We prepared a powder mixture composed of plate like particles (mica) and spherical particles (PMMA) by a conventional dry mixing and investigated to determine the effect of the particle size and the ratio of plate like particles to spherical particles on some dynamic behaviors of the powder bed.
Interparticle friction of the powder bed consisted of a mixture of large size mica and small size (less than 1μm) PMMA decreased remarkably at small fraction of PMMA. From a SEM observation of the mixture, the microspherical PMMA was found to adhere uniformly on the mica surface. By the addition of PMMA, since the type of adhesion between mica particles changed from a “plane-parallel surfaces” to a “sphere and half-space”, the attractive force between the particles seemed to be decreased. Also the mixtures prevented card-pack coagulation of the mica particles.
However, it was ascertained that the mixture was packed homogeneously in the compaction process because the dispersed mica behaves as primary particles.