The term Epoxy Powder Coating is used frequently as a generic term for the Powder Coating process.
Powder Coating and particularly Epoxy-based Powder Coating became buzz words that everybody used but never really fully understood.
People knew it was to do with ‘painting’ or applying coatings to articles but not much more than that.
This is mainly due to the word Epoxy as it is probably the most commonly known resin type and if you asked someone to name a Resin the answer would most likely be Epoxy as it is a familiar word known in other areas such as glues and adhesives.
Powder Coatings using Epoxy Resin as the base material were the first powder coating powders to be made in the third quarter of the last century.
Epoxy Powders provided a hard, impact resistant coating with very good corrosion & impact resistance as well as good adhesion to the substrate material.
At the time they were a big step forward in the ‘Painting Process’.
Until Powder Coating was introduced painting a metal part usually involved at least two coats of paint and more likely three when a high specification was needed.
Powder Coating enabled ‘One Coat’ finishing, the ability to apply 3 thou or 75 microns of finish in one go, no multiple coats.
No wet paint, no thinners to stove off.
Just one single coat of Epoxy Powder, bake it to 180 degrees centigrade for 12 minutes metal temperature and you had a smooth durable ‘paint type finish’.
It was a huge leap forward in coating efficiency, labour and money saving as well as being green and kinder to the atmosphere.
The only drawback with Epoxy Powders was that when used in exterior situations they would ‘chalk’ and discolour.
This was caused by exposure to ultra violet light.
However it is only important if the parts that you want to protect from corrosion are exposed to ultra violet light.
The advantages of Epoxy Powder Coating are, good hardness; Using ISO 6272-2 as a test they will pass 25 kilogram/cm. This may seem hard to understand without comparisons but it is safe to say that this is considered good when compared to wet paint specifications.
Properly applied onto a clean substrate Epoxy Powder Coating will provide very good adhesion to the surface of the component.
The factor that affects adhesion the most is the cleanliness of the surface of the part.
Unless it is clean and free from Scale, Rust,Grease and Oils then no matter what type of powder you apply the adhesion will be poor.
Parts with rust or scale should be shot or grit blasted. Grease or Oil should be removed by Vapour Degreasing of a Hot Wash Process.
In summary, there is a place for Epoxy Powder Coatings when choosing what finish to specify for your products as long as they are not used outside.