The performance of treated wood in the field is ultimately affected by retention and penetration of preservative in wood. In the present study, a new preservative system ZiBOC and a commercially used preservative copper-chrome-arsenate (CCA) were used for evaluation of treatability of Melia composita by the vacuum pressure method at different pressure levels in unsealed and end sealed specimens. The retention and penetration levels of both the preservatives were significantly different at (P< 0.05) in sapwood, heartwood and pith zones. Melia composita exhibited treatability class 'C' (21 -42% penetration). The results revealed that longitudinal penetration in Melia composita was the dominant flow as examined by spot test for copper in unsealed and end sealed specimens.

Low permeability of many wood species due to their anatomical properties causes problems during timber drying as well as impregnating with preservatives and resins. Microwave (MW) treatment influences heartwood permeability and improves preservative uptake and distribution. In the present study, microwave treatment of chir pine (Pinus roxburghii) wood was done at 2,45 GHz frequency at different level of intensity and radiation time. The gas permeability of chir pine wood was measured in an in-house built apparatus. Preservative uptake was tested using acid copper chromate (ACC) preservative by a dipping process. The effect of radiation intensity and time on preservative uptake and air permeability were studied. The results revealed remarkable increase in longitudinal wood air permeability and preservative uptake with the increase of intensity and time of treatment. The results indicate that this technology can be tested and applied on pilot scale for application in wood preservation industry.

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This study investigated the effect of microwave treatment on wood pH and termite resistance. Pinus roxburghii heartwood was exposed to four different microwave intensities at 2450 MHz frequency for 5 minutes. Preservative impregnation, pH variation and termite resistance of microwave-treated and control specimens were studied. Wood pH decreased from 4,6 (C1) to 3,9 (T4) and preservative uptake increased (i.e., 10,4 to 21,6 kg.m-3) with increasing microwave treatment intensities. However, microwave treatment had little effect on termite resistance.

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