![]() A wide range of speciality effects are easily accomplished using powder coatings that would be impossible to achieve with other coating processes.Powder coated items generally have fewer appearance differences than liquid coated items between horizontally coated surfaces and vertically coated surfaces.Powder coatings can produce much thicker coatings than conventional liquid coatings without running or sagging.Companies can comply more easily and economically with environmental regulations, such as those issued by the U.S. Thus, there is no need for finishers to buy costly pollution control equipment. Powder coatings contain no solvents and release little or no amount of volatile organic compounds (VOC) into the atmosphere.However, if multiple colors are being sprayed in a single spray booth, this may limit the ability to recycle the overspray.Īdvantages over other coating processes Powder coatings have a major advantage in that the overspray can be recycled. At the professional scale, the capital expense and time required for a powder coat gun, booth and oven are similar to a spray gun system. One variation of the dry powder coating process, the Powder Slurry process, combines the advantages of powder coatings and liquid coatings by dispersing very fine powders of 1–5 µm sized particles into water, which then allows very smooth, low film thickness coatings to be produced.įor garage-scale jobs, small "rattle can" spray paint is less expensive and complex than powder coating. There are very specialized operations where powder coatings of less than 30 µm or with a Tg below 40 ☌ are used in order to produce smooth thin films. Many manufacturers prefer to have a certain degree of orange peel since it helps to hide metal defects that have occurred during manufacture, and the resulting coating is less prone to showing fingerprints. The surface texture which is considered desirable or acceptable depends on the end product. For such powder coatings, film build-ups of greater than 50 μm may be required to obtain an acceptably smooth film. Most powder coatings have a particle size in the range of 2 to 50 μm, a softening temperature Tg around 80 ☌, a melting temperature around 150 ☌, and are cured at around 200 ☌ for a minimum of 10 minutes to 15 minutes (exact temperatures and times may depend on the thickness of the item being coated). As the film thickness is reduced, the film becomes more and more orange peeled in texture due to the particle size and glass transition temperature (Tg) of the powder. While it is relatively easy to apply thick coatings that cure to smooth, texture-free coating, it is not as easy to apply smooth thin films. Finally, several powder colors can be applied before curing them all together, allowing color blending and bleed special effects in a single layer. Because no carrier fluid evaporates away, the coating process emits few volatile organic compounds (VOC). Properties of powder coating Powder coated bicycle frames and partsīecause powder coating does not have a liquid carrier, it can produce thicker coatings than conventional liquid coatings without running or sagging, and powder coating produces minimal appearance differences between horizontally coated surfaces and vertically coated surfaces. The process is useful for coatings on metal used in many household appliances, aluminum products and automotive parts. The finish is harder and tougher than conventional paint. This process puts a coating on an item electrostatically, which is then cured by heat. The powder coating process was invented around 1945 by Daniel Gustin and received US Patent 2538562 in 1945. Advancements in powder coating technology like UV-curable powder coatings allow for other materials such as plastics, composites, carbon fiber, and MDF ( medium-density fibreboard) to be powder coated due to the minimum heat and oven dwell time required to process these components. Powder coating is mainly used for coating of metals, such as household appliances, aluminium extrusions, drum hardware, automobiles, and bicycle frames. It is usually used to create a hard finish that is tougher than conventional paint. The powder may be a thermoplastic or a thermoset polymer. Unlike conventional liquid paint which is delivered via an evaporating solvent, powder coating is typically applied electrostatically and then cured under heat or with ultraviolet light. Powder coating is a type of coating that is applied as a free-flowing, dry powder. Type of coating applied as a free-flowing, dry powder Heat-sensitive carbon fiber tubes coated with a UV curable powder coating.
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