Termite and decay resistance of particleboard composed of white cypress pine and radiata pine
P D Evans, J W Creffield, J S G Conroy, S C Barry
Phenol-formaldehyde bonded particleboard was manufactured from blends of non-durable radiate pine (P. radiate) and heartwood of the naturally durable species, white cypress pine (C. glaucophylla). Board specimens were subjected to bioassays using two termite species, M. darwiniensis and C. acinaciformis, and the basidiomycete fungi, C. puteana and P. ostreatus, and the durability of specimens was compared with that of commercially manufactured particleboard specimens containing either insecticide or fungicide. The aims were to determine whether the natural durability of the boards was modified by the addition of cypress pine and if the durability of boards was comparable to that of boards containing insecticide or fungicide. Particleboard specimens containing cypress pine showed increased durability compared to specimens consisting entirely of radiate pine. There was an inverse relationship between the percentage of cypress pine and mass losses of specimens during the bioassays. During the M. darwiniensis bioassay mass losses of specimens containing 100 or 90% cypress pine heartwood were comparable to those of specimens containing insecticide. However, cypress pine particleboard specimens, irrespective of cypress pine content, were less resistant to attack by C. acinaciformis than specimens containing insecticide. Specimens containing 75% or more of cypress pine possessed similar decay resistance as specimens containing fungicide.