Abstract
Mechanical properties of spray-dried granules have been characterized in compression by repeatedly applying and stopping stress, In order to shorten the experimental time and obtain optimal conditions for reliably evaluating the relaxation behavior, we discussed the influence of compression rate, compression number, relaxation time and initial height of the granule bed, respectively. It was found that the stress relaxation of granules increased with increasing compression rate. It was also demonstrated that the stress relaxation was almost independent of the initial height of the granule bed, Furthermore on the one time compression and stress relaxation test, the results were found to be in good agreement with those obtained from the multiple compression and stress relaxation test. These results show that the experimental time can be shortened from a few hours to about ten minutes.
