JPS649218B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of sterilizing already formed containers among packaging materials using UV (ultraviolet light).

Generally, chemical methods are used to sterilize packaging materials.
Examples include H ₂ O ₂ (hydrogen peroxide) immersion sterilization and EOG (ethylene oxide gas) sterilization. H ₂ O ₂ sterilization has been practiced for a long time and has become a common method.

If the packaging material is in sheet form, immersion in H ₂ O ₂ is sufficient, and in-line sterilization inside the packaging machine is possible;
H ₂ O ₂ provides reliable sterilization including cleaning effects. In addition, if the packaging material is a molded container, it is difficult to dry and handle it after immersion, so H ₂ O ₂
Currently, sterilization is done by spraying, etc.
However, since the H ₂ O ₂ method uses wet sterilization, H ₂ O ₂ may remain in the product if drying is insufficient, and even if it is below the detection level, H ₂ O ₂ is carcinogenic. Due to the suspicion of

Furthermore, EOG is gaseous and uses batch sterilization, regardless of the form of the packaging material, which is inefficient. Additionally, it may remain in the product, making it difficult to use.

Physical sterilization methods include gamma rays, EB (electron beam),
UV sterilization, etc. Gamma ray sterilization is an effective sterilization method that allows sterilization in the final step, similar to gas sterilization, because gamma rays penetrate plastic packaging materials. However, even with this method, there is a decrease in heat sealing strength after irradiation with gamma rays and deterioration in physical properties such as odor.
In addition, cobalt-60 is often used as a radiation source, which is difficult to handle and has a limited period of use (half-decreased
(2013), the need for a shield, and the radiation allergy that is unique to Japanese people, making him socially handicapped.

On the other hand, by increasing the acceleration voltage of electron beams,
Due to its increased permeability, packaging materials such as sheets and molded products can also be sterilized, making it possible to use it in-line. However, as the accelerating voltage increases, X-rays are generated from the metal parts exposed to EB irradiation, making it difficult to use due to the problem of resistance and the need to exhaust O ₃ generated as a byproduct of EB irradiation.

Compared to other forms of radiation, UV sterilization has less impact on the human body and is easier to handle. In addition, because it is a dry sterilization method, there is no residual chemical or other chemicals, so there are fewer problems. In the past, UV lamps were rarely used alone due to their weak sterilizing power and were used as an auxiliary means, but in recent years, UV lamps with strong sterilizing power have been developed and have become so powerful that they pose no problem in practical use.

However, since it is a rod-shaped lamp, it is suitable for sterilizing sheet-like packaging materials, but is not suitable for molded containers whose distance from the lamp is not constant. Taking a cup as an example, if a sufficient amount of radiation for sterilization is applied to the bottom of the cup, which is located at a greater distance from the lamp, the flange will be over-irradiated, resulting in reduced heat seal strength, discoloration, etc., and the product will no longer be viable. When used as a standard, rod-shaped lamps were difficult to use for molded containers, such as poor sterilization at the bottom.

In view of the above, there is currently a need for a simple and effective means of sterilizing molded containers.

The present invention was made in view of the current situation, and
Molded containers are sterilized using UV light, and the disadvantages of conventional UV methods are overcome by using round lamps and circle-shaped lamps that match the shape of the container rather than rod-shaped UV lamps. This is what I am trying to do.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows the process of sterilizing preformed containers 10 by UV irradiation while transporting the preformed containers 10 from their collection location to the filling device. In the figure,
Reference numeral 12 denotes a conveying plate constituting the conveyor.

The transport plate is provided with a hole 14 as shown in FIG. 2, into which a preformed container is inserted and supported. The container is in this case provided with a flange 16 by which it is supported on the conveyor plate.

The conveyance plate 12 is intermittently traveling, and UV lamps 18 and 20 are installed above and below a predetermined stopping position thereof via appropriate vertical drive means.

The upper UV lamp 18 has a round shape with a single cap, and is sized so that it can be inserted into a container. A plurality of them are fixed to the support body 22 and are configured to move up and down together with the support body. Here, the above-mentioned round UV lamp is constructed as shown in Fig. 3. That is, in the figure, 24 is an inner tube, 26 is an outer tube,
28 is a cathode, and 30 is an anode. Mercury neon is contained in the inner and outer tubes, and the outer tube 26 is made of quartz glass. Therefore, ultraviolet rays are irradiated by the discharge between the cathode and anode.

The lower UV lamps 20 are configured in a circular shape, and are installed singly or in combination so as to surround the outer wall of the container, and are movable up and down as a unit. If a plurality of tubes are installed, it is desirable to make the diameters different according to the taper of the side wall of the container.

In addition, the UV lamps 18 and 20 are as shown in Figure 4.
It is covered with a reflective plate to improve the efficiency of UV irradiation. The reflector plate 32 for the upper lamp is configured in the shape of a dish, and the reflector plate 34 for the lower lamp is configured in the shape of a pot. The reflector 32 is fixed to the support 22, and the reflector 34 is fixed to a support (not shown).

Then, a plurality of containers 10 are taken out in a line from the stacking section of preformed containers in the aseptic filling and packaging apparatus, and are dropped into the holes 14 of the conveyor plate 12 constituting the conveyor, as shown in FIGS. 1 and 2. After that, it is transported between the upper and lower UV lamps 18 and 20. The conveyance plate moves intermittently, and when it pauses, the upper support 22 descends and the lower support rises, and as shown in FIG. At the same time, a circle-type UV lamp 20 surrounds the container from the outside and irradiates the outer wall surface with UV. After being irradiated with a predetermined amount of UV,
Each support returns to its original position and each UV lamp 18, 2
0 moves away from the container. Then, the containers in the rear row are moved again and the same operation is repeated for them.

The sterilized container is then filled with contents, hermetically sealed with a previously sterilized lid, and then discharged.

As described above, in the present invention, a round UV lamp is inserted into the container, and the outside of the container is surrounded by a circle-shaped UV lamp, so that the distance between the molded container wall and the lamp can be shortened, resulting in uniform Powerful irradiation is possible.

Additionally, by using a reflector on the top of the lamp, UV rays will not leak to the outside of the container, allowing efficient use of irradiation.

Conventionally, when sterilizing molded containers, a rod-shaped UV lamp with strong power was used, and it was more efficient to prepare containers for the length of the UV lamp, so sterilization was carried out to match the length of the lamp. The principle was to have multiple rows. However, it has the disadvantage that not all UV light can be used effectively due to mechanical constraints, cases in which it is not possible to obtain as much UV as possible due to the diameter of the container flange, and loss between containers. Furthermore, since there is a difference in irradiation at the flange, side wall, and bottom, problems remain with respect to sterilization and heat sealability. However, according to the present invention, since uniform irradiation is achieved as described above, there is no such drawback.

In addition, since it is efficient, only the bottom power is needed, and the cooling mechanism used conventionally can be simplified.

Therefore, more reliable sterilization and energy-saving sterilization can be performed.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of the apparatus used in the method of the invention. FIG. 2 is a sectional view taken along the - line in FIG. 1. FIG. 3 is an explanatory diagram of an example of a round UV lamp. FIG. 4 is a vertical cross-sectional view of a container being sterilized with a UV lamp.

Claims (1)

[Scope of Claims] 1. While a pre-formed container is running while supporting its flange, a round UV lamp is closely inserted into the container to sterilize the inner wall surface of the container, and to inject heat around the outer periphery of the container. A sterilization method using ultraviolet rays, characterized by sterilizing the outer wall surface of the container by bringing a Klein-type UV lamp close to the container, and then moving the round-shaped UV lamp and the circle-type UV lamp away from the container. 2. The ultraviolet sterilization method according to claim 1, characterized in that the round and circular UV lamps are covered with a reflective plate.