Thermal stimulated moisture desorption and drying characteristics of tropical hardwoods

The process of thermal stimulated moisture de-sorption and drying characteristics of selected species of tropical hardwoods have been investigated. Empirical equations representing the de sorption by sun drying and oven drying were established. The sun-drying occurred in two phases, the constant rate period and falling rate period. For each phase the drying constants were evaluated and the values ranged from 0.74 to 1.39/h for the constant rate period and from 0.0 to 0.191¯1 for the falling rate period. The moisture diffusion coefficients for sun-drying were determined and the values ranged from 5.0 x 10¯10 to 1.6 x 10¯8/m/s. During the oven drying process, three stages of calculated range between 0.43 to 2.2.17. Triplochiton was found to possess the highest value of shrinkage in confirmation with the high void fraction.