Powder Coating Services & Applications

What Is Powder Coating?
Powder coating is a type of dry coating, which is applied as a free-flowing, dry powder. 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 electro statically and is then cured under heat to allow it to flow and form a "skin." The powder may be a thermoplastic or a thermo set 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 ware, aluminum extrusions, automobile parts, and motorcycle parts. Newer technologies allow other materials, such as MDF, to be powder coated using different methods.

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% use 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 is easily accomplished which would be impossible to achieve with other
   coating processes.

Types of Powder Coatings
There are two main categories of powder coatings: thermosets and thermoplastics. The thermosetting variety incorporates a cross-linker into the formulation. When the powder is baked, it reacts with other chemical groups in the powder polymer and increases the molecular weight and improves the performance properties. The thermoplastic variety does not undergo any additional reactions during the baking process, but rather only flows out into the final coating.

Most Common Polymers:
Polyester • Polyester-Epoxy • Straight Epoxy • Acrylics

Production
The polymer granules are mixed with hardener, pigments and other powder ingredients in a mixer. The mixture is heated in an extruder and the extruded mixture is rolled flat, cooled and broken into small chips. Finally the chips are milled to make a fine powder.

Powder Coating Involves Three Basic Steps:
 • Part Preparation or Pre Treatment
 • The Powder Application
 • The Curing Process