INFLUENCE OF HEARTWOOD-SAPWOOD PROPORTIONS ON THE DRYING KINETICS OF A BOARD

Several properties have been measured for pinewood samples, correspond ing to the region within the heartwood or the sapwood, with the aim of treating wood as a heterogeneous medium when modelling the drying pro cess. A two driving-force model is used to compare a homogeneous and a heterogeneous approach to the drying of a pinewood board. The main di fference between the two theoretical descriptions is a specific bounda ry condition for the inter-region, which may generate jumps of the moi sture content fields. Experimental and numerical results are presented and some comments are made concerning the use of the heterogeneous mo del.