Effect of Sandpaper Meshes on the Performance of Tilia Sp. Self-Repairing Coatings

This study aimed to investigate the impact of different sandpaper sanding meshes on the mechanical and optical properties of microencapsulated Tilia sp. film. An orthogonal experiment revealed that sanding between primers had the most significant effect. Furthermore, an independent experiment implied that increasing the mesh size resulted in decreased surface roughness and decreased color difference, elongation at break, and gloss after liquid resistance. In the aging test, the color difference of the paint film increased with the aging time, and the gloss tended to stabilize. Additionally, the anti-aging gloss of 240 mesh sandpaper used between primers remained relatively stable. The paint film sanded with 240 mesh sandpaper between primers displayed small and regular cracks after temperature and UV aging. Overall, the paint film demonstrated good comprehensive performance when sanded with 240 mesh between primers, 240 mesh between primer/topcoat, and 1000 mesh for topcoat. Self-repairing microcapsules showed better repair efficacy on the coating. This study provides a technical reference for the development of self-repairing coatings.