Ultrasonic welding is an industrial technique whereby high-frequencyultrasonic acoustic vibrations are locally applied to workpieces being held together under pressure to create a solid-stat weld. It is commonly used for plastics, and especially for joining dissimilar materials. In ultrasonic welding, there are no connective bolts, nails, soldering materials, or adhesives necessary to bind the materials together

Ultrasonic welding  can be used on thermoplastics or fabric .

If you use it for  with textile fusion, ultrasonic welding   can  be used for finishing (fabric edges , cut and weld) or to bond two different material together ( PU and fabric for example) ,ultrasonic welder can be found as handeld dice or fully automated units.