Drug Development Technologies
Extending Rheological Measurements Using Squeeze FlowMalvern Instruments
As samples with high-solids fractions can be prone to fracture, making shear rheological measurements can cause difficulties on a rotational rheometer causing sudden and sharp decreases in shear stress to be seen in the data.
An example of a concentrated suspension prone to such effects is toothpaste. These generally comprise an abrasive, a polymeric thickener, and a dispersant in an acqueous base together with flavourings and preservatives. Such highly-packed materials typically show fracture under rotational shear, which can be problematic when assessing performance under conditions relevant to the application.
In the case of toothpastes, it can be difficult to determine flow characteristics relevant to processing and it is often difficult to predict how the finished paste will flow out of the tube.
Download this free whitepaper to find out more about sample fracture and alternative ways to measure shear flow properties.