Figure 1: HMC takes place in a fluid bed coater under controlled environmental conditions. The melting device (1) contains a heated tank for the molten coating materials, a stirrer and a heated tubing system to avoid solidification during transport of the molten mass into the fluid bed. The air layer gliding process (2) moves the particles into the spraying zone, creating a homogeneous temperature distribution as well as a spiral air circulation. The liquid is sprayed through a heated nozzle (3) and is atomized by compressed air into fine droplets ensuring a precise coating. The dust filter system (4) works continuously during the process. The filter bags, of which there are several, are cleaned by blowing air through the filters, thus removing any dust stuck to them. This approach reduces downtime to a minimum (Image courtesy of INNOJET Herbert Hüttlin).