Segregation of a Binary Granular Mixture in a Feed Shoe of a Single Punch Press Using DEM

This work analyzes the segregation phenomena during the die filling of a binary granular mixture in the feed hopper of a tablet compression machine. These phenomena, which are caused by an alternative movement of the feed hopper, are investigated using DEM simulations and empirical tests. The optimal values of the model parameters were adjusted after comparing them to the results of compression tests conducted on a real machine. In order to reduce the computational cost in using a feed hopper with dimensions similar to those of a conventional hopper (fully 3D model), the width of the feed hopper was reduced by 60 % (thin sliced model) in the simulation and the experimental tests. Due to the characteristics of the ingredients used in this study, the most relevant parameters of the simulation were the method of filling the feed hopper, its geometry and the value of different friction coefficients. The main outcome of this study has been a model that permits reasonable simulation of the segregation phenomena that occur in the feed hopper of a tablet compression machine (‘single punch’ eccentric press).