Short notes. COMPARATIVE STUDY OF THE IMPACT OF THERMAL MODIFICATION PARAMETERS ON THE THERMAL CONDUCTIVITY OF DIFFERENTWOOD COMPOSITE PANELS

This study examined how thermal modification influenced the thermal conductivity of plywood, oriented strand board, and medium-density fiberboard. Samples were exposed to two temperature levels, 130°C and 180°C, for 20 and 40 min, while untreated panels were retained as controls. Measurements were carried out under controlled laboratory conditions using the steady-state hot-box method. The thermal modification consistently reduced thermal conductivity across all materials, which suggests improved insulation properties. The observed reductions varied. OSB exhibited the most significant overall decrease in thermal conductivity, while plywood displayed relative stability; conversely, MDF demonstrated a marked reaction under the more rigorous treatment conditions. The type of material used had the most significant overall statistical effect. The duration of the treatment was more important than the temperature. The interaction between temperature and time did not achieve statistical significance within the parameters of the experiment; conversely, interactions involving material type were significant.

Noise Emission and Quality of Surface of Thermally Modified Silver Fir Wood Planed by Horizontal Milling Machine

This study was conducted to provide information regarding to noise emission and the surface quality of silver fir wood (Abies alba Mill.) planed at different feed rates after thermal modification. Four groups of sixteen samples were prepared. One group was used as control and the others were heated at 160°C, 190°C and 220°C, at atmospheric pressure for 3 h. After, all samples were processed along the grain by a planer machine, 3 m/min and 10 m/min feed rates were applied. Noise was measured using a sound level meter, while surface roughness measurements were performed by a stylus profilometer. Higher feed rates produced noticeably higher noise emission as for natural wood as for thermally modified one. The temperature was found to have a modest positive effect on the noise reduction. The increase of temperature and feed rate affected the increase in the surface roughness of the wood. Feed rate resulted as a more significant factor on the noise emission and on the surface roughness than temperature.