Continuous Ultrasonic Welding of Thermoplastic Composite Plates

Abstract

Ultrasonic welding is a very promising technique for assembling thermoplastic composite structures because it features extremely short heating times and very low energy consumption, as well as suitability for in-situ process monitoring. Continuous ultrasonic welding of plastic films, fabrics and thermoplastic composite prepreg tape is common in industry. However, continuous ultrasonic welding of stiff thermoplastic composite plates is challenging due to the lack of local deformation of the welding stack preventing flow of resin at the welding interface. This paper presents a novel approach to continuous ultrasonic welding of thermoplastic composites based on zeroflow welding. The proposed technique can create high quality welds before little to no squeeze flow at the interface occurs. It is made possible by the use of very thin flat energy directors, owing to simultaneous melting of both energy director and adherends’ matrix. The results prove the feasibility and indicate the potential for highstrength welds between thermoplastic composite plates at very high speed.