Stiffness modelling of particles in the core layer for the manufacturing of wood-reduced particleboard

A great demand for wood material has led to an increase in the price of industrial wood in the past and will raise it even further in future. Industry and research have reacted to this increasing price of wood, for example, by developing weight-reduced particleboard. One approach to achieve this reduction in weight is to use suitable chip geometries in the core layer instead of lightweight, resource-saving filling materials. The geometry of the chips in the core layer must have a high compression resistance here to reach the desired apparent density profile. For this purpose, particle geometries were analysed with regard to this property within a project for the development of weight-reduced particleboards. After determining the curve of the compression resistance, it was possible to establish an equivalent spring stiffness model for different chip geometries to characterise the geometry during compression. Merely due to a low bulk density for chips in the core layer, it is not possible to increase the spring stiffness and hence to reach a required apparent density profile. Only compression of the chips leads to a rapid increase in spring stiffness.