Influence of raw material and processing characteristics of compressed oil palm residues on manufacturing processes and bending properties of medium-density fiberboard

Abstract The declining availability of rubberwood in Southeast Asia has increased the demand for alternative raw materials for medium-density fiberboard (MDF) production. Oil palm residues are generated in large quantities, but their high moisture content (MC) and heterogeneous characteristics make transportation, storage, and stable processing difficult, necessitating appropriate pretreatment strategies for their effective utilization as MDF raw materials. In this study, compression processing was investigated as a physical pretreatment for oil palm residues. The effects of raw material characteristics prior to compression—namely, MC and chip size distribution—on the properties of compressed materials, energy consumption during the compression and refining processes, and the bending properties of MDF were systematically examined. Oil palm trunk chips were used as the raw material, and compressed materials were produced by controlling the MC and size distribution of the chips before compression. Energy consumption during the compression and refining stages was quantified under various conditions. MDF panels were subsequently manufactured from the obtained fibers, and their modulus of rupture and modulus of elasticity were evaluated. Raw material MC affected the balance of energy consumption between the compression and refining processes, revealing a trade-off between these stages. Refining energy consumption was reduced at 8–11% MC, but bending properties deteriorated, whereas lower total processing energy consumption and stable bending properties were obtained at 14–17% MC. In addition, the size distribution of raw materials influenced the properties of compressed materials and affected processing energy consumption and MDF bending properties. Excessively large chip sizes increased total energy consumption and resulted in reduced bending properties. The findings of this study provide useful insights for establishing MDF manufacturing conditions that balance processing energy efficiency and bending properties through appropriate control of raw material properties in the integrated process of producing compressed oil palm residues and utilizing them as MDF raw materials.