The thermal conductivity of fir and beech wood heat treated at 170, 180, 190, 200, and 212°C

Heat treatment changes the chemical, physical, and mechanical properties of wood. The properties of heat-treated wood have been researched considerably, but the thermal conductivity of heat-treated wood in various conditions has not been reported. In this study, the thermal conductivity of heat-treated fir and beech wood at temperatures 170, 180, 190, and 212°C for 2 h with ThermoWood method were investigated. The results were compared with industrially kiln-dried reference samples. The results show that heat treatment caused an important reduction on thermal conductivity of wood, the extend of which is depend upon temperature and wood species. Considering all heat treating temperatures, generally by increasing heat treatment temperature the thermal conductivity of wood decreased. The effect of heat treating temperature on thermal conductivity was identical for fir and beech wood. The highest decrease in thermal conductivity occurred at 212°C for both wood species. When compared with untreated wood, the decreases in thermal conductivity at 170°C, and 212°C for fir and beech wood were 2%, 9 and 2%, 16% respectively. Depending on heat treatment temperature, the decrease found out beech in high temperature is higher than that of fir. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011