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Density profile and microstructural analysis of densified beech wood (Fagus sylvatica L.) plasticized by microwave treatment

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Abstract

This study was carried out in order to determine the efficacy of microwave (MW) plasticization for wood densification purposes. The plasticization process was carried out using a continuous feed laboratory MW at a frequency of 2.45 GHz. European beech (Fagus sylvatica L.) specimens measuring 50 mm × 40 mm × 8 mm were MW treated (plasticized) with an output of 3.5 kW at a conveyor speed of 0.4 m/min. Afterwards, MW plasticized specimens were densified with a ratio of 50%. Microscopic structure changes of densified wood were detected using a scanning electron microscope (SEM) and density profiles were measured using the X-ray densitography. An average density of 677 kg m−3 and 771 kg m−3 increased significantly to 951 kg m−3 for radially densified and to 1194 kg m−3 for tangentially densified specimens. X-ray densitography results show uniformity of density profiles through specimen thickness, which confirmed the evenly plasticized volume of wood. Microscopic structure observation revealed that the MW plasticization was not accompanied by any fractures, and deformations present in the densified wood were due to viscoelastic buckling of cell walls without crack propagation. Therefore, MW treatment can be considered as an effective method for wood plasticization.

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Acknowledgements

This work was carried out at Research Center Josef Ressel in Brno-Útěchov and financially supported by the Internal Grant Agency (IGA) of the Faculty of Forestry and Wood Technology, Mendel University in Brno, (LDF_PSV_2016015). The authors gratefully acknowledge Thünen Institute of Wood Research for supporting the SEM analysis.

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  1. Department of Wood Science, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 3, 613 00, Brno, Czech Republic

    Jakub Dömény, Petr Čermák, Vojtěch Koiš, Jan Tippner & Radim Rousek

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  1. Jakub Dömény
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  2. Petr Čermák
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  3. Vojtěch Koiš
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  4. Jan Tippner
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  5. Radim Rousek
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Correspondence to Jakub Dömény.

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Dömény, J., Čermák, P., Koiš, V. et al. Density profile and microstructural analysis of densified beech wood (Fagus sylvatica L.) plasticized by microwave treatment. Eur. J. Wood Prod. 76, 105–111 (2018). https://doi.org/10.1007/s00107-017-1173-z

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  • DOI: https://doi.org/10.1007/s00107-017-1173-z

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