JP5752476B2 - Static eliminator, static elimination electrode - Google Patents

Description

  The present invention relates to a static eliminator and a static elimination electrode for a container used when a container filled with food, beverage, medicine, or the like is sterilized with an electron beam.

In the filling step of filling a container with a filling such as food, beverage or pharmaceutical, the container is sterilized prior to filling the container with the filling.
In order to sterilize containers, chemicals such as peracetic acid and hydrogen peroxide and ultraviolet irradiation are often used. Yes.

  When a resin container is sterilized by irradiation with an electron beam, there are cases in which electric charges remain inside the resin forming the container. In addition, electric charges stay in the internal space of the container. As a result, the container is charged, and problems such as attracting surrounding dust due to static electricity occur.

  Therefore, a technique has been proposed in which a rod-shaped metal ground electrode is inserted into a container during electron beam irradiation, and electrons and ions are allowed to flow out of the container (for example, see Patent Document 1).

JP2011-26000A

However, it is always desired to solve the problem that the container is charged by electron beam irradiation more reliably and at a lower cost.
Here, a portion near the mouth of the container is complicated in shape, such as a screw groove for screwing the cap, is thick, and the container is held by a holding member called a gripper or the like. Since it is a part, it is difficult to sterilize by electron beam irradiation.
From this point, in the technique described in Patent Document 1, since the rod-shaped electrode is inserted into the container, it is further difficult to sterilize the vicinity of the mouth of the container.
The present invention has been made based on such a technical problem. A neutralization device and a neutralization electrode that can more reliably eliminate charging of a container due to electron beam irradiation, particularly in the vicinity of the mouth of the container. The purpose is to provide.

In view of this, the present inventors considered providing a reflector near the mouth of the container that reflects the irradiated electron beam and irradiates it from the mouth of the container toward the inside.
However, even in that case, since the electrode is inserted in the mouth portion of the container, the problem that it is difficult to sterilize the vicinity of the mouth portion of the container cannot be completely solved.

The static eliminator of the present invention made there is a container holder for holding a container, a rod-like electrode made of a conductive material that is inserted and disposed inside the container, and disposed near the mouth of the container. A reflecting member that reflects the electron beam emitted from the part and irradiates the inside of the container from the mouth part, and the electrode has a cross-sectional area that is at least the part facing the part where the inner diameter of the container is narrower than the other part. It is characterized by having a small cross-sectional area portion of.
In this way, the electrode inserted and arranged inside the container is configured such that at least the part facing the part where the inner diameter of the container is narrow has a small cross-sectional area part having a smaller cross-sectional area than the other part. In the vicinity of the mouth, the electron beam is not easily blocked by the electrode.

  Such an electrode can also be provided integrally with the reflecting member.

  The small cross-sectional area portion may have any configuration, but may be formed, for example, having a rod-shaped small diameter portion whose outer diameter is thinner than other portions. The small cross-sectional area portion can also be formed by having a cylindrical portion formed of a mesh shape or punching metal in which a large number of holes are formed. Of course, a combination of these may be used.

  It is also preferred that the electrode has a variable insertion dimension into the container. Thereby, it becomes possible to deal with containers of various sizes (heights).

  Further, the static eliminator of the present invention includes a container holder for holding a container, a rod-shaped electrode that is inserted and disposed inside the container, and is disposed in the vicinity of the mouth of the container. And a reflecting member that reflects the electron beam irradiated from the mouth and irradiates the inside of the container from the mouth, and the electrode is formed in a cylindrical shape by punching metal having a mesh shape or a large number of holes formed therein. The actual sectional area can be made smaller than the projected sectional area in the direction orthogonal to the axis of the electrode.

Furthermore, the present invention is a rod-like material made of a conductive material, which is inserted and arranged inside the container in order to remove the electric charge remaining in the resin material forming the container sterilized by irradiation with the electron beam. A portion of the container facing the portion with a narrow inner diameter is a small cross-sectional area portion having a smaller cross-sectional area than the other portions, and it can be a neutralizing electrode.
Such a static elimination electrode can also be applied to an existing static elimination device.

  According to the present invention, in this way, the electrode inserted and arranged inside the container has a small cross-sectional area part having a smaller cross-sectional area than other parts at least in a part facing the part where the inner diameter of the container is narrow. By doing so, the electron beam is less likely to be blocked by the electrode in the vicinity of the mouth of the container. As a result, charging of the container due to electron beam irradiation can be more reliably eliminated, particularly near the mouth of the container.

It is a layout figure which shows the outline | summary of the drink filling equipment in this Embodiment. It is a figure which shows schematic structure of the sterilizer in this embodiment. (A) is a figure which shows the example provided with the reflecting plate and the electrode, (b) is a figure which shows the other example of a reflecting plate. It is a figure which shows the some example of a rod-shaped electrode. (A) is a figure which shows the other example of a shape of a reflecting plate, (b) is a figure which shows the example of the electrode which can change length. It is a figure which shows the temperature-electrical resistance characteristic of PET resin which forms a container.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
FIG. 1 is a diagram showing an outline of a beverage filling facility in the present embodiment.
As shown in FIG. 1, in a beverage filling facility, a sterilization process (sterilization device) 10 sterilizes a container made of supplied PET resin by electron beam irradiation, and the filling device 30 fills the container with liquid. The container is filled with the beverage by sequentially performing a filling process and a capping process in which a cap is attached to the container filled with the liquid in the capper 40. A container is conveyed by the star wheel 50 or the conveyance conveyor 60 between the apparatuses which are mutually back and front.
In the example of FIG. 1, two sterilization apparatuses 10 are provided and the container is sterilized from one side and the other side, but the present invention is not limited to this.

The sterilizer 10 used in the sterilization process sterilizes the container by irradiating the container with an electron beam while conveying the container.
As shown in FIG. 2, the sterilizer 10 is inserted into the outer periphery of the disc-shaped rotating body 11 into the gripper (container holder) 12 that holds the supplied container 100 and the container 100 that is held by the gripper 12. A plurality of sets of rod-shaped electrodes 13 are arranged at intervals in the circumferential direction.
Further, the sterilization apparatus 10 is provided with an electron beam irradiation apparatus (electron beam sterilization unit) 20 that irradiates the container 100 held by the gripper 12 with an electron beam on the outer peripheral side of the rotating body 11.

The electron beam irradiation apparatus 20 includes an electron beam generation source 21, a horn 22, and a controller (not shown).
A so-called electron gun can be used as the electron beam generation source 21. The electron beam generation source 21 generates a beam-shaped electron beam and irradiates the container 100 with it. At this time, the electron beam irradiation apparatus 20 is provided with a scanning magnet (not shown). Each of the scanning magnets changes the magnetic field generated according to the applied current, and changes the magnetic field generated by the control of the controller, thereby changing the electron beam generated by the electron beam generation source 21 to a predetermined level. Scan in the direction. Here, it is desirable to scan the electron beam in the height direction of the container 100.
The horn 22 has a cylindrical shape whose cross-sectional dimension increases as the distance from the electron beam generation source 21 increases. The horn 22 is provided so as to surround an electron beam irradiation region when the electron beam is scanned by a scanning magnet.

  The gripper 12 holds empty containers 100 that are delivered one by one from a container conveying means such as a star wheel 50 that rotates at the same speed as the rotating body 11 by sandwiching the neck portion 100c thereof.

The electrode 13 is inserted into the container 100 held by the gripper 12 by a cylinder mechanism or the like (not shown).
The electrode 13 is made of a conductive material made of, for example, stainless steel, tungsten, or the like, and has a rod shape. The length of the electrode 13 is located from the mouth 100a to the vicinity of the bottom 100b of the container 100 when inserted into the container 100. Is set.

Here, the configuration of the electrode 13 will be described.
As shown in FIG. 3, a reflecting plate (reflecting member) that reflects an electron beam irradiated from the electron beam irradiation device in the vicinity of the mouth portion 100 a of the container 100 and irradiates the inside from the mouth portion 100 a of the container 100. 80 is provided.
The electrode 13 is provided integrally with the reflecting plate 80.

  The electrode 13 is formed with a small cross-sectional area 90 that reduces the cross-sectional area in the range of the neck 100c from the mouth 100a of the container 100 to the front of the shoulder 100d whose outer diameter gradually increases. Yes.

  For example, as shown in FIG. 3A, the small cross-sectional area 90 can be formed by a small-diameter portion 91 having a part of the electrode 13 whose outer diameter is smaller than that of the other part. The small diameter portion 91 can guide the electron beam reflected by the reflecting plate 80 to the inside of the container 100 without obstructing.

Other than this, as shown in FIG. 4 (a), a small cross-sectional area portion 90, around the small diameter portion 91, a cylindrical portion 92 made of a material having a large number of openings, such as a metal mesh or punch Ngumetaru Can also be provided. The cylindrical portion 92 can reinforce the small-diameter portion 91 while preventing the transmission of the electron beam.

  In addition, as shown in FIG. 4B, the small cross-sectional area 90 may be provided with a plurality of shafts (small diameter portions) 93 having substantially the same diameter as the small diameter portion 91 around the small diameter portion 91. . This also makes it possible to reinforce the small diameter portion 91 while preventing the transmission of the electron beam.

  Further, as shown in FIG. 4 (c), the configuration shown in FIG. 4 (a) excluding the small-diameter portion 91 at the center, that is, a plurality of arcs arranged at intervals. The small cross-sectional area 90 can also be formed by the shaft 93.

Further, as shown in FIG. 4 (d), the entire electrode 13 can be formed by a cylindrical portion 95 made of a material having a large number of openings, such as a metal mesh or punch Ngumetaru. In this way, the actual cross-sectional area is made smaller than the projected cross-sectional area in the direction orthogonal to the axis of the electrode 13 not only in the range from the mouth part 100a to the neck part 100c of the container 100 but also in the entire length thereof.
Also by this, the function as the electrode 13 can be sufficiently exhibited while the sterilization of the 100c is reliably performed while preventing the passage of the electron beam in the range from the mouth part 100a to the neck part 100c of the container 100. In addition, the electrode 13 can be made lighter and simpler than the configurations of FIGS. 3A and 4A to 4C.

  By the way, as shown in FIG.3 (b), the reflecting plate 80 may form the unevenness | corrugation 81 in the reflective surface, for example. Thereby, the electron beam reflected in the reflecting plate 80 can be scattered and irradiated to the mouth part 100a of the container 100, and the vicinity of the mouth part 100a can be sterilized reliably. Here, there is no intention to limit the shape and number of the irregularities 81 at all.

Further, as shown in FIG. 5A, the reflecting plate 80 may be configured to have a plane 82 that is orthogonal to the axial direction of the electrode 13 at a portion where the electrode 13 is attached. Thereby, the electrode 13 can be easily attached to the reflecting plate 80.
Further, the electrode 13 is fixed to the reflecting plate 80 with a bolt or the like that penetrates the reflecting plate 80 and the tip is screwed into the electrode 13, or the base end portion of the electrode 13 passes through the reflecting plate 80. It can be made the structure which makes it project to the other side and screw nut 84 grade | etc., There. Thereby, replacement | exchange of the electrode 13 can be enabled.

Further, as shown in FIG. 5B, the electrode 13 is inserted into a through hole 85 formed in the reflecting plate 80, and is moved from the through hole 85 to one step side of the reflecting plate 80 by a cylinder mechanism (not shown). It can also be set as the structure which can adjust the protrusion amount of.
With such a configuration, the insertion dimension of the electrode 13 into the container 100 can be varied according to the height of the container 100. Thereby, the highly flexible sterilization apparatus 10 which exhibits the static elimination effect with respect to various containers 100 can be comprised.

The electrode 13 as described above can be grounded. In addition, a voltage can be applied to the electrode 13 from a DC power supply.
In such a sterilization apparatus 10, an electron beam is emitted from the electron beam generation source 21 of the electron beam irradiation apparatus 20 until the container 100 held by the gripper 12 is delivered to the star wheel 50 on the subsequent process side. The container 100 is sterilized by irradiating from the outside.
At the same time, a PET film, which is a material for forming the container 100 by irradiating with an electron beam, is inserted into the container 100 by applying a voltage from a ground or a DC power source to a constant voltage. The charge accumulated inside can be removed, and sterilization and static elimination can be performed at that time.

Further, as shown in FIG. 2, an AC power supply (AC voltage application source) 15 can be connected to the electrode 13 to apply an AC voltage.
At this time, the alternating current to be applied is preferably a frequency that provides a sufficient loss action and current conduction action to the container 100 that is a dielectric, and is required to be 100 Hz or more, and more preferably about k MHz to MHz.

In such a sterilization apparatus 10, an electron beam is emitted from the electron beam generation source 21 of the electron beam irradiation apparatus 20 until the container 100 held by the gripper 12 is delivered to the star wheel 50 on the subsequent process side. The container 100 is sterilized by irradiating from the outside.
At the same time, the electrode 13 to which an alternating voltage is applied is inserted into the container 100, so that charges accumulated in the PET film, which is a material forming the container 100, are removed by irradiating the electron beam, and sterilized. And remove the static electricity at that time.

In this way, by applying an electron beam from the electron beam irradiation apparatus 20 while applying an AC voltage to the electrode 13, weakly ionized plasma generated in the internal space of the container 100 due to the influence of dissipated electrons or the like at the time of electron beam irradiation is generated. Thus, an alternating electric field induced by the potential of the electrode 13 can be applied to the PET film that is a material forming the container 100 that is a non-processed body.
Since the PET film forming the container 100 is an insulator and a dielectric, almost no direct current flows, but when an alternating electric field is applied, it induces time-varying charges on the surface of the container 100. Can do. At that time, a dielectric loss phenomenon occurs in which part of the energy of the electric field when an AC electric field is applied to the dielectric is dissipated as heat in the dielectric. The charges taken into the PET film forming the container 100 by electron beam irradiation increase the dielectric loss phenomenon. As a result, the temperature of the dielectric (PET film forming the container 100) in the vicinity of the region where the charge has been taken up further increases locally. Here, as shown in FIG. 6, it is known that the resistance of PET, which is a dielectric, decreases as the temperature increases. When the resistance value R of the PET film forming the container 100 decreases, the discharge time constant τ = CR (C: capacitance, R: resistance) decreases, so that the inside of the PET film forming the container 100 is charged. Charges easily flow out of the PET film.
In such a state, by irradiating an electron beam while applying an AC voltage to the electrode 13 disposed in the internal space of the container 100, the charge charged inside the PET film forming the container 100 is externally (container 100). The electric charge that has flowed out into the internal space is led out of the container 100 through the electrode 13. In this way, internal charging of the PET film forming the container 100 can be suppressed, and static elimination can be achieved.

  Further, since an alternating current flows when a high-frequency electric field is applied to the PET film of the container 100 from the electrode 13, the charge internally charged in the PET film of the container 100 is caused by the electric field generated by the electrode 13 in the PET film of the container 100. It can also be expected to flow out to the outside (external space and internal space of the container 100).

In this way, by applying an alternating voltage with the electrode 13, the charge accumulated in the PET film forming the container 100 can be easily discharged, thereby more efficiently than when the electrode is set to a constant voltage. Static neutralization can be taken.
Furthermore, the neutralization efficiency is further increased by heating the container 100 by application of an AC voltage.

In addition, in the said embodiment, although the structure of each part of the drink filling equipment and the sterilizer 10 was shown, as long as it is in the scope of the gist of the present invention, it may have any structure.
Further, the configurations of the electrode 13 and the reflecting plate 80 are not limited to the configurations described above, and may be any configurations within the scope of the gist of the present invention.
For example, in FIG. 2, the container 100 is in an upright state, and in the example of FIG. 3, the container 100 is in an inverted state.
In addition to this, as long as it does not depart from the gist of the present invention, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate.

10 Sterilization device (static elimination device)
11 Rotating body 12 Gripper (container support)
13 Electrode 15 AC power supply (AC voltage application source)
20 Electron beam irradiation device (Electron beam sterilization unit)
21 Electron beam generation source 22 Horn 30 Filling device 40 Capper 50 Star wheel 60 Conveyor 80 Reflecting plate (reflecting member)
81 Concavity and convexity 82 Flat surface 84 Nut 85 Through hole 90 Small cross-sectional area 91 Small diameter 92 Tubular 93 Shaft (small diameter)
95 cylindrical part 100 container 100a mouth part 100b bottom part 100c neck part 100d shoulder part

Claims (10)

A container holder for holding the container;
A rod-like electrode inserted and arranged inside the container and made of a conductive material;
A reflective member that is disposed in the vicinity of the mouth of the container, reflects the electron beam irradiated from the electron beam sterilization unit, and irradiates the inside of the container from the mouth;
In the electrode, at least a portion including the mouth portion of the container and facing a portion having a small inner diameter is a small cross-sectional area portion having a smaller cross-sectional area than other portions inserted into the container . The static eliminator characterized by this.   The static eliminator according to claim 1, wherein the electrode is provided integrally with the reflecting member.   3. The static eliminator according to claim 1, wherein the small cross-sectional area portion is formed to have a rod-shaped small diameter portion whose outer diameter is thinner than that of the other portion.   4. The static eliminator according to claim 1, wherein unevenness is formed on the reflection surface of the reflection member. 5.   5. The static eliminator according to claim 1, wherein an AC voltage is applied to the electrode while the container is sterilized by the electron beam sterilization unit. The said small cross-sectional area part has a cylindrical part formed with the mesh shape or the punching metal in which many holes were formed, It is formed as described in any one of Claim 1 to 5 characterized by the above-mentioned. The static elimination apparatus of description. The static elimination apparatus according to any one of claims 1 to 6 , wherein the electrode has a variable insertion dimension into the container.   The electrode penetrates the reflective member;
  8. The static eliminator according to claim 7, wherein a protruding amount of the electrode from the reflecting member is adjustable. A container holder for holding the container;
A rod-like electrode inserted and arranged inside the container and made of a conductive material;
A reflective member that is disposed in the vicinity of the mouth of the container, reflects the electron beam irradiated from the electron beam sterilization unit, and irradiates the inside of the container from the mouth;
The electrode as a whole is formed in a cylindrical shape by punching metal having a mesh shape or a large number of holes, and the actual sectional area is smaller than the projected sectional area in the direction perpendicular to the axis of the electrode. A static eliminator characterized by that. In order to remove the electric charge remaining in the resin material forming the container sterilized by irradiation with the electron beam, it is inserted and arranged inside the container,
A rod-shaped portion made of a conductive material, at least including the mouth portion of the container, a portion facing a portion having a small inner diameter is smaller in cross-sectional area than other portions inserted into the container ; The electrode for static elimination characterized by the above-mentioned.