Publication at Faculty of Pharmacy in Hradec Králové |
2019
Abstract
We performed test of consistency by penetrometry, rotational, oscillation and creep tests, and squeeze and tack tests of model samples to introduce methods suitable for characterization and comparison of semisolids in practice. Value of yield stress, generally considered to be appropriate feature of semisolids, is significantly influenced by the method of testing and the way of evaluation.
The hysteresis loops of model semisolids revealed incomplete thixotropy, therefore three-step thixotropy test was employed. Semisolids showed nonlinear response in the creep phase of tests and partial recovery of structure by storing energy in the recovery phase.
Squeeze and tack tests seem to be convenient ways for comparison of semisolids.