Wood Products
Composite Wood Products
The benefit of composite wood products is that small dimensions of timber, which might not be useful as sawn timber, can be utilised to manufacture large dimension composite beams and sheets. This requires less timber overall to make products which can be lighter and stronger than timber.
Production of composite wood products in Australia has increased by more than 70% over the last decade, with the volume of wood panel exports exceeding imports. This is mainly due to a marked increase in the exports of medium density fibreboard, which has become a popular building material around the world.
Some of the popular composite and reconstituted timber products manufactured in Australia include plywood, particleboard, medium density fibreboard, and hardboard.
Plywood is manufactured by gluing together an uneven number of sheets of peeled veneer. The sheets are glued together with the grain in adjacent sheets at right angles. This gives great stability to the sheet and compensates for the large variations in seasonal shrinkage or swelling.
Particleboard is manufactured from industrial logs thinned from Radiata pine plantations and sawmill residues. The logs are flaked to produce a range of different sizes. Resin is added and the boards produced range from large flakes in the core to fine material on the surface. Particleboard is widely used in the furniture and joinery industries, and a high strength waterproof flooring grade is also produced.
Medium density fibreboard (MDF) is manufactured by breaking pine down into individual fibres, then adding resin and compressing it in hot presses. MDF has taken over from particleboard as the major product used in furniture, joinery and mouldings.
Hardboard is made from eucalypt fibre, with the raw material generally sourced from forest thinnings or sawmill off-cuts. Chips are heated with steam and ground up, or heated under pressure. The fibres are suspended in water and fed onto an endless mesh belt where the water is removed by suction. The ribbon of board is then cut to length and stacked in a hot press.
Making plywood veneer products
Photo: SAForestry
