Adhesive free Melaleuca rhaphiophylla (Swamp Paperbark) bark as an engineered wood product

Abstract

This study investigated the potential for Melaleuca rhaphiophylla bark to be made into a sustainable engineered wood product. Boards were manufactured from M. rhaphiophylla bark by hot pressing them without the use of any additional binders or other chemical treatments. Sheets of bark were pressed for 20 min at temperatures of 90 °C, 120 °C, 150 °C, 180 °C and 195 °C and pressures of 1, 2 and 3 MPa. Samples of the boards underwent three-point bending, water absorption and impedance tube testing to determine their Modulus of Rupture (MoR), Modulus of Elasticity (MoE), thickness swelling, water absorption and sound absorption potential. Linear mixed effects (LME) models were used to identify correlations between the condition of the bark and hot-pressing parameters with the properties of the final boards. The MoR, MoE and thickness swelling properties of the boards were found to be similar or superior to other bark-based alternatives. Water absorption was similar to commercially available plywood and medium density fibreboard (MDF) control materials, sound absorption was higher, but MoR and MoE were lower. M. rhaphiophylla bark boards show potential to be suitable alternatives for medium density fibreboard and plywood including uses in cabinetry or veneers with further development.