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Holz als Roh- und Werkstoff

, Volume 64, Issue 3, pp 192–197 | Cite as

The water absorption of sapwood and heartwood of Scots pine and Norway spruce heat-treated at 170 °C, 190 °C, 210 °C and 230 °C

  • Sini Metsä-KortelainenEmail author
  • Toni Antikainen
  • Pertti Viitaniemi
ORIGINALARBEITEN ORIGINALS

Abstract

Heat-treatment changes the chemical and physical properties of wood. Wood polymers are degraded, dimensional stability is enhanced, equilibrium moisture content is lowered, colour darkens and biological durability is increased. The properties of heat-treated wood have been researched considerably, but the differences between sapwood and heartwood have not been reported separately. In this research, water absorption differences between sapwood and heartwood of Scots pine and Norway spruce heat-treated at temperatures 170 °C, 190 °C, 210 °C and 230 °C were investigated. The results were compared to industrially kiln-dried reference samples. Water absorption was determined with a floating test based on the EN 927-5 standard. The heartwood of both wood species absorbed less water than sapwood. Heat-treatment evidently decreased the water absorption of spruce and pine heartwood. The higher the heat-treating temperature, the lower the amount of absorbed moisture. However, a very interesting exception was pine sapwood, whose water absorption actually increased with heat-treatment after the three lowest heat-treatment temperatures compared to the reference material. Water absorption did not decrease until the heat-treatment temperature was 230 °C.

Keywords

Water Absorption Wood Species Equilibrium Moisture Content Wood Part Biological Durability 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Wasseraufnahme von Splint- und Kernholz von Kiefer und Fichte nach einer Wärmebehandlung bei 170 °C, 190 °C, 210 °C und 230 °C

Zusammenfassung

Durch Wärmebehandlung werden sowohl die chemischen als auch physikalischen Eigenschaften von Holz verändert. Holzpolymere werden abgebaut, Dimensionsstabilität verbessert, Gleichgewichtsfeuchte verringert, Holz verfärbt sich dunkel und die biologische Dauerhaftigkeit wird erhöht. Die Eigenschaften von wärmebehandeltem Holz wurden zwar umfangreich untersucht, jedoch die Unterschiede zwischen Splint- und Kernholz nicht gesondert dargestellt. In der vorliegenden Studie wurde die unterschiedliche Wasseraufnahme von Splint- und Kernholz von Fichte und Kiefer untersucht, die bei Temperaturen von 170 °C, 190 °C, 210 °C und 230 °C wärmebehandelt wurden. Die Ergebnisse wurden mit technisch getrockneten Proben verglichen. Die Wasseraufnahme wurde mit einer Prüfung nach EN 927-5 bestimmt. Das Kernholz beider Holzarten nahm weniger Wasser auf als das Splintholz. Eine Wärmebehandlung reduzierte ganz offensichtlich die Wasseraufnahme bei Fichten- und Kiefernkernholz. Je höher die Temperatur, desto geringer war die Wasseraufnahme. Allerdings stellt Kiefernsplintholz eine interessante Ausnahme dar, da hier die Wasseraufnahme nach Wärmebehandlung bei den drei ersten Temperaturen gegenüber den Vergleichsproben zunahm. Die Wasseraufnahme nahm erst bei einer Behandlungstemperatur von 230 °C ab.

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Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • Sini Metsä-Kortelainen
    • 1
    Email author
  • Toni Antikainen
    • 2
  • Pertti Viitaniemi
    • 2
  1. 1.VTT Building and TransportVTTFinland
  2. 2.Laboratory of Wood TechnologyHelsinki University of TechnologyTKKFinland

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