In addition to the classic thermal connection processes (staking, ultrasonic welding, …), laser transmission welding is becoming increasingly important for joining plastics. This is a single-stage process, where the heating of the plastic and the joining process take place almost simultaneously. One element to be joined must have a high degree of transmission in the laser wavelength and the other must have a high degree of absorption. Prior to the welding process, the two components are positioned in the required end position and the joining pressure is applied until the required setting has been reached.