Fiber-optic semiconductor laser transmission welding system for thermoplastics

A transmission welding system with an optical fiber laser was established to realize the seamless welding of thermoplastics. The structure, laser source, beam collimation and focusing for the welding system were studied. The method of laser transmission welding was discussed according to the characteristics of plastic welding. Then the laser transmission welding system was designed by using the fiber laser as a source. By considering the divergence of the fiber laser source, the light beam collimation and focusing system was designed. The welding experiment of polypropylene specimen was carried out by using the designed fiber laser transmission welding system, and the tensile test of a welding specimen was performed. The results show that the welding strength of specimen is 379 N by the semiconductor laser transmission welding system, while the laser power is 40 W, the welding speed is 50 mm/s, and the content of carbon black is 0.1%. It satisfies the system requirements of practical applications. © 2015, Chinese Academy of Sciences. All right reserved.