Wood is a traditional building material but in general it underlies restrictions in outdoor applications due to its respective durability against microbiological decay. To face this problem, different impregnation systems are applied to enhance the materials’ service life. Scots pine (Pinus sylvestris) is the most widely distributed pine in Eurasia and hence easily available. Despite of the previously defined good treatability of Scots pine sapwood, large differences in treatment performance are reported from industry. As process parameters are always adjusted to the material most difficult to treat, permeability variations in wood material are an economical problem. Therefore, it is important to understand the material in order to make a more reasonable material selection possible.
One can divide three levels influencing the impregnation, when questioning why the treatment result is so different. On the one hand, the procedural as drying schedule, process conditions and treatment agent are affecting the result. On the other hand, indirect properties as site-related factors like light exposure, origin and position in the site and tree related factors as the positioning of the material within the stem contribute. Structural properties as anatomical structures and chemical composition are strongly correlated to permeability by building up the fluid pathway.
In the course of the current PhD project, sample material will be collected from the Nordic and Baltic countries in order to obtain differences in material structure and composition to evaluate patterns in treatment performance according to geographical origin. As a consequence the material will undergo different treatment schemes to indicate permeability differences and locate impregnation pathways to be able to portrait a comprehensive picture of structural mechanisms that influence permeability and retention of impregnation fluids. This enables to better predict material’s treatment properties. Due to this a more reasonable material selection and process schedules will be possible.
Keywords: impregnation pathways, latitude, northern Europe, Scots pine sapwood, treatability
Authors
Zimmer K.
Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, Ås, Norway
Norwegian Forest and Landscape Institute, Ås
Larnøy E.
Norwegian Forest and Landscape Institute, Ås
Høibø O.
Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, Ås, Norway
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