Ultrasonic plastic welding is to use the high frequency vibration of ultrasonic to accurately seal two thermoplastic materials in sub-second time. Under the high-frequency sound wave pressure, the entire part connection process is realized in less than 0.2 seconds.

The high-frequency vibration of the ultrasonic wave is transmitted to the surface in direct contact with the plastic part. Since the boundary of the welding area has a large acoustic impedance, a high temperature will be generated in a short time. Thermoplastic is a very poor heat conductor, and it is difficult to dissipate its own heat before changing the state of the plastic from solid to liquid. Under pressure, the two parts will be mixed together as if they were a whole. Once the ultrasonic signal stops, the part will harden again. After welding, a clean and strong weld will be formed between the two parts. The strength of the weld is close to the strength of the raw material formed in the weld.

Ultrasonic high-frequency vibration will generate periodic strain in the welding area, thereby generating heat, so that the two plastic parts are melted and welded in some areas. Since ultrasonic vibration acts on the entire welding surface, energy directors are usually added to control melting and reduce the amplitude required to achieve welding.

material selection

Ultrasonic welding can be used in conjunction with a variety of thermoplastics, but it is not compatible with each other or between processes, so please choose carefully. After selecting the material type for the part design, make sure that your supply chain can consistently manufacture parts with strict tolerances (such as injection molds). If you need to change or change the material, it is best to re-evaluate the process with the help of professionals, because you may need to change the welding parameters or even the equipment. Since welding quality and strength are closely related to part design and materials, please realize that even small changes can have a significant impact on the joining process.