Abstract: An apparatus and method for providing a charged fluid and for creating an electret from a receptor, such as roll mill polymer film, whereby the electret will have the highest possible static electrical charge within the physical limits of the receptor. The apparatus according to the present invention includes, inter alia, a housing, a plurality of equidistantly spaced electrodes, each electrode having optimum geometry, location and electrification voltage so as to provide a maximum, uniform electric field therebetween, the electrodes collectively forming a charger grid within the housing, and a source of flowing gaseous fluid entering into the housing, the flowing gaseous fluid ionizing at the charger grid, resulting in an optimized corona within the housing. The method according to the present invention induces an optimal corona, defined as a maximum possible electric field having a strength that is near the spark over voltage, in a flowing gaseous fluid by passing the gaseous fluid past the charger grid.

Abstract: An apparatus and method for providing a charged fluid and for creating an electret from a receptor, such as roll mill polymer film, whereby the electret will have the highest possible static electrical charge within the physical limits of the receptor. The apparatus according to the present invention includes, inter alia, a housing, a plurality of equidistantly spaced electrodes, each electrode having optimum geometry, location and electrification voltage so as to provide a maximum, uniform electric field therebetween, the electrodes collectively forming a charger grid within the housing, and a source of flowing gaseous fluid entering into the housing, the flowing gaseous fluid ionizing at the charger grid, resulting in an optimized corona within the housing. The method according to the present invention induces an optimal corona, defined as a maximum possible electric field having a strength that is near the spark over voltage, in a flowing gaseous fluid by passing the gaseous fluid past the charger grid.

Abstract: This invention relates to charging means which contacts with a toner to charge the toner and being installed in a developing machine for developing electrostatic latent images by a dry developer; the charging means comprises a specified imidazole compound selected from the group consisting of an imidazole metal complex, an imidazole metal compound and an imidazole derivative.

Abstract: A multi-jet print head for a continuous ink jet printer has its individual ink jets formed electrostatically instead of using a row of individual nozzles. Ink is supplied continuously through a slot in an electrically conducting body or to an elongated edge portion of such a body, while a strong electrostatic field is applied to draw off the ink as an array of parallel cusps. These break up at their tips to form a stream of ink drops which can then be deflected in known manner. The electrostatic field preferably has a reinforcing secondary field superimposed on it, which is cyclically varied at a suitable ink drop production frequency to synchronize formation of the ink drops at each of the cusp tips. This enables means for deflecting the drops to be synchronized with the moving drops for consistent deflections and corresponding optimum resolution.

Abstract: Apparatus for the manufacture of oriented chopped glass fiber mats from non-conductive fiber feed stock is disclosed. Apparatus includes means for increasing the conductance of the feed stock, electrically insulative transfer surface; means for establishing and maintaining a directional electric field to orient the chopped fibers, and a mat receiving surface to receive the oriented mat. The non-woven mat comprises a plurality of cut or chopped fibers having their longitudinal axes predominately disposed approximately parallel to a predetermined orientation axis lying in the plane of the mat. A preferred embodiment includes the incorporation of a glass fiber mat into a composite by applying a matrix resin to the mat in sufficient quantity to ensure the integrity of the composite. The process for manufacturing said non-woven oriented mats is also disclosed.

Abstract: An apparatus and method for providing a charged gaseous fluid and for creating an electret from a receptor, such as roll mill polymer film, whereby the electret will have the highest possible static electrical charge within the physical limits of the receptor. The apparatus according to the present invention includes, inter alia, a housing, a plurality of equidistantly spaced electrodes, each electrode having optimum geometry, location and electrification voltage so as to provide a maximum, uniform electric field therebetween, the electrodes collectively forming a charger grid within the housing, and a source of flowing gaseous fluid entering into the housing, the flowing gaseous fluid ionizing at the charger grid, resulting in an optimized corona within the housing.

Abstract: An electrocoating system with multistage voltage application includes an electrocoating bath filled with a coating material and having inlet and outlet sides, a feeding arrangement for supporting and moving an object to be immersed and coated in the electrocoating bath so that the object will serve as an electrode, electrode means including a plurality of voltage-application stages arranged successively from the inlet to outlet sides of the electrocoating bath, each of the stages having at least one electrode arranged along a path of travel of an object as moved by the feeding arrangement, power supply means for applying different independently variable voltages through the stages, respectively, and diode means for preventing the electrodes of the stages from being electrocoated with the coating material, the diode means including diodes which are forward-connected respectively between the power supply means and the electrodes of the stages.

Abstract: A triboelectric charge application member for imparting or applying electrostatic charge to a toner through the triboelectric charging thereof for developing electrostatic images with the charged toner to visible toner images. The triboelectric charge application member includes an overcoat layer comprising as the main component a polymer which comprises a fluoro-olefin compound and an unsaturated silicon compound as the monomer units of the polymer. The triboelectric charge application member may be carrier particles having the above overcoat layer and a toner transportation member having the overcoat layer, depending upon its application.

Abstract: A powder charging apparatus, in which a plasma electrode pair is disposed within an insulative tubular passage for transporting powder as carried by gas, a device for intermittently applying a D.C. voltage between that pair of plasma electrode is provided to form a space where mainly desired polarity ions drawn from the plasma electrode pair exist and another space where mainly opposite polarity ions exist, well dispersed powder is fed to the former space where mainly the desired polarity ions exist, and thereby stable and strong charging performances can be assured for a long term without adhesion and accumulation of the powder to and on either one of the pair of plasma electrodes; and an electrostatic powder painting apparatus containing this powder charging apparatus therein and having excellent penetrating performance and painting efficiency.

Abstract: Apparatus and method for effecting a chemical reaction, including a mixer/charger for simultaneously mixing and electrically charging a fluid input to produce a charged fluid output, chemical reaction containment vessel for containing ingredients undergoing a chemical reaction separately from the mixer/charger, and a coupling for fluidically coupling the charged fluid output from the mixer/charger to the containment vessel to influence the chemical reaction. The method includes simultaneously mixing and electrically charging a fluid input to produce an electrically charged fluid output, and delivering the electrically charged fluid to a medium undergoing a chemical reaction to influence the chemical reaction thereof.

Abstract: An apparatus for charging insulating toner particles comprised, in operative relationship, of a means for charging insulating toner particles and a means for transporting insulating toner particles, said means for charging and said means for transporting biased to a predetermined potential wherein the transporting means contains therein a coating selected from the group consisting of a chlorotrifluoroethylene vinyl chloride copolymer, styrene copolymers, and silicone resins with conductive particulate particles therein.

Abstract: A negative field generator has a dielectric slab which is doped with discrete conductive members and sandwiched between a pair of electrodes. The electrodes and the dielectric member are encapsulated in a dielectric material and the electrodes are connected across a source of high frequency high A.C. voltage.

Abstract: A particle separator for sorting particles suspended in a liquid according to certain characteristics, including a method of and apparatus for detecting a change in the droplet breakoff point of a liquid jet stream which is subjected to vibrations. The vibrations produce amplitude undulations on the surface of the jet stream. The amplitude of the undulations is monitored or interrogated at a fixed point on the jet stream prior to the breakoff point. A change in amplitude of the undulations at that fixed point produces a signal voltage at a masked sense diode the value of which is proportional to the amplitude change. This signal voltage may be used (1) to alert the operator that a change has occurred in the point at which the jet stream is breaking up into droplets, (2) to automatically control the intensity of the vibrations for restoring the amplitude of undulation at that fixed point to its original state, or (3) to automatically disable the sorting portion of the apparatus.

Abstract: A high-intensity ionizer assembly having a Rogowski-shaped outlet. The ionizer assembly is adapted to be used with particle collection systems for pre-charging particulate matter entrained in a gas stream.

Abstract: Apparatus for ionizing air, for example for feeding to a boiler to act as a catalyst, comprises a closed container (15) which is divided into two chambers (17, 18). Water is fed under pressure to atomizing jets (21,22) which produce a mist inside each chamber. Air is fed by a pump (28) into the first chamber and passes upwards through the mist in that chamber, through an aperture (20) near the top of a partition wall (19) and downwards through the mist in the second chamber. The thus-ionized air leaves the second chamber via an outlet pipe (30) and passes through a demoisturizing coil (31). The water for feeding to the jets is contained in a reservoir (2) at the bottom of a casing (1) in which the container is mounted.

Abstract: A semiconductor memory device includes charge storage type memory cells, word lines and a bit line connected to the memory cells, a sense amplifier for detecting the memory data on the bit line, and a voltage push-up circuit for setting up a potential on the bit line. The voltage push-up circuit at first sets the potential on the bit line at a power supply voltage level after the memory data having a high logic level is detected by the sense amplifier, and then pushes up the potential on the bit line to a higher potential level than the power supply voltage.

Abstract: In order to inject a net unipolar charge, for example using a charge injector (1), into a liquid containing a dispersed contaminant without risk of blockage or arcing in the charge injector which could arise if the contaminated liquid were passed through the charge injector (1) itself, instead a substantially contaminant-free liquid is passed through the charge injector (1) and then the charged contaminant-free liquid brought into contact with the contaminated fluid in a mixing chamber (33), for example. The invention finds particular application in the electrostatic removal of contaminant from a liquid, where the mixing chamber is provided within a separation vessel (6), preferably containing a bed of densely packed beads (32). In the mixing chamber, the contaminants migrate under the influence of the electric field induced in the liquid mixture and conglomerate on the exposed surface of the beads.

Abstract: An electrostatographic method and apparatus for developing an electrostatic latent image on an imaging surface, comprises a charging doner member which is preferably a rotatably mounted roll closely spaced from the imaging surface at one portion and having a housing means to be filled with toner positioned adjacent the doner member at another portion together with a web screen located in the housing and adapted to contact the donor member on the portion of its surface opposite the imaging member; the donor member having a surface comprising an active polymer having a basic amine moiety whereby when the donor roll is rotated the rubbing contact between the toner, the screen means and the donor member produces negatively charged toner particles. In a preferred embodiment the active polymer having a basic amine moiety is selected from poly(2-vinylpyridine), poly(4-vinylpyridine), polyvinylpyrolidone, poly (dimethyl aminoethyl methacrylate) and the toner includes a minor amount of fumed silica additive.

Abstract: An apparatus and method for reducing material accumulation on processing equipment caused by electrostatic charge. By proper selection of materials, the equipment is designed to automatically develop a charge of the same polarity as that on the material being processed and thereby repel the material. The selection can be based on the relationship of the materials in the Triboelectric Series. The processing equipment is also electrically insulated from discharge paths so that the charge developed will not be dissipated or require high current generation to maintain the voltage required to repel the material particles.

Abstract: Electrostatic spraying apparatus e.g. for graphic work, having a hand or finger held body carrying a nozzle to which the atomizing potential is applied from a high voltage generator. The nozzle is of the non-drip type, e.g. a capillary bore or a felt- or fibre-tip so that no liquid is dispensed therefrom in the absence of the atomizing potential. The nozzle and liquid reservoir may be a cartridge, e.g. a felt-tip graphic marker. The generator may be within the body so as to provide a self-contained unit which can be "earthed" via the user's hand.

Abstract: A method for developing electric latent images with a triboelectrified toner without use of carrier particles therefor comprises using as a member for imparting triboelectric charges to said toner, a member containing at least on the surface at least one kind selected from poly (phenylene oxide); polycarbonate, styrene type resin, silicone resin, polymer of vinyl ester type monomer, silane compound, and polyethersulfone. Also, an apparatus for developing electric latent images comprises a toner-holding member, a means for supplying a toner to said toner-holding member and a means for moving said toner-holding member and supplying said toner to a portion for development of the electric latent images; in which at least the surface of said toner-holding member contains at least one kind selected from poly (phenylene oxide), polycarbonate, styrene type resin, silicone resin, polymer of vinyl ester type monomer, silane compound, and polyethersulfone.

Abstract: An electrostatic precipitator (10) having a casing (12) defining a precipitation chamber (6) wherein a plurality of discharge electrode subassemblies (32) are disposed alternately between a plurality of collecting electrode plates (20). Each discharge electrode subassembly (32) is comprised of a plurality of individual tubular discharge electrodes (50) extending vertically between support frame members. Each tubular discharge electrode (50) is comprised of a vertically elongated tubular member (54) having an elliptical cross-section disposed with the longer axis of the ellipse perpendicular to the collecting electrode plates and the shorter axis of the ellipse parallel to the collecting electrode plates. A plurality of corona discharge pins (52) are disposed along the length of the discharge electrodes at spaced intervals and extend outwardly from the longitudinal axis of the tubular member (54) at an acute angle preferably in the range of at least 45 degrees to not more than 60 degrees.

Abstract: An improved high-voltage discharge electrode assembly for an electrostatic precipitator is disclosed. The discharge electrode assembly comprises, in combination, an elongated discharge electrode, an anchoring element, one end of the elongated discharge electrode being secured at the anchoring element, and a flexible shroud closely surrounding the elongated discharge electrode adjacent the anchoring element whereby the life of the electrode in the electrostatic precipitator is extended. In a preferred form, the flexible shroud is a closely coiled, cylindrical helical spring.

Abstract: A particle separator for sorting particles suspended in a liquid according to certain characteristics, including a method of and apparatus for detecting a change in the droplet breakoff point of a liquid jet stream which is subjected to vibrations. The vibrations produce amplitude undulations on the surface of the jet stream. The amplitude of the undulations is monitored or interrogated at a fixed point on the jet stream prior to the breakoff point. A change in amplitude of the undulations at that fixed point produces a signal voltage the value of which is proportional to the amplitude change. This signal voltage may be used (1) to alert the operator that a change has occurred in the point at which the jet stream is breaking up into droplets, (2) to automatically control the intensity of the vibrations for restoring the amplitude of undulation at that fixed point to its original state, or (3) to automatically disable the sorting portion of the apparatus.

Abstract: A system for controlling a high-voltage supply which is inhibited for a time after energization to prevent spurious deenergization. The high-voltage supply includes a source for generating a signal representative of the desired output high voltage. A feedback voltage control responds to this signal and controls the high-voltage supply. The system includes a source for developing a linear ramp signal which varies from an initial value at which the output of the high-voltage generator is under the control of the ramp signal source to a value at which the output of the high-voltage generator is under the control of the signal representative of the desired output high voltage.

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: A charging method of an electrostatic image developer which makes it possible to electrically charge an insulating one-component developer or a two-component developer consisting of a toner and a carrier to a desired charged state and which comprises introducing the developer into a charging space between a pair of sheet-like charging members opposing each other in which space an alternating field is formed, and oscillating the developer by means of the alternating field for charging it. A developing method of a non-contact or contact system which develops the electrostatic image by use of the developer charged electrically by the above-mentioned charging method.

Abstract: A particle charging apparatus (Boxer-Charger) is constructed by disposing electrode assemblies each consisting of corona discharge electrodes and excitation electrodes, in parallel to each other with a charging space interposed therebetween. An a.c. voltage is applied between the corona discharge electrodes in the respective assemblies to establish a main electric field in the charging space. When the a.c. main voltage has entered a half cycle of particular polarity such as, for example, negative polarity, an excitation high frequency voltage including fast-rising pulses having a pulse duration time of 1 ns-1 ms is applied between the corona discharge electrodes and the excitation electrodes in the assembly to generate a creeping streamer on the corona electrode surface and thereby form a two-dimensional plasma source.

Abstract: Gas-contaminated particulate material is passed through a vacuum chamber wherein it is subjected to an electric field to charge the gaseous contaminants to cause the gaseous contaminants to separate from the particulate material and enter a gas flow path through a vacuum-outlet conduit inflow communication with a vacuum source. A series of electrical potentials are established in the vacuum outlet conduit by a series of electrodes spaced from one another. Adjacent potentials or electrodes are of opposite polarity and the distance between adjacent potentials or electrodes decreases in the direction of the gas flow path out the vacuum outlet conduit whereby the vacuum and the electrodes move the gases from the vacuum chamber.

Abstract: A method of trapping lubricant in a vacuum system and an assembly for performing same wherein a vacuum chamber has an outlet duct to a vacuum source to establish a gas flow path from the vacuum chamber to the vacuum source. Lubricant vapors from the vacuum source such as a vacuum pump are prevented from entering the vacuum chamber in accordance with the instant invention by establishing an electric field and subjecting the lubricant entering the vacuum outlet duct from the vacuum source to the electric field to electrically charge the lubricant and electrically attract the lubricant back toward the vacuum source. A magnetic field is also established between the electrodes to further urge the charged lubricant back toward the vacuum source. In this manner the lubricant is prevented or substantially prevented from entering and contaminating the vacuum chamber.

Abstract: A discharge electrode and discharge electrode assembly having longer more reliable service life than conventional tensioned wires wherein the electrode is categorized as rigid because its mechanical behavior more closely resembles that of a structural beam than a wire of equal length and the electrode in the preferred embodiment has a flattened ellipsoidal configuration with corona members projecting substantially along a plane passing through the long axis of the ellipsoidal electrode.

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: A novel method is disclosed for detecting and controlling the flow rate of a perturbed, droplet-forming stream in an electrostatic particle sorting apparatus. Detection apparatus is located at two points along the stream, at a first particle sensing point for sensing the presence of particles within a core portion of the stream, and at a second downstream point, preferably the stream breakpoint, for sensing light scatter and extinction characteristics which are proportional to the surface characteristics of the sheath portion of the stream. Changes in phase shift, pulse width, duty cycle, pulse area, or breakpoint location are detected by analyzing these sheath surface-related characteristics. An error signal is produced in response to such changes which drives an electromechanical fluid flow regulator to increase or decrease the fluid flow rate in a direction which tends to minimize the error signal. The flow rate is thus maintained at a reference flow rate setting.

Abstract: In order to initiate the charging of droplets at a specific point in time with respect to the formation of those droplets in an electrostatic flow sorting system, the charge phase of the system of the present invention is continuously and automatically adjusted by droplet break point monitoring. The charge phase is therefore flow rate and fluid velocity independent. The break point is monitored by a light source which is focused onto the jet stream at the droplet formation break point, or close to it, and the modulation of light caused by the scatter induced by the sheath stream portion as it passes the focused beam of light is detected via the use of a suitable electro-optical detector. From the output of the electro-optical detector, after appropriate signal conditioning, an electrical wave form is obtained which shape depends upon the shape of the fluid column passing the focus beam.

Abstract: A novel method and apparatus for automatically setting the time delay for relatively charging droplets in an electrostatic particle sorting system is disclosed. By utilizing a movable sheath sensing means for sensing the light scatter and extinction of this stream, the flow rate and distance to breakpoint are automatically measured and used to calculate and set the timing delay circuitry. This insures that droplet charging at the breakpoint will occur synchronously to produce selective relative charging of those droplets containing particles to be sorted.

Abstract: A method for the measurement of fluid velocity and fluid flow rate is described which may be applied to a system in which fluid is caused to exit through an orifice to form a free jet. Optical as well as fluidic properties of the jetting fluids are used to determine the mean velocity of the jet between its point of exit from the orifice and at least a preselected detection point. From the mean velocity determination, the fluid flow rate may also be determined. A marker signal perturbation is applied to the jetting fluid at the orifice, and is detected downstream at a stream sensing point which is located a preselected distance from that orifice.

Abstract: A novel method for positioning the point of droplet formation in the jetting fluid of an electrostatic sorting device is disclosed. The formation of the uniform droplets is carried out via the application of vibrational energy inparted by a transducer to a jetting laminar flow stream. Previously sensed particles contained within the core portion of the laminar stream are subsequently sorted from the stream as part of a subsequently formed droplet. The disclosed method uses the dependency of the droplet formation point on the amplitude of the wave form applied to the transducer and the modulation of this amplitude to control the droplet formation point distance. The position of the droplet formation point is detected via the use of a light source and photodetector focused on the jetting stream at the position at which the droplet formation point is to be located, and a method for automatically maintaining the breakpoint at that position is described.

Abstract: A novel method and system are disclosed for detecting the breakpoint of a perturbed flow stream. The scattering and extinction of light caused by a perturbed stream at a preselected flow stream sensing point therealong is measured to produce a real time waveform proportional thereto. The real time waveform is differentiated to produce a differentiated waveform, which is then selectively monitored to distinguish a waveform exhibiting substantially three (positive and negative) peaks per cycle, whereby such detection indicates that at least a portion of the breakpoint region of said flow stream corresponds with said flow stream sensing point. In order to align the stream sensing point with respect to a preselected point within the breakpoint region of the flow stream, the breakpoint region of the stream is caused to move with respect to the stream sensing point until the breakpoint pulse width of one of the peaks corresponds with a preselected pulse width reference.

Abstract: This invention is directed to positively charged toners comprised of a resin, a colorant, and an additive possessing an anion, and more specifically, an alkyl pyridinium compound and its corresponding hydrate, of the formulas ##STR1## wherein A is an anion, which in a preferred embodiment is selected from halides such as fluoride, chloride, bromide, or iodide; sulfate, sulfonate, nitrate borate, and phosphate; R is a hydrocarbon radical containing from about 8 to about 22 carbon atoms and preferably from 12 to 18 carbon atoms. An important embodiment of the present invention is directed to a process for rapidly charging (or admixing) uncharged dry electrostatographic toner, containing the alkyl pyridinium compounds of the above formulas, subsequent to its addition to previously charged developer, whereby the uncharged toner particles acquire a charge within a period of from about 1 minute to about 5 minutes.

Abstract: Static charges and agglomeration of particles in a fluidized bed system are minimized by maintaining in at least part of the bed a radio frequency glow discharge. This approach is eminently suitable for processes in which the conventional charge removing agents, i.e., moisture or conductive particle coatings, cannot be used. The technique is applied here to the disproportionation of calcium peroxide diperoxyhydrate to yield calcium superoxide, an exceptionally water and heat sensitive reaction.

Abstract: An electrostatic spray gun apparatus for coating systems having an entirely self-contained light weight electrical power supply adapted to convert the kinetic energy available in a moving air stream into the required high d.c. potential and which dispenses with external electrical supply connections thereto.

Abstract: A system for charging dust and the like particles entrained in a gas stream and which are to be electrostatically precipitated. An emitter electrode is disposed in the gas stream for producing ions of one polarity which charge particles in the gas stream. These ions of one polarity and the charged particles are attracted to a surface on which at least a portion of the charged particles collect. The invention resides in the use of a second emitter electrode for producing ions of the opposite polarity which neutralize the ions of the first polarity which have been attracted to the surface and prevent the build-up of a voltage gradient across the particle layer on the surface.

Abstract: An electrostatic powder painting gun head in which a needle electrode is provided at a central portion in the proximity of a cylindrical powder ejection port made of insulator, an annular strip electrode is disposed outside of the powder ejection port, also a gas injection port for forming a gas flow layer along the surface of the annular strip electrode is provided, and further there is provided a high voltage power supply for applying a predetermined voltage between the needle electrode and the annular strip electrode.

Abstract: On the downstream side of a large-diameter cylindrical flow path is disposed a small-diameter cylindrical flow path having a smaller inner diameter than the inner diameter of the large-diameter cylindrical flow path contiguously to the large-diameter cylindrical flow path, an annular electrode is disposed at the upstream end of the small-diameter cylindrical flow path, a needle electrode is provided at the center of the annular electrode applying a D.C. high voltage between the electrodes, and upon charging powder contained in a mixed-phase flow through said cylindrical flow paths, a substantial slip velocity is given to the mixed-phase flow adjacent to the surface of the annular electrode.

Abstract: A persistent electric charge is introduced into melt-blown fibers during the melt-blowing process. When these charged fibers are incorporated into fibrous webs, they provide unique properties, including improved filtering properties.

Abstract: In a device for electrically charging particles, a pair of parallel plasma generators are spaced from one another, each of the generators having corona discharge electrodes. A main field forming source of high AC voltage is connected between the plasma generators, to form a main field in the charging space, and intermittently operating corona generating high voltage power sources are coupled to apply high voltages to the respective corona discharge electrodes only when the plasma generators have relative specific polarity, whereby only particles of one polarity are driven into the charging space. The intermittent corona generating high voltage source has a frequency equal to or greater than the frequency of the AC voltage which provides the main AC field.

Abstract: A plurality of wire-shaped electrodes are arrayed at equal intervals within a plane insulator layer, and an electric power source for applying an A.C. voltage between adjacent ones of electrodes is connected to the electrodes via protective resistors so that an electric field in a curtain form is established between respective electrodes. The resistance value of the protective resistors between the electric power source and the electrodes and the resistance of the electrodes themselves are respectively selected higher than a minimum A.C. ignition resistance that is necessary for preventing ignition by spark discharge of powder to be processed by the curtain-like electric field. This prevents powder explosion induced by a spark discharge caused by a fault occurring in one part of the electric field curtain.

Abstract: An ink jet printer provides a nozzle for ejecting droplets of inflammable ink towards a recording surface and a charging electrode for imparting a charge to the droplets in accordance with information to be printed. Deflecting electrodes are positioned between the charging electrode and the recording surface. A deflecting source supplies the deflecting plates with a predetermined deflecting voltage. A resistor is connected between one of the deflecting plates and the deflecting source.

Abstract: A powder spray machine for internally coating containers such as metal cans comprising infeed means, container positioning means, powder coating apparatus, container outfeed means, and powder control means. A rotary mask plate is provided with openings for reception of the open ends of cans that are carried by a star wheel adjacent the mask plate and are axially aligned with powder spray means adjacent the other side of the mask plate. Means are provided for controlling the overspray of powder to protect areas of the machine and prevent build-up of powder in any area of the machine, and from entering air outside of the machine. A single plate arrangement supports the container positioning means and thus allows access to the container positioning means for powder control means.

Abstract: A method for the manufacture of an electrically charged fibrous filter from a highly molecular non-polar fiber material wherein a .[.web.]. .Iadd.film .Iaddend.of the fiber material is continuously fed and stretched. At least one side of the stretched .[.web.]. .Iadd.film .Iaddend.is homopolarly charged by a plurality of corona charging elements. The charged .[.web.]. .Iadd.film .Iaddend.material is then fibrillated, collected and processed into a filter.