Copperized Karanj Seed (Pongamia pinnata) Oil as an Alternative to Chemical Preservative in Plywood Manufacturing

Most chemicals used in wood preservation are toxic to the environment. Use of synthetic preservatives are highly prevalent in plywood manufacture. Wood, which is the basic raw material for plywood manufacture, being ligno-cellulosic material is liable to degradation due to microbiological organisms and other biological wood destroying organisms causing significant loss. Therefore, it is necessary to develop an alternate naturally available preservative which will be effective for plywood manufacture. Karanj or Pongamia pinnata is known for its anti-fungal and pesticide properties that make it an ideal material as wood preservative. Therefore, an attempt was made to develop an eco-friendly green preservative using naturally available plant resources with high toxicity to wood destroying organisms and low toxicity to humans. Copper was incorporated into Karanj seed extractive and 12mm thick plywood samples were prepared at different concentrations 0.5% to 5% of preservative which were subjected to tests for efficacy study and mechanical properties as per Indian Standards. From the results obtained in this study, it can be concluded that 3% concentration of the preservative can be utilized in plywood manufacture which can resist against wood borers and termites. Concentration above 3% of the preservative interfere with the bonding properties of the resin and significantly reduces glue shear strength.