Types of Powder Coat - Spectrum International

Types of Powder Coat

Spectrum is a fully approved and licensed applicator of the leading manufacturers of high-performance powder coatings as well as polyesters, epoxys and acrylics.

There are two different types of powder coat - thermoplastic and thermoset. Thermoplasic powders melt and flow when heat is applied but they continue to have the same chemical composition once they cool and solidify.

They are generally applied to a surface that has been preheated to a temperature significantly higher than the melting point of the powder. As a thermoplastic powder material is applied to the hot surface it will melt and "fusion bond" to the surface and then "flow out" into a strong, continuous film. As the film cools it develops its physical properties. Nylon powder coating materials are the most commonly used thermoplastic powders.

Thermoset powder coatings also melt when exposed to heat, but they then chemically cross-link within themselves or with other reactive components. The cured coating then has a different chemical structure than the basic resin. Thermosetting coatings are heat-stable and, unlike thermoplastic powders, will not soften back to liquid phase when re-heated.

Thermosetting powders are derived from four generic types of resins: epoxy, acrylic, polyester and fluoropolymer. From these resin types, several coating systems are derived. Resins used in thermosetting powders can be ground into fine particles necessary for spray application and a thin film finish. Most of the technological advancements in recent years have been with thermosetting powders.


AAMA 2603
To meet the AAMA 2603 specification, powder coatings are most often formulated with standard durable polyester binder. AAMA 2603 is typically an interior specification, such as ceiling panels and supports and interior windows. 2603 powders offer good resistance to abrasion, scratching and scuffing, but should be applied where color retention is not required.

AAMA 2604
AAMA 2604 is an "intermediate" specification. 2604 powder coatings are formulated with super durable or modified polyester resins. An ideal application for this paint would be balconies and railings where its toughness gives good resistance to wear. This finish will provide good color and gloss retention for approximately five years of exposure.

AAMA 2605
AAMA 2605 is the high-performance exterior specification. Depending on the manufacturer, a 2605 powder coat may or may not utilize a fluoropolymer resin (PVDF). These finishes are resistant to moisture, weathering, ozone and UV radiation. An application for this finish would include architectural projects that require long term cosmetic and functional protection.