An Innovative Engineered Wood Product Made from Densified Wood with Enhanced Fire Performance – State-of-the-Art

As an environmentally friendly wood-modification method, thermo-hydro-mechanical (THM) densification is being developed to improve the intrinsic mechanical properties of wood. However, there is limited investigation on its scale-up application and fire performance of the resulting product. Therefore, the potential of applying THM densified wood in Engineered Wood Products (EWPs) with enhanced fire performance was explored through a review of related studies. The state-of-the-art indicates the importance of material selection and species specific THM process parameters on the scale-up application. Considering the fire safety, the densification itself slightly influences the reaction to fire of wood while its excellent mechanical properties at room and elevated temperature could be able to improve the fire resistance by provide additional residue load-bearing capacity to keep structural integrity in the fire. To further enhance its fire safety properties through delaying ignition time and decreasing the heat-release rate, fire-retardant impregnation and delignification could be combined with densification. Nevertheless, the impregnation and delignification require a complicated and long processing time, high chemical consumption, and the compatibility increases the environmental footprint of the final product.