JP2021028228A - Electron beam irradiation device and electron beam irradiation method - Google Patents

Abstract

To provide an electron beam irradiation technique for radiating electron beam to the whole outer surface of a cylindrical container by one electron beam irradiation device and with one irradiation while using electron beam of low to medium energy.SOLUTION: An electron beam irradiation device comprises: transport means which holds a bottomed cylindrical container so that a side face thereof faces an irradiation direction of electron beam, and transports the same; and electron beam irradiation means comprising an electron beam irradiation part which accelerates electron beam toward the container and radiates the same. Transport means includes a plurality of rollers which move in a transport direction while rotating, are inclined with respect to the transport direction and arranged at constant intervals, and is so configured as to transport the container located between adjacent two rollers while rotating the same. The device comprises a variable angle mechanism, over the whole circumference of a side face of which a flange part is provided and which can change an inclination angle with respect to a vertical direction of a rotation axis of the roller, at one end of the roller.SELECTED DRAWING: Figure 1B

Description

The present invention relates to an electron beam irradiation device and an electron beam irradiation method, and more particularly to an electron beam irradiation device and an electron beam irradiation method including a rotary transfer mechanism.

For packaging containers such as pharmaceuticals, cosmetics and beverages, it is obligatory to sterilize and sterilize the containers before filling them, and then fill and seal the contents in a sterile room.

As specific sterilization methods, high-pressure steam sterilization using high-temperature and high-pressure steam, EOG sterilization using ethylene oxide gas (EOG), irradiation sterilization using radiation such as γ-rays and electron beams, and the like are known.

Of these, high-pressure steam sterilization uses high-temperature and high-pressure steam, so a high-pressure chamber is required, and the object must withstand high-temperature and high-pressure. Therefore, high-pressure steam sterilization cannot be said to be a sterilization method suitable for plastic containers widely used in recent years.

Further, although EOG sterilization can be sterilized at a low temperature, the time required for sterilization and removal of residual gas is relatively long. In addition, since EOG has carcinogenicity, stricter regulations are required.

For this reason, in recent years, radiation sterilization has been widely adopted, and among them, electron beam sterilization, which does not require the use of radioactive substances, is increasingly being adopted. In such electron beam irradiation sterilization, not only the outer surface of the container can be sterilized, but also the inner surface of the container can be sterilized depending on the material and thickness of the container.

In conventional electron beam irradiation sterilization, the entire surface of the container is sterilized by irradiating the container with a high-energy electron beam with high penetrating power from the outside of the container to sterilize the electron beam and allow the thickness of the container to pass through. (See Patent Documents 1 and 2). Since this method packs the container, it can be sterilized and then transported to the user.

However, when the above method is adopted, there is a risk that the outer surface of the container is contaminated between the time when the package is opened and the time when the contents are filled. Therefore, there is a demand for an in-line type electron beam irradiation technique capable of continuously performing sterilization and filling of contents in a filling line of contents. In addition, in order to prevent recontamination when opening the package after sterilizing it in a state of being packed with a high-energy electron beam, double packaging and technology for sterilizing the outer surface of the container before filling the contents. Is also required.

In order to perform such in-line electron beam irradiation, the device is required to be small, but the above-mentioned conventional high-energy electron beam irradiation device has a large device scale and shields generated X-rays. In order to do so, a large shield facility such as a concrete shield is required. Therefore, the high-energy electron beam irradiator cannot be said to be suitable for in-line electron beam irradiation.

On the other hand, low-energy and medium-energy electron beam irradiators are small in scale, and the shield equipment may be a small self-shield using a lead shield (see Patent Document 3), so that they can be used for in-line electron beam irradiation. It can be said that it is a suitable facility.

However, the container to be sterilized generally has a bottomed tubular shape. Therefore, if low-energy and medium-energy electron beams with low penetrating power are irradiated from one direction of the container, for example, from the side surface side, the electron beam cannot be irradiated to the back surface side or the bottom surface, and the irradiation is performed. It causes unevenness.

Therefore, as a method for eliminating the occurrence of such irradiation unevenness, for example, a first electron beam accelerator that irradiates an electron beam from the bottom surface side while supporting and transporting the side surface of the tubular container and a tubular container are used. A second electron beam accelerator that irradiates electron beams from the side surface side while supporting and rotating from the bottom surface side is arranged, and irradiation by the first electron beam accelerator and irradiation by the second electron beam accelerator are continuously performed. A continuous sterilization apparatus has been proposed (see Patent Document 4).

However, although such a continuous sterilizer can irradiate an electron beam over the entire circumference of the bottom surface and the side surface of the container, it requires two transport means for the container and two electron beam accelerators, respectively. Larger size is inevitable. In addition, since it is necessary to irradiate the electron beam in two steps, it cannot be said to be an efficient process, and there is a problem in improving productivity.

Japanese Unexamined Patent Publication No. 11-13017 JP-A-2018-95257 Jikkenhei 5-62900 International release WO2013 / 062006

In view of the above-mentioned problems in the conventional electron beam irradiation sterilization, the present invention can be performed with one electron beam irradiation device and one irradiation while using a low energy or medium energy electron beam. An object of the present invention is to provide an electron beam irradiation technique capable of irradiating the entire outer surface of a bottom tubular container with an electron beam.

The present inventor has diligently studied the solution to the above problem, found that the above problem can be solved by the invention described below, and has completed the present invention.

The invention according to claim 1
An electron beam irradiator that irradiates an electron beam toward a bottomed tubular container.
A transport means having a transport path for holding the container so that its side surface faces the irradiation direction of the electron beam and transporting the container from the upstream side to the downstream side.
An electron beam irradiating means including an electron beam irradiating unit for accelerating and irradiating electrons toward the container to be conveyed along the transport path is provided.
In the transport means, a plurality of rollers that move in the transport direction while rotating are inclined with respect to the transport direction and arranged at regular intervals, and the container is arranged between two adjacent rollers. It is configured to be transported while rotating,
The roller is provided with a flange portion that protrudes radially from the side surface at one end in the longitudinal direction over the entire circumference of the side surface, and the inclination angle of the rotation axis of the roller with respect to the vertical direction is changed. It is equipped with a variable angle mechanism that can be used.
The electron beam irradiation device is configured to adjust the irradiation angle of the electron beam with respect to the container by adjusting the inclination angle.

The invention according to claim 2
The electron beam irradiation device according to claim 1, wherein the protruding width of the collar portion is smaller than the distance between the side surface of the container and the rotation center of the container.

The invention according to claim 3
The electron beam irradiation device according to claim 1 or 2, wherein the surface of the collar portion in contact with the container is mirror-finished.

The invention according to claim 4
The electron beam irradiation device according to any one of claims 1 to 3, wherein the surface of the collar portion in contact with the container is formed of metal.

The invention according to claim 5
An electron beam irradiation method for irradiating an electron beam toward a bottomed tubular container using the electron beam irradiation device according to any one of claims 1 to 4.
A transfer step in which the container placed by adjusting the inclination angle of the roller is held so that the side surface faces the irradiation direction of the electron beam at a predetermined angle, and the container is conveyed from the upstream side to the downstream side. ,
It is provided with an electron beam irradiation step of accelerating and irradiating electrons toward the side surface of the container to be transported along the transport path.
In the transfer step, the electron beam irradiation method is characterized in that the container arranged between two adjacent rollers is transferred while rotating.

According to the present invention, an electron beam capable of irradiating the entire outer surface of a tubular container with a single irradiation with one electron beam irradiator while using a low-energy or medium-energy electron beam. Irradiation technology can be provided.

It is a schematic diagram which shows the basic aspect of the electron beam irradiation apparatus which concerns on one Embodiment of this invention. It is the AA arrow view of FIG. 1A. It is a schematic diagram which shows the aspect of the electron beam irradiation apparatus which concerns on another Embodiment of this invention. It is a perspective view which shows the structure of the roller support device of the electron beam irradiation apparatus which concerns on one Embodiment of this invention. It is a figure explaining the angle variable mechanism. It is a schematic diagram explaining the rotation mechanism of a roller. It is a figure explaining the preferable aspect of a roller and the utilization of a backscattered electron beam.

Hereinafter, the present invention will be described based on the embodiments.

[1] Electron beam irradiation device 1. Basic Aspects First, the basic aspects of the electron beam irradiation apparatus of the present embodiment will be described. FIG. 1A is a schematic view showing a basic aspect of the electron beam irradiation device according to the present embodiment, and is an arrow view in the transport direction of the container. FIG. 1B is a view taken along the line AA of FIG. 1A.

In FIGS. 1A and 1B, reference numeral 1 denotes an in-line electron beam irradiating device, wherein an electron beam irradiating unit 11 that radiates and irradiates an electron beam toward the container C is tilted and supported by the container C. They are arranged so as to face each other so as to be inclined above the transport path 12. In the present embodiment, the electron beam irradiation unit 11 accelerates electrons with low energy or medium energy having an acceleration voltage of 1 MV or less, for example.

The transport path 12 is composed of a plurality of rollers 21 supported by the roller support device 22 in a state where the rotation axis is inclined, and the container C is supported by the flange portion 21c provided at the end of the rollers 21. The container C is placed between two adjacent rollers of the plurality of rotating rollers 21 and is rotated while being conveyed to the downstream side.

Further, in the present embodiment, an angle variable mechanism capable of changing the inclination angle of the rotation axis of the roller 21 with respect to the vertical direction is provided. In FIG. 1A, CL is the center line of the rotation axis of the roller 21, and θ is the inclination angle of the rotation axis with respect to the vertical direction.

With the above configuration, even if the container C is transported in an inclined state, the container C is supported by the flange portion 21c, so that the container C can be transported without being dropped from the device. Then, by transporting the container in an inclined state, the container can be transported in a state where it is not completely upright or completely horizontal, and it is possible to carry the container before and after, especially filling the container with the contents. It becomes easy to combine with such a process. In addition, the height and width of the device can be suppressed, and the device can be miniaturized.

Then, by irradiating the radiation electron beam 11a from the electron beam irradiating unit 11 which is inclined and placed on the roller 21 toward the side surface of the container C which is transported while rotating, the container C is inclined. It is possible to irradiate the entire side surface of the electron beam. Further, since a part of the radiated electron beam 11a wraps around toward the bottom surface B and the top surface T of the container C, it is possible to use one electron beam irradiator while using a low energy or medium energy electron beam irradiator. With one irradiation, the entire outer surface of the bottomed tubular container can be irradiated with an electron beam to perform sufficient sterilization.

Since the electron beam irradiation unit 11 that accelerates and irradiates low-energy or medium-energy electrons is small, the entire electron beam irradiation device 1 can also be miniaturized, which is preferable as an in-line sterilization facility.

Further, in the present embodiment, since the container C can be conveyed while rotating on the roller 21 without being sandwiched between the guide and the roller or gripped by a chuck or the like, the container C can be transported during electron beam irradiation. There is no shaded area where the electron beam is not irradiated. Further, as for the shaded portion of the flange portion 21c with respect to the wraparound electron beam during electron beam irradiation, the shaded portion of the container moves due to the rotation of the roller 21, so that the entire surface of the bottom surface B and the top portion T should be irradiated with the electron beam. Can be done.

Further, in the present embodiment, since the angle variable mechanism is provided as described above, the angle of the radiated electron beam 11a with respect to the container C can be changed by adjusting the inclination angle θ. Even if it is difficult to irradiate the electron beam due to the shape of C and there is a risk that a shaded part may occur, the posture of the container can be freely adjusted by changing the inclination angle θ, and the irradiation point of the electron beam can be adjusted. It is possible to irradiate the shaded area. The specific inclination angle θ is preferably 15 to 90 °.

Further, in the present embodiment, if necessary, a low-energy electron beam is used to irradiate the container filled with the contents in advance before the electron beam irradiation without irradiating the contents with the electron beam. It is also possible to irradiate only the outer surface of the container.

2. 2. Feature of the electron beam irradiation device Next, the feature of the electron beam irradiation device of the present embodiment will be described.

(1) Rollers As shown in FIG. 1A, in the present embodiment, a plurality of rollers 21 that move in the transport direction while rotating are arranged in a transport path 12 arranged so as to face the irradiation direction of the electron beam. It is supported by the roller support device 22 at an inclination angle θ in which the rotation axis is inclined, that is, an acute angle is formed with respect to the vertical direction of the rotation axis, and is arranged at regular intervals. Then, as described above, a flange portion 21c is provided at the end of the roller 21, and the inclined container C is supported from the bottom surface B side.

As a result, the container C can be conveyed while rotating on the roller 21 without being sandwiched between the guide and the roller or gripped by a chuck or the like, so that the container C has a shaded portion during electron beam irradiation. Does not occur. Therefore, with one electron beam irradiating device, even if one irradiation is performed, the electron beam is applied to the entire outer surface of the container C by utilizing the wraparound of the radiated electron beam 11a with respect to the bottom surface B, the top T, and the like. It can be irradiated.

However, when the irradiation direction of the electron beam with respect to the container and the posture of the container are fixed, it is difficult to irradiate the electron beam depending on the shape of the container C, and there is a possibility that a shaded portion may occur. The generation of such shadows can be suppressed by adjusting either the electron beam irradiation direction or the posture of the container, but the method of adjusting the electron beam irradiation direction is described in the electron beam irradiation unit 11. Since the position must be changed, a large space and a complicated mechanism are required, which is not preferable.

On the other hand, when the tilt angle θ of the roller 21 is made variable by providing an angle variable mechanism that does not require a complicated mechanism as in the present embodiment, the tilt angle θ can be freely adjusted by a simple mechanism. Since it can be changed, the posture of the container can be easily and freely adjusted, and a large space is not required.

In the present embodiment, it is preferable that at least a part of the side surface of the portion 21a in contact with the container C of the roller 21 is knurled or satin finished over the entire circumference. By performing such processing, the frictional force between the container C and the side surface of the roller 21 is increased, so that the container C becomes less slippery with respect to the roller 21, and the container C is surely adjusted to the rotating roller 21. The container C can be rotated.

Specific forms of knurling include knurling and fluttering in which the eyes are formed along the axial direction of the roller 21. Moreover, as a form of satin finish, known surface treatment such as etching, sandblasting, and honing can be mentioned. The size of the knurled mesh and the roughness of the satin finish are appropriately determined according to the material of the container, the size of the curvature of the side surface, the surface roughness and the like.

Further, it is preferable that at least a part of the side surface of the portion 21b that does not come into contact with the container C of the roller 21 is mirror-finished over the entire circumference. Specifically, as shown in FIG. 1A, it is preferable that the length of the roller 21 is made larger than the height of the container C, and the side surface of a part of the portion 21b that does not come into contact with the container C is mirror-finished.

As a result, the radiated electron beam 11a is reflected and scattered backward toward the container C in the mirror-finished portion, so that the lid portion of the top T of the container C where the irradiation dose of the radiated electron beam 11a is small, etc. Can also be sterilized by irradiating backscattered electron beams from the mirrored side surface of the roller 21.

In order to obtain such an effect, it is preferable that at least the side surface portion of the roller 21 is formed of a metal having an excellent backscattering function with respect to the electron beam.

Preferred metals include, for example, heavy metals such as tungsten (W) and gold (Au). These metals may be used up to the inside of the roller 21 in a so-called bulk state, but may be used only on the surface portion involved in backscattering, such as surface coating to form a thin film.

(2) Brim portion In the present embodiment, as described above, a flange portion 21c is provided at the end of the roller 21 to support the container C which is conveyed in an inclined state.

(A) Projection width of the collar portion Therefore, the protrusion width of the collar portion 21c is basically a width that allows the container C to be supported by the collar portion 21c in a state where the roller 21 is tilted, but the side surface of the container C. It is preferably smaller than the distance between the container C and the center of rotation of the container C. Specifically, for example, when the container C is cylindrical, it is preferable to make it smaller than the radius of the container C, and the distance is long like a non-cylindrical container, for example, a cylindrical container having an elliptical cross section. For non-constant containers, it is preferably less than the minimum distance.

A shadow is temporarily formed by the flange portion 21c on a part of the bottom surface B of the container C, but when the protrusion width of the collar portion 21c is set as described above, the shadow is formed according to the rotation of the container C. Since the portion moves, the entire bottom surface B can be sufficiently irradiated with the emitted electron beam.

(B) Surface condition and material of the collar portion The surface of the collar portion 21c that comes into contact with the container C is preferably mirror-finished. As a result, the frictional force between the flange portion 21c and the container C when the roller 21 and the container C are rotated is reduced, so that the container C can be rotated smoothly. Further, such mirror surface processing can improve the backscattering function of the electron beam of the flange portion 21c.

Further, at least, the surface in contact with the container C is preferably formed by using a heavy metal such as tungsten (W) or gold (Au), which has an excellent backscattering function with respect to the electron beam.

(3) Roller Support Device FIG. 3 is a perspective view showing the configuration of the roller support device 22, and FIG. 4 is a diagram illustrating an angle variable mechanism.

As shown in FIG. 3, the roller support device 22 has a metal fixing member 22a, a support member 22b, and a roller holding member 22c. The support member 22b is composed of two plate members, and the two plate members are arranged in parallel and vertically at predetermined intervals, and are erected vertically on the outer surface of the fixing member 22a. The roller holding member 22c has a bearing portion that holds the rotating shaft of the roller 21, and a plate material that is erected perpendicular to the surface of the bearing portion facing the fixing member 22a and in the same direction as the rotating shaft of the roller 21. ing.

The plate material of the roller holding member 22c is inserted between the two plate materials of the support member 22b, and is rotatably supported around the fulcrum 22d together with the two plate materials of the support member 22b. As a result, as shown in FIG. 4, the roller 21 can be swiveled along a vertical plane about the fulcrum 22d, and an angle variable mechanism capable of changing the tilt angle θ can be configured.

Then, by providing such an angle variable mechanism and making the inclination angle θ of the roller 21 variable, the angle formed by the radiation direction of the radiated electron beam 11a and the axis of the container C, that is, the irradiation angle with respect to the container C is preferable. It can be adjusted according to the angle.

Protruding portions are provided above and below the roller support device 22, the roller 21 is attached to the upper protruding portion, and the pinion 24a is attached to the lower protruding portion.

(4) Roller Rotation Mechanism FIG. 5 is a schematic diagram illustrating a roller rotation mechanism. In FIG. 5, reference numeral 24b is a rack, which is arranged in parallel along the transport path. As shown in FIG. 5, when the roller support device 22 is carried into the transport path, the pinion 24a meshes with the rack 24b, and the roller support device 22 moves in the transport direction to rotate the roller 21. As a result, the electron beam can be irradiated while rotating the container C.

By combining the pinion 24a and the rack 24b in this way, the rotation mechanism can be made simple and the risk of failure can be reduced. Further, since the rotation speed of the roller 21 is determined by the ratio of the number of teeth of the pinion 24a and the rack 24b, the rotation speed of the roller 21 does not fluctuate even if the transport speed fluctuates. Therefore, for example, in order to adjust the irradiation dose, the rotation speed can be kept constant even when the transport speed is changed.

3. 3. More Preferred Embodiments Next, in the present embodiment, more preferred embodiments will be described.

(1) Reflector FIG. 6 is a diagram illustrating a preferred embodiment of a roller and the use of backscattered electron beams. In FIG. 6, 21a is a portion that contacts the container C of the roller, and 21b is a portion that does not contact. Reference numeral 13 is a reflector.

As shown in FIG. 6, in the present embodiment, if necessary, the reflector 13 may be arranged and the container C may be irradiated with the backscattered electron beams 11b backscattered by the reflector 13. The reflector 13 has a high degree of freedom in the installation position and the scattering direction. Therefore, it is preferable to irradiate a portion that is difficult to irradiate with the backscattering of the roller.

(2) Electron beam irradiation unit The electron beam irradiation unit 11 is installed parallel to a plane whose longitudinal direction is perpendicular to the transport path. At this time, as shown in FIG. 1A, by inclining the longitudinal direction in the same direction as the rotation axis of the roller 21 at an angle of, for example, 15 to 90 ° with respect to the vertical direction, the height direction of the electron beam irradiation unit 11 And the installation space in the width direction can be reduced.

Further, the electron beam irradiating unit 11 is a support device including a position adjusting mechanism for adjusting the height direction and the horizontal direction on a plane perpendicular to the transport path and a radiation direction adjusting mechanism for adjusting the radiation direction of the electron beam. It is preferably supported by. By using the angle variable mechanism, the position adjustment mechanism, and the radiation direction adjustment mechanism, a high degree of freedom can be obtained with respect to the irradiation conditions, so that the electron beam can be used under more suitable conditions for containers of various shapes and sizes. Can be irradiated.

(3) Transport means When irradiating the electron beam, the container C is held in an inclined state in which the inclination angle θ is inclined with respect to the vertical direction as described above. On the other hand, before and after irradiating the electron beam, a step is provided in which it is preferable to hold the container C in an upright state, such as filling the container C with the contents. Therefore, the transport means is configured to change the container held in the upright state on the upstream side of the electron beam irradiation region to the tilted state, while returning the container from the tilted state to the upright state on the downstream side of the electron beam irradiation region. Is preferable.

Specifically, for example, a known mechanism for transferring the container C carried into the upstream end of the transport means from the transport means in the upper process to the roller 21 is installed, while the container C is carried out to the downstream end of the transport means. A configuration is used such as installing a mechanism for transferring the container C from the roller 21 to the transport means in the lower process.

[2] Electron beam irradiation method Next, an electron beam irradiation method for irradiating an electron beam toward a bottomed tubular container using the above-mentioned electron beam irradiation device will be described.

In the present embodiment, the container can be sterilized by irradiating the container with an electron beam by going through the following two steps using the above-mentioned electron beam irradiation device.

That is, the transport process of holding the container in an inclined state so that the side surface faces the irradiation direction of the electron beam and transporting the container from the upstream side to the downstream side, and the electron toward the container to be transported through the transport path. There are two steps, an electron beam irradiation step in which a ray is radiated and irradiated.

Then, through such a process, by irradiating the electron beam toward the bottomed tubular container, as described in the above description of the electron beam irradiating device, not only the side surface of the container but also the bottom surface and the top surface. It is possible to irradiate the electron beam sufficiently. As a result, while using a small electron beam irradiation unit that irradiates a low-energy or medium-energy electron beam at an acceleration voltage of 1 MV or less, the electron beam is efficiently irradiated to the entire outer surface of the tubular container with a single irradiation. be able to.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments. It is possible to make various modifications to the above embodiments within the same and equivalent scope as the present invention.

1 Electron beam irradiation device 11 Electron beam irradiation unit 11a Radiation electron beam 11b Backscattered electron beam 12 Transport path 13 Reflector 21 Roller 21a Part that contacts the container 21b Part that does not contact the container 21c Border 22 Roller support device 22a Fixing member 22b Support member 22c Roller holding member 22d Supporting point 24 Rotating mechanism 24a Pinion 24b Rack C Container B Bottom surface T Top θ Tilt angle CL Center line of rotation axis

Claims (5)

An electron beam irradiator that irradiates an electron beam toward a bottomed tubular container.
A transport means having a transport path for holding the container so that its side surface faces the irradiation direction of the electron beam and transporting the container from the upstream side to the downstream side.
An electron beam irradiating means including an electron beam irradiating unit for accelerating and irradiating electrons toward the container to be conveyed along the transport path is provided.
In the transport means, a plurality of rollers that move in the transport direction while rotating are inclined with respect to the transport direction and arranged at regular intervals, and the container is arranged between two adjacent rollers. It is configured to be transported while rotating,
The roller is provided with a flange portion that protrudes radially from the side surface at one end in the longitudinal direction over the entire circumference of the side surface, and the inclination angle of the rotation axis of the roller with respect to the vertical direction is changed. It is equipped with a variable angle mechanism that can be used.
An electron beam irradiation device characterized in that the irradiation angle of the electron beam with respect to the container is adjusted by adjusting the inclination angle. The electron beam irradiation device according to claim 1, wherein the protruding width of the collar portion is smaller than the distance between the side surface of the container and the rotation center of the container. The electron beam irradiation device according to claim 1 or 2, wherein the surface of the collar portion in contact with the container is mirror-finished. The electron beam irradiation device according to any one of claims 1 to 3, wherein the surface of the collar portion in contact with the container is formed of metal. An electron beam irradiation method for irradiating an electron beam toward a bottomed tubular container using the electron beam irradiation device according to any one of claims 1 to 4.
A transfer step in which the container placed by adjusting the inclination angle of the roller is held so that the side surface faces the irradiation direction of the electron beam at a predetermined angle, and the container is conveyed from the upstream side to the downstream side. ,
It is provided with an electron beam irradiation step of accelerating and irradiating electrons toward the side surface of the container to be transported along the transport path.
In the transfer step, an electron beam irradiation method characterized in that the container arranged between two adjacent rollers is transferred while rotating.

Images