Ultrasonic vibration is required to be transmitted to the upper part of the assembly through the welding joint, and finally to the joint or interface of the two parts. Here, the vibration energy is converted into heat energy to melt the plastic. When the vibration stops, the plastic solidifies under pressure and produces welding on the joint surface, It is important to obtain the best welding results. There are a variety of connection designs, each with its own features and advantages. The use of various designs depends on many factors, such as the type of plastic, the geometry of the part, the welding requirements (i.e. viscosity, strength, sealing, etc.)