Electrostatic Spray Coating for Electrostatic Sensitive Solids
Electrostatic spray coating is a highly specialized process which is used to coat metallic surfaces to improve their conductivity, reduce the risk of damage from electrostatic discharges and to increase the life expectancy of the coating. The electrostatic spray coating of various metals is an advanced concept that has emerged due to recent technological advancements. It provides comprehensive coverage of all the relevant aspects of the manufacturing and usage of electro-charged droplets. Early chapters mainly deal with the manufacture and manipulation of electrostatic charged surfaces.
The concept of electrostatic spray coating of metallic surfaces was conceived when there was a need for an improved and more durable coating for use in electronic circuits. This was necessary because of high wear and tear conditions that were to be encountered in the circuits that were located near susceptible metal components such as switches, power supplies and other connective parts. Electrostatic discharges occur when the electric field that is created by the flow of current near the component generates an electric field that is equal to or much stronger than the charge that is present on the surface. When this happens, an electrostatic charge is generated which causes the metal component to develop a slight charge imbalance and this can cause extensive damage.
One of the most common metals that are subjected to electrostatic spraying are those that are sensitive to high levels of electricity. Examples of sensitive metals that can be treated with electrostatic spray coating are copper, brass and aluminum. These materials can be galvanized as well but galvanized components are usually electrostatic resistant and this can reduce the application effectiveness of electrostatic spraying. It is for this reason that electrostatic spraying of these materials is normally limited to small surface areas.
There are several reasons why electrostatic spraying of liquids is preferred over electrostatic generation of charge in the conductive media. Electrostatic spraying allows a much lower level of damage to take place. Spray coating is also a much easier process that has a much lower level of risk involved. The spray coating can also last a very long time without exposing the material to any potential threats that can act as a catalyst to corrosion or affect the electrostatic stability of the coating.
One major disadvantage of electrostatic spray coating is that there is some loss of current in the area around the charged object when the coating has been applied. However, even in this case the relative strength of the electrostatic charge will be far less than that of galvanized components. This makes the coating effective only where there is a low enough level of electrostatic generation to allow for the generation of sufficient charge in the area of application. Therefore, objects that do not generate enough electrostatic charge and are situated close to an active electrostatic generator would be better suited for electrostatic spray coating.
This type of electrostatic generation can often be prevented by using suitable materials that reduce the overall transfer of electrostatic charge. It is generally agreed that plastic materials are among the safest to use around objects that generate electrostatic energy. This is because plastic is so light in weight that it is often impossible to bring it to rest by applying a great amount of pressure on it. This also means that the plastic can simply be moved rather than placed into an area where it might actually rupture. Therefore, it is important to purchase plastic sheeting that is designed specifically for the electrostatic generation around objects that are sensitive to electrostatic charges.
Polystyrene is often used for electrostatic generation around objects such as wires and cables that are susceptible to static build up. When electrostatic charge builds up in these materials, the liquid that is usually dispersed by the surface electrolysis process is water. It is important to remember that the application of electrostatic spray coating must always be directly aimed at the electrostatic generation areas of the materials being coated. If any liquid is sprinkled onto an object and then washed away after it has been electrostatically charged by the electrostatic spray coating, there is a chance that some of it will be left behind in the location of the electrostatic generation device and therefore contaminate other surfaces within the room. Therefore, care must be taken when spraying polystyrene or similar materials because if too much liquid is sprayed onto a surface and then washed away, the surface will become coated with a coating of non-liquid and will not serve any useful purpose for the Electrostatic Spraying of Liquids or Electrostatic Discharge of Solids.
The non-chlorinated types of anti-static bags which are now available contain an organic base that is capable of neutralizing the electrical charge that accumulates over time due to electrostatic attraction and repulsion. The organic base can either be oil or a liquid. The liquids form a protective layer that prevents the liquids from coming in direct contact with the electrostatic wiring. These bags have proven to be highly effective in dealing with electrostatic generation devices such as electrostatic sensitive computer parts. It is also very useful in damping down the power level of appliances and other electronic equipment.