Anton Paar has published an application note on the use of modern rheometers in combination with absolute measuring systems in the quality management of thickeners.
Viscosity-increasing ingredients such as xanthan gum are widely used in complex products such as pharmaceuticals, creams, health-care products, food ingredients and dietary supplements. Their use is regulated by standards, such as the Pharmacopoeia (e.g. United States Pharmacopoeia and the European Pharmacopoeia). Although the applications of these ingredients are diverse, absolute and trustworthy rheological data are constantly required for the production and quality management of such products.
Measurements using a relative measuring system, such as a spindle, can only provide relative viscosity values because of the undefined gap dimension and thus an undefined shear field. Such results are only comparable when using the same measuring system at the same measuring height and constant temperature and, thus, can only give information about relative viscosity values.
The report gives an overview of conventional methods, before detailing the benefits of using a modern rheometer and absolute geometries in rotation.
