How does ultrasonic welding work? The principle of ultrasonic welding is that an ultrasonic generator converts 50/60 Hz electrical current into 15, 20, 30, or 40 kHz electrical energy. This high-frequency electrical energy is then converted back into mechanical motion of the same frequency by a transducer, which is subsequently transmitted to the welding head through a set of amplitude modulator devices that can change the amplitude. The welding head transfers the received vibrational energy to the joint area of the parts to be welded, where the vibrational energy is converted into thermal energy through friction, melting the plastic. Ultrasonic waves can not only be used to weld hard thermoplastic materials but also to process fabrics and films. The main components of an ultrasonic welding system include an ultrasonic generator, a transducer/amplitude modulator/welding head triad, molds, and a frame. How does linear vibration friction work? Linear vibration friction welding uses frictional heat generated at the contact surfaces of two parts to melt the plastic. The heat comes from one part moving back and forth on another surface with a certain displacement or amplitude under a certain pressure. Once the desired level of welding is reached, the vibration stops, and there is still some pressure applied to both parts, allowing the newly welded section to cool and solidify, thus forming a tight bond. How does orbital vibration friction work? Orbital vibration friction welding is a method that uses frictional heat to weld. In orbital vibration friction welding, the upper part of the workpiece moves in an orbital motion at a fixed speed—circular movement in all directions. The movement generates heat, which causes the welding parts of two plastic pieces to reach their melting point. Once the plastic begins to melt, the movement stops, and the welded parts of the two workpieces will solidify and be firmly connected together. A small clamping force will cause minimal deformation of the workpiece, and workpieces with diameters up to 10 inches can be welded using orbital vibration friction.