Study of Influence on Wood Impregnation Treated with Supercritical CO2 Fluid

Timber of Ochroma lagopus and Bombax malabaricum was treated with supercritical CO2 fluid under different pressure, time duration and temperature conditions, and the weight reduction rate (WRR）and the weight increase rate (WIR) post impregnation of the specimen were determined to explore the influence of technological conditions for supercritical CO2 fluid on the timber impregnation. The results showed that the WIR value of specimen of both tree species treated with supercritical CO2 fluid was greater than that of the control, which indicated that the process of supercritical CO2 fluid treatment could improve the impregnation of the wood. The pressure, temperature and time duration of supercritical CO2 fluid treatment all inlfuenced on WRR and WIR values of the specimen, but the inluence pattern varied. The experiments also showed that when ethanol was added into the supercritical CO2 fluid as entrainer before impregnation treatment, both the WRR and WIR values of the specimen were higher than those of the control.