Effects of Long-term Storage on the Mechanical Characteristics of Wood Plastic Composites Produced from Thermally Modified Wood Fibers

In order to study possible changes in the mechanical properties of wood plastic composites produced from thermally modified wood fibers as reinforcement material (60%) and polypropylene (40%) after long-term storage under constant conditions, tensile and flexural specimens were tested in the years 2004 and 2009 after storage at 20°C and 65% humidity. Increased tensile strength, Young’s modulus (tensile test) as well as modulus of elasticity (flexural test) were observed for the long-term stored samples indicating a positive effect of the storage conditions on the mechanical properties of the samples.