Nordson Corporation

Wordson Corporation

Joseph Rogari

Christopher P Bertellotti

Colin K Drummond

Don Urig

Mark Heckler

An electrostatic powder coating apparatus including a housing with an interior coating area for receiving a workpiece. The interior coating area includes a vortex inducing surface and a pressurized air input device directs air against the surface to form a swirling pattern of air around the workpiece. A powder introducer directs charged powder into the swirling pattern of air and the powder is then electrostatically attracted to the workpiece. The powder introducer may be a powder fluidizing bed disposed in the housing or other suppliers, such as electrostatic powder spray guns. In alternative embodiments, vortex generators in the form of tubular structures connected proximate the housing inlet and outlet have tangential ports for introducing positive pressure air or inducing vacuum in the tubular structures. These also form a swirling pattern of air which may be used to produce or augment the swirling pattern in the coating area or used to collect excess powder while augmenting the coating at the inlet and outlet.

Electrostatic powder coating apparatus using a swirling flow pattern

A method of powder coating a workpiece in a housing having a powder coating area with a workpiece travel path and an interior wall surface sloped around at least a portion of the workpiece travel path includes moving air and powder in the powder coating area along at least a portion of the sloped interior wall surface. As a result, a swirling flow pattern of the air and powder is produced around at least a portion of the workpiece travel path. The workpiece is conveyed along the workpiece travel path, and powder is deposited from the swirling flow pattern onto the workpiece along the portion of the workpiece travel path around which the interior wall slopes.

Electrostatic powder coating method using a swirling flow pattern

An electrostatic fluidized bed powder coating apparatus including powder coating structure, such as a coating enclosure, hood or booth, and a powder fluidizing bed operatively associated with an electrostatic charging device. An enclosed powder accumulator is provided for collecting excess powder from the powder coating structure. A vacuum pump communicates between the powder coating structure and the powder accumulator and is operable by a source of compressed air for forming and controlling a cloud of powder emanating from the fluidizing bed and for transferring excess powder from the powder coating structure to the powder accumulator. In the preferred embodiment, the accumulator includes a cyclone housing. A powder reclaim feeder is disposed below and in communication with the cyclone housing and further communicates with a new powder feeder. A powder conveyor, in the preferred form of a rotating auger, transfers powder from the new powder feeder into the powder reclaim feeder and ultimately transfers the mixed powder into the powder coating structure.

Fluidized bed powder handling and coating apparatus and methods

Annular flow electrostatic powder coater

The electrostatic fluidized bed coating apparatus and system employ a vertically extending gaseous vortex of charged particles. Effects of variations in particle distribution, size, and electrostatic charge strength are minimized by the vertical orientation, enabling the production of coatings of exceptional uniformity. The apparatus is especially suited for construction to simultaneously coat a number of strands of wire or the like.

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Trumbull, CT, United States of America

Joseph Rogari