Abstract
The effects of initial moisture content (MC) on anti-swelling efficiency (ASE), mass loss (ML), and equilibrium MC (EMC) at 65% relative humidity of thermally modified Scots pine sapwood under saturated steam (TMSA) has been investigated. ML during the TMSA process was higher with the specimens containing moisture before modification compared with initially dry specimens. Surprisingly, the EMC of the modified specimens with initial moisture was higher than that observed with the modified wood that was initially dry before the modification process. Higher initial MC before thermal modification results in a lower ASE.
Technical assistance of MSc Juhani Honkanen, financial support of the Finnish Foundation for Technology Promotion (Tekniikan edistämissäätiö), and the Puumiesten Ammattikasvatussäätiö are gratefully acknowledged.
References
Borrega, M., Kärenlampi, P.P. (2010) Hygroscopicity of heat-treated Norway spruce (Picea abies) wood. Eur. J. Wood Prod. 68:233–235.10.1007/s00107-009-0371-8Search in Google Scholar
Dwianto, W., Takana, F., Inoue, M., Norimoto, M. (1996) Crystallinity changes of wood by heat or steam treatment. Wood Res. 83:47–49.Search in Google Scholar
Esteves, B.M., Domingos, I.J., Pereira, H.M. (2008) Pine wood modification by heat treatment in air. Bioresources 3:142–154.10.15376/biores.3.1.142-154Search in Google Scholar
Hill, C.A.S. Wood Modification – Chemical, Thermal and Other Processes. John Wiley and Sons Ltd., Chichester, UK, 2006.10.1002/0470021748Search in Google Scholar
Hill, C.A.S., Ramsay, J., Keating, B., Laine, K., Rautkari, L., Hughes, M., Constant, B. (2012) The water vapour sorption properties thermally modified and densified wood. J. Mater. Sci. 47:3191–3197.Search in Google Scholar
Metsä-Kortelainen, S., Antikainen, T., Viitaniemi, P. (2006) The water absorption of sapwood and heartwood of Scots pine and Norway spruce heat-treated at 170°C, 190°C, 200°C and 230°C. Holz Roh. Werkst. 64:192–197.10.1007/s00107-005-0063-ySearch in Google Scholar
Phuong, L.X., Takayama, M., Shida, S., Matsumoto, Y., Aoyagi, T. (2007) Determination of the accessible hydroxyl groups in heat-treated Styrax tonkinensis (Pierre) Craib ex Hartwich wood by hydrogen-deuterium exchange and 2H NMR spectroscopy. Holzforschung 61:488–491.10.1515/HF.2007.086Search in Google Scholar
Rautkari, L., Hill, C.A.S., Curling, S., Jalaludin, Z., Ormondroyd, G. (2013) What is the role of the accessibility of wood hydroxyl groups in controlling moisture content? J. Mater. Sci. 48: 6352–6356.Search in Google Scholar
Rowell, R.M., Ellis, W.D. (1978) Determination of dimensional stabilization of wood using the water-soak method. Wood Fiber 10:104–111.Search in Google Scholar
Seborg, R.M., Tarkow, H., Stamm, A. (1953) Effect of heat upon the dimensional stabilization of wood. For. Prod. J. 3:59–67.Search in Google Scholar
Sundqvist, B., Karsson, O., Westermark, U. (2006) Determination of formic-acid concentrations formed during hydrothermal treatment of birch wood and its relation to colour, strength and hardness. Wood Sci. Technol. 40:549–561.10.1007/s00226-006-0071-zSearch in Google Scholar
Torniainen, P., Dagbro, O., Morén, T. (2011) Thermal modification of birch using saturated and superheated steam. In: Proceedings of the 7th Meeting of the Nordic-Baltic Network in Wood Material Science & Engineering (WSE), Oslo, Norway.Search in Google Scholar
Viitaniemi, P., Jämsä, S. (1996) Puun modifiointi lämpökäsittelyllä (Modification of wood with heat treatment). VTT Publications 814, in Finnish, English abstract.Search in Google Scholar
Willems, W. (2009) A novel economic large-scale production technology for high-quality thermally modified wood. In: Proceedings of the 4th European Conference on Wood Modification, Stockholm, Sweden.Search in Google Scholar
©2014 by Walter de Gruyter Berlin/Boston