Contact configuration and meniscus curvature for capillary adhesion in powders

Capillary adhesion has been pointed out to be an important mechanism contro lling the properties and behaviour of medium-particle-size dispersed materi al. A generalised method for calculation meniscus curvature radii of liquid bridge formed between powder particles as a result of water vapour condens ation has been given. The obtained relationships will be a basis for capill ary adhesion force calculations and for estimation of the effect of relativ e humidity of surrounding atmosphere on the forces. A complete analysis of the meniscus radii has been accomplished for all important contact configur ation systems existing in powders. On this basis hypotheses concerning the values and trends of adhesion forces in powders have been proposed.