Impact of Thermal Treatment on Pinus roxburghii Wood

In treated wood specific gravity, moisture content and maximum moisture content was found to be inversely proportional to temperature. There was no significant effect of thermal modification on tracheid length and diameter. The medium texture was observed in all thermally treated and untreated wood samples. The colour becomes darker with increase in temperature. The shrinkage and swelling in all planes decreased with thermal treatment and became dimensionally more stable as compared to control. The cold and hot water soluble extractives content decreased with increase in temperature. Maximum cold and hot water soluble extractives were found at 120°C. The alcohol benzene soluble extractives content were found to increase with increase in temperature. The lignin content increased with temperature. The comparative decrease was found in holocellulose content with lignin. The maximum tensile strength was recorded at 120°C and the maximum bending strength among all treatments was observed in control. The compression parallel to grain was more in thermally treated wood as compare to control, whereas the compression perpendicular to grain was less in thermally treated wood than control.