Robotic ultrasonic plastic welding

Ultrasonic welding, for thermoplastic injection moulded components, is a process that uses mechanical vibrations above the audible range. The vibrations, produced by a welding sonotrode or horn, as it generally is known, are used to soften or melt the thermoplastic material at the joint line.

This process has become the standard practice within the automotive industry, by which plastic parts are “welded” together. Parts such as dash boards, center consoles and door panels all consist of multiple plastic parts (some covered in various fabrics & materials) that need to be bonded together to form a complete part. With holes in one part through which studs protrude from another, the ultrasonic sonotrode melts the stud to form a mushroom head and by doing so, bonds the parts together.

This process can be performed manually or via automated machinery such as in this case, where Robotic Innovations was contracted to supply two turnkey robotic ultrasonic welding solutions. The separate parts are sequentially loaded into a nesting fixture by an operator. Upon activation of the process start, the safety cage moves down and the robot ultrasonically welds the parts together ensuring perfect depth of weld, positional accuracy at a speed not possible manually.