Efeito do movimento da água no surgimento de rachaduras na seção transversal de toretes de Eucalyptus

Abstract

The arising of defects in logs during the drying process is a major problem in the wood industry. So, knowing how and which those defects arise in the different stages of water loss in wood can be useful for decision making for a more efficient drying. This work aims to evaluate the arising of transversal section cracks on wood logs below and above fiber saturation point. Thirty six logs, with 50cm length each were taken from six Eucalyptus urophyla hybrid trees. The drying was followed until stabilization of the masses and images from the base and top of the logs were taken. We calculated the percentage of area covered by cracks in the base, top, below and above fiber saturation point in each log using digital images and the software NeuroDIC. We found 2,63% of cracks at the equilibrium moisture content and 1,71% until the fiber saturation point, what means 092% of the cracks arose during the free water loss. The base of the logs presented a higher value (2,41%) than the top (1,93%). The results showed that transversal section cracks arise more significantly during free water loss. Besides, cracks from the base of the logs arrives more expressively than in the top. The software NeuroDIC was effective to calculate the percentage of transversal section cracks occurrence.