The Developed Trends in Powder Coatings Technology

Abstract

Today, reducing the use of volatile organic compounds is one of the most important issues for environmental protection. Since the 1950s, powder coatings have been widely considered in the surface coating field, especially pipelines, households, and office appliances, due to their environmental friendliness and excellent performance. These types of coatings are solid and they are applied to the surface in the form of powder using different methods such as electrostatic or fluidized bed and then they are cured by heat. In this study, a brief history of the development of powder coatings is described, and it is continued by full report on the types of powder coatings, their production methods and processes, and the research process, emphasizing the type and characteristics of the resins used in this industry. Considering the importance of powder resins in the formulation of powder coatings, the performance of various thermoplastic and thermosetting resins used in these powder coating systems, including polypropylene, polyethylene, poly(vinyl chloride), fluoropolyethylene, nylon, epoxy, polyester, polyurethane, acrylic, cellulose acetate butyrate, and recycled resins are compared. In addition, the method of application and film formation in electrostatic coatings and the factors affecting them are investigated comprehensively. Furthermore, some of the challenges and problems of this giant industry will be introduced in order to improve its quality and curing methods for to expand the applications. Finally, new technical approaches, aiming to save energy and produce more biocompatible powdered products, using infrared curing technology, curing by ultraviolet radiation, or the ability to coat sensitive-temperature surfaces by powder coating are described.

Keywords

• powder coatings
• thermoset and thermoplastic resins
• electrostatic spray
• polyester
• epoxy