Modeling emissivity of low-emissivity coating containing horizontally oriented metallic flake particles

•Emissivity formula of the coating considering binder absorption is established.•Edge effect of a metallic flake particle to infrared radiation is considered.•Factors that influence emissivity of the coating are investigated systematically.•Validity of the model is verified by comparison between experiment and simulation.

The scattering and absorption cross sections of horizontally oriented metallic flake particles are estimated by extended geometric optics that includes diffraction and edge effects. Emissivity of the coating containing those particles is calculated using Kubelka–Munk theory. The dependence of emissivity of the coating on the radius, thickness, content of metallic flake particles and coating thickness is discussed. Finally, theoretical results are compared with the experimental measurements with Al/acrylic resin coating system and the results show that simulation values are in good agreement with experimental ones.