|CONCEPT OF POWDER COATING
The role of powder coating is usually to provide surface protection and secondly to give decorative finish. The economic and environmental pressure to decrease the use and emission of solvents, along with the introduction of increasingly stringent legislation to ensure the strict observation of health and safety regulations, has encouraged the use of powder coating as viable alternatives to solvent based liquid paints.
The technique of electrostatic deposition of charged paint particles was developed and established in 1950, based on principle, whereby paint particles transported by air pressure to the spray head of dispensing gun, receive an electrostatic charge and any grounded or earthen substrate in the path of the projected paint attracts and retain the articles by electrostatic adhesion. This is basic concept of powder coating applications.
Three most commonly used methods of powder charging are,
- Corona method or ionization technique.
- Tribo electric or electrostatic application.
- Air ionizing or triboplus, a combination of both corona and tribo methods.
However, most commonly used is Corona Electrostatic method.