288596 Complex Fluid Flows in Chemical Product Development
Many Chemical Products that we use everyday are prepared, sold or used as highly complex formulations which may contain liquids and dissolved or dispersed solids. These are typically a complex medley of flow modifiers, surface active agents, fillers, polymers, colorants and solvents. This concoction of materials leads to a complex flow behavior under various conditions, many of which are not well understood. Some examples of these products include paints & coatings, adhesives, slurries and pastes, thermosetting or film forming polymers and consumer products such as laundry detergents, skin lotions and shampoos. Flow behavior can be a key determining factor of the product characteristics such as particle size and distribution in dispersed polymer systems or other emulsion products. Flow properties can also be critical in the application performance and consumer perceptions of products such as paints, lotions, etc.
In this talk, we will use practical examples of these ubiquitous products to describe some of these complex flows. We will describe how rheological characterization of these systems is fraught with complications of high normal stresses, high inertia and slip behavior while surface flow behavior characterization is confounded by multi-component dynamic wetting, time-dependent behavior and fluid instabilities. We will describe some of our efforts in using a scientific and statistical approach in understanding this behavior as well as strategies used to modify flow properties to meet those needs. We will also endeavor to outline a few of the open-ended flow problems that remain important but not well understood.