main functions of an automatic ultrasonic machine in welding

The initial contact area on the welding interface (fusion surface) of an automatic ultrasonic 

machine is intentionally kept small to ensure deformation (strain) of the welding interface. 

The automatic ultrasonic machine ensures uniform heating across its entire surface, quickly

 reaching the melting temperature of thermoplastic materials and facilitating energy conversion.

 The design of the welded components aims to increase the contact area between them to 

reduce the potential for localized high stress at the welding joint/welded part, thus minimizing

 the risk of scratching the welded part. Additionally, the design of the welded components aims

 to minimize the distance between the contact area of the welded part, the welding joint, and the 

welding surface while ensuring that this distance remains constant throughout the welding 

process. It is essential to avoid gaps; otherwise, the vibrations of the automatic ultrasonic 

machine will not directly transmit to the welding surface.

The welding distance (the distance between the contact area of the welded part/welding joint 

and the welding surface) is considered in the design of the automatic ultrasonic machine. If 

the distance is less than 6mm, it is referred to as "near-field welding," while distances greater 

than 6mm are termed "far-field welding." It should be noted that if the welding distance is less

 than the wavelength of the welding material, the automatic ultrasonic machine is suitable for

 near-field welding. For near-field welding, it is typically assumed that the amplitude of the energy 

controller is similar to the amplitude of the welding joint. Conversely, in far-field welding, wave 

propagation within the welded components needs to be considered when determining the amplitude 

experienced by the energy controller of the automatic ultrasonic machine. If possible, the design 

of the welded components should be tailored for near-field welding to reduce issues such as 

scratching, energy loss, component deformation, and equipment overload. If near-field welding

 cannot be designed, careful consideration should be given to the dimensions of the welded 

components to ensure a larger surface amplitude for the weld. The design of the welded components

 provides three critical prerequisites for the success of the automatic ultrasonic machine.