PROPERTIES OF FIBREBOARDS MADE FROM OIL PALM (<em>ELAEIS</em> <em>GUINEENSIS</em>) STEM AND/OR MIXED TROPICAL HARDWOOD SAWMILL RESIDUES

Abstract

The potentials of oil palm (Elaeis guineensis) stem and / or mixed tropical hardwood sawmill residues for making dry-formed resin-bonded medium density fibreboard (MDF) and / or wetformed hardboard were investigated. Chips/fibrous strands of 15 to 25 mm length by 4 to 7 mm thick with variable widths of < 15 mm were digested into pulp using 1.5% NaOH at material:liquor ratio of 1:3.5. The cook lasted 90 min at 25 °C, pH 10.5 and 0.45 MPa. Pulp yields were high (86–88%) and screen rejects were at acceptable levels (1.76–4.11%). Boards were made either as 9.53 mm thick MDF (SG = 0.7, resin content = 7%) or 3.175 mm thick hardboard [SG = 0.8 of either two smooth surfaces (S2S) or screen meshed back (S1S)]. Boards were sampled and conditioned at 20 ± 2 °C and 65 ± 2% relative humidity, and tested in accordance with ASTM D 1037–90. Ten replicates were used for each test for each product. MDF made from tropical hardwood
sawmill residues had higher modulus of rupture (MOR) than those from oil palm or mixed furnish. S2S hardboards had higher MOR and modulus of elasticity (MOE) than S1S. S1S hardboards had higher internal bond than S2S hardboards. The MDF and different hardboards had acceptable properties.