Effect of Shape and Size of Aluminum Flake on Graininess Property ofMetallic Coatings

Metallic coatings are widely used in various industries due to their visually appealing appearance.These coatings produce diverse visual textures by altering the observation or illumination angles.Graininess is one of these texture characteristics which can be seen as a light/dark contrast patternunder diffuse illumination. This research investigates the impact of metallic flake shape and size ongraininess. We prepared ۲۴ samples in shades of silver, green, and black, with ۸ different flake sizesranging from ۸ to ۵۴ microns, including ۴ silver dollars and ۴ cornflake types. Graininess wasquantified using a BYK-mac-i gonio-spectrophotometer, and spectral reflectance and CIELABcolorimetric data were collected under diffuse lighting. The results indicated that increasing particlesize from ۸ to ۲۸ microns causes a sharp increase in graininess. A further increase causes slightchanges in the graininess. Additionally, silver dollar particles appear grainier than cornflake-shapedones of similar sizes. Moreover, the lightness of the absorption pigment in the coating correlates withgraininess—higher lightness of the absorption pigment leads to greater measured graininess.

کلیدواژه ها:

Metallic coatings ، graininess ، flake size ، silver dollar ، cornflake