Plastics Industries

SONOTRONIC specialises in joining injection moulded and extruded plastic parts. For this, we deploy either ultrasonic, infrared or heated tool technology, depending on the application.

We offer solutions for creating bonded joins. The same or similar plastics can be welded together very tightly using ultrasound, infrared or heated tool. Our technologies are also suited to thermal transforming processes, such as riveting, beading and embedding. In this case, positive joins can be produced between substances of different kinds, such as plastics and metal parts.

In addition to welding, our ultrasonic technology is also used for punching and separation welding of plastics (Cut&Seal). Outstanding advantages of ultrasound are the careful process of edge sealing and visually appealing cut edges. The ultrasonic process also provides precise control of the welding and separation process, with good repeating accuracy and precision.


We are set tasks by all areas of the plastics processing industry. Our products are used principally in the automotive and packaging industries and industries such as:

  • Electronics, electrical engineering and telecommunications
    • Tightly sealing housings or displays
  • Household goods – “white goods”
    • Tightly sealing inspection windows and operation controls
    • Joining frame components
    • Welding fan impellers
  • Medical engineering
    • Tightly sealing analysis accessories or reaction chambers
  • Automotive engineering
    • Joining seatbelt buckles
    • Tightly sealing lamps and indicator lamp housings
    • Tightly sealing expansion tanks and valve bodies
  • Office supplies
    • Tightly sealing printer cartridge casings
    • Sealing transparent plastic folders and registers with visually appealing weld outlines
  • Sports equipment
    • Joining injection mouldings to elastic tapes
    • Attaching mesh fabric to injection mouldings

The structural design of the parts and the shape of the weld zone are very important, if the requirements of tightness and strength are to be met in the series production process. SONOTRONIC helps customers and potential customers by offering sound technical advice about designing components. In addition, we conduct fundamental application experiments to establish the welding parameters, achievable strength and to optimize the terms of reference.

Our scope of supply includes standard machines and handheld welding systems for manual operatinons, as well as components and systems for integration into automatic assembly lines. We are also market leaders in building customized special machines for automated production.