ABSTRACT
T HE growing demand for fine polymeric powders with high bulk density, good ftowability, narrow particle size distribution, and a particular shape requires continuous advances in powder technology and equipment. Commercially available polymeric powders are manufactured either by size reduction (comminution) or by solution process. Comminution is the process where materials are reduced in size by repetitive grinding via compression or impact. Mechanically ground powder typically has particles ranging from I 0 to 40 mesh (2,000 to 420 microns) in diameter; these particles usually have an irregular shape (depending on the grinding equipment used) and are suitable for dry powder coating applications and moldings. Finer powders ranging from 200 to 635 mesh (75 to 20 microns) in diameter are more suitable for solvent dispersions, bonding agents for textiles, and additives. Particle size is a very important characteristic that affects the choice of a powder for a given application. In general, the smaller the particle size, the higher the price of the powder.
