| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2005: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2004: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2003: ¥1,900,000 (Direct Cost: ¥1,900,000)
|
|---|
| Research Abstract |
Electrostatic powder coating is one of the promising technologies for pollution-free coatings. The electrostatic powder coating has two major types, corona charging and tribocharging. The surface smoothness is not sufficient in the corona charging type electrostatic powder coating. On the other hand, the tribocharging electrostatic powder coating produces smooth coating layers, but available coating powders are limited by the triboelectric series. The research project aimed to clear the limitation for coating powders by using charge control agents for both the tribocharging spray gun and the coating powders.
First, a positive type charge control agent or a negative type charge control agent was incorporated into Nylon and polyethylene tubes, which were used for coating powder charging instead of a spray gun, and the change in charging ability was examined. A barium oxide powder or molybdenum oxide powder were also incorporated into the both tubes, that are more heat resistive than the c
… More
harge control agents. The concentration of the charge control agents and metal oxide powders were changed from 0 to 5 wt%.
The ionization potentials of the both tubes were changed associated with incorporation of the charge control agents or metal oxide powders, which modified the charging characteristics of polymers. However, some of the tubes incorporated with the charge control agents or metal oxide powders did not show sufficient change in charging characteristics. This result can be attributable to the fact that some incorporated powders existed in the bulk of the tube, not at the surface. Tribocharging characteristics of coating powders made of acrylic, epoxy, polyester polymers with the modified tubes were investigated by using a suction type Faraday cage. The tribocharge Q/M of the coating powders depended on the type of polymers somewhat. Some coating powders tribocharged to a high level, 1 to 2 μC/g, while, other powders tribocharged at low level, about 0.5 μC/g.
Next, the charge control agents were incorporated into the coating powders, and the tribocharging characteristics were examined. It is concluded that the charging characteristics can be controlled by using charge control agents into the coating powders, however, the trap depth of the coating powders does not change by the charge control agents. Less
|
