Technology: Ultrasonic Plastic Welding

Ultrasonic plastic welding uses high-frequency vibrations applied to thermoplastic parts being held together under pressure to create a permanent bond at their interface. The process requires no consumables, is fast, and uses less energy than typical alternative joining methods.

An ultrasonic welding system is comprised of:

Power Supply - A unit that produces a high frequency electrical signal which is delivered to the converter. Additionally, the Power Supply controls the system's sequence of operation and duration of weld.
Converter - An assembly of piezoelectrics that converts the Power Supply's electrical signal into mechanical vibration.
Booster - Connects the horn to the converter and can modify the amplitude of vibration based on its machined geometry.
Horn - Custom tool that applies the mechanical vibration to the thermoplastic parts being welded.
Actuator - Method of housing the ultrasonic stack (converter, booster, horn) and applying pressure via pneumatics to the thermoplastic parts being welded.

Ultrasonic welding systems are available in different frequencies (e.g., 15 kHz, 20 kHz, 30 kHz, 40 kHz, 60 kHz). Each frequency has benefits and negatives. For example, 15 kHz is beneficial for large parts or far field welding, whereas 40 kHz is beneficial for small parts or near field welding. When welding two rigid components, consideration for the joint design must be undertaken at the part design stage. Ultrasonic plastic welding is used in many industries such as electronics, aerospace, automotive, medical, packaging, consumer goods, and food processing.

Click the "A" Application button to view examples of ultrasonic welding applications.