JPH10268100A - Electron beam irradiation device - Google Patents

Abstract

(57) [Problem] To provide an electron beam irradiation apparatus capable of irradiating an electron beam to both the outer surface and the inner surface of a cylindrical container and performing an efficient sterilization treatment. SOLUTION: A first transport unit 41 transports a cylindrical workpiece 2 to a position near an irradiation space 21. First transport unit 4
1 is provided with a holder 62 for holding the workpiece 2 so that the central axis of the workpiece 2 is orthogonal to the transport direction.
The second transport unit 42 is provided below the irradiation space 21,
The floor is provided so as to be inclined so that the processing object conveyed from the first conveying unit 41 moves while rotating. The third transport unit 43 transports the workpiece 2 to an outlet. The first transport unit 41 transfers the workpiece 2 to the second transport unit 42
Is transferred to the irradiation space 21 while rotating.
Pass through. At this time, the entire outer surface of the object 2 is irradiated with the electron beam, and the inner surface is also irradiated with the electron beam transmitted through the object 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam irradiation apparatus used for sterilizing a cylindrical container having a mouth, for example.

[0002]

2. Description of the Related Art In recent years, medical devices such as cylindrical containers having a mouth have been required to sterilize pathogenic bacteria and other microorganisms at a sterilization level in view of health and hygiene. In this case, it is particularly necessary to sterilize not only the outer surface but also the inner surface of the cylindrical container. Conventionally, ultraviolet rays, γ-rays, high-energy electron beams and the like have been used for sterilizing such cylindrical containers.

[0003] Sterilization by ultraviolet light is a method that can be easily carried out. However, although ultraviolet light is suitable for sterilizing the surface, it cannot sterilize the inner surface of the cylindrical container due to its limited permeability. Further, in sterilization using γ-rays or high-energy electron beams, γ-rays or secondary X-rays are generated during processing. Such gamma rays and X-rays are harmful to the human body,
In addition, because of its high penetration power, a special building that shields the equipment with concrete or the like is required to shield it,
The device also becomes large and expensive. Further, in this case, it is necessary to perform batch processing in a separate factory specialized in sterilization, and it is difficult to incorporate a sterilization process into a product manufacturing line.

[0004] Therefore, to sterilize a cylindrical container,
As disclosed in JP-A-61-226050, a method using a low energy electron beam is used.
In this case, the cylindrical container is mounted on a conveyor such as a conveyor in a state where the cylindrical container is tilted. Then, the container is transported in a horizontal direction by a transport device, and when the container passes through a predetermined irradiation area, an electron beam is irradiated from above to perform a sterilization process.

[0005]

When such a low-energy electron beam is applied to a cylindrical container, the electron beam passes through the cylindrical container and travels inside, so that not only the upper outer surface of the container but also
The inner surface can also be sufficiently sterilized. In addition, since the low-energy electron beam wraps around the container to some extent, it is also applied to a portion of the lower outer surface of the container that is not in contact with the transport device. However, since the low-energy electron beam has low permeability, the electron beam traveling inside the container cannot pass through the container again. For this reason, there is a problem that a portion of the lower outer surface of the container that is in contact with the transport device is not irradiated with the electron beam and cannot be sterilized. In this case, by once irradiating the container with the electron beam and then irradiating the electron beam again with the lower side of the container facing upward, the entire container can be surely sterilized. However, this method has poor working efficiency.

[0006] It is also possible to sterilize the entire surface of the container at once by irradiating the container with an electron beam from above and below. However, two electron beam irradiators are required, which is expensive. In addition, a portion that cannot be irradiated with electron beams remains on the lower side of the object to be processed, and a sufficient sterilization process is performed. There is a problem that can not be.

The present invention has been made based on the above circumstances, and is capable of irradiating the entire outer surface and inner surface of a cylindrical container with an electron beam and performing an efficient sterilization process. The purpose is to provide.

[0008]

An electron beam irradiation apparatus according to the present invention for achieving the above object has an electron beam generating means for generating an electron beam and an electron beam generated by the electron beam generating means. Irradiation area to irradiate a substantially cylindrical container, first transport means for transporting the container to the vicinity of the irradiation area so that the central axis of the container is orthogonal to the transport direction,
The floor portion is provided on the downstream side of the first transport unit and below the irradiation area, and the floor is inclined so that the container transported from the first transport unit moves while rotating. And a second conveying means provided.

[0009] The cylindrical container is conveyed by the first conveying means and sent to the vicinity of the irradiation area. When the first transport means transports the container to the second transport means, the container passes while rotating on the floor because the floor of the second transport means is inclined. Therefore, when the container passes through the irradiation region, the container is rotating, so that the entire outer surface of the container is irradiated with the electron beam, and the electron beam transmitted through the container is also irradiated with the electron beam on the inner surface.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an electron beam irradiation apparatus according to an embodiment of the present invention, FIG. 2 is a schematic circuit diagram of an electron beam generator of the electron beam irradiation apparatus, and FIG. FIG.

The electron beam irradiator shown in FIG. 1 is used for polymerization and cross-linking on the surface of the object, sterilization of the object, etc.
It is used for various purposes. In particular, in the present embodiment, a case where such an electron beam irradiation apparatus is used for sterilization of an object to be processed is considered. As the object 2 to be processed,
As shown in FIG. 3, a cylindrical container having a mouth is used. The diameter of the body of such a cylindrical container is 5 to 50 mm. Further, this container is used as an eye drop container, and it is necessary to sterilize not only the outer surface but also the inner surface.

As shown in FIG. 1, the electron beam irradiation device includes an electron beam generator 10, an irradiation chamber 20, an irradiation window 30, and a transport means 40. Electron beam generator 10
Is a terminal 11 for generating an electron beam, and a terminal 1
And an acceleration tube 12 for accelerating the electron beam generated in 1 in a vacuum space (acceleration space). The inside of the electron beam generating unit 10 is 1.3 × 10 3 by a pump or the like (not shown) in order to prevent electrons from colliding with gas molecules and losing energy, and to prevent oxidation of the filament 11a.
^{-4 to} 1.3 × 10 ^-5 Pa is maintained in a vacuum. Terminal 11 is a linear filament 11 that emits thermoelectrons.
a and a gun structure 11b supporting the filament 11a
And a grid 11c for controlling thermoelectrons generated by the filament 11a.

Further, as shown in FIG.
0, a heating power supply 16a for heating the filament 11a to generate thermoelectrons, a control DC power supply 16b for applying a voltage between the filament 11a and the grid 11c, a grid 11c and the irradiation window 30. And an acceleration DC power supply 16c for applying a voltage (acceleration voltage) to the window foil 31 provided in the power supply.

The irradiation chamber 20 includes an irradiation space (irradiation area) 21 for irradiating an object with an electron beam. The inside of the irradiation chamber 20 is kept in a nitrogen atmosphere. This is because, in the case where the surface treatment is performed as in the present embodiment, it is necessary to prevent the target reaction from being stopped by oxygen adhering to the reaction site of the object to be processed formed by irradiation with the electron beam. Because. The object to be processed is moved by the transfer means 40 in the irradiation chamber 20. In addition, the periphery of the electron beam generator 10 and the irradiation chamber 20 is covered with lead so that X-rays that are generated secondarily during electron beam irradiation do not leak to the outside.

The irradiation window 30 has a window foil 31 and a window frame structure 32 for cooling and supporting the window foil 31. The window foil 31 is provided between the vacuum atmosphere in the electron beam generator 10 and the irradiation chamber 2.
0 to separate the nitrogen atmosphere.
The electron beam is taken out into the irradiation chamber 20 through the.
A metal foil such as a Ti foil is used for the window foil 31. Usually, a Ti foil having a thickness of about 13 μm is most often used because of its mechanical ease of handling.

In this embodiment, as described later,
Since the floor of the second transfer section 42 of the transfer means 40 is provided at an angle, the electron beam generated by the electron beam generation section 10 irradiates the workpiece moving in the second transfer section 42 vertically. As such, the terminal 11 and the irradiation window 30 are also inclined and attached along the inclination of the floor. Thereby, the window foil 31
The distance between the object and each position of the object passing through the irradiation chamber 21 becomes constant, and the object can be uniformly irradiated with the electron beam.

The filament 11 is supplied by a heating power supply 16a.
When the filament 11a is heated through an electric current, the filament 11a emits thermoelectrons, and the thermoelectrons are drawn in all directions by the control voltage of the control DC power supply 16b applied between the filament 11a and the grid 11c. this house,
Only those that have passed through the grid 11c are effectively extracted as electron beams. The electron beam extracted from the grid 11c is accelerated in an acceleration space in the accelerating tube 12 by the acceleration voltage of the DC power supply 16c for acceleration applied between the grid 11c and the window foil 31, and then accelerated. The object to be processed, which passes through the irradiation chamber 20 and passes through the irradiation window 20 below the irradiation window 30, is irradiated.

Normally, the heating power supply 16a and the acceleration DC power supply 16c are set to predetermined values, and the control DC power supply 1
The beam current is adjusted by making 6b variable. In general, in an electron beam irradiation apparatus, the dose absorbed by an object to be processed is proportional to the beam current. Therefore, by changing the beam current, the absorbed dose of the electron beam can be adjusted. In this embodiment, in order to realize a low energy electron beam, the acceleration voltage is set to 100 kV or more and 500 kV or more.
Set within the range of kV or less.

Next, the transport means 40 used in the electron beam irradiation apparatus of the present embodiment will be described. 4 is a schematic plan view of the transfer means, FIG. 5 is a schematic side view of the transfer means shown in FIG. 4 when viewed from the side, and FIG. 6 is an A view of the transfer means shown in FIG.
FIG. 7 is a schematic cross-sectional view taken in the direction of the arrow A. FIG. 7 is a view for explaining a state in which the workpiece is transferred from the first transfer unit to the second transfer unit by the transfer unit.

As shown in FIGS. 1 and 4 to 6, the transport means 40 includes a first transport section 41, a second transport section 42,
And a third transport section 43. The transfer means 40 is provided in the irradiation chamber 20. The first transport unit 41 transports the workpiece horizontally to the vicinity of the irradiation space 21, and in the present embodiment, the first transport unit 41
Use a chain conveyor.

As shown in FIGS. 4 to 7, the first transport section 41 has a chain 61, a holder 62, a sprocket 63, a belt 64, and a motor 65. The motor 65 is for driving the chain 61. The drive of the motor 65 is transmitted to the sprocket 63 via the belt 64, and the sprocket 63 rotates, so that the chain 61 moves. A holder 62 for holding the workpiece 2 is attached to the chain 61. An elongated tub (trough) is used as the holder 62,
The cross section of the holder 62 by a plane perpendicular to the direction orthogonal to the transport direction of the first transport unit 41 is formed in a substantially U-shape whose side part is open upward. As shown in FIG. 4, one holder 62 can hold two workpieces 2 so that the central axis of the workpiece 2 is orthogonal to the transport direction.

The second transport section 42 is a table provided below the irradiation window section 30, and has a floor section 42a which is inclined and mounted as shown in FIG. The reason why the floor portion 42a of the second transport portion 42 is provided to be inclined is that the first transport portion 4
The object 2 conveyed from 1 rotates in the irradiation space 2 while rotating.
1 in order to pass through. The inclination angle is set so as to be within a range of 5 degrees or more and 50 degrees or less with respect to the horizontal direction. This is for the following reason. If the inclination angle is smaller than 5 degrees, the workpiece 2 does not roll well,
This is because a large number of workpieces 2 may be clogged in the second transport unit 42, while if the inclination angle is greater than 50 degrees, the workpieces 2 may not rotate and slide sideways. In the present embodiment, as shown in FIG. 5, the inclination angle of the second transport unit 42 is set to 25 degrees.

The second transport section 42 also functions as a beam collector for absorbing electron beams. Second transport unit 42
Aluminum is used as the material of the. Aluminum was used because a light element more easily absorbs an electron beam and generates less X-rays. Second transport unit 42
Is constantly irradiated with an electron beam, so that the second transport unit 42 is cooled by a cooling device (not shown). In addition, the surface of the second transport unit 42 is in a Rinshi place without a surface finish such as mirror finishing. By making the surface rough, the object 2 can be reliably rotated.

The third transport section 43 transports the workpiece 2 irradiated with the electron beam in the second transport section 42 to an outlet. The third transport section 43 is also attached at an angle. As shown in FIG. 5, the inclination angle with respect to the horizontal direction is set to 30 degrees for the first half of the third transport unit 43, and the inclination angle is set to 45 degrees for the second half. Guides 43a are provided on both sides of the third transport section 43. By providing such a guide 43a, the object 2 is reliably conveyed toward the outlet without falling down from the side surface, no matter how it rolls.

In this embodiment, the first transport unit 41
Is configured to transport the workpiece 2 as close to the irradiation area 21 as possible. That is, as shown in FIG.
The front end of the first transport unit 41 in the transport direction and the second transport unit 4
Wherever possible the distance D ₁ of the two central positions are designed so that short. This is because the workpiece 2 transported from the first transport section 41 to the second transport section 42 rolls linearly and stably near the point where the workpiece 2 starts rolling. This is to allow the light to pass through the irradiation space 21 while being in a stable state. The third transport unit 4
Distance D ₂ between the center position of the rear end portion of the conveyance direction and the second conveying part 42 of 3 is also designed to be as short as possible.
This is because the workpiece 2 transported to the second transport unit 42
This is because there is a risk that the vehicle will bend and roll if it is far from the point where the vehicle started rolling. Therefore, it is desirable to transport the workpiece 2 to the third transport unit 43 having the guide 43a when the workpiece 2 is rolling stably.

Next, the operation of the electron beam irradiation apparatus of this embodiment will be described. First, the workpiece 2 is transferred to the first transport unit 4.
When the workpiece 2 is placed on the first holder 62, the workpiece 2 is transported by the first transport unit 41 and sent to the front of the second transport unit 42.
Then, when the first transport unit 41 transports the workpiece 2 to the second transport unit 42, the workpiece 2 falls to the second transport unit 42. Since the floor portion 42a of the second transport section 42 is attached at an angle, the workpiece 2 passes through the irradiation space 31 while rotating the second transport section 42. As described above, since the object 2 is rotating, the entire outer surface of the object 2 is irradiated with the electron beam, and the electron beam transmitted through the object 2 causes the inner surface of the object 2 to be irradiated with the electron beam. A line is illuminated. As a result, the entire outer surface and inner surface of the workpiece 2 are irradiated with the electron beam. Thereafter, the workpiece 2 advances while rotating the second transport unit 42 and moves to the third transport unit 43. Then, the workpiece 2 is transported to the exit while rolling on the third transport section 43 and is carried out to the outside.

Next, the present inventors conducted an experiment for confirming the effect of the sterilization treatment by such an electron beam irradiation apparatus. In this experiment, the diameter of the mouth was about 10 m as an experimental sample.
m, an eye drop container having a body diameter of about 20 mm was used.
In addition, an electron beam irradiation device CB250 / 15 / 180L manufactured by Iwasaki Electric Co., Ltd. was used as the electron beam irradiation device. The irradiation conditions of the electron beam are an acceleration voltage of 250 kV and a beam current of 5 mA. Then, the first transport unit 41 is operated so that 100 experimental samples can be processed in one minute.
Transfer speed was set.

An experiment was conducted according to the following procedure. First, labels are attached to the outer surface and the inner surface of the experimental sample at the mouth and the trunk, respectively, along the circumferential direction. Such a label changes color from yellow to red when it receives the energy of an electron beam. Next, a number of experimental samples are placed on the first transport unit 41 of the electron beam irradiation device, and the experimental samples are irradiated with electron beams.

As a result of this experiment, all the labels of each experimental sample were uniformly discolored to red. Therefore,
It was confirmed that the use of the electron beam irradiation apparatus of the present embodiment can sufficiently sterilize both the inner surface and the outer surface of the object. In the electron beam irradiation apparatus of the present embodiment, the first transport unit that transports the workpiece to the vicinity of the irradiation space, while rotating the workpiece transported from the first transport unit below the irradiation space. By providing a second transport unit provided with an inclined floor so as to move, the workpiece transported by the first transport unit to the vicinity of the irradiation space is transported to the second transport unit After being rotated, it passes through the irradiation space while rotating, so that the entire outer surface of the object is irradiated with the electron beam, and the electron beam transmitted through the object is also irradiated with the electron beam on the inner surface. Sterilization can be efficiently performed on the outer surface and the inner surface of the workpiece.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the invention. For example, in the above embodiment, guides may be provided on both sides of the second transport unit. Thus, it is possible to reliably prevent the workpiece from dropping from the side surface of the second transport unit.

Further, in the above-described embodiment, the case where the table is used as the second transport unit has been described. However, a belt conveyor or the like may be used as the second transport unit. Furthermore, in the above-described embodiment, the case where the irradiation window and the like are attached at an angle in order to vertically irradiate the processing target with the electron beam emitted from the electron beam generation unit has been described. There is no need to provide it at an angle.

[0032]

As described above, according to the present invention, the first transport means for transporting the cylindrical container to the vicinity of the irradiation area, and the first transport means for transporting the cylindrical container below the irradiation area from the first transport means. The container transported to the vicinity of the irradiation area by the first transporting means is provided with the second transporting means provided with the floor portion inclined so as to move while rotating the container. After being conveyed to the conveying means, while passing through the irradiation area while rotating, the entire outer surface of the container is irradiated with the electron beam, and the electron beam transmitted through the container is also irradiated with the electron beam on the inner surface, An electron beam irradiation apparatus capable of efficiently performing sterilization processing on the outer surface and the inner surface of the container can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electron beam irradiation apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic circuit diagram of an electron beam generator of the electron beam irradiation device.

FIG. 3 is a diagram for explaining an object to be processed used in the present embodiment.

FIG. 4 is a schematic plan view of a transport unit of the electron beam irradiation device of the present embodiment.

FIG. 5 is a schematic side view of the transfer unit shown in FIG. 4 when viewed from the side.

FIG. 6 is a schematic cross-sectional view of the conveying means shown in FIG.

FIG. 7 is a view for explaining a state in which an object to be processed is transferred from a first transfer section to a second transfer section by the transfer means.

[Explanation of symbols]

 2 Workpiece 10 Electron beam generator 11 Terminal 11a Filament 11b Gun structure 11c Grid 12 Accelerator tube 16a Power supply for heating 16b DC power supply for control 16c DC power supply for acceleration 20 Irradiation room 21 Irradiation space 30 Irradiation window 31 Window foil 32 Window frame structure 40 Conveying means 42a Floor part 41 First conveying part 42 Second conveying part 43 Third conveying part 43a Guide 61 Chain 62 Holder 63 Sprocket 64 Belt 65 Motor

Claims (6)

[Claims] 1. An electron beam generating means for generating an electron beam, an irradiation area for irradiating the substantially cylindrical container with the electron beam generated by the electron beam generating means, and a central axis of the container being orthogonal to a transport direction. First transport means for transporting the container to the vicinity of the irradiation area in such a manner as to be provided downstream of the first transport means and below the irradiation area, and the first transport means An electron beam irradiation apparatus, comprising: a second conveying means provided with an inclined floor so that the container conveyed from the means moves while rotating. 2. An electron beam irradiation apparatus according to claim 1, wherein said first transport means is provided with a holding means for holding said container. 3. The electron beam irradiation according to claim 1, wherein an inclination angle of a floor portion of the second transport means is set within a range of 5 degrees or more and 50 degrees or less with respect to a horizontal direction. apparatus. 4. The apparatus according to claim 1, further comprising a third transport unit provided downstream of the second transport unit and configured to unload the container transported by the second transport unit to an outlet. An electron beam irradiation apparatus according to any one of claims 1 to 3. 5. The electron beam irradiation apparatus according to claim 1, wherein the electron beam is accelerated by the electron beam generator at a voltage of 100 kV or more and 500 kV or less. 6. The container has a mouth portion,
6. The electron beam irradiation apparatus according to claim 1, wherein a diameter of the body is in a range of 5 mm or more and 50 mm or less.