Effect of Tensile Stresses on the Evolution of Post-Compaction Properties of Sodium Chloride Tablets and its Mixtures.

This study focuses on the effect of moisture on the strength of tablets of sodium chloride (NaCl) and its mixtures after compaction. We built on our prior work that proposed an explanation of the strengthening of NaCl tablets due to a dissolution-reprecipitation mechanism and the decrease in strength of NaCl-starch tablets due to the presence of residual stresses on NaCl-NaCl contacts in the mixture. Here, we offer experimental evidence that induced tensile stresses on NaCl slow down or negate (if large enough) the strengthening mechanism. Based on the idea of the negative role of tensile residual stresses in NaCl mixtures, we prove experimentally that NaCl-X mixtures can be optimized in terms of post-compaction strength, if the elastic properties of the second component in the mixture match that of NaCl.