Ultrasonic welding is particularly suited for assembling medical devices because it uses the device material itself to create the joint, obviating the need for adhesives. A fast, clean, efficient and repeatable process, ultrasonic welding is ideal for joining just about any plastic parts for many applications. To obtain these advantages, however, engineers must select a weldable material, design the joint, develop the fixtures, optimize the welding process, and finally, control it.
Ultrasonic welding joins thermoplastic parts by using high-frequency vibration (typically 20 to 40 kilohertz) to melt material at the junction of the parts. First patented in the 1960s, ultrasonic welding has since been refined for use in many applications. Related processes include ultrasonic staking, swaging and spot welding.