RECENT DEVELOPMENTS IN THE UNDERSTANDING OF WOOD DRYING An Australasian View

The production of solid wood products is increasing in both Australia and New Zealand as plantation timber matures. This review examines recent research aimed at understanding the moisture movement through both soft and hardwoods to provide a sound scientific basis for the improvement of kiln seasoning of timber boards. This work has also provided a means to predict the development of drying stresses from a knowledge of instantaneous and time-dependent strains set up by the moisture-content profiles within the drying boards, and the evaluation of stress-relief strategies. The drying temperatures for collapse-pone timbers are severely bounded, and supervisory models for the control of kiln conditions have been developed. Studies of kiln-wide behaviour have examined the impact of directional switching and maldistribution of the airflow through the stack of boards on the uniformity of drying.