Abstract:
The present invention is directed to electrostatic chucks, methods for their use, the electrostatic deposition of particles on an objects, and the objects themselves that have been subjected to electrostatic deposition. In one aspect, the present invention provides an electrostatic chuck for electrostatically attracting an object or objects wherein the object is used in chemical or pharmaceutical assaying or manufacturing, and optionally wherein the object is less than or equal to one millimeter in average width or diameter. The objects can be pharmaceutical substrates, for example, such as a pharmaceutical tablet. Additional embodiments of the invention provide chucks and their use to electrostatically attract particles, such as a pharmaceutically active ingredient, to a substrate, such as a tablet. In one aspect, the electrostatic chuck comprises a floating electrode, and is used to selectively attract particles to a substrate above the floating electrode, thereby providing for charge imaging for the deposition of particles in a selected image. Additionally, the invention provides an electrostatic chuck comprising a sensing electrode for sensing the number of particles attracted to the chuck, thereby providing for deposition of an accurate amount of particles. Furthermore, the present invention provides objects having selected areas in which particles are applied to the object via electrostatic means.
Abstract:
An electrostatic coating facility for an electroconductive coating material comprising a coating machine disposed in a coating zone while being grounded to the earth, an insulated conveyer disposed in the coating zone for conveying an object to be coated in an electrically insulated state and applying a high voltage to the object, an entering conveyer disposed for carrying the object into the coating zone, a delivery conveyer for carrying the coated object out of the coating zone, and a relay transfer device interposed between the insulated conveyer 1 and the entering conveyer or the delivery conveyer for transferring the object in an electrically insulated state while keeping a required insulation distance between each of them. Aqueous coating material free from public pollution can be used with no troubles for taking insulative measures on the side of the coating machine and without worry of spark discharge.
Abstract:
Apparatus (74) and method are provided for electrostatically depositing particles (64) of a first material onto a sheet (18) of a second material, and for electrostatically neutralizing the residual charge. The apparatus (74) includes a particle generator (20) for aspirating particles (64) of the first material, electrodes (60a and 60b) for electrostatically charging the particles (64) to a first polarity, an electrode (75) for electrostatically recharging a portion of the particles (64) to the opposite polarity, and a depositing chamber (22) for electrostatically depositing the particles of the opposite polarity subsequent to depositing the particles of the first polarity.
Abstract:
An electrostatic powder coating method and apparatus therefor, in which an auxiliary electrode is disposed in the vicinity of a desired coating surface of an object to be coated, a gun for performing electrostatic powder coating is directed to the object to be coated and the auxiliary electrode, a DC electric field is formed between the gun, the auxiliary electrode and the object to be coated, the auxiliary electrode is electrically charged to the same polarity as the gun so as to form an auxiliary electric field between the auxiliary electrode and the desired coating surface of the object to be coated whereby a powder coating material is transferred to be applied onto the desired coating surface by the electric field.
Abstract:
Relatively small parts are powder coated without fixturing by placing the parts on a heat conductive surface and the powders are distributed over the exposed surfaces of the parts. The powders on the surfaces of the parts are heated to fuse the powders, as by radiant heat, while the heat conductive surface is kept at a temperature below that at which overspray powders on the conductive surface will become tacky. In a preferred embodiment, the heat conductive surface is an endless belt which advances the parts past a powder coating station, past a top heating-bottom cooling station and then to discharge.
Abstract:
Apparatus for conveying elongated objects of small diameter. After an object is coated with a protective coating, a first conveyor flight having a generally V-shaped groove receives the leading end of the object. A second conveyor flight has a generally U-shaped groove to be positioned in alignment with the object for receiving it if additional support is necessary, although generally remaining out of contact with the object. Another one of the aforedescribed first conveyor flights follows each of the aforedescribed second conveyor flights so that both ends of the object are normally supported by one of the first conveyor flights. In the event either end of the object misses one of the moving first conveyor flights, an adjacent second conveyor flight will receive the object and support it for movement. In a modified form of the invention the second conveyor flight having the U-shaped groove is eliminated and a second flight having a V-shaped groove which is removably inserted into the conveyor is utilized if needed.