Machinability of plantation-grown Eucalyptus globoidea timber

Abstract

ABSTRACT Eucalyptus globoidea is an emerging plantation species. Its naturally durable heartwood has the potential to be used for solid wood outdoor products. Good machinability of a timber is essential for solid wood processing but was unknown for E. globoidea. The ASTM D1666 standard was used to assess the machinability of E. globoidea and compared to that of Pinus radiata, the dominating resource for the local wood processing industry and well-known for its good machinability. This study showed that E. globoidea machined equally well or better than P. radiata in planing, boring, mortising, grooving, edging, and turning. Sanding E. globoidea (723 kg/m3) was not possible at the prescribed settings, whereas a smooth finish was obtained for the lower density P. radiata (461 kg/m3). Reducing the sanding depth resulted in a satisfactory sanding finish. Defects that determined the machine scores were identified. When boring, mortising and grooving E. globoidea timber, most defects were chipping caused by the tool exiting the piece. When edging, most care needs to be taken at the corner. The comparable machinability of E. globoidea and P. radiata according to ASTM D1666 indicated that the well-established P. radiata wood processing industry should be able to process E. globoidea.