Abstract: The present invention relates to a particle board comprising a lower and an upper surface layer (9, 11) having a finer fraction of particles (4), and between these surface layers (9, 11) an intermediate layer (13) having a coarser fraction of particles (5). The intermediate layer (13) has a varying density.

Abstract: The invention relates to a structural member comprising a first and a second board member that are arranged in parallel to each other, and a filler element arranged between the first board member and the second board member. The filler element is a continuous sheet with a sheet plane that is substantially parallel to the first and second board member, and is moulded or vacuum-moulded so that cone-shaped cavity structures project outward from the sheet plane. The cone-shaped cavity structures are provided as truncated cones having a top and bottom, both having a substantially circular shape. One side of the sheet plane has a continuous, flat surface and the cone-shaped cavity structures project outward on the other side of the sheet plane. The cone-shaped cavity structures have a cone angle of approx. 5-45°.

Abstract: The present invention relates to a particle board comprising a lower and an upper surface layer (9, 11) having a finer fraction of particles (4), and between these surface layers (9, 11) an intermediate layer (13) having a coarser fraction of particles (5). The intermediate layer (13) has a varying density.