Iranian Journal of Wood and Paper Industries

Iranian Journal of Wood and Paper Industries

The effect of thermal treatment of Paulownia wood species on the physical and mechanical properties of the resulting layered products

Document Type : Research Paper

Authors
majid bonyaddar 1
Taghi Tabarsa 2
Mehrab Madhoushi 2
Hamid Reza Edalat 2
1 Gorgan University of Agricultural Sciences and Natural Resources
2 Gorgan University
10.22034/ijwp.2025.2044407.1686
Abstract
Problem definition and objectives: layered products is one of the oldest composite wood products, which compared to new engineered products is older. The purpose of this research is to investigate the effect of thermal treatment of Paulownia wood layers on physical and mechanical properties of the resulting layered products.
Methodology: After pealing, the layers were thermally treated by two different procedures, dry and wet, and at two different temperatures for each method. The layers were connected by MDI glue and then the manufactured boards (3 layers and 7 layers) were subjected to water absorption and thickness swelling for 2 and 24 hours, bending properties, internal bonding and shear strength of the glue line.
Results: The results showed that, the modulus of rupture and the modulus of elasticity of the fabricated layered products with treated layers were higher than those made with untreated layers. While the internal bonding was higher in the layered products made with untreated layers. The shear strength of the glue line in the first layers of the layered products was higher in the samples treated by dry method and temperature of 165 °C, than the rest of the samples made in other conditions. The shear strength of the adhesive line in the second and third layers was higher in the control sample than in the samples made with treated layers. The results of water absorption and thickness swelling showed that the amount of these quantities in the samples made with treated layers was significantly less than the layered products made with untreated layers.
Conclusion: The improvement of the physical and mechanical properties of layered products made after thermal treatment of the layers can increase the scope of application of these products in other uses, such as outdoor uses.
Keywords
3 and 7 layered products
thermal treatment
water absorption and thickness swelling
shear strength of the glue line

Subjects

[1] Piri, M., Dahmardeh Ghalehno, M., Farrokhpayam, S.R. and Bahmani, M., 2022. Investigation of ِDecay Resistance of Poplar Plywood with Encapsulated Pesticides. Iranian Journal of Wood and Paper Industries, 13(2), pp.201-212.
[2] Bayatkashkoli, A., Kameshki, B., Ravan, S. and Shamsian, M. (2017). Comparing of performance of treated particleboard with alkaline copper quat, boron-fluorine-chromium-arsenic and Chlorotalonil against Microcerotermes diversus and Anacanthotermes vagans termite. International Biodeterioration & Biodegradation, 120, 186-191. http://dx.doi.org/10.1016/j.ibiod.2017.03.003.
[3] Kashan Dehghan, A., Khademi Eslam, H. and Bazyar, B. (2010). Durability of horn beam (Carpinus betulus) wood in natural state and treated with chromated copper arsenate against Coriolus Versicolor. Iranian Journal of Wood and Paper Science Research, 25(2): 260-274.
[4] Zarey, H.R., Hajihassani, R., Zamani, S.M. and Salehi, K. (2024). Effect of thermo-oil process on biological, physical and mechanical performance of produced thermo wood. Iranian Journal of Wood and Paper Science Research, 39(3): 236-252. DOI: 10.22092/ijwpr.2024.366260.1776.
[5] Kord, B., Taghizadeh Haratbar, D., Malekian, B. and Ismaeilimoghadam, S. (2016). Effect of chemical modification of wood flour on long-term hygroscopic behavior of polypropylene composites. Journal of Thermoplastic Composite Materials, 29(4): 577–588.
[6] Talaei, A., Karimi, A.N., Ebrahimi, G. and Mirshokraee, S.A. (2011). Comparative Study of Heat Treated Beech Wood in Hot Water and Steam Mediums. Iranian Journal of Wood and Paper Industries, 2(1): 27-38.
[7] Ghorbani Kokandeh, M., Akhtari, M. and Movagharnezhad, N. (2012). Influence of Artificial Weathering on Acetylated Beech Solid Wood and Particleboard by Spectroscopy and Electron Microscopy. J. of Wood & Forest Science and Technology, 18(4): 1-14. 
[8] Masoudifar, M. Nosrati, B., Mohebbi Gargari, R. (2018). Effect of surface treatment and titanium dioxide nanoparticles on the mechanical and morphological properties of wood flour/ polypropylene nanocomposites. International Wood Products Journal, 9:4, 176-185, DOI: 10.1080/20426445.2018.1552398.
[9] Viitaniemi P. and Jamsa S. 1996: Modification of wood with heat treatment, Espo 1996, VTT Juskaisuja- Publikationer 814.
[10] Weiland J.J. and Guyonnet R. 1997: Retifiziertes Holz. 16, Verditchter Holzbau in Europa. Motivation, Erfahrung, Entwicklung. Dreilander Holztagung. 10. Joanneum Research Fachtage. 2-5/11/1997. Grazer Congress. Grazz. Austria.
[11] Talaei A. and Yaghoobi K. 2009: Physical and mechanical properties of hydrothermally modified mulberry (Morus alba L.) Wood, The International Research Group on Wood Preservation, IRG Document No. IRG/WP 09-40425.
[12] Sevim Korkut D., Korkut S., Bekar I., Budakçi M., Dilik T. and Çakicier N. 2008: The effects of heat treatment on physical properties and surface roughness of Turkish Hazel (Corylus colurna L.) wood. International Journal of Molecular Sciences (IJMS) 9(9): 1772-1783.
[13] Ghahri, S., Abde, M.R. and Abdoli, F. (2021). Evaluation of applied performance of thermally-modified Fir wood by retification process. Iranian Journal of Wood and Paper Science Research, 36(3): 205-217.
 [14] Hajihassani, R., Mohebby, B., Kazemi Najafi, S. and Navi, P. (2016). Evaluation of physical and mechanical properties of hygro-thermally modified wood. Iranian Journal of Wood and Paper Science Research, 32(1): 1-12.
[15] Song, W., Wei, W., Ren, C. and Zhang, S. (2017). Effect of heat treatment or alkali treatment of veneers on the mechanical properties of Eucalypyus veneer/polyethylene film plywood composites. Bioresources, 12(4): 8683-8703.
[16]. Kartal S.N., Hwang W.J. and Imamura Y. (2008). Combined effect of boron compounds and heat treatment on wood properties: Chemical and strength properties of wood, Journal of Materials Processing Technology 198: 234-240.
[17]. Boonstra M. and Tjeerdsma B. 2006: Chemical analysis of heat treated softwoods, Holz als Rohund werkstoff 64: 204-211.
[18] Bytner, O., Drożdżek, M., Laskowska, A. and Zawadzki, J., (2022). Influence of thermal modification in nitrogen atmosphere on the selected mechanical properties of Black poplar wood (Populus nigra L.). Materials, 15(22): p.7949.
[19] Kozakiewicz, P., Drozdzek, M., Laskowska, A., Grzeskiewicz, M., Bytner, O., Radomski, A. and Zawadzki, J., (2019). Effects of thermal modification on selected physical properties of sapwood and heartwood of black poplar (Populus nigra L.). BioResources, 14(4): 8391-8404.
[20]. Ismaeilimoghadam, S., Nourbakhsh A. and Seyedzadeh Otaghsaraei, S.M. (2016). Calcium silicate formation in calcareous-treated wood flour using nano-silicaand the properties of the wood plastic composite made using the treated wood flour. Iranian Journal of Wood and Paper Science Research, 31(3): 486-499. 
[21] Rautkari, L., and Hill, C. (2014). “Effect of initial moisture content on the anti-swelling efficiency of thermally modified Scots pine sapwood treated in a high-pressure reactor under saturated steam,” Holzforschung 68(3), 323-326. DOI:10.1515/hf-2013- 0078.
[22]. Repellin, V. and Guyonnet, R. (2005). Evaluation of heat-treated wood swelling by differential scanning calorimetry in relation to chemical composition. Holzforschung, 59(1), 28–34pp.
 
[23] - Bekhta, P. (2020). Effect of heat treatment on some physical and mechanical properties of birch plywood. European Journal of Wood and Wood Products, https://doi.org/10.1007/s00107-020-01560-7.
[24] Ismaeilimoghadam, S., Masoudifar, M., Shamsian, M., Nosrati Sheshka, B. and Seyeedzadeh Otaghsarae, S.M. (2016). The effect of chemical treatment of wood flour on some properties of wood-plastic composites. Iranian Journal of Wood and Paper Industries, 7(3): 449-462.
Iranian Journal of Wood and Paper Industries
Volume 16, Issue 1
Winter 2025
Pages 63-72