Metallic Paint Colour Fine — Why Is Aluminium Flake Orientation Inconsistent?

Uniform flake dispersion in the mixing stage does not mean flakes will maintain consistent orientation in the film. Whether flakes achieve consistent alignment also depends on the film flow and cure process.

After spraying, the film undergoes a flow and cure stage. If flow time is too short or flow is non-uniform, flakes cannot orient fully — local orientation becomes chaotic, light reflection direction changes, and uneven brightness or poor metallic effect result.

During spraying: changes in spray distance, unstable gun atomisation, a single coat that is too thick or too thin, or inconsistent flash-off time all affect the wet film flow state and cause differences in flake orientation.

Metallic paint depends on more than the flake alone — the matching of resin, solvent, and additives is equally important. If system flow performance is insufficient, wetting is poor, or flake orientation capability is inadequate, the final metallic quality may be affected even when spray process is normal.

For complex-shaped workpieces — corners, curved areas, and edge zones — film flow velocity differs, and flake orientation is more likely to change. These zones are typically also where colour variation and flooding are most pronounced.

Metallic paint visual effect comes not from colour alone, but from how aluminium flakes reflect light. When flake orientation is consistent, the metallic effect is uniform; when orientation is chaotic, different angles reflect light differently — brightness variation, flooding, or cloud mottle appears.