Discolouration of heat-treated fast-growing eucalyptus wood exposed to natural weathering

Abstract

To heat-treat is one of the main alternatives to improve wood performance in outdoor uses. This study aimed to evaluate the discolouration of a heat-treated fast-growing eucalyptus wood exposed to natural weathering tests. Wood samples were cut from a young eucalyptus forest located in Southern Brazil. Thermal treatments were performed in an oven without forced air circulation, according to four combined settings of temperature (i.e. 180 °C and 220 °C) and time (i.e. 3 h and 6 h). The discolouration of the decayed wood was accessed according to the CIELab method. The heat-treatment improved the weathering performance of the eucalyptus wood. Compared to the natural colour of the thermally treated wood, the weathering tests caused fading and greying in its tones. Regarding the treatment parameters, the samples heat-treated during 6 h presented promising results, demonstrating that such treatment may be a useful tool for wood surface protection.