Mechanical characterization of spray-dried granules by compression and stress-relaxation technique - Analysis of relaxation behavior

The stress relaxation behavior of granules has been evaluated by dividing i t into three parts: plasticity, viscosity and elasticity. It is shown that addition of binder or increasing dispersant concentration reduces the granu le plasticity and increases the granule viscosity. It is also shown that th e transient behavior of plasticity and viscosity is well correlated to the breaking and/or deforming behavior of granules, as observed by optical micr oscopy. It is expected that a homogeneous green body may be obtained using viscous granules.