Drying kinetics and drying quality of spruce wood (Picea abies (L.) Karst.) were investigated at 3 different drying conditions. Drying was performed using a standard procedure with mild, sharp and with oscillatory drying climatic conditions. 25 mm thick side boards were dried till they reached final moisture of 11 %. All procedures were compared by intermittent removal of samples and by measuring the following properties of wood: average moisture content, moisture gradient and casehardening. The final value of the dried wood moisture in all 3 experiments was the same with negligible variations. The maximum moisture content gradient was gained using a drying procedure with the sharp climate, medium by oscillatory climate, and the lowest in the standard program with a mild climate. The casehardening occurred when dried in oscillating and sharp climatic conditions. Rate of casehardening in sharp climate was higher than in the oscillatory climate. The working hypothesis that the oscillating climate enables better drying was not completely confirmed.
|
