Determination of segregation tendency of granules using surface imaging

In this study, powder surface imaging was utilized in evaluation of particle size-related segregation behavior of granules during vibration and tableting processes. Altogether, eight granule batches were manufactured using a fluidized bed granulator. The particle size distribution of each batch was measured with sieve and image analysis. Segregation tendency of the batches was studied by a vibrational measurement setup. In addition, segregation during tableting was studied by taking samples during the tableting process. Image analysis was utilized to analyze the segregation in both cases. Roughness parameters (Ra) were calculated from images taken during simulation of segregation. In addition, weight variation of tablets was calculated. Finally, principal component analysis was used to visualize the effect of specific particle size fractions on segregation tendency of granules. According to the results, a broad particle size distribution and large particle size can inflict problems during tableting. Surface imaging was an efficient method to monitor the segregation tendency of granules during vibration and tableting. In addition, the segregation tendency of a granular material can be directly linked to weight variation of tablets during tableting and thus be used in a predictive manner.