For more than 50 years, powder coating has been established as a process in which technology and automation play key roles. The process has resulted in an industry that focuses on enhancing the surface properties of usually metal substrates. Lacking solvents, powder coating has little negative impact on the environment – one of its current appealing characteristics. Over the years, technology has produced variations of coatings; however, the division of types is frim. There are thermoplastic and thermoset powder coatings. Nylon is in the former category; polyester powder coating is a member of the latter.
Thermoset Powder Coatings: Basic Characteristics
Thermoset materials are the most common and known type of powder costing in use. They are often described as thin but hard. They differentiate from thermoplastics in a number of ways including such characteristics as crosslinking, rigidity and high hardness. After curing, unlike thermoplastics, thermosets remain stable. Even after heating, they cannot return into a liquid, flowing state.
These factors make the coating durable and resistant to abrasion and wear and tear. The preference by many industries for thermoset powder coatings essentially lies on their ability to look good while remaining strong and tough. In other words, thermosets are both decorative and durable. The extent they fall into either or both categories will depend upon the type of material chosen for the process. Industries can elect to choose from one of the four major categories of thermoset coatings including polyester powder coating.
The Four Classes of Thermoset Powder Coatings
Several classes of thermoset powder coatings are available for commercial and industrial use. Four major classes dominate. These are:
* Acrylic: Hardness, high resistance to stains as well as high gloss and color retention make this class of thermosets a common finishing process for the automotive industry.
* Epoxy: This powder coating comprises the largest and oldest class of thermoset powder coatings. Its characteristics include toughness, resistance to corrosion and chemicals and adhesion. It has good mechanical properties as well.
* Hybrids or Epoxy-Polyesters: These are known for their ease of application, high UV resistance and excellent color retention
* Polyester: Globally, polyester accounts for approximately 36% of all powder coating production. In the United States, this strong, tough, flexible, high performance coating has immense popularity.
Others divisions do not note hybrids but mention specifics such as fluoropolymers.
Polyester Powder Coating
Polyester is a popular choice for thermoset powder coatings. In the United States, it comprises the majority of the market. Its mechanical and aesthetic properties will always ensure that a polyester powder coating will continue to be prevalent and an integral part of effective industrial applications for years to come.
