EP3553002B1 - Winding machine for web materials and method for operating such a winding machine - Google Patents

Description

The invention relates to a winding machine for web-like materials, in particular film materials, and a method for operating such a winding machine. The winding machine according to the invention is designed in particular as a so-called turret winder which, for the continuous winding of a material web, has at least a second position for removing a finished roll in addition to the winding position. Such a winding machine can also work inline with a production system with which a complete web of material is produced.

For example, from the publication JP 2002 020004 A a film winding machine is known, in which two laterally arranged drive shafts are provided for receiving a respective winding tube for winding two film webs onto two coaxially arranged winding tubes.

The document EP 1 451 087 A1 relates to a device for continuously winding webs onto winding shafts to form winding rolls, the device known from this prior art comprising arms supporting the winding shaft, a pressure roller which can be set against the winding shaft or winding sleeve, a pressure roller which The separating knife that cuts through the web when the roll is changed and consists of a charging electrode that provides the beginning of the web with an electrostatic charge and that fixes the new beginning of the web formed by the separating cut on the winding shaft. In order to always keep the charging electrode at the correct distance from the track provided with the charge, it is tracked in such a way that the distance between the charging electrode and the track remains constant, regardless of the diameter of the winding shaft.

The document GB 1 429 821 A discloses a winding machine for web-like materials with a feed device and at least one winding shaft, which can be driven and is designed to hold a winding sleeve for winding up the web-like material, the winding machine known from this prior art having a system for adjusting and/or reducing an electrostatic charge on the web-like material is associated with the winding process.

The document EP 1 807 333 A1 relates to devices for transporting webs of material and for fixing them on a counter-surface. The devices known from this prior art contain the following features: at least one transport roller for transporting the material webs and means for applying an electrostatic charge to at least parts of the material web, the electrostatic forces of which contribute to fixing these parts on a counter-surface. In particular, it is provided in this connection that at least one transport roller comprises means for applying an electrostatic charge to at least parts of the material web.

The present invention is based on the problem that currently existing winding machines are only suitable to a limited extent—if at all—for winding battery separator films without there being a risk of these separator films being damaged or being devalued in terms of quality.

According to the invention, this object is achieved by the subject matter of independent patent claim 1 and the method according to independent patent claim 11 .

The present invention is based on the finding that in the processing of high-quality battery separator films in particular electrostatic charging of the films is usually unavoidable. The build-up of such an electrostatic charge usually results in a corresponding electrostatic discharge, releasing large energies, particularly electrical ones. This can happen, for example, in the form of sparks or high electrical currents that flow briefly. Such a discharge poses a risk and can in particular damage the electrostatically charged or discharged film material and possibly at least partially destroy it.

For this reason, according to the invention, a winding machine for web-like materials, in particular foil materials, such as battery separator foils, is specified, the winding machine having a feed device and at least one winding shaft which can be driven and is designed to accommodate a winding sleeve for winding up the web-like foil material. In addition, the winding machine is assigned a system for adjusting and/or reducing an electrostatic charge on the web-like material during the winding process.

With the help of this system, the electrostatic charging of the film material can be effectively adjusted or reduced during the winding process, so that an electrostatic discharge that damages the film material can be effectively prevented.

The solution according to the invention is characterized in particular by the fact that the electrostatic charging of the film material can be adjusted with a particularly compact system, which significantly reduces the costs and the space requirement on the winding machine. The system can be implemented in a particularly compact manner insofar as several functions are assigned to the individual components of the system. Thus, the system for adjusting and/or reducing an electrostatic charge on the web-shaped material is, in particular, an electrostatic charge Running discharge / charging device, which is designed, if necessary, to electrostatically discharge the web-shaped material wound onto the winding sleeve accommodated by the at least one winding shaft.

The electrostatic discharge/charge device can have an active positive electrode arrangement which has a plurality of active needle-shaped individual positive electrodes and which is electrically connected to a positive high-voltage source during operation of the electrostatic discharge/charge device. Furthermore, the electrostatic discharging/charging device can have an active negative electrode arrangement which has at least two active needle-shaped individual negative electrodes and which is electrically connected to a negative high-voltage source during operation of the discharging/charging device. In addition, the electrostatic discharging/charging device can have a sensor electrode arrangement which has at least two needle-shaped individual sensor electrodes and which is electrically connected to a ground when the discharging/charging device is in operation.

According to embodiments of the invention, the electrostatic discharging/charging device can also be part of a feed unit which is designed to place a new start of web material on an empty winding core received by the at least one winding shaft and/or which is designed to place an end of web material on a finished wound one To let the winding sleeve adhere electrostatically.

According to embodiments of the winding machine according to the invention, the system for adjusting and/or reducing the electrostatic charge has an electrostatic discharge system assigned to the feed device of the winding machine, which serves and is designed to electrostatically discharge the web-shaped film material to be fed on the winding shaft of the winding machine.

According to embodiments, the winding machine according to the invention also has a contact roller unit in order to feed the web-like material to a winding core received by the at least one winding shaft at a winding point. It is advantageous here if the electrostatic discharge system associated with the feed device is arranged upstream of the contact roller unit—seen in the transport direction of the web-like material.

A sensor system is advantageously assigned to the electrostatic discharge system assigned to the feed device, via which the amount of an electrostatic charge and/or a polarity of an electrostatic charge of the web-shaped film material can be detected in order to be able to control the electrostatic discharge system assigned to the feed device accordingly. In this context, it is conceivable if the system for adjusting and/or reducing the electrostatic charge has a device for detecting the amount of an electrostatic charge and/or a polarity of an electrostatic charge on the web-shaped film material. This device is preferably a component of the electrostatic discharge system.

In this context, it is particularly conceivable if the electrostatic discharge system has an active positive electrode arrangement which has a plurality of active needle-shaped individual positive electrodes and which is connected to a positive high-voltage source during operation of the electrostatic discharge system, and an active negative electrode arrangement which has at least two active needle-shaped individual Has negative electrodes, and which is electrically connected to a negative high voltage source during operation of the electrostatic discharge system. In this embodiment, for example, the device for detecting the amount of an electrostatic charge and/or a polarity of an electrostatic charge on the web-shaped film material can have a sensor electrode arrangement which has at least two needle-shaped individual sensor electrodes and which is electrically connected to a ground during operation of the electrostatic discharge system .

As already indicated at the outset, the winding machine according to the invention is designed in particular as a turret winder and has at least two winding shafts, which can each be driven and are designed to accommodate a winding sleeve. It is conceivable if the winding shafts with the winding cores received can be transferred between a winding position for winding the material web onto a winding core received by a winding shaft and an unloading or loading position for removing a completely wound winding core or for feeding in an empty winding core.

In this context, it is particularly useful if the winding machine also has a cross-cutting device for cutting through the web-like material during or at the end of a winding process and/or during or at the beginning of a turning process, with the cross-cutting device relative to the winding core held by the at least one winding shaft is movable, in particular movable or pivotable. In particular, the cross-cutting device is assigned a feed device which is designed to place a new start of web material on an empty winding core accommodated by the at least one winding shaft, with the feed device having an electrostatic discharge/charge device belonging to the system for adjusting and/or reducing an electrostatic charge assigned.

According to embodiments, the electrostatic discharging/charging device of the system device is also designed, if necessary, to electrostatically discharge the web-like material wound onto the winding sleeve accommodated by the at least one winding shaft.

As an alternative or in addition to this, it is conceivable if an electrostatic discharge/charging device belonging to the system for adjusting and/or reducing an electrostatic charge is provided, which is designed to electrostatically charge a web material end in such a way that it adheres to the corresponding finished roll.

According to a preferred implementation of the winding machine or the system assigned to the winding machine for setting and/or reducing an electrostatic charge, it is provided that the electrostatic discharge/charge device of the system device has an active positive electrode arrangement, an active negative electrode arrangement and a sensor electrode arrangement. The active positive electrode arrangement has a plurality of active needle-shaped individual positive electrodes which are electrically connected to a positive high-voltage source during operation of the discharging/charging device. The active negative electrode arrangement of the electrostatic discharge/charge device has a plurality of active, needle-shaped individual negative electrodes which are electrically connected to a negative high-voltage source during operation of the discharge/charge device. The sensor electron arrangement has a plurality of needle-shaped individual sensor electrodes which are electrically connected to a ground when the discharging/charging device is in operation.

According to the invention, the winding machine according to the invention has a control device which is assigned to the system for setting and/or reducing an electrostatic charge. The control device is designed in particular to control the electrostatic discharge system assigned to the feed device and/or the electrostatic discharge/charge device assigned to the cross-cutting device during a winding process in such a way that electrostatic charging on the web-like material is at least reduced.

According to a further development of this, the control device is also designed, after the web-like material has been severed with the aid of the cross-cutting device, to control the electrostatic charging/discharging device assigned to the cross-cutting device in such a way that a new start of web material is electrostatically charged in order to attach the new start of web material to one of the at least one To create winding shaft recorded and preferably grounded empty winding core.

An exemplary embodiment of the winding machine according to the invention is described in more detail below with reference to the accompanying drawings.

FIG. 1

schematisch den Aufbau einer exemplarischen Ausführungsform der erfindungsgemäßen Wickelmaschine;

FIG. 2

eine stark vereinfachte Ansicht einer exemplarischen Ausführungsform des bei der erfindungsgemäßen Wickelmaschine zum Einsatzkommenden Systems zum Einstellen und/oder Reduzieren einer elektrostatischen Aufladung des bahnförmigen Materials;

FIG. 3

schematisch ein Blockschaltbild des Systems zum Einstellen und/ oder Reduzieren einer elektrostatischen Aufladung;

FIG. 4

schematisch ein Spannung-Zeit-Diagramm zur Veranschaulichung unterschiedlicher Betriebsphasen des Systems zum Einstellen und/ oder Reduzieren einer elektrostatischen Aufladung; und

FIG. 5

Schematisch in einer isometrischen Ansicht einen Elektrodenträger des Systems zum Einstellen und/oder Reduzieren einer elektrostatischen Aufladung.

It shows:

FIG. 1

schematically shows the structure of an exemplary embodiment of the winding machine according to the invention;

FIG. 2

a highly simplified view of an exemplary embodiment of the system used in the winding machine according to the invention for adjusting and/or reducing an electrostatic charge on the web-like material;

FIG. 3

a schematic block diagram of the system for adjusting and/or reducing an electrostatic charge;

FIG. 4

a schematic voltage-time diagram to illustrate different operating phases of the system for adjusting and/or reducing an electrostatic charge; and

FIG. 5

Schematically in an isometric view an electrode carrier of the system for adjusting and/or reducing an electrostatic charge.

An exemplary embodiment of the winding machine according to the invention is shown schematically in FIG. 1 shown. The winding machine is used for winding or winding up a web-like material, in particular film material, so that this is then in the form of a roll. For this purpose, the winding machine has a machine frame on which the individual components and units, which are described in particular below, are fastened or mounted.

A subassembly of the winding machine, referred to as a feed device, is used to feed in the web-like material. The feed device has a series of rollers that are not specified in detail. These are used to deflect the web-like material that is fed into the upper area of the winding machine.

This feeding to the winding machine can take place, for example, directly from a production plant or also from prefabricated rolls of the web-like material, which are to be rewound, for example, into smaller units in the form of smaller rolls or rolls. The material feed can also contain measuring devices or clamping devices, for example.

At the in FIG. 1 The winding machine shown schematically is a so-called "turret winder". This is used for the continuous winding of the web-like material and, in addition to the winding position, has at least a second position for removing the finished roll. For this is at the in FIG. 1 schematically illustrated winding machine is provided as a turning frame with two winding shafts (of course, a higher number of winding shafts can also be provided). This bogie is designed like a revolver. The two winding shafts are distributed at an angle of 180° in the vicinity of the outer circumference of the bogie.

The winding shafts each accommodate one winding sleeve. The web-like material is wound onto these winding cores by means of the winding machine. For this purpose, the winding shafts are designed to be drivable. In fact, a common or a separate drive can be provided for each of the winding shafts.

The winding sleeves positioned on the winding shafts are detachable for this purpose, but are connected to the winding shafts in a rotationally fixed manner. For example, the winding sleeves can be slipped onto the winding shafts and clamped there by corresponding clamping elements of the winding shafts. For this purpose, the winding shafts can have corresponding tensioning elements that allow a variation of the outer cross section of the respective winding shaft. The winding shafts can thus be expanded inside the winding sleeves and thus braced. As an alternative or in addition to this, suitable engaging elements can also be provided on the winding sleeves and the winding shafts, for example in the form of teeth.

In the representation in FIG. 1 the left-hand position of the winding shaft, at which a corresponding winding of the web-like material takes place, is also referred to as the "winding point" or "winding position". On the other hand, the right-hand position of the winding shaft is the "removal point" or "removal position" in which a more or less filled winding tube can be removed and an empty winding tube can be attached to the winding shaft.

In order to be able to bring the bogie and in particular a winding tube into a corresponding position for feeding, winding or removing a winding tube at the corresponding positions, the bogie is driven. For this purpose, it is equipped with a ring gear on the outermost circumference of the lateral spur gears. A corresponding gearwheel of a drive meshes with this ring gear. With this, the bogie can be rotated around a central, horizontal axis of rotation. Thus, the two winding shafts can each be moved or pivoted from one position to the next.

The actual feeding of the web-like material to the respective core to be wound is carried out by means of a contact roller unit. For this purpose, the contact roller unit takes over the web-shaped material from the feed device. The web-like material is then fed to the winding core at the winding point by means of corresponding rollers of the contact roller unit. This can happen with free-running web material, especially when starting up the winding machine. In production operation, however, the contact roller unit is brought up to the winding core with the web-like material already wound up on it in such a way that an optimal winding result is achieved by pressing using a pressure roller or compact roller. In this case, optimization is carried out in particular with regard to a smooth positioning of the layers on one another on the one hand and a reduction in the air inclusion between the layers on the other.

To further optimize the winding result, the exemplary embodiment of the winding machine according to the invention has a system for adjusting and/or reducing an electrostatic charge on the web-like material during the winding process, which is described in more detail below.

This system includes, on the one hand, an electrostatic discharge system assigned to the feed device, which serves to electrostatically discharge the web-like material to be fed to the winding shaft at the winding point. At the in FIG. 1 shown embodiment of the winding machine according to the invention, this electrostatic discharge system is arranged above the web-like material and thus serves to electrostatically discharge the upper side of the web-like material.

Furthermore, a suitable sensor system is provided in order to provide an amount of electrostatic charging and/or a polarity of an electrostatic charging of the web-shaped material. At the in FIG. 1 Schematically illustrated embodiment of the winding machine according to the invention, the sensor system is preferably designed in the form of a sensor electrode arrangement which has at least two needle-shaped individual sensor electrodes and which is electrically connected to ground during operation of the electrostatic discharge system.

Advantageously, the electrostatic charging of the web-like material is detected with this sensor system and the electrostatic discharge system associated with the feed device is suitably controlled, preferably with the aid of a control circuit, in order to minimize the electrostatic charging of the web-like material.

For example, when changing the winding sleeves or the resulting roll of web-like material (the so-called finished roll), the web-like material has to be severed. In order to be able to do this during operation, a cross-cutting device is provided. Like the contact roller unit, this cross-cutting device is movably mounted within the machine frame by means of a separate rail system. As an alternative or in addition to this, it is conceivable if the transverse cutting device is also designed to be pivotable relative to the winding shaft at the winding point.

A corresponding cutting head is preferably provided on the transverse cutting device in a height-adjustable manner. With the help of this cutting head, the web-shaped material can be severed transversely to the web length during operation. The severing typically takes place in the area of the contact roller unit, since the web-like material is held securely in the contact roller unit in this area, so that the severing can take place smoothly with the aid of the cutting head of the cross-cutting device. For this purpose, the transverse cutting device with the cutting head can have a cutting roller or a knife roller which carries a knife. This blade is typically designed as a serrated blade extending along the blade cylinder.

Both the contact roller unit and the cross cutting device are—as already indicated—movably mounted on corresponding rail systems. In particular, this enables a linear movement along the rail systems. A separate drive is usually provided for each of these units.

To remove a core that is typically filled with web material up to a predefined degree of filling or core diameter from the reeling machine, an in FIG. 1 roller table not shown in detail serve.

In the case of a flying roll change or when the winding machine is started up, a starting area of the web-like material (starting web material) is wound onto a first winding core. For this purpose, it may first be necessary to fasten it to the winding core, which is done according to the present invention by electrostatic forces. The winding process is then started by rotating the winding shaft with the winding core arranged on it. If necessary, the contact roller of the contact roller unit can be moved towards the winding tube for this purpose in order to press the web-like material.

To apply a new web material start to an empty winding core picked up by the corresponding winding shaft at the winding point, a corresponding contact device is used, which has an electrostatic discharge/charge device belonging to the system for adjusting and/or reducing an electrostatic charge. This electrostatic discharge/charging device is used not only to place the beginning of the new web material on the new empty winding core during a flying roll change, but also, if necessary, to electrostatically discharge the web-like material wound onto the winding core accommodated by the at least one winding shaft.

Alternatively or additionally, it is conceivable if the electrostatic discharge/charge device belonging to the system for adjusting and/or reducing an electrostatic charge is designed to electrostatically charge a web material end in such a way that it adheres to the corresponding finished roll.

More specifically, the discharging/charging device preferably has an electrode unit in which a plurality of electrodes are arranged opposite to the web-shaped material to be statically discharged. The electrodes can be individual electrodes. However, as illustrated, a plurality of electrodes may be arranged in the direction of travel of the sheet material to be static-eliminated or in a direction perpendicular thereto.

The electrode is constructed such that a pair of electrode needles face each other in a holding member made of insulating material, and positive and negative voltages are individually applied to the electrode needles. For this purpose, the electrode needles are each connected to a voltage supply. A controller to be described later controls such that, for example, a high positive voltage is supplied to a first electrode needle of the electrode needles, and a high negative voltage of reverse polarity thereto is supplied to a second electrode needle. Typically, a high voltage is applied to one of the electrode needles and the other electrode needle is connected to ground. The electrode needle connected to ground is connected to the same ground level as the machine frame of the winding machine.

An air discharge port may be provided between the pair of electrode needles for blowing out an air stream against the sheet material to be static-discharged. The air outlet opening is connected to a blower or the like, not shown, for blowing out an air stream. If such an air discharge port is provided, the positive or negative ions generated between the pair of electrode needles can be guided by the air flow from one air discharge port to the vicinity of the sheet material to be static-eliminated, thereby achieving static elimination with a high efficiency.

The electrostatic discharging/charging device further includes a sensor provided in the vicinity of the sheet material to be static-discharged and for detecting the charge polarity and the charge amount based on a surface potential of the sheet material to be static-discharged. The sensor is connected to the controller to control the voltages applied to the electrode needles based on the output of the sensor.

According to one embodiment, the control device controls a switching to be carried out in a short time interval between a supply status in which one of the electrode needles is supplied with a high positive or negative voltage and the other electrode needle is connected to ground, and a supply status in which the electrode needle, the is supplied with the high voltage is connected to the ground and the electrode needle connected to the ground is supplied with a high voltage of an opposite polarity to the high voltage of the other electrode needle. Switching can take place, for example, in the range of several Hertz, such as 33 Hertz or 22 Hertz. In this case the sensor would not be necessary.

When the high voltage to be applied to the electrode needles is controlled by using the controller, the positive and negative ions act on the sheet material to be static-eliminated. Of these ions, only the ions having the opposite polarity to the charge polarity of the sheet material to be static-discharged are absorbed by the material to efficiently discharge the static. Although the static discharge speed is slightly slower than in the case of the second discharger/charger to be described later, efficient static discharge can be achieved without reverse polarity charging.

If, on the other hand, in the alternative embodiment of the electrostatic discharge/charging device, the charge amount of the web-shaped material to be statically discharged, which is detected by the sensor, exceeds a predetermined value, the control device leads the electrode needle, which is charged with a high voltage with a charge polarity of the web-shaped material of opposite polarity, applies a high voltage and connects the other electrode needle to ground to generate positive or negative ions for static discharge based on the high voltage of the electrode needle. As a result of the ion static discharge, when the sensor detects that the charge amount is at or below the threshold value, the controller controls the voltage supply so that the supply of the high voltage is stopped.

If, on the other hand, the unloading/charging device has to take over the function of the contact device during a flying roll change, the control device controls the electrode needles in such a way that the web material is electrostatically charged and the start of the web material thus adheres electrostatically to the new empty winding core, which is preferably grounded , to allow.

The sequence of an automatic turning process in the exemplary embodiment of the winding machine according to the invention is briefly summarized below. First, the web-like material is rolled up at the winding point from the winding tube to a maximum diameter. During this phase, the electrostatic discharge system assigned to the feed device of the winding machine is activated in order to electrostatically discharge the web-shaped material to be fed to the winding shaft. In addition, the electrostatic discharging/charging device assigned to the cross-cutting device is activated. For this purpose, the corresponding cutting arm with the unloading/charging device is moved relative to the winding shaft at the winding point.

When the maximum diameter of the first core is reached, it is transferred to the removal point or removal position, the web-shaped material now runs further over the second core and is further rolled onto the first core. The cutting arm of the cross-cutting device then swivels up to approx. 30 mm to the first winding core, which is in the removal position, in order to cut through the web-shaped material. The web-like material is guided upwards by a guide roller at the end of the swivel arm of the cross-cutting device.

At this point in time, the electrostatic discharge/charging device, which is assigned to the cross-cutting device, is activated in such a way that it takes over its function as a contact device. The activation takes place, for example, for a period of 5 to 15 seconds and serves the purpose that the new beginning of the web material adheres to the new (second) empty winding tube, which is in the winding position.

A significant advantage of the system provided in the winding machine according to the invention for adjusting and/or reducing an electrostatic charge of the web-like material during the winding process is that the electrostatic discharge/charge device, which is assigned to the cross-cutting device, has the double function described above, so that the overall costs of the system can be significantly reduced.

In addition, the winding result can be significantly optimized with the help of the system, especially when foil material is used as web material, such as separator foils for lithium-ion batteries.

In FIG. 2 is a highly simplified example of an exemplary embodiment of a system for adjusting and/or reducing an electrostatic charge on the web-like material, this system being used in a winding machine, in particular the one previously referred to with reference to the illustration in FIG. 1 shown winding machine is used. As shown, the web-like material 2 is moved in a direction of movement 3, with the system for adjusting and/or reducing an electrostatic charge being able to selectively reduce and preferably eliminate an electrostatic charge on the material web 2 . The system is also referred to below as "antistatic device 4".

Purely as an example are in FIG. 2 five positive charge units 5 are indicated on the material web 2 with respect to the direction of movement 3 in front of the antistatic device 4, which the material web 2 carries with it for production reasons. Five negative charge units 6 are indicated in the area of the antistatic device 4 , which are generated with the aid of the antistatic device 4 and cause the five positive charge units 5 to be neutralized. in FIG. 2 In the ideal case shown, the material web 2 is charge-free or charge-neutral with respect to its direction of movement 3 after the antistatic device 4 . In this charge-free or charge-neutral state, the material web 2 is fed, for example, to the winding tube received by the at least one winding shaft of the winding machine.

According to the schematic block diagram of the antistatic device 4 according to FIG. 3 the antistatic device 4 comprises an active positive electrode arrangement 7, an active negative electrode arrangement 8 and a sensor electrode arrangement 9. The positive electrode arrangement 7 has a plurality of active needle-shaped individual positive electrodes 10, which in FIG. 3 in each case a series resistor 11 is assigned, and which are electrically connected to a positive high-voltage source 12. The negative electrode arrangement 8 has a plurality of active, needle-shaped individual negative electrodes 13, which, as shown in FIG FIG. 3 a series resistor 14 is assigned in each case, and which are electrically connected to a negative high-voltage source 15 .

The sensor electrode arrangement 9 comprises a plurality of needle-shaped individual sensor electrodes 16, in which FIG. 3 individual series resistors 17 are assigned, and which are electrically connected to a ground 19. The ground 19 is normally a ground. The positive electrode arrangement 7 and the negative electrode arrangement 8 can also be referred to as ionization electrode arrangements 7, 8.

A controller 18 cooperates with a sensor system 20, with the aid of which a polarity of a neutralization current of the sensor electrode arrangement 9 can be detected during the operation of the antistatic device 4. The controller 18 serves to control the high-voltage sources 12, 15 and is coupled to the sensor system 20 in a suitable manner. In the example, the sensors 20 are integrated into the controller 18 .

The controller 18 can contain a corresponding microprocessor 21 for evaluating the signals determined with the aid of the sensor system 20 or for driving the high-voltage sources 12, 15.

According to the block diagram FIG. 3 several measuring resistors 22 can also be seen, via which the electrode arrangements 7, 8, 9 and the high-voltage sources 12, 15 are connected to the ground 19, with parallel sensor lines 23 being routed to the controller 18 or to the sensors 20, which via their grounding 19 currents flowing.

The polarity of the charge on the material web 3 can thus be detected via the sensor system 20 in connection with the sensor electrode arrangement 9 via the polarity of the neutralization current of the sensor electrode arrangement 9 . Since the sensor electrodes 16 are connected to ground 19 via their series resistors 17 and the measuring resistor 22, the sensor electrode arrangement 9 works like a passive neutralization electrode arrangement, whereby a neutralization current flows when the material web 2 is charged accordingly.

By determining the polarity of the neutralization current, the polarity of the charge on the material web 2 can be detected. Depending on the polarity determined, the controller 18 can now deactivate the active electrode arrangement 7, 8 that is not required in each case. For example, the polarity of the neutralization current of the sensor electrode arrangement 9 can be negative, which speaks for a negative charge on the material web 2 . As a result, the controller 18 activates the positive high-voltage source 12 and thus the positive electrode arrangement 7. At the same time, the negative high-voltage source 15 and thus the negative electrode arrangement 8 are deactivated.

However, if it is established that the neutralization current of the sensor electrode arrangement 9 is positive, this indicates that the material web 2 has a positive charge. As a result, the controller 18 deactivates the positive high-voltage source 12 and thus deactivates the positive electrode arrangement 7, while at the same time the negative high-voltage source 15 is activated and the negative electrode arrangement 8 is activated.

The controller 18 preferably controls the activated high-voltage source 12 or 15 at least during a working phase so that at the respective active electrode arrangement 7, 8 an unpulsed DC voltage is present, which is preferably also constant.

With reference to the voltage-time diagram according to FIG. 4 an advantageous procedure that can be implemented with the aid of the controller 18 is explained in more detail. For this purpose, the controller 18 is configured or programmed accordingly. in the in FIG. 4 In the diagram shown, the abscissa defines a time axis t, while the ordinate indicates the voltage U across the active electrode arrangements 7, 8. The voltage curve of the positive electrode arrangement 7 is found in the positive section of the ordinate, while the voltage curve of the negative electrode arrangement 8 is reproduced in the negative section of the ordinate.

The time axis t is divided into a learning phase 24 and a working phase 25. During the learning phase 24, which begins at a point in time t0, the controller 18 causes the positive high-voltage source 12 to supply the positive electrode arrangement 7 with positive voltage pulses 26, for example. At the same time, the negative electrode arrangement 8 is supplied with negative voltage pulses 27 by the negative high-voltage source 15 . The positive voltage pulses 26 and the negative voltage pulses 27 are expediently phase-shifted relative to one another in time to such an extent that a type of square-wave AC voltage is present across both active electrode arrangements 7 , 8 . In other words, the positive voltage pulses 26 are positioned at the same time as gaps 28 that lie between adjacent negative voltage pulses 27 . Conversely, the negative voltage pulses 27 are also positioned in such a way that they are positioned at the same time as gaps 29 between adjacent positive voltage pulses 26 .

During the learning phase 24, the controller 18, in conjunction with the sensor system 20, determines the polarity of the neutralization current of the sensor electrode arrangement 9.

In the example of FIG. 4 a positive polarity is determined, so that the learning phase 24 changes to the working phase 25 at a point in time t1.

In the working phase 25, if the polarity of the neutralization current of the sensor electrode arrangement 9 is positive, the positive high-voltage source 12 is deactivated, so that no voltage is supplied to the positive electrode arrangement 7 more available. At the same time, the negative high-voltage source 15 is controlled in such a way that it generates an unpulsed negative DC voltage 30 from said point in time t1.

In another embodiment it can be provided that during the learning phase 24 both ionization electrode arrangements 7, 8 are deactivated. As soon as a neutralization current with a stable polarity can be determined via the sensor electrode arrangement 9, the ionization electrode arrangement 7, 8 required in each case can then be activated via the controller 18.

During this working phase 25, for example, the neutralization current of the respectively active electrode arrangement 7, 8 can be monitored permanently. In the example of FIG. 4 the neutralization current of the activated negative electrode arrangement 8 is thus monitored in the working phase 25 . If irregularities or predetermined events occur within this neutralization flow, the controller 18 can switch from the current operating mode to another operating mode. The controller 18 expediently changes from the working phase 25 back to the learning phase 24, in which both high-voltage sources 12, 15 are active and expediently apply pulsed DC voltage 26, 27 to the two active electrode arrangements 7, 8.

At the same time or alternatively, a degree of electrode erosion and/or a degree of electrode contamination can also be monitored by measuring a quiescent current of the respective active electrode arrangement 7, 8 and/or the sensor electrode arrangement 9.

The quiescent current is expediently monitored during a diagnosis phase, which is active or switched on each time, for example, the material web 2 is approached, for example after a material web change. When the material web 2 is approaching or when the material web 2 is stationary, no or only a very small amount of static charging can occur, so that in particular no ion currents from one of the active ionization electrodes 7, 8 to the material web are produced. The same applies to the passive sensor electrode arrangement 9.

On the other hand, ion currents occur between the negative electrode arrangement 8 and the positive electrode arrangement 7 and between the sensor electrode arrangement 9 and at least one of the ionization electrode arrangements 7, 8 via the air. These quiescent currents vary significantly depending on dirt and also correlate with the erosion of the electrodes 10, 13, 16 or with the erosion of the tips of the electrodes 10, 13, 16.

According to the representation in FIG. 5 the positive electrode arrangement 7, the negative electrode arrangement 8 and the sensor electrode arrangement 9 can be arranged in or on a common electrode carrier 31. The electrode carrier 31 then has a positive connection 32 for connecting the positive electrode arrangement 7 to the positive high-voltage source 12, a negative connection 33 for connecting the negative electrode arrangement 8 to the negative high-voltage source 15 and a sensor connection 34 for connecting the sensor arrangement 9 to the sensor system 20.

In the embodiment according to FIG. 5 the electrode carrier 31 can have a partition 35, which can be configured in particular to be electrically insulating, and which extends between the two active electrode arrangements 7, 8 on the one hand and the sensor electrode arrangement 9 on the other hand. In this way, a short circuit via the air between the two active electrode arrangements 7, 8 and the passively operating sensor electrode arrangement 9 can be avoided. In order to improve this effect, the partition wall 35 can be designed in such a way that it protrudes in the direction of the material web 2 over the electrodes 10, 13, 16 or over their tips.

At the in FIG. 5 In the embodiment shown, the individual positive electrodes 10 are arranged in a straight row 36 of positive electrodes. The negative electrodes 13 are arranged in a straight row 37 of negative electrodes and the sensor electrodes 16 are arranged in a straight row 38 of sensor electrodes. Thus shows FIG. 5 an embodiment with three separate rows of electrodes 36, 37, 38, which in the mounted state the antistatic device 4 are positioned one behind the other with respect to the direction of movement 3 of the material web 2, the rows 36, 37, 38 then extending transversely to the direction of movement 3.

The invention relates not only to a winding machine as described above by way of example with reference to the drawings, but also to a corresponding method for operating a winding machine, in particular such a winding machine.

Furthermore, the invention is not limited to the exemplary embodiment, but is in all the features disclosed herein as defined by the appended claims.

Claims (11)

1. A winding machine for web-type materials, in particular film materials, comprising a feeding device and at least one winding shaft which is capable of being driven and designed to receive a winding core for winding the web-type material, wherein the winding machine is allocated a system for regulating and/or reducing an electrostatic charge of the web-type material during the winding process,

   wherein a control device allocated to the system for regulating and/or reducing an electrostatic charge is further provided, wherein the control device is designed to control the electrostatic discharge system allocated to the feeding device and/or the electrostatic discharging/charging device allocated to the cross-cutting device during a winding process such that an electrostatic charge on the web-type material is at least reduced,

   wherein the control device is further designed to control the electrostatic discharging/charging device allocated to the cross-cutting device subsequent to the cross-cutting device cutting through the web-type material such that a new start of the web-type material is electrostatically charged for the feeding of the new web-type material start onto an empty and preferably grounded winding core accommodated by the at least one winding shaft; and/or

   wherein the control device is further designed to control the electrostatic discharging/charging device allocated to the cross-cutting device subsequent to the cross-cutting device cutting through the web-type material such that an end of the web-type material is electrostatically charged for the feeding of the web-type material end onto a full and preferably grounded winding core accommodated by the at least one winding shaft.
2. The winding machine according to claim 1,
   wherein the system for regulating and/or reducing the electrostatic charge comprises an electrostatic discharge system allocated to the feeding device for the electrostatic discharging of the web-type material to be fed onto the winding core accommodated by the at least one winding shaft.
3. The winding machine according to claim 2,
   wherein the winding machine further comprises a contact roller unit for feeding the web-type material to a winding core accommodated by the at least one winding shaft at a winding point, wherein the electrostatic discharge system allocated to the feeding device is arranged - as seen in the web-type material's direction of transport - upstream of the contact roller unit.
4. The winding machine according to one of claims 1 to 3,
   wherein the system for regulating and/or reducing electrostatic charge comprises a device for detecting a magnitude of an electrostatic charge and/or a polarity of an electrostatic charge of the web-type material.
5. The winding machine according to claim 4,
   wherein the device for detecting an electrostatic charge magnitude and/or an electrostatic charge polarity is implemented as a component of the system for regulating and/or reducing an electrostatic charge of the web-type material, particularly in the form of a sensor electrode array having at least two needle-like individual sensor electrodes.
6. The winding machine according to one of claims 1 to 5,
   wherein the winding machine further comprises a cross-cutting device for cutting through the web-type material during or at the end of a winding process and/or during or at the start of a turning process, wherein the cross-cutting device is movable, in particular displaceable or pivotable, relative to the winding core accommodated by the at least one winding shaft.
7. The winding machine according to claim 6,
   wherein the cross-cutting device is allocated a contact device for feeding a new start of the web-type material onto an empty winding core accommodated by the at least one winding shaft, wherein the contact device comprises an electrostatic discharging/charging device constituting part of the system for regulating and/or reducing electrostatic charge.
8. The winding machine according to claim 7,
   wherein the electrostatic discharging/charging device of the contact device is designed to electrostatically discharge the web-type material wound onto the winding core accommodated by the at least one winding shaft when needed, wherein the electrostatic discharging/charging device comprises the following:

   - an active positive electrode array which comprises at least one and preferably a plurality of active needle-like individual positive electrodes and which is electrically connected to a positive high-voltage source during the operation of the electrostatic discharging/charging device;

   - an active negative electrode array which comprises at least two active needle-like individual negative electrodes and which is electrically connected to a negative high-voltage source during the operation of the discharging/charging device; and

   - a sensor electrode array which comprises at least two needle-like individual sensor electrodes and which is electrically connected to a ground during the operation of the discharging/charging device.
9. The winding machine according to claim 7 or 8,
   wherein the electrostatic discharging/charging device is allocated a sensor system for detecting the polarity of a neutralizing current of the sensor electrode array during the operation of the electrostatic discharging/ charging device.
10. The winding machine according to one of claims 1 to 9,
    wherein the winding machine is designed as a turret winder and comprises at least two winding shafts, each capable of being driven and designed to receive a winding core, wherein the winding shafts with the received winding cores can be conveyed between a winding position for winding the web-type material onto the winding core and an unloading/loading position for removing a fully wound winding core or respectively supplying an empty winding core.
11. A method for operating a winding machine according to one of claims 1 to 10, wherein the method comprises the following method steps,

    (a) the web-type material being rolled up to a maximum diameter of a first winding core, wherein the electrostatic discharge system allocated to the feeding device of the winding machine and the electrostatic discharging/charging device allocated to the cross-cutting device of the winding machine for reducing an electrostatic charge on the web-type material and the winding being activated during this phase;

    (b) the winding core being conveyed to the unloading/loading position upon reaching the maximum diameter, wherein the web-type material then runs over a winding core accommodated on a second winding shaft and is further rolled onto the first winding core;

    (c) the cross-cutting device being used to cut through the web-type material while the electrostatic discharging/charging device allocated to the cross-cutting device is simultaneously activated so as to electrostatically charge the web-type material and in particular the new start of the web material.

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