MODEL PREDICTED AND CT SCANNED MOISTURE DISTRIBUTION IN A PINUS-RADIATA BOARD DURING DRYING

Pinus radiata sapwood boards of 100 x 40 x 1200 mm were dried in a tub e dryer at Lule (a) over circle University, using a computer tomograph y (CT) scanner to scan the wood during drying. The CT-scanned wet wood density can illustrate moisture distribution within wood when the woo d basic density profile is known. The CT-scanned results were used to validate a 2-D single board drying model developed at the New Zealand Forest Research Institute. The validation has shown that the model is not only capable of predicting the average moisture content but also m oisture content gradients in board thickness, width and within growth rings. To investigate the effects of sawing pattern and intrinsic wood properties on drying, the input parameters for the model include with in-ring variations of wood density, green moisture content and wood pe rmeability. The model can assist in understanding the causes of some d rying defects and has potential for the development of drying schedule s.