Diode Laser Welding of Polyethylene

A high-power diode laser (HPDL) was used to weld high-density polyethylene (HDPE) sheets. Laser-welded joints were fabricated with different values of laser power and scan speed. Hot-tool welding was also employed to fabricate joints to make a comparison between this consolidated technology and HPDL welding. Initially, laser heating tests were carried out to study the laser–material interaction. Furthermore, welding tests were carried out and tensile mechanical tests were performed to characterize joints and sound specimens. A similar material behavior was recognized for all the specimens. While the laser process resulted in lower strength and ductility, in comparison to the tool-welding process, the aesthetics of the laser-welded joints were remarkable. The best values of the process parameters were individuated for the laser welding and were used to fabricate a closed structure having sharp edges. The same geometry cannot be obtained by any other welding technology.