Laser stripping of functional coatings on glass fiber reinforced plastic substrate

Glass fiber reinforced plastic (GFRP) with functional coatings is applied more and more in aircraft, thanks to its light weight and excellent mechanical properties. However, the outermost coating must be removed duo to discoloration, paint dropping, cracking, pits, or other fatigued phenomena after a certain amount of service time. The outermost torn coating on a GFRP material is successfully stripped with a nanosecond laser source. The influences of key laser parameters such as laser power, pulse overlap, and pulse width are studied. Thereafter, an optimized laser processing window is obtained and further validated with specified characterization methods. The repainting and adhesive bonding tests afterward indicate that a laser stripping process is superior to traditional sandpaper polishing because of the effects of surface roughening and microstructure interlocking. A case study further suggests that laser stripping outperforms sandpaper polishing because of its higher efficiency and better quality.