Evaluation of solvent-based and UV-curing inkjet inks on the adhesion and printing quality of different aircraft surfaces coating

Abstract

This work presents a study of digital inkjet printing technology for aerospace industry using different coatings on aluminum surfaces. The objective of this work is to understand the effect of some process parameters on digital inkjet printing technology in the aircraft industry for printing complex images, logos and other visual effects directly on the fuselage of aircraft with high quality, in order to replace conventional and manual aircraft painting processes. The consequent effects of the different coated surfaces on the properties of the printed images (e.g., adhesion, UV resistance, visual appearance and optical properties) were evaluated in order to understand how the coated surfaces affect these properties. For that purpose, solvent-based and UV-curing inkjet inks for industrial printing applications were used in the colors cyan, magenta, yellow and black on coated aerospace surfaces. The results show that the inkjet technology requires a white background substrate to match the conventional colors and there is an adhesion issue on conventional top coating used as a base for direct inkjet printing. The results reported here provide good evidence that the traditional aerospace surface used should be adjusted to improve the final print quality and paint film adhesion. The viscosity of UV-A inkjet ink is 2.1 times higher than UV-B ink and 2.4 times higher than solvent-based inkjet ink. The use of a new primer/top coating with clear coat is the optimal condition for maximizing the printed image properties, adhesion, UV degradation, low color variation (∆E*ab < 15) and improve the gloss effect (≥90GU). Although there are some challenges regarding this technology and these results create an effective strategy for the development of digital inkjet printing on aerospace surfaces with excellent final print quality.