Precise energy control
Transmission welding processes join plastic by melting the interface between two materials. A laser beam typically passes through one transparent thermoplastic material that is clamped against another. The second thermoplastic may be doped with an optically-absorbent material such as carbon black to help absorb the laser light at the interface. The result of the process is a melting of the materials at the interface which forms a strong and permanent bond between the two. Transmission welding is popular when fast, permanent, and low mechanical stress joining of parts is required without the use of adhesives or other mechanical fixing devices such as screws and clips.