ABSTRACT
I. INTRODUCTION Liquid detergent products span the entire rheology spectrum from low-viscosity Newtonian fluids to semisolid pastes, as demonstrated in Figure 4.1. Consumers can readily purchase the product form most in keeping with their preferences throughout the personal and household care product lines. For example, shampoos can be easily found that are low-viscosity Newtonian solutions, viscoelastic dispersions, or highly elastic gels. Similarly, laundry detergent products range in consistency and form from low-viscosity Newtonian liquids, to viscous pastes, to solid tablets. Developing these products to yield the desired shelf life and rheology stability is a complex task considering the number of components included in final commercial formulations.
