What is extensional viscosity?
In real processes, flow profiles are likely to contain both shear viscosity and extensional viscosity components. For complex fluids, the material properties in extension can be significantly different to the material properties in shear deformation. The importance of assessing extensional flow properties is increasingly being recognized. For instance, two materials may give processing differences despite showing similar shear viscosity data. Measurement of extensional viscosity can be the key to highlighting the differences between the samples.
