Observation of anisotropic water movement in Pinus radiata D. Don sapwood above fiber saturation using magnetic resonance micro-imaging

Magnetic resonance micro-imaging has been used to visualise the movement of water during the drying of Pinus radiata D. Don (radiata pine) wood samples of varying annual ring orientation and dimension. The drying process has shown a strong influence of annual ring orientation for thin boards with drying deviating from the classical core-shell model. Diffusion tensor micro-imaging shows the direction of greatest restriction to diffusion being in the transverse radial direction. Similarly, anisotropic values for T-2 relaxation are observed, with values obtained when the transverse face is normal to the static magnetic field being higher than in the case when the radial or tangential faces are normal to the field.