Effect of thermomechanical densification on surface roughness of wood veneers |
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Authors: | Pavlo Bekhta Stanis?aw Proszyk Tomasz Krystofiak Miroslava Mamonova Grzegorz Pinkowski Barbara Lis |
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Institution: | 1. Department of Wood-Based Composites, National University of Forestry and Wood Technology of Ukraine, Lviv, Ukraine;2. Department of Gluing and Finishing of Wood, Poznan University of Life Sciences, Poznan, Poland;3. Department of Wood Science, Technical University in Zvolen, Zvolen, Slovakia;4. Department of Woodworking Machinery and Fundamentals of Machine Construction, Poznan University of Life Sciences, Poznan, Poland |
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Abstract: | The effect of short-term thermomechanical densification of veneer on the surface roughness and surface anatomical changes in four wood species – alder (Alnus glutinosa Gaertn.), beech (Fagus sylvatica L.), birch (Betula verrucosa Ehrh.), and pine (Pinus sylvestris L.) – was studied. Veneer sheets were densified at a temperature of 100, 150, or 200°C and at a pressure of 4, 8, or 12 MPa for 4 minutes. Seven roughness parameters such as Ra, Rz, Rq, Rp, Rv, Rsk, and Rku were determined. Profile surface was recorded using a modified Carl Zeiss ME-10 profile gauging profilometer. Surface anatomical changes of veneer were examined using scanning electron microscopy. The results showed that densification temperature and pressure affect surface roughness of veneer. The surface became smoother, and roughness values decreased significantly (except for Rku which increased slightly) with increasing temperature and pressure of densification. The effect of temperature on surface roughness changes is more pronounced compared with that of densification pressure. The lowest values of surface roughness were recorded for pine veneer samples followed by alder, birch, and beech samples. These results can be used to provide initial data for adhesive application processes in woodworking industry. |
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Keywords: | Surface roughness thermomechanical densification veneer wood species |
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