Growth mechanisms in melt agglomeration with a low viscosity binder.

Lactose monohydrate was melt agglomerated in an 8-l high shear mixer using stearic acid as meltable binder. The impeller speed was varied at six levels, and the temperature of the heating jacket was varied at three levels. The agglomerate growth mechanisms were found to be different from those observed in previous melt agglomeration experiments. This is attributed to the low viscosity of the molten stearic acid. A higher impeller speed and a higher jacket temperature resulted in an agglomerate growth that was markedly affected by comminution and accordingly gave rise to agglomerates of a wider size distribution and a higher porosity. A lower impeller speed and a lower jacket temperature resulted in smoother and more spherical agglomerates.