Abstract: This invention relates to modifying the surface of particles for improved dispersion characteristics in aqueous, solvent, resinous, polymeric, cementitious or the like application systems. In particular, this invention relates to a pigment or filler particle whose surface is coated with at least one electric charge modifying agent and at least one dispersion promoting agent, which has improved dispersibility, coloring, handling, and other processing properties in application systems. The electric charge modifying agent may be selected from the group of Mg, Ca, Ba, Sr, Ti, V, Zr, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Al. The dispersion promoting agent may be selected from the group of stearates, acetates, alkylphenols, cellulosics, waxes, lignins, polyacrylics, polyepoxies, polyurethanes, polyethylenes, polystyrenes and polypropylenes, and polymers having functional groups of alcohols, glycols, aldehydes, amides and carboxylic acids. Iron oxide is the preferred pigment particle.

Abstract: A simple, low-cost container filling machine includes a pulse pump for drawing high-density, high viscosity, thixotropic pigment from a shipping container, an accumulator for smoothing flow of the pigment, a non-adjustable and replaceable anti-drip dispensing tube, an adjustable optical level sensor, and electronic means for setting the optical sensor. A fixed platform for containers being filled includes anti-splash and aligment devices.