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Microstructure of viscoelastic thermal compressed (VTC) wood using computed microtomography

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Abstract

The paper describes for the first time the analysis of the structure of compressed wood using computed tomography. The anatomical structures of Douglas-fir and hybrid poplar before and after densification with the viscoelastic thermal compression (VTC) process were described by pore size distributions and mean pore sizes and compared. The compression of Douglas-fir mainly affected earlywood, while the compression of hybrid poplar mainly occurred in the vessels. In both wood species, the densification resulted in a significant decrease in the pore volumes. The porosity decreased to less than half of the original value for Douglas-fir earlywood and to approximately one-quarter for the vessels in hybrid poplar. The relevant mean pore sizes also decreased dramatically to about one-quarter compared to the original values. In contrast, latewood in Douglas-fir and libriform fibers in hybrid poplar are quite stable under compression. Douglas-fir latewood retained its original structure after compression and did not show any reduction in pore size. The results confirmed that the anatomical structure of VTC densified wood can be described by pore size distributions and mean pore sizes. However, in the case of broad or bimodal distributions, the mean pore sizes are of less significance.

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Acknowledgments

This project was gratefully supported by the ‘FHplus in COIN’ Programme of the Austrian Research Promotion Agency (FFG) under project number 198353.

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Authors and Affiliations

  1. Forest Products Technology and Timber Constructions, Salzburg University of Applied Sciences, Markt 136a, 5431, Kuchl, Salzburg, Austria

    Gernot Standfest & Alexander Petutschnigg

  2. Andrej Marusic Institute, University of Primorska, Muzejski trg 2, 6000, Koper, Slovenia

    Andreja Kutnar

  3. ILTRA d.o.o., Celovska cesta 268, 1000, Ljubljana, Slovenia

    Andreja Kutnar

  4. Research Group Computed Tomography, Upper Austrian University of Applied Sciences, Stelzhamerstraße 23, 4600, Wels, Upper Austria, Austria

    Bernhard Plank

  5. Department of Wood Science and Engineering, Oregon State University, 119 Richardson Hall, Corvallis, OR, 9733, USA

    Frederick A. Kamke

  6. University of Natural Resources and Life Sciences, Peter Jordan Strasse 82, 1190, Vienna, Austria

    Manfred Dunky

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  1. Gernot Standfest
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  2. Andreja Kutnar
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  3. Bernhard Plank
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  4. Alexander Petutschnigg
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  5. Frederick A. Kamke
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  6. Manfred Dunky
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Correspondence to Gernot Standfest.

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Standfest, G., Kutnar, A., Plank, B. et al. Microstructure of viscoelastic thermal compressed (VTC) wood using computed microtomography. Wood Sci Technol 47, 121–139 (2013). https://doi.org/10.1007/s00226-012-0496-5

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  • DOI: https://doi.org/10.1007/s00226-012-0496-5

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