Effect of Face Layer Manipulation on the Density Profile and Properties of Low Density Particleboard

Abstract

Density reduction has gradually become a trend for the particleboard and furniture industries due to increased price and insufficient supply of wood. However, reduced density of the panels by the simple reduction of the wood material comes along with deterioration of the properties. In this study, to achieve sufficient properties (bending properties in particular), the particle moisture content (MC) and geometry in face layers were manipulated to manufacture low density particleboards (500 kg. m-3), with the core layer composed of a mixture of wood particles (92.5 wt %) and expanded polystyrene (7.5 wt %). This strategy was assumed to increase face layer density and generate a more pronounced vertical density profile, which is expected to improve panel properties. The density profile, mechanical properties and dimensional stability of the particleboards were investigated. Results showed that increasing the moisture content of face layer particles from 8% to 16% or using small-sized particle in face layer resulted in a more pronounced density profile, as well as using fiber in face layer. However, the higher density in the face layer was not necessarily related with better mechanical performance. The optimum physic-mechanical properties were obtained with the board of face layer made of 16% MC fiber, which met the requirements for P2 boards used in dry conditions (EN 312).