Patent EA-001315-B1 (EA)
Title: Method for painting elements of dielectric or low-conductivity material, apparatus and electrode therefor
Inventor: LEBIODA ROBERT
IPC: B05D1/04
Filed: 1996-04-11
Abstract: 1. An electrode (17) in an apparatus for an electrostatic painting of elements made of dielectric or low conducting material for engaging an element to (16) be painted and for connecting to one of the poles of an power source (19), completing the apparatus, said apparatus comprises a paint spraying unit (13) including an electrode in a zone of the paint projection connected to the other pole of the power source (19), said paint spraying unit (13) serving to electrically charge the paint and spray it onto the element to be painted, characterized in that the electrode, on its external surface, having angular regions connected to each other by recess regions, said angular regions engaging at least partially the element to be painted, said angular regions where a peak electrostatic effect is obtained and this peak electrostatic effect causes a substantial deformation of the field lines which enables simultaneous paint particles to be deposited on several sides of the element (16) without paint spraying unit (13) being moved. 2. An electrode (17) according to claim 1, the angular regions (22, 23, 24, 25, 33) being created by protrusions. 3. An electrode (17) according to claim 2 having a core with the protrusions (22, 23, 24, 25, 33) located on its external surface. 4. An electrode (17) according to claim 3, each protrusion (33) being longitudinal and parallel to the electrode axis. 5. An electrode (17) according to any one of claims 2 to 4 having a longiform core whose cross section is circular, with the protrusions (22, 23, 24, 25) forming an helix-shape on fee external surface of the core. 6. An electrode (17) according to claim 5 having a cylindrical core with an external thread and at least one longitudinal groove (26, 27) extending across the thread parallel to the longitudinal direction of the core. 7. An electrode (17) according to claim 1 having a plate-like form with the protrusions being located on at least one of the faces of said plate. 8. An electrode (17) according to claim 1 having a rippled plate-like form. 9. An electrode (17) according to claim 8, the ripples of me plate being triangular. 10. An electrode (17) according to claim 2 or claim 9, the plate having protrusions on at least one of its faces. 11. Method for painting an element (16) of dielectric or low-conductivity material using a paint spraying unit (13) including a chamber connected both to a paint outlet and to a paint supply, including the steps of: mechanically and electrically connecting to the element (16) at least one electrode (17) according to any one of the above claims; creating an electrostatic field between the electrode and the paint spraying unit by applying a potential difference between the electrode and another electrode (17) housed in the chamber of the paint spraying unit (13); feeding the paint from the paint supply (46) towards the paint outlet by passage through the chamber; electrically charging the paint; and spraying said paint onto the member to be painted. 12. Method of painting according to claim 11 using a solid paint in powder form. 13. Method of painting according to claim 11 or claim 12 including the insertion of an electrode (17) inside the member to be painted. 14. Method of painting according to claim 11 or claim 12 including the placement of the electrode (17) on at least one of the external faces of the member be painted. 15. Method of painting according to any one of claims 11 to 14 including sanding the surfaces to be painted before painting. 16. Method according to claim 15 including the application of a sealant to the recesses and edges prior to the projection of the paint. 17. Method of painting according to any one of claims 11 to 16 including passing the paint through a heating chamber (39) in which low flow heating is done at lower speeds of air flow than the subsequent phases of heating. 18. Apparatus for painting members(16) made of dielectric or low-conductivity materials for implementation of the process according to any one of claims 11 to 17 including at least one electrode (17) according to any one of claims 1 to 10. 19. Apparatus according to claim 18 having a heating chamber (39) in which low flow heating is done with lower speeds of air flow than the subsequent phases of heating.