Effect of Aluminum Flake Orientation on Coating Appearance

摘要

The orientation of platelet-like pigments in coatings is affected by the processing conditions resulting in appearance variations of the final product. A set of aluminum-flake pigmented coatings having different flake orientations was prepared using various spray conditions. The orientations of individual flakes were determined using laser scanning confocal microscopy and appearance properties of the coatings were determined from optical reflectance measurements. A Gaussian orientation distribution was then used as input to a ray scattering model to calculate the optical reflectance of these coatings. The flake orientation distributions and the measured optical reflectance as a function of scattering angle are presented and the latter is compared to the calculated reflectance.