Powder Coatings that Fight Heat and Chemicals

The outstanding properties of polyfluorocarbons as the low coefficient of friction, chemical and thermal resistance, low wear etc. have led to the adaption of these resins as valuable coating materials. In this paper different coating techniques for PTFE and fluorinated ethylene-propylene copolymers are discussed. A new two stage two-polymers, fluidized bed coating technique is proposed as an alternative to the expensive coating with pure PTFE. The resulting coating is a bilayer composite consisting of a layer of a relatively inexpensive thermoplastic resin bonded to substrate followed by a layer of PTFE embedded in the thermoplastic resin. Properties of protective coatings made by means of proposed techniques are tabulated and evaluated in reference to conventional PTFE coatings.