Powder Coatings

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What is powder coating?

A free flowing dry powder
Typically applied electrostatically
Cured under heat to allow the powder to melt and flow to produce a film
Cooled to give a solid decorative and protective film

What are the advantages of powder coatings?

Emit zero to near zero Volatile Organic Compounds (VOC)
Overspray can be recycled to achieve closer to 100% use of the coating
Good transfer efficiency
Great appearance
Durable

What are the types of powder coatings?

Thermosetting – undergoes a chemical reaction during cure improving the performance properties.
Thermoplastic – simply melts and re-solidifies the binding polymer during the film formation and does not undergo a chemical reaction during the baking process but rather flows out into the final coating.

What are the basic components of powder coatings?

Resin and curing agent – components that cure to form a coating film also called the Binder. They provide the powder coatings’ mechanical, chemical and outdoor properties along with corrosion resistance.
Filler – inorganic materials which enhances properties such as abrasion and corrosion resistance and hardness.
Pigments – organic or inorganic material that provides colour to the finished coating.
Additives – often minor components used to tailor specific properties such as flow, gloss or texture.

How is powder produced?

Production stages:

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How is the powder applied?

Electrostatic spray application

Powder particles are charged and attracted to the earthed object which is to be coated.

Corona powder particles are negatively charged

Tribo powder particles are positively charged

Fluidised bed dipping

Compressed air aerates the powder and causes it to behave as a liquid
Preheated item to be coated is dipped
Powder melts on item
Item removed from bed coated
Item cools