Influência da posição diametral das tábuas e da vaporização nos defeitos de secagem de Eucalyptus grandis

Abstract

This study evaluated the Eucalyptus grandis drying defects acting on boards diametrical position and on log steaming. Half of the logs, with diameter from 20 to <25, 25 to <30 and 30 to <35cm, were steamed during 20 hours at 90ºC of temperature. Subsequently, the logs (control and steamed) were sawn. The boards were dried in the dry-kiln pilot and the resulting defects from the drying process were measured. The results indicate that: (1) the boards coming from control logs presented different magnitude defects in function of the diametrical position. The split and spring to increase in direction to pith, the bow to increase in direction tobark and cupping were bigger in intermediary boards; (2) the boards coming from steamed logs presented a reduction from drying defects in function of logs diameter and its more homogeneous index in the pith-bark direction.