Effect of microwave treatment on drying and water impregnability of Pinus pinaster and Eucalyptus globulus


  • Fernando Júnior Resende Mascarenhas
  • Alfredo Manuel Pereira Geraldes Dias
  • André Luis Christoforo
  • Rogério Manuel dos Santos Simões
  • André Eduardo Palos Cunha




Compression strength, microwave treatment, Portuguese wood species, small clear specimens, water uptake


Wood is a material that has been used by humankind for a long time. However, wood researchers and industry have always been concerned about the issues during wood drying and the permeability problems of certain species. In this sense, microwave technology has been applied for wood drying and improving permeably. This paper investigates the microwave drying of two Portuguese wood species, Pinus pinaster sap and heartwood and Eucalyptus globulus heartwood using small clear specimens. The samples were grouped into six during each microwave treatment run according to their similarity of initial moisture content. Once the drying was completed, control and microwave -treated samples were impregnated with desalinated water to analyze their improvement in water absorption, and the compression strength parallel to the grain was analyzed. The results showed that each wood species behaves differently under microwave drying and initial moisture content. The impregnation results demonstrated that pine and eucalyptus microwave -treated heartwood samples improved their capability to absorb water. Finally, only the microwave -treated specimens of eucalyptus heartwood presented a decrease in the values of compression strength parallel to the grain compared to the control group. Therefore, MW treatment presents possibilities for further applications for the wood industry with supporting results.


Download data is not yet available.


Aksenov, A.A.; Malyukov, S.V. 2020. Microwave modification of wood: Determination of mechanical properties of softwood. IOP Conf Ser: Earth Environ Sci 595(1): 1-8. https://doi.org/10.1088/1755-1315/595/1/012012

Antti, A.L. 1995. Microwave drying of pine and spruce. Holz Roh Werkst 53(5): 333–338. https://doi.org/10.1007/s001070050102

Balboni, B.M.; Ozarska, B.; Garcia, J.N.; Torgovnikov, G. 2018. Microwave treatment of Eucalyptus macrorhyncha timber for reducing drying defects and its impact on physical and mechanical wood properties. Eur J Wood Prod 76(3): 861–870. https://doi.org/10.1007/s00107-017-1260-1

Chuchala, D.; Sandak, J.; Orlowski, K.A.; Muzinski, T.; Lackowski, M.; Ochrymiuk, T. 2020. Effect of the drying method of pine and beech wood on fracture toughness and shear yield stress. Materials 13(20): 1–17. https://doi.org/10.3390/ma13204692

Comstock, G.L.; Côté, W.A. 1968. Factors affecting permeability and pit aspiration in coniferous sapwood. Wood Sci Technol 2(4): 279–291. https://doi.org/10.1007/BF00350274

Esteves, B.; Marques, A.V.; Domingos, I.; Pereira, H. 2007. Influence of steam heating on the properties of pine (Pinus pinaster) and eucalypt (Eucalyptus globulus) wood. Wood Sci Technol 41(3): 193–207. https://doi.org/10.1007/s00226-006-0099-0

European Committee for Standardization. 2004. Eurocode 5: Design of Timber Structures - Part 1-1: General - Common Rules and Rules for Buildings Eurocode. CEN EN 1995-1-1. CEN, Brussels, Belgium. https://eurocodes.jrc.ec.europa.eu/showpage.php?id=135

European Committee for Standardization. 2012. Timber Structures - Structural Timber and Glued Laminated Timber - Determination of Some Physical and Mechanical Properties. EN 408: CEN, Brussels, Belgium. https://www.en-standard.eu/bs-en-408-2010-a1-2012-timber-structures-structural-timber-and-glued-laminated-timber-determination-of-some-physical-and-mechanical-properties/

Ganguly, S.; Balzano, A.; Petriˇ, M.; Kržišnik, D.; Tripathi, S. 2021. Effects of Different Energy Intensities of Microwave Treatment on Heartwood and Sapwood Microstructures in Norway Spruce. Forests 12: 1–16. https://doi.org/10.3390/f12050598

Hansson, L.; Antti, A.L. 2003. The effect of microwave drying on Norway spruce woods strength: A comparison with conventional drying. J Mater Process Technol 141(1): 41–50. https://doi.org/10.1016/S0924-0136(02)01102-0

Haque, M.N. 2007. Analysis of heat and mass transfer during high temperature drying if Pinus radiata. Drying Technol 25(2): 379–389. https://doi.org/10.1080/07373930601184551

Harris, G.A.; Torgovnikov, G.; Vinden, P.; Brodie, G.I.; Shaginov, A. 2008. Microwave pretreatment of backsawn messmate boards to improve drying quality: Part 1. Drying Technol 26(5): 579–584. https://doi.org/10.1080/07373930801944770

Hermoso, E.; Vega, A. 2016. Effect of microwave treatment on the impregnability and mechanical properties of Eucalyptus globulus wood. Maderas-Cienc Tecnol 18(1): 55–64. https://doi.org/10.4067/S0718-221X2016005000006

Herrera-Díaz, R.; Sepúlveda-Villarroel, V.; Pérez-Peña, N.; Salvo-Sepúlveda, L.; Salinas-Lira, C.; Llano-Ponte, R.; Ananías, R.A. 2018. Effect of wood drying and heat modification on some physical and mechanical properties of radiata pine. Drying Technol 36(5): 537–544. https://doi.org/10.1080/07373937.2017.1342094

ICNF. 2019. Inventário Florestal Nacional (IFN6) – Principais resultados – relatório sumário. 34 pp, Instituto da Conservação da Natureza e das Florestas. Lisboa. https://www.fc.up.pt/pessoas/mccunha/Silvicultura/Aulas/estatisticas/IFN6-Principais-resultados-Jun2019.pdf

Jirouš-Rajković, V.; Miklečić, J. 2021. Enhancing Weathering Resistance of Wood—A Review. Polymers 13(12): 1-27. https://doi.org/10.3390/polym13121980

Kol, H.Ş.; Çayır, B. 2021. Increasing the Impregnability of Oriental Spruce Wood via Microwave Pretreatment. BioResources 16(2): 2513–2523. https://doi.org/10.15376/biores.16.2.2513-2523

Kol, H.Ş.; Çayır, B. 2022. The effects of increasing preservative uptake by microwave pre-treatment on the microstructure and mechanical properties of Oriental spruce wood. Wood Mater Sci Eng 1–7. https://doi.org/10.1080/17480272.2022.2077656

Kumar, P.P.; Kumar, S.H.; Sihag, K.; Tripathi, S. 2016. Effect of microwave treatment on longitudinal air permeability and preservative uptake characteristics of chir pine wood. Maderas-Cienc Tecnol 18(1): 125–132. https://doi.org/10.4067/S0718-221X2016005000013

Leggate, W.; Kumar, C.; MGavin, R.L.; Faircloth, A.; Knackstedt, M. 2021. The Effects of Drying Method on the Wood Permeability, Wettability, Treatability, and Gluability of Southern Pine from Australia. BioResources 16(1): 698–720. https://doi.org/10.15376/biores.16.1.698-720

Lepage, E.S. 1986. Manual de preservação de madeiras (In Portuguese). IPT, São Paulo, Brazil.

Longue Júnior, D.; Colodette, J.L. 2013. Importância e versatilidade da madeira de eucalipto para a indústria de base florestal. Pesquisa Florestal Brasileira 33(76): 429–438. https://doi.org/10.4336/2013.pfb.33.76.528

Majano-Majano, A.; Lara-Bocanegra, A.J.; Xavier, J.; Morais, J. 2020. Experimental evaluation of mode II fracture properties of Eucalyptus globulus L. Materials 13(3): 1–13. https://doi.org/10.3390/ma13030745

Mascarenhas, F.J.R.; Dias, A.M.P.G.; Christoforo, A.L. 2021. State of the Art of Microwave Treatment of Wood: Literature Review. Forests 12(745): 1–31. https://doi.org/10.3390/f12060745

Melo, J.E.; Souza, M.R.; Costa, A.F. 2015. Influência das dimensões dos corpos de prova e da velocidade de ensaio na resistência à flexão estática de três espécies de madeiras tropicais. Cienc Florest 25(2): 415–424. https://doi.org/10.5902/1980509818461

Minitab. LLC. 2017. Minitab Version 18. https://www.minitab.com/en-us/

Morgado, T.F.M.; Dias, A.M.P.G.; Machado, J.S.; Negrão, J.H. 2013. Structural Connections for Small-Diameter Poles. J Struct Eng 139(11): 2003–2009. https://doi.org/10.1061/(asce)st.1943-541x.0000752

Morgado, T.F.M.; Dias, A.M.P.G.; Machado, J.S.; Negrão, J.H.; Marques, A.F.S. 2017. Grading of Portuguese Maritime Pine Small-Diameter Roundwood. J Mater Civ Eng 29(2). https://doi.org/10.1061/(asce)mt.1943-5533.0001721

Ndukwu, M.C.; Bennamoun, L.; Simo-Tagne, M.; Ibeh, M.I.; Abada, U.C.; Ekop, I.E. 2021. Influence of drying applications on wood, brick and concrete used as building materials: a review. J Build Rehabil 6(1): 1–19. https://doi.org/10.1007/s41024-021-00119-0

Nunes, L.J.R.; Meireles, C.I.R.; Gomes, C.J.P.; Ribeiro, N.M.C. de A. 2019. Socioeconomic aspects of the forests in Portugal: Recent evolution and perspectives of sustainability of the resource. Forests 10(5): 1–11. https://doi.org/10.3390/f10050361

Oloyede, A.; Groombridge, P. 2000. The Influence of microwave heating on the mechanical properties of wood. J Mater Process Technol 100(1): 67–73. https://doi.org/10.1016/S0924-0136(99)00454-9

Ouertani, S.; Koubaa, A.; Azzouz, S.; Bahar, R.; Hassini, L.; Belghith, A. 2018. Microwave drying kinetics of jack pine wood: determination of phytosanitary efficacy, energy consumption, and mechanical properties. Eur J Wood Prod 76(4): 1101–1111. https://doi.org/10.1007/s00107-018-1316-x

Penvern, H.; Zhou, M.; Maillet, B.; Courtier-Murias, D.; Scheel, M.; Perrin, J.; Weitkamp, T.; Bardet, S.; Caré, S.; Coussot, P. 2020. How Bound Water Regulates Wood Drying. Phys Rev Appl 14(5): 1-20. https://doi.org/10.1103/PhysRevApplied.14.054051

Poonia, P.K.; Tripathi, S. 2018. Effect of microwave heating on pH and termite resistance of Pinus roxburghii Wood. Maderas-Cienc Tecnol 20(3): 499–504. https://doi.org/10.4067/S0718-221X2018005031901

Poonia, P.K.; Deepa, S.R.; Kumar, M.; Kumar, A. 2021. Viability of Wood Decaying Fungal Mycelium after Microwave Radiation of Bamboo Culm. Maderas-Cienc Tecnol 23(4): 1–6. https://doi.org/10.4067/s0718-221x2021000100404

Ramezanpour, M.; Tarmian, A.; Taghiyari, H.R. 2014. Improving impregnation properties of fir wood to acid copper chromate (ACC) with microwave pre-treatment. IForest 8: 89–94. https://doi.org/10.3832/ifor1119-007

Rego, F.; Louro, G.; Constantino, L. 2013. The impact of changing wildfire regimes on wood availability from Portuguese forests. Forest Policy and Economics 29: 56–61. https://doi.org/10.1016/j.forpol.2012.11.010

Ross, R.J. 2010. Wood Handbook - Wood as an Engineering Material. Centennial ed. General technical report FPL, Madison, United States of America. https://doi.org/10.1161/01.RES.39.4.523

Samani, A.; Ganguly, S.; Kanyal, R.; Tripathi, S. 2019. Effect of microwave pre-treatment on preservative retention and treatability of Melia composita wood. J For Sci 65(10): 391–396. https://doi.org/10.17221/39/2019-JFS

Santos, J.A. 2015. A riqueza das madeiras portuguesas. Propriedades e Fichas Técnicas (In Portuguese). AIMMP – Associação das Indústrias de Madeira e Mobiliário de Portugal, Porto, Portugal. http://id.bnportugal.gov.pt/bib/bibnacional/1918198

Silva, J.D.C. 2020. Anatomia da madeira e suas implicações tecnológicas (In Portuguese). UFV, Viçosa, Brazil.

Torgovnikov, G.; Vinden, P. 2009. High-intensity microwave wood modification for increasing permeability. Forest Prod J 59(4): 84–92.

Torgovnikov, G.; Vinden, P. 2010. Microwave wood modification technology and its applications. Forest Prod J 60(2): 173–182. https://doi.org/10.13073/0015-7473-60.2.173

Weng, X.; Zhou, Y.; Fu, Z.; Gao, X.; Zhou, F.; Fu, F. 2020. Effects of microwave treatment on microstructure of Chinese fir. Forests 11(7): 1-9. https://doi.org/10.3390/F11070772

Weng, X.; Zhou, Y.; Fu, Z.; Gao, X.; Zhou, F.; Jiang, J. 2021. Effects of microwave pretreatment on drying of 50 mm-thickness Chinese fir lumber. J Wood Sci 67(13): 1-9. https://doi.org/10.1186/s10086-021-01942-2

Xiao, H.; Lin, L.; Fu, F. 2018. Temperature characteristics of wood during microwave treatments. J For Res 29(6):1815–1820. https://doi.org/10.1007/s11676-018-0599-4

Yin, J.; Song, K.; Lu; Y.; Zhao, G.; Yin, Y. 2015. Comparison of changes in micropores and mesopores in the wood cell walls of sapwood and heartwood. Wood Sci Technol 49(5): 987–1001. https://doi.org/10.1007/s00226-015-0741-9

Yin, Q.; Liu, H.H. 2021. Drying stress and strain of wood: A review. Appl Sci 11(11): 1-19. https://doi.org/10.3390/app11115023




How to Cite

Mascarenhas, F. J. R., Pereira Geraldes Dias, A. M. ., Christoforo, A. L. ., Manuel dos Santos Simões, R. ., & Palos Cunha, A. E. . (2022). Effect of microwave treatment on drying and water impregnability of Pinus pinaster and Eucalyptus globulus. Maderas-Cienc Tecnol, 25, 1–14. https://doi.org/10.4067/s0718-221x2023000100406




Most read articles by the same author(s)