What is the principle of plastic laser transmission welding?

【summary】

Laser transmission welding is a process where the laser beam penetrates the upper transparent component and is subsequently absorbed by the lower laser-absorbing component. When the laser energy is absorbed by the dye or additive particles, it is converted into heat energy. The surface of the absorbing component melts and the heat is transferred to the upper transmissive component by heat conduction. Before welding begins, the two components are in contact with each other under the action of external forces. During welding, the components are locally heated, which causes thermal expansion of the material and generates internal welding pressure. Under the combined action of internal and external welding pressure, the two components are firmly welded together. The relative movement of the laser beam and the welding components forms the weld.