Colloid, Dispersion and Roller Mills

Dispersion, colloid and roller mills are used to reduce solid products to a desired particle or aggregate size in dry or slurry forms. Colloid mills use discs or rotors that spin at very high speeds in a liquid media. The shearing action from the high speeds and small gap between the rotor and stator or chamber provides emulsification or dispersion. Often, the rotors have a serrated outer surface. Some dispersion mills with larger gaps also use fine beads within the liquid to enhance dispersion. Roller mills or three-roll (3-roll) mills disperse and refine a fine powder or pigment into a liquid by passing the paste between a series of rolls rotating at different speeds. Three roll, colloid and other dispersion mills are used commonly in paint, resin and adhesive applications.