Some factors affecting the whiting-ring internal checking during drying of radiata pine

The internal checking during the industrial drying of radiata pine is studied. The percentage of internal checking is determined and some factors influencing the internal checking are analyzed during the industrial drying at conventional temperatures. The runs are made in a 150 m(3) capacity dry kiln in an industrial plant of the Eighth Region (Chile). The experimental design includes as variables, the origin site of the wood (clay, sand), the wood localization (central-wood, lateral-wood and transition-wood) and the type of cut (radial, tangential and mixed). The results indicate that the percentage of internal checking varies between 1 and 18% and that the origin site of the wood and the wood localization significantly condition the percentage of internal checking during the radiata pine industrial drying at conventional temperatures.