One of the most notable appeals of powder coating is that it generates less waste due to a high material utilization rate.
First, unlike liquid paint which is always a spray-to-waste process, powder overspray can be reclaimed and recycled, depending on the capabilities of the coater, the number of colors utilized, the absence of contaminants and financial considerations related to the quality of the powder.
Second, because powder coating is an electrostatic process that applies charged particles to a grounded part, more paint ends up on the substrate, even on hard-to-reach areas.
Third, powder coatings often deliver better protection in a single coat in terms of coverage, corrosion resistance and weathering than two-coat liquid systems, which reduces the overall amount of product needed.
Finally, since powder has a long and stable shelf life, it retains its quality with proper storage even after long periods of time so product loss is minimized.
In fact, according to the Powder Coating Institute (PCI, Lakewood Ranch, Fla.), with proper application equipment, powder materials and efficient recovery methods, one-coat application, powder can achieve a 95-98% utilization efficiency rate; this is compared to the average of 60% material utilization with a comparable liquid system.
Generally, powder has advantages that are hard to overlook but newer high-transfer efficient advancements take these benefits to the next level.
Better First-Pass Build Rates
Because it is an electrostatic process that applies electrically charged paint particles to a grounded part, powder has excellent adherence to metal substrates.
But newer generations of high transfer efficient (HTE) powder coatings take that coverage to the next level by improving first-pass application build rates, the percentage of powder that gets deposited on the part.
These specialized coatings are engineered to deposit powder consistently and uniformly across complex parts and are formulated to electrostatically wrap and penetrate into deep recesses or hard-to-reach surfaces, achieving first- pass efficiency rates of up to 85%.
Powder coating is a dry finishing process in which free-flowing, thermoplastic or thermoset powder material, rather than a liquid suspension, is applied to a surface, melted, and then allowed to dry and harden into a protective coating. Typically, the powder is applied via electrostatic spray deposition (ESD) to an electrically grounded metal substrate. Once the powder coating is completely applied to a part, it is then heat cured in an oven until the powder melts and flows together. Powder coatings can also be applied by dipping preheated parts into powder material within a fluidized bed. The powder melts and fuses with the part’s heated surface upon contact. In either case, as the part dries and cools, the cured powder forms a smooth, hard finish.
Powder coating services are suitable for various materials, including metals, plastics, glass, and medium density fiberboard (MDF), and can provide both functional and decorative surface coatings in a wide range of colors, styles, finishes, and textures that are not easily achievable by conventional liquid coating methods. Powder coatings are also comparatively durable, cost-effective, and environmentally-friendly. However, they may not be suitable for all manufacturing applications, such as for low budget, thin film, or large part coating applications.
While each coating method has its advantages and disadvantages, this article focuses on powder coating. It explores the benefits and limitations of the powder coating process and provides comparisons between the powder coating and liquid coating methods.
Advantages and Benefits of Powder Coating
Compared to conventional liquid coating methods, there are several advantages and benefits of powder coating. These include:
- More durable coatings
- Capabilities for thicker and specialty finishes
- Less environmental impact
- More efficient curing and drying processes
- Greater material utilization
The powder coating process produces a long-lasting and durable, hard finish that is both protective and decorative. Demonstrating more resistance to impact, moisture, chemicals, and extreme weather than most liquid coatings of similar thickness, powder coatings offer a part or product greater protection from scratches, chipping, abrasions, corrosion, fading, and general wear. They can also act as electrical insulators and can withstand hundreds of hours of salt spray contact. For colored powder coatings, even after being subjected to extreme environments, the color remains brilliant and vibrant. This durability makes powder coatings well-suited for abrasive, high traffic, or high use areas, as well as diminishes the need for future coating touch-ups or replacement.
Read more: Benefits and Limitations of Powder Coating