Paint is a traditional approach with various limitations. Powder coating, on the other hand, is a more advanced approach. It brings improved durability, a reduced environmental impact, and a higher quality appearance.
WHAT EXACTLY IS POWDER COATING?
Powder coating is a dry coating process used as a metal finish mostly on industrial equipment. Powder coating is applied as dry powder through an electrostatic process, then cured with heat. It is well known for providing high-quality finishes in terms of both functionality and overall look.
The powder coating finishes are not only sturdy but flexible as well. It can be used on different surfaces, including metal, concrete, steel, and plastic. It’s suitable for both indoor and outdoor applications, and it’s one of the most cost-effective finish options.
TYPES OF POWDER COATING
There are two types of powder coating, thermosets and thermoplastics.
Thermoplastic powder coating finishes become liquid and very soft when heated. This eliminates chemical bonding. This process makes the powder coating both reversible and reusable.
Thermoplastic coatings tend to be thicker, and hence more durable compared to thermoset coatings. For this reason, they can be used for a plethora of things from metal, auto parts, and even refrigerators.
On the other hand, thermoset powder is quite different in the fact that it forms chemical bonds once cured, making it impossible to recycle it. It is suitable for high heat areas because the bonds prevent it from melting away. This type is much cheaper compared to thermoplastic.
THE APPLICATION PROCESS
Preparation is the first step of the process and perhaps the most important one. This step determines how well the powder coating adheres to the metal surface, and there are various options for cleaning and prepping the surface. Using a degreaser and/or phosphate rinse is ideal, followed by a quick water rinse. The powder is then applied using the spray gun, and curing begins right after that.
There are other methods that may be used, but they are only suitable for specific projects.
HOW DOES POWDER COATING METAL WORK?
Powder coating is based on polymer resin combined with pigments, curative, flow modifiers, leveling agents, and several other additives. All ingredients are melt mixed together, then cooled and ground into a powder. Preheating achieves a uniform finish, and cooling helps form a hard coating.
The powder coating process eliminates overspray wastage that may be experienced with solvent-based paints. Powder coatings are different from paint in the fact that they need an electric charge to work, while paint needs an adhesive.
An electrostatic paint sprayer is used for the application process. It imparts a positive electric charge on the powder and accelerates it towards the components through an electrostatic charge. The chemical bonding process strengthens the powder coating because once cured, the bonds solidify.
One of the most significant advantages of using powder coatings is that once solidified, more layers can be added id thickness is desired. Thicker coatings mean longevity and increased protection. Powder coatings are suitable for metal because they repel corrosive materials, such as chemicals and water.
HOW DURABLE IS POWDER COATING?
This is hands down one of the most durable coatings you could use as a finish for a variety of surfaces, not just metal. The chemical bonds give a superior coating that makes it suitable for both machinery and everyday items. It holds well to extreme weather and physical impact, meaning it’s resistant to scratches, abrasions, and chips.
HOW LONG DO THE POWDER COATING FINISHES LAST?
The longevity of the product will highly depend on several factors. These factors include the quality of preparation, type of powder coating used, and the environment in which the product is exposed. Powder coating finishes can last up to 40 years, but due to the consistent use, exposure to UV light, and outdoor environment may break it down faster, so 20 years is not an unreasonable expectation.
Different coatings also have varying lifespans. For instance, coatings that have fluoropolymers and urethanes can last longer. They are designed to withstand extreme conditions and are better suited for outdoor products. Epoxy coatings, on the other hand, may last very long indoors, but once exposed to the outdoors, they break down a lot faster.
OTHER ADVANTAGES OF CHOOSING POWDER COATINGS
Powder coatings have several advantages, which makes them an excellent choice for metal fabrication. Apart from the legendary durability, here are more strong points that you may want to consider when choosing a finish
