Discrete element modeling of the mechanical response of pigment containing coating layers under compression

In this study, a particle flow model was employed to study the dynamic behavior of a thin porous coating layer containing mineral pigments under compression. The model for coating layer consisted of a packed box filled with randomly arranged spherical pigments and latex particles that were generated according to some desired size distributions. Effects of coating porosity, pigment size and size distribution, latex stiffness, and particle-particle micro-friction on the mechanical properties of the coating layer were investigated. It was observed that the pigment size distribution and the initial porosity of the coating layer had a significant effect on the elastic modulus of the coating layer. In addition, simulation results showed that pigments with a narrow size distribution resulted in stiffer coating structures than pigments with a broad size distribution. Furthermore, it was shown that a stiff coating structure could also be formed by using stiff latex particles as binders. Simulation results also demonstrated the significance of particle-particle micro-friction on the compressive response of the coating layer.