CARACTERIZACIÓN DEL COLAPSO EN MADERA ASERRADA DE Euca/yptus globu/us Labill.

Abstract

The drying of Eucalyptus wood is one of the main problems to use it far furniture, floors, veneer and other products, because of its permeability and high tendency to attain abnormal shrinkage known as "collapse". In arder to assess and describe the drying process of Euca/yptus g/obu/us wood, an experiment was conducted at the Instituto de Tecnología de Productos Forestales of the Universidad Austral de Chile. Wood samples of E. globulus were collected from trees planted in Northern Valdivia, Chile. Fifty boards of 30 x 120 x 1100 mm were sawn at 24 mm, anc were submitted to conventional drying in a metallic Hildebrand kiln of 0.1888 m3 capacity, at an initial temperature of 50º C. During the drying process a collapse in the wood was observed, representing it more than 30% of wood moisture content. This value is considered the saturation point of the fiber and represents 60.1 % of the total value of volumetric shrinkage. The collapse in Eucalyptus wood was observed as a depletion of the fiber cell walls in the radial face, which produced few depressions and a corrugated surface. lt was concluded that there is not clear relationship between the collapse index with the initial moisture content and basic density.