New wood-based panel with imprinted 3D surface pattern and improved internal bonding

This research is on a new development towards three-dimensional surfaces for wood-based panels, i.e., particleboards (PB). By imprinting a self-designed stainless steel grid on both sides of PB the following research questions were investigated: (1) feasability of the 3D-pattern imprintment during hotpressing of resinated PB furnishes, (2) assessment of mechanical properties of imprinted PB, and (3) finite element modelling to understand and optimize material properties, including veneer-added sandwich panels. Following a factorial experimental design PB were produced in the laboratory and cut specimens were tested according to standards. As a result, the 3D-pattern imprintment resulted in a much higher internal bonding: For the 500 kg/m³ PB the IB increase was 35 %, while for the 700 kg/m³ the increase was even 67 %. The vertical density profile showed a roof-like shape, with a high density level in the core layer. Bending strength and stiffness turned out to be much lower than for the control. Through finite element modeling (FEM) these property changes could be mechanically explained. A successful compensation for the reduced bending performance could be demonstrated through two-side veneer sheet additions. FEM is also shown to be instrumental for the property optimization of the 3D-pattern imprinted PB. Since IB has significantly increased, the overall PB density could be reduced, meaning a light panel is required for the same product performance. The new 3D-pattern imprinted PB also constitutes a decorative design feature, which could lead to various product applications. Since the imprintment process is easy to execute, this new PB product option might be easily adopted by industry.