The company says that until recently, there has not been any method available for such measurements outside of a few research institutes and universities. Now, however, these properties can be quickly, scientifically and reproducibly measured for the first time using its Thermo Electron Haake CaBER1 Capillary Break-up Extensional Rheometer.
For the cosmetic industry in particular, but also the food and pharmaceutical industries, the pumping, mixing and processing of diverse fluid streams and filling the final product is often a messy process, leads to losses and added costs for cleaning.
Rheology Solutions claims that the secret behind regulating the flow of liquids, and thus minimising waste during processing and packaging, is to gauge the liquid's viscosity - basically the degree to which the liquid resists flow under an applied force - in an effort to regulate it and exercise more control over the filling and process. An accurate estimate of this can allow processing and packaging to be adapted to minimise waste.
The company says that its Extensional Rheometer can provide information on the apparent or relative extensional viscosity, as well as directly measuring the time to break-up of liquid strands. With this knowledge it said that the surface tension of the liquid and actual extensional viscosity can be computed to be factored into the filling process.
A commonly occurring problem filling bottles with liquids is that unpredictably viscosity means that there is often spillage. This means that before labelling and final packaging, resulting spillage means that the bottles often have to be cleaned, lengthening the packaging process and causing, often unnecessary costs associated with both waste and the cleaning.
"The stringy behaviour of these fluids is related to a flow property known as extensional viscosity," a company spokesperson said. "Products with high extensional viscosity will tend to form threads or strings when poured, chewed or otherwise stretched. Although extensional viscosity may be related partly to viscoelastic properties, it can only be properly measured in extension, not by the traditional techniques of shear or dynamic rheometry."
With a clear knowledge of the liquids extensional viscosity, the filling process for the liquid can be adapted to make it more accurate - often this can be simply a case of adapting the filling speed to suit the bottling application.
The company says that until recently, there has not been any method available for these measurements outside of a few research institutes and universities. Now, however, these properties can be quickly, scientifically and reproducibly measured for the first time using the Thermo Electron Haake CaBER1 Capillary Break-up Extensional Rheometer.