Coil Coatings’ Importance

Coil coating is the industrial process for efficiently applying coatings to metal. Because the metal is processed before it is cut and formed, the entire surface is cleaned and treated, providing tightly bonded finishes. Formed parts can have many holes, recessed areas, valleys and hidden areas that make it difficult to clean and uniformly paint.… Continue reading

Coil Coatings’ Importance

Coil coating is the industrial process for efficiently
applying coatings to metal.

Because the metal is processed before it is cut and formed, the entire surface is cleaned and treated, providing tightly bonded finishes. Formed parts can have many holes, recessed areas, valleys and hidden areas that make it difficult to clean and uniformly paint. Coil coated metal (often called prepainted metal) is considered more durable and more corrosion-resistant than most post-painted metal. To those of us in the metal construction industry, we sometimes don’t realize how important coil coating has been to the growth of our markets over the years. The coil coating process was invented for manufacturing Venetian blinds, and then quickly grew into a process that soon became vital to many building and construction products, thus allowing the industry to grow and prosper.

Painted aluminum siding, painted gutters, downspouts, soffits and facia all became growing markets in the early years of the coil coating business. Today, we see prepainted products everywhere, both inside and outside of all types of buildings and homes.

Whether it’s a roof on a commercial building, the insulated wall panels on a convention center, the raised panel entry doors on a home, the garage doors on a factory, or even the HVAC that controls the structures’ climate, the coil coating process was involved in making those products what they are today.

Beautiful standing seam roofs and stamped metal shingles offer both the highest level of performance and the most aesthetically versatile product capabilities available to today’s architects, contractors and building owners. Complete the entire building envelope with insulated metal wall panels with prepainted metal skins, and you will have the most thermally efficient, high-performance and beautiful building structure that can be built today.

In so many ways, it all begins with the coil coating process. Coil coating is a continuous process that starts with cleaning metal and applies a pretreatment to the metal’s surface. This prepares the metal surface, and ensures adhesion of the primer and paint to the surface on both sides. It also enhances corrosion resistance and long-term field performance of the painted finish. Next a primer and finish coat are applied to the metal. Paint companies today have engineered a wide range of high-performance, vibrant coating systems that can be matched exactly to any color of choice. Those coatings are roll applied on a coating line that precisely controls the film thickness of the primer and finish coating system. Paints can be specifically engineered and designed for the end-use environments, such as a sea coast climate. Film thickness of the primer and top coat can be increased to enhance the paint’s field performance and durability based on the eventual end-use location.

Long, natural gas fired ovens then cure the primer and finish coatings at temperatures in the 450 F range. The coil coating process itself is the most energy-efficient, environmentally green, low-cost process for applying coatings to metals. In fact, today most of the solvent used to make the paints is actually burned off and that energy is recycled back into the ovens, thus reducing the natural gas consumption needed to fire the ovens.

Once those coatings are cured, the coil is wrapped up at the end of the coil coating line. The coil coaters’ quality control lab then tests every coil and certifies the exact film thickness, precise color readings, bonded paint adhesion to the metal and paint flexibility. The coater typically will hold onto a retain from every coil as part of the extended warranty process offered with many paint systems.

The painted coil is now certified and ready to be shipped. The color is a custom-chosen match and the product is ready to be rollformed, stamped, bent, folded and manufactured into a product that will enhance any construction project by providing a long-lasting, high-performance and beautiful prepainted metal product. It all became possible because of the coil coating process and the high-performance paint systems that are applied on today’s many coating lines across the country.

Jim Dockey is the coating services director at CENTRIA Coating Services, Moon Township, Pa. To learn more, visit www.rollwithcentria.com.