What is the Process of Powder Coating?

It’s a pain to paint metal parts. It is time-consuming, messy and not precise. You’ll have to deal with runoff, dripping, and uneven coatings. The coating won’t last after painting. The paint has to be touched up repeatedly and eventually the paint becomes so thick, that it needs to be removed and repainted.

Here’s a look at how powder coating works as an alternative to painting.

What is Powder Coating?

Powder coatings are an environmentally-friendly and easy to use alternative to painting. They provide a coating that’s nearly indestructible and permanent. The electrostatic process uses dry powder with an electric charge in order to produce the final finish.

Understanding Powder Coating

Powder coating is a process that involves the application of color to metal components. The most common projects are wrought iron fences and outdoor home detailing. Other popular projects include automotive parts, gas stoves, agricultural equipment and kitchen mixers. The pigment is first applied as a powder and then to the surfaces to be painted.

The powdered surface is exposed to heat, and then electrical charges. Powder melts, undergoes chemical bonding and hardens into a solid surface that conforms perfectly to the surface. Powder coatings are more durable and cheaper than paint.

Types of Powder Coating

You may not have known that powder coatings come in many different varieties, some of which are more suitable for your desired finish. Let’s take a look at the different types of powder coats.

• Epoxies: The first powders widely used, epoxies adhere very well to the surface of an item being coated. Unfortunately, their amazing adhesion power is offset by a poor performance in terms of durability.
• Polyesters: These are the most widely-used powders and offer great value. These powders are available in an array of colors and gloss levels. They can also be used to create special effects.
• S upper Durable Polyesters: These offer all the benefits of polyesters, plus the added benefit of maintaining their color and gloss over a period of 10 to 15 years.
• Epoxy/Polyester hybrids: These combination epoxies are resistant to overbaking and produce ultra-smooth thin films. These resins are also more cost-effective than pure epoxy.
• Fluoropolymers: These fluoropolymers offer exceptional weathering properties as well as world-class color and shine retention. These powders are commonly used in architectural projects.
• Urethanes: These powders are chemically similar to polyesters but use a different curing agents. They offer a smooth finish and good durability.

Process of Powder Coating

Three steps can be taken to break down the entire process. To achieve a flawless powder coating, each of these steps needs to be followed. Powder coating non-metallic surface may require a slightly different process due to the material requirements.

Cleaning

It is important to thoroughly clean the surface before applying powder coating. The item must be free of any grease, dirt, or oil. It includes any oil on the skin that might have been transferred by handling the item. When cleaning, it is common to use a sandblaster to remove debris and then brush to remove any remaining grit or moisture.

How to Apply the Powder Coat

After cleaning, the item will be connected to an electrode to give it a charge. A Corona gun is used to apply the powder. It is similar in design to a paint can, but it contains a thermoset polymer (heat-curing) that has a negative charge. The positive and negative electrical charges of the powder are attracted by each other as it is blown onto the part. This causes the powder to stick to the item like static electricity makes a balloon stick to a wall.

Thermoset Treatment

The item is then placed in an industrial oven. The powder is baked onto the item in the oven. Powder does not melt on the piece, but some powder carbonizes due to heat. This process produces no visible gas or smoke. The carbonized powder is then bonded to the remaining powder on a molecular basis.

The bonded surface is extremely resistant to scratching, chipping or wear. The part is then ready for use, and a vibrant color coat that matches the contours of the item has been applied.

Benefits of Powder Coating

Powder coating is a great alternative to painting for many projects.

• Non-chipping, nearly-indestructible coating
• Powder coat protects the surface beneath the powder coat
• Paint is not as environmentally friendly as it may seem
• Durable in any environment (indoors/outdoors/all-weather).
• High efficiency: almost waste-free process
• High-quality finish
• Low Cost
• Color variety

Your Powder Coating Experts

You have metal items that need a color splash or a durable finishing. Powder coating could be the perfect solution for you. We can answer any questions you may have about powder coating metal parts. Please feel free to browse our services and contact us for more information.