Preservative technique of three commercially important timber species –
Sissoo (Dalbergia sissoo), Akasmoni (Acacia auriculiformis) and Ghoraneem (Melia azedarach) of Bangladesh
M R Bulbul, M O Hannan, P K Sarker, A A Mahafuz, G N M Ilias
Wood is renewable resource and is widely used as construction material in rural and urban areas of Bangladesh. Dalbergia sissoo, Acacia auriculiformis and Melia azedarach, locally known as Sissoo, Akasmoni and Ghoraneem respectively are three important timber species of Bangladesh. These are used for different purposes normally without preservative treatment. Heartwood of Sissoo, Akasmoni and Ghoraneem are naturally durable but sapwood is not durable. But the presence of sapwood in Sissoo, Akasmoni and Ghoraneem are approximately 43 %, 49 % and 55 % respectively. Discut the use of sapwood of Sissoo, Akasmoni and Ghoraneem might increase the price of wood very high. So it need preservative treatment to increase its durability. Preservative treatment protects them from various biodegradable agents such as fungi and insects. So the study of preservative treatment of the three wood species was undertaken using chromate, copper boron (CCB) preservative by dipping method.
Three important physical properties of wood viz moisture content, density and shrinkage of the species were also studied. Akashmoni showed higher moisture content but lower density than Sissoo. Again Sissoo showed higher density and Akashmoni showed higher shrinkage than the two other wood species. Preservative treatment was carried out with four different preservative concentrations of 4, 5, 6 and 7 % and dipping schedule of 4, 6, 8 and 10 days. It was observed that penetration and retention of CCB was always higher in Sissoo than the two other species which is a clear indication to consider.