Abstract
Finnish wood heat treatment technology, ThermoWood, was recently introduced to Québec, Canada by Ohlin Thermo Tech. Subsequently, a large number of initial trials were conducted on five commercially important Québec wood species, spruce (Picea spp.), pine (Pinus spp.), fir (Abies spp.), aspen (Populus spp.), and birch (Betula spp.). These species were thermally-modified in different batches at temperatures of 200 °C or higher. The static bending and hardness of the thermally-modified wood were examined. Decreases of 0% to 49% were observed in modulus of rupture of heat-treated spruce, pine, fir, and aspen depending on species and treatment schedules used; modulus of rupture of birch increased slightly after the heat treatment. The decrease in modulus of elasticity of heat-treated spruce and pine ranged from 4% to 28%; but the modulus of elasticity of heat-treated fir, aspen, and birch increased except one trial for fir. Hardness of the heat-treated wood increased or decreased depending on the species, test directions (radial, tangential, and longitudinal), and treatment schedules.
Zusammenfassung
ThermoWood ist ein aus Finnland stammendes Verfahren zur Wärmebehandlung von Holz, das seit kurzem von Ohlin Thermo Tech in Quebec, Kanada angewendet wird. In diesem Zusammenhang wurden an fünf wirtschaftlich bedeutenden, in Quebec vorkommenden Holzarten, nämlich Fichte (Picea spp.), Kiefer (Pinus spp.), Tanne (Abies spp.), Pappel (Populus spp.) und Birke (Betula spp.), zahlreiche Versuche durchgeführt. Diese Holzarten wurden bei verschiedenen Temperaturstufen von 200 °C oder höher wärmebehandelt, daran anschließend wurden die Biegefestigkeit und Härte des wärmebehandelten Holzes untersucht. Die Biegefestigkeit von wärmebehandelter Fichte, Kiefer, Tanne und Pappel nahm je nach Holzart und Behandlung zwischen 0% und 49% ab; wohingegen die Biegefestigkeit von Birke nach der Behandlung geringfügig höher war. Der Elastizitätsmodul von Fichte und Kiefer nahm zwischen 4 und 28% ab, wohingegen der E-Modul von Tanne, Pappel und Birke mit Ausnahme eines Versuchs bei Tanne zunahm. Die Härte des wärmebehandelten Holzes nahm abhängig von Holzart, Orientierung (radial, tangential und longitudinal) und Behandlung zu oder ab.
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Shi, J.L., Kocaefe, D. & Zhang, J. Mechanical behaviour of Québec wood species heat-treated using ThermoWood process . Holz Roh Werkst 65, 255–259 (2007). https://doi.org/10.1007/s00107-007-0173-9
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DOI: https://doi.org/10.1007/s00107-007-0173-9