Definition - What does Epoxy Coating mean?
An epoxy coating is the use of epoxy compounds as coatings or paints. It is generally two parts, which are mixed prior to application and consist of an epoxy resin that is cross-linked with a coreactant or hardener.
Epoxy coatings are formulated based on the end product's performance requirements . When properly catalyzed and applied, epoxies produce a hard, chemical and solvent resistant finish. It is the specific selection and combination of the epoxy and hardener components that determine the final characteristics and suitability of the epoxy coating for a given environment.
Corrosionpedia explains Epoxy Coating
Epoxy coatings are created through the generation of a chemical reaction that uses an epoxide resin and polymine hardener. When these two chemicals are combined, the result is a process known as curing, which can take between several minutes to several hours and turns the liquid epoxy coating into an extremely strong and durable solid, often with strong mechanical properties, as well as resistance to high temperatures and chemicals. Because of these properties, these materials provide significant advantages over one-component coatings.
Epoxy coatings are formulated with optimum levels of a hardener for a given level of epoxy resin. The ratio differs from product to product. The use of an improper hardener may result in an undercatalyzed or overcatalyzed product. Many epoxy coatings require a specified induction time to fully compatibilize the epoxy resin and the hardener. Lower temperatures and/or high humidity generally require longer induction periods. Water-based primers require sufficient curing prior to top coating. Otherwise, discoloration, low gloss and possibly delamination result.
Epoxy coatings are popular because they provide a quick-drying, tough and protective coating. Unlike traditional heat cured powder coatings, epoxy coatings are quick and easy to apply, making them ideal for a number of applications. For example, they are typically used on concrete and steel to give resistance to water, alkali and acids. Metal cans and containers are often coated with epoxy to prevent rusting.
Epoxy resins are also used for floor application. Their low volatility and easy water clean up make them useful for factory cast iron, cast steel and cast aluminum applications, and reduces exposure and flammability issues associated with solvent borne coatings. They are usually used in industrial, automotive and marine applications. Furthermore, fusion bonded epoxy powder coatings are extensively used for corrosion protection of steel pipes and fittings used in the oil and gas industry, portable water transmission pipelines (steel) and reinforcing bars.