Veneer, plywood and laminated sections

Plywood production in Australia started in Melbourne in 1911 but the two plants built then closed down after a few years. During the First World War D. G. Brims and Sons Pty. Ltd. established a rotary veneer plant in Brisbane and produced three-ply from hoop pine. Other plants followed, many of them in Queensland which until well after the Second World War produced most of the plywood in Australia, from hoop pine, kauri pine, bunya pine and various rain forest species. In NSW rain forest species were mainly used and in Tasmania, myrtle beech and mountain ash. A plywood plant in Victoria before the Second World War used imported Douglas fir and kauri pine.

The Second World War gave a boost to the industry with the development of improved marine plywood, very thin plywood (individual plies as thin as 0.32 mm) from NSW coachwood for use in Mosquito aircraft and the introduction of plywood from radiata pine in South Australia. Of the eucalypts only low density species such as mountain ash were used commercially at this time although in 1944 some plywood started to be made in Western Australia from karri because of shortage of supplies from the eastern states. Research on plywood peeling, drying and gluing at CSIRO's Division of Forest Products provided useful inputs to some of these innovations.[77]

Because of increasing competition from imported plywood and local hardboards in the 1960s the industry started to move from thin interior products towards heavier and stronger structural products. This led to greater interest in the use of eucalypts and plantation pines and to the development by CSIRO and others of methods for improving gluing behaviour particularly for eucalypts of high density and extractives content.[78]

The plywood industry always supplemented its use of local timbers with imported logs and veneers when it was economically attractive to do so. Imports provided about 50 per cent of its raw material in 1972 but they have since fallen and are now negligible because of price, declining availability and South-east Asia's preference for the export of finished plywood. Fortunately for the industry this trend started when substantial quantities of peeler quality logs were becoming available from local pine plantations and these have now become the main raw material for the production of structural plywood, a development which has been not only technically successful but has also assisted in re-structuring the industry through the establishment of new larger and more efficient mills close to plantation resources.

With the restrictions that have been placed on the logging of rain forest species in recent years and the limited duration imposed on current operations there has been renewed interest in using northern NSW and Queensland eucalypts to make products where appearance as well as strength is important. Considerable progress has been made, although the attainment of a strong waterproof interply bond is still a problem for some dense species with high extractives contents.

Australian Academy of Technological Sciences and Engineering