Direct measurement of the forces required to disrupt and remove fouling deposits

In cleaning, the force required to disrupt the deposit and remove it from the surface tends to be inferred from flow data, rather than being known directly. A novel micromanipulation technique has been developed to measure directly the adhesive strength of food fouling deposits on a stainless steel surface. A T-shaped stainless steel probe pulls fouling deposits away from the surface to which they are attached. The apparent adhesive strength between the fouling deposits and the substrate can be measured as the work required to remove the deposits per unit area from the substrate. Tomato pastes and whey proteins have been used as model deposits. The influences of process variables and different cleaning strategies can be identified, and the differences in cohesive and adhesive behaviour of the materials identified. The results can be compared to larger-scale cleaning processes.