Plastics Joining

With vast materials expertise, broad polymer to polymer and to non-polymer joining capabilities, and years of application experience, EWI’s plastics joining group offers manufacturers a variety of resources to help improve current processes and develop new processes to lower costs, address environmental concerns, and improve quality.


Laser Plastic Welding

EWI has a history of innovation in plastics joining, including development of the through-transmission infrared welding process. We work with all plastics joining processes, from ultrasonic, laser, spin, vibration, thermal, and induction welding to adhesives and unique surface mechanical bonding techniques. Joining of plastic parts requires consideration of a wide range of factors including material selection, joint design, overall part geometry, environmental conditions, and cycle time. Our experts are intimately familiar with the advantages, disadvantages, and critical requirements of each unique process type and can provide objective recommendations on process and equipment selection. Our customers benefit from this expertise as they tackle challenges related to product design, prototyping, production launch, and failure analysis.

EWI has expertise in virtually all plastics joining technologies; however, our core strengths lie in ultrasonic welding, laser welding, spin welding, thermal welding, induction welding, and adhesive bonding.

Technical Expertise

  • Joining Processes
    • Adhesives
    • Ultrasonic welding / inserting / staking / swaging / cutting / sewing
    • Laser welding (through-transmission and keyhole)
    • Laser surface treatment
    • Infrared welding (through -transmission and standard)
    • Spin welding
    • Vibration welding
    • Hot plate welding
    • Thermal staking
    • Thermal sealing of films
    • Extrusion welding
    • Hot gas welding
    • Implant induction welding
    • Resistive implant welding
    • Radio frequency welding
  • Joining Support
    • Material weldability and selection
    • Joint design / design for assembly
    • Tooling design
    • Process optimization and parameter development
    • Troubleshooting
    • Cross-section / microtome analysis
    • CT scanning
    • Pull / peel / push / leak testing
    • Dynamic mechanical analysis
    • Fourier transform infrared spectroscopy
    • Differential scanning calorimetry
    • Microscopic analysis

Equipment and Lab Resources

  • Ultrasonic plastic welding equipment
    • 20 kHz servo press
    • 20 kHz pneumatic press
    • 20 kHz dual pneumatic press
    • 40 kHz pneumatic press
    • 15 kHz pneumatic press
    • 30 kHz servo press
    • 50 kHz probe & generator
  • Dual servo 3400 rpm spin welder
  • 940 μm laser diode with XY table
  • 3kW induction generator
  • Microtome
  • Polarized light microscope
  • Plastic weld testing and evaluation equipment
    • 250 lb capacity peel tester
    • Dynamic machine analysis (DMA)
    • Fourier transform infrared (FTIR)
    • Differential scanning calorimetry (DSC)
    • Computed tomography (CT) Scanner
    • Microtome
    • Polarized light microscope

EWI has helped many customers push the boundaries of their polymer joining processes. Here are some examples:

  • Developed ultrasonic technology to enable high speed package sealing. This solution can be easily integrated into most standard thermal sealing bag makers. Large scale demonstrations of high speed ultrasonic packaging equipment has achieved significant reduction in package material and associated cost and improved seals that provide enhanced shelf life. In addition, manufacturing data has documented improved quality that translates to reduced package and product waste. EWI has also recently completed a study on determining the correct ultrasonic tooling design for various films and can apply this method to any film being considered for ultrasonic joining, including bio-degradable and -compostable films.
  • Conducted an in-depth laser welding evaluation for American Axle & Manufacturing, Inc. (AAM) to determine the processing window for joining 15% glass-filled nylon components, identifying settings for multiple key process variables, verifying that joint strength and leak rates were within allowable ranges, and positioning AAM to implement laser welding in future applications.
  • Published a peer reviewed paper on the effect of joint design on ultrasonic welding of polybutylene terephthalate (PBT). This work involved modeling the heat generation rate in the polymer to predict the melting rate and optimizing weld parameters for a shear, 90-degree, 60-degree, and a new round energy director joint design. This research demonstrated that a longer lasting and less expensive to manufacture round energy director can be used effectively with servo motion control during ultrasonic welding.
  • Developed a method to bond a polymer film to a thin metal sheet without the use of adhesives. This method resulted in bond strength such that, when the polymer was peeled from the metal, the polymer film broke outside the weld and left material adhered to the metal.

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