Effect of Thermal Modification on the Physical Properties of Juvenile and Mature Woods of Eucalyptus grandis

Abstract

This study aimed to evaluate the effect of thermal treatment on the physical properties of juvenile and mature woods of Eucalyptus grandis. Boards were taken from 30-year-old E. grandis trees. The boards were thermally modified at 180 °C in the Laboratory of Wood Drying and Preservation at UNESP, Botucatu, Sao Paulo state, Brazil. The results showed that thermal modification caused: (1) decrease of 6.8% in the density at 0% equilibrium moisture content of mature wood; (2) significant decreases of 14.7% and 35.6% in the maximum volumetric swellings of juvenile and mature woods, respectively; (3) significant decreases of 13.7% and 21.3% in the equilibrium moisture content of juvenile and mature woods, respectively. The influence of thermal modification in juvenile wood was lower than in mature wood and caused greater uniformity in the physical variations between these types of wood in E. grandis.

Calorific Value and Chemical Properties in Juvenile and Mature Wood of Thermally-Modified Eucalyptus Grandis

“…The infl uence of thermal treatment was lower on juvenile wood than on mature wood both in terms of calorifi c value and moisture content. Similar behavior was reported by Severo et al (2012) and Calonego et al (2014), who studied the changes of some properties of E. grandis and P. elliotti var. elliottii woods during thermal modifi cation.…”

Effect of the Brazilian process of thermal modification on the physical properties of Eucalyptus grandis juvenile wood

“…Comparing the results to those of a laboratory scale process for the same species and temperatures (140 °C, 160 ° C and 180 °C), smaller reductions were reported by Calonego et al (2012) for both oven-dried (2,1% to 6,7%) and air-dried (0,5% to 4,1%) densities. In some cases, thermal modification had no effect on the oven-dried density of wood at 180 °C (Calonego et al 2014) and even 200 °C (Batista et al 2011). Garcia et al (2012) also reported a smaller reduction in air-dried density (10%) at 180 °C.…”

“…Calonego et al (2012) reported reductions of 8,4%; 14,5% and 23,2% respectively at 140 °C, 160 °C and 180 °C. For 180 °C, Calonego et al (2014) reported reductions of 14,7% and Batista et al (2011) reported 20% reduction for treatments at 200 °C.…”

“…In general, the temperatures applied in these studies are higher, reaching 220 °C and 240 °C (Batista and Klitzke 2010, Batista et al 2011, Cademartori et al 2015, Calonego et al 2012, Garcia et al 2012, because it is easier to control higher temperatures in small devices. Nevertheless, in some of these studies and in the study of Calonego et al (2014), 180 °C was also assessed.…”

Color change and thermogravimetric analysis of thermally treated Eucalyptus grandis wood

“…Based on temperature exposure between 180 ºC and 260 ºC, thermal treatment of wood is an eco-friendly preservation process (HILL, 2006;CADEMARTORI et al, 2014). This method has been recognized also as useful to improve dimensional stability (CALONEGO et al, 2014).…”