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Title
Identification of factors influencing the maximum flexure of beech wood plasticized by microwave heating
Authors
MIROSLAV GASPARIK and MILAN GAFF
Received
December 4, 2012
Published
Volume 47 Issue 7-8 July-August
Keywords
microwave heating, plasticizing, maximum flexure, moisture content, plasticizing time, orientation,
placement
Abstract
This paper reports on the influence of selected factors and their interactions on maximum flexure after
plasticizing beech wood by microwave heating. To our knowledge, the use of microwave heating has not been
reported for plasticizing wood yet. Therefore, a proper procedure was developed to verify the use of microwave
heating for the purpose of plasticizing. The determination of maximum flexure was based on the principle of
static bending with three-point loading. Maximum flexure was monitored in beech test samples with dimensions
of 25 x 25 x 400 mm (cross-sectional dimensions were selected according to standard testing samples). Samples
were divided into three groups of initial moisture contents of 65%, 30% and 20%. Our research confirmed only
the influence of plasticizing time and moisture content on the maximum flexure of wood plasticized by
microwave heating, exactly as we expected. The other two factors, orientation (radial and tangential) and
placement (in the center or on the side), had small or no effect on the value of maximum flexure. Microwave
heating is quite intense, therefore for this kind of heating, it is better to have higher moisture content in an
appropriate power device and minimal plasticizing time. The biggest advantage of microwave heating is the
short plasticizing time, a few minutes, while steaming requires tens of minutes or even hours.
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