Engineering properties of wood-plastic composite panels

Abstract

Over the past decade, there has been a growing interest in the development of consumer and industrial products composed of wood fillers combined with thermoplastic resins. The use of wood flour as a reinforcing filler for thermoplastics has several benefits. Wood fillers have the advantage of being renewable, inexpensive, lightweight, and non- abrasive to processing equipment. Both materials can be obtained from post-consumer or post-industrial recycling sources. Little information is available concerning the engineering characteristics of wood- plastic composite panels. Recently. there has been an increasing interest in using this type of material for a variety of structural applications. To quantify the material performance, several different wood-flour thermoplastic formulations ranging from 0% to 60% wood filler content by weight were produced and tested according to the ASTM D 1037 standard for wood-based panels. A matched set of specimens underwent the accelerated aging process outlined in the standard. It was found that by increasing the ratio of wood filler, the material performance properties were altered. The modulus of elasticity and water absorption increased, while the coefficient of thermal expansion and ultimate stress values decreased. The aging process had very little effect on the 0% wood filler content samples and decreased the material performance in some properties for the higher wood percentage panels. The results were compared with conventional wood-based panel products. Included were particleboard, hardboard, plywood, medium density fiberboard, and oriented . strandboard. Though the stiffness of wood-plastic composite panels were generally less than conventional wood-based products, many other material properties were similar.