Abstract
The decay and termite resistance of boric acid (BA)- and di-sodium octoborate tetrahydrate (DOT)-treated sugi sapwood was tested in the context of additional heat treatments at two temperature levels. Heat treatments had no effect on boron release and almost all boron was leached from specimens during a 10-day weathering period. Decay tests with the brown-rot fungus Fomitopsis palustris and the white-rot fungus Trametes versicolor and a 3-week termite resistance test with the subterranean termite Coptotermes formosanus were performed. Heat treatments did not increase the decay resistance of either BA- or DOT-treated specimens against the brown-rot fungus. However, the decay resistance of BA-treated specimens against the same fungus increased after heat treatment at 220°C for 2 h. Heat treatments at 180°C for 4 h and 220°C for 2 h also resulted in increased decay resistance of DOT-treated specimens against T. versi-color. Increased resistance against termite attack was observed only in DOT-treated specimens heated at 180°C for 4 h or at 220°C for 2 h. Accordingly, a synergistic effect between heat and DOT treatments was observed for resistance against white-rot decay and termites.
References
Awoyemi, L., Westermark, U. (2005) Effects of borate impregnation on the response of wood strength to heat treatment. Wood Sci. Technol.39:484–491.10.1007/s00226-005-0001-5Search in Google Scholar
AWPA standard (1999) A2-98. Standard methods for analysis of waterborne preservatives and fire-retardant formulations.Search in Google Scholar
Boonstra, M., Doelman, P. (1999) Die Eigenschaften von PLATO veredeltem Holz. PLATO veredeltes Holz. PLATO HOUT BV, Arnhem.Search in Google Scholar
DIN standard (1994a) EN 350-1, Natürliche Dauerhaftigkeit von Vollholz; Teil 1: Grundsätze für die Prüfung und Klassifikation der natürlichen Dauerhaftigkeit von Vollholz.Search in Google Scholar
DIN standard (1994b) EN 350-2, Natürliche Dauerhaftigkeit von Vollholz; Teil 2: Leitfaden für die natürliche Dauerhaftigkeit und Tränkbarkeit von ausgewählten Holzarten von besonderer Bedeutung für Europa.Search in Google Scholar
Doi, S., Hanata, K., Kamonji, E., Miyazaki, Y. (2004) Decay and termite durabilities of heat treated wood. In: Proceedings of the 35th Annual Meeting of International Research Group on Wood Protection, 6–10 June 2004, Ljubljana, Slovenia. Document IRG/WP 04-40272. International Research Group on Wood Protection, Stockholm.Search in Google Scholar
Jämsä, S., Viitaniemi, P. (1998) Heat treatment of wood. Better durability without chemicals. In: Nordiske Trebeskyttelsesdager. pp. 47–51.Search in Google Scholar
JIS standard (2004) K 1571, Test methods for determining the effectiveness of wood preservatives and their performance requirements (in Japanese).Search in Google Scholar
JWPA standard (2001) JWPS-TW-P.1, Introduction of wood preservation (in Japanese).Search in Google Scholar
Kamdem, D.P., Pizzi, A., Guyonnet, R., Jermannaud, A. (1999) Durability of heat-treated wood. Document No. IRG/WP 99-40145. International Research Group on Wood Protection, Stockholm.Search in Google Scholar
Kamdem, D.P., Pizzi, A., Jermennaud, A. (2002) Durability of heat-treated wood. Holz Roh Werkst.60:1–6.10.1007/s00107-001-0261-1Search in Google Scholar
Lloyd, J.D. (1997) International status of borate preservative systems. In: Proceedings of the 2nd International Conference on Wood Protection with Diffusible Preservatives and Pesticides. Proceedings No. 7284. Forest Products Society, Madison, WI. pp. 45–54.Search in Google Scholar
Rapp, A.O., Sailer, M., Westin, M. (2000) Innovative Holzvergütung – neue Einsatzbereiche für Holz. In: Tagungsband zur 17. Dreiländer-Holztagung 2000. Schweizerische Arbeitsgemeinschaft für Holzforschung, Zürich. pp. 153–160.Search in Google Scholar
Stamm, A.J. (1956) Thermal degradation of wood and cellulose. Ind. Eng. Chem.48:413–417.10.1021/ie51398a022Search in Google Scholar
Tsunoda, K. (2001) Preservative properties of vapor-boron-treated wood and wood-based composites. J. Wood Sci.47:149–153.10.1007/BF00780565Search in Google Scholar
Wang, Q., Li, J., Winandy, J.E. (2004) Chemical mechanism of fire retardance of boric acid on wood. Wood Sci. Technol.38:375–389.10.1007/s00226-004-0246-4Search in Google Scholar
Welzbacher, C.R., Rapp, A.O. (2005) Durability of heat treated materials from industrial processes in ground contact. In: Proceedings of the 36th Annual Meeting of the International Research Group on Wood Protection, 24–28 April 2005, Bangalore, India. Document No. IRG/WP 05-40312. International Research Group on Wood Protection, Stockholm.Search in Google Scholar
Wienhaus, O. (1999) Modifizierung des Holzes durch eine milde Pyrolyse – abgeleitet aus den allgemeinen Prinzipien der Thermolyse des Holzes. Wiss. Z. Tech. Univ. Dresden48:17–22.Search in Google Scholar
Winandy, J.E. (2001) Thermal degradation of fire-retardant-treated wood: Predicting residual service life. For. Prod. J.51:47–54.Search in Google Scholar
Winandy, J.E., Lebow, P.K. (2001) Modeling strength loss in wood by chemical composition. Part I. An individual component model for southern pine. Wood Fiber Sci.33:239–254.Search in Google Scholar
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