Powder coating is a finishing process that consists of applying a dry powder to a metal surface. It is an alternative to using a liquid paint or solvent.
The powder coating can be formulated with different components that are mixed and processed into a solid. The solid is broken down and granulated into a fine powder.
Not all powders are alike though. Learn more about what creates a quality finish with Minnesota Industrial Coatings.
Why Do You Need a Finishing Process for Metal?
Raw metals, exposed to the elements, end up tarnished and corroded. The durability and strength of the metal are lost due to oxidation. Unfinished metals degrade due to UV exposure, salt, and rain.
Adding a metal finish, such as paint, electroplating, or powder coating, protects metals from the elements. It also improves the look of the final product. Both qualities increase the part or product’s value and make them look more attractive to the consumer.
Metal fabricators often use liquid paints, which are solvent-based, to finish metal. Liquid paint does a fair job of protecting metals, but it can be expensive and takes time.
Chrome plating is another frequently used method. However, it is also costly and time-intensive.
Powder coating is a dry coating process that coats metals with epoxy, polyurethane, fluoropolymers, polyester, or urethane. Powder coating is quick, more eco-friendly than other options, and can be formulated to solve several issues.
Types of Powder Coat Formulas
Different formulations of powders provide a wide range of melt viscosities and can be applied over a wide range of film thicknesses. There are powder coating formulations available for almost any metal application.
Epoxy – Epoxy is durable and provides resistance to corrosion and chemicals. It should be used on products or components used indoors, as outdoor elements can cause fading and deterioration. Epoxy is a good primer. When combined with a UV top coat, your part or product will last for years.
Polyester – Polyester is a commonly used powder and comes in a wide range of colors and glosses. Polyester is great for indoor and outdoor use. Polyester’s durable chemistry provides resistance to corrosion, UV weathering, and chemicals.
Fluoropolymers – Fluoropolymers provide excellent weathering capabilities and retain their gloss and color. Fluoropolymer powder coating is resistant to corrosion and is a perfect choice for outdoor applications.
Urethanes – Urethane powder coating and polyester share many of the same characteristics. However, urethane resists chemicals better. Urethane powders create a more complex finish that is less flexible than other finishes.
Three Reasons Industrial Powder Coating Services Are Popular With OEMs
- Cost Savings
Powder coating materials are less costly than those required for painting or electroplating. Since there are fewer materials needed for powder coating, storage requires less room.
Liquid paint can require multiple coats to achieve the same aesthetic as a single coat of powder, potentially doubling the cost of base materials. Powder coating is a one-and-done coating.
The base product for powder coating allows the process to cover more area than most other liquid painting processes. Single coating vs. multiple coatings translates into lower material costs.
Powder coating is a much more efficient material. Almost 98% of overspray powder can be collected and reused. Painting can reclaim less than 30% of liquid paint spray. Additionally, powder has lower disposal costs than liquid paints or solvents.
Environmental regulation and safety standards heavily affect the finishing industry because most formulations involve volatile organic compounds. Volatile organic compounds require special handling due to their hazardous and explosive nature. VOCs are a source of industrial pollution and a health hazard.
Because they do not contain any fluids or solvents, powder coatings do not emit volatile organic compounds. They are not a pollution or health risk and are safe to store and apply. The eco-friendliness of powder coatings translates into low mitigation risk and insurance premiums.
Powder coating lasts longer than paint coatings and can handle the wear and tear like no other finish. Powder coating is resistant to wear, chipping, and scratches because it thermally bonds to the metal surface during the curing phase. Additionally, powder coating can be applied in thick layers, unlike paint sprays that require multiple layers.
In addition to the physical hardness of the surface, powder coating retains color longer than painted surfaces. Exposure to sunlight, heat, and moisture over time will break down the resins found in paint and powder coating. This process is referred to as chalking.
Chalking causes the adhesion in pigment particles to erode. Severe chalking will eventually degrade the coating enough to destroy the metal protection. Due to their exceptional resistance to chalking, polyester formulated powder coatings make excellent top coats.
Powder coating is:
- Twice as thick as most paints
- Flexible, and will bend and yield with vibration and jarring
- Highly resistant to chipping and scratching
- Resistant to fading, corrosion, chemicals, UV light, moisture, and weather
Powder coating won’t leave paint globs, streaks, runs, or undercoated areas. It doesn’t create bubbles, bumps, or ripples. Metal fabrication projects finished with powder coating have a uniform and smooth look.
You can find a powder coating finish in nearly every color imaginable. Choose from high-gloss, semi-gloss, or matte finishes to get the look you desire. You can even add glitter, textures, or metal flakes!
The Powder Coating Process
Before a powder coating is applied, the surface needs to be cleaned and free of oil, dirt, or any other contaminants that could prevent surface adhesion.
Dry powder is deposited via a powered electrostatic applicator onto the metal surface. The applicator provides a negative charge to the powder, allowing it to be attracted to the metal part. The result is a fast, even application.
Once the powder coating reaches the desired level of thickness, the metal part is placed in a curing oven to harden the powder coating. The curing process thermally bonds the powder particles to the metal creating a hard, smooth finish.
Powder coating includes a primer and color coat. No additional color coats or clear top coats are necessary. In addition, there are no paint drips or sags.
Minnesota Industrial Coatings (MIC) has made a significant investment in powder coating ingredients, electrostatic booths, ovens, spray materials, tools, and hangers. Our coating experts work with each customer from planning to shipping.
MIC uses the highest-quality powder coating technologies and eco-sensitive, quality-driven processes. For those projects that are not suitable for powder coating, we offer electrocoating (e-coating).
Let Minnesota Industrial Coatings be your choice for quality industrial finishing.