Experimental characterization of density, defects and drying kinetic of three amazonian wood species: Astronium lecointei, Dinizia excelsa, and Hymenolobium heterocarpum

Abstract

Drying is an indispensable process for the industrial use of wood because it results in greater stability, durability, quality, and value of the final product. However, pre-established programs for tropical species have been poorly evaluated. The objective of this study was to formulate and evaluate drying programs for tropical species. The woods of Astronium lecointei (muiracatiara), Dinizia excelsa (faveira-ferro) and Hymenolobium heterocarpum (angelim-pedra) were used. The anatomical characteristics and physical properties of these species were evaluated. The drying programs for each wood were elaborated based on the drying potential to estimate the initial and final temperatures. The programs were executed in a laboratory oven with forced air circulation and afterward, the drying rates and defects were evaluated. The highest values of basic density were observed for faveira-ferro (0.92 g cm-³) followed by muiracatiara (0.70 g cm-³), and angelim-pedra (0.59 g cm-³). As for the volumetric shrinkage, the values were increased in the following order: angelim-pedra (9.87%), faveira-ferro (12.70%), and muiracatiara (14.23%). The anisotropy coefficient of the three wood evaluated was less than 1.5. The density and vessel diameter influenced the drying rate of the woods. The application of the drying programs in this work resulted in a high rate of top and surface cracking, which can compromise the use of wood for more demanding purposes. The woods were classified as first-class because the warping did not exceed the allowed limits.