Why we microwave wood? High intensity microwave treatment creates changes in wood structure. Inside the wood, microwave energy is converted to heat, creating steam pressure in the wood cells. Ray cells have thinner walls in comparison with the main structural tissues of wood (tracheids, libriform fibres and vessels). Under high internal pressure the thin-walled ray cells rupture to create micro-voids in the radial-longitudinal planes of the wood. These micro-voids form pathways for easy transportation of liquids and vapours
The volume of ray tissue varies between species, ranging from 5-35% of the total wood volume		Tangential-longitudinal section of Radiata pine wood after microwave conditioning

Microwave treatment produces a several thousand fold increase in wood permeability in the radial and longitudinal directions. Our research applications involve adjusting the intensity of microwave energy supplied to control the number of micro-voids, their dimensions and distribution. In this way we create selective microwave modification protocols to suit different applications. We are researching microwave conditioning for relaxation of growth stresses in logs, speeding up hardwood drying, facilitating uptake of preservatives, and generation of wood-resin composite products. We develop technology that can be incorporated into online procedures.

Transverse Section

Tangential-Longitudinal Section