOD

This study aimed to evaluate the influence of heat treatments of heating and freezing in the drying defects of Hovenia dulcis Thunb. wood. For this, were used samples from such species of wood concerned with dimensions of 2 x 10 x 20 cm. The heat treatments of heating and freezing were conducted in tank heated to 85oC and in a freezer at -18oC, respectively, where the samples remained during 12 and 24 hours for both treatments. After those pre-treatment, the samples were dried an electric oven with forced air circulation at temperatures of 60 and 90°C until the final moisture content achieves set 0 to 2%. The heat treatments showed different effects in function of defects of drying, While heating and freezing treatments reduced the bending towards the samples which did not suffer any of those treatments, the IRT tended to increase it. For the temperatures of drying, the samples submitted to 60oC showed less pronounced defects, indicating that drying mild drying temperatures decrease the incidence of defects.