Production of Layered Wood Composites with a Time-Saving Layer-By-Layer Addition

Multilayered wood composites were manufactured by introducing a cyclic pressing manufacturing method in which plies were added subsequently between each cycle as an alternative to the conventional single-cycle method based on a continual pressing of an entire set of veneers. The goal of the proposed cyclic method was to reduce the pressing time of multilayer wood-based composites. Scots pine veneers with two different moisture contents (5% and 10%) were selected. Heat transfer dynamics showed that the heat transfer through the veneers was remarkably dependent on the moisture content of the veneers, so the pressing time of the veneers with higher moisture content can be easily reduced. The density profile showed that by adding layer by layer, the density of the core is higher than that of the external layers. However, the mechanical tests of the composites produced by cyclic-pressing showed that the bending strength and modulus of elasticity, as well as the internal bond of composites were similar and in some cases even higher than composites pressed in a conventional way, while having pressing time reduced to less than a half.