Improving impregnation properties of fir wood to acid copper chromate (ACC) with microwave pre-treatment

Effects of microwave pre-treatment on impregnation properties in fir wood (Abies alba L.) with acid copper chromate (ACC) were studied here. Flat-sawn specimen boards were prepared with moisture content (MC) of 40 +/- 5% and were exposed to microwave radiation with 2450 MHz frequency for 10, 12, 14, and 16 minutes at four different radiation treatments. Microwave-treated specimens, along with the control specimens, were conditioned to the final MC of 12% and then impregnated with 5%-ACC solution, using an empty-cell process. The impregnation properties were then measured, including retention, maximum and minimum depths of penetration, impregnated area in the cross-section, and ACC-leaching. Image J software was used to determine depths of penetration. Results showed that microwave pre-treatment significantly improved all the impregnation properties, with the exception of leaching. Clear direct relation was found between the duration of microwave radiation with the properties. It can be concluded that microwave pre-treatment can be used to significantly improve impregnation properties in fir wood.