EFFECT OF HEAT TREATMENT ON THE BONDING QUALITY OF WOOD VENEERS TO PLYWOOD PRODUCTION
DOI:
https://doi.org/10.5902/1980509831585Keywords:
temperature, wettability, Pinus taeda, shear strenght in the bondline.Abstract
Plywood is a wood panel that can be used both in the furniture industry and in construction due to its structural use. However, to be used in construction, it needs to be resistant against wood decay agents and water, without compromising its mechanical properties. The heat treatment is an alternative treatment which improves the wood resistance to fungi and improves its dimensional stability. Thus, the objective of this study is to evaluate the influence of the heat treatment with three different temperatures, 160, 180 and 200°C in the wettability of wood veneers and the shear strength in the bond line of the plywood produced with them. To do so, it was carried out the wettability testing using digital goniometer in the treated veneers at three temperatures and for the control specimen. Besides, it was carried out the shear strength in the bond line test, for testing the quality of bonding according to ABNT NBR ISO 12466-1 (2006). Because of the results obtained, it could be seen that the surface of the treated wood became more hydrophobic with increasing temperature, and this also resulted in a decrease in shear strength in the bond line, once the adhesive used (phenol-formaldehyde) is water based, however, the regulatory requirements have been met.
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References
ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS. NBR ISO 12466-1: Compensado: determinação da massa específica aparente. Rio de Janeiro, 2006.
ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS. NBR ISO 12466-2: Compensado: determinação da massa específica aparente. Rio de Janeiro, 2006.
BOONSTRA, M. J. et al. Optimisation of a two-stage heat treatment process: durability aspects. Wood Science and Technology, München, v. 41, n. 1, p. 31-57, 2007.
BROSSE, N. et al. Investigation of the chemical modifications of beech wood lignin during heat treatment. Polymer Degradation and Stability, Aubière, v. 95, n. 9, p. 1721-1726, 2010.
GÉRARDIN, P. et al. Evolution of wood surface free energy after heat treatment. Polymer Degradation and Stability, Aubière, v. 92, n. 4, p. 653-657, 2007.
GONZÁLEZ-PEÑA, M. M.; CURLING, S. F.; HALE, M. D. C. On the effect of heat on the chemical composition and dimensions of thermally-modified wood. Polymer Degradation and Stability, Aubière, v. 94, n. 12, p. 2184-2193, 2009.
GUNDUZ, G.; AYDEMIR, D.; KARAKAS, G. The effects of thermal treatment on the mechanical properties of wild Pear (Pyrus elaeagnifolia Pall.) wood and changes in physical properties. Materials and Design, Oxford, v. 30, n. 10, p. 4391-4395, 2009.
GÜNDÜZ, G.; KORKUT, S.; KORKUT, D. S. The effects of heat treatment on physical and technological properties and surface roughness of Camiyani Black Pine (Pinus nigra Arn. subsp. pallasiana var. pallasiana) wood. Bioresource technology, Mohali, v. 99, n. 7, p. 2275-2280, 2008.
HAKKOU, M. et al. Investigation of wood wettability changes during heat treatment on the basis of chemical analysis. Polymer Degradation and Stability, Aubière, v. 89, n. 1, p. 1-5, 2005.
HAKKOU, M. et al. Investigations of the reasons for fungal durability of heat-treated beech wood. Polymer Degradation and Stability, Aubière, v. 91, n. 2, p. 393-397, 2006.
IWAKIRI, S. Painéis de madeira reconstituída. Curtiba: FUPEF, 2005. 247 p.
KAČÍKOVÁ, D. et al. Effects of thermal treatment on chemical, mechanical and colour traits in Norway spruce wood. Bioresource Technology, Mohali, v. 144, p. 669-674, 2013.
KAMDEM, D. P.; PIZZI, A.; JERMANNAUD, A. Durability of heat-treated wood. Holz als Roh - und Werkstoff, München, v. 60, n. 1, p. 1-6, 2002.
KORKUT, S.; AKGÜL, M.; DÜNDAR, T. The effects of heat treatment on some technological properties of Scots pine (Pinus sylvestris L.) wood. Bioresource Technology, Mohali, v. 99, n. 6, p. 1861-1868, 2008.
KORKUT, S. et al. The effects of heat treatment on technological properties in Red-bud maple (Acer trautvetteri Medw.) wood. Bioresource Technology, Mohali, v. 99, n. 6, p. 1538–1543, 2008.
NAVI, P.; SANDBERG, D. Heat Treatment. In: NAVI, P.; SANDBERG, D. Thermo-Hydro-Mechanical processing of wood. Boca Raton: CRC Press, 2012. cap. 9.
MENDES R. F. Efeito do tratamento térmico sobre painéis OSB. 2010. 116 f. Dissertação (Mestrado em Recursos Florestais) – Universidade de São Paulo, Piracicaba, 2010.
PONCSAK, S.; KOCAEFE, D.; YOUNSI, R. Improvement of the heat treatment of Jack pine (Pinus banksiana) using ThermoWood technology. European Journal of Wood and Wood Products, München, v. 69, n. 2, p. 281-286, 2011.
SALCA, E. A.; HIZIROGLU, S. Evaluation of hardness and surface quality of different wood species as function of heat treatment. Materials and Design, Oxford, v. 62, p. 416-423, 2014.
SILVA, D. A. Avaliação da eficiência energética em uma indústria de painéis compensado. 2001. 205 f. Tese (Doutorado em Ciências Florestais) – Universidade Federal do Paraná, Curitiba, 2001.
SILVA, M. R. Efeito do tratamento térmico nas propriedades químicas, físicas e mecânicas em elementos estruturais de Eucalipto citriodora e Pinus taeda. 2012. 223 f. Tese (Doutorado em Ciência e Engenharia dos Materiais) – Universidade de São Paulo, São Carlos, 2012.
SOARES, A. C. et al. Molhabilidade em amostras de Araucaria angustifolia e Pinus elliottii após tratamento térmico e envelhecimento. Scientia Forestalis, Piracicaba, v. 39, n. 92, p. 447-456, 2011.
TJEERDSMA, B. F. et al. Characterisation of thermally modified wood: molecular reasons for wood performance improvement. Holz als Roh- und Werkstoff, München, v. 56, p. 149-153, 1998.
UNSAL, O.; AYRILMIS, N. Variations in compression strength and surface roughness of heat-treated Turkish river red gum (Eucalyptus camaldulensis) wood. Journal of Wood Science, Uji, v. 51, n. 4, p. 405-409, 2005.
WEILAND, J. J.; GUYONNET, R. Study of chemical modifications and fungi degradation of thermally modified wood using DRIFT spectroscopy. Holz als Roh- und Werkstoff, München, v. 61, p. 216-220, 2003.
WINDEISEN, E.; STROBEL, C.; WEGENER, G. Chemical changes during the production of thermo-treated beech wood. Wood Science and Technology, München, v. 41, n. 6, p. 523-536, 2007.
YILDIZ, S.; GEZER, E. D.; YILDIZ, U. C. Mechanical and chemical behavior of spruce wood modified by heat. Building and Environment, West Lafayette, v. 41, n. 12, p. 1762-1766, 2006.
