Gradientes de umidade e suas implicações nas tensões de secagem, quantidade e dimensões de rachaduras na madeira de Eucalyptus tereticornis aos 15 anos

Abstract

The moisture gradient, which corresponds to the humidity difference between the center and the periphery of the piece of wood plays an important role in the development of stresses that cause defects such as cracking, hardening and warping. Care to reduce this difference during and at the end of the drying process are important procedures so that the quality of the wood is not compromised. The present work had as the objective of this study was to evaluate the effect of the moisture gradient on the development of stresses of drying Eucalyptus tereticornis wood conducted in a conventional greenhouse. For 40 x 10 x 70 mm boards were then dried at temperatures of 45ºC, 60ºC and 75ºC, from green to a moisture content of 12%. At the end of the drying, the quality was evaluated. through the moisture gradient, drying stresses and defects. The temperature 75ºC provided shorter drying time, but higher moisture gradients, higher tensions and lower wood quality at the end of drying. The temperatures of 60ºC and 40ºC showed great difference in drying time, but humidity gradients very similar and quality of the fnal material as well. One can then suggest that it be 60ºC for drying Eucalyptus tereticornis wood with gain in time and quality very close to that provided by low temperatures.