Thermal-Spraying of Polymers and Polymer Blends

Abstract

Thermal-spraying of polymers can be traced back to the 1940s, when polyethylene (PE) was first produced by E.I. du Pont de Nemours & Company. Early work with flame-spraying guns was unsuccessful because the equipment, designed for spraying metals, produced a flame that was both too hot and too short to melt the PE without degradation. The technology has advanced considerably in the past 20 years. Flame-spray equipment and hardware accessories have been designed by numerous companies (PFS Thermoplastics, Alamo, Eutectic + Castolin, etc.) specifically for polymeric materials. The new equipment provides either a lower flame temperature or uses special cooling shrouds to cool the center of the flame, providing a longer residence time at a lower temperature. Many plastics can now be completely melted in-flight and allow heat-sensitive components to be coated with plastic.