US3853580A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods for electrogasdynamic coating
Assignee: Energy Innovations Inc
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Filing: 1972-04-18
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Granted: 1974-12-10
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Expires: 1992-04-18
Abstract
Abstract Method for applying coating materials to articles, using electrogasdynamic apparatus providing a flow channel having a dielectric boundary which has a length/width ratio of greater than 2.5. Gas containing particulate coating material is ionized to create an electrical discharge field for imparting an electrical charge to the particles prior to passage through the dielectrically bounded flow path and thereby creating a high space charge potential. In special applications, a free-radical forming monomer gas or a fusible particle substance is carried in an inert gas into the electrical discharge field and through the flow channel toward the article to be coated. In any case, the charged particles are subjected to an axial charge repelling field (due to space charge effects) in the flow channel to raise the electrical potential of the particles, and thereby the potential gradient between the particles and the workpiece.
Inventors
- 👤 M Gourdine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:57
CPC Classifications
B; B05; B05B; B05B5/00; B05B5/08; B05B5/001; B05B5/025; B05B5/03; B05B5/032
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
233 words
A METHOD OF APPLYING A FIXED COATING TO A SUBSTRATE, INCLUDING THE STEPS OF: FLOWING A GAS IN A BOUNDED FLOW PATH, INCLUDING IN THE GAS A COATING SUBSTANCE, ESTABLISHING AN IONIZING FIELD BETWEEN AT LEAST TWO ELECTRODES AT AN UPSTREAM LOCATION IN SAID BOUNDED FLOW PATH, THEREBY SUBJECTING THE GAS TO SAID IONIZING FIELD TO PROVIDE CHARGED PARTICLES OF THE COATING SUBSTANCE, FORCING THE GAS AND ENTRAINED CHARGED PARTICLES OF THE COATING SUBSTANCE DOWNSTREAM THROUGH A PORTION OF THE BOUNDED FLOW PATH TO AN EXIT FROM THE BOUNDED FLOW PATH, EMITTING THE CHARGED PARTICLES OUT OF THE BOUNDED FLOW PATH BY SAID EXIT TO A LOCATION LESS CONSTRICTED THAN THE BOUNDED FLOW PATH, THEREBY CREATING, IN THE VICINITY OF THE EXIT, A SPACE CHARGE FIELD AT AN ELECTROGASDYNAMICALLY INCREASED POTENTIAL AND SEPARATED FROM THE CHARGING ELECTRODE BY SAID PORTION OF FLOW PATH, CONTINUING TO FORCE GAS ENTRAINED CHARGED PORTICLES THROUGH THE BOUNDED FLOW PATH PORTION AND OUT OF SAID EXIT IN OPPOSITION TO SAID SPACE CHARGE FIELD, AND DISPOSING THE SURFACE OF THE SUBSTRATE TO BE COATED BEYOND SAID EXIT SO AS TO BE CONTACTED BY SAID PARTICLES, SAID STEP OF FORCING THE GAS AND ENTRAINED CHARGED PARTICLES THROUGH A BOUNDED FLOW PARTH PORTION COMPRISING FLOWING THE GAS AND CHARGED PARTICLES ALONG A PATH PORTION SUFFICIENTLY LONG TO PERMIT AN ELECTROGASDYNAMIC POTENTIAL INCREASE TO A VERY HIGH POTENTIAL WITHOUT INCURRING DIELECTRIC BREAKDOWN.
Claim 2
Independent Claim
233 words
A METHOD OF APPLYING A FIXED COATING TO A SUBSTRATE, INCLUDING THE STEPS OF: FLOWING A GAS IN A BOUNDED FLOW PATH, INCLUDING IN THE GAS A COATING SUBSTANCE, ESTABLISHING AN IONIZING FIELD BETWEEN AT LEAST TWO ELECTRODES AT AN UPSTREAM LOCATION IN SAID BOUNDED FLOW PATH, THEREBY SUBJECTING THE GAS TO SAID IONIZING FIELD TO PROVIDE CHARGED PARTICLES OF THE COATING SUBSTANCE, FORCING THE GAS AND ENTRAINED CHARGED PARTICLES OF THE COATING SUBSTANCE DOWNSTREAM THROUGH A PORTION OF THE BOUNDED FLOW PATH TO AN EXIT FROM THE BOUNDED FLOW PATH, EMITTING THE CHARGED PARTICLES OUT OF THE BOUNDED FLOW PATH BY SAID EXIT TO A LOCATION LESS CONSTRICTED THAN THE BOUNDED FLOW PATH, THEREBY CREATING, IN THE VICINITY OF THE EXIT, A SPACE CHARGE FIELD AT AN ELECTROGASDYNAMICALLY INCREASED POTENTIAL AND SEPARATED FROM THE CHARGING ELECTRODE BY SAID PORTION OF FLOW PATH, CONTINUING TO FORCE GAS ENTRAINED CHARGED PORTICLES THROUGH THE BOUNDED FLOW PATH PORTION AND OUT OF SAID EXIT IN OPPOSITION TO SAID SPACE CHARGE FIELD, AND DISPOSING THE SURFACE OF THE SUBSTRATE TO BE COATED BEYOND SAID EXIT SO AS TO BE CONTACTED BY SAID PARTICLES, SAID STEP OF FORCING THE GAS AND ENTRAINED CHARGED PARTICLES THROUGH A BOUNDED FLOW PARTH PORTION COMPRISING FLOWING THE GAS AND CHARGED PARTICLES ALONG A PATH PORTION SUFFICIENTLY LONG TO PERMIT AN ELECTROGASDYNAMIC POTENTIAL INCREASE TO A VERY HIGH POTENTIAL WITHOUT INCURRING DIELECTRIC BREAKDOWN.
Claim 3
Dependent Claim
31 words
A method as defined in claim 1, in which: the substrate to be coated is the inside surface of a conduit, and the flow path is located interiorly of the conduit.
Claim 4
Dependent Claim
24 words
A method as defined in claim 2, in which: the axis of the flow path is substantially parallel to the axis of the conduit.
Claim 5
Dependent Claim
39 words
A method as defined in claim 1 further comprising the step of: providing the substrate with a reference potential different from the space charge potential to thereby create a mutual electrical force between the substrate and the charged particles.
Claim 6
Dependent Claim
38 words
A method as set forth in claim 4, wherein: the substrate to be coated is an object of a dielectric material, and the reference potential is provided interiorly of the object relative to the surface to be coated.
Claim 7
Dependent Claim
24 words
A method as defined in claim 5, wherein: the substrate to be coated is located within a chamber having walls at said reference potential.
Claim 8
Dependent Claim
52 words
A method in accordance with claim 1, in which: the bounded flow path has an aspect ratio of length L to width W of at least 2.5 where width W is taken as the maximum cross-sectional dimension of the channel normal to the direction of flow at the maximum space charge concentration.
Claim 9
Dependent Claim
55 words
A method according to claim 1, further comprising the steps of: flowing a monomer gas with the ionizable gas down the flow path; and depositing on the substrate free radical material and partculate matter, whereby the free radical material polymerizes to form a mixed coating of the particulate matter and the polymer of the monomer.
Claim 10
Dependent Claim
42 words
A method as recited in claim 1, further comprising the steps of: adding heat to the particles carried by the gas prior to contact with the substrate to be coated, thereby to condition the particles for fusion upon contact with the substrate.
Claim 11
Dependent Claim
26 words
A method as recited in claim 1, further comprising the step of: applying heat to the substrate, thereby to fuse together the particles contacting the surface.
Claim 12
Dependent Claim
67 words
A method as recited in claim 1, wherein the substrate to be coated is elongate and substantially flat, the method further comprising the steps of: moving the flat substrate in the direction of its elongation to thereby subject the substrate to continuous coating by the particulate coating substance; and stripping the coating from the substrate to thereby form a continuous sheet of the substance forming the particles.
Claim 13
Independent Claim
115 words
A method of coating the surface of a substrate with a substance initially in the form of a monomer gas, comprising the steps of: flowing the monomer gas to an electrical discharge field in the flow path to thereby form charged and uncharged free radical matter of the monomer, flowing and emitting primarily only the uncharged of the free radical matter through the flow path and out the exit to a less constricted location, restraining substantially all of the charged radical matter from flowing through the flow path and the exit by field opposItion, and disposing the surface of the substrate beyond said outlet to be contacted and coated by the uncharged free radical matter.
Claim 14
Independent Claim
115 words
A method of coating the surface of a substrate with a substance initially in the form of a monomer gas, comprising the steps of: flowing the monomer gas to an electrical discharge field in the flow path to thereby form charged and uncharged free radical matter of the monomer, flowing and emitting primarily only the uncharged of the free radical matter through the flow path and out the exit to a less constricted location, restraining substantially all of the charged radical matter from flowing through the flow path and the exit by field opposItion, and disposing the surface of the substrate beyond said outlet to be contacted and coated by the uncharged free radical matter.
Claim 15
Independent Claim
346 words
A method of coating first particles with a substance initially in the form of second particles, comprising the steps of: providing first and second bounded flow paths having, first and second exits, respectively, establishing a first ionizing field between at least two electrodes at an upstream location in the first bounded flow path, establishing a second ionizing field between at least two electrodes at an upstream location in the second bounded flow path, flowing a gas in the first path and including the first particles therein, flowing a gas in the second path and including the second particles therein, subjecting the gas and first particles in the first flow path to the first ionizing field therein to thereby impart charges of one polarity to the first particles, subjecting the gas and second particles in the second flow path to the second ionizing field therein to thereby impart charges of an opposite polarity from said one polarity to the second particles, forcing the gas and entrained charged first and second particles downstream through a portion of the respective first and second bounded flow paths to respective exits, emitting the charged particles out of the bounded flow paths by said exits to a location less constricted than the bounded flow paths, thereby creating, in the vicinity of each exit, a space charge field at electrogasdynamically increased potential and separated from the respective charging electrodes of the associated flow path by said portion of the associated flow path, continuing to force gas entrained first and second charged particles through the bounded flow path portions out of said exits in opposition to said space charge fields, and admixing the first and second particles outside of their respective paths to thereby effect the combination of the particles bearing opposite charges due to the mutual electrical forces therebetween, said steps of forcing the gas and entrained charged particles through a bounded flow path portion comprising flowing the gas and charged particles along respective path portions sufficiently long to permit an electrogasdynamic potential increase to a very high potential without incurring dielectric breakdown.
Claim 16
Independent Claim
346 words
A method of coating first particles with a substance initially in the form of second particles, comprising the steps of: providing first and second bounded flow paths having, first and second exits, respectively, establishing a first ionizing field between at least two electrodes at an upstream location in the first bounded flow path, establishing a second ionizing field between at least two electrodes at an upstream location in the second bounded flow path, flowing a gas in the first path and including the first particles therein, flowing a gas in the second path and including the second particles therein, subjecting the gas and first particles in the first flow path to the first ionizing field therein to thereby impart charges of one polarity to the first particles, subjecting the gas and second particles in the second flow path to the second ionizing field therein to thereby impart charges of an opposite polarity from said one polarity to the second particles, forcing the gas and entrained charged first and second particles downstream through a portion of the respective first and second bounded flow paths to respective exits, emitting the charged particles out of the bounded flow paths by said exits to a location less constricted than the bounded flow paths, thereby creating, in the vicinity of each exit, a space charge field at electrogasdynamically increased potential and separated from the respective charging electrodes of the associated flow path by said portion of the associated flow path, continuing to force gas entrained first and second charged particles through the bounded flow path portions out of said exits in opposition to said space charge fields, and admixing the first and second particles outside of their respective paths to thereby effect the combination of the particles bearing opposite charges due to the mutual electrical forces therebetween, said steps of forcing the gas and entrained charged particles through a bounded flow path portion comprising flowing the gas and charged particles along respective path portions sufficiently long to permit an electrogasdynamic potential increase to a very high potential without incurring dielectric breakdown.
Claim 17
Dependent Claim
55 words
A method as defined in claim 13, in which: the charges are imparted to the first and second particles by subjecting them to respective electrical discharge between corona and attractor electrodes, wherein the electrical polarity of each corona electrode corresponds to the polarity of the charge imparted to the particles in the associated flow path.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |