POSSIBILITY STUDY ON HYBRID PROCESS FOR HDPE WELDING

Abstract

Welding of polymer would require both heat of melting and pressure during welding. However, pressure provided also deteriorates strength of welded joint by creating stringer parallel to welded boundary. In this study, dual sources of heating as well as pressure were combined and proposed as a hybrid welding system. An infrared lamp together with friction stir was the heat source for welding. Friction stir tool was also acted as mixing tool to stir molten polymer and blend it in order to prevent formation of stringers at the interface. The system designed was to control travel speed and infrared heating power by feedback control from a pyrometer measuring temperature at the proximity to be welded. Spindle speed of a stir tool was fixed for this study and the tool was in a cylindrical shape. Specimens used in this study were HDPE plates with thickness of 5 mm. The results showed that the hybrid welding system could be used to generate sufficient heating to melt HDPE specimens and blend it creating welded joints.