4 Types of Powder Coating

March 31, 2021

What are the different types of powder coating?

  1. Polyester
  2. Super durable polyester
  3. Epoxy
  4. Urethane

Even a versatile alloy such as aluminum isn’t invulnerable to damage. This is why aluminum and other types of metals need to be coated with a durable film layer for added protection — powder coating. Powder coating types can vary, but they’re usually made out of synthetic substances called polymer resins or resin systems.

As the name suggests, powder coating comes in a pulverised form of coating that is electrostatically spray-deposited onto the surface of the metal/alloy. While the process is similar to spray painting, the raw materials and method of application differ between the two. Powder coating is also considerably more cost-effective and durable due to its composition — resin, additives, pigments, extenders, curing agents, and more.

Although powder coatings are made out of polymers, the types can be further subcategorized into the following: polyester, super durable polyester, epoxy, and urethane. Each of them has varying features and different properties especially when it comes to durability, temperature resistance, quality, industrial application, protection against corrosion, and the like. Understanding the differences of each coating will help you find the best option for your aluminum powder coating needs. Read on to learn more!

Polyester
Painting of machine parts

Polyester is one of the more widely-used materials for powder coating. As mentioned before, polyester powder coats are “electrostatically spray-deposited” (ESD) onto the surface of the aluminum or metal. In this regard, polyester is a great option because of the excellent adhesion that the coating offers for aluminum.

This type of powder coating can be further classified into triglycidyl isocyanurate (TGIC) and TGIC-free. While both offer durability, TGIC-free polyester coatings are preferred because they offer higher consistency suitable for batch powder coating or high-volume production. When coating smaller parts, TGIC-free coatings shine because of its ability to cover every nook and cranny on the material.

TGIC coating on the other hand, simply refers to the type of curing agent contained in polyester. They offer better stability to the coating, reduce wear and tear, and prevent yellowing on the material — a phenomenon wherein the powder coat can sport a milky-like appearance due to the thickness of the film or curing method.

On the manufacturing side, TGIC is a cost-effective option because it makes the spray deposition process much simpler. For the consumers market tier suppliers, both TGIC and TGIC-free are good choices due to the long shelf life, high coating quality, aesthetic finish, and non-volatility in different environments.

Super Durable Polyester

From the name alone, there shouldn’t be any question why the super durable polyester powder coating exhibits better properties on aluminum. This is an enhanced version of the polyester powder coating and creates not only a corrosion-resistant layer on the product, but also gives it a reliable UV-protection factor.

Unlike the typical polyester coating super durable polyester can last for as much as a decade more. For aesthetic value, super durable polyester gives off a cleaner, more consistent, and glossier look and feel for the aluminum. This is why this is the choice coat in architectural applications and other outdoor structures — think wall panelling, roofing sheets, beams, door frames, window frames, and the like.

While TGIC and non-TGIC polyester also offer corrosion-resistance and better protection against physical impacts, super durable polyester is built to last longer — perfect for tropical locations and environments like the Philippines.

Epoxy
Man placing epoxy on floor

Many of the benefits that the epoxy powder coating provides are a result of its molecular structure — epoxy compounds and systems have much larger molecules. Due to the size, epoxy powder coatings are more flexible, tougher, and elastic. Consumer goods and industrial products made out of epoxy — like epoxy flooring — are chosen precisely because of its features.

As a powder coating, epoxy can be applied in a wide variety of applications. Some examples are medical equipment, devices, automotive components, petrochemical tanks, filters, fittings, furniture, lighting equipment, consumer goods, and many more.

Similar to super durable polyester, epoxy powder coating also protects metals and aluminum products from extreme chemical changes, corrosion, wear and tear. But when it comes to added ultraviolet protection, the polyester coating is still the better choice.

Urethane

Urethane-based powder coatings like polyurethane are also similar to epoxy coatings, but offer better protection for outdoor environments. Urethane coatings are popular in applications that rely on chemical-resistance — think HVAC components, agricultural devices, automotive parts, and doorknobs.

One aesthetic advantage of urethane powder coatings is that dirt and grime become much less visible on the coated material. They also have high flexibility, adhesive, and chemical resistance, however, powder coating companies may be limited with the cure range that can be done with urethane coatings. These can also be expensive compared to epoxy and may not be as environmentally-friendly due to the compounds and smoke that they produce during curing/application.

Key Takeaway

In this guide, we’ve tackled four of the most common powder coating types in the metal alloy coating industry, namely polyester, super durable polyester, epoxy, and urethane.

All of these coatings have similar features such as better protection, excellent corrosion-resistance, and environmentally-friendly. However, some powder coatings are preferred than others. For example, wherever chemical exposure is a concern, urethane coatings are more ideal. For low cost options, epoxy and polyester powder coatings may be better.

Looking for high-quality powder coating services? AMC Aluminum can offer you all-around powder coating on all of their aluminum products. Click here to learn more! You may also get in touch with us for more information, suggestions, comments, and inquiries.


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