Mercado, Y., Nunes, L., Cruz-Lopes, L., & Esteves, B. (2024). Heat Treatment of Cryptomeria japonica from Azores. In European Conference on Wood Modification (pp. 27-33). Cham: Springer Nature Switzerland.
Cryptomeria japonica has been introduced to various regions, including the Azores where it is an abundant resource. Its dimensional instability prompts exploration of heat-treatment for property enhancement. Chemical composition analysis involved determination of extractives, lignin, holocellulose, and α-cellulose. Mechanical properties were evaluated for untreated and heat-treated wood samples, including bending strength and stiffness. Shrinking and swelling behavior were assessed through cyclic exposure to extreme moisture conditions. The extractive composition of untreated and heat-treated Cryptomeria wood was analyzed, revealing predominant ethanol, water, and dichloromethane extractives in untreated samples. With heat treatment, a slight increase in ethanol extractives was observed, alike findings in other species. Additionally, the lignin percentage increased post-heat treatment, likely due to hemicellulose degradation and condensation reactions between lignin and polysaccharide degradation compounds. Despite variations in natural durability against subterranean termites, Cryptomeria heartwood remains susceptible to attack. While some antitermic extractives may be removed during heat treatment, no significant change in wood durability against termites was observed. Swelling decreased with heat treatment, particularly in the tangential direction. Mechanical strength, notably bending strength, decreased due to heat treatment, while modulus of elasticity (MOE) initially increased before declining with more severe treatments.
