ELECTROSTATIC COATING METHOD AND ELECTROSTATIC COATING GUN

• US 20130052362A1
• Filed: 05/31/2011
• Published: 02/28/2013
• Est. Priority Date: 05/31/2010
• Status: Active Grant

• Current Assignee: Taikisha Limited
• Original Assignee: Isuzu Motors Limited
• Inventors: Tamura, Yoshinobu
• Granted Patent: US 8,962,095 B2
• Time in Patent Office: Days
• US Class Current: 427/458
• CPC Class Codes: B05B 5/032 for spraying particulate materials
• CPC Class Codes: B05B 5/0426 Means for supplying shaping gas
• CPC Class Codes: B05B 5/0535 at least two electrodes having different potentials being held on the discharge apparatus, one of them being a charging electrode of the corona type located in the spray or close to it, and another being of the non-corona type located outside of the path for the material
• CPC Class Codes: B05D 1/045 on non-conductive substrates
• CPC Class Codes: Y02P 60/21 Dinitrogen oxide [N2O], e.g. using aquaponics, hydroponics or efficiency measures

Abstract

A low conductivity is provided to a coating surface 21 of a non-conductive coating target 20, and the coating surface 21 is coated with a charged paint while free ions are suppressed.

Claims

1. An electrostatic coating method for a coating surface having a low conductivity, comprising:

coating the coating surface with a negatively charged paint while suppressing free ions.

2. The electrostatic coating method according to claim 1, wherein

the paint is negatively charged by a corona discharge from a discharge electrode, and

free ions generated by the corona discharge are reduced or removed by a free ion-removing electrode disposed near the discharge electrode.

3. The electrostatic coating method according to claim 1, wherein

the paint is a conductive paint, and

the conductive paint is negatively charged by receiving direct application of a high voltage from a high-voltage electrode to suppress generation of free ions.

4. The electrostatic coating method according to claim 1, wherein

a low conductivity is provided to a coating surface of a non-conductive coating target by at least one of:

an antistatic treatment on the coating surface; and

grounding of the coating target and use of a conductive paint.

5. The electrostatic coating method according to claim 1, wherein

a low conductivity is provided to a coating surface of a non-conductive coating target by an antistatic treatment of coating the coating surface with an antistatic solution by a wipe application.

6. An electrostatic coating gun comprising:

a paint supply duct configured to pass a conductive paint therethrough;

a high-voltage electrode provided in the paint supply duct, and configured to directly apply a high voltage to the conductive paint passing through the paint supply duct to negatively charge the conductive paint; and

an ejection port provided at a tip end of the paint supply duct, and configured to eject the negatively charged conductive paint to outside.