Laser Welding of Polymer Foils with Gold Nanoparticles as Optical Absorber

摘要

Gold nanoparticles were used as absorber material for laser welding of transparent ethylene tetrafluoroethylene (ETFE) polymer foils. The gold nanoparticles were deposited by magnetron sputtering and covered with a thin plasma polymer film to stabilize their mechanical properties. After joining the coated foil with an uncoated ETFE foil, Laser irradiation was performed by a defocused continuous wave diode laser at a wavelength of 808 nm. During the laser irradiation, the gold nanoparticle change their size and shape by coalescence and melting and the welding seam becomes transparent. Particles size and shape were determined by transmission electron microscopy (TEM) and correlated with the optical spectra. Mechanical tensile tests have shown that the tensile strength of the laser welding seams are comparable to conventional welding seams made by thermal contact welding.