What is ultrasonic welding?

Ultrasonic welding of thermoplastic materials is a weld technology utilizing mechanical vibrations to generate heat due to molecular friction. These vibrations excite the molecules in the plastic so that they start moving. The plastic becomes soft and starts melting. The components are bonded by cohesive or form-fit joints After a short hold time under pressure, they are firmly joined molecularly.


Ultrasonic weld technology

Ultrasonic joining technology has been established as joining method for technical thermoplastic materials in a large variety of applications throughout the plastic-processing industry.

Due to:

  • high process speeds
  • repeatable weld results

the technology is preferred for high-volume production in the automotive, electrical, medical, packaging, hygiene, and filter industry.

Good bonding quality in terms of strength, tightness and visual appearance are particularly achieved if the part material and design is suited for the ultrasonic process. This means that from the beginning they must be designed such that ultrasonic waves are focused in the weld zone.

  • The factors below control the weld process:

    Component and ultrasonic weld factors
    Component and ultrasonic weld factors
  • This is an example of a tongue -and- groove weld:

    • Unwelded condition – ultrasonic welding
      Unwelded condition
    • Welded condition – ultrasonic welding
      Welded condition


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