Behaviour of soft granules under compression: Effect of reactive and non-reactive nature of the binder on granule properties

✍ Scribed by Sujitkumar Hibare; Ramlingam Sivanathan; Suresh Nadakatti

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 979 KB
• Volume: 210
• Category: Article
• ISSN: 0032-5910
• DOI: 10.1016/j.powtec.2011.03.024

✦ Synopsis

Granulation is a process where primary powder particles are made to adhere to form multi-particle entities called granules and this is achieved by using a binder. The binders can be broadly classified into two categories viz. reactive (reacts with base powder) and non-reactive (does not react with the base powder). The effect of various parameters related to binder liquid (binder viscosity, addition rate, distribution over the bed etc.) on the mechanism of granulation and physical/mechanical properties of granules is well studied. However, comparison of physical and mechanical properties of granules made via reactive and non-reactive binder using the same base primary particles has not been reported. In this paper, granulation of sodium carbonate primary particles under reactive and non reactive conditions was studied. The mechanical properties of sodium carbonate granules were characterized using single granule compression measurements. The average single granule apparent strength of reactive granules was higher compared to non-reactive granules. It was observed that granules formed using non reactive binder were brittle and showed multiple breakages. However granules made using reactive binder showed single breakage followed by significant plastic flow. In addition, bulk granule compression measurements were also carried out. Known models of Heckel, Kawakita and Ludde, and Adams et al. (developed mainly for pharmaceutical and metal powders) were used to predict mechanical properties of soft detergent granules. The bulk granule compression measurements also showed that reactive granules have higher strength compared to non-reactive granules. However, the absolute values of granule strength obtained from the empirical models were lower than the granule strength obtained from single granule compression measurements.