WELDING OF RECYCLED THERMOPLASTIC LUMBER FOR STRUCTURAL COMPONENTS

摘要

This paper reviews experimental work on welding of reinforced recycled thermoplastic lumber for the fabrication of structural components. Recently the use of thermoplastic lumber has become more accepted due to the materials longevity. However, because of extrusion difficulties, such as shrinkage holes and long cooling times, plastic lumber has not been widely used for structural components, such as pilings and supports. In order to solve some of these issues, it has been proposed to extrude standard, relatively small cross sectional components, such as 2x4 and 2x6, and join these components into larger structural components, such as 6x6 to 10x10 or engineering components such as I-beams. This work evaluated a wide range of welding processes, including; hot plate, vibration, IR and non-contact hot plate welding as well as adhesive bonding. Star design of experiments was conducted for each process and relevant parameters. Process optimization was preformed for each process in order to minimize cycle time and maximize weld strength. In addition, flexural tests of selected samples were performed. It was found that welding could produce joints as strong and as stiff as the base material.