Antistatic device and associated operating method

Patent metadata

Field	Value
Publication number	US-10476240-B2
Application number	US-201214111139-A
Country	US
Kind code	B2
Filing date	Apr 10, 2012
Priority date	Apr 11, 2011
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

An antistatic device for reducing electrostatic charges on moving material webs may include an active positive electrode assembly having a plurality of active individual positive electrodes electrically connected to a positive high voltage source. The device may include an active negative electrode assembly having a plurality of active negative electrodes electrically connected to a negative high voltage source. A sensor system may be included for detecting a polarity of a neutralizing current between the material web and the antistatic device during operation of the antistatic device, and a controller for controlling the high voltage sources. The controller may be coupled to the sensor system and may be at least one of programmed and configured to one of active or leave activated the high voltage source required in each case and one of deactivate and leave deactivated the high voltage source not required in each case in response to the detected polarity of the neutralizing current.

First claim

The invention claimed is:

1. An antistatic device for reducing electrostatic charges on moving material webs, comprising:
an active positive electrode assembly including a plurality of active, needle-shaped individual positive electrodes electrically connected to a positive high voltage source during operation of the antistatic device;
an active negative electrode assembly including a plurality of active, needle-shaped individual negative electrodes electrically connected to a negative high voltage source during operation of the antistatic device;
a sensor system for detecting a polarity of a neutralizing current between the material web and the antistatic device during operation of the antistatic device;
a controller for controlling the high voltage sources; and
a sensor electrode assembly including a plurality of needle-shaped individual sensor electrodes and is electrically connected to a grounding element during operation of the antistatic device;
wherein the controller is coupled to the sensor system and is at least one of programmed and configured to one of activate and leave activated the high voltage source required in each case and one of and deactivate and leave deactivated the high voltage source not required in each case in response to the detected polarity of the neutralizing current;
wherein the controller actuates the respectively activated high voltage source, the high voltage source configured to deliver one of a non-pulsed positive and negative DC voltage;
wherein the sensor system is at least one of programmed and configured to monitor the current flowing out from the sensor electrode assembly in order to detect the polarity of the neutralization current;
wherein the controller is at least one of programmed and configured to determine the polarity of the neutralization current of the sensor electrode assembly during the learning phase and switch to the working phase in response to the detected polarity, and in said working phase the controller actuates the high voltage source of the required active electrode assembly for generating the non-pulsed DC voltage; and
wherein the controller is at least one of configured and programmed to one of:
during the learning phase, actuate both high voltage sources for generating a pulsed DC voltage at the respective active electrode assembly, and in the working phase deactivate the high voltage source of the active electrode assembly that is not needed, and switch from pulsed DC voltage to non-pulsed DC voltage for the required active electrode assembly, and
keep both high voltage sources deactivated during the learning phase and in the working phase activate the high voltage source of the required electrode assembly.

2. The antistatic device according to claim 1 , wherein
the controller is at least one of configured and programmed to switch between at least a learning phase, during which the positive high voltage source and the negative high voltage source are activated, and a working phase, in which only one of the high voltage sources is active, and wherein
the sensor system is at least one of configured and programmed to monitor the currents flowing out of the respective high voltage source in order to detect the polarity of the neutralization current.

3. The antistatic device according to claim 1 , wherein
the sensor system is configured to measure the neutralising current from the respectively activated active electrode assembly, and the
controller is configured for controlling the high voltage sources, and
wherein the controller is coupled to the sensor system and is at least one of programmed and configured to switch automatically between two operating modes of the antistatic device depending on the measured neutralisation current.

4. The antistatic device according to claim 1 , wherein
the sensor system is configured to measure a quiescent current of at least one of the two active electrode assemblies and of the sensor electrode assembly,
the controller is configured for controlling the high voltage sources,
wherein the controller is coupled to the sensor system and is at least one of programmed and configured to evaluate the measured quiescent current for detecting at least one of electrode abrasion and contamination, and
wherein the controller performs the measurement and evaluation of the quiescent current during a diagnostic phase which is carried out during start-up of the material web.

5. The antistatic device according to claim 1 , wherein the active positive and negative electrode assemblies are arranged one of in and on a common electrode carrier.

6. The antistatic device according to claim 1 , wherein the sensor electrode assembly is arranged one of in and on the common electrode carrier.

7. The antistatic device according to claim 5 , wherein the common electrode carrier includes terminals for the high voltage sources and the sensor system.

8. The antistatic device according to claim 5 , wherein the common electrode carrier includes a partition wall located between the active electrode assemblies and the sensor electrode assembly, wherein the partition wall is designed to be at least one of electrically insulating and the partition wall projects beyond the electrodes in the direction of material web.

9. The antistatic device according to claim 7 , wherein the common electrode carrier includes at least one high voltage conductor electrically connected to at least one respective terminal.

10. The antistatic device according to claim 1 , wherein at least one of:
the sensor electrodes are arranged side by side in a straight sensor electrode row,
the positive electrodes are arranged side by side in a straight positive electrode row,
the negative electrodes are arranged side by side in a straight negative electrode row,
the positive electrodes and the negative electrodes are arranged side by side in a common straight electrode row in an alternating sequence, and
the sensor electrodes, the positive electrodes, and the negative electrodes are arranged side by side in a common straight electrode row in an alternating sequence.

11. The antistatic device according to claim 1 , wherein at least one of:
at least one positive electrode is disposed on a carrier foil on which at least one of a series resistor of said positive electrodes are imprinted,
at least one negative electrode is disposed on the carrier foil on which at least one of a series resistor of the negative electrodes are imprinted,
at least on of a series resistor of the sensor electrodes are imprinted,
the positive electrodes and the negative electrodes are disposed on a common carrier foil, on which the series resistors of the positive electrodes and the negative electrodes are imprinted, and
the sensor electrodes, the positive electrodes and the negative electrodes are disposed on the common carrier foil, on which the series resistors of the sensor electrodes, the series resistors of the positive electrodes, and the series resistors of the negative electrodes are imprinted.

12. The antistatic device according to claim 11 , wherein
the carrier foil is at least one of:
prepared together with the electrodes and the series resistors in a continuous strip material,
furnished with series resistors on both sides thereof, and
consists of a flexible material.

13. A method for operating an antistatic device for reducing electrostatic charge on a moving web of material, comprising: activing a positive electrode assembly and a negative electrode assembly, in which a polarity of the moving material web is determined via a sensor system, and wherein the positive and negative electrode assembly requ

Assignees

• Domschat Klaus
• Trimborn Christian W
• Goepfrich Armin
• Gema Switzerland Gmbh

Inventors

• Domschat Klaus
• Trimborn Christian W
• Goepfrich Armin

Classifications

• B65H26/02

  responsive to presence of irregularities in running webs · CPC title

• H01T19/04

  having pointed electrodes · CPC title

• H01T23/00 Primary

  Apparatus for generating ions to be introduced into non-enclosed gases, e.g. into the atmosphere · CPC title

• B41F13/02

  Conveying or guiding webs through presses or machines · CPC title

• B65H2515/716

  Operations & Transport · mapped topic