Effect of particle geometry on the properties of binderless particleboard manufactured from oil palm trunk

Experimental binderless composite panels were manufactured using fine particles and strands of oil palm (Elaeis guineensis) trunks. Modulus of rupture (MOR), internal bond strength (IB), dimensional stability, and surface roughness of the panels made with a target density of 0.80 g/cm3 were evaluated. Strand type samples had MOR and IB values of 24.95 and 0.95 MPa, respectively. Corresponding values for the fine particle type samples were 4.04 and 0.49 MPa. Panels made from strands met MOR requirement stated in Japanese Industrial Standard (JIS). Enhanced bonding between strands observed by micrographs taken using scanning electron microscopy (SEM) also supported the findings. However, the samples having fine particles had lower MOR values than minimum requirement listed in JIS. Strand type panels had 41.6% thickness swelling which is only 4.6% lower than that of the panels made from fine particles. It appears that dimensional stability of both types of panels exhibited insufficient results according to JIS. Surface roughness quality of the samples made from fine particles had average surface roughness values comparable to those of panels made in past studies. Based on initial results of this work, raw material from oil palm trunks can have some potential to be used to manufacture binderless panels without using any adhesives. This study revealed that mechanical and physical properties of such experimental panels were influenced by the particle geometry. It would be important to consider possible addition of chemical or wax in the particles to improve their dimensional stability in further studies.