What is Powder Coating? When to Use it and How to Apply it

Takeaways

Powder coating protects metal components against corrosion, weathering and surface wear.
Powder coating forms part of Argos ST’s Industrial Coatings portfolio, along with cataphoresis and liquid enamel painting.
The choice between polyester, epoxy or hybrid coatings depends on the intended usage environment and performance specifications.
Epoxy coating offers high resistance to chemicals, while polyester powder coatings guarantee excellent performance outdoors.
Correct preparation of the surface is essential for proper adhesion, uniformity and durability of the coating.

Industrial coating uses multiple technologies

When it comes to the surface protection of metal components, the term “coating” can refer to a range of different technologies, each designed to meet specific application requirements.

Through its Industrial Coatings business unit, Argos ST offers a comprehensive range of treatments including cataphoresis, powder painting and liquid enamel painting. Drawing on this technological portfolio, the company can identify the optimal cycle based on material, usage environment, performance levels and aesthetics.

Power coating is one of the most widespread of these technologies for the protection and finishing of metal components, including those intended for use under particularly demanding conditions.

What is powder coating?

Powder coating involves the electrostatic application of an enamel powder onto the surface of a component.

The powder is applied using automatic electrostatic spray guns that distribute the protect uniformly across the surface. In the curing oven, the polymer coating forms a seamless film that protects the component from corrosion and improves its aesthetic finish.

The result is a coating that serves both a protective and a decorative purpose, increasing the resistance of the component and enhancing its aesthetic qualities.

Why choose powder coating?

Powder coating is popular for its ability to offer both technical performance and an outstanding aesthetic finish.

Key advantages of this treatment include:

excellent protection against weathering
good UV resistance
highly uniform coating film
wide range of colours, finishes and levels of surface sheen
very durable coating.

Essentially, electrostatic distribution of the powder enables a uniform coating even on complex structures. This provides a uniform thickness and a seamless surface for components with greater protection and more refined aesthetics.

This is why powder coating is used in many different spheres, including the automotive, commercial-vehicles, agricultural-machinery, earth-moving equipment and general-engineering industries.

Polyester, epoxy, and epoxy-polyester coatings and other formulations: what are the differences?

Powder coatings are selected based on the operating environment, the level of protection required, the aesthetic context and the function of the component. Argos ST can apply a range of epoxy, epoxy-polyester, polyester, polyurethane and acrylic coatings, in addition to epoxy primers and coatings formulated to withstand high temperatures.

Polyester powder coating

Polyester powders are particularly suitable for components intended for outdoor use. They offer good resistance to weathering and UV radiation, helping to maintain the colour tone, uniformity and aesthetic finish of the coating.

These solutions are often applied to components for motor vehicles, agricultural machinery, industrial vehicles, earth-moving equipment and metal structures exposed to weathering.

Epoxy coating

Epoxy coating is used when a project requires a high level of adhesion to the substrate, chemical resistance and corrosion protection. Epoxy formulations are ideal as protective primers in multilayer cycles and in applications where the component may come into contact with acids, alkalis, hydrocarbons or other chemicals.

Epoxy resins provide lower UV resistance than polyester powders. For this reason, they are used primarily indoors, as a primer or as a base with a subsequent finishing coat.

Epoxy-polyester coating

Epoxy-polyester powders combine the properties of epoxy and polyester resins. They offer strong adhesion, mechanical resistance and aesthetics, making them ideal for components intended for indoor environments.

These formulations represent a balanced solution for applications requiring surface uniformity, resistance to wear and a refined finish.

Polyurethane and acrylic coatings

Polyurethane and acrylic powders can be considered when a project calls for specific aesthetic or functional characteristics, such as high sheen, colour stability, surface hardness or a particular quality of finish.

They are applied according to customer specifications, the shape of the component and the conditions expected during intended use.

High-temperature coatings

For components exposed to high temperatures, Argos ST offers coating cycles formulated to preserve the adhesion and protective function of the coating even under thermal stress.

The maximum operating temperature and the polymerisation cycle are assessed based on the material, the mass of the component and the required performance levels.

Cycles combining cataphoresis with powder coating

When a component requires a greater level of corrosion protection, powder coating can be applied over a cataphoresis layer. Epoxy cataphoresis creates a uniform, adherent base layer and is capable of coating inside cavities, deep folds and areas that are difficult to reach with spray application.

The subsequent powder finish completes the cycle, adding resistance to weathering and a refined finish. The combination of cataphoresis and powder coating is particularly suited to components intended for the automotive, truck, agricultural machinery and earth-moving industries.

The role of surface preparation

The quality of powder coatings depends largely on preparation of the component prior to application. A surface contaminated with oils, working residues, oxides or mill scale can compromise adhesion, uniformity and durability of the coating film.

Therefore, Argos ST includes targeted pretreatments in its production cycles, based on the type of material, the shape of the component and the properties required. The process can include high-temperature degreasing with alkaline products, rinsing with mains and demineralised water, surface activation and zinc, nickel and manganese phosphate coating. In the case of aluminium, dedicated treatments may be applied to increase surface activation and promote coating adhesion.

If the component show signs of oxidation, mill scale or surface irregularities, the cycle may also include grit-blasting or sandblasting, following verification of its thicknesses and properties. These processes may be accompanied by sealing, filling and assembly operations, depending on project specifications.

Surface preparation therefore represents a critical process phase. It establishes the necessary conditions for a uniform, stable and durable coating, reducing the risk of detachment, aesthetic defects and premature loss of protective properties.

Technology, control and production capacity

The quality of industrial coatings does not depend on the powder formulation alone, but on the ability to control every stage of the process and ensure consistency.

This is why Argos ST uses fully automated lines, designed to ensure application uniformity, treatment repeatability and consistent quality even with high production volumes. Handling systems and coating equipment allow adaptation of processes based on the shape and dimensions of the component, while dense-phase technology enables a more uniform distribution of the powder, with improved coverage, controlled thicknesses and a high-quality surface finish.

Plant flexibility also enables handling of both small parts and components as well as large elements, such as frames, chassis, bodyshells and platforms for the truck, automotive and heavy-machinery industries.

Production is supported by an inhouse laboratory that carries out checks on the coatings and verifies compliance with specifications. This helps to ensure consistent performance and treatment conformity throughout production cycles.

Powder coating as part of a wider process

Powder coating is a well-established technology, but its effectiveness depends on its integration into the correct surface treatment cycle. Substrate metal, component shape and dimensions, operating conditions, aesthetic requirements and performance all guide the choice of the best solution.

On this basis, Argos ST works closely with its customer from the early stages of each project, assessing whether powder coating is the most effective option or whether it should be combined with other treatments from the Industrial Coatings portfolio, such as cataphoresis or liquid enamel painting.

We do more than just apply coatings. We design a surface protection cycle that can ensure reliability, refined aesthetics and long-term durability, contributing to the performance and value of the finished component.