What is Powder Coating?
 
Powder coating is similar to paint but has some big differences to its application as well as the finished product. Powder coating is applied as a free-flowing dry powder instead of a liquid and it utilises an innovative electrostatic spray gun process. This electrostatic process works in a very similar way to magnetism with positive being attracted to negative etc. The powder becomes electrostatically charged up by the spray gun and is released as a fine spray of electrostatically charged particles. These particles are attracted to the metal item which has an electrode attached. This works by pulling the positively electro-charged particles to the whole of the negatively charged metal item and ensures all of the area is covered with the powder coat. This innovative method works very efficiently and can be seen visibly pulling the electro-charged powder coating from the air surrounding. The powder spray will even cover the sides of the item when being sprayed from the front. This gives many benefits and helps with a deatiled, even cover and a perfect finish.
 
Another big difference between a conventional liquid paint and 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 dry utilising its electrostatic method and is then cured under heat to allow it to flow and form a "skin". The “skin” once set leaves a very hard wearing, extremely durable coating that will last for many years. As with any paint or powder coated item its durability is down to conditions such as being exposed to bad weather, water, salt, chemicals, U.V light and after care. If its durability were to be compared to paint in general, it will always last a lot longer. In general items that have been coated for external use with the correct powder coating will have 20 years+ durability and usually last longer for indoor applications.
Please look at the video below of the metal being coated after it has been heated to the correct temperature in the oven.
 
 
 

The 2 main types of powder coating used in the industry are thermoplastic or thermoset polymer. The thermosets incorporate a cross-linker into the powdered polymer composition and once baked in an oven it will polymerize and cure to form a very tough durable skin. This process is irreversible whereas thermoplastics can be reheated and reset, left over coating can be recycled. Thermoplastics do not have any chemical reactions in the curing process they simply flow melt and set creating the final coating.  Thermoplastics are not commonly used in powder coating applications as they do not adhere to the metal surface like thermosets do. Thermosets are much more widely used in many applications as they adhere to surfaces extremely well leaving a more permanent coat. When the polymer powder is baked it reacts with other chemical groups in the powders composition and polymerize. This improves the curing process and gives the unique final coat amazing performance properties. The most common polymer powders used are polyester, polyurethane, polyester-epoxy (known as hybrid), straight epoxy (fusion bonded epoxy) and acrylics.
Please look at the video below at some architectural steel that has been coated and is about to be oven baked at a specific temperature.
 
Because of its tough setting finish that is tougher than conventional paint it is widely used and is quoted as the “industry standard”. This industrial standard coating is used on many household and industrial items. Amongst the many applications for powder coating there are household appliances; Fridges, Freezers, Washing Machines, Dish Washers, Radiators and a lot more. A lot of aluminium extrusions; Bicycle frames, Hand rails, Stereo equipment, even chair and table frames. There are so many items around the house that are powder coated and you simply just don’t realise, even drum hardware, automobile and bicycle parts. 
 

Powder Coating versus Spray Paint

Because 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 and vertically coated surfaces. The attributes which give powder coating this even coating capability are due to its electrostatic properties. This amongst other reasons like durability is the reason why powder coating is the industries choice!
From an environmentally friendly point, powder coating is the best choice and is more widely used than conventional coating methods especially on projects such as large constructions. Since no carrier fluid evaporates away, the coating process emits very few volatile organic compounds (VOC). Many standard professional-grade spray paints contain Volatile Organic Compounds (VOC). VOC’s are emitted as gases from certain solids or liquids and include a variety of chemicals, some of which may have short- and long-term adverse health effects. VOC’s are emitted by a wide array of products including paints, lacquers and paint strippers.
 

The Final Product

The finished product is a high quality coated item that is highly resistant to abrasion and corrosion and make it ideal for heavy-duty conditions.
The finished coat commonly comes in matte, satin and high gloss. There are also polished chrome, metallic and a clear coating. There are various special effects that can be achieved too.
This process cannot be done at home and should be left to a professional to do. There are many things to take into consideration like pre-treatments; shot blasting, cleaning, priming, and of course which powder should be used. There are various powders for various applications and they are manufactured not just for desired colours and effects but to overcome certain problems. A good example of this would be the pre-treatment galvanization, whereas anything galvanized should be coated with an anti-gassing powder coating. Gasses are emitted from galvanized items in the heating/ curing stage. If anti-gassing polymer powder is not used then the gasses will create bubbles and blisters in the final coating, an effect I am sure nobody wants. Only professionals should be left to handle the application process such as the company linked to this website who are experienced and very reliable for such work.
 

Please take a look at our Aftercare & Maintenance page for more knowledge on how to treat and take care of your product!
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