The commonly used laser welding form is called laser penetration welding. It is firstly to force the two plastic parts to be welded to be together through pressure and then locate a laser beam in short wave infrared region onto the position to be welded. The laser beam, after going through the upper-layer transparent material, will be absorbed by the lower layer. The laser energy, after being absorbed, will be transformed into heat energy. Since two layers of materials are forced together, the heat energy will conduct to transparent layer from absorbing layer, which would make the two layers of materials melt and connected.  At the same time, the internal pressure occurs because of the material’s thermal expansion. So the joint effort of the internal and external pressure can make sure that the two parts are firmly welded. For the product whose lower-layer material does not absorb laser, absorbent needs to be added to the lower layer.

Laser Plastic Welding Types

Clear Material Laser Welding