Abstract: A method and apparatus for electrostatically spraying conductive coating material onto objects, primarily large extended objects, by charging with a relatively large charge the space behind the surface to be coated. With hollow objects, such as automobile bodies, the space within the body is charged. The space is charged by spraying an electrostatically charged atomized water mist into the space which evaporates charging the space and object surface. An electrostatic field is produced between the surface and the gun which, along with the supply of conductive material to which it is connected, is grounded. The gun discharges a film of coating which is atomized into droplets. The field inductively charges the film fringe and thus the droplets which are then attracted onto the large charged surface.

Abstract: An electrostatic coating method and apparatus are provided that are capable of applying an extremely thin and virtually constant thickness coating to a substrate, and includes a coating applicator having an opening formed of dielectric material through which coating material flows for coating purposes. The coating material supplied to the applicator is pressurized to maintain a substantially constant volume of coating material at the applicator opening output and is vibrated in the vicinity of the applicator opening to provide a uniform flow of coating material to the applicator output, to stabilize the shape of the coating material at the applicator output and to preclude changes in coating material flow rate caused by electrostatic field induced coating material dryout.

Abstract: A process for the formation of a deposited functional film by separately introducing, into a film-deposition space (A) for forming a deposited film on a substrate, a precursor as the starting material for forming a deposited film which is formed by applying a microwave energy in to a precursor-generating gaseous raw material a decomposition space (B) and an active species which is formed in a decomposition space (C) and which is chemically reactive with the precursor, respectively and chemically reacting them to thereby form a deposited film on the substrate, wherein the inner wall face of a chamber constituting the film-deposition space (A) and the inner wall face of a chamber constituting the decomposition space (C) are coated with a thin film constituted with an element or ingredient constituting the deposited film having a resistance value of 10.sup.6 .OMEGA..cm or more, thereby preventing intrusion of impurities from inner wall material into the deposited film.

Abstract: A spray disk (4) rotating at high speed and connected to high voltage surrounds a guide rod (30) and can be reciprocated up and down along said guide rod, the latter being of a stationary arrangement. This permits the use of drive means (34, 50) which extend along the guide rod (30) so that for the up and down motion of the spray disk (4) there are no carrier rods required which protrude beyond the stroke of the spray disk beyond the device.

Abstract: A painting system for painting a finned-tube heat exchanger suspended from a conveyor line so as to be conveyed thereby, comprises: (i) means for spraying on said heat exchanger with a water-soluble paint; (ii) means for air-blowing on said heat exchanger; and (iii) means for electrostatic spraying on said heat exchanger with a solvent-soluble paint. Each of spray nozzle assemblies and air-blow nozzle assemblies of said means issues paint spray or air blow to fins of said heat exchanger in a direction parallel to said fins. This painting system further comprises a scraper means for recovering said water-soluble paint sprayed and reached a wall member during spraying and air blow.

Abstract: A rotary type electrostatic spray coating device comprising two or more side spray coating units having two or more spray heads separated from each other at a distance larger than a width of the coating pattern of each spray head, and the same negative high voltage is simultaneously applied to all of the spray heads during a spray coating operation; thus enabling a shortening of the length of the spray coating booth, improving a flatness of the paint coating on the work pieces, and completely preventing an undesirable deposition of paint mist on the spray heads.

Abstract: In an apparatus for electrostatically coating workpieces with an electrically conductive coating material, an intermediate isolation tank (V) is conencted by electrically insulating conduit lines (LVA, LVB, LZA, LZB) between an electrically grounded coating material supply and a high voltage spraying device atomizer (Z). When the apparatus is in operation, the conduit lines (LVA, LVB, LZA, LZB) are alternately filled and emptied, such that the grounded supply and the high voltage atomizer (Z) are continuously insulated from each other. One embodiment utilizes an isolation tank V' which includes a metering cylinder (DZ) having a displaceable piston (2) for adjusting the coating material capacity of the tank (V') to the amount required to coat a single workpiece.

Abstract: An electrostatic blade is disclosed having a slot extending the length of the blade and leading from a central duct to an outlet. A surface made of non-conductive material extends in front of the outlet and terminates in a discharge edge which is spaced 0.05 to 4 mm from the slot outlet. In use, liquid is passed from the duct along the slot to the outlet where it collects as a bead. An electrostatic field is applied between the liquid at the slot outlet and the object to be coated which draws liquid along the non-conductive surface in a tapering stream and further causing the liquid to be discharged from the edge. Because the stream of liquid reaching the discharge edge is very thin, very low liquid discharge rates can be achieved while still maintaining a uniform coating on the target object.

Abstract: A method and apparatus are provided for controlling the width and improving edge thickness uniformity of a layer of coating material electrostatically deposited on a moving web surface. The apparatus preferably includes a coating applicator, a rotatably mounted web-supporting backing roll spaced therefrom and a source of electrical power coupled between applicator and backing roll for generating a coating material charging and transporting electrostatic field capable of transporting the charged coating material from the applicator to a web surface as the web moves between applicator and backing roll for web coating purposes. The apparatus additionally includes a pair of electrodes coupled to a source of electrical power and mounted in an opposed relation on opposite sides of the charged coating material moving between the coating applicator and the web surface spaced therefrom.

Abstract: A method and apparatus for electrostatically applying a layer of coating material to a moving substrate. In a preferred embodiment, a threaded shaft formed of dielectric material, having one end thereof coupled to a drive motor, has a portion of its threads mounted for rotation through a bath of coating material. An electrostatic field of predetermined magnitude is established between the coating material and a substrate surface spaced therefrom. The electrostatic field atomizes coating material accumulating on the ridge portion of the rotating thread and subsequently deposits a layer of the atomized coating material on the adjacent substrate surface as it is moved past the rotating dielectric thread at a predetermined angle with respect to the axis of rotation of the threaded shaft.

Abstract: The invention provides methods and apparatus for conducting electrostatic spray coating by which an improved coating layer made uniform in gloss, hardness, weather-tightness, and other characteristics is obtained on an object to be coated. The coating layer is formed with use of a rotary spray head device which is provided with a funnel-like body having an inner wall surface and an open end portion. The rotary spray head device is driven to turn on an axis of rotation surrounded by the inner wall surface of the funnel-like body, and supplied with plural kinds of coating material which are discharged to a substantially common location on the inner wall surface of the funnel-like body simultaneously through respective separate paths so as to form their respective layers superimposed on said inner wall surface of the funnel-like body and move toward said open end portion of the funnel-like body.

Abstract: An electrostatic spray device and cable assembly for charging coating material applied to an article in industrial finishing operations includes a gun body having a powder flow passageway and a dielectric sleeve contained within the passageway such that the discharge opening of the spray device surrounds the sleeve. The cable assembly comprises a dielectric tube having a hollow interior and a high voltage electrostatic cable mounted within the tube and connected at one end to a supply of electrostatic voltage. A particle deflector having an electrode in the form of a resistive sheet is mounted by the tube in charging relationship to a coating particle discharge opening in the spray gun, and the opposed end of the cable is electrically connected to the electrode. An adjustment device acts on the tube and cable to move them as a unit within the passageway in the spray gun to adjust the axial position of the deflector and electrode relative to the particle discharge opening in the spray device.

Abstract: Method and apparatus for charging powdered particles and delivering only these charged particles to a workpiece. A high voltage electric field is created between upper and lower surfaces. Powder is continuously delivered to the lower surface. The lower surface is vibrated to bounce the particles so that each repeatedly contacts the lower surface and picks up an electrostatic charge with each contact. When the charge from the particle is great enough to overcome gravity, the particle levitates and is thereafter transported to a workpiece, where it adheres by electrostatic attraction. Three important features of this method are: (1) No uncharged particles are levitated to the workpiece, thereby eliminating the need for recirculating uncharged powder. (2) The method is capable of producing high throughput of charged particles. (3) The method is capable of producing powder with a controlled charge level.

Abstract: The invention relates to a process and an apparatus for applying two or more colors of paint by applying a first paint to at least part of a substrate, followed by a second and, if desired, further different-colored paints to different parts of the substrate and hardening the applied coats of paint by baking, which comprises applying the second and if desired the further different-colored paints without interim baking of the first paint to the preselected different parts of the substrate using electrostatic atomization at stationary atomizer edges involving transport of the paint particles in an electric field and, after the first and subsequent paints have been applied, hardening all coats of paint together by baking.

Abstract: The present invention relates to a powder distributor for electrostatic painting provided with reciprocating vertical movement, wherein the powder in mixture with air reaches the center of a sectional element, for example a disk, which disperses it evenly over its perimetral rim.The distributor comprises a reservoir divided into two chambers by an intermediate porous septum, a first, upper chamber into which a first, powder-in-air suspension feed circuit debouches, and a second, lower chamber into which a second, compressed air feed conduit debouches. Provision can also be made for a third conduit, for compressed air feed, the compressed air being in such case discharged parallel to the direction of discharge of the powder suspension.

Abstract: An electrostatic spray coating apparatus. Piping for supplying paint, operating air, etc. is divided in the middle of its course between a pressurized air source and downstream portions such as an air motor and a color-change valve, and is connected by a joint at these divided points. The apparatus can thereby be put to functional testing before it is installed on its work spot.

Abstract: A conical sheath of air emitted from a vortex plenum adjacent the outer edge of a rotating bell spray apparatus is effective to optionally help atomize the coating material, and to carry the atomized material forwardly toward a confluence on the axis of the rotating head where tubulent mixing of the particles occurs, and the particles are sprayed forwardly for deposition in a uniform thickness film of a uniform population mix of particles sizes. Forward air and tangential air components are admitted to the plenum and are independently controlled so that different spray characteristics are obtained, the tangential air providing a swirl moment to the conical air sheath which enlarges the size of the deposited film pattern. The forward velocity determines the atomization ability of the sheath air and the particle velocity in the spray pattern. Electrostatic and non-electrostatic operations are intended.

Abstract: The present invention relates to a process and an apparatus for electrostatic application of liquids or powders on many different substances and objects, by means of a cone diffusing the substances or objects to be coated, in free fall continuously along the internal wall of a tube where a high voltage positive corona zone is produced, while the liquid or powder is prayed from a centrifugal atomizer, by which a high voltage negative corona zone is produced, so that the liquid or powder is charged negatively and is attracted by the substances or objects charged positively and sliding on the wall of the tube.

Abstract: An electrostatic coating process which comprises feeding a liquid paint in thin film form toward the circumferential edge of a high-velocity rotating member having a high voltage applied thereto along the inner circumferential surface thereof and atomizing the paint from the circumferential edge of the high-velocity rotating member; characterized in that a number of cuts are formed on the circumferential edge, and a stream of the paint flowing forwardly substantially in the axial direction of the high-velocity rotating member is converted at said circumferential edge into a number of diametrically outwardly flowing divided paint streams and simultaneously atomized and discharged. Preferably, the paint is fed to the inner circumferential surface of the rotating member through an annular paint flow passage having knurled grooves formed over its entire outer circumferential surface.

Abstract: Apparatus for improving the uniformity of a wet coating applied on a charge-retaining base material, said apparatus comprising charging means for producing an electric field between said coating and said base material while said coating remains in an essentially wet state.

Abstract: Excessive heat-generating current levels produced in semiconductive materials by electrostatically assisted coating apparatus employed to, for example, improve the uniformity of a coating applied to such materials are avoided by passing an auxiliary current through said semiconductive materials in the same region and in a direction opposite to that of the current produced by said electrostatically assisted coating apparatus such that the difference between the said current produced by said electrostatically assisted coating apparatus and the said auxiliary current is less than or equal to a predetermined value.

Abstract: A paint sprayer is disposed substantially on the axis of an almost closed (omega-shaped) loop formed by a transporter. Its axis of rotation is aligned so that the area in which the sheet of atomized paint it produces intersects the cylinder defined by the axes of the objects to be painted lies in an area contained between but reaching as far as circles delimiting the part-cyclindrical surface over which the objects move. An annular nozzle connected to a source of pressurized gas is disposed behind a rotating bowl of the sprayer so that an annular gas jet is directed onto the initial part of the thin sheet of atomized paint. The pressure of the gas fed to this nozzle is modulated periodically so that the aforementioned intersection area reaches the delimiting circles alternately and periodically.

Abstract: Electrostatic spraying for pesticides comprises an electrically conducting or semi-conducting surface; means for supplying liquid adjacent the surface; and a field intensifying member in close proximity to the surface. A process for the ultra-low volume application of concentrated pesticidal formulations by means of the apparatus is also described.

Abstract: Improved electrostatically assisted coating apparatus for placing an electrostatic dipole-type charge, of a predetermined magnitude, on material to be coated before and/or remote from the location where the coating is actually applied to said material by a coating applicator.

Abstract: An apparatus for electrostatically coating an object using electrostatically charged powder grains. The invention improves upon the spray bell sprayer by having a fixed hollow shaft providing a central supply line for the powder grains, the spray bell rotates about the hollow shaft and a plurality of compressed air nozzles pass radially into the hollow shaft.

Abstract: Process for electrostatically coating objects with a fluid, for instance liquid paint, by applying a high voltage to a spray bell and by feeding the fluid to a revolving, driven spray bell. The flow-rate of the fluid supplied to the center of the spray bell is decelerated nearly to zero when it enters the bell, then the rate of the fluid is increased by being accelerated by the bell to 15,000 to 60,000 rpm, and the fluid thereupon is centrifuged off the spray rim of the bell and is guided to the object to be coated.

Abstract: Spraying apparatus for spraying liquid pesticides on to crops growing in the ground includes a plurality of electrostatic spraying devices mounted on a boom which can be mounted on a powered vehicle such as a tractor or an aircraft. Each spraying device includes a spray-head having an at least electrically semi-conducting surface charged to a potential of the order of 1-20 kilovolts, a field intensifying electrode mounted adjacent the spray-head surface and being so sited relative to the spray-head surface that the electrostatic field thereat causes pesticide liquid delivered thereto to atomize without substantial corona discharge to form electrically charged particles.

Abstract: Rotary devices for atomizing liquid coating material are characterized by a housing having a circular front wall, a generally cylindrical side wall and a plurality of circumferentially spaced passages formed therethrough in proximity with the juncture of the front and side walls. Coating material smoothly introduced into the housing onto the front or side wall is carried in a thin film by centrifugal force toward and into the passages for being projected therefrom and atomized, and an electrostatic field is established between the device and an article to be coated for electrostatic deposition of coating material on the article. The device is rotated at a relatively high speed, and the passages bring the coating material to the full rotational speed of the device as it is projected therefrom, whereby atomization and the quality of the coating on the article are improved.

Abstract: In a distributor for coating powders for electrostatic coating apparatus, an insulator shield member is provided on top of the powder distributor disk, preventing accumulation of charged powder thereon which might otherwise result in uneven distribution of powder from the distributor.

Abstract: Electrostatic spraying of liquid compositions is carried out by supplying the liquid to a spray orifice, preferably of capillary dimensions, having a charged surface which is electrically conducting or semi-conducting and which is adjacent a field intensifying electrode, the arrangement being such that the liquid is drawn out primarily by electrostatic forces, atomized into electrically charged particles without substantial corona discharge and projected past the field intensifying electrode. The spraying process and apparatus has particular utility in the spraying of liquid pesticide compositions at ultra-low volume, in that the droplets are of uniform size and are electrostatically attracted to the plants so as to wrap around the leaves of the planets and coat both the upper and lower surfaces of the leaves.

Abstract: Apparatus for electrostatically coating an elongated object of indefinite length which is aligned with the straight line path of the elongated object in a continuous manufacturing and finishing process. Electrostatic applicators are mounted to direct the coating into a substantially closed chamber at a portion of the elongated object passing therethrough. To substantially eliminate the explosive hazard occasioned by the use of an organic solvent-based coating material in the presence of electrical equipment, a combustibly inert atmosphere is maintained in the chamber and in an exhaust system leading therefrom. To maintain the electrostatic field, the coating chamber and associated coating equipment must be electrically isolated from ground.

Abstract: A device for the production of a non-woven product from a fluid dielectric substance, comprising a first electrode, means for leading this electrode along a closed path, driving means to move this electrode along this path, coating means for coating this electrode with the said substance opposite a first portion of the said path, a second electrode whose surface is relatively extensive with regard to the first electrode, located opposite a second portion of the said path, an electrostatic generator connected to one of the said electrodes to establish a potential difference between them so as to create an electrostatic field capable of acting on the said substance to form a plurality of fibers in the direction of the said second electrode, characterized in that it comprises two endless transport bands mounted respectively around guide means defining two closed parallel trajectories passing near the coating means and the said second electrode, these bands being connected to the said driving means so as to move

Abstract: An apparatus for atomizing and dispensing a coating material includes a turbine having a housing and a shaft for rotatably supporting an atomizing device. The shaft includes an outer end extending from the housing for mounting the atomizing device. The shaft outer end includes a tapered portion, and the atomizing device includes a central tapered aperture for receiving the tapered portion of the shaft outer end. The housing is divided into a high-pressure side and a low-pressure side by a nozzle plate which directs the flow of compressed air from the high-pressure side across a driven wheel mounted on the shaft adjacent the nozzle plate. The high-pressure side lies between the atomizing head and the nozzle plate so that compressed air moving through the nozzle plate and the driven wheel to the low-pressure side flows away from the atomizing head.

Abstract: An apparatus for electrostatically coating conductive articles with powder. A mixture of powder and air is delivered through a passage of uniform cross-section and a short section of rotating tube to a rotating bell of nonconductive material having a surface angle with the axis of 50.degree. to 90.degree.. The powder is directed from a nozzle over the bell surface and the entraining air is dissipated laterally. The powder is discharged from the bell into an electrostatic field where the particles acquire a charge and are attracted to and deposited on the grounded articles. A pneumatic jet pump for entrailing the powder particle in an air stream has a nozzle and venturi so related that the expanding air from the nozzle blends with the expanding portion of the venturi.

Abstract: An apparatus for electrostatically coating conductive articles with powder. A mixture of powder and air is delivered through a passage of uniform cross-section and a short section of rotating tube to a rotating bell of nonconductive material having a surface angle with the axis of 50.degree. to 90.degree.. The powder is directed from a nozzle over the bell surface and the entraining air is dissipated laterally. The powder is discharged from the bell into an electrostatic field where the particles acquire a charge and are attracted to and deposited on the grounded articles. A pneumatic jet pump for entraining the powder particle in an air stream has a nozzle and venturi so related that the expanding air from the nozzle blends with the expanding portion of the venturi.

Abstract: In a process for the production of fiber filters, spinning solutions are electrostatically sprayed and deposited continuously onto a gas-permeable band-form support. The band-form support travels successively through several spray zones and is always guided from one spray zone into the next below the spray electrodes. Row arrangements of rotating rings dipping into the spinning liquid are used as the spray electrodes, the rings of one row lying in one plane.

Abstract: Powder to be used for coating articles electrostatically is maintained in a fluidized condition in the supply container and in conveyor ducts all the way to a discharge over the inner wall of an annular channel onto the rotating disk of an electrostatic coating machine.

Abstract: An electrostatic spray gun for liquid paint has its nozzle formed in a sintered material that consists of an electrically non-conductive matrix, e.g. polytetrafluoroethylene, with conductive particles, e.g. bronze powder, dispersed in the matrix. The rear end of the nozzle is connected to high voltage, and the annular front surface around the paint discharge orifice in the nozzle is machined so that it shows a lot of such bronze particles that form point electrodes for producing air ions. The paint is dispersed by air jets and the air ions attach to the paint particles.

Abstract: A method of atomizing liquid paint using a rotating atomizing device and electrostatically coating an article with a smooth homogeneous film of paint and without the generation of foam or other surface irregularities on the article being coated, wherein an electrostatic field is established between the peripheral edge of the rotating atomizing device and the article to be coated and the liquid paint flows toward the edge of the atomizing device as a continuous thin film, which film is formed into a circumferential series of branch flows of narrow width flowing in the peripheral direction of the atomizing edge, and the liquid paint is atomized from the series of branch flows as they are projected beyond the edge of the atomizing device. The rotary atomizing device may be in the form of a bell or disk and includes a plurality of shallow grooves near its periphery preferably extending radially and of increasing depth in the direction of paint flow and terminating at the discharge edge.