Contrary to liquid coatings, powder coatings
are processed as solids before
being melted in the baking oven to form films. They don't need solvent to keep binder
and filler parts in a liquid suspension form.
From an environmental perspective, powder coatings are an alternative to solvent
based paint. In fact as there is no solvent, the application of powder
almost no emissions.
Moreover, from a performance perspective, powder coatings have been shown to possess
significant durability and resistance to abrasion, corrosion, scratching, and chemicals
when compared to liquid coatings.
Powder Coating Process:
Before coating, the parts to be coated are first pretreated similarly to conventional
liquid coated parts. The pretreatment process is normally conducted in series with
the coating and curing operations.
Powder coatings are applied by two common ways:
- by electrostatic spray (powder is applied with an electrostatic spray gun to a part
that is at earth (or ground) potential)
- by fluidized-bed powder coating.(fluidized coatings allow to coat the substrate
which has been heated to above the melting temperature of the powder coating.)
Powder coatings can be used in a wide range of applications such as automotive,
building, construction, electronic... They offer excellent properties and many economic
and environmental advantages compared to traditional solvent based paints.