Comparison of thermal modification method with air and oil on physical and mechanical properties of Paulownia wood

Document Type : Complete scientific research article

Authors

1 Assistant professor of Department of Paper Science and Engineering, Faculty of Wood and Paper Engineering

2 Assistant Prof, Department of Wood Engineering and Technology, Faculty of Wood and Paper Engineering, Gorgan University of Agricultural Sciences and Natural Resources

Abstract

Background and objective: One of the ways to supply wood raw material is to plant fast-growing species, with regards to the lack of forest resources and the increase in demand for wood and its products. One of the fast-growing species cultivated in our country is Paulownia fortune, which has unique characteristics. Nowadays these valuable materials are modified in various ways, due to the importance of optimal use of wood in various applications.. Thermal modification, as an efficient and environmentally friendly method, is a suitable option for improving the characteristics of fast-growing wood species. Therefore, in this study, the effect of thermal treatment in air and oil on some physical and mechanical properties of Paulownia fortunei wood was investigated.
Materials and methods: The wood used in this research was three trunks of Paulownia tree (Paulownia fortune) from Shasat Kalate forest of Gorgan University of Agricultural Sciences and Natural Resources. The wood was dried in the open air after turning into boards. Then wooden samples with straight fibers and flawless appearance were prepared from them. The samples were modified by two thermal modification methods in air and oil. Thermal modification in air was done according to Thermo-D process (at 212 ± 3 ◦C and 2 hours). Also, thermal modification with rapeseed oil was used for the treatment of samples with the same temperature conditions as the method of thermal modification in air. Then colorimetric test, bending strength, hardness, impact resistance, water absorption and thickness shrinkage tests were performed on the samples.
Findings: Results revealed that heat treatment with both methods had a significant effect on density, volumetric shrinkage and water absorption, colorimetry, impact resistance, hardness resistance, modulus of rupture and modulus of elasticity. In general, heat treatment with both methods caused a decrease in density, water absorption and elongation, brightness index, impact resistance, hardness, modulus of rupture and modulus of elasticity. The density, water absorption and volumetric shrinkage of the samples treated in oil were higher compared to the samples treated in air. The impact resistance, hardness resistance, modulus of rupture and modulus of elasticity of the samples treated in oil were significantly higher compared to the samples treated in air.
Conclusion: In general, Paulownia fortune treated in oil showed relatively better physical and mechanical properties compared to the one treated in air. Therefore, heat treatment in oil is a more effective method to improve the physical and mechanical properties of Paulownia fortune wood compared to heat treatment in air.

Keywords

Main Subjects


1.Import and export statistics of all types of raw wood, compressed wood, furniture, pulp and paper in 1401. (1402). Iranian Wood Industry Employers' Association. Number 14125. https:// www.iranwoodind.com/ main_fa.asp? status= statistics [In Persian]
2.Esteves, B., Ferreira. H., Viana, H., Ferreira, J., Domingos, I., Cruz-Lopes, L., Dennis, J., & Lina, N. (2021). Termite resistance, chemical and mechanical characterization of Paulownia tomentosa wood before and after heat treatment. Forests. 12 (8), 1114.
3.Rasouli, D., Bahmani, M., & Humar, M. (2017). Impregnability of Paulownia and Populus wood with copper based preservatives. Drvna industrija, 68 (3), 211-218.
4.Hill, C. A. S. (2006). Wood modification: chemical, thermal and other processes. John Wiley & Sons, Chichester. UK.
5.Karbalaei, H., Tarmian, A., Rasouli, D., & Pourmahdian, S. (2022). Effects of UV-curing epoxy acrylate and urethane acrylate coatings incorporated with ZnO nanoparticles on weathering resistance of thermally modified timber. Wood Material Science & Engineering, 17 (6), 868-877.
6.Rep, G., & Pohleven, F. (2001). Wood modification-a promising method for wood preservation. Drvna industrija.
52 (2), 71-76.
7.Yildiz, S., Yildiz, U., Colakolu, G., Derya, E., & Temyz Ali, G. (2003). The effects of heat treatment on the specific gravity of Beech and Spruce wood. IRG 34th Annual.
8.Kocaefe, D., Chaudry, B., Ponscak, S., Bouazara, M., & Pichette, A. (2007). Thermogravimetric study of high temperature treatment of Aspen: effect of treatment parameters on weight loss and mechanical properties. J. of Material Sciences. 42 (3), 854-866.
9.Despot, R., Hasan, M., Jug, M., & Sefc, B. (2008). Biological durability of wood modified by citric acid. DRVNA INDUSTRIJA. 59 (2), 55-59.
10.Militz, H., & Altgen, M. (2014) Processes and properties of thermally modified wood manufactured in Europe. In T. P. Schultz, B. Goodell and
D. D. Nicholas (eds.) Deterioration and Protection of Sustainable Biomaterials. ACS Symposium Series 1158 (Oxford University Press), Pp. 269-285.
11.Dubey, M. K., Pang, S., & Walker, J. (2012). Changes in chemistry, color, dimensional stability and fungal resistance of Pinus radiata D. Don Wood with Oil Heat-Treatment Holzforschung. 66 (1), 49-57.
12.Surini, T., Charrier, F., Malvestio, J., Charrier, B., Moubarik, A., Castera, P., & Grelier, S. (2012). Physical properties and termite durability of maritime pine Pinus pinaster Ait., heat-treated under vacuum pressure. Wood Science Technology. 46 (1), 487-501.
13.Suri, I. F., Purusatama, B. D., Kim, J. H., Yang, G. U., Prasetia, D., Kwon, G. J., Hidayat, W., Lee, S. H., Febrianto, F., & Kim, N. H. (2022). Comparison of physical and mechanical properties of Paulownia tomentosa and Pinus koraiensis wood heat treated in oil and air. European J. of Wood and Wood Products. 80, 1389-1399.
14.Hidayat, W., Jang, J. H., Park, S. H., Qi, Y., Febrianto, F., Lee, S. H., & Kim, N. H. (2015). Effect of temperature and clamping during heat treatment on physical and mechanical properties of Okan (Cylicodiscus gabunensis [Taub.] Harms) wood. BioResources. 10 (4), 6961-6974.
15.Herrera-Diaz, R., Sepulveda-Villaroel, V., Torres-Mella, J., Salvo-Sepulveda, L., Llano-Ponte, R., Salinas-Lira, C., Peredo, M. A., & Ananias, R. A. (2019). Infuence of the wood quality and treatment temperature on the physical and mechanical properties of thermally modifed radiata pine. European J. of Wood and Wood Products. 77 (4), 661-671.
16.Kol, H. S. (2010). Characteristics of heat-treated Turkish pine and fir wood after ThermoWood processing. J. of Environmental Biology. 31: 6. 1007-1011.
17.Ayrilmis, N., Jarusombuti, S., Fueangvivat, V., & Bauchongkol, P. (2011). Effect of thermal-treatment of wood fibres on properties of flat-pressed wood plastic composites. Polymer Degradation and Stability. 96 (5), 818-822.
18.Dubey, M. K., Pang, S., & Walker, J. (2011). Efect of oil heating age on color and dimensional stability of heat treated Pinus radiata. European J. of Wood and Wood Products. 69 (2), 255-265.
19.Umar, I., Zaidon, A., Lee, S.H., & Halis, R. (2016). Oil-heat treatment of rubberwood for optimum changes in chemical constituents and decay resistance. J. of Topical Forest Science. 28 (1), 88-96.
20.Rapp, A. O., & Sailer, M. (2001). Oil heat treatment of wood in Germany- state of the art. Holz Roh Werkstoff. Germany. Hamburg.
21.Okon, K. E., Lin, F., Lin, X., Chen, C., Chen, Y., & Huang, B. (2018). Modifcation of Chinese fr (Cunninghamia lanceolata L.) wood by silicone oil heat treatment with micro-wave pretreatment. European J. of Wood and Wood Products. 76, 221-228.
22.Cheng, D., Chen, L., Jiang, S., & Zhang, Q. (2014). Oil uptake percentage in oil-heat-treated wood, its determination by soxhlet extraction, and its effects on wood compression strength parallel to grain. BioResources. 9 (1), 120-131.
23.Torniainen, P., Popescu, C. M., Jones, D., Scharf, A., & Sandberg, D. (2021). Correlation of Studies between Colour, Structure and Mechanical Properties of Commercially Produced ThermoWood® Treated Norway Spruce and Scots Pine. Forests. 12, 1165. https://doi.org/ 10. 3390/f12091165.
24.Xue-Hua, W., Ben-hua, F., & Jun-liang, L. (2014). Effect of vacuum heat treatment temperature on physical and mechanical properties of Eucalyptus pellita wood. Wood and Fiber Science. 2014, 368-3675.
25.Guller, B. (2012). Effects of heat treatment on density, dimensional stability and color of Pinus nigra wood. African J. of biotechnology. 11 (9), 2204-2209.
26.Mohebby, B., Kevily, H., & Kazemi-Najafi, S. (2014). Oleothermal modification of fir wood with a combination of soybean oil and maleic anhydride and its effects on physico-mechanical properties of treated wood. Wood Science and Technology. 48, 797-809.
27.Frederique Bidzanga Bessala, L., Gao, J., He, Z., Wang, Z., & Yi, S. (2023). Effects of Heat Treatment on Color, Dimensional Stability, Hygroscopicity and Chemical Structure of Afrormosia and Newtonia Wood: A Comparative Study of Air and Palm Oil Medium. Polymers. 15, 774. https://doi.org/ 10.3390/polym15030774.
28.Korkut, D. S., Korkut, S., Bekar, I., Budakçi, M., Dilik, T., & Çakicier, N. (2008). The effects of heat treatment on the physical properties and surface roughness of Turkish hazel (Corylus colurna L.) wood. International J. of Molecular Sciences. 9 (9), 1772-1783.
29.Korkut, S., Akgül, M., & Dündar, T. (2008). The effects of heat treatment on some technological properties of
Scots pine (Pinus sylvestris L.) wood. Bioresource Technology. 99 (6), 1861-1868.
30.Sundqvist, B., & Morén, T. (2002). The influence of wood polymers and extractives on wood colour induced by hydrothermal treatment. European J. of Wood and Wood Products. 60 (5), 375-6.
31.Sundqvist, B. (2004). Colour changes and acid formation in wood during heating: Luleå tekniska universitet;
32.Tjeerdsma, B., Boonstra, M., Pizzi, A., Tekely, P., & Militz, H. (1998). Characterisation of thermally modified wood: molecular reasons for wood performance improvement. Holz als Roh-und Werkstoff. 56 (3), 149-153.
33.Bekhta, P., & Niemz, P. (2003). Effect of high temperature on the change in color, dimensional stability and mechanical properties of spruce wood. Holzforschung. 57 (5), 539-546.
34.Vidholdová, Z., Slabejová, G., & Šmidriaková, M. (2021). Quality of oiland wax-based surface finishes on thermally modified oak wood. Coatings. 11 (2), 143.
35.Bakar, B. F. A., Hiziroglu, S., & Tahir, P. M. (2013). Properties of some thermally modified wood species. Materials & Design. 43, 348-355.
36.Navi, P., & Sandberg, D. (2012). Thermo- hydro- mechanical wood processing: Crc Press. 357p.
37.Rapp, A.O., & Sailer, M. (2001). Oil heat treatment of wood in Germany- state of the art. Holz Roh Werkstoff. Germany. Hamburg.
38.Mohebby, B., Sharifnia-Dizboni, & H., Kazemi-Najafi, S. (2009). Combined hydro-thermo-mechanical modification (CHTM) as an innovation in mechanical wood modification. Proceeding of 4th European Conference on Wood Modification (ECWM4), Stockholm, Sweden.