Direct measurement of particle–particle interaction using micro particle interaction analyzer (MPIA)

Direct particle–particle contact force measurement was successfully conducted for realistic parameter determination to support discrete element method (DEM) simulation by using a newly developed force measurement of micro particle interaction analyzer (MPIA). In this system particle-to-particle distance and deformation can be controlled by nanometer accuracy. The system can be used for measuring not only short-distance deformation but also long-distance deformation that was validated by both elastic contact and liquid bridge interaction including rupture distance, respectively. Then, the system was applied to obtain plastic normal deformation characteristics such as coefficients of restitution of the spherical granules at low loading force less than 0.5 mN. Granules were prepared from two-stage pressure swing granulation (PSG) technique in a fluidized bed.