EVALUATION OF BONDING CHARACTERISTICS OF GREY POPLAR (POPULUS X CANESCENS)
Keywords:
Grey poplar; shear strength; PVAc; PUR structural adhesive, CLT panel.Abstract
Coniferous forests are drying out due to climate change, creating a need for alternative species. Grey poplars (Populus × canescens) are underutilized in Hungary, with about 12 million m³ reaching harvesting age by the end of 2026 and decaying due to limited industrial use. The bondability of grey poplar with structural polyurethane (PUR) and nonstructural polyvinyl acetate (PVAc) adhesives, comparing it with Scots pine (Pinus sylvestris) and beech (Fagus sylvatica) under both dry and wet conditions, in accordance with EN standards is evaluated in the study. Beech met the minimum dry tensile shear strength requirements for both adhesives, whereas grey poplar and Scots pine did not. Grey poplar bonded with PVAc showed higher dry strength than Scots pine, while Scots pine with PUR outperformed grey poplar. Despite its higher density, grey poplar heartwood exhibited lower strength than sapwood. Overall, grey poplar’s adhesive performance was comparable to Scots pine, suggesting it could serve as a viable alternative to coniferous species in both load-bearing and non-load-bearing applications.
References
Aiton, W., 1789. Hortus Kewensis. Vol. 3. George Nicol, London, Great Britain, 405 pp.
Borovics, A., Király, É., Kottek, P., 2025. Climate change mitigation strategies at the level of a forestry company in the light of age class legacy effects. Annals of Forest Science, 82, 10, 1–17. https://doi.org/10.1186/s13595-025-01282-x
Büyüksarı, Ü., As, N., Dündar, T., 2017. Mechanical properties of earlywood and latewood sections of Scots pine wood. BioResources, 12, 4004–4012. https://doi.org/10.15376/biores.12.2.4004-4012
Doruk, Ş., 2021. Determining the effect of synthetic based varnish and impregnation on wood’s shear strength under cold climate conditions. BioResources, 16(2), 3377–3390. https://doi.org/10.15376/biores.16.2.3377-3390
EN 205:2016. Adhesives — Wood adhesives for non-structural applications — Determination of tensile shear strength of lap joints.
EN 302-1:2023. Adhesives for load bearing timber structures — Test methods — Part 1: Determination of longitudinal tensile shear strength.
EU Carbon Removal Certification Framework, 2025. Available online: https://climate.ec.europa.eu/eu-action/carbon-removals-and-carbon-farming_en (accessed 30 July 2025)
Follrich, J., Teischinger, A., Gindl, W., Müller, U., 2008. Adhesive bond strength of end grain joints in softwood with varying density. Holzforschung, 62(2), 1–12. https://doi.org/10.1515/HF.2008
Hass, P., Wittel, F.K., Mendoza, M., Niemz, P., Herrmann, H.J., 2012. Adhesive penetration in beech wood: experiments. Wood Science and Technology, 46, 243–256. https://doi.org/10.1007/s00226-011-0410-6
Ilgın, H.E., Karjalainen, M., Mikkola, P., 2023. Views of Cross Laminated Timber (CLT) manufacturer representatives around the world on CLT practices and its future outlook. Buildings, 13, 2912. https://doi.org/10.3390/buildings13122912
Kánnár, A., Csiha, C., 2021. Comparative analysis of static and dynamic MOE of Pannónia poplar timber from different plantations. Wood Research, 66, 195–202. https://doi.org/10.37763/wr.1336-4561/66.2.195-202
Kärki, T., 2001. Variation of wood density and shrinkage in European aspen (Populus tremula). Holz als Roh- und Werkstoff, 59, 79–84. https://doi.org/10.1007/s001070050479
Király, É., Forsell, N., Schulte, M., Kis Kovács, G., Börcsök, Z., Kocsis, Z., Kottek, P., Mertl, T., Németh, G., Polgár, A., Borovics, A., 2024. Climate change mitigation potentials of wood industry related measures in Hungary. Mitigation and Adaptation Strategies for Global Change, 29, 62, 1–24. https://doi.org/10.1007/s11027-024-10161-1
Konnerth, J., Kluge, M., Schweizer, G., Miljković, M., Gindl Altmutter, W., 2016. Survey of selected adhesive bonding properties of nine European softwood and hardwood species. European Journal of Wood and Wood Products, 74, 809–819. https://doi.org/10.1007/s00107-016-1087-1
Li, R., Guo, X., Ekevad, M., Marklund, B., Cao, P., 2015. Investigation of glueline shear strength of pine wood bonded with PVAc by response surface methodology. BioResources, 10, 3831–3838. https://doi.org/10.15376/biores.10.3.3831-3838
Meethaworn, B., Srivaro, S., Khongtong, S., 2022. High performance adhesive joint made from densified wood. Polymers, 14(3), 515. https://doi.org/10.3390/polym14030515
Molnár, S., Bariska, M., 2002. Wood species of Hungary. 1st ed. Szaktudás Kiadó Ház Zrt, Budapest, Hungary, 143 pp. https://doi.org/10.1007/s40725-018-0071-x
Parresol, B.R., Cao, F., 1998. An investigation of crystalline intensity of the wood of poplar clones grown in Jiangsu Province, China. Research Paper SRS 11, U.S. Department of Agriculture, Forest Service, Southern Research Station, Asheville, NC, 1–7 pp.
Populus × canescens, 2025. Available online: https://en.wikipedia.org/wiki/Populus_%C3%97_canescens (accessed 30 July 2025).
Shen, H., Xing, X., Guan, Y., Zhou, L., Liu, S., Gao, H., 2021. Radial variation studies on wood properties of Populus deltoides parents and their hybrids. BioResources, 16(3), 4905–4923. https://doi.org/10.15376/biores.16.3.4905-4923
Smith, J.E., 1804. Flora Britannica. Vol. 3. London, Great Britain, 1080 pp. Available online: https://archive.org/details/b22038735_0003/page/1080/mode/2up (accessed 30 July 2025).
Types of Poplar wood, uses, advantages, and disadvantages, 2025. Available online: https://www.timberblogger.com/poplar-wood (accessed 30 July 2025).
Wagenführ, R., Niemz, P., Schmidt, M., Schweizer, G., Kluge, M., Miljković, M., Gindl Altmutter, W., 2016. Survey of selected adhesive bonding properties of nine European softwood and hardwood species. European Journal of Wood and Wood Products, 74(6), 809–819. https://doi.org/10.1007/s00107-016-1087-1
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