Abstract:
An electrostatic coating product spraying device comprising: at least one sprayer having an electrostatic charging mechanism; and a support structure supporting the at least one sprayer, the structure including elements which are at ground potential, wherein the support structure includes an electrostatic shield positioned and arranged so that the electrostatic charging mechanism is located between the electrostatic shield and an object to be coated. The electrostatic shield is maintained at a potential differing from ground potential.
Abstract:
An electrostatic powder coating apparatus is provided which includes a spray gun and a powder supply unit. The spray gun includes facilities for dually functioning to both pulverize and disperse the aggregated powder and powder adhesion preventing facilities. Both the pulverizing and dispersing facilities and the powder adhesion prevention facilities are provided in a nozzle lip of the spray gun of the electrostatic powder coating apparatus. The powder supply unit includes a temperature/humidity control facilities for adjusting the temperature and humidity of the compressed air supplied to an air chamber within the powder supply unit.
Abstract:
A spray device and method for the coating of objects with powder coating material. A high voltage electrode or several electrodes are located on only one side of the coating material stream in the vicinity of a spray orifice for electrostatically charging the coating material. A first flow of compressed air is directed over the electrodes to keep the coating material from accumulating on the electrode and to shape the envelope of the sprayed coating material. A second stream of compressed air is directed at the stream of coating material to counteract the deflection of the stream by the first flow and by the effects of the high voltage. Better coating efficiency (reduced loss of sprayed powder) is achieved than with electrodes arranged on both sides of the coating material stream.
Abstract:
A conveyor device for applying a high voltage to a work transported in a coating booth includes a conveyor device main body having a running base running in the coating booth and an electrode attachment attached to the running base being insulated therefrom for carrying the work and applying a high voltage to the work, an electromagnetic wave transmitter disposed in the coating booth for transmitting electromagnetic waves to the running base during running in a high voltage application zone and a low voltage generator means for receiving electromagnetic waves from the electromagnetic transmitter means and a high voltage generator for stepping-up a low voltage outputted from the low voltage generator and supplying a high voltage to the electrode attachment, mounted on the running base.
Abstract:
A system and method for coincidence detection of ungrounded or inadequately grounded parts during the electrostatic coating process in order to improve production flow, provide an overall cost saving by efficient use of the coating material and prevention of accidental fires and false shutdown during production. The present invention utilizes a coincidence detection technique which performs a test for radio-frequency electromagnetic energy radiated by sparking and/or corona discharge caused by ungrounded parts outside a electrostatic coating area and a test for sensing and discriminating spurious radio-frequency electromagnetic energy radiated by sparking and/or corona discharge caused by any other external source. In accordance with one specific embodiment, the test performed outside the booth may include a further test for detecting ultraviolet energy radiated by the sparking and/or corona discharge. Upon detecting an ungrounded part, the part may be removed from the production line and appropriate steps to properly ground it may be taken. Performing coincident tests thus prevents false shutdowns in the production line.
Abstract:
A process for improving the electrostatic charge developed on a resin powder composition for electrostatic coating of solid objects and the method of application thereof. The resin powder comprises (i) a thermosetting or thermoplastic resin and (ii) an electrostatic property modifying agent (polyalkylene ether, polyalkylene glycol, polyethoxylated stearyl alcohol) incorporated in the resin or on the surface of the resin. The methods of application of the powder involves charging the powder by electrical induction/conduction and spraying the charged powder onto a grounded solid object to which it adheres prior to the thermal fusing to produce a permanent finish.
Abstract:
A rack for transporting workpieces through electrostatic coating operations. The rack includes a pair of vertically extending, rectangularly cylindrical hollow tubes having apertures formed in their front sides. A support hook has a workpiece engaging portion, offset portions extending from either end of the workpiece engaging portion, and contact portions extending from the ends of the offset portions, with each adjacent portion of the support hook extending perpendicularly to its adjacent portion. The support hook is manually engageable with the tubes by insertion of the contact portions of the hook into the apertures of the respective tubes. The hook is cantilevered to the tubes, with the workpiece engaging portion spaced from the tubes. The tubes shield their interior surfaces and the contact portions of the support hook disposed in their interiors from the sprayed particulate. Objects hung from the workpiece engaging portion of the hook biases the shielded contact portions of the hook against the shielded interior surfaces of the respective tubes to assure good electrical contact between the support hooks and the tubes.
Abstract:
An apparatus is operable to sequentially spray powder onto each workpiece of a plurality of workpieces. The powder flows from an improved nozzle assembly as a series of pulses. Accumulation of powder on surfaces in the nozzle assembly is retarded by conducting a flow of fluid (air) from a source of fluid pressure through openings in the surfaces in the nozzle assembly. Thus, a plurality of openings are formed in a side wall of the nozzle assembly to enable fluid to flow through the openings in the side wall into the flow path of air and powder through the nozzle assembly to retard accumulation of powder on an inner side surface of the side wall. An inner deflector has an end surface which faces toward the workpiece and on which powder tends to accumulate. A flow of fluid is conducted through openings in the end surface of the inner deflector to retard the accumulation of powder on the end surface of the inner deflector.
Abstract:
An apparatus for improving the electrostatic charge developed on a resin powder composition for electrostatic coating of solid objects and the method of application thereof. The apparatus comprises a device for charging the powder by electrical induction/conduction such that the powder particles have a resistivity of from about 10.sup.9 to about 10.sup.13 ohm.meters at 20 percent relative humidity and spraying the charged powder onto an grounded solid object to which it adheres prior to the thermal fusing to produce a permanent finish.
Abstract:
A powder coating system includes a powder spray booth having a single fan module which is operatively connected to at least two filter modules, each capable of being moved into position beneath or along side the powder spray booth and then moved out of position in order to permit access to the booth by another filter module. Each filter module contains a number of cartridge filters and a powder collection chamber wherein oversprayed powder removed from the booth interior can be collected for reuse or circulation back to one or more spray guns associated with the booth.