Application of radio-frequency heating to utility poles. Part 2. Accelerated fixation of chromated copper arsenate

The use of radio-frequency (RF) heating at atmospheric pressure to accelera te the fixation of chromated copper arsenate (CCA) in roundwood was investi gated. This was done using the hexavalent chromium (Cr(VI)) color reaction with chromotropic acid and by analysis of leachable Cr(VI) from sample bori ngs/shavings. The fixation time was greatly reduced by heating the pole sec tions to above 80 degreesC at high humidity. All three wood species used in this study required less than 6 hours to achieve complete fixation of the CCA. This fixation time was further reduced by using the stored heat to com plete the process. Following the RF fixation, the moisture content of the t reated sapwood had been reduced by 50 to 90 percent, although it remained w ell above the fiber-saturation point.