Effect of Preheating Conditions on the Mechanical Reliability of HDPE Extrusion-Welded Structures for Medical Devices

Polymers are increasingly used as structural materials in medical devices due to their lightweight, chemical resistance, and electrical insulation properties. High-density polyethylene (HDPE) is widely applied; however, the fabrication of large or thick components often requires extrusion welding. Since joint performance directly affects structural reliability, controlling welding quality is essential. In this study, the effects of preheating conditions on the mechanical performance of HDPE extrusion-welded joints were systematically investigated. Preheating temperature and hot-air movement speed were selected as key variables, and their influence on tensile, flexural, and elongation properties was evaluated experimentally. The results provide insight into the role of preheating in weld quality and offer guidance for process optimization in medical device applications.