Unidirectional fiber reinforced tapes as energy director for the ultrasonic welding of thermoplastic composites

Ultrasonic welding is a very promising technology for the welding of fiber reinforced thermoplastics. The ultrasonic waves are absorbed by the material and melt up the matrix material by molecular and interface friction. Energy directors concentrate the ultrasonic energy and enable a controlled melting of the joining area. But the manufacturing and application of such energy directors on thermoplastic composites is complex and need lot of effort. By using narrow unidirectional fiber reinforced tapes as energy directors on contrary already existing material, machinery and processes can be used.