Unipolarity powder coating systems including improved tribocharging and corona guns
AssigneeNordson Corporation
InventorsWilliam R. Rehman, Harry J. Lader, James W. Messerly
Life of this patent
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Abstract
A plurality of unconventional negative tribo-charging materials are described for use as the powder contact surfaces in tribocharging and corona powder spray guns, gun components, and powder delivery system components. The invention also provides a short barrel tribo-charging powder spray gun having an interchangeable powder contact insert and nozzle, with turbulence inducing air jets. The invention further provides novel tribocharging and corona gun designs. Improved powder coating systems are made possible wherein, for example, negative tribo guns can be utilized with negative corona guns to coat different parts of the same workpiece in a powder coating system.
Claims30
An apparatus for spraying powder coating material having a powder flow path, wherein said powder flow path has a charging surface for triboelectrically charging powder coating material which comes in contact with said charging surface, said charging surface comprising a negative tribocharging material selected from polyamide resin blends, fiber reinforced polyamides, aminoplastic resins and acetal polymers.
An apparatus for spraying powder coating material having a powder flow path, wherein said powder flow path having a charging surface for triboelectrically charging powder coating material which comes in contact with said charging surface, further comprising one or more air passages formed through said charging surface, said air passages being in a fluid communication with a source of compressed air.
An apparatus for spraying powder coating material having a powder flow path through which said powder coating material flows, wherein said powder flow path has a first charging surface for triboelectrically charging powder coating material which comes in contact with said first charging surface, said first charging surface comprising a tribocharging material having a first charging polarity, said apparatus further comprising a component through which said powder coating material also flows, said component having a second charging surface which also comprises a tribocharging material having said first charging polarity.
A system for applying powder coating materials to articles, said system including a powder feed apparatus for supplying powder coating material and an apparatus for spraying powder coating material received from said feed apparatus, said spraying apparatus having an electrode for charging said powder coating material a first charging polarity, said feed apparatus including a component having a charging surface for triboelectrically charging powder coating material which comes in contact with said charging surface, said charging surface being comprised of a tribocharging material having said first charging polarity.
A system for applying powder coating materials to articles, said system including at least one corona charging spraying apparatus and at least one tribocharging spraying apparatus, said corona charging spraying apparatus having an electrode for charging said powder coating material a first charging polarity, said tribocharging spraying apparatus having a powder flow path, wherein said powder flow path has a charging surface for triboelectrically charging powder coating material which comes in contact with said charging surface, said powder coating material being charged to said first polarity by said charging surface of said tribocharging spraying apparatus.
A tribocharging powder spraying apparatus, said apparatus including a body having an internal bore, a wear tube being located within said internal bore, an open passageway being provided between said internal bore and said wear tube, at least one air jet passageway being provided through said wear tube, said air jet passageway providing fluid communication between said open passageway and the interior of said wear tube, said wear tube having a charging surface for triboelectrically charging powder coating material which comes in contact with said charging surface, said open passageway being in a fluid communication with a source of compressed air, whereby compressed air flows from said open passageway through said air jet passageway into the interior of said wear tube to affect the flow of powder coating material through said wear tube.
A system for applying powder coating materials to articles, said system including a powder feed apparatus for supplying powder coating material and an apparatus for spraying powder coating material received from said feed apparatus, said feed apparatus including a component having a charging surface for triboelectrically charging powder coating material which comes in contact with said charging surface, said component charging surface being comprised of a negative tribocharging material selected from polyamide resin blends, reinforced polyamides, aminoplastic resins and acetal polymers.
Dependencies are inferred from the claim text.