What is ultrasonic welding?

Ultrasonic welding works on the principle that two materials can be subjected to high-energy vibrations, generating frictional heat. The horn in the diagram is shaped to apply vibratory energy to selected joint areas. This heat plasticizes the two workpieces, and when pressure is applied, the materials mix at the weld zone. When the vibrations stop, the combined material cools and solidifies to form a strong, homogenous bond. It is the cheapest and fastest plastic welding process, so engineers often favor it.