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Laser plastic welding - Contour welding

  • Laser plastic welding

    Laser plastic welding

  • Laser-Kunststoffschweißen - Konturschweißen

    Laser plastic welding - Contour welding

    Laser plastic welding - Contour welding

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Most important requirements for laser welding of plastics:

  1. The two components must be thermoplastic and chemically equal or very similar, otherwise the adhesion is merely based on indenting of the components - Table for possible material combinations
  2. The transparent material can also be milky (glass fiber reinforced). The scattering of the laser light does not make the welding process impossible.
  3. The transparent material can also contain special pigments, which cause a coloured or black effect, but which are transparent to the laser.
  4. Reliable and reproducible results are only produced with exact temperature control with LASCON®

Advantages:

  • No waiting times as with adhesives
  • No dosing problems as with adhesives
  • Exact process control with on-line monitoring
  • Short processing times – high production cycle

In laser transmission welding, a transparent cover material is pressed onto an absorbent base plate. The laser beam penetrates the transparent material and brings the absorbing material into the melt. The melt expands slightly and wets the transparent cover material. The laser head is guided along the contour with a robot and produces a uniform weld.

  • Typical welding speed: 10-30mm / s
  • Typical process temperature: 180 ° C - 240 ° C
  • Accuracy of temperature control during welding process: + - 2 ° C
  • Gas and watertight sealing of electronic housings
  • Welding of membranes in medical technology
  • Welding of filter housings in wastewater technology
  • Welding of lamp housings in the automotive industry

Simultaneous welding

  • Laser beam path through galvo scan head

    Laser beam path through galvo scan head

  • Mounting of LH501 laser processing head to a galvo scan head

    Mounting of LH501 laser processing head to a galvo scan head

  • Laser processing head LH501 with camera and pyrometer mounted to a scan head

    Laser processing head LH501 with camera and pyrometer mounted to a scan head

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The goal of simultaneous welding is to weld the whole contour with one laser shot instead of having a robot traverse along the entire contour. Various processes are available for this:

  1. In simple cases, the contour can be generated using laser beam shaping (for example ring-shaped optics)
  2. Creating a mask, which is illuminated by a laser
  3. The laser beam is scanned by a galvo optic mirror along the welding seem very fast and high frequently, so that the whole seam simultaniously starts to melt.
  • Scan fields up to diameter 130mm
  • Working distance typically 100mm to 200mm
  • Scanning frequencies up to 50 Hz
  • Temperature control of the welding seam by pyrometer through the scanning head

Fast laser plastic welding with high throughput