Powder Coating vs. E-coating
Developed near the same time around the turn of the 20th century, powder coating and e-coating were both responses to rising environmental concerns posed by liquid coating. Tracked from similar histories, both methods utilize similar principles involving charged particles and, generally, metallic products. The methods also now compete in many of the same spheres, though unique advantages and disadvantages have each won them acceptance in different fields with different products.
Though both methods were developed to minimize environmental impacts and increase coating efficiency, e-coating wins the battle on being green. While most powder coating methods by their nature introduce powder into the air, which must be filtered out before the air can be reintroduced, e-coating keeps paint and finishes in the application bath. While both methods aim to minimize HAPs and VOCs, the e-coating process's additional potential to reduce waste and reclaim excess paint in the application bath, instead of filtering it through the air, makes it generally more efficient.
While e-coating, like powder coating, can be designed with many different purposes and used with many different products, the type of coating and the type of products are more difficult to switch. Changing the immersion bath, cleaning the equipment and reconfiguring the system with the appropriate charge is such a long and expensive process it is seldom cost-effective unless the entire operation has changed. The type of finish or color used in e-coating is there to stay, often for thousands of units. Simply loading new powder into an application gun, by contrast, can change powder coating.
Both powder coating and e-coating are used to apply finishes that are resistant to weathering, corrosion, rust, chipping, cracking, and other damages. Both processes can be applied to substrates that provide durable finishes, though some e-coating techniques do not provide resistance to UV light. Powder coating is generally used to apply thicker coats; while e-coating can be used when thinner finishes are desired. Because the object is completely suspended in the immersion bath and the paint or finish is attracted through charge, it is easier to fill in hard-to-reach spaces through e-coating. Each coating strategy offers varying benefits depending on the type of object being coated.
Popularity and Growth
Integrating e-coating processes requires higher start-up costs than powder coating and is, therefore, more common in the automotive industry, construction equipment, and agricultural equipment. Likely due to high start-up costs and its high level of versatility, the popularity of powder coating has vastly outpaced e-coating. The powder coatings market is expected to reach $12.48 billion by 2020, while e-coating is expected to reach $3.69 billion by 2020. Neither market is expected to significantly detract from the other, but rather both are expected to replace the less efficient, more hazardous liquid coating market.