Extensional rheology in food processing
[ 1 ] Instytut Technologii i Inżynierii Chemicznej, Wydział Technologii Chemicznej, Politechnika Poznańska | [ P ] pracownik
2023
rozdział w monografii naukowej
angielski
- extensional viscosity
- Trouton ratio
- filament thinning
- polymer solutions
- emulsions
EN Many kinds of flows are present in industrial processes in which extensional and shear flows are among important ones. Measurements of extensional viscosity ηE of liquid foods are important in structural characterization, process and quality control of products and process modelling and design. These measurements are incomparably more difficult than for the shear viscosity, because of variation of sample dimensions in time when sample is extended at a constant strain rate. This chapter will discuss the methods for measuring the extensional viscosity of fluids with low and high viscosities. Measurements of extensional viscosity are made not only with commercial apparatus but also with special custom constructed devices. Measurements of ηE of fluids having a viscosity lower than 1 Pa∙s are particularly troublesome. In addition, typical results of measurements of polymer solutions, emulsions and other fluids will be presented, as well as the theoretical basis related to issue of extensional viscosity.
13.09.2022
143 - 180