Processing of non-Newtonian structured liquids with evolving rheology.

Within the Unilever Beauty and Personal Care (BPC) portfolio, products with a wide range of rheological properties are found defined by their microstructure including lamellar-structured liquids and high-solids content pastes, where comparatively limited research is dedicated to these systems. The proposed research project aims to gain better understanding of the processing challenges and of these two classes of fluids.
The manufacture of BPC products is achieved through the sequential addition of raw materials in defined orders, rates of addition and temperature profiles. Thus, there are two attributes which vary throughout the manufacturing process: (1) increasing fluid level and (2) variations in rheological properties for intermediate stages. These two attributes will impact achievable mixing intensity and efficiency, as well as flow characteristics within the vessel, affecting product quality, energy requirements and overall process optimisation.
The proposed project aims to explore these effects for both lamellar-structured liquids and high-solids content pastes, through use of dynamic torque measurements, the development of power draw expressions and flow characterisation techniques. Additionally, the project will explore the CFD space to identify an approach that would allow tracking the evolution of the vessel level and product rheology throughout the process, using experimental results for validation.