PHYSICAL AND MECHANICAL PROPERTIES OF SALACCA FROND PARTICLEBOARD BONDED WITH EXPIRED CITRIC ACID BINDER

The performance of wood binders in particleboard is diminished by both expiration and improper storage. Those effects on citric acid powder, which is one of potential natural adhesives of particleboard for the future, is still unknown. This research investigated the effect of duration length of citric acid past the expiration and its storage conditions on the properties of Salacca frond particleboard. The effect of its binder content and pressing temperature was also evaluated. One and two-years expired citric acid were used, especially for two-years expired citric acid, two types storage conditions were conducted, namely unexposed to ambient humidity (close-lid container storage) and exposed to ambient humidity (open-lid container storage). The results showed that the water resistance of the particleboard decreased the longer citric acid passed its expiration and aggravated with exposed circumstances (open-lid). Under sufficient binder content and optimal pressing temperature, the mechanical properties of Salacca frond particleboard bonded with expired citric acid were retained in the properties requirement by Japanese Industrial Standard (JIS) A 5908. Expired citric acid still has the potential to be used as a natural binder for particleboard until 2 years passed the expiration. © Forest Research Institute Malaysia