Patent EA-004439-B1 (EA)
Title: Atmospheric plasma method for treating sheet electricity conducting and device therefor
Inventor: KOULIK PAVEL
IPC: H05B7/148
Filed: 2001-11-12
Abstract: 1. A process for the treatment with an atmospheric plasma of an object to be treated, made of an electrically conductive material, including: the generation of plasma jets by plasma generators, the application of the plasma jets to a surface of the object to be treated, and the relative displacement of the object to be treated relative to the plasma generators, characterised in that at least one of the plasma jets is a cathodic jet and at least one of the plasma jets is an anodic jet, said anodic jet being applied to a treatment zone on said surface to be treated in the proximity of the cathodic jet. 2. A process according to claim 1, characterised in that an electrical current for the generation of the cathodic and anodic plasma jets is divided into three parts, one, I3, flowing through the object to be treated and the two others, I1, I2, being fed to the anodic and cathodic plasma jets. 3. A process according to claim 1 or 2, characterised in that the cathodic jet forms with the surface to be treated an acute angle [alpha]. 4. A process according to claim 1, 2 or 3, characterised in that the anodic jet forms with the surface to be treated, an angle [beta] which is greater than the angle [alpha] formed between the cathodic jet and the surface to be treated. 5. A process according to claim 4, characterised in that the angle [beta] between the anodic jet and the surface to be treated approaches or is substantially equal to 90 degree . 6. A process according to claim 3, 4 or 5, characterised in that the angle [alpha] between the cathodic jet and the surface to be treated is between 25 degree and 60 degree . 7. A process according to one of the preceding claims, characterised in that it includes the generation of a plurality of the anodic and cathodic jets, arranged alternately in a transverse direction with respect to the direction of the motion of the object to be treated relative to the plasma generators. 8. A process according to one of the preceding claims, characterised in that the impulse received by the cathodic jets is more highly powered than that received by the anodic jets. 9. A process according to one of the preceding claims, characterised in that a flow of air or of gas, dragged along by the object to be treated, is separated from the surface to be treated upstream of the treatment zone. 10. A process according to one of the preceding claims, characterised in that a flow of gas dragged by the object to be treated is made laminar, upstream of the treatment zone. 11. A process according to one of the preceding claims, characterised in that the plasma jets are oriented at an acute angle [gamma] with respect to the direction of motion v of the object to be treated, relative to the plasma generators. 12. A process according to one of the preceding claims, characterised in that the object to be treated is a foil-shaped. 13. A process according to the preceding claim, characterised in that the plasma jets are positioned on the two sides of the foil. 14. A process according to the preceding claim, characterised in that the plasma jets on one of the sides of the foil are arranged in such a manner as to be offset with respect to the plasma jets on the other side of the foil. 15. A process according to one of the preceding claims, characterised in that the objet to be treated is in the form of a wire. 16. A process according to one of the preceding claims, characterised in that one or several jets of additional gas Q is or are directed onto the plasma jets, in order to widen or compress the plasma jets directed against the object to be treated. 17. A process according to one of the preceding claims, characterised in that an acoustic or an ultrasonic vibration is generated on the object to be treated, during the action of the plasma. 18. A process according to claim 17, characterised in that the acoustic or the ultrasonic vibrations are created by a process of plasma generation through supplied electrical pulses, wherein the duration of the leading edge of the magnitude of the supplied electrical current pulses is sufficiently short to enable the process of increase of the magnitude of the current to be isochoric. 19. A process according to claim 18, characterised in that the frequency of the electrical current pulses is close or equal to the frequency of the acoustic vibrations. 20. A process according to one of the preceding claims, characterised in that an alternating magnetic field is generated in such a manner that the resulting Ampere forces produce a sweeping oscillation of the plasma jets. 21. A process according to the preceding claim, characterised in that the frequency [nu] of the oscillations of the magnetic field is equal to, or greater, than the ratio of the relative speed of motion of the object to be treated to the diameter of the plasma jets. 22. A device for carrying out the process according to one of the preceding claims, characterised in that it includes at least one cathodic plasma jet generator and at least one anodic plasma jet generator, arranged in such a manner that the anodic jet is applied to a treatment zone of the surface to be treated, in the proximity of the cathodic jet. 23. A device according to claim 22, characterised in that it includes an electrical circuit for supplying the plasma jets, a loop of the electrical circuit being closed by a portion of the object to be treated and including a means for varying the electrical current I3 flowing through the object to be treated. 24. A device according to claim 22 or 23, characterised in that the plasma jet generator includes an electrode, a stabilising channel, a nozzle for forming the plasma jet and a supply system which makes it possible to introduce and to control the flow, of the gas protecting the electrode and of the additional gases brought to the plasma jet. 25. A device according to claim 22, 23 or 24, characterised in that the cathodic jet generator is directed on the surface to be treated under an angle [alpha] which is acute. 26. A device according to claim 22, 23, 24 or 25, characterised in that the anodic jet generator is directed to the surface to be treated at an angle [beta] which is greater than the angle [alpha] between the cathodic jet generator and the surface to be treated. 27. A device according to claim 26, characterised in that the angle [beta] between the anodic jet generator and the surface to be treated approaches or is substantially equal to 90 degree . 28. A device according to claim 26 or 25, characterised in that the angle [alpha] between the cathodic jet generator and the surface to be treated is between 25 degree and 60 degree . 29. A device according to one of the claims 22 to 28, characterised in that it includes a plurality of the anodic and cathodic jet generators placed alternately in a transverse direction with respect to the direction of the motion of the object to be treated, relative to the plasma generators. 30. A device according to one of the claims 22 to 29, characterised in that, in the direction which is transverse with respect to the direction of motion v of the object to be treated, the cathodic and the anodic jet generators alternate in such a manner that the axis of each one of the generators of a given polarity is at an equal distance from the axes of the two neighbouring generators, both of the opposite polarity. 31. A device according to claim 29 or 30, characterised in that it includes, at least, two series of plasma jet generators arranged on both sides of the object to be treated, which is in the form of a foil, in such a manner as to treat, simultaneously or sequentially, the two faces of this foil. 32. A device according to one of claims 22 to 31, characterised in that it includes, upstream of the plasma treatment zone, a device for stabilising the air flow. 33. A device according to claim 32, characterised in that the stabilisation device includes a body positioned on each side of the foil to be treated to form a narrow gap for the passage of the foil, and means for introducing additional gases Q into the gap, in order to control and adjust the gas mixture in the plasma treatment zone. 34. A device according to one of claims 22 to 33 for the treatment of foils, characterised in that it includes downstream of the plasma treatment zone, a device for stabilising the air flow including a cooling system. 35. A device according to one of claims 22 to 34, characterised in that it includes aerodynamic bearings arranged, respectively, upstream and downstream of the plasma generators. 36. A device according to claim 35, characterised in that the aerodynamic bearing includes a body with a pressurised air inlet (36), connected via a manifold (37), to outflow orifices (38) directed counter-currently with respect to the motion v of the foil, to create an air cushion between the foil and the body of the bearing. 37. A device according to claim 36, characterised in that the downstream bearings are cooled with water. 38. A device according to claim 36 or 37, characterised in that the outflow orifices have a longitudinal shape and are distributed along the width of the foil, the angle [delta] of the longitudinal direction of the orifices with the direction of motion of the foil being close to 0 degree at the centre of the foil and increasing towards the side edges of the foil. 39. A device according to claim 22, designed for the treatment of wires, characterised in that it includes a plurality of the anodic and cathodic plasma jets generators, arranged along the wire to be treated. 40. A device according to claim 39, characterised in that each series includes several pairs of anodic and of cathodic jet generators arranged substantially symmetrically about the wire to be treated. 41. A device according to claim 39 or claim 40, characterised in that each series is separated from the neighbouring series by a tubular reactor. 42. A device according to claim 41, characterised in that the t