1. To adapt to different products: ultrasonic welding through vibration to connect plastic parts, the higher the frequency, the smaller the amplitude, the smaller the corresponding power.

Therefore, the high frequency (40khz/35khz) welder is used for the welding of plastic parts with small size and precision welding; 28khz welder is mostly used for hand-held spot welder, and 20khz/15khz ultrasonic welder is used for welding large and complex plastic parts. The power is about high, the power of the ultrasonic machine is smaller, the lower the frequency, the greater the power of the ultrasonic welding equipment.

2. Different sizes of ultrasonic molds: the most common ultrasonic molds are half-wave welding heads. Lengths and sizes of ultrasonic welding molds with different frequencies are also different, such as 40k mold (7cm), 35khz (8cm), 28khz (10cm), 20khz mold (13cm) and 15khz mold (17cm).

3. Ultrasonic transducer structure is different: high-frequency welder (40khz, 35khz, 28khz) transducer structure is split (transducer + transformer for a separate part), desktop ultrasonic welder (20khz, 15khz) ultrasonic transducer structure is integrated (transducer + transformer) for the whole part.