Forest and Wood Products

Forest and Wood Products

Investigation of the thermo-physical performance of sandwich panels with MDF skin and Paulownia wood-polyurethane foam hybrid core

Document Type : Research Paper

Authors
Hossein Manouchehri 1
Payam Moradpour 1
Mosayeb Dalvand 1
Carsten Mai 2
1 Department of Wood and Paper Science and Technology, Faculty of Natural Resources, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
2 Department of Wood Biology and Wood Products, University of Göttingen, Göttingen, Germany.
10.22059/jfwp.2025.399220.1360
Abstract
In this study, the physical properties and thermal performance of lightweight sandwich panels with a hybrid paulownia wood–polyurethane foam core were investigated. The type of core (honeycomb, continuous lattice, and discontinuous lattice) and the core composition (with and without polyurethane foam) were selected as variable factors. MDF with a thickness of 3 mm was used as the skin of the sandwich panels. Panels were manufactured according to the experimental design, with dimensions of 90 × 60 × 3.1 cm. After manufacturing, test samples were prepared and evaluated for density, water absorption, and thermal properties. Results showed that the density of panels with continuous and discontinuous lattice cores increased by about 30% and 50%, respectively, compared to the honeycomb core (control), while remaining within the allowable limit for lightweight panels. Water absorption results indicated that panels with a honeycomb core without foam had the highest absorption (84.3%), while panels with a continuous lattice core with foam had the lowest (52.5%). The use of polyurethane foam increased panel density, reduced water absorption, and significantly improved thermal insulation. The continuous lattice core containing foam, with a thermal conductivity of 0.043 W/m·K, was selected as the optimal treatment for thermal insulation. Despite the increased density of wood-core sandwich panels compared to the control, they still fall within the lightweight panel category. Therefore, their use as thermal insulation panels is recommended.
Keywords
Continuous lattice
Discontinuous lattice
Honeycomb
Thermal insulation
Subjects
  • Ma, Q., Rejab, M.R.M., Siregar, J.P. & Guan, Z. (2021). A review of the recent trends on core structures and impact response of sandwich panels. Journal of Composite Materials, 55(18), 2513-2555.
  • Brockmann, W., Geiß, P.L., Klingen, J. & Schröder, K.B. (2009). Adhesive bonding: materials, applications and technology. John Wiley & Sons.
  • Monteiro, S., Martins, J., Magalhães, F.D. & Carvalho, L. (2017). Lightweight wood composites: challenges, production and performance. In Lignocellulosic Composite Materials (pp. 293-322). Cham: Springer International Publishing.
  • Ahmad, F., Choi, H.S. & Park, M.K. (2015). A review: natural fiber composites selection in view of mechanical, light weight, and economic properties. Macromolecular Materials & Engineering, 300(1), 10-24.
  • Alavez-Ramirez, R., Chiñas-Castillo, F., Morales-Dominguez, V.J. & Ortiz-Guzman, M. (2012). Thermal conductivity of coconut fiber filled with ferrocement sandwich panels. Construction & Building Materials, 37, 425-431.
  • Knox, E. M., Cowling, M.J. & Winkle, I.E. (1998). Adhesively bonded steel corrugated core sandwich construction for marine applications. Marine Structures, 11(4-5), 185-204.
  • Castanie, B., Bouvet, C. & Ginot, M. (2020). Review of composite sandwich structure in aeronautic applications. Composites Part C: Open Access, 1, 100004.
  • Sharma, P. & Kumar, V.R. (2022). Energy analysis in residential buildings for insulation roof material using building information modelling. Journal of Engineering Research, 10.
  • Yihan, X. U. E. (2016). Review of Thermal Insulation Materials for Pipelines. Scholars Journal of Engineering and Technology (SJET), 4(5), 258-260.
  • Boafo, F.E., Kim, J.H., Ahn, J.G., Kim, S.M., Kim, J.T. & Zhang, L. (2022). Study on thermal characteristics and electrical performance of a hybrid building integrated photovoltaic (BIPV) system combined with vacuum insulation panel (VIP). Energy & Buildings, 277, 112574.
  • Qi, C., Zhang, F., Mu, J., Zhang, Y. & Yu, Z. (2020). Enhanced mechanical and thermal properties of hollow wood composites filled with phase-change material. Journal of Cleaner Production, 256, 120373.
  • Zhang, H., Fang, W.Z., Li, Y.M. & Tao, W.Q. (2017). Experimental study of the thermal conductivity of polyurethane foams. Applied Thermal Engineering, 115, 528-538.
  • Ahmad, F., Choi, H. S., & Park, M. K. (2015). A review: natural fiber composites selection in view of mechanical, light weight, and economic properties. Macromolecular Materials and Engineering, 300(1), 10-24.
  • Critchley, R., Corni, I., Wharton, J A., Walsh, F.C., Wood, R.J. & Stokes, K.R. (2013). A review of the manufacture, mechanical properties and potential applications of auxetic foams. Physica Status Solidi (b), 250(10), 1963-1982.
  • Wei, X., Xiong, J., Wang, J. & Xu, W. (2020). New advances in fiber-reinforced composite honeycomb materials. Science China Technological Sciences, 63(8), 1348-1370.
  • Harikrishnan, G. (2007). Polyurethane foams: processing and material development (Doctoral dissertation, Indian Institute of Technology, Bombay (India)).
  • Pau, D.S.W., Fleischmann, C.M., Spearpoint, M.J. & Li, K.Y. (2014). Thermophysical properties of polyurethane foams and their melts. Fire & Materials, 38(4), 433-450.
  • Fan, H., Tekeei, A., Suppes, G.J. & Hsieh, F.H. (2012). Physical properties of soy‐phosphate polyol‐based rigid polyurethane foams. International Journal of Polymer Science, 2012(1), 907049.
  • Brinker, S., Ahrens, C., Gurnik, M., Mayer, A.K, & Mai, C. (2025). Influence of screened fibre fractions on the properties of insulation panels made of different wood species. Wood Material Science & Engineering, 1-11.
  • ASTM International. (1932). Standard test methods of evaluating properties of wood-based fiber and particle panel materials (ASTM D1037-32). ASTM International.
  • ASTM International. (2016). Standard test method for density of sandwich core materials (ASTM C271/C271 M-16). ASTM International.
  • ASTM International. (2024). Standard Test Method for Water Absorption of Core Materials for Sandwich Constructions. (ASTM C272/C272 M-18). ASTM International.
  • Deutsches Institut für Normung. (2001). Thermal performance of building materials and products – Determination of thermal resistance by means of guarded hot plate and heat flow meter methods – Products of high and medium thermal resistance (DIN EN 12667:2001). Beuth Verlag.
  • ASTM International. (2021). A standard test method for steady-state thermal transmission properties is by means of the heat flow meter apparatus (ASTM C518-21). ASTM International.
  • Deutsches Institut für Normung. (2012). Characterization of waste – Leaching behaviour test cases (DIN CEN/TS 16368:2012). Beuth Verlag.
  • Brombacher, V. (2015). Untersuchungen zur Optimierung von Holzfaserdämmstoffen in Abhängigkeit von Rohstoff, Herstellverfahren und Aufschlussbedingungen (Doctoral dissertation, ETH Zurich).
  • Imken, A.A., Plinke, B. & Mai, C. (2021). Characterisation of hardwood fibres used for wood fibre insulation boards (WFIB). European Journal of Wood & Wood Products, 79, 915-924.
  • Park, B.D., Kim, Y.S. & Riedl, B. (2001). Effect of wood-fiber characteristics on medium density fiberboard (MDF) performance. Journal of the Korean Wood Science & Technology, 29(3), 27-35.
  • Deutsches Institut für Normung. (2020). Thermal insulation and energy economy in buildings – Part 4: Thermal and moisture protection values for building materials and products (DIN 4108-4:2020). Beuth Verlag.
  • Thermal insulation products for buildings - Factory-made wood fibre (WF) products - Specification; German version EN 13171:2012+A1:2015
  • Imken, A.A., Kraft, R. & Mai, C. (2022). Production and characterization of wood-fibre insulation boards (WFIB) from hardwood fibers and fibre blends. Wood Material Science & Engineering, 17(6), 802-808.
Forest and Wood Products
Volume 78, Issue 2
Summer 2025
Pages 163-176