Numerical and experimental analysis of sand blasting on polymeric substrates

In view of the recent interest in modifying the surface functionality and esthetics of polymeric materials by sand blasting treatment, a numerical model was developed as a tool to predict the evolution of surface morphology as a function of blasting parameters. The wide range of shot size and shape variations, typical of blasting media, were parametrized based on microscopical observations. Thus, the developed numerical model accounts for the media inhomogeneity and also implements randomness in both the sequence and position of the multiple impacts. To make the model as realistic as possible, the velocity of individual shots was calculated based on their interaction with the airflow. Systematic experiments were performed using Polycarbonate (PC) as the substrate material and Alumina as the blasting media. A comparison of the experimental and numerical results demonstrated the ability of the developed model to successfully predict the surface roughness generated by sand blasting, as the shot arrangement and distribution were varied. This model establishes a potential basis for future studies regarding the performance of the sand blasted surfaces such as wettability using numerical approaches.