Electrostatics
By: Alexandra Heater
What is it?
Electrostatic spray paint a system used for spray painting metal objects using charged paint particles. The paint is stored in a pressurized container and is released when a valve is pressed down. The paint that is being released of the container comes out in a thin mist, making it easily applied. It is used on metal items because using charged paint is the easiest way to get a consistent and evenly applied layer of paint on the metal object. This system of spray painting was developed by a man with the name of Harold Ransburg in the early 1930's.
Who Uses It
Electrostatic is mostly used by bike frame manufacturers and car manufacturers. These to industries use electrostatic spray paint because this type of paint sticks very well to metal and coats the frames in an even, constant layer of paint. Although electrostatic spray painting can be used for many different painting uses.
How it works
The electrostatic paint system uses charged paint particles to paint metal. By using the "Law of Electrostatics" that opposite particles attract. The paint in the gun is charged at it leaves the gun. The gun is charged by rubbing through the barrel of the gun. This type of charging is called charging by friction. The paint that is charged now leaves the gun with a negative charge. The gun uses compressed air to propel the paint out of the gun. With the paint having a negative charge, the painter wanting the paint to attract to the object they must them give the object a positive charge. Once the object that is desired to be painted is charged positively the painter may begin. Since the paint particles have a negative charge and negative charges repel, they try to get away from each other. With the paint particles spreading out the paint not only covers the front part of the object, but the back part too. This is also how this system sprays a more even coat of paint, making it more efficient than a normal spray painter.
Side Note-The paint can be charged positively or negatively, but for the purpose of my smore we will say that they are negatively charged
Advantages of Electrostatic Spray Painting
As the particles leave the gun they form in a sort of cloud like shape before they coat the object
This is a picture of a electrostatic spray gun
This is a picture of the gun in use
Citations
Google images-search electrostatic paint spray gun
http://home.howstuffworks.com/spray-paint.htm
http://www.ransburgcollection.com/Default.aspx?tabid=66
Youtube- http://www.youtube.com/watch?v=NqcQ6j97vBw