Ultrasonic transducers are devices that convert electrical energy into mechanical energy (ultrasonic waves). The most mature and reliable device that converts electrical energy and acoustic energy by piezoelectric effect is called a piezoelectric transducer. It consists of a central piezoceramic component, a front and rear metal cover, a pre-stressed screw, an electrode pad and an insulating tube. This sandwich transducer (bolt-type transducer) produces stable ultrasonic waves when the load changes, and is the most basic and most important method for obtaining a power ultrasonic drive source. According to different designs, their forms mainly include column type (the front and rear metal cover plates have the same diameter), inverted horn type (the front cover plate diameter is excessively reduced by the arc type), cylindrical steel back cover, and column type intermediate clamp aluminum plate type. 

Ultrasonic transducers are used in conjunction with ultrasonic plastic welding machines to weld plastic products. Ultrasonic plastic welding machines have different welding sizes due to different use occasions and welding materials, and their specifications are also various. Its output power is from manual welding. Tool heads are available with and without amplitude amplification. Plastic welding machine acoustic system tool heads are usually made of aluminum alloy, and the end surface is plated with cemented carbide. Titanium alloy materials can also be used when the power is high. As a result, the fatigue strength of the material is more than twice that of aluminum alloy.

Structure:

1.An ultrasonic stack composed of a converter or piezoelectric transducer, an optional booster and a sonotrode(US: horn). All three elements of the stack are specifically tuned to resonate at the same exact ultrasonic frequency( typically 15,20,30,35 or 40KHz)

     • Converter: converters the electrical signal into a mechanical vibration

     • Booster: modifies the amplitude of the vibration. It is also used in standard systems to clamp the stack in the press.

     • Sonotrode: applies the mechanical vibration to the parts to be welded.

2.An electronic ultrasonic generator(US: power supply) delivering a high power AC sinal with frequency matching the resonance frequency of the stack.