The visco-elastic characteristics of compacts of Starch 1500, Emcompress and paracetamol powders were studied at different loading rates and values of packing fraction. Creep experiments were performed using a tensile tester fitted with a compression cage, operated at selected platten rates to achieve specific mean rates of load application to constant load. Derived measurements included the instantaneous and retarded elastic compliance, the retardation of elastic compliance and the apparent viscosity. An improved method is proposed to calculate the ratio of elastic to plastic deformation for particulate solids during compaction, and to characterize their rheological behaviour. The time at which total creep compliance is equal to the equilibrium value of elastic compliance at infinite time is shown to be a possible parameter for quantifying the retardation of elastic compliance. © 1992.
Malamataris, S., Rees, J. E., & Hart, J. P. (1992). Influence of loading rate and packing fraction on visco-elastic behaviour of powder compacts. Powder Technology, 69(3), 231–238. https://doi.org/10.1016/0032-5910(92)80014-N