The National Science Fair

Ultrasound

Welding by ultrasound or ultrasonic is a modern and avant-garde technology applied on an industrial scale in which Sonic vibrations, characterized by its high frequency, which are applied to parts that are United under pressure thus creating a solid-state welding among them are generated. Ultrasonic welding is used to join different materials, and its use is widespread in the processes for plastics joining. The energy input required to make joints using welding by ultrasonic is obtained with the generation of mechanical vibrations, making unnecessary nails, adhesives, screws or other materials. Ultrasounds also have application in industrial operations aimed at cutting of plastics and rubber. Teams for ultrasonic welding equipment for ultrasonic welding are mainly by the generator, the piezoelectric inverter and the sonotrode. An intelligent computer system adapts the parameters to optimize the welds and allow their storage.

The generator generates electrical oscillations at high frequencies (15-40 kHz) that are transformed by the piezoelectric inverter in ultrasonic mechanical vibration. The powers that reach ultrasonic equipments range between 1, 5 and 3 kW. The sonotrode is made in aluminium and titanium. Each type of welding in need a specific sonotrode for each case should be the resonance of the sonotrode suit frequencies desired through the tuning of the instrument. The sonotrode transmits vibrations to the parts to weld, which remain fixed and pressed, producing a friction which raises the temperature in few tenths of a second. The heat produced is proportional to the amplitude of ultrasonic waves.

Welding of plastics ultrasonic welding of plastics ultrasonic is one of the most advanced techniques and with higher yields. Plastics ultrasonic Assembly is the welding process or the reforming of thermoplastics by heat generated by high frequency mechanical vibrations. In the case of plastic, as vibrations are introduced vertically. Ultrasonic welding process produces a thermal increase in area to form the union. The temperature increase is due to the absorption of mechanical vibrations and friction between the parts. Once produced its merger, plastic parts maintained under pressure manage their molecular union to cool down. The use of ultrasounds in the industry is diverse, as measurements of thickness of metal parts and detection of defects in its structure, automatic openings, etc. Ultrasonic welding of metals by ultrasonic welding applied to the union of metals is an entirely different process to the ultrasonic welding of plastics. Metals welded not heated to melt, they are connected by the application of pressure and the high-frequency mechanical vibrations. In contrast to plastics welding, mechanical vibrations used during ultrasonic welding of metal are entered horizontally. Original author and article source