Pulsed and continuous-wave laser paint removal on glass fiber-reinforced polymer composites (invited)

The light-gray erosion protection coating and anti-static finish coating on the surface of glass fiber-reinforced polymer composites were removed using a nanosecond laser with a wavelength of 1 064 nm employed in both pulsed and continuous-wave (CW) modes. The effect of the laser parameters at different laser modes on cleaning quality was investigated. SEM was used to observe micro morphology of material surface and cleaning products after processing. EDS and FTIR were used to detect the element content and chemical functional groups on the surface of materials before and after cleaning respectively. The temperature field during cleaning was analyzed by COMSOL Multiphysics. The results reveal that when removing the single anti-static coating, the pulsed laser can completely remove the top coating while just slightly harming the primer. When employing pulsed laser technology to remove the double paint, there is still a residual paint on the substrate's surface. The rainproof prime paint, resin and fiber layer of the substrate are also easily damaged. While the continuous laser can fully remove double paint and provide a clean surface. The pulsed laser removal process predominantly involves thermoelastic vibration effect, whereas the CW laser removal procedure is mostly thermal ablation. These results can serve as a guide for choosing the laser mode when removing paint from aeronautical composite surfaces.