Measurements of micro particle rotation by applying marking points using additive manufacturing tools

The rotation can significantly influence the impact behavior of fine particles. By performing collision experiments with marked particles, the rotation depended particle- wall or particle–particle interactions, like rebound angle and energy dissipation, can be investigated. This method is widely used for particles with a diameter >1 mm. A sufficient method to mark micro particles has not been presented yet. Therefore, a validation method for collision theories and contact models for the Discrete Element Method for micro particles with rotation is missing. This study introduces two different methods, named pin contact and micro stamp method, to apply marker dots to spherical particles smaller 1000 µm using tools produced by two different additive manufacturing techniques. Free fall tests of marked particle on an inclined wall were performed to proof these methods regarding their handling and quality of the imprinted tracer dots.