摘要:
The disclosure describes the use of electrostatics to in-mold labeling wherein a label is secured to a mandrel with an axis-defining body, a first end, a distal end, a set of ionizing electrodes disposed about the body, near the distal end, and in a plane perpendicular to the axis. When the mandrel is positioned in a mold cavity, the label is released and a varying voltage applied to the electrodes to form a substantially uniform and ring-like source of ionizing current. The ionizing current progressively pins the label against the die as the mandrel is withdrawn from the die until substantially the entire label is pinned. The ionizing current may then be ended and the mandrel removed so that an article may then be formed into the label.
摘要:
Simultaneous neutralization and monitoring of charge on a moving dielectric material is achieved with ionizing devices that supply ions in proximity to the material to thereby substantially neutralize charge on the material, and with circuitry that senses the ion currents flowing from the ionizing devices to the material. A controller can be utilized to control the ionizing devices and/or calculate various parameters (such as charge densities on the web, efficiency, etc.) based on the sensed ion currents.
摘要:
The total of the ion current leaving electrodes of one polarity and the ion current flowing to those electrodes, is measured as the current in the ground return path of the corresponding generator. For a brand-new ionizer, the value of that total ion current for electrodes of each polarity under normal operating conditions will substantially be the maximum ion current the positive and negative electrodes are capable of generating. The changes in the current in the ground return path reflect changes in the ionizing efficiency of the electrodes caused among other factors, by contamination. The values of the currents may be scaled up or down to the arbitrary unit. Using this scaling allows to have a signal that is normalized regardless of the length of the ionizer and number of the ionizing electrodes.
摘要:
A balancing system for electrical A.C. air ionizers having at least one discharge electrode adjacently spaced from a proximity ground and connected to the high side of an A.C. high voltage power source includes (a) a capacitor interposed between each electrode and the high voltage source to maintain a bias on each of the electrodes by blocking the D.C. current component across the circuit capacitance between the discharge electrodes and ground, and (b) a by-pass resistor across the circuit capacitance for providing a path to ground to bleed off excess bias so that equal positive and negative ion densities are generated during corona flow, the by-pass resistor having a resistance value which is determined by the parameters of the system's corona characterisitics (including corona onset voltage and average current flow) that will provide a required equilibrium bias for producing the correct ratios of positive and negative ion currents as will balance the ion densities. Adjustable means are also provided for varying the by-pass resistance to compensate for changes in positive and negative ion flow that are caused by environmental factors and contamination.
摘要:
Electrostatic charging performance may be improved by determining a satiation charging current for objects/products passing through a charging system and then applying the determined satiation charging current the objects/products. Charging performance may be improved in either or both of discontinuous product train applications or continuous web applications.
摘要:
Ionizing method and apparatus includes a pair of inverters to supply ionizing voltages to ionizing electrodes only during alternate halves of a duty cycle in which one inverter is actuated to operate at high oscillating frequency while the other inverter is inactive, and thereafter in an alternate half of the duty cycle in which the one inverter is inactive and the other inverter is actuated to operate at high oscillating frequency. Each inverter includes a return current path that combines in a common return path in which return currents may be monitored for selective control of one or both of the inverters. Small step-up transformers and other components operating at high oscillation frequency promote confined packaging of high voltage generators for convenient mounting adjacent a pair of ionizing electrodes to reduce lengths of heavily-insulated high-voltage cables between generators and electrodes. Each electrode only operates on one polarity of high voltage derived from half-wave rectified high-frequency oscillations during the actuation of the associated inverter. Closely-spaced mounting of the electrodes adjacent a web of material having net electrostatic charge to be neutralized facilitates alternately supplying ions of each polarity from separate ones of the electrodes to neutralize charge on the web.
摘要:
An apparatus for simultaneous electrical discharge treatment and adhesive application to a polymer component. The apparatus includes a jig having an electrically conductive region and a dispenser having an electrically grounded dispensing tip with a dispenser orifice which functions as an electrode as it is moved across an upper surface of the polymer component in close proximity thereto. During such movement, the tip coacts with the jig which underlies the component and to which high voltage is applied to create an electrical discharge which is directed onto the component and makes the surface thereof susceptible to bonding with adhesive applied to the component from the tip virtually simultaneously with the discharge.
摘要:
An apparatus for treating the surfaces of formed plastic articles including a plurality of bare metal discharge electrodes connected to a high frequency AC power supply, a counterelectrode disposed in spaced relation to the discharge electrodes for defining a treatment zone therebetween, and an insulation layer mounted in spaced relation to the counterelectrode such that a discreet air space exists between the insulation and counterelectrode for moderating the electrical discharge between the discharge electrodes and counterelectrode and enabling greater control and uniformity in the electrical discharge between the electrodes and counterelectrodes. In the illustrated the embodiment, a first set of discharge electrodes define a first treatment zone for treating one-half of the circumferential surface of articles directed through the first treatment zone and a second set of discharge electrodes define a second treatment zone for an treating opposite peripheral half of the circumferential surface of articles passing through the second treatment zone.
摘要:
A method and apparatus adapted for the rapid, accurate and repeatable determination of contact angles of liquid droplets applied to curved substrate surfaces. The apparatus includes a support upon which an article may be mounted with the curved substrate surface facing downwardly, a pipette having a discharge end below the downwardly facing curved surface and operable for transferring a predetermined relatively small droplet of a test liquid onto the downwardly facing curved surface, and a contact angle measuring device which includes a lamp for directing a light beam across the suspended droplet such that an image thereof is projected onto a screen from which the contact angle is measurable.