Abstract
This experimental study investigated the influences of two different powder systems (coarse and ultrafine) on particle charging and deposition characteristics during electrostatic powder coating processes. Results disclosed that, despite their differences in particle sizes, the two powders behave similarly in deposition process, commonly resulting in a cone-shaped deposited pattern in the inner portion of the substrate and an increase of deposited particles in the fringe region. However, their different properties lead to the discrepancies in their deposition efficiencies, which account for a higher efficiency with the coarse powder. The study further revealed that the coarse powder is superior to the ultrafine powder in charging in-flight particles, which directly contributes to its higher deposition efficiencies. Furthermore, it was disclosed that the two powders exhibit distinct characteristics in charging deposited particles. Compared to the coarse powder, the ultrafine powder is more uniform in charging deposited particles, mainly owing to its greater particle number and higher specific surface area but less mass. In particular, the charging efficiency of overall deposited particles decreases for the ultrafine powder but increases for the coarse powder with increased charging voltage, closely related to their particle properties. However, both powders decrease in charging efficiency of deposited particles with extended spraying duration due to back corona intensifying with spraying.
Original language | English |
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Pages (from-to) | 663-671 |
Number of pages | 9 |
Journal | Journal of Electrostatics |
Volume | 67 |
Issue number | 4 |
DOIs | |
Publication status | Published - Jul 2009 |
Externally published | Yes |
Keywords
- Back corona
- Charge-to-mass ratio
- Corona charging
- Corona quenching
- Electrostatics
- Mass-to-surface ratio
- Particle charging and deposition
- Particle size
- Powder coating
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Biotechnology
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Electrical and Electronic Engineering