Relationship between particle scale capillary forces and bulk unconfined yield strength

One of the main problems in industrial applications is the handling of fine cohesive materials. This cohesion can cause hang-ups in process equipment and stop or slow down processing. Conversely, just a small quantity of cohesion in a bulk powder can prevent particle size segregation. It is obvious that understanding cohesion from a fundamental point of view is useful in describing process flow behavior. Capillary force between particles is one source of cohesion between particles. This paper presents a theory that can be used to model the cohesive behavior of bulk materials based on capillary forces between particles.