Process Optimization for Dual Laser Beam Joining for Dissimilar Plastics

A dual laser beam joining process is introduced for joining dissimilar plastics. A customized laser head was built, and two different diode lasers with central wavelengths of 980 and 1940 nm were simultaneously applied to obtain PMMA/PC-1 and PC-2/ABS joints. Various experimental conditions were employed for the dual laser beam joining, which were performed at different laser powers for the 1940 nm laser beam and a fixed laser power for the 980 nm laser beam. The tensile shear force of the PMMA/PC-1 and PC-2/ABS joints was measured, and compared with those using the 980 nm single laser beam joining process. For both joints, a decrease in tensile shear force was observed when the laser power of the 1940 nm laser beam increased. Only the dual laser beam joining using the 1940 nm laser beam at the smallest laser power showed relatively higher tensile shear force than those of the 980 nm single laser beam joining. The transmission values of the PMMA and PC-2 at the wavelength of 980 nm were measured with different powers of 1940 nm laser beam, and a correlation between the joining properties and transmission values was found.