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How Spray Paint Works


Industrial Applications of Spray Paint
Spray paint definitely comes in handy in the auto industry.
Spray paint definitely comes in handy in the auto industry.
Jupiterimages/┬ęGetty Images/Thinkstock

The benefits spray paint offers weekend warriors -- fast application, even coating, little waste -- are magnified in a large-scale setting, and it wasn't long after Seymour launched his idea to the masses that factories and manufacturing plants started to take notice.

Powder coating, vacuum coating and flatline spraying are the three most common methods for industrial spray painting.

Powder coating, sometimes referred to as electrostatic spray painting, is a method for applying dry paint to a surface. Like the paint-propellant mixture inside a spray can, compressed air is used to drive atomized particles of paint through a spray gun onto the target. These particles are very fine and resemble dust, or a powder. And just as with the aerosol can, the particles acquire an electrical charge from the friction created as they pass through the spray nozzle. Because positively charged particles repel each other, they distribute themselves evenly before they make contact with the object being painted. Since the object is always oppositely charged, usually by being grounded using a cable attached to any metal part of the assembly, the paint adheres to the surface.

Companies turn to vacuum coating to apply water-based paint to objects (usually pieces manufactured in sheets such as wood, glass or plastics) that require extremely thin coats. In this method, the object being painted is placed into a chamber, or paint reservoir, where its entire surface area is either submerged into a paint solution or sprayed with a nozzle. The paint is applied in the same volume uniformly around the object, so the entire piece is covered. Finally, the object is removed from the chamber and exposed to extremely high levels of UV light. This photochemical process, called UV curing, uses light rather than heat and is capable of drying objects in seconds.

Finally, flatline spraying is among the most popular methods for painting material that's manufactured in large quantities. Objects, usually small items less than 4 inches (about 10 centimeters) thick, on an assembly line are fed into a machine designed specifically for that part. The paint is applied by spray guns programmed to complete a series of movements to ensure the entire piece is covered.

But spray paint isn't all home improvement and manufacturing. Keep reading to find out how spray paint is making women and decaying buildings more attractive.