Image processing for detecting complete two dimensional properties' distribution of granules produced in twin screw granulation

Abstract

In this study, an image processing technique is implemented to measure complete two-dimensional particle size and liquid content distribution (2D-distribution) of the granules produced in twin screw granulation (TSG). The effects of liquid binder viscosity and liquid to solid ratio (L/S) on the 2D-distribution, and the residence time distribution were studied. The effect of screw configuration on granule formation at different conditions was also investigated, were the mean residence time distribution (MRTD) in conveying elements decreases with the increase of L/S ratio and viscosity. While in kneading elements the MRTD decreases with the increase of L/S and increases with the increase of viscosity. The mean liquid saturation level of the granule is exponentially related to its size. As well, the increase in binder viscosity and L/S ratio leads to more uneven/bi-model particle size distribution (PSD) in the conveying elements, while kneading elements change the initial bi-model PSDs into more homogenous mono-model like distributions.

Keywords: Complete 2D distributions; Image processing; Liquid content distribution; Particle size distribution; Residence time distribution; Twin-screw granulation.