Investigation of the Rate of Vacuum-Conductive Drying of Wood-Particle Panels Based on Polyvinyl Alcohol

Abstract

Wood composites are promising construction and finishing materials that offer the best properties of both wood and polymers. With the industry's need to use low-toxic adhesives in view, one of the ways to ensure the environmental friendliness of composites is the use of polyvinyl alcohol as a binder. In this respect, in order to streamline production, both in terms of reducing energy consumption and improving the quality of the final product, it is vital to choose the drying rate when pressing panels. The paper presents the results of a study of the process of vacuum-conductive drying of eco-friendly polyvinyl alcohol (PVA)-based wood-particle material. It was found that the composite samples with a PVA content of 40% in terms of physical and mechanical parameters (ultimate bending strength and ultimate tensile strength perpendicular to the panel face) fully comply with the established standards. The study provided the values of drying rate depending on 5 factors. The multi-factor regression analysis method was used to derive equations that determine the drying rate of polyvinyl alcohol-based wood-particle panels for two humidity intervals (above and below the cell walls humidification limit), taking into account the properties of different classes of bodies that make up the composite.