Suitability of Western Australian mallee eucalypt, blue gum and melaleucas

Wood Cement Composites – Suitability of Western Australian mallee eucalypts, blue gum and melaleucas The views expressed and the conclusions reached in this publication are those of the author and not necessarily those of persons consulted. RIRDC shall not be responsible in any way whatsoever to any person who relies in whole or in part on the contents of this report. In submitting this report, the researcher has agreed to RIRDC publishing this material in its edited form. Please note that the Appendices are not included in this report and are available as a hard copy only. Please contact RIRDC for more information. Foreword An ambitious program of tree crop development is taking place throughout the wheat growing zone of Western Australia, coordinated largely by the Department of Conservation and Land Management (CALM) in collaboration with several hundred farmers. Tree crops including mallee eucalypts and melaleucas are being assessed in growth trials and established on farms in conjunction with wheat as a means of tackling the growing problem of salinity and land degradation. The trees planted are expected not only to ameliorate soil salinity by reducing the level of the water table over time but also to provide merchantable products such as leaf oils and wood-based products. Harvesting of fresh leaves from mallee eucalypt and melaleuca trees for leaf oil extraction takes place every three to six years, leaving behind large quantities of small diameter stems as waste which is thought to be suitable for little else apart from biomass fuel. Certain types of reconstituted wood composite panels can utilize such material and it may therefore be possible to convert mallee residues into products such as cement-bonded particulate or flake composite boards. Cement-bonded boards are examined in this project as a potential outlet for such residues because they represent a product with the potential for expansion in Australia. They are made from simple, low cost, inert materials and have high natural resistance to agents that readily destroy solid wood and conventional wood-based composite panels which include termites, fire, borers and rot fungi. Cement-bonded panels are also compatible with smaller-scale, localized manufacturing facilities close to the source of the waste wood residues. The overall aim of this project was therefore to assess the potential suitability of small diameter waste wood from mallee eucalypt and melaleuca trees for the manufacture of wood-cement composites firstly by measuring the compatibility of the wood with …