Powder coating is a dry finishing process that has become very popular since its introduction around 40 years ago. It now represents around 15% of the total industrial finishing market and is used on a wide variety of products. More and more companies specify powder coatings for a high-quality, durable finish, allowing for maximized production, improved efficiencies, and simplified environmental compliance. Used as protective and decorative finishes, powder coatings are available in an almost limitless range of colours with excellent performance properties.
How Powder Coating Works
Powder coatings are based on polymer resin systems, combined with curatives, pigments, levelling agents, flow modifiers, and other additives. These ingredients are melt mixed, cooled, and ground into a uniform powder similar to baking flour. A process called electrostatic spray deposition (ESD) is typically used to achieve the application of the powder coating to a metal substrate. This application method uses a spray gun, which applies an electrostatic charge to the powder particles, which are then attracted to the grounded part. After application of the powder coating, the parts enter a curing oven where, with the addition of heat, the coating chemically reacts to produce long molecular chains, resulting in high cross-link density. These molecular chains are very resistant to breakdown. This type of application is the most common method of applying powders. Powder coatings are easy to use, environmentally friendly, cost effective, and tough!
Durability of Powder Coating
Powder coating is a high-quality finish found on thousands of products you come in contact with each day. Powder coating protects the roughest, toughest machinery as well as the household items you depend on daily. It provides a more durable finish than liquid paints can offer, while still providing an attractive finish. Powder coated products are more resistant to diminished coating quality as a result of impact, moisture, chemicals, ultraviolet light, and other extreme weather conditions. In turn, this reduces the risk of scratches, chipping, abrasions, corrosion, fading, and other wear issues.
It’s tough. It looks great. And it lasts a long, long time. In addition to being durable, powder coating is an attractive choice due to environmental advantages.
Many issues inherent in liquid paint finishing are eliminated or minimized with the powder coating process. Liquid finishes contain solvents, which have pollutants known as volatile organic compounds (VOCs). Powder coatings contain no solvents and releases negligible amounts of VOCs into the atmosphere, if any. Thus, there is no longer a need for finishers to buy costly pollution control equipment, and companies can comply more easily and economically with current regulations.
The benefits of powder coating for consumers are simple: powder coating will make your purchase look better and last longer, not to mention its reduced environmental footprint.
Powder coating is already found on thousands of products that you come in contact with every day. From bulldozers and chainsaws to coffee machines, powder coating protects the roughest, toughest machinery as well as the household parts that you depend on daily. The result of choosing a powder coated product is that it will have the most attractive, durable, high-quality finish available.
The powder coating process itself offers another advantage – it is environmentally friendly and virtually pollution-free! Unlike liquid paint, no solvents are used in powder coating, so only negligible amounts of VOCs are released into the air. In addition, unused or over sprayed powder can be recovered, so any waste is minimal and can be disposed of easily and safely. Choose powder coating and do your part to preserve the environment.
Powder coating is a clean process. In fact, one of the major elements in expanding the market for powder coating has been the implementation of stringent air pollution control legislation over the past 30 years or so. In addition, the increased efficiencies of applying a powder coating generally produce lower operating costs. For example, powder coating overspray that does not adhere to the part can be retrieved and reused. The unused powder is reclaimed by a recovery unit and returned to a feed hopper for reuse. Any powder waste that results is minimal, and can be disposed of easily, economically, and safely.
In addition to being the more durable and attractive choice, powder coating is also highly protective of our environment. Negligible HAPs (hazardous air pollutants) Free. Powder coatings contain no solvents and therefore emit negligible, if any, polluting VOCs into the atmosphere. Powder coating is a clean process, allowing exhaust air from the coating booth to be returned to the plant, and less oven air is exhausted to the outside. Heating and cooling costs are eliminated for make-up air and the cost for maintaining oven temperatures is minimized. Powder overspray can be retrieved and reused. There is no costly waste disposal equipment needed and unused powder can be reclaimed and returned to a hopper for recirculation through the system, with negligible waste.