Laser Welding Design Guidelines

Download these guidelines.

Common Joint Designs

Laser welding uses a precise IR laser beam that is directed through a transmissive material and penetrated into an absorptive material. As with all plastic joining technologies, a properly designed weld joint is critical to achieving the desired weld strength and appearance.

General Guidelines

  • The transmissive part must be transparent/translucent to IR, but does not have to look transparent to the human eye.
  • The transmissive part should be approximately 3 mm thick or less for semi-crystalline materials and can be much thicker for amorphous materials as long as they are transparent.
  • If the transmissive part has glass filler, as the percentage increases, the maximum thickness decreases due to scattering of the laser energy.
  • Typically weld ribs are 2 mm wide, but narrower or wider is feasible and depends on customer requirements.
  • Typically plan for 0.2 – 0.4 mm interference (displacement) in the weld joint unless it is a simple lap joint or an inline lap joint that doesn’t allow for displacement.
  • Make gaps twice as tall as displacement depth to account for flash.

Lap Joint Designs

Simple Lap Joint

Sacrificial Rib Lap Joint

Inline Lap Joint

T Joint Designs

Simple T Joint

Sacrificial Rib T Joint

Lower Skirt T Joint

Upper Skirt T Joint

Upper Skirt Sacrificial Rib T Joint

Radial Welding Joint Design

Radial Welding Joint

  • Interference is required between the two components.
  • Typically plan for 0.1 – 0.4% of part diameter interference.
  • The angle of interference depends on overall part geometry, aesthetics, and strength. The angle should be between 45 and 85 degrees.

Discover the laser welding process

Have a question?

Please contact us with any questions.

Contact us.