6. Cohesive forces in wet granules

Agglomeration is only possible when the forces of interparticle adhesion become greater than those of disintegration, exerted by the external environment. In addition, the mechanical strength of the granules plays a decisive role in the growth kinetics and final particle size of the resulting product. This strength naturally depends on the interparticle bonding forces present within the granules. In the case of wet granulation, the predominant forces are those of the so-called mobile liquid bridges. However, the strength of a particle assembly linked by liquid bridges depends not only on the bond strength of an isolated link, but also on the amount of liquid present in the interstitial space of the particle cluster. In practice, depending on the degree of saturation S of the particle cluster, defined as the volume fraction of the interstitial space occupied by the liquid, four states of...