Correlation between bulk stresses and interparticle contact forces in finepowders - art. no. 031301

We present measurements of the tensile strength as a function of the consol idation stress for a set of fine Cohesive powders (xerographic toners) of 1 2.7 mum particle size and with a range of concentration of submicron fumed silica as flow control additive. This additive is well known for its abilit y to control interparticle adhesion force. Parallel measurements using an a tomic force microscope have been carried out on the adhesion force between two individual grains as a function of a controlled previous load force. Th e effect of the additive on the tensile strength and adhesion force is anal yzed. We have found a good correlation between bulk stresses and adhesion f orces between individual particles. This correlation is compatible with the existence of a subnetwork of force chains.