Ultrasonic Welding Transducer Manufacturer & Supplier. https://www.bjultrasonic.com/shop/ultrasonic-welding-transducer/ The ultrasonic welding process uses high frequency mechanical sound waves (ultrasonics) to create molecular heat between thermoplastic materials. These high frequency acoustic vibrations are transmitted through thermoplastic material by a sonotrode. Typically two parts are located and supported in a fixture beneath the sonotrode. The sonotrode extends and applies a clamping force (pneumatic) to the parts. Localized frictional heat is generated at the joint area (energy directors) creating a molecular bond between the two parts. Typical operating frequencies are: 20 kHz, 30 kHz and 35 kHz.