For laser welding, the two plastic components must lie flat on each other at the weld seam. The laser beam must be able to pass through the upper, laser-transparent part to the weld seam. It must not be shaded, deflected too much, attenuated or defocused.
If collapse should be measured during welding in the quasi-simultaneous or simultaneous process type, a rib must be melted down. This rib is best in the lower laser-absorbing part and rectangular, so that in the weld seam itself two surfaces lie again flat on each other. A triangular or trapezoidal rib, as usual for ultrasonic or vibration welding, is not useful for laser welding.
In order to catch the plastic melt pushed out during melting down the rib, an empty space can be provided next to the rib. For example by a corresponding groove in the upper part.
For circumferential welding, a press fit must be designed between the two cylindrical parts, as external clamping is not possible. The inner part must be pressed into the outer part with an axial force.