JPS6326013B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a sterile packaging machine that uses an electron beam irradiation device in a packaging machine that uses a packaging material composed of a bottom material and a lid material sheet. .

[Prior Art] Generally, chemical methods for sterilizing packaging materials include H ₂ O ₂ immersion sterilization and EOG sterilization. _{H2O2 _}
Sterilization is a method that has been used for a long time, but in recent years, it has become difficult to use because of the problem of a small amount of H ₂ O ₂ remaining in the product, and EOG sterilization is gaseous, so batch sterilization is required. Therefore, in-line sterilization is impossible, and furthermore, it may remain in the product, making it difficult to use.
Physical sterilization methods include gamma rays and UV sterilization, but gamma ray irradiation causes a decrease in heat seal strength and deterioration in physical properties such as odor, and also causes psychological anxiety due to radiation exposure. In addition, although UV sterilization is easier to handle than other radiations, its sterilizing power is generally weak, and even with the powerful UV lamps developed in recent years, its sterilizing power only affects the surface of the packaging material. It only works on the area, and if there is dust etc. on the area, it will not sterilize that area.
Complete sterilization could not be expected.

In recent years, a sterilization method using electron beam irradiation has been developed, but because it uses mainly low energy, it is possible to sterilize the surface, but it is insufficient to sterilize the inside and back surfaces. However, with the advancement of high energy, it has become possible to sterilize even relatively thick objects.
As energy becomes higher, power sources become larger, shielding devices become more complex, and equipment costs increase, so improvements in the efficiency of their use have been desired.

In other words, when conventionally sterilizing two sheets, the lid material and the bottom material, when using a low-energy electron beam irradiation device, four devices are required if one device is installed facing each other on the front and back of each sheet. Furthermore, even when one high-energy electron beam irradiation device is used to process both sides of one sheet, two devices are required. Furthermore, in order to create a device that can superimpose two sheets and sterilize them by irradiation, a more powerful electron beam irradiation device is required, which inevitably increases the size of the device and the equipment cost.

[Objective] The present invention aims to improve the above-mentioned drawbacks and provide a sterilization device that efficiently uses an electron beam irradiation device.

[Structure] The apparatus for sterilizing packaging materials using an electron beam according to the present invention sterilizes two packaging materials almost at right angles using two small-diameter rollers whose distance between their axes is smaller than the beam diameter of the sterilizing electron beam. Guide the bending and make it fit tightly.
The sterilizing electron beam is scanned in the width direction of the packaging material at the start of close contact, and is irradiated so as to form an irradiated part substantially perpendicular to each packaging material.

[Examples] Examples of the present invention will be described below with reference to the drawings.

The beam diameter of this type of electron beam irradiation is not a very sharp spot, and is relatively large at 20 to 30 mmφ. This is intended to sterilize two packaging materials at the same time using one electron beam irradiation device. That is, the sterilizing electron beam spot 1 shown in FIG. 1 in the width direction of the packaging materials 2 and 3, it becomes possible to sterilize the two packaging materials 2 and 3 simultaneously with one device.

To explain this in detail, as shown in Figure 2 [Figure A is a side view and Figure B is a perspective view], packaging materials 2 and 3 are placed facing each other from the left and right with their inner surfaces facing upward. 2 by the close guide rolls 4 and 5.
The sheets are put together and guided downward. A sterilizing electron beam irradiation device 6 is provided above the portion that is tightly joined by the contact guide rolls 4 and 5, and from this, an electron beam spot is irradiated and scanned in the width direction of the packaging materials 2 and 3. There is. With this arrangement, the electron beam spot is as shown in Figure 1C [view looking down from the direction of the irradiation device 6 in Figure 2A].
As shown in FIG. 2, the electron beam spot 1 simultaneously irradiates and scans the packaging materials 2 and 3, thereby exerting a sterilizing effect on both at the same time. Even if the electron beam is made into a semicircular spot, there will be no change in its penetrating sterilizing power. The packaging materials 2 and 3 that have been sterilized by electron beam irradiation are guided by a guide roll 7 in a close contact state, and then separated into two pieces by a guide roll 8 again and guided to a sterile packaging machine where processing and filling operations are performed. Note that the reference numeral 9 is also a guide roll.

When applying electron beam irradiation to the two packaging materials 2 and 3, as shown in FIG.
If the diameter of 5' is increased, the electron beam spot 1 will no longer hit the surfaces of the packaging materials 2 and 3 at right angles, and as a result, it will not be possible to maintain the perpendicularity between the electron beam and the facing surface, which is the optimum irradiation condition. As shown in FIG. 2, the distance between the axes of the small-diameter guide rolls 4 and 5 is set to be smaller than the beam diameter so as not to cause folding or bending of the packaging material.

An example of the apparatus according to the present invention is shown in FIG. 4, in which the irradiation processing part is covered with a shielding plate 10 made of lead or the like to prevent the electron beam from the irradiation device 6 from leaking to the outside. After line sterilization, the packaging material 2 (lid material) and packaging material 3 (bottom material) are processed and filled with the contents in a conventional aseptic packaging machine (in a sterile room with positive pressure inside). In order to carry out this process, the stainless steel plate 11 is fed through a passage in a conventionally used stainless steel plate 11.

[Effect] As explained above, the present invention abuts the two packaging materials 2 and 3 to be sterilized from the left and right sides at almost right angles, bends and guides them, and irradiates the part where they are brought into close contact with the electron beam spot 1. By scanning, two packaging materials can be sufficiently sterilized at the same time with one irradiation device, so the irradiation device can be used efficiently. In this case, two packaging sheets can be sterilized with one irradiation device that can sterilize the front and back sides of the packaging sheets with electron beams, but the surface that contacts the contents of the packaging sheet is always the top irradiated surface. It has a strong sterilizing ability, so even if the packaging material is thick and difficult for electron beams to pass through, if you only need to sterilize the surface that comes into contact with the contents,
This device can now be used. It is also possible to sterilize the inner surface of packaging materials (materials) such as pouches and back-in boxes by irradiating them, and by performing side seals immediately after irradiation, sterile pouches and back-in boxes can be created. The advantage of this is that it is suitable for cases where low energy and low radiation doses are desired as odor countermeasures.

In this way, it is possible to sterilize the front and back sides of two packaging materials at an energy level that allows transmission through one sheet, reducing equipment investment, simplifying the arrangement of shielding plates, and making the device effective as an energy-saving device.

[Brief explanation of drawings]

FIG. 1A is a diagram showing an electron beam spot, and FIG. 1B is an explanatory diagram of how to use the electron beam spot according to the present invention.
2C is a top view showing the state in which the electron beam spot according to the present invention is irradiated onto a packaging material, FIG. 2A is a side view of the apparatus according to the present invention, FIG. 3B is a perspective view, and FIG. FIG. 4 is an explanatory diagram showing a preferred embodiment; FIG. 4 is an explanatory diagram showing an unpreferred example; and FIG. 1... Electron beam spot, 2, 3... Packaging material (lid material, bottom material), 4, 5... Guide roll, 6... Electron beam irradiation device, 10... Shielding plate.

Claims (1)

[Scope of Claims] 1. Two small-diameter rollers whose center distance is smaller than the beam diameter of a sterilizing electron beam are used to bend and guide two packaging materials almost perpendicularly to each other and bring them into close contact;
The sterilizing electron beam is scanned in the width direction of the packaging material at the point where the adhesion starts, and is irradiated so that the irradiated part is almost perpendicular to each packaging material. Material sterilization equipment.