Variations in the natural density of European oak wood affect thermal degradation during thermal modification

Abstract

Abstract& Key message Thermogravimetric analysis, performed on small samples of earlywood (EW) or latewood (LW), indicated that earlywood is more susceptible to thermal degradation than latewood. These results suggest a direct relationship between wood density (which depends on the EW/LW ratio and indirectly on silviculture) and the response of wood during thermo-modification processes.

Applications of computed tomography (CT) scanning technology in forest research: a timely update and review

“…This degradation can lead to mass loss and a deterioration of its physical and mechanical properties. Coupled with other nondestructive technologies, CT scanning allows the quantification and monitoring of the changes related to degradation (Hervé et al 2014, Hamada et al 2016, Li et al 2016. Its use in wood degradation research is recent but offers a high potential to improve our understanding of the basic physical and biological principles in action (El Hachem et al 2018).…”

“…Heat treatments can improve protection against decay; however, earlywood and latewood have different chemical compositions, which influences thermal degradation (Shchupakivskyy et al 2014). Hamada et al (2016) conducted a study to assess the effect of initial wood density of oak boards on their thermal degradation using X-ray CT scanning (Table 1). From each of five sessile oaks, two boards (250 × 110 × 25 mm 3 ) were radially cut: one close to the pith (inner heartwood) and the other near the sapwood (outer heartwood).…”

“…Before heat treatment, the boards were oven-dried at 103°C for 48 h. Treatment application started and continued at 103°C until mass stabilization, followed by 1 h at 170°C and 2 h at 220°C; the heating rate and gas flow were 1°C•min −1 and 120 mL•min −1 , respectively. Based on the average density values measured from CT scanning data before and after heat treatment, Hamada et al (2016) reported a reduction of wood density after thermal modification equal to about 7% of the initial mass of a board. The authors found important variation inside boards and no clear relationship between initial wood density and the thermo-degradation level.…”

“…Wood degradation can also arise from fungi, especially saprotrophic basidiomycetes. Even though other methods have relied on mechanical and physicochemical properties of wood, mass loss has traditionally been used to quantify the level of degradation, e.g., by Hamada et al (2016). In the case of the biodegradation of European beech wood by the white-rot fungus Phanerochaete chrysosporium, Hervé et al (2014) developed an X-ray CT scanning procedure for fast, nondestructive, and accurate measurement of the density variations of decaying wood.…”

Retificação térmica, termorretificação, tratamento térmico, tratamento com calor ou modificação térmica?

“…Foram encontrados dois artigos em cada uma das seguintes revistas, que foram analisados conjuntamente: Annals of Forest Science, Journal of Materials Science e Wood Science and Technology (ČERMÁK et al, 2016;GÉRARDIN, 2016;HAMADA et al, 2016;RINGMAN et al, 2015; TODOROVIĆ; POPOVIĆ; MILIĆ, 2015; TUKIAINEN; HUGHES, 2016).…”