The latest advances in ultrasonic welding for medical devices are driven by the need to assemble plastic parts that tend to be smaller and lighter in weight, thinner-walled, and often more contoured than in the past. A growing number of these parts also contain embedded electronics and sensors that require special care in the ultrasonic welding process.

Meeting the medical device industry’s demand for repeatable, strong and consistent welds in these smaller and more delicate components has required the development of improved ultrasonic welding technology. Perhaps the most important recent improvement has been the development of new, more precise methods of force control. This has required a series of changes to the ultrasonic welding actuator and its microprocessor controls.

To achieve the greater and more precise levels of force control required, the developers of Branson ultrasonic welding technology considered not only the capabilities of pneumatic actuators—which remain an industry standard—but also the rapidly advancing capabilities of servo control and technology.

Their solution was a new electromechanical actuation system. A key attribute of this new welding platform and its advanced actuation system is substantially more precise and responsive force control through the entire weld process. Downforce is necessary to maintain horn/part contact and ensure the smooth, efficient transmission of ultrasonic energy into the mating parts. Managing downforce more rapidly and precisely has important implications for weld quality.