JP7044233B2 - Static elimination method and static elimination device - Google Patents

Description

The present invention relates to a static elimination method and an apparatus thereof for statically eliminating an object to be statically charged to the inside, such as a sheet charged by digital printing.

Conventionally, there is a printing system that prints on a sheet-shaped print target by using digital technology without making a printing plate (see Patent Document 1). Sheets printed by this type of printing press will be charged.
When the printed sheet is charged, there is no particular problem because the positive and negative charges on both sides form a closed electric field. However, when the charge is discharged from the printing machine and laminated on the tray T or the like, as shown in FIG. 4, the charges on both sides of the sheet 1 are not closed through the thickness of one sheet 1 but are laminated. Join between the upper and lower sheets 1 and 1. This is because the distance between the upper and lower sheets 1 and 1 in contact with each other is smaller than the thickness of the sheet 1.

Therefore, a strong suction force due to the Coulomb force is generated between the laminated sheets 1 and 1, and the sheets 1 and 1 stick to each other.
Although the thickness of the sheet 1 is shown large for the sake of explanation in FIG. 4, the thickness of the sheet 1 is actually about several tens [μm] to 1 [mm].
As a result, it becomes difficult to peel off the sheets 1 one by one, and there arises a problem that subsequent processes such as folding, cutting, and bookbinding do not proceed smoothly.
Therefore, it is necessary to provide a static elimination process in the post-process of digital printing.
As the static elimination method, a method of irradiating the surface of the sheet 1 with positive and negative ions generated by the corona discharge to neutralize the surface charge is often used.

International Publication No. 2016/013436 Japanese Unexamined Patent Publication No. 2008-004397

As described above, it has been conventionally known to provide a static elimination step as a post-process of digital printing, but when the charge amount of the sheet 1 is high or the charge is accumulated even inside the sheet 1, the above-mentioned With such existing static elimination methods, it takes a long time to eliminate static electricity, or it is not possible to completely eliminate static electricity.
In particular, in the case of a multilayer sheet, electric charges tend to accumulate at the boundaries between different materials, and it is difficult to eliminate the electric charges.

For example, as shown in FIG. 5, in the case where the sheet 1 is a multilayer composed of a paper layer 1a, an aluminum vapor deposition layer 1b, and a resin layer 1c, when the sheet 1 is charged to the inside under the influence of a strong electric field in a digital printing machine, the aluminum vapor deposition layer is charged. 1b is polarized and attracts electric charges of the upper and lower resin layers 1c and the paper layer 1a. It was difficult to eliminate such internal charges even if the surface was irradiated with ions.
Therefore, the amount of charge of the sheets 1 cannot be reduced, and if the sheets 1 in such a charged state are laminated, the sheets 1 will be electrostatically adsorbed to each other as shown in FIG.

In order to eliminate static electricity from such a sheet 1 that is difficult to eliminate static electricity, it is necessary to take time and effort such as repeating ion irradiation many times, and the processing efficiency has deteriorated.
Further, since the repeated static elimination process is provided, there is also a problem that the static elimination device becomes large.
As mentioned above, even if ion irradiation was repeated, in reality, perfect static elimination was hardly possible.

On the other hand, as a method of removing the electric charge that accumulates inside and is difficult to remove static electricity as described above, the ground electrode is brought close to the charged sheet 1 under a vacuum that is easily discharged, and the internal charge is transferred from the end face of the sheet 1 to the ground electrode. A method of discharging to is conceivable. Then, according to this method, not only the electric charge inside the sheet 1 charged at a high potential but also the electric charge on the surface can be eliminated.
However, when the total charge amount of the sheet 1 is very high, a large amount of electric charge flows at once between the sheet 1 and the ground electrode to generate an electric discharge, and even if the static elimination is possible, the sheet 1 is damaged by the electric discharge. Sometimes. Specifically, holes and cracks may be formed in the sheet 1.
An object of the present invention is to provide a static elimination method and a static elimination device capable of completely eliminating static electricity in a short time without damaging an object to be statically eliminated, such as a multilayer sheet in which electric charges tend to accumulate inside and it is difficult to eliminate static electricity. That is.

The first invention comprises a vacuum chamber, a transport means for transporting an object to be discharged in the vacuum chamber, an ion irradiation means for irradiating the object to be discharged with ions, and an object to be discharged more than the ion irradiation means. A discharge means provided on the downstream side in the transport direction is provided, and the ion irradiation means is composed of a pair of discharge electrodes arranged opposite to each other with a transport path of the static elimination object to be applied and to which a voltage of opposite polarity is applied. The pair of discharge electrodes are covered with an electrical insulating material except for the portions facing each other, and the discharge means is provided in contact with or close to the static elimination target to transfer the electric charge of the static elimination target to the ground side. It is configured to flow.

The second invention comprises a main chamber that realizes a vacuum, and at least one subchamber arranged in series on each of the upstream side and the downstream side of the main chamber with respect to the transport direction of the static elimination object. A transport means for transporting the static elimination target from the most upstream subchamber to the most downstream subchamber is provided, and the main chamber is provided with ions that irradiate the static elimination target transported in the main chamber with ions. An irradiation means and a discharge means provided downstream of the ion irradiation means in the transport direction of the static elimination target are provided, and the discharge means and the static elimination target are brought into contact with or close to each other to charge the charge of the static elimination target. The subchambers are configured to flow to the ground side, and vacuum realization means are connected to each of the subchambers, and supply ports and discharge ports for the static elimination target are provided to prevent outside air from entering the supply ports and discharge ports. However, a sealing mechanism that enables the movement of the static elimination target is provided .
The vacuum in the vacuum chamber is the degree of vacuum at which discharge is most likely to occur, and is, for example, a pressure of about 1 to 5000 [Pa].

In the third invention, the discharge means comprises a ground electrode that is in contact with or is in close proximity to the static elimination target in the transport path of the static elimination target.

In the fourth invention, the ground electrode constituting the discharge means is composed of a pair of grounding rollers that sandwich the static elimination object, and charges are flowed from the static elimination object passing between the pair of grounding rollers to the ground side. It is configured.

In the fifth invention, the pair of grounding rollers has a length equal to or longer than the width of the static elimination object.

In the sixth aspect of the invention, the outer peripheral portion of the pair of grounding rollers excluding the portion in contact with the transport path of the static elimination object is covered with an electric insulating material.

According to the present invention, the surface charge is neutralized by irradiating the ions generated in the vacuum chamber to reduce the charge amount of the entire static elimination object to some extent, and then the charge remaining by the discharge means is transferred to the ground side. It can be flushed and almost completely neutralized.
Moreover, since the total charge amount of the static elimination object is low due to the neutralization by ions before discharging by the discharge means, the amount of current flowing at once by the discharge is not so large, and the static elimination target is damaged by the discharge. There is no such thing.
In particular, since the inside of the vacuum chamber is easily discharged, many ions are generated in the ion irradiation step, and neutralization by ion irradiation is rapidly performed.
In addition, since the environment is such that discharge between the static elimination object and the discharge means is likely to occur, complete static elimination can be performed in a short time.
In particular, according to the first invention, the discharge between the facing discharge electrodes can be concentrated in the direction toward the static elimination target, and the ion generation region can correspond to the transport path of the static elimination target. Therefore, the generated ions are efficiently irradiated to the static elimination target.
Further, according to the second invention, since the static elimination object is supplied to the main chamber via the subchamber and discharged to the outside through the subchamber, the outside air is discharged from the most upstream supply port and the most downstream discharge port. Has little effect on the degree of vacuum in the main chamber. Therefore, the inside of the main chamber can be maintained at the optimum degree of vacuum for discharge.
In particular, the faster the transport speed of the static elimination object, the larger the amount of outside air invading from the supply port and the discharge port. You can increase the speed.

In the third invention, since the ground electrode is provided under vacuum, discharge from the static elimination object is likely to occur, and static elimination can be performed in a short time.

According to the fourth invention, since the ground roller, which is the ground electrode, rotates, the distance between the static elimination target and the ground electrode can be minimized by sandwiching the conveyed static elimination target. Since the distance between the static elimination object and the ground electrode is minimized, the static elimination effect is enhanced.
If the non-rotating ground electrode is brought into contact with the static elimination object under vacuum, the frictional resistance is too large to convey the static elimination target. On the other hand, if it is attempted to maintain a slight gap between the static elimination object to be conveyed and the ground electrode, it becomes difficult to manage the gap.
Therefore, a rotating ground roller is the most suitable as a discharge means for discharging the object to be statically removed while being conveyed.
In this way, static elimination can be performed while transporting the static elimination target, so that the static elimination processing speed increases.

According to the fifth invention, since the entire width of the static elimination object comes into contact with the grounding roller, discharge from the end face of the static elimination target is likely to occur, and the static elimination processing speed is increased.

According to the sixth invention, it is possible to prevent the ions generated by the ion irradiation means from being absorbed by the ground roller. Therefore, the generated ions are efficiently irradiated to the static elimination target, and the charged charge can be neutralized.
Further, if the grounding roller is exposed in the transport path of the static elimination object, the charged static elimination target may be attracted to and attached to the surface of the grounding roller by the electric charge. If the object to be statically eliminated sticks to the surface of the grounding roller, it cannot be sandwiched between the pair of grounding rollers, and transportation and static elimination may not be possible. However, according to the present invention, it is possible to prevent the static elimination object having the remaining electric charge from sticking to the grounding roller before being sandwiched between the grounding rollers.

It is a block diagram of the static elimination apparatus of embodiment of this invention. It is an enlarged view near the grounding roller of an embodiment. It is a partially enlarged view which showed the state which the sheet was sandwiched by the grounding roller of an embodiment. It is explanatory drawing which shows the state which the charged sheet is loaded on the tray. It is an end view of the charged multilayer sheet.

In one embodiment of the present invention shown in FIGS. 1 to 3, a multilayer sheet 1 as shown in FIG. 5 printed by a digital printing machine is supplied in the grounded metal chamber body 2 in the direction of the arrow x. It is a device that processes continuously.
The inside of the metal chamber body 2 is divided by partition walls 3 and 4, and the center thereof is the main chamber 5, which is the vacuum chamber of the present invention, the partition wall 3 side is the front chamber 6, and the partition wall 4 side is the rear chamber 7. There is. The front chamber 6 and the rear chamber 7 are subchambers of the present invention.
The inside of the main chamber 5 is exhausted by the vacuum pump P1 so that a vacuum degree of several hundred [Pa] is maintained.
Further, the inside of the front chamber 6 and the rear chamber 7 is exhausted by the vacuum pump P2 so that the degree of vacuum equal to or lower than that of the main chamber 5 is maintained.

In the center of the outer wall 8 of the front chamber side 6, an insulating member 10 made of an electrical insulating material such as a fluororesin extending in a direction orthogonal to the paper surface of FIG. 1 is fitted. The insulating member 10 is formed with a slit-shaped opening 10a through which the printed sheet 1 can pass. The opening 10a constitutes the supply port of the front chamber 6.
Further, the partition walls 3, 4 and the outer wall 9 are fitted with insulating members 11, 12, 13 having the same configuration as the insulating member 10, respectively, and openings 11a, 12a, 13a are formed in each.
The opening 11a provided in the partition wall 3 serves as both the discharge port of the front chamber 6 and the supply port of the main chamber 5, and the opening 12a provided in the partition wall 4 serves as the discharge port of the main chamber 5 and the supply port of the rear chamber 7. Also serves as a mouth. Further, the opening 13a of the outer wall 9 constitutes the discharge port of the rear chamber 7.

Further, the chamber main body 2 is provided with a sealing mechanism 14 adjacent to each of the openings 10a to 13a. Of these sealing mechanisms 14, the sealing mechanism 14 provided adjacent to the partition walls 3 and 4 also serves as a sealing mechanism provided at the discharge port and a sealing mechanism provided at the supply port. All the sealing mechanisms 14 have the same configuration, but the reference numerals of the respective members of the sealing mechanism 14 provided in the chamber main body 2 are omitted.
The sealing mechanism 14 is composed of a resin holder 15 and a pair of sealing rollers 16 and 16 held by the holder 15.
The holder 15 is composed of a pair of holder members 15a and 15b, and these holder members 15a and 15b hold the pair of seal rollers 16 and 16 in between.

The pair of seal rollers 16 are provided with elastic members 16b such as fluorine-based rubber on the outer periphery of a metal rotating shaft 16a, and are held by the holder 15 so as to be crimped to each other.
Further, in the holder 15, the portion corresponding to the crimping portion of the pair of seal rollers 16 has a slit shape having a shape and size substantially equal to the openings 10a to 13a formed in the insulating members 10 to 13. An opening 15c is formed. The opening 15c is a transfer path for the sheet 1 which is an object to be statically eliminated continuously to the openings 10a to 13a.

Further, the holder 15 is formed with an arcuate concave portion that matches the outer periphery of the seal roller 16, but the curvature of the arc on the holder 15 side is made larger than the curvature of the seal roller 16 so that the seal roller 16 has an arc shape. The elastic member 16b is configured to exert a pressing force on the holder 15. Therefore, the outer circumference of the elastic member 16b is in close contact with the holder 15 to prevent outside air from entering the chamber from between the outer circumference of the seal roller 16 and the holder 15.

Further, a rotation drive mechanism such as a motor is connected to the end of the rotation shaft 16a in the length direction to make the seal roller 16 rotatable. Therefore, the sealing mechanism 14 also functions as a transporting means for transporting the sheet 1 in the direction of the arrow x.
When the seal roller 16 rotates, the elastic member 16b slides while pressing the holder, so that the holder 15 is made of a material having good slipperiness and excellent wear resistance, such as Delrin (registered trademark). It is preferable to form with.
As described above, in this embodiment, the sealing mechanism 14 that also serves as a means for transporting the static elimination target prevents outside air from entering the front and rear chambers 6 and 7 and the main chamber 5.
The distance between the sealing mechanisms 14 and 14 adjacent to each other along the transport direction of the sheet 1 is equal to or less than the length of the sheet 1 in the transport direction. Therefore, at least one of the moving sheets 1 is always sandwiched by any of the seal rollers 16 and 16 which also serves as a conveying means, and is conveyed in the arrow x direction.

Next, the configuration inside the main chamber 5 will be described.
In the main chamber 5, a pair of discharge electrodes 17 and 18 constituting the ion irradiation means are provided facing each other from the upstream side in the transport direction of the sheet 1 indicated by the arrow x. Each of the discharge electrodes 17 and 18 is composed of a rod-shaped member extending along the width direction of the sheet 1 or a plurality of electrode members arranged at predetermined intervals in the width direction, and has a length in the width direction of the sheet 1. It is held by electrode holders 19 and 20 made of an electrically insulating material having the above.
Only the portions of the discharge electrodes 17 and 18 facing each other are exposed, and the other portions are covered with the electrode holders 19 and 20. The electrode holders 19 and 20 are electrical insulating materials that cover the discharge electrodes in the present invention.

Then, the facing distance between the electrode holders 19 and 20 coincides with the opening 11a of the partition wall 3 to form a transport path for the sheet 1.
Further, voltages having opposite polarities are applied to the discharge electrodes 17 and 18, respectively, and a discharge is generated between them so that ions are generated. The voltage applied to the discharge electrodes 17 and 18 may be direct current or alternating current as long as they have opposite polarities to each other, but the discharge can be stabilized by using the direct current voltage.

Further, in the main chamber 5, a pair of grounding rollers 21 and 22 are provided in the vicinity of the partition wall 4 on the downstream side. These grounding rollers 21 and 22 are rollers made of metal such as stainless steel having a length equivalent to the width of the sheet 1 which is the object of static elimination, and are rotated by roller holders 23 and 24 made of an electrically insulating material. It is held possible.
The grounding rollers 21 and 22 are usually in contact with each other, but when the sheet 1 is supplied between the facing portions, the grounding rollers 21 and 22 are separated to maintain a facing interval according to the thickness of the sheet 1. It is configured as follows. Specifically, when a light spring force is applied to a pair of rotating shafts (not shown) of both grounding rollers 21 and 22 in a direction in which the rotating shafts approach each other, and when the sheet 1 enters between the grounding rollers 21 and 22 The grounding rollers 21 and 22 are movably supported according to the thickness of the sheet 1.

Further, the outer peripheral portions of the grounding rollers 21 and 22 excluding the contact portions with each other are covered with the roller holders 23 and 24. The roller holders 23 and 24 are electrically insulating materials that cover the grounding roller of the present invention.
Further, between the discharge electrode holders 19 and 20 and the grounding rollers 21 and 22, a guide member 25 made of an electrical insulating material having a transport path 25a for the sheet 1 formed therein is provided. The sheet 1 that has passed through the transport path 25a is guided between the grounding rollers 21 and 22.

In the static elimination device of this embodiment configured as described above, the action of static elimination of the sheet 1 charged to a high potential by digital printing will be described. The sheet 1 is an A4 size multilayer sheet.
The sheet 1 charged and discharged by a printing machine (not shown) is conveyed from the left side of FIG. 1 by the seal rollers 16 and 16 of the seal mechanism 14, and is supplied into the front chamber 6 from the opening 10a of the outer wall 8 to be used for the next seal. It is supplied into the main chamber 5 from the opening 11a of the partition wall 3 via the mechanism 14.

Since the inside of the main chamber 5 is maintained at several hundred [Pa], discharge occurs even if the potential difference between the discharge electrodes 17 and 18 is not so large, and many ions are constantly generated between the discharge electrodes 17 and 18. Has been generated. In particular, since the discharge electrodes 17 and 18 expose only the portion of the sheet 1 facing the transport path, the direction of discharge is concentrated and ions can be generated on the transport path of the sheet 1.
Further, as described above, since the grounding rollers 21 and 22 are also covered with the roller holders 23 and 24 made of an electric insulating material except for the facing portions, the ions generated by the discharge electrodes 17 and 18 are the grounding rollers 21. It can be prevented from being absorbed by 22.
Since ions are generated on the transport path and the ions are not absorbed by the ground rollers 21 and 22, the sheet 1 supplied from the front chamber 6 enters the region where the ions are generated. .. As a result, the surface of the sheet 1 is intensively irradiated with ions, and the surface charge is efficiently neutralized.

The sheet 1 whose surface charge has been discharged in the ion irradiation step is conveyed while being guided by the guide member 25, and when the tip approaches between the ground rollers 21 and 22, the tip surface of the sheet 1 is directed toward the ground rollers 21 and 22 in FIG. Discharge occurs as shown by the arrow shown in.
Further, when the sheet 1 moves and is sandwiched between the ground rollers 21 and 22, a discharge is generated from the widthwise end surface of the sheet 1 toward the ground rollers 21 and 22 as shown in FIG. 3, and the inside of the sheet 1 is generated. The electric charge accumulated in the ground flows to the ground side. When the sheet 1 conveyed while being discharged is passed between the grounding rollers 21 and 22 in this way, it is supplied to the rear chamber 7 from the opening 12a of the partition wall 4 in a state where the static electricity is almost completely eliminated, and further, the sheet 1 is supplied to the rear chamber 7 of the outer wall 9. It is discharged to the outside through the opening 13a and the sealing mechanism 14.

Since the degree of vacuum in the main chamber 5 is maintained at several hundreds [Pa] as described above, electric discharge is easily generated from the charged sheet 1 and the electric charge inside can be eliminated.
Moreover, in this embodiment, on the upstream side of the discharge process including the grounding rollers 21 and 22, the ions generated by the discharge electrodes 17 and 18 are irradiated on the surface of the sheet 1, and the charge amount of the sheet 1 is reduced. Therefore, unlike the case where the sheet 1 having a high charge amount is suddenly sandwiched between the ground rollers 21 and 22 to eliminate static electricity, the discharge current toward the ground rollers 21 and 22 does not become a large current, and the sheet 1 is damaged by the discharge. There is no such thing.
That is, if the static eliminator of this embodiment is used, perfect static elimination is possible without damaging the sheet 1.

Further, in this embodiment, the opening 10a which is the supply port of the front chamber 6, the opening 11a which is the supply port of the main chamber 5, the electrode holders 19 and 20, the guide member 25, and the roller holders 23 and 24 are electrically insulating. It is made of wood.
That is, most of the transport paths of the charged sheet 1 are surrounded by electrical insulation. In other words, the grounded body such as the inner wall of the grounded chamber body 2 is not exposed to the sheet 1.
If the sheet 1 before static elimination approaches the ground body, the sheet 1 may be attracted to the ground body by the charged charge and stick to the ground body. For example, if the tip of the sheet 1 supplied to the front chamber 6 sticks to the metal outer wall 8, the movement of the sheet 1 may stop there or be sent in a crumpled and wrinkled state. .. This also happens in the main chamber 5.
However, in this embodiment, since the sheet 1 and the grounding body are prevented from coming into direct contact with each other, smooth transportation can be realized.

The sheet 1 that has passed between the grounding rollers 21 and 22 and is completely statically eliminated does not have the problem of sticking to the grounding body as described above, but in this embodiment, it has an insulating property that forms an opening. The members 10 to 13 and the sealing mechanism 14 are shared so that the transport path of the sheet 1 is surrounded by the electric insulating material on the downstream side of the grounding rollers 21 and 22 as well as on the upstream side.
However, if the transport means of the sheet 1 can be devised to realize smooth transport, it is not essential to surround the transport path with an electrical insulating material.

Further, since the inside of the main chamber 5 is maintained at a vacuum degree that is very easy to discharge, if the sheet 1 comes into contact with the partition wall 3 or the like which is a grounding body before passing through the ion irradiation step, the sheet 1 is discharged. It will be damaged. Therefore, the insulating member 10 provided on the partition wall 3 also functions to prevent such discharge and to maintain the order of the ion irradiation step and the discharge step.

In this embodiment, the grounding rollers 21 and 22 are used as the discharging means, but the discharging means is not limited to the grounding rollers 21 and 22.
For example, a ground electrode that does not rotate at a distance from the charged sheet 1 may be provided. However, even if the degree of vacuum is such that it is easy to discharge, the distance from the sheet 1 must be as small as possible in order to completely eliminate static electricity. It is difficult to control the dimensions of the grounding electrodes provided at small intervals with respect to the sheet being moved by the transporting means.
Further, since the frictional resistance rapidly increases under vacuum, the sheet 1 cannot be moved when the non-rotating ground electrode is brought into contact with the ground electrode. Therefore, the processing speed may be slowed down.
The grounding rollers 21 and 22 of this embodiment are optimal in that the distance from the grounding electrode can be kept to a minimum while the charged sheet 1 is conveyed, and the distance management is not complicated.

Further, in this embodiment, as shown in FIG. 3, the length of the grounding rollers 21 and 22 is larger than the width of the sheet 1, but the length of the grounding rollers 21 and 22 is larger than the width of the static elimination object. It may be short or long.
However, it is easier to eliminate static electricity if the length of the grounding rollers 21 and 22 is equal to or longer than the width of the static elimination body. This is because if the lengths of the rollers are the same or longer, the distance between the end of the sheet 1 from which the internal charge is discharged and the grounding roller becomes shorter.

Further, in this embodiment, the degree of vacuum in the main chamber 5 is reduced by providing the front chamber 6 and the rear chamber 7 before and after the main chamber 5, which is a vacuum chamber provided with an ion irradiation step and a discharge step for static elimination. I try to maintain it.
A sealing mechanism 14 is provided at the supply port and the discharging port of each chamber, but when the sheet 1 passes through the sealing mechanism 14, outside air inevitably invades.

In particular, when the processing speed of the sheet 1 is increased, the number of sheets 1 passing between the seal rollers 16 and 16 increases per unit time, so that the outside air from between the seal rollers 16 and 16 easily enters. .. However, if the front and rear chambers 6 and 7 in which the degree of vacuum is controlled are provided in front of and behind the main chamber 5, even if outside air enters the front and rear chambers 6 and 7, the influence on the main chamber 5 can be reduced. In other words, by providing the front and rear chambers 6 and 7, the static elimination processing speed can be increased.
Further, the front and rear chambers 6 and 7 are not limited to one before and after the main chamber 5. A plurality of front chambers and rear chambers may be provided so that the degree of vacuum gradually increases toward the main chamber 5.

For example, as shown in FIG. 1, the front and rear chambers 6 and 7 are provided, and the degree of vacuum in the main chamber 5 is kept at about 500 [Pa] and the inside of the front and rear chambers 6 and 7 is kept at about 2000 [Pa] to perform perfect static elimination. The processing amount was 60 sheets per minute. On the other hand, when the sealing mechanism 14 adjacent to the outer walls 8 and 9 was omitted and the insides of the front and rear chambers 6 and 7 were opened to the atmosphere, perfect static elimination was possible with 3 sheets per minute.
By providing the front and rear chambers 6 and 7 in this way, if the degree of vacuum of the main chamber 5 is maintained, continuous processing at high speed can be enabled.
In any case, it is sufficient to set whether or not to provide the front and rear chambers according to the performance of the sealing mechanism, the exhaust capacity of the vacuum pump, the target processing speed, and the like.

This is useful when perfect static elimination is required for the sheet after digital printing.

1 (Static elimination target) Sheet 2 Chamber body 5 Main chamber 6 Front chamber 7 Rear chamber 10a to 13a Openings (supply port, discharge port)
14 Seal mechanism (also serves as a transport means)
15 Holder 16 Seal roller 16a Rotating shaft 16b Elastic member 17, 18 Discharge electrode 10, 20 Electrode holder 21, 22 Grounding roller 23, 24 Roller holder 25 Guide member P1, P2 Vacuum pump

Claims (6)

With a vacuum chamber,
A transport means for transporting an object to be statically eliminated in this vacuum chamber,
Ion irradiation means for irradiating the static elimination target with ions,
A discharge means provided on the downstream side in the transport direction of the static elimination object is provided from the ion irradiation means.
The ion irradiation means is arranged so as to face each other across a transport path of the static elimination object, and is composed of a pair of discharge electrodes to which a voltage of opposite polarity is applied. As well as being covered with insulating material
The discharge means is a static eliminator that is provided in contact with or close to the static elimination target and has a configuration in which the electric charge of the static elimination target flows to the ground side. The main chamber that realizes a vacuum and
At least one sub-chamber arranged in series on each of the upstream side and the downstream side of the main chamber with respect to the transport direction of the static elimination object, and
With a transport means for transporting the static elimination target from the most upstream subchamber to the most downstream subchamber.
Is provided,
In the above main chamber
An ion irradiation means for irradiating the static elimination target conveyed in the main chamber with ions,
A discharge means provided on the downstream side in the transport direction of the static elimination object is provided from the ion irradiation means.
The discharge means and the static elimination target are brought into contact with or close to each other so that the electric charge of the static elimination target flows to the ground side .
In each of the above subchambers
As the vacuum realization means is connected,
A supply port and a discharge port for the above static elimination target are provided.
A static elimination device provided with a seal mechanism that enables the movement of the static elimination target while preventing the intrusion of outside air into these supply ports and discharge ports . The static eliminator according to claim 1 or 2, wherein the discharge means comprises a ground electrode that is in contact with or is close to the static eliminator in the transport path of the static eliminator. The ground electrode constituting the discharge means is composed of a pair of ground rollers that sandwich the static elimination object.
The static elimination device according to claim 3, wherein an electric charge is allowed to flow from the static elimination object passing between the pair of grounding rollers to the grounding side. The static elimination device according to claim 4, wherein the pair of grounding rollers has a length equal to or longer than the width of the static elimination object. The above pair of grounding rollers
The static elimination device according to claim 4, wherein the outer peripheral portion excluding the portion in contact with the transport path of the static elimination target is covered with an electrical insulating material.

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