Effect of thermal treatment on the physical properties of GG100 clone Eucalyptus wood

Thermal treatment can modify undesirable characteristics of some woods, dimensional instability, and excessive water adsorption. The present research work aimed to assess the effect of thermal treatment on the physical properties of clone GG100 Eucalyptus wood. Wood samples were obtained from 9 year-old trees. Samples were subjected to three types of thermal treatment (T1, T2, and T3). In T1, the wood was kept in a laboratory kiln at 100 degrees C for 180 min. In T2, hydrothermal treatment was performed in an autoclave at 120 degrees C for 120 min. In T3, the combined autoclave and laboratory kiln treatments were employed. The properties evaluated were apparent density (pa); mass loss (ML); longitudinal (beta l), radial (beta r), tangential (beta t), and volumetric shrinkage (beta v); anisotropic factor; and equilibrium moisture content. The treatments caused a decrease of.a and increase of ML. The Equilibrium Moisture Content (EMC) was lowest for T3, and had a negative correlation with ML, beta t, and Delta v. The Pearson correlation analysis indicated the results of the thermal treatments were similar, but T1 presented the lowest variation of the physical properties compared to the other treatments, giving it the best predictability for practical uses.