FAQs

This page is  about Frequently Asked Questions  about powder coating. You are invited to add your contributions to this page.

The FAQs about Powder Coating. What Is Powder Coating? Why doesn’t powder coated parts drip or run in the oven? What are Advantages and disadvantages of powder coating Is it hard to learn to powder coat? How much does powder coating cost? Is there any dangers with mobile phones been around powder spray booths? How long does Powder Coating typically last? How many Powder Coat colors are there? How many coats are applied with powder coating? Can powder coatings be applied on site? How are powder coatings manufactured? What is the correct procedure for disposal of powder coatings? The Future of Powder Coating? --------------------------------------------------------- What Is Powder Coating? The powder coating process uses a solvent free dry mix of plastic resins, pigments and fillers that melt and fuse together when heated.  The main difference between a conventional liquid paint and a powder coating is that, the powder coating does not require a solvent to keep the binder and filler parts in a liquid suspension form. The coating is typically applied electrostatically and is then cured under heat to allow it to flow and form a "skin." The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a hard finish that is tougher than conventional paint. Powder coating is mainly used for coating of metals, such as "white goods", aluminium extrusions, and automobile and motorcycle parts. Newer technologies allow other materials, such as MDF (medium-density fibreboard), to be powder coated using different methods. The solid particles of coating are electrostatically charged in a spray gun and carried by low velocity air to the surface of the piece to be coated. The electrostatic charge holds the powder particles in place while the part is cured in a 200 degree C. The heat of the oven causes a chemical reaction to occur and the powder to cure, creating a highly durable finish Back To Top Why doesn’t powder coated parts drip or run in the oven? When powder is in the "gel state" it is very thick like paste and therefore, it doesn’t run or drip. Back To Top What are Advantages and disadvantages of powder coating There are several advantages of powder coating over conventional liquid coatings: Powder coatings emit zero or near zero volatile organic compounds (VOC). Powder coatings can produce much thicker coatings than conventional liquid coatings without running or sagging. Powder coating overspray can be recycled and thus it is possible to achieve nearly 100% utilization of the coating. Powder coating production lines produce less hazardous waste than conventional liquid coatings. Capital equipment and operating costs for a powder line are generally less than for conventional liquid lines. Powder coated items generally have fewer appearance differences between horizontally coated surfaces and vertically coated surfaces than liquid coated items. A wide range of specialty effects are easily accomplished using powder coatings that would be impossible to achieve with other coating processes. Back To Top Is it hard to learn to powder coat? Almost anybody can learn to apply powder with consistent thickness build and minimum waste. One area that is not hard to learn, but often skipped over, is cleaning and preparing the substrate to accept the powder. We spend a lot of time and energy in this area. If you don't get this right, the rest is wasted effort. Put your brain to work here, you'll be glad you did. Back To Top How much does powder coating cost? Powder coating costs about the same as other professionally applied paints or coatings. Some bulk plating processes similar to anodizing may be slightly less expensive. More decorative finishes like chrome plating is substantially more expensive than powder coating. Back To Top Is there any dangers with mobile phones been around powder spray booths? Whilst powder coatings have the advantage over solvent based coatings of having a lower explosion point and therefore is less flammable, caution should always be exercised with any electrical source such as mobile phones. Powder coating is a fine organic dust which in high concentration, in the presence of air and an ignition source such as a mobile phone, could trigger a dust explosion. The concentration of dust required to facilitate a dust explosion is significant, however, it is advisable to keep unnecessary equipment away from the booth and powder store. As a precaution, all mobile phones should be kept clear of these areas. Back To Top How long does Powder Coating typically last? This is a very common question. From the perspective of adhesion and film integrity, correctly applied and pretreated powder coated metal can and has lasted since it was first applied more than 30 years ago. Powder coatings are considered extremely resilient, be a coating of choice for use on gas or oil pipelines which are buried in the earth or underwater. Powder coatings are used on automotive and appliances given their excellent chip resistance, hardness and or chemical resistance. From the perspective of resistance to light and UV degradation, some powder coatings are outstanding, being used on major building such as Duratec and Fluoroset FP. The standard and most common powder coatings are designed for general use and applications. Standard powder coatings offer good weathering resistance, excellent film integrity and very good hardness. Back To Top How many Powder Coat colors are there? There are about 100 different colors on a regular basis, but there are several thousand available . And, if money is no object, there is no limit to what’s available. In addition to the different colors and shades, Powder Coat is available in several “Finish Types”. They are classied as Texture (aka Hammertone), Metallic (like metal flake it comes in several sizes of “Flakes” from large to micro), Solid, Translucent (aka ‘Candy’) and Clear (actually a Clear Translucent). and a fairly new one known as “Chrome”, Back To Top How many coats are applied with powder coating? Powder coatings are generally a one coat finish, applied to suitable cleaned and pretreated substrates. Some coatings, such as metallics, require a clear coat to protect the metallic effect. Back To Top Can powder coatings be applied on site? Powder Coatings are a factory applied finish using specialised equipment. The equipment includes an electrostatic spray gun, spray booth and an oven to bake (or cure) the coating. On site application is not possible given the hot curing cycle required to fuse the coating. Back To Top How are powder coatings manufactured? Powder Coatings are produced by dry blending of resins, pigments, additives and curing agents, which are then extruded at elevated temperatures to melt mix the ingredients. The material then becomes thick and viscous like a honey mixture which is cooled using super chilled water, before the material is crushed progressively to a fine, well defined particle size. Specialised equipment including rotary sieves and particle size measuring equipment is used to monitor and control the particle size distribution. Back To Top What is the correct procedure for disposal of powder coatings? The rules and regulations for powder waste disposal vary across country. In many instances, powder coating is suitable for land fill, however it is important to contact Environmental Protection Agency offices to clarify local requirements for waste disposal. Back To Top The Future of Powder Coating? In addition to successfully penetrating the MDF (medium density fiberboard) market, powder has proven to be an effective finishing choice for other heat sensitive substrates such as plastic parts made of nylon and polycarbonate and assembled or partially assembled products such as appliances, electric motors or automotive radiators. Because of advancements in low temperature cure powders, plastic parts and wires and rubber seals and gaskets are not damaged in the powder coating process. And the revolution has just begun. Successful testing has occurred on hardwoods such as beech, oak, ash and walnut. Research engineers are studying the use of powder on paper-laminated MDF, laminated flooring and particleboard. Research is also being conducted on countertops, wood moulding and trim, all of which will increase demand for, and use of, powder coatings in more new markets Back To Top