Everything You Need To Know About Powder Coat Finish

Welcome to IDEAL's ultimate guide to Powder Coat Finish!
Our blog is a comprehensive resource for anyone interested in learning more about this versatile and affordable surface finish option.

Powder coating is a popular finishing option in the rapid prototyping industry. It is a great way to impart improved physical and mechanical properties on custom machined parts. 

This method of coating has been used since the early days of powder metallurgy and has become increasingly popular. It is widely used in industry today because of its numerous advantages, including corrosion resistance, high-quality surface finishing, and long-term environment-friendly impact. 

So, what types of powder coating? how does it work? and tips for perfect powder coat finish. This article will address all of your concerns about powder coatings.

What is Powder Coating?

Powder coating is a type of coating that is applied as a dry powder to a surface and then cured under heat. The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a hard finish that is tougher than conventional liquid coatings, which can be used on plastic, glass, or metal surface.

The powder coating is usually done by electrostatic spray deposition (ESD) or fluidized-bed application. Both two methods provide great gloss levels, textures, various colors, and high-quality surfaces, making them used on a variety of products, including medical devices, architectural applications, automotive, and even fiberboard avionics.

Types Of Powder Coating

Powder coating is usually divided into two main categories. There are thermoplastic, thermosets. In addition, there are also divided into three categories, including Thermoplastic, Thermoset, and UV Curable Powder Coating. The UV curable is the most advanced technique.

This article will introduce three types of powder coatings. You can decide which type to choose based on the parts’ materials, durability, cost-effectiveness, and quality.

Thermoplastic Powder Coat Finish Materials

Thermoplastics are those which soften with heating and can be processed after that to gain specific strength and chemical properties with cooling. In thermoplastic powder coating, the dry powder is coated on desired part/material with heating the powder melts and covers the desired workpiece, and gains the specific mechanical strength on cooling.

Specifically for industrial purposes, thermoplastic coatings are implemented for endurance, esthetics, and safety purposes. Some of the thermoplastic powders used in the industry are mentioned below.

Nylon

Nylon is an excellent thermoplastic powder coating material with excellent durability and impact resistance. It is FDA approved and food graded, that is why it is commonly used in household and kitchen products such as dishwashers and for food storage items. It also has a low friction coefficient, which makes him ideal for the surface finishing of gears and mechanical Tools.

Polyvinyl Chloride (PVC)

The PVC coating is introduced in the market when the powder coating is in its initial stage, these coatings are pliable, sleek, and durable and show resistance to most of the solvents. polyvinyl-chloride is engineered with the polymerization technique in the presence of vinyl chloride, and it is produced in the industry on large scale. The basic benefit of these coating is in terms of chemical and electrical insulation. Moreover, they have excellent spray resistance, FDA-approved food staining resistance, and good dielectric and physical strength.

Polyester

The polyester coating is famous for its durable finish, weather and temperature resistance, esthetic look, and for its resistance to abrasions. For these reasons, this type is mostly used for outdoor automobile and avionics parts. Due to their aesthetic looks and physical strength, they are also ideal for architectural purposes.

Acrylic

Acrylic powder coating shows high-quality surface esthetics and high impact resistance, this process needs a little bit high curing temperature, that’s why it is mostly considered an expensive powder coating.

It shows excellent alkali resistance which is ideal to be used for components like washing machines and ship structures. Acrylic powder coating is applicable through electrostatic spraying to get ideal chemical resistance, weather ability outstanding smoothness, physical strength, and durability.

Thermoset Powder Coat Finish Materials

In thermoset powder coating The thermoset resigns are broken down to powder material, Which is fabricated on the desired material as a thin film. They provide improved chemical and physical characteristics in the aspect of esthetics, and corrosion resistance than ordinary oil coating.

In the modern, the thermostat material technology improved a lot, The ability to engineer thermostats resigns to increase their physical and chemical properties as per the targeted object, improving this niche a lot in specialized roles in surface finishing technique. The following are two common thermoset materials.

Thermoset Powder Coatings: These powders include resins that chemically react during curing, creating a solid, durable finish that won’t remelt under heat. They are common for outdoor applications due to their UV resistance and durability.

Thermoplastic Powder Coatings: These powders melt and flow when heated but do not chemically react. This makes them more flexible and impact-resistant, suitable for applications where flexibility is needed.

UV Curable Powder Coat Finish

UV curable powder coatings are a coating that cures under ultraviolet light. Unlike traditional methods, which require heat to cure, UV curable powder coatings can be cured at much lower temperatures. This makes them ideal for use on delicate or heat-sensitive materials. It also has a shorter curing time than traditional powder coatings.

UV curable powder coatings provide a number of advantages over traditional ones, including faster curing times, improved durability, and greater flexibility in terms of color selection. They are typically more expensive than traditional methods, but the improved performance can justify the additional cost.

How Does Powder Coating Process Work?

1. Preparation of the Surface

The success of powder coating depends on thorough surface preparation. This stage ensures that the powder adheres effectively and that the coating is even and durable. Steps may include:

Cleaning: Dirt, grease, and other contaminants are removed from the surface using degreasers or solvents.

Abrasive Blasting (Sandblasting): If there are old finishes, rust, or stubborn residues, sandblasting or another abrasive method is used to strip the surface.

Chemical Treatment: In some cases, a chemical etching or conversion coating (like a phosphate or chromate treatment) is applied to enhance corrosion resistance and improve powder adhesion.

2. Application of Powder

After preparation, the powder is applied using an electrostatic spray gun in a controlled environment:

Electrostatic Charging: The powder particles (made of finely ground pigment and resin) are given an electric charge as they exit the spray gun.

Electrostatic Attraction: The charged powder particles are attracted to the grounded metal part, forming an even layer across the surface.

Uniform Coating: The electrostatic process ensures that the powder adheres uniformly, even in hard-to-reach areas, and minimizes overspray waste.

3. Curing Process

Once the powder is applied, the part is transferred to a curing oven where heat causes the powder to melt, flow, and form a continuous, durable film. The curing process involves:

Heating: The coated part is placed in an oven and heated to temperatures between 300-400°F (150-200°C), depending on the powder type.

Cross-Linking Reaction: During heating, the powder melts and undergoes a chemical reaction (cross-linking) that bonds the molecules, creating a hard and smooth finish.

Cooling: After curing, the part is left to cool, which solidifies the coating and leaves it highly durable and ready for use.

Benefits of Powder Coating

Powder coating offers several advantages over traditional liquid paint:

Durability: Powder-coated surfaces are resistant to chipping, scratching, and fading.

Environmental Benefits: Powder coating is a more eco-friendly option because it doesn’t use solvents, resulting in minimal volatile organic compound (VOC) emissions.

Efficiency: Overspray can often be collected and reused, reducing waste.

Attractive Finish: Powder coating provides an even, vibrant finish and can achieve a wide range of textures and colors, including matte, glossy, and metallic effects.

Common Applications of Powder Coating

Powder coating is used on a wide range of products and components. The powder coating process involves cleaning and prepping the surface, applying an electrostatically charged powder, and curing it in an oven. This method provides a resilient, attractive, and environmentally friendly finish, making it a popular choice for industrial, automotive, and consumer products alike.

Automotive and Motorcycle Parts: Such as wheels, frames, and engine components, due to its durability and resistance to high temperatures.

Appliances and Furniture: Refrigerators, washing machines, and outdoor furniture are often powder-coated for protection and aesthetic appeal.

Industrial Equipment: Toolboxes, racks, and machinery are powder-coated for improved durability in harsh environments.

Conclusion

At IDEAL, we excel in providing top-quality custom machining services tailored to meet your project needs. Our advanced technology and skilled team ensure your specifications are met with exceptional accuracy and efficiency.

Contact IDEAL today to see how we can assist with your next project!