Physical and mechanical properties of thermally modified short-rotation wood in a closed system

ABSTRACT

This work aimed to evaluate the effect of a closed system thermal modification process on some physical and mechanical properties of eucalypt and teak short-rotation wood. We assessed untreated eucalypt and teak (EW and TW) and thermally modified eucalypt and teak wood (TMEW and TMTW). The process was carried out at 160°C for 45 min, and we performed some physical and mechanical tests. Thermal modification reduced the mechanical resistance and hygroscopicity and increased the dimensional stability of wood. The normal density (ρ₁₂) of TMTW was reduced, but no significant effect was verified for TMEW, although it had an absolute reduction of 7%. For both conditions (untreated and thermally modified), teak was more resistant to failure (higher MOR in static bending), and no difference between the species was verified for MOE. Eucalypt wood was more resistant to compression parallel to the grain in both conditions.

KEYWORDS:

• Eucalyptus grandis
• Tectona grandis
• thermal modification
• hygroscopicity
• normal density (ρ₁₂)
• compression parallel to the grain
• static bending
• total swelling
• equilibrium
• moisture content

Acknowledgements

The authors would like to thank the company TWBrazil for donating and thermally modifying the studied material, and the Fundação de Amparo à Pesquisa e Inovação do Espírito Santo (FAPES) for granting a scholarship to the first author.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was funded by the Government of Brazil through the National Council for Scientific and Technological Development (CNPq – Conselho Nacional de Desenvolvimento Científico e Tecnológico) under grant number 476321/2013-1.