Norway spruce (Picea abies) is widely used not only in Norway but in many other European countries. Due to its refractory behavior after drying it is difficult to impregnate with wood protecting agents that makes it suitable for outside applications. In this research spruce wood samples are exposed to microwave radiation in order to improve the impregnability. The strength properties are evaluated after both microwave and impregnation treatment.
The results show, that microwave treatment on spruce wood samples improves the uptake of impregnation agents. With increasing energy absorption due to microwave radiation the impregnability is improved. No differences could be found between the microwave treatments in radial or tangential direction, neither in uptake of wood preservative nor in strength properties.
The uptake of impregnation agents in spruce wood is increased by using a pre-treatment with microwave radiation. However, some microwave treatments lead to cracks and a reduction in tangential strength. Most of the values of the process parameters used were obviously too high, which resulted in a distinct crack development.
Keywords: Impregnation, microwave treatment, Norway spruce, strength properties
Authors
Andreas Treu
Section Wood Technology, Norwegian Forest and Landscape Institute, Ås, Norway
Simen Gjølsjø
Section Wood Technology, Norwegian Forest and Landscape Institute, Ås, Norway
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