(660b) Optimizing the Design of a Compaction Simulator Using Discrete Element Method (DEM)

Preferential flow in both rotary and single station tablet presses is an important problem that can give rise to adverse effects on content and mass uniformity of active pharmaceutical ingredient (API) within the tablets. In this study a DEM model is developed to assess the powder flow in a lab-scale compaction simulator device. This device consists of a feeding hopper system, a single paddle wheel feed frame, and a die-filling region. The DEM model is used to identify a preferential flow pattern within the feeding hopper. Particle trajectories are studied to understand the underlying physics of the observed preferential flow patterns. To remedy this problem, various static insert designs are proposed, and their performances are computationally investigated. It will be shown that using an optimized static insert significantly reduces the volume of no-flow region within the hopper. Furthermore, it will prevent the formation of an inclined surface at the top of the powder bed, and therefore, mitigates the risk of free-surface rolling segregation. Finally, the performance of this design is computationally evaluated for powders with different levels of cohesivity.