Copper fixation in ACQ-D treated Chinese fir at various temperature and relative humidity conditions
IRG/WP 07-30436
Jinzhen Cao, Lili Yu
In this study, the effect of different conditions of temperature, relative humidity, and duration of post-treatments on accelerating copper fixation in ACQ-D treated Chinese fir wood blocks was investigated. The conditions include the combination of three temperatures (21, 50, and 70?) and two relative humidity levels (20% and 80%), also include four temperatures (50, 70, 90, and 110?) without controlling relative humidity. The results showed that: (1) all post-treatments used in this study can reduce copper leaching from ACQ-D treated wood. The percentage of copper leached out decreased linearly with the duration of post-treatment at a certain temperature and relative humidity condition; (2) temperature has a significant effect on accelerating copper fixation in ACQ-D treated wood. The fixation rate is much higher and the predicted time needed for complete copper fixation is much shorter at higher temperatures; (3) relative humidity has little effect on fixation rate, and has varying effect on predicted time needed for complete fixation. It shows obvious effect at low temperatures and tends to disappear at high temperatures.
Keywords: Chinese fir (Cunninghamia lanceolata Hook.), ACQ-D, copper fixation, temperature, relative humidity, fixation rate