Welding Methods of Polymer Composites

Abstract

Mechanical fasteners, adhesives and welding processes are used to join polymer composites. Although the mechanical joining process is carried out quickly, sealing cannot be achieved due to the holes drilled in the parts and high local stresses occur near these holes. A better stress distribution can be achieved with adhesive bonding, but they are difficult to apply and the processing time is long. Besides, adhesive selection and preparation and surface cleaning are vital for the strength of the joint in adhesive connections. When it is desired to obtain values close to the mechanical properties of the base material, welding comes to the fore. Furthermore, the processing times are short and it is also possible to provide sealing. Since welding of polymer-based materials is mostly carried out using heat, especially thermoplastic polymers can be welded. Thermoplastic materials can be softened and hardened repeatedly by heat, whereas thermoset polymers cannot be softened by reheating once hardened and therefore cannot be welded using heat. In this study, traditional fusion welding methods used in welding polymer composites and a new welding method that does not use heat are explained.