Powder coatings have experienced a rapid growth throughout the world due to its enhanced technology, their superior decorative and functional properties and unsurpassed cost efficiency.  The use of powder coatings have been steadily gaining acceptance over traditional wet paint and other finishing techniques in light of technological advances made in the past decade.  It has developed to be the most easily applied, economical and durable finish for almost every metal product.

What is Powder Coating?:               

Powder coating is a simple 3-stage process:

1. Pretreatment of metal

2. Powder application by either electrostatic or friction-charging (tribostatic) with full recovery,

3. Curing.  The coating can be done either manually or automatically, both with large production capacity and minimum labor requirement.

What are the Advantages of Powder Coating?:                

First of all, powder coatings are ideal for ferrous and non-ferrous metal requiring a protective and decorative finish.  Typical examples are domestic appliances, motor car accessories, exterior and interior architectural metal work, machine tools, etc.

Secondly, Corro-Coat powder coatings give a 100% solid coating in one operation with no costly and wasteful by-products, very low fire hazards and causes little or no danger to health in correctly installed and maintained application plants and equipment.

Thirdly,  powder coating wastes less energy,  Taking automation and oven efficiency into account, powder coating require up to 50% less energy in the total system compared to solvent based systems.  Also, powder coating ensures the application of a top quality protective film in one operation.  Traditional methods require multiple operations to build up a coating giving the same protection.   Another advantage is that powder coating process is easily automated to meet high production volumes.  It can also be done by a simple manual system for lower production volumes.

Electrostatic Charging:                    

A high, usually negative, voltage of 40-100kV causes a large number of electrons to attach to the powder particles.  In addition to this build up of charge on the particles, a large number of electrons are carried through the air, causing the object to receive considerable more charge than is transferred through the powder itself.

Tribostatic charging (also called friction charging):                    

By increasing the flow speed and constricting the spray tube bore of the gun, the powder particles are charged by being rubbed against the hose wall.  Thus, between the spray gun and the object, no powerful electric fields and lines of force develop.   This makes it possible to achieve good powder penetration into otherwise inaccessible areas.  By being less dependent on spray distance and the geometry of the components, the Tribostatic method often secures a more uniform coat thickness.

Corro-Coat, Inc manufactures tailor-made products in all quantities for Tribostatic charging.  Some powder types however are not well suited for the purpose, among them dry-mixed metallic effect powders.  Due to the very fine, diffuse cloud of powder, it is often necessary to use several spray guns to achieve the same capacity as with conventional charging.

Powder Coating by Manual Application:                

Powder coating is done by a small handgun, ideal for smaller components and mixed goods.  Pre-treatment can be done - as shown- by blast cleaning or any other method suited for the finished product.  Curing takes place in a box oven.

Automatic Powder Application:                    

Powder coating line with one booth, typical equipment used on large series in one color.

Pre-treatment is either iron or zinc phosphating.  The curing takes place in a U-TURN oven.  The coating line is equipped with the Jotun Powder Coatings "Big Bag' system.

Powder Coating Line with DIP-Pre-treatment:                

The coating line is equipped with two moveable spray-booths.  Allows easy and fast color changes.  Curing is done in tunnel oven.  Pre-treatment by dip immersion; chromating and/or phosphating process is usually employed.  Typical coating line when coating long items, i.e. extrusions or larger sheets.

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