Ultrasonic welding is a process involving the application of transducer technology and acoustic energy to thermally join together two components. Ultrasonic welding is used throughout many industries to join materials such as plastics, metals and composites. In plastic ultrasonic welding, heat is generated by the friction caused by the high-frequency vibrations of the two mating surfaces, which melt the plastic and produces a weld.
Ultrasonic welding is a relatively fast and low-cost technology that can be used to join a variety of materials. It is also a simple and reliable process. This process is employed where high-strength bonds are needed between two materials, as it can join them in a matter of seconds.
The process of ultrasonic welding begins with the components that need to be joined being placed in the appropriate fixture or jig. The fixture must be designed to couple the ultrasonic energy from the tooling to the components to be welded. The fixture itself must be strong enough to handle the force of the ultrasonic vibration without being damaged and must be correctly designed to direct the plastic weld joint correctly. The components are held by the fixture in a precise location relative to one another so that the two mating surfaces are touching.
The next step is for the ultrasonic tooling to be applied to the components. This ultrasonic tooling usually consists of two parts, a transducer and a horn. The transducer contains a high frequency signal which is converted into vibrations by the horn. As the signal from the transducer passes through the horn, the horn amplifies the signal, creating mechanical vibrations. These vibrations cause thermal energy to be transmitted to the materials, resulting in them melting and forming an interstice that is composed of both components. Once the tooling is applied and the parts have been joined, a cool-down stage is occur and the weld is complete. The duration of this cool-down is related to the material melted as well as the size and shape of the weld joint.
The advantages of using ultrasonic welding compared to traditional methods include a fast, repeatable and environmentally friendly process, as well as a strong bond and no filler material being needed. Ultrasonic welding can also be used with a variety of materials, providing higher strength welds than other thermal joining methods such as adhesive or ultrasonic spot welding. It is important to note however, that this technology may not be suitable for all types of plastics due to their different properties.
Ultrasonic welding is an efficient, low-cost and environmentally friendly technology that can be used to join plastics and other materials. This method is most effective when the materials being joined have similar properties, and when the fixture, tooling and parameters are correctly chosen.
