... Scope: riveting, spot-welding, and folder positioning Spot welding machine by hand1, Principle:Principles of ultrasonic welding generator 28KH by high ... vibrations, by virtue of the energy communicated to the welding head on the plastic piece so that it produces ... weld. 2, the application scope:Plastic & metal riveting, spot welding, embossing, folders positioning technology. 3, features:1. Small size, ...