Ultrasonic waves are sound waves above the limit of human hearing and can be put to practical use in manufacturing everything from car computers to medical equipment. This is because these vibrations cause plastics and thin layers of metals to melt in predictable and controllable ways which can be channeled into a weld. The equipment and process for ultrasonic welding are highly specialized, easily adapted for automation and provide quality welds.
To use this type of welding, you will need some basic equipment such as Dukane ultrasonic converters, boosters, horns, and anvils or fixtures to hold the items being welded together. You will also need a power supply and a way to apply pressure to the pieces. The type of fixture and pressure will largely depend on which materials you are using and the sizes of each piece. Those same factors will change the way your computer or microprocessor configures the frequency, temperature and pressure of this process as well as the timing and how the waves are directed.
The process of ultrasonic welding can be boiled down to some basic steps. The parts to be welded are placed on the fixture and the horn contacts the materials. Pressure is applied to keep the horn and parts in place, usually air pressure from a pneumatic arm. The horn then emits sound waves either up-and-down or side-to-side for the length of time dictated by the materials being used. Once the weld is set, the horn and materials can be removed. For metals, the sound waves are applied parallel to the plane of the materials, and the metal is heated but not melted. This removes films and metal oxides from the surface and allows the molecules to flow between parts to form the bond. Plastics, on the other hand, have ultrasonic waves applied perpendicular to the plane of the materials to melt and fuse the parts together.
Ultrasonic welding harnesses the vibrations of sounds above the limit of human hearing to bond plastics and metals together. Manufacturers use this type of welding to make electronic components, medical equipment, and even shoes or toys.