When engaging in ultasonic welding, there are two options to choose from: the longitudinal method and the torsional method. The method you should use is based on the results that you are trying to achieve. With the wrong system, you might risk damaging one of the materials you're working with.
The Longitudinal System
With the longitudinal system, the system is arranged in a vertical fashion. Vibrations are applied to the pieces. The pressure is created by a cylinder that applies vibrations to connected pieces. One part is placed on top of the other part. Then, a titanium component known as the horn comes in contact with the upper part. Pressure is applied to both parts, clamping them together. Then, the horn is vibrated tens of thousands of times per second. The energy is applied to points of contact. The vibrations create heat through friction. The two parts are clamped in order to ensure that they fuse together.
The Torsional System
One of the problems with the longitudinal system is that the vibrations may cause problems under some applications. Therefore, it may be necessary to instead use high-frequency friction welding. While vibrations are applied, they are applied intermittently. Unlike with the longitudinal system, the torsional system does not apply any pressure on the lower half of the piece. When working with sensitive parts, there is a risk that they might be damaged through the longitudinal method. This approach also makes it possible to join different plastics together. Otherwise, the process is similar to that of the longitudinal system.
An example of why ultrasonic plastic welding is so helpful is with the creation of microcircuits. Ultrasonic welding can create great bonds without introducing impurities or distorting the components. This makes it possible to create very small microcircuits that can be used for applications such as monitoring a human heart. When using other welding processes, it can be difficult to join materials that are not similar. This can be very useful when creating batteries.
Ultrasonic welding is helpful in the medical industry because it allows for products to be welded without introducing contaminants. Because the process is very automated, it is less likely to introduce contaminants as a result of human error. This welding process does not interfere with the bio-compatibility of parts. However, medical materials are very sensitive, so it may be necessary to use the torsional method rather than relying on the longitudinal system.
For more information, talk to a professional like MarTech Sales & Associates.