JP2008004397A - Destaticizing method and static eliminator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a destaticizing method and a static eliminator in which even when charge distribution of a charged object of moving sheet-shape is not uniform, the charges can be neutralized surely and destaticized. <P>SOLUTION: The destaticizing method is provided with a first DC destaticizing step in which a positive and a negative DC high voltage is impressed on a first discharge electrode part 3 and a second discharge electrode part 4 and positive air ions are irradiated on the surface 1a and a negative air ions are irradiated on the surface 1b at a first position 2 along the moving direction of the charged object 1, and a second DC destaticizing step in which a negative and a positive DC high voltage is impressed on a third discharge electrode part 6 and a fourth discharge electrode part 7 and negative air ions are irradiated on the surface 1a and positive air ions are irradiated on the surface 1b at a second position 5, as one set of process, and after the process is repeated once or a plurality of times, is provided with a high frequency destaticizing step in which high frequency high voltage is impressed respectively on a fifth and a sixth discharge electrode parts 9, 10 which are opposed interposing the charged object 1, and the positive and negative air ions generated are supplied on the surfaces 1a, 1b of the charged object 1 at a third position 42. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a static elimination method and a static elimination apparatus for neutralizing static electricity of a charged object by irradiating a charged object with positive and negative air ions generated by generating corona discharge in the air.

  Conventionally, as a device for removing static electricity from a sheet-like charged object such as a moving plastic film, a positive or negative voltage generated at the tip of the discharge needle by applying a DC or AC high voltage to the discharge electrode portion having the discharge needle. There has been known a static eliminator that generates positive and negative air ions by corona discharge and neutralizes the charge of a charged object with the air ions.

  In such a static eliminator, the generated positive and negative air ions are guided to an electric field formed around the charged object and are attracted to the charged object to achieve neutralization. At this time, when the overall electric field of the charged object is positive, only negative air ions are attracted. Conversely, when the overall electric field of the charged object is negative, only positive air ions are attracted. Therefore, in a sheet-like charged object, if the charge distribution is non-uniform and local charging areas are mixed, air ions with the necessary polarity are not supplied to each charging area, It was difficult to neutralize the object.

  On the other hand, a static eliminator that forcibly irradiates the surface of a sheet-like charged object with generated positive and negative air ions has been proposed (for example, Patent Document 1 below). In the static eliminator of Patent Document 1, an ion generating electrode that generates positive and negative air ions is disposed opposite one surface (front surface) of a charged object such as a moving film, and the other surface (back surface) of the charged object. The ion-sucking electrode that sucks positive and negative air ions is arranged opposite to the above. For example, a voltage having a polarity opposite to that applied to the ion generating electrode is applied to the ion attracting electrode. This forcibly irradiates the surface of the charged object with the generated positive and negative air ions.

  However, when the charge distribution is uneven in a sheet-like charged object, the charge distribution may be different between the front surface and the back surface of the charged object. At this time, as in the static eliminator of Patent Document 1, even if one surface of the charged object is forcibly irradiated with positive and negative air ions, the charge that the other surface of the charged object had before the charge removal Air ions are attracted only to a state balanced with the distribution, and it is difficult to neutralize the charged object.

In view of this, a static eliminator has been proposed that forcibly irradiates a sheet-like charged object with positive and negative air ions on both sides of the sheet (for example, Patent Document 2 below). In the static eliminator of Patent Document 2, the static eliminator has a plurality of static eliminator units provided at intervals in the sheet moving direction. 2 electrode units. Each of the first and second electrode units includes first and second ion generation electrodes that are needle electrode arrays, and grounded first and second shield electrodes. Voltages having opposite polarities are applied to the first ion generation electrode and the second ion generation electrode, and the generated positive and negative air ions are irradiated to both surfaces of the sheet. At this time, in the static eliminator of Patent Document 2, a low-frequency AC high voltage is applied to each ion generation electrode in order to balance the generation amount of positive and negative air ions (ion balance) in each static elimination unit. .
JP 7-263173 A JP 2005-222925 A

  However, in the static eliminator of Patent Document 2 described above, since an AC high voltage is applied to the ion generation electrode, the degree to which the generated positive and negative air ions recombine before reaching the charged object is large. In addition, since the electric field distribution temporally changes between positive and negative, the moving speed of the air ions to the charged object becomes slow. Therefore, depending on the charged state of the charged object, sufficient air ions may not be supplied and the charge may not be neutralized. For this reason, for example, in the static elimination apparatus of patent document 2, it is necessary to perform adjustments such as arranging a number of static elimination units and switching the magnitude of the voltage to be applied according to the charged state, which is inconvenient. . Furthermore, in the static eliminator of Patent Document 2, when there are variations in the ability to generate air ions between the static eliminator units, positive and negative charges are alternately generated in the moving direction of the charged object on each surface of the charged object, There is an inconvenience that it is difficult to neutralize the charge on the surface reliably.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a static elimination method and a static elimination apparatus that can neutralize charges and eliminate static charges even when the charge distribution of a moving sheet-like charged object is uneven. And

  The static elimination method of the present invention is a static elimination method in which positive and negative air ions generated by positive and negative corona discharges are supplied to a moving sheet-like charged object. And a second DC static elimination step and a high frequency static elimination step.

  In the first DC neutralization step, a first discharge electrode portion provided to face one surface of the charged object at a first position along the moving direction of the charged object, and at the first position, Positive and negative DC high voltages are applied to a second discharge electrode portion provided opposite to the other surface of the charged object, and positive air ions generated at the first discharge electrode portion are charged. Irradiating the one surface of the object and irradiating the other surface of the charged object with negative air ions generated by the second discharge electrode portion.

  In the second DC neutralization step, a third discharge electrode portion provided opposite to the one surface of the charged object at a second position spaced apart from the first position in the moving direction of the charged object by a predetermined distance. And a negative and positive DC high voltage are applied to the fourth discharge electrode portion provided opposite to the other surface of the charged object at the second position, and the third discharge electrode portion The generated negative air ions are irradiated to the one surface of the charged object, and the positive air ions generated by the second discharge electrode portion are irradiated to the other surface of the charged object.

  In the high-frequency static elimination step, the first DC static elimination step and the second DC static elimination step are set as a set of processes, and after the process is performed once or a plurality of times along the moving direction of the charged object, A high frequency high voltage is applied to each of the fifth discharge electrode part and the sixth discharge electrode part provided opposite to each other across the charged object at a third position along the moving direction of the charged object, Positive and negative air ions generated respectively at the fifth and sixth discharge electrode portions are supplied to one and the other surfaces of the charged object.

  According to the static elimination method of the present invention, in the first DC static elimination step, the first discharge electrode portion and the second discharge electrode portion facing each other with the charged object sandwiched at the first position are reversed in polarity (positive and negative). Therefore, the positive air ions generated in the first discharge electrode part are caused by the electric field formed between the first discharge electrode part and the second discharge electrode part to be applied to one surface of the charged object. The negative air ions generated by the second discharge electrode unit are forcibly irradiated to the other surface of the charged object.

  At this time, since a constant electric field is formed between the first discharge electrode part and the second discharge electrode part by the DC high voltage, for example, compared to the case where the electric field distribution changes with time due to the AC high voltage. The moving speed of air ions is fast. Further, in the first and second discharge electrode portions, air ions of each polarity are continuously generated by the DC high voltage, so the degree to which the air ions are reduced by recombination or the like before reaching the charged object is small. . Therefore, the generated positive and negative air ions are efficiently irradiated on each surface of the charged object. In this way, positive and negative air ions are forcibly and efficiently irradiated onto each surface of the charged object, so even if there is a local charged region on each surface, the charge in the charged region is neutralized. And can be neutralized. As a result, the negatively charged region on one surface is neutralized including the locally charged region, and the positively charged region on the other surface is neutralized including the locally charged region.

  Next, in the second DC neutralization step, a DC high voltage of reverse polarity (negative and positive) is applied to the third discharge electrode part and the fourth discharge electrode part facing each other with the charged object sandwiched at the second position. Therefore, negative air ions generated in the third discharge electrode unit are forcibly irradiated on one surface of the charged object by the electric field formed between the third discharge electrode unit and the fourth discharge electrode unit. The positive air ions generated by the fourth discharge electrode part are forcibly irradiated to the other surface of the charged object.

  At this time, as in the first DC static elimination step, positive and negative air ions are forcibly and efficiently irradiated onto each surface of the charged object, and thus there is a local charged region on each surface. However, the charge in the charged region can be neutralized and neutralized. As a result, the positively charged region on one surface is neutralized including the locally charged region, and the negatively charged region on the other surface is neutralized including the locally charged region.

  Then, the first and second DC static elimination steps are set as a set of processes, and the process is performed once or a plurality of times along the moving direction of the charged object, so that the charge density on each surface of the charged object is not uniform. For example, even when positive and negative local charged areas such as electrostatic marks (static marks) are complicatedly mixed, the charge in the charged areas can be neutralized and neutralized. Here, the generation amount of positive and negative air ions in the first to fourth discharge electrode portions varies depending on, for example, adhesion of dirt and the balance of the irradiation amount of positive and negative air ions irradiated to the charged object ( (Ion balance) may be biased. Therefore, the charged object is in a state where charges of one polarity are attached to one surface according to the bias of the ion balance, and charges of opposite polarity are attached to the other surface corresponding to the charges. At this time, the apparent charge density of the charged object (the sum of the charge densities on both sides) is almost zero. In addition, the charge density on each surface is an overall charge caused by an imbalance in ion balance, so it is usually small, unlike local strong charge.

  Therefore, with respect to the charged object in such a state, positive and negative air ions respectively generated at the fifth and sixth discharge electrode portions are supplied to one and the other surfaces of the charged object in the high-frequency static elimination step. . At this time, since a high frequency high voltage is applied, positive and negative air ions are supplied to each surface of the charged object in a mixed state. Further, the high frequency high voltage is alternating current, and positive and negative air ions are alternately generated in the same discharge electrode part, so that the supplied positive and negative air ions are in an ion balanced state. .

  At this time, since the high-frequency voltages applied to the fifth and sixth discharge electrode portions have the same polarity, the generated positive and negative air ions are not forcibly irradiated, but one of the charged objects and It is attracted and supplied by the electric field formed by the charge on the other surface. That is, since each surface of the charged object is charged to one polarity as a whole, when the positive and negative air ions generated in the fifth discharge electrode portion diffuse and reach the vicinity of one surface, Air ions are attracted by the electric field in the vicinity of the surface, and the charge on one surface is neutralized to neutralize the charge. Similarly, when positive and negative air ions generated in the sixth discharge electrode portion diffuse and reach the vicinity of the other surface of the charged object, the air ions are attracted by the electric field in the vicinity of the other surface, and the other surface Is neutralized and neutralized. At this time, the supply of air ions is not forced irradiation, and the ion balance of the supplied air ions is balanced, so that reverse charging hardly occurs. Therefore, by supplying positive and negative ions to both surfaces of the charged object in the high-frequency charge eliminating step, the charges on each surface can be reliably neutralized and discharged while preventing reverse charging.

  As described above, according to the static elimination method of the present invention, even when the charge distribution of the moving sheet-like charged object is non-uniform, the charge can be reliably neutralized and neutralized.

  Further, the static eliminator of the present invention is a static eliminator that neutralizes static electricity by supplying positive and negative air ions generated by positive and negative corona discharges to a moving sheet-like charged object. One or a plurality of DC static elimination units to which positive and negative DC high voltages are applied, and a high frequency high voltage provided on the traveling side in the moving direction of the charged object from the DC static elimination unit. And a high-frequency static elimination unit to be applied.

  The DC neutralizing unit includes a first discharge electrode portion provided to face one surface of the charged object at a first position along the moving direction of the charged object, and the charged object at the first position. A second discharge electrode portion provided opposite to the other surface of the first electrode, and the second discharge electrode portion facing the one surface of the charged object at a second position spaced apart from the first position in the moving direction of the charged object. A third discharge electrode portion provided at the second position, and a fourth discharge electrode portion provided opposite to the other surface of the charged object at the second position.

  Further, the DC static elimination unit is configured to apply positive air ions generated in the first discharge electrode unit by applying positive and negative DC high voltages to the first and second discharge electrode units. Irradiating one surface and irradiating the other surface of the charged object with negative air ions generated by the second discharge electrode unit, and applying negative and positive to the third and fourth discharge electrode units By applying a DC high voltage, negative air ions generated at the third discharge electrode part are irradiated to the one surface of the charged object, and positive air ions generated at the fourth discharge electrode part are irradiated with the negative air ions. Irradiate the other surface of the charged object.

  The high-frequency static elimination unit includes a fifth discharge electrode portion and a sixth discharge electrode portion that are provided to face each other with the charged object interposed therebetween at a third position along the moving direction of the charged object. The high-frequency static elimination unit is configured to apply positive and negative air ions generated in the fifth and sixth discharge electrode portions, respectively, to the charged object by applying a high-frequency high voltage to the fifth and sixth discharge electrode portions. Supply to one and the other side.

  According to the static eliminator of the present invention, in the DC static eliminator unit, the first discharge electrode part and the second discharge electrode part facing each other with the charged object sandwiched between the first position and the opposite polarity (positive and negative) DC high voltage. Since a voltage is applied, positive air ions generated in the first discharge electrode part are forced on one surface of the charged object by the electric field formed between the first discharge electrode part and the second discharge electrode part. The negative air ions generated by the second discharge electrode unit are forcibly irradiated to the other surface of the charged object.

  At this time, as described in the first direct current neutralization step of the neutralization method of the present invention, positive and negative air ions are forcibly and efficiently irradiated onto each surface of the charged object, so that each surface is locally localized. Even when a charged region exists, the charge in the charged region can be neutralized and neutralized. As a result, the positively charged region on one surface is neutralized including the locally charged region, and the negatively charged region on the other surface is neutralized including the locally charged region. As a result, the negatively charged region on one surface is neutralized including the locally charged region, and the positively charged region on the other surface is neutralized including the locally charged region.

  Further, since a DC high voltage of opposite polarity (negative and positive) is applied to the third discharge electrode portion and the fourth discharge electrode portion facing each other with the charged object sandwiched at the second position, the third discharge electrode portion Due to the electric field formed between the fourth discharge electrode part, negative air ions generated in the third discharge electrode part are forcibly irradiated to one surface of the charged object, and are generated in the fourth discharge electrode part. Positive air ions are forcibly irradiated on the other surface of the charged object.

  At this time, as described in the second DC static elimination step of the static elimination method of the present invention, positive and negative air ions are forcibly and efficiently irradiated on each surface of the charged object, so that each surface is locally localized. Even when a charged region exists, the charge in the charged region can be neutralized and neutralized. As a result, the positively charged region on one surface is neutralized including the locally charged region, and the negatively charged region on the other surface is neutralized including the locally charged region.

  Accordingly, even when the charge density of each surface of the charged object is uneven due to one or a plurality of DC static elimination units, for example, when positive and negative local charged regions such as electrostatic marks are mixedly mixed, The charge in the charged region can be neutralized and neutralized. Here, the generation amount of positive and negative air ions in the first to fourth discharge electrode portions varies depending on, for example, adhesion of dirt and the balance of the irradiation amount of positive and negative air ions irradiated to the charged object ( (Ion balance) is biased. Therefore, the charged object is in a state where charges of one polarity are attached to one surface according to the bias of the ion balance, and charges of opposite polarity are attached to the other surface corresponding to the charges. At this time, the apparent charge density of the charged object (the sum of the charge densities on both sides) is almost zero. In addition, the charge density on each surface is an overall charge caused by an imbalance in ion balance, so it is usually small, unlike local strong charge.

  Therefore, positive and negative air ions generated respectively by the fifth and sixth discharge electrode portions are supplied to one and the other surfaces of the charged object by the high-frequency static elimination unit. At this time, as described for the high frequency step of the static elimination method of the present invention, since a high frequency high voltage is applied, positive and negative air ions are supplied to each surface of the charged object in a mixed state. Further, the high frequency high voltage is alternating current, and positive and negative air ions are alternately generated in the same discharge electrode part, so that the supplied positive and negative air ions are in an ion balanced state. .

  At this time, since the high-frequency voltages applied to the fifth and sixth discharge electrode portions have the same polarity, the generated positive and negative air ions are not forcibly irradiated, but one of the charged objects and It is attracted and supplied by the electric field formed by the charge on the other surface. That is, since each surface of the charged object is charged to one polarity as a whole, when the positive and negative air ions generated in the fifth discharge electrode portion diffuse and reach the vicinity of one surface, Air ions are attracted by the creeping electric field in the vicinity of the surface, and the charge on one surface is neutralized to neutralize the charge. Similarly, when the positive and negative air ions generated in the sixth discharge electrode portion diffuse and reach the vicinity of the other surface of the charged object, the air ions are attracted by the creeping electric field in the vicinity of the other surface, and the other The charge on the surface is neutralized and neutralized. At this time, the supply of air ions is not forced irradiation, and the ion balance of the supplied air ions is balanced, so that reverse charging hardly occurs. Therefore, by supplying positive and negative ions to both surfaces of the charged object with the high-frequency neutralizing unit, it is possible to neutralize the charges on each surface and prevent the charge while preventing reverse charging.

  As described above, according to the static eliminator of the present invention, even when the charge distribution of the moving sheet-like charged object is not uniform, the charge can be reliably neutralized and neutralized.

  In the static eliminator of the present invention, the first discharge electrode portion includes one or more first discharge needles, the second discharge electrode portion includes one or more second discharge needles, and the third discharge electrode. The part has one or more third discharge needles, and the fourth discharge electrode part has one or more fourth discharge needles. Further, each of the first discharge needle and the second discharge needle is disposed on a row extending at a predetermined interval from the charged object along the width direction of the charged object. The first discharge needles and the second discharge needles are arranged so as to be alternately arranged with the axis of each discharge needle facing the charged object. Further, the third discharge needle and the fourth discharge needle are respectively arranged on a row extending at a predetermined interval from the charged object along the width direction of the charged object, It is preferable that the third discharge needle and the fourth discharge needle are respectively arranged so as to be alternately arranged with the axial center of each discharge needle facing the charged object.

  According to the static eliminator, the first discharge needle and the second discharge needle alternate with respect to the width direction of the sheet-like charged object (the direction parallel to the sheet surface of the charged object and perpendicular to the moving direction of the charged object). Placed in. For example, a plurality of first discharge needles are arranged on a row extending at a predetermined interval from the charged object along the width direction of the charged object, with the axis thereof facing the one surface of the charged object, It is arranged at equal intervals. In addition, a plurality of second discharge needles are placed on the other row opposite to the row where the first discharge needles are arranged with the charged object interposed therebetween, and the axis of the second discharge needle faces the other surface of the charged object. Are arranged at equal intervals. At this time, each second discharge needle is shifted by a half pitch (half of the interval between each first and second discharge needle) from each first discharge needle in the width direction of the charged object (each second discharge needle is (Disposed between two successive first discharge needles). As a result, when air ions are irradiated onto each surface of the charged object, the air ions spread in the width direction of the charged object and are uniformly distributed and irradiated in the vicinity of the first position.

  Similarly, the third discharge needles and the fourth discharge needles are alternately arranged in the width direction of the sheet-like charged object. Thus, when air ions are irradiated onto each surface of the charged object, the air ions are spread and uniformly distributed in the width direction of the sheet-like charged object in the vicinity of the second position.

  Therefore, since air ions are evenly irradiated on both surfaces of the sheet-like charged object, static elimination is performed more efficiently.

  Further, in the static eliminator of the present invention, the distance between the first position and the second position is determined such that the shortest distance between the first discharge electrode part and the second discharge electrode part and the third discharge electrode. It is preferable to take a larger distance than the shortest distance between the portion and the fourth discharge electrode portion.

  That is, in the DC static elimination unit, an electric field is formed between the first discharge electrode portion and the second discharge electrode portion, between the third discharge electrode portion and the fourth discharge electrode portion, and between the adjacent discharge electrode portions. An electric field is also formed between the first discharge electrode portion and the third discharge electrode portion and between the second discharge electrode portion and the fourth discharge electrode portion. At this time, the distance between the first position and the second position (the distance between adjacent discharge electrode parts) is the shortest distance between the first discharge electrode part and the second discharge electrode part, and the third The electric field formed between the first discharge electrode part and the second discharge electrode part and the third discharge if the distance is larger than the shortest distance between the discharge electrode part and the fourth discharge electrode part. The electric field formed between the electrode part and the fourth discharge electrode part is stronger than the electric field formed between the adjacent discharge electrode parts. Accordingly, air ions attracted to the adjacent discharge electrode portions are reduced, and more air ions move toward the opposing discharge electrode portions and are irradiated onto the sheet-like charged object. Therefore, the charge removal of the sheet-like charged object can be performed more efficiently.

  The shortest distance between the first discharge electrode part and the second discharge electrode part and the shortest distance between the third discharge electrode part and the fourth discharge electrode part are, for example, the tip of the first discharge needle. And the shortest distance between the tip of the second discharge needle and the shortest distance between the tip of the third discharge needle and the tip of the fourth discharge needle.

  Further, in the static eliminator of the present invention, a first electric field shielding wall made of an insulator is provided between the first discharge electrode portion and the third discharge electrode portion, and the second discharge electrode portion and the fourth discharge are provided. It is preferable to provide the 2nd electric field shielding wall which consists of an insulator between electrode parts.

  According to the static eliminator, the first and second electric field shielding walls shield the electric field formed by the first and second discharge electrode portions and the electric field formed by the third and fourth discharge electrode portions, respectively. Therefore, the interference of the electric field between the adjacent discharge electrode portions can be prevented. Therefore, it is not necessary to increase the interval between the adjacent discharge electrode portions in order to reduce the interference of the electric field, and it is possible to reduce the size of the static eliminator by reducing the interval between the adjacent discharge electrode portions.

[First Embodiment]
As shown in FIG. 1, a film (sheet-like charged object) 1 that is a charge removal target of the charge removal device of the present embodiment is predetermined in the direction indicated by the arrow by the rotation of rollers 11 and 12 installed at a plurality of locations. It moves continuously at a speed (for example, 10 to 100 m / min). The film 1 is an electrically insulating sheet such as a plastic film.

  The static eliminator of this embodiment includes one or a plurality (two in this embodiment) of DC neutralization units 8 and 8a to which positive and negative DC high voltages are applied along the moving direction of the film 1, and a high frequency high voltage. A high-frequency static elimination unit 43 to which a voltage is applied.

The first direct current neutralization unit 8 includes first to fourth discharge electrode portions 3, 4, 6, and 7 that generate corona discharge to generate air ions. The first discharge electrode portion 3 is provided at a first position 2 along the moving direction of the film 1 so as to be opposed to the one surface 1a of the film 1 with a predetermined distance. Further, the second discharge electrode portion 4 is provided at the first position 2 so as to be opposed to the other surface 1b of the film 1 at a predetermined distance. At this time, the first discharge electrode part 3 the distance between the second discharge electrode part 4 and the distance D _1. The third discharge electrode portion 6, from a first position 2 in a second position 5 spaced a predetermined distance L ₁ in the moving direction of the film 1, at a predetermined distance from one surface 1a of the film 1 It is provided facing. Further, the fourth discharge electrode portion 7 is provided at a second position 5 so as to be opposed to the other surface 1b of the film 1 at a predetermined distance. At this time, the third discharge electrode part 6 the distance between the fourth discharge electrode portions 7 and the distance D _2.

  The first and fourth discharge electrode portions 3 and 7 indicated by white triangles in FIG. 1 are connected to a positive DC high-voltage power supply 13 via connection lines 14 and 15, respectively. In these first and fourth discharge electrode portions 3 and 7, a positive DC high voltage (for example, +7 kV) output from the positive DC high-voltage power supply 13 is applied to generate a positive corona discharge, and positive air ions Is generated. Further, the second and third discharge electrode portions 4 and 6 indicated by black triangles in FIG. 1 are connected to a negative DC high-voltage power supply 18 via connection lines 19 and 20, respectively. In these second and third discharge electrode portions 4 and 6, a negative DC high voltage (for example, −7 kV) output from the negative DC high-voltage power supply 18 is applied to generate a negative corona discharge, and negative air Ions are generated. The configuration of the positive and negative DC high-voltage power supplies 13 and 18 may be a known configuration.

Similar to the first DC neutralization unit 8, the second DC neutralization unit 8a includes first to fourth discharge electrode portions 3a, 4a, 6a, and 7a that generate corona discharge to generate air ions. Yes. The first discharge electrode section 3a, first in first position 2a, opposite spaced one predetermined distance from the surface 1a of the film 1 second position 5 away from a predetermined distance L ₂ in the traveling direction of the film 1 Is provided. Further, the second discharge electrode portion 4a is provided to be opposed to the other surface 1b of the film 1 with a predetermined distance at the first position 2a. At this time, the distance between the first discharge electrode part 3a and the second discharge electrode part 4a and the distance D _3. The third discharge electrode portion 6a is in a second position 5a spaced a predetermined distance L ₃ in the moving direction of the film 1 from the first position 2a, at a predetermined distance from one surface 1a of the film 1 It is provided facing. The fourth discharge electrode portion 7a is provided to face the second surface 5b of the second position 5a with a predetermined distance from the other surface 1b. At this time, the distance between the third discharge electrode portions 6a and the fourth discharge electrode portions 7a and the distance D _4.

  The first and fourth discharge electrode portions 3 a and 7 a indicated by white triangles in FIG. 1 are connected to a positive DC high-voltage power supply 13 via connection lines 16 and 17, respectively. In these first and fourth discharge electrode portions 3 a and 7 a, as in the first and fourth discharge electrode portions 3 and 7, a positive DC high voltage output from the positive DC high-voltage power supply 13 is applied. Corona discharge occurs and positive air ions are generated. In addition, the second and third discharge electrode portions 4a and 6a indicated by black triangles in FIG. 1 are connected to a negative DC high-voltage power supply 18 via connection lines 21 and 22, respectively. In these second and third discharge electrode portions 4a and 6a, as in the second and third discharge electrode portions 4 and 6, the negative DC high voltage output from the negative DC high-voltage power supply 18 is applied and negatively applied. Corona discharge occurs and negative air ions are generated.

The high-frequency static elimination unit 43 includes fifth and sixth discharge electrode portions 9 and 10 that generate corona discharge to generate air ions. The fifth discharge electrode portion 9, in the third position 42 spaced a second predetermined distance L ₄ in the moving direction from the position 5a film 1, opposite from the one surface 1a of the film 1 at a predetermined distance Is provided. Further, the sixth discharge electrode portion 10 is provided to be opposed to the other surface 1b of the film 1 with a predetermined distance at the third position 42.

  The fifth and sixth discharge electrode portions 9 and 10 indicated by white circles in FIG. 1 are connected to a high-frequency and high-voltage power source 23 via connection lines 24 and 25, respectively. In the fifth and sixth discharge electrode portions 9 and 10, a high voltage (for example, ± 2 kV) output from the high-frequency and high-voltage power supply 23 is applied, and positive and negative corona discharges are alternately performed. And positive and negative air ions are generated alternately. The configuration of the high frequency high voltage power source 23 may be a known configuration.

The distance L _1, L ₃ between the two discharge electrodes of each DC static eliminating units 8,8a, for example the same spacing. Further, the interval L ₂ between the first DC static elimination unit 8 and the second DC static elimination unit 8a is, for example, an interval of L ₁ and L ₃ or more. In addition, the interval L ₄ between the second DC static elimination unit 8a and the high-frequency static elimination unit 43 is, for example, an interval of L _{1 to} L ₃ or more. In addition, the distances D _{1 to} D ₄ between the discharge electrode portions are all set to the same distance, for example.

The first to fourth discharge electrode portions 3, 4, 6, 7, 3 a, 4 a, 6 a, 7 a are, for example, a plurality of discharge needles each made of a conductor, as described in a second embodiment described later, A discharge needle support member made of a rod-shaped conductor on which the discharge needle is arranged is provided. At this time, the discharge needles of the first and third discharge electrode portions 3, 6, 3a, 6a are the same as the discharge needles of the second, fourth discharge electrode portions 4, 7, 4a, 7a, respectively. They are placed facing each other with the film 1 in between. The distances D _{1 to} D ₄ between the opposing discharge electrode portions are the shortest distances between the tip of the discharge needle of each discharge electrode portion and the tip of the discharge needle of the opposing discharge electrode portion. Similarly, the fifth and sixth discharge electrode portions 9 and 10 are each formed of a plurality of discharge needles made of a conductor and a rod-like conductor on which the discharge needles are arranged, as will be described in a second embodiment described later. And a plurality of ground electrode portions.

  Next, the operation (static elimination operation) of the static eliminator of this embodiment will be described.

  First, in the first DC neutralization unit 8, as the first DC neutralization step S <b> 1, the positive DC high voltage output from the positive DC high voltage power supply 13 is applied to the first discharge electrode unit 3 via the connection line 14. On the other hand, a negative DC high voltage output from the negative DC high-voltage power supply 18 is applied to the second discharge electrode unit 4 via the connection line 19. A constant electric field is formed between the first discharge electrode portion 3 and the second discharge electrode portion 4 by applying the positive and negative DC high voltages. As a result, positive corona discharge is generated in the first discharge electrode portion 3 and positive air ions are continuously generated, and negative corona discharge is generated in the second discharge electrode portion 4 and negative air ions are generated. Are generated continuously. At this time, positive air ions generated in the first discharge electrode unit 3 are attracted to the second discharge electrode unit 4 and are forcibly irradiated onto the surface 1 a of the film 1 in the vicinity of the first position 2. The Negative air ions generated by the second discharge electrode unit 4 are attracted to the first discharge electrode unit 3 and are forcibly irradiated onto the surface 1 b of the film 1 in the vicinity of the first position 2. .

  Further, as the second DC static elimination step S2, a negative DC high voltage output from the negative DC high voltage power source 18 is applied to the third discharge electrode unit 6 via the connection line 20, while a positive DC high voltage is applied. A positive DC high voltage output from the power supply 13 is applied to the fourth discharge electrode portion 7 via the connection line 15. A constant electric field is formed between the third discharge electrode portion 6 and the fourth discharge electrode portion 7 by the application of the positive and negative DC high voltages. As a result, negative corona discharge is generated in the third discharge electrode portion 6 and negative air ions are continuously generated, and positive corona discharge is generated in the fourth discharge electrode portion 7 and positive air ions are generated. Are generated continuously. At this time, negative air ions generated in the third discharge electrode portion 6 are attracted to the fourth discharge electrode portion 7 and are forcibly irradiated onto the surface 1 a of the film 1 in the vicinity of the second position 5. The Further, positive air ions generated in the fourth discharge electrode portion 7 are attracted to the third discharge electrode portion 6 and are forcibly irradiated onto the surface 1 b of the film 1 in the vicinity of the second position 5. .

  Next, in the second DC neutralization unit 8a, as the first DC neutralization step S3, the positive DC high voltage output from the positive DC high-voltage power supply 13 in the neutralization unit 8a is connected via the connection line 16 to the first DC neutralization step S3. A negative DC high voltage that is applied to the first discharge electrode unit 3 a and output from the negative DC high-voltage power supply 18 is applied to the second discharge electrode unit 4 a via the connection line 21. By the application of the positive and negative DC high voltages, a positive corona discharge is generated in the first discharge electrode portion 3a as in the first DC neutralization step S1 in the first DC static elimination unit 8, and positive air Ions are continuously generated, and negative corona discharge is generated in the second discharge electrode portion 4a to continuously generate negative air ions. Positive air ions generated by the first discharge electrode portion 3a are attracted to the second discharge electrode portion 4a and are forcibly irradiated onto the surface 1a of the film 1 in the vicinity of the first position 2a. Moreover, the negative air ion produced | generated by the 2nd discharge electrode part 4a is attracted | sucked by the 1st discharge electrode part 3a, and is forcibly irradiated to the surface 1b of the film 1 in the vicinity of the 1st position 2a. .

  In the second DC neutralization step S4, a negative DC high voltage output from the negative DC high voltage power source 18 is applied to the third discharge electrode portion 6a via the connection line 22, and the positive DC high voltage power source 13 is applied. Is applied to the fourth discharge electrode portion 7 a through the connection line 17. By the application of the positive and negative DC high voltages, negative corona discharge is generated in the third discharge electrode portion 6a as in the second DC neutralization step S2 in the first DC neutralization unit 8, and negative air is generated. While ions are continuously generated, positive corona discharge is generated in the fourth discharge electrode portion 7a, and positive air ions are continuously generated. Negative air ions generated by the third discharge electrode portion 6a are attracted to the fourth discharge electrode portion 7a and are forcibly irradiated onto the surface 1a of the film 1 in the vicinity of the second position 5a. Moreover, the positive air ion produced | generated by the 4th discharge electrode part 7a is attracted | sucked by the 3rd discharge electrode part 6a, and is forcibly irradiated to the surface 1b of the film 1 in the vicinity of the 2nd position 5a. .

  In the first to fourth discharge electrode portions 3, 4, 6, 7, 3a, 4a, 6a, and 7a, positive or negative air ions are continuously generated. The degree to which the air ions decrease due to recombination or the like before reaching the film 1 is small. In addition, since a constant electric field is formed, the moving speed of air ions does not become slow due to temporal changes in the electric field distribution. Therefore, the positive and negative air ions generated in the DC neutralization steps S1 to S4 are efficiently irradiated on the film 1, respectively.

  Further, in the high frequency static elimination unit 43, as a high frequency static elimination step S <b> 5, the high frequency high voltage output from the high frequency high voltage power source 23 is applied to the fifth discharge electrode portion 9 via the connection line 24 and also via the connection line 25. Applied to the sixth discharge electrode portion 10. Since the high-frequency voltage is an AC voltage, positive and negative high voltages are alternately applied to the fifth discharge electrode portions 9 and 10, respectively. By the application of the high frequency high voltage, high frequency corona discharge is generated in the fifth discharge electrode portions 9 and 10, respectively, and positive and negative air ions are generated alternately. At this time, positive and negative air ions are alternately generated by the same fifth and sixth discharge electrode portions 9 and 10, respectively, so that dirt and the like adhering to the fifth and sixth discharge electrode portions 9 and 10 can be prevented. Regardless, the balance (ion balance) between the production amounts of positive air ions and negative air ions generated by the fifth and sixth discharge electrode portions 9 and 10 is obtained.

  Positive and negative air ions generated by the fifth discharge electrode unit 9 are supplied to the surface 1 a of the film 1 in the vicinity of the third position 42. Further, positive and negative air ions generated by the sixth discharge electrode unit 10 are supplied to the surface 1 b of the film 1 in the vicinity of the third position 42. At this time, since the high-frequency voltage applied to the fifth and sixth discharge electrode portions 9 and 10 has the same polarity, positive and negative air ions generated by the fifth and sixth discharge electrode portions 9 and 10 are Rather than forcibly irradiating the surfaces 1a and 1b, the surfaces 1a and 1b are attracted to the surfaces 1a and 1b according to the electric field formed by the charges on the surfaces 1a and 1b of the film 1.

  Next, the charge removal of the film 1 will be described according to the above steps S1 to S5. In addition, the film 1 before static elimination has local double-sided bipolar charging (for example, a local charged region of positive polarity and negative polarity is mixed on both sides 1a and 1b, such as an electrostatic mark (static mark). In a charged state).

  First, in the first DC neutralization step S1 in the first DC neutralization unit 8, when the predetermined portion of the moving film 1 comes to the first position 2, the surface 1a around the predetermined portion has a charge distribution on the surface. Instead, positive air ions generated by the first discharge electrode unit 3 are forcibly irradiated. At the same time, the negative air ions generated by the second discharge electrode portion 4 are forcibly irradiated to the surface 1b around the predetermined portion regardless of the charge distribution on the surface.

  The positive air ions irradiated on the surface 1a are attracted to the negatively charged region on the surface 1a to neutralize the negative charge. At this time, since positive air ions are forcibly irradiated, the charges in the local charged region can be neutralized. When there is a negative charged region on the surface 1b, the irradiated positive air ions are attracted to the negative charged region and adhere to the surface 1a. Moreover, the negative air ion irradiated to the surface 1b is attracted to the positive charge area | region on the surface 1b, and neutralizes a positive charge. At this time, since negative air ions are forcibly irradiated, the charges in the locally charged region can be neutralized. When there is a positively charged region on the surface 1a, the irradiated negative air ions are attracted to the positively charged region and adhere to the surface 1b.

  As a result, the negatively charged region on the surface 1a is neutralized including the locally charged region. Further, the positively charged region on the surface 1b is neutralized including the locally charged region.

  Next, when the predetermined portion of the moving film 1 comes to the second position 5 in the second direct current neutralization step S2 in the first direct current neutralization unit 8, the charge distribution on the surface is distributed on the surface 1a around the predetermined portion. Regardless, negative air ions generated by the third discharge electrode unit 6 are forcibly irradiated. At the same time, the surface 1b around the predetermined portion is forcibly irradiated with positive air ions generated by the fourth discharge electrode portion 7 regardless of the charge distribution on the surface.

  Negative air ions irradiated on the surface 1a are attracted to the positively charged region on the surface 1a to neutralize the positive charge. At this time, since negative air ions are forcibly irradiated, the charges in the locally charged region can be neutralized. When there is a positively charged region on the surface 1b, the irradiated negative air ions are attracted to the negatively charged region and adhere to the surface 1a. Further, the positive air ions irradiated on the surface 1b are attracted to the negatively charged region on the surface 1b to neutralize the negative charge. At this time, since positive air ions are forcibly irradiated, the charges in the local charged region can be neutralized. When there is a negatively charged region on the surface 1a, the irradiated positive air ions are attracted to the negatively charged region and adhere to the surface 1b.

  As a result, the positively charged region on the surface 1a is neutralized including the locally charged region. Further, the negatively charged region on the surface 1b is neutralized including the locally charged region.

  Next, when a predetermined portion of the moving film 1 comes to the first position 2a in the first DC neutralization step S3 in the second DC neutralization unit 8a, the first DC neutralization in the first DC neutralization unit 8 is performed. Similar to step S1, the surface 1a around the predetermined portion is forcibly irradiated with positive air ions generated by the first discharge electrode portion 3a, and the surface 1b is negatively generated by the second discharge electrode portion 4a. Air ions are forcibly irradiated.

  The positive air ions irradiated on the surface 1a are attracted to the negatively charged region on the surface 1a to neutralize the negative charge. At this time, since negative air ions are forcibly irradiated, the charges in the locally charged region can be neutralized. When there is a negative charged region on the surface 1b, the irradiated positive air ions are attracted to the negative charged region and adhere to the surface 1a. Moreover, the negative air ion irradiated to the surface 1b is attracted to the positive charge area | region on the surface 1b, and neutralizes a positive charge. At this time, since negative air ions are forcibly irradiated, the charges in the locally charged region can be neutralized. When there is a positively charged region on the surface 1a, the irradiated negative air ions are attracted to the positively charged region and adhere to the surface 1b.

  As a result, the negatively charged area on the surface 1a around the predetermined portion of the film 1 is neutralized including the local charged area, and the local charged area disappears and the whole is positively charged. . In addition, the positively charged region on the surface 1b is neutralized including the locally charged region, and the locally charged region disappears and is negatively charged as a whole.

  Next, when the predetermined portion of the moving film 1 comes to the second position 5a in the second DC neutralization step S4 in the second DC neutralization unit 8a, the second DC neutralization in the first DC neutralization unit 8 is performed. Similarly to step S2, the negative air ions generated by the third discharge electrode portion 6a are forcibly irradiated to the surface 1a around the predetermined portion, and the positive surface generated by the fourth discharge electrode portion 7a is applied to the surface 1b. Air ions are forcibly irradiated.

  Negative air ions irradiated on the surface 1a are attracted to the positively charged region on the surface 1a to neutralize the positive charge. Further, the positive air ions irradiated on the surface 1b are attracted to the negatively charged region on the surface 1b to neutralize the negative charge. Thereby, both the surface 1a and the surface 1b are neutralized around the predetermined part of the film 1.

  At this time, when the irradiation amount of positive and negative air ions irradiated to the film 1 from the first to fourth discharge electrode portions is balanced (ion balance), all charges on the film 1 are neutralized. It becomes the state. However, it is generally considered that the generation amount of positive and negative air ions in the first to fourth discharge electrode portions varies due to, for example, adhesion of dirt to the first to fourth discharge electrode portions. For this reason, the balance of the irradiation amount of the positive and negative air ions with which the film 1 is irradiated from the first to fourth discharge electrode portions is biased. Therefore, as a result of the first and second DC neutralization steps S1 to S4, the film 1 has one polarity of charge attached to one surface according to the bias of the ion balance, and the other surface corresponding to the charge. Then, it will be in the state to which the charge of reverse polarity adhered. For example, a negative charge is attached to the surface 1a, and a positive charge is attached to a portion on the surface 1b corresponding to the negative charge attached portion on the surface 1a.

  Therefore, by the above first and second DC neutralization steps S1 to S4, the entire surface 1a is charged to one polarity (for example, negative) and the entire surface 1b is reversely polarized (for example, positive) around the predetermined portion of the film 1. It will be in a charged state. In the following description, the case where the surface 1a is negatively charged and the surface 1b is positively charged will be described as an example. At this time, the apparent charge density around the predetermined portion of the film 1 (the sum of the charge densities of both surfaces 1a and 1b) is almost zero. In addition, the charge density on each surface is an overall charge caused by an imbalance in ion balance, so it is usually small, unlike local strong charge.

  Next, when the film 1 moves and the predetermined portion comes close to the third position 42 in the high-frequency static elimination step S5, the positive and negative generated by the fifth discharge electrode unit 9 are formed on the surface 1a around the predetermined portion. Air ions are supplied, and positive and negative air ions generated by the sixth discharge electrode unit 10 are supplied to the surface 1b. Note that positive and negative air ions are supplied in a mixed state.

  At this time, since the surface 1a is negatively charged as a whole, when the positive air ions generated in the fifth discharge electrode portion 9 diffuse and reach the vicinity of the surface 1a of the film 1, the vicinity of the surface 1a These positive air ions are attracted by the electric field. On the other hand, since the surface 1a is negatively charged as a whole, negative air ions generated by the fifth discharge electrode portion 9 are not attracted. Thereby, positive air ions attracted to the surface 1a are attracted and the negative charges on the surface 1a are neutralized.

  Further, since the surface 1b is positively charged as a whole, when the negative air ions generated in the sixth discharge electrode portion 10 diffuse and reach the vicinity of the surface 1b of the film 1, the surface 1b The negative air ions are attracted by the electric field. On the other hand, since the surface 1b is positively charged as a whole, positive air ions generated by the sixth discharge electrode portion 10 are not attracted. Thereby, negative air ions attracted to the surface 1b are attracted and the positive charges on the surface 1b are neutralized.

  In the high-frequency static elimination step S5, since the supply of positive and negative air ions is not forced irradiation, reverse charging to the surfaces 1a and 1b hardly occurs. For example, when the negative charge on the surface 1a side is neutralized and neutralized, negative air ions are easily attracted to the positive charge attached to the surface 1b side corresponding to the negative charge. Become. Similarly, for example, when the positive charge on the surface 1b side is neutralized and neutralized, positive air ions are attracted to the negative charge adhering to the surface 1a side corresponding to the positive charge. It becomes easy. In this way, by supplying positive and negative ions from both surfaces, the charge removal on each surface proceeds without a significant bias in the apparent charge density. Therefore, the high-frequency neutralization step S5 can neutralize the negative charge on the surface 1a and the positive charge on the surface 1b with certainty while preventing reverse charging.

  By the above process, the charge of the film 1 is reliably neutralized and neutralized.

  According to the present embodiment, the surface 1a and the surface 1b of the film 1 are forcibly irradiated with air ions with opposite polarities by the DC neutralization step using positive and negative DC high voltages. It is possible to neutralize the charge in the charged region and neutralize the charge. Furthermore, since the air ions having the same polarity are supplied to the both surfaces 1a and 1b of the film 1 by the high-frequency neutralization step by the high-frequency and high-voltage after the direct current neutralization step, each surface 1a, The charge of 1b can be reliably neutralized and neutralized.

  In the present embodiment, a set of the first and second DC neutralization steps S1 and S2 in the first DC neutralization unit 8 and the first and second DC neutralization steps S3 and S4 in the second DC neutralization unit 8a. Each set corresponds to one set of processes. This embodiment corresponds to a case where a high-frequency static elimination step is performed after this process is performed twice along the moving direction of the film 1. This step may be performed once or three times or more. For example, the irradiation amount of the positive and negative air ions irradiated in the first and second DC neutralization steps S1 and S2 in the first DC neutralization unit 8 is larger than the charge amount in the locally charged region of the film 1. In the case where the number is sufficiently large, it is possible to neutralize local both-side bipolar charging even in a single step.

In the present embodiment, the first to fourth discharge electrode portions 3, 3a, 4, 4a, 6, 6a, 7, and 7a are each provided with a discharge needle and a discharge needle support member. The sixth discharge electrode portions 9 and 10 are each provided with a discharge needle, a discharge needle support member, and a ground electrode portion. However, the present invention is not limited thereto, and the configuration thereof can be changed.
[Second Embodiment]
In the second embodiment shown in FIGS. 2 to 4, only the first DC static elimination unit 8 in the first embodiment is provided along the moving direction of the film 1. In the following description, the same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description thereof is omitted.

  As shown in FIGS. 2 and 3, the first to fourth discharge electrode portions 3, 4, 6, 7 of the static eliminator according to the present embodiment are respectively a plurality of first to fourth discharge needles 27, 29, 31. , 33 and first to fourth discharge needle support members 26, 28, 30, 32 on which the first to fourth discharge needles 27, 29, 31, 33 are disposed. In addition, the 1st-4th discharge needles 27, 29, 31, and 33 are the same number, respectively.

The first to fourth discharge needle support members 26, 28, 30, and 32 are each made of a rod-shaped conductor, and the axis of the first to fourth discharge needle support members 26, 28, 30, and 32 is parallel to the width direction of the film 1. In a direction perpendicular to the moving direction of The first discharge needle support member 26 and the second discharge needle support member 28 are provided to face each other at a predetermined interval across the film 1 at the first position 2. The fourth discharge needle support member 32 is provided at a second position 5 so as to face the film 1 with a predetermined interval therebetween. The first and fourth discharge needle support members 26 and 32 are connected to the positive DC high-voltage power supply 13 via connection lines 14 and 15, respectively. The second and third discharge needle support members 28 and 30 are connected to the negative DC high-voltage power supply 18 via connection lines 19 and 20, respectively. Further, in the longitudinal direction of the first to fourth discharge needle support members 26, 28, 30, 32, a plurality of first to fourth discharge needles 27, 29, 31, 33 are respectively arranged at a predetermined interval P ₁ . It is arranged in one row at intervals.

  The plurality of first to fourth discharge needles 27, 29, 31, and 33 are each made of a conductor, and the base ends thereof are fixed to the first to fourth discharge needle support members 26, 28, 30, and 32. . Each of the first to fourth discharge needles 27, 29, 31, 33 is arranged so that the axis is directed in a direction perpendicular to the surfaces 1 a, 1 b of the film 1 and the tips thereof are opposed to the film 1. .

At this time, as shown in FIG. 3, the first discharge needles 27 and the second discharge needles 29 are arranged so as to be alternately arranged in the width direction of the film 1 (the III-III line direction in FIG. 2). . Specifically, a first discharge needles 27 and the second discharge needles 29, are staggered by a half pitch (P _1/2). Similarly, the third discharge needles 31 and the fourth discharge needles 33 are arranged so as to be alternately arranged in the width direction of the film 1.

  In addition, the fifth and sixth discharge electrode portions 9 and 10 have a plurality of fifth and sixth discharge needles 35 and 38 and fifth and sixth discharge needles 35 and 38, respectively. Discharge needle support members 34 and 37 and a plurality of (two in the present embodiment) fifth and sixth ground electrode portions 36 and 39 are provided. The number of fifth and sixth discharge needles 35 and 38 provided in the fifth and sixth discharge electrode portions 9 and 10 is the same.

  The fifth and sixth discharge needle support members 34 and 37 are each made of a rod-shaped conductor, and the axial centers thereof are parallel to the surfaces 1 a and 1 b of the film 1 and perpendicular to the moving direction of the film 1. Has been placed. The fifth discharge needle support member 34 and the sixth discharge needle support member 37 are provided to face each other at a predetermined interval across the film 1 at the third position 42. The fifth and sixth discharge needle support members 34 and 37 are connected to the high-frequency and high-voltage power supply 23 via connection lines 24 and 25, respectively. In the longitudinal direction of the fifth and sixth discharge needle support members 34 and 37, a plurality of fifth and sixth discharge needles 35 and 38 are arranged in a line at equal intervals, respectively.

  The plurality of fifth and sixth discharge needles 35 and 38 are each made of a conductor, and the base ends thereof are fixed to the fifth and sixth discharge needle support members 34 and 37. Each of the fifth and sixth discharge needles 35 and 38 is arranged with its axis oriented in a direction perpendicular to the surfaces 1a and 1b of the film 1. At this time, each of the fifth discharge needles 35 and each of the sixth discharge needles 38 are provided such that their tips are opposed to each other with a predetermined interval across the film 1.

  The two fifth ground electrode portions 36 are each made of a rod-shaped conductor, and are disposed opposite to both sides of the row of the fifth discharge needles 35. These fifth ground electrode portions 36 are common ground electrode portions for all the fifth discharge needles 35. Similarly, the two sixth ground electrode portions 39 are each made of a rod-shaped conductor, and are disposed opposite to both sides of the row of the sixth discharge needles 38. These sixth ground electrode portions 39 are common ground electrode portions for all the discharge needles 38. The fifth ground electrode portion 36 and the sixth ground electrode portion 39 are provided so as to face each other with a predetermined interval across the film 1. Each of the fifth and sixth ground electrode portions 36 and 39 is grounded via a connection line (not shown). The configuration other than that described above is the same as that of the first embodiment.

  In the first to sixth discharge electrode portions 3, 4, 6, 7, 9, and 10, the first to sixth discharge needles 27, 29, 31, 33, 35, and 38 are respectively connected to the first to sixth discharges. It is assumed that the needle support members 26, 28, 30, 32, 34, and 37 are directly coupled. It may be a thing.

  Next, the operation (static elimination operation) of the static eliminator of this embodiment will be described. First, in the DC static elimination unit 8, in the first DC static elimination step S1, the first discharge needle 27 in the first discharge electrode part 3 and the second in the second discharge electrode part 4 are applied by applying positive and negative DC high voltages. When an electric field is formed between the discharge needle 29 and the first and second discharge needles 27 and 29, the electric field is concentrated. As a result, positive corona discharge is generated at the tip of each first discharge needle 27 to generate positive air ions, and negative corona discharge is generated at the tip of each second discharge needle 29 to generate negative air ions. Generated.

  Positive air ions generated at the tips of the first discharge needles 27 move toward the surface 1 a of the film 1 in accordance with the electric field formed between the second discharge needles 29. Further, the negative air ions generated at the tip of each second discharge needle 29 move toward the surface 1 b of the film 1 according to the electric field formed between each first discharge needle 27.

  At this time, as shown in FIG. 4 (b), the first discharge needles 27 and the second discharge needles 29 are shifted by a half pitch, so that positive air ions are transferred to the first discharge needles. It moves toward the surface 1a according to the electric field formed between the two second discharge needles 29 in the vicinity. Similarly, negative air ions move toward the surface 1b according to the electric field formed between each second discharge needle 29 and the two adjacent first discharge needles 27. Therefore, at the first position 2 along the moving direction of the film 1, air ions spread in the width direction of the film 1 and are uniformly distributed and irradiated. Thereby, air ions are uniformly irradiated in the width direction of the first position 2, and the charges on the surfaces 1a and 1b of the film 1 are efficiently neutralized. As shown in FIG. 4A, when the first discharge needles 27 and the second discharge needles 29 are arranged to face each other, in the width direction of the first position 2 of the film 1, Air ions concentrate and irradiate the portions facing the first and second discharge needles 27 and 29.

  Further, the second DC neutralization step S2 is performed in the same manner as the first DC neutralization step S1 described above.

  In the present embodiment, since only the first DC static elimination unit 8 is provided, the DC static elimination steps S3 and S4 are not performed as in the first embodiment, and the process proceeds to the high frequency static elimination step S5 as it is. In the high-frequency static elimination step S5, when a high frequency high voltage is applied in the operation of the static elimination unit 43, an electric field is formed between the fifth discharge needle 35 and the fifth ground electrode portion 36 in the fifth discharge electrode portion 9, The electric field concentrates on the tip of the fifth discharge needle 35. As a result, positive and negative corona discharges are generated at the tips of the fifth discharge needles 35 to generate positive and negative air ions. Similarly, an electric field is formed between the sixth discharge needle 38 and the sixth ground electrode part 39 in the sixth discharge electrode portion 10, and the electric field concentrates on the tip of each sixth discharge needle 38. As a result, positive and negative corona discharges are generated at the tips of the sixth discharge needles 38 to generate positive and negative air ions.

  The operations other than those described above are the same as in the first embodiment.

  According to the present embodiment, as in the first embodiment, it is possible to neutralize the charge in the locally charged regions of the surfaces 1a and 1b of the film 1 by the direct current neutralization step. Furthermore, the high-frequency neutralization step performed after the direct current neutralization step can neutralize the charges on the surfaces 1a and 1b while preventing reverse charging of the film 1 and neutralize the charges.

  At the same time, according to the present embodiment, the first discharge needles 27 and the third discharge needles 29 are alternately shifted by a half pitch, so that when air ions are applied to the surfaces 1a and 1b, In the vicinity of the first position 2, air ions spread in the width direction of the film 1 and are uniformly distributed and irradiated. In addition, since the third discharge needles 31 and the fourth discharge needles 33 are alternately shifted by a half pitch, when the air ions are applied to the surfaces 1a and 1b, in the vicinity of the second position 5. Air ions spread in the width direction of the film 1 and are uniformly distributed and irradiated. Thereby, since air ion is uniformly irradiated to the surface 1a, 1b of the film 1, static elimination is performed more efficiently.

In this embodiment, one DC static elimination unit is provided. However, as in the first embodiment, two or more three or more DC static elimination units may be provided.
[Third Embodiment]
The third embodiment shown in FIG. 5 is different from the first embodiment only in the arrangement of the first to fourth discharge electrode portions 3, 4, 6, 7, 3a, 4a, 6a, 7a. In the following description, the same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description thereof is omitted.

In the static eliminator in the present embodiment, the first to fourth discharge electrode portions 3, 4, 6, 7 are the first positions 2 of the first and second discharge electrode portions 3, 4 along the moving direction of the film 1. The distance L ₁ between the third discharge electrode portion 6 and the second discharge electrode portion 7 and the second position 5 is such that the tip of the first discharge needle 27 of the first discharge electrode portion 3 and the second discharge electrode portion 4 second. the shortest distance D ₁ of the the tip of the discharge needle 29, than the shortest distance D ₂ between the tip of the tip of the third discharge needle 31 of the third discharge electrode portions 6 and the fourth discharge needle 33 of the fourth discharge electrode portions 7 It is arranged to be larger. The first discharge electrode portions 3a, 4a, 6a and 7a are also arranged in the same manner as the first discharge electrode portions 3, 4, 6 and 7. The configuration other than that described above is the same as that of the first embodiment.

  And in the static elimination operation of the static elimination apparatus of this embodiment, the positive air ion produced | generated by the 1st discharge electrode part 3 is attracted | sucked by the 2nd discharge electrode part 4, and in the vicinity of the 1st position 2, it is a film. The first surface 1a is forcibly irradiated. Negative air ions generated by the second discharge electrode unit 4 are attracted to the first discharge electrode unit 3 and are forcibly irradiated onto the surface 1 b of the film 1 in the vicinity of the first position 2. .

  At this time, as shown in FIGS. 5 (a) and 5 (b), between the tip of the first discharge needle 27 and the tip of the second discharge needle 29, the tip of the third discharge needle 31 and the tip of the fourth discharge needle 33. Between the tip of the first discharge needle 27 and the tip of the third discharge needle 31, and between the tip of the second discharge needle 29 and the tip of the fourth discharge needle 33. Is formed.

  Thus, for example, for one discharge needle A of the first discharge needles 27, the electric field between the tip of the discharge needle A and the tip of the discharge needle B facing the discharge needle A of the second discharge needle 29. Is formed. Further, an electric field is formed between the tip of the discharge needle A and the tip of the discharge needle C adjacent to the discharge needle A in the third discharge needle 31. The positive air ions generated at the tip of the discharge needle A move toward the discharge needle B according to the electric field formed between the tip of the discharge needle A and the tip of the discharge needle B, and at the same time, the discharge needle. It moves toward the discharge needle C according to the electric field formed between the tip of A and the tip of the discharge needle C.

At this time, as shown in FIG. 5A, the distance between the tip of the discharge needle A and the tip of the discharge needle B (= distance D ₁ ) is the distance between the tip of the discharge needle A and the tip of the discharge needle C ( = Lapse L ₁ ), the electric field formed between the tip of the discharge needle A and the tip of the discharge needle B is between the tip of the discharge needle A and the tip of the discharge needle C. It becomes weaker than the formed electric field. Therefore, the number of air ions moving from the tip of the discharge needle A toward the tip of the discharge needle B and irradiating the film 1 is less than the air ions moving from the tip of the discharge needle A toward the tip of the discharge needle C. Become. On the other hand, as shown in FIG. 5B, when the distance D ₁ is smaller than the distance L ₁ , the direction of the electric field formed between the tip of the discharge needle A and the tip of the discharge needle B Is stronger than the electric field formed between the tip of the discharge needle A and the tip of the discharge needle C. Therefore, since more air ions move from the discharge needle A toward the discharge needle B and are irradiated onto the film 1, the air ions can be efficiently irradiated onto the film 1.

  The first to fourth discharge electrode portions 3a, 4a, 6a, and 7a are the same as the first to fourth discharge electrode portions 3, 4, 6, and 7, respectively. The operations other than those described above are the same as in the first embodiment.

  According to the present embodiment, as in the first embodiment, it is possible to neutralize the charge in the locally charged regions of the surfaces 1a and 1b of the film 1 by the direct current neutralization step. Further, the high-frequency neutralization step performed after the direct current neutralization step can neutralize the charges on the surfaces 1a and 1b reliably while preventing reverse charging of the film 1, thereby eliminating the charge.

  At the same time, according to the present embodiment, since the interval between the discharge electrode portions is larger than the distance between the discharge needles, air ions attracted to the adjacent discharge electrode portions are reduced, and more Air ions are irradiated to the film 1. Therefore, the charge removal of the film 1 can be performed more efficiently.

In the present embodiment, in the static eliminator of the first embodiment, the arrangement of the first discharge electrode portions 3, 4, 6, 7, 3a, 4a, 6a, and 7a is different. In the static eliminator of the second embodiment, the arrangement of the first discharge electrode portions 3, 4, 6, 7 may be different. At this time, the distance between the opposing discharge electrode portions is, for example, the shortest distance between the tip of the discharge needle of one discharge electrode portion and the tips of the two discharge needles in the vicinity of the discharge needle in the other discharge electrode portion. To do.
[Fourth Embodiment]
The fourth embodiment shown in FIG. 6 is obtained by providing an electric field shielding wall in the first embodiment. In the following description, the same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description thereof is omitted.

  As shown in FIG. 6, in the static elimination apparatus in this embodiment, the 1st which consists of an insulator so that the surface 1a side of the film 1 may each cover the 1st, 3rd discharge electrode part 3, 6, 3a, 6a. An electric field shielding wall 40 is provided. The first electric field shielding wall 40 is opened on the surface 1a side of the first and third discharge electrode portions 3, 6, 3a, 6a, and the film 1 of the first, third discharge electrode portions 3, 6, 3a, 6a is opened. It covers both sides in the direction orthogonal to the moving direction and the back side of the first and third discharge electrode portions 3, 6, 3a, 6a. Moreover, the 2nd electric field shielding wall 41 which consists of an insulator is provided in the surface 1b side of the film 1 so that the 2nd, 4th discharge electrode part 4, 7, 4a, 7a may be covered, respectively. The second electric field shielding wall 41 is open on the surface 1b side of the second and fourth discharge electrode portions 4, 7, 4a, 7a, and the second electric field shield wall 41 of the film 1 of the second, fourth discharge electrode portions 4, 7, 4a, 7a. It covers both sides in the direction orthogonal to the moving direction and the back side of the second and fourth discharge electrode portions 4, 7, 4a, 7a. The configuration other than that described above is the same as that of the first embodiment.

  Thereby, the electric field formed between the first discharge electrode part 3 and the second discharge electrode part 4 by the electric field shielding walls 40 and 41, and between the third discharge electrode part 6 and the fourth discharge electrode part 7. The interference with the electric field formed by can be reduced. Similarly, interference between the electric field formed between the third discharge electrode portion 6 and the fourth discharge electrode portion 7 and the electric field formed between the first discharge electrode portion 3a and the second discharge electrode portion 4a. Can be reduced. Similarly, interference between the electric field formed between the first discharge electrode portion 3a and the second discharge electrode portion 4a and the electric field formed between the third discharge electrode portion 6a and the fourth discharge electrode portion 7a. Can be prevented. Therefore, since the space | interval of the adjacent discharge electrode part can be made small, a static elimination apparatus can be reduced in size.

  According to this embodiment, it is possible to neutralize and neutralize charges in the locally charged regions of the surfaces 1a and 1b of the film 1 by the DC neutralization step. Furthermore, the high-frequency neutralization step performed after the direct current neutralization step can neutralize the charges on the surfaces 1a and 1b while preventing reverse charging of the film 1 and neutralize the charges.

  At the same time, according to the present embodiment, the electric field formed by each discharge electrode portion is shielded by the electric field shielding walls 40 and 41, so that the electric field interference between the adjacent discharge electrode portions can be reduced. . Therefore, since it is not necessary to increase the interval between the adjacent discharge electrode portions in order to reduce the interference of the electric field, the interval between the adjacent discharge electrode portions can be reduced to reduce the size of the static eliminator.

  In this embodiment, the electric field shielding wall is provided in the static eliminator of the first embodiment. However, as another embodiment, the electric field shielding wall may be provided in the static eliminator of the second embodiment. .

The schematic block diagram of the static elimination apparatus in 1st Embodiment of this invention. The block diagram which shows the static elimination apparatus in 2nd Embodiment of this invention. FIG. 3 is an end view taken along line III-III in FIG. 2. Explanatory drawing of the static elimination action in the static elimination apparatus of FIG. Explanatory drawing of the static elimination action of the static elimination apparatus in 3rd Embodiment of this invention. The schematic block diagram of the static elimination apparatus in 4th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Film, 1a ... One side of film 1, 1b ... The other side of film 1, 2, 2a ... 1st position, 3, 3a ... 1st discharge electrode part, 4, 4a ... 2nd discharge electrode part 5, 5a ... 2nd position, 6, 6a ... 3rd discharge electrode part, 7, 7a ... 4th discharge electrode part, 8, 8a ... DC static elimination unit, 9 ... 5th discharge electrode part, 10 ... 6th Discharge electrode part, 27, 29, 31, 33, 35, 38 ... discharge needle, 40, 41 ... electric field shielding wall, 42 ... third position, 43 ... high frequency static elimination unit.

Claims (5)

In a static elimination method for eliminating static electricity by supplying positive and negative air ions generated by positive and negative corona discharge to a moving sheet-like charged object,
A first discharge electrode provided opposite to one surface of the charged object at a first position along the moving direction of the charged object; and opposed to the other surface of the charged object at the first position. Then, positive and negative DC high voltages are applied to the second discharge electrode portion provided to irradiate the one surface of the charged object with positive air ions generated by the first discharge electrode portion. And a first DC static elimination step of irradiating the other surface of the charged object with negative air ions generated by the second discharge electrode part;
A third discharge electrode provided opposite to the one surface of the charged object at a second position spaced apart from the first position in the moving direction of the charged object by the second position; Negative and positive DC high voltages are applied to a fourth discharge electrode portion provided opposite to the other surface of the charged object, and negative air ions generated at the third discharge electrode portion are Irradiating the one surface of the charged object with a second direct current charge eliminating step for irradiating the other surface of the charged object with positive air ions generated by the fourth discharge electrode part;
The first DC neutralization step and the second DC neutralization step are set as a set of processes, and after the process is performed once or a plurality of times along the moving direction of the charged object, the charged object is moved. A high frequency high voltage is applied to each of the fifth discharge electrode portion and the sixth discharge electrode portion provided opposite to each other with the charged object interposed therebetween at a third position along the direction, and A high-frequency static elimination step for supplying positive and negative air ions respectively generated by the six discharge electrode portions to one and the other surfaces of the charged object. In a static eliminator that removes static electricity by supplying positive and negative air ions generated by positive and negative corona discharges to a moving sheet-like charged object,
One or a plurality of DC neutralizing units to which positive and negative DC high voltages are applied are provided along the moving direction of the charged object, and provided on the traveling side of the charged object in the moving direction from the DC neutralizing unit. And a high-frequency static elimination unit to which a high-frequency high voltage is applied,
The DC neutralizing unit includes a first discharge electrode portion provided to face one surface of the charged object at a first position along the moving direction of the charged object, and the charged object at the first position. A second discharge electrode portion provided opposite to the other surface of the first electrode, and the second discharge electrode portion facing the one surface of the charged object at a second position spaced apart from the first position in the moving direction of the charged object. A third discharge electrode portion provided in the second position, and a fourth discharge electrode portion provided opposite to the other surface of the charged object at the second position,
By irradiating the one surface of the charged object with positive air ions generated by the first discharge electrode unit by applying positive and negative DC high voltages to the first and second discharge electrode units, By irradiating the other surface of the charged object with negative air ions generated by the second discharge electrode part, and by applying negative and positive DC high voltage to the third and fourth discharge electrode parts, Irradiating negative air ions generated at the third discharge electrode part to the one surface of the charged object, and positive air ions generated at the fourth discharge electrode part to the other surface of the charged object To irradiate
The high-frequency static elimination unit includes a fifth discharge electrode portion and a sixth discharge electrode portion provided to face each other with the charged object interposed therebetween at a third position along the moving direction of the charged object,
By applying a high frequency high voltage to the fifth and sixth discharge electrode portions, positive and negative air ions generated in the fifth and sixth discharge electrode portions, respectively, are applied to one and other surfaces of the charged object. A static eliminator characterized by being supplied. 3. The static eliminator according to claim 2, wherein the first discharge electrode portion includes one or more first discharge needles, the second discharge electrode portion includes one or more second discharge needles, and the third discharge needle. The discharge electrode portion has one or more third discharge needles, the fourth discharge electrode portion has one or more fourth discharge needles,
Each of the first discharge needle and the second discharge needle is disposed on a row extending at a predetermined interval from the charged object along the width direction of the charged object. The first discharge needle and the second discharge needle are arranged so as to be alternately arranged with the axis of each discharge needle facing the charged object.
The third discharge needle and the fourth discharge needle are respectively disposed on a row extending at a predetermined interval from the charged object along the width direction of the charged object. The static eliminator characterized in that the third discharge needles and the fourth discharge needles are arranged alternately with the axial centers of the respective discharge needles facing the charged object.   4. The static eliminator according to claim 2, wherein an interval between the first position and the second position is set to a shortest distance between a tip of the first discharge needle and a tip of the second discharge needle, and The static eliminator characterized in that it is larger than the shortest distance between the tip of the third discharge needle and the tip of the fourth discharge needle.   5. The static eliminator according to claim 2, wherein a first electric field shielding wall made of an insulator is provided between the first discharge electrode portion and the third discharge electrode portion, and the second discharge electrode portion. And a fourth electric field shielding wall made of an insulator between the first discharge electrode portion and the fourth discharge electrode portion.

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