JPH03212333A - Sterilizing method of packing vessel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a method for sterilizing packaging containers, and more specifically, for packaging containers such as bottles, plastic bottles, cartons, or pop-up containers for food products. The present invention relates to a method for sterilizing packaging containers in which a sterilizing agent is uniformly applied to the outer surface of the container.

[Prior Art] Generally, in packaging containers such as food containers,
Particularly in aseptic filling systems, packaging containers must be sterilized prior to use.

Therefore, in the past, hydrogen peroxide (H2O
2) was commonly used to apply it to packaging containers by spraying. In this case, a two-fluid nozzle was used as a sprayer, and compressed air (2 to 3 kg/cut) and an aqueous hydrogen peroxide solution were mixed and sprayed through a hole with a diameter of 1 m or less. Therefore, when spraying from a close distance, there is a problem in that the diameter of the adhered particles is extremely different between the center and the periphery, and when sprayed from a distance, the adhesion efficiency is poor and space is also a problem. Furthermore, in the case of the inner surface of a container, it can be expected that the material that bounced off the bottom will also adhere to the inner surface, but this was particularly difficult in the case of the outer surface of a cylindrical container.

Therefore, as shown in Figure 10, a method has been adopted in which a room temperature or heated aqueous solution of hydrogen peroxide is applied from the side of the packaging container placed on a horizontally rotating table a using a spray C. has been done.

[Problems to be Solved by the Invention] However, even in the method described above in which hydrogen peroxide is applied from the side with Spray C while rotating the packaging container, the adhesion efficiency cannot be improved, and the packaging There was a problem in that the adhesion to the head d and bottom e of the container was insufficient compared to the middle part of the container (see Fig. 11).

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a method for sterilizing packaging containers that allows a sterilant to be easily and efficiently applied to the outer surface of the packaging container, and also to apply it uniformly. It is something to do.

[Means for Solving the Problems] In order to achieve the above object, the method for sterilizing packaging containers of the present invention firstly vaporizes a liquid sterilant and then condenses it in the air to form a fine sterilizer. The present invention is characterized in that a mist is generated, the generated sterilant mist is sprayed from a direction other than perpendicular to the outer surface of the packaging container, and is attached along the outer surface of the packaging container, and Second
Injecting the sterilant mist generated as described above toward the inner surface of the cylindrical body surrounding the outer periphery of the packaging container,
It is characterized in that it is attached along the outer surface of the packaging container.

In this invention, the spraying may be carried out in any manner as long as the sterilant mist is sprayed from a direction other than perpendicular to the outer surface of the packaging container, but if the spraying means is a single nozzle; It is better to spray the sterilant mist while rotating the packaging container horizontally. In this case, if the number of nozzles is plural, preferably four or more,
Sterilizing agent can be applied uniformly even when the packaging container is fixed.

Furthermore, when the outer circumference of the packaging container is lined with a cylindrical body, the sterilant can be efficiently adhered to the outer surface of the packaging container by spraying a sterilant mist onto the inner surface of the cylindrical body. It is preferable to increase the temperature of the inner surface of the cylindrical body to prevent the sterilant mist from condensing on the inner surface of the cylindrical body.

In this case, the cylindrical body may be made of metal or plastic as long as it has corrosion resistance against sterilizing agents, but if the temperature of the cylindrical body is to be increased, it may be A metal with high conductivity is preferable.

[Function] With the above configuration, after the liquid sterilant is heated to the boiling point or higher by the heating means and completely vaporized,
When the sterilant mist is condensed in the air and generated in the form of a mist, and is gently sprayed onto the outer surface of the packaging container, the sterilant mist flows along the outer surface of the packaging container and is evenly deposited.

In addition, by spraying the sterilant mist toward the inner surface of the cylindrical body surrounding the outer periphery of the packaging container, the sterilant mist does not scatter anywhere other than the inside of the cylindrical body, increasing the mist density in the space. Since the flow along the packaging container is further enhanced, the adhesion efficiency is improved.

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

◎First Embodiment FIG. 1 is a schematic explanatory diagram of a first embodiment of a sterilizing device for packaging containers according to the present invention, and FIG. 2 is a sectional view of the main parts of the sterilizing device.

The sterilizing device according to the present invention includes a sterilizing agent supply section 10 that supplies an aqueous solution of hydrogen peroxide (H202), which is a liquid sterilizing agent.
and a vaporizing section 20 which is equipped with a heating means 26 and which heats the sterilizing agent supplied from the sterilizing agent supplying section 10 to a temperature higher than its boiling point and vaporizes it; The main part is constituted by the injection means 30 for injection.

In this case, the sterilizing agent supply section 10 is of a type in which the aqueous hydrogen peroxide solution 12 is supplied into the chamber of the vaporization section 20 by a pump 16 from a tank 14 containing the aqueous hydrogen peroxide solution 12 .

It should be noted that the sterilizing agent supply unit 10 does not necessarily have to be of the above type, but may be configured as a two-fluid sprayer having a liquid inlet for supplying an aqueous hydrogen peroxide solution and an air inlet for spraying for supplying compressed air. It may be something.

The vaporization section 20 includes a heating means 26 disposed in a chamber 24 made of a metal material 22, an air flow introduction port 28 opened in a part of the chamber 24, and an air flow generation section 32 such as a compressor.
and are connected via a pressure feed pipe line 34. in this case,
By arranging the heater 36 in a part of the pressure-feeding conduit 34, the airflow can be forcedly fed to the vaporization section 20 in a heated state. In this case, the heating means 26 is connected to the vaporizing section 2.
Any device may be used as long as it heats the liquid sterilant supplied into the chamber 24 above its boiling point, such as a panel-shaped heating element stretched over the inner wall of the chamber 24, or a panel-shaped heating element that heats the liquid sterilant supplied into the chamber 24 to a temperature above the boiling point. A panel-shaped heating medium stretched on the inner wall, and
Examples include rod-shaped heating elements that are thrust into the room.

The injection nozzle 30 injects the hydrogen peroxide vapor vaporized in the vaporization section 20 into the air using compressed air. The diameter of this injection nozzle 30 is adjustable (2 mm to 200 mm).
mm) so that the force of blowing hydrogen peroxide vapor into the air can be adjusted.

Note that if the injection nozzle 30 is long, hydrogen peroxide vapor may be cooled and condensed inside the nozzle.
The outside of the injection nozzle 30 may be coated with a heater (not shown).

In the sterilizer of the present invention configured as described above,
While supplying the heated air flow into the chamber of the vaporization section 20,
Hydrogen peroxide is transferred from the sterilant supply section 10 to the chamber 24 of the vaporization section 20.
When supplied into the room, the hydrogen peroxide comes into contact with the heating means 26 or is heated above its boiling point by the heated air in the room and is completely vaporized. Thereafter, by injecting the completely vaporized hydrogen peroxide vapor into the air from the injection nozzle 30 using compressed air, the hydrogen peroxide vapor is condensed and a fine mist of hydrogen peroxide is generated. By spraying this mist onto the outer surface of the packaging container 38, the sterilant mist flows along the outer surface of the packaging container 38 and is evenly deposited.

In addition, when performing sterilization treatment, it is preferable to rotate the packaging container 38 in the horizontal direction.

Further, in the first embodiment, in order to control the applied amount of the sterilizing agent, the hydrogen peroxide aqueous solution may be supplied when necessary while the compressed air flow is constantly being pumped.

In the above embodiment, the case where there is one injection nozzle 30 has been described, but the number of injection nozzles 30 does not necessarily have to be one, and as shown in FIGS. The injection nozzle 30, 30... of the packaging container 3
Alternatively, as shown in FIG. 5, a ring-shaped supply pipe 31
A plurality of (eight shown) nozzle holes 31a are provided on the lower surface of the .

31a... may be used. By providing a plurality of spray nozzles 30 in this way, the packaging container 3
Hydrogen peroxide can be uniformly deposited without rotating 8.

Next, a comparison test between the sterilization method of the present invention and the conventional sterilization method will be explained.

During the test, as shown in Figure 6, P of 1.5vX
A piece of aluminum foil with 104 spots of Bacillus subtilis spores attached to the outer surface of an ET (polyethylene terephthalate) bottle 38 was placed at 4 locations in the vertical direction (■ to ■) and 4 locations in the circumferential direction (A-D), for a total of 16 locations. pasted on. In this state, the four injection nozzles 30, 30 shown in FIGS. 3 and 4
When we compared the hydrogen peroxide mist sprayed from... and the same hydrogen peroxide spray using four conventional two-fluid nozzles, we found the results shown in Table 1. Obtained.

0 As a sterilization test, after applying hydrogen peroxide and drying it, the piece of aluminum foil with Bacillus subtilis attached was peeled off, immersed in trypto soy broth medium, and cultured at 35°C for one week to test the bacteria. Determine the presence or absence of generation. *-: No generation, good sterilization) +: Occurrence (poor sterilization) In the above test, in the present invention, the amount of hydrogen peroxide attached was 5 μl (microliter) per 25 cd,
There was almost no difference between the parts ■ to ■. Furthermore, since the hydrogen peroxide mist was uniform and fine, it was completely dried by blowing dry air at 50° C. for 20 seconds. As a result of conducting a sterilization test in this manner, all 16 locations of the product of the present invention were free of bacteria (and were sterilized).

On the other hand, in the comparative example, the amount of adhesion was small in the area marked ■■, and in particular, almost no hydrogen peroxide was attached to the area marked ■, whereas a large amount of hydrogen peroxide was attached to the area marked ■. It turned into droplets and could not be dried. Additionally, as a result of the sterilization test, poor sterilization occurred in the areas marked ■■.

◎Second Embodiment FIG. 7 shows a sectional view of a second embodiment of the sterilizer according to the present invention.

The sterilization method in the second embodiment is a case in which the outer periphery of the packaging container is surrounded by a cylindrical body to further improve the adhesion efficiency of the hydrogen peroxide mist. In other words, the cylindrical body 40 is placed around the outer periphery of the packaging container 38 placed on the mounting table 42, and hydrogen peroxide mist is sprayed from above toward the inner surface of the cylindrical body 40. This is the case. In this case, one large injection nozzle 30 is sufficient.

In addition, in the second embodiment, the packaging container 38 and the cylindrical body 40
The gap S between the
mm is preferable, and the material of the cylindrical body 40 may be either metal or plastic as long as it has corrosion resistance against hydrogen peroxide.

In the second embodiment, the cylindrical body 4 is
When hydrogen peroxide mist is injected toward the inner surface of the packaging container 38 in the same manner as in the first embodiment, the hydrogen peroxide mist does not scatter anywhere other than the cylindrical body 40, and the mist density in the space increases. flows along the outer surface and deposits it evenly.

In the second embodiment, when the same cylindrical body 40 is used repeatedly, as the hydrogen peroxide mist repeatedly adheres to the inner surface of the cylindrical body 40, three large drops of liquid are generated, and the hydrogen peroxide mist adheres to the outer surface of the packaging container 38. Since there is a possibility that the efficiency will decrease, as shown in FIG. 8, by wrapping a heater 44 around the outer circumferential surface of the cylindrical body 40 and setting the temperature to a temperature that prevents hydrogen peroxide mist from adhering to the inner surface of the cylindrical body 40. , it can be used repeatedly. Furthermore, the sterilizing effect is improved by increasing the temperature of hydrogen peroxide. In this case, the cylindrical body 40 is made of a metal with good thermal conductivity, such as stainless steel.

Next, a comparison test between the sterilization method of the second example and a comparative example will be explained.

During the test, as shown in Figure 8, 1.5i! A stainless steel cylindrical body 40 having a diameter of 140 mm was surrounded around the outer periphery of a PET (polyethylene terephthalate) bottle 38, and a ribbon heater 44 was wrapped around the outer circumferential surface of the cylindrical body 40 to maintain an inner temperature of 100°C. Moreover, one injection nozzle 30 with a diameter of 36 mm was used. and,
As in the case of the first embodiment shown in FIG.
Two types of aluminum foil pieces (10'/spot, 105/spot) were used in which aluminum foil pieces with different types were attached to 44 areas vertically (■ to ■) and 4 areas circumferentially (A-D). . In this state, the hydrogen peroxide mist was blown out from one injection nozzle 30 toward the inner surface of the cylindrical body 40 as shown in FIG. 8, and the first embodiment in which the cylindrical body 40 was removed. When comparing the test with hydrogen peroxide injected under the same conditions as the above test, it was found that when Bacillus subtilis spores were set at 104/spot, all parts (■ to ■
, A-D), no bacteria were generated, but when Bacillus subtilis spores were set at 105/spot, the results shown in Table 2 were obtained.

In addition, in the test, the adhesion was not able to be measured with the heater 44 installed because the drying effect was performed at the same time as the adhesion of the hydrogen peroxide mist, but the adhesion with the heater 44 not installed was similar to the above-mentioned method. 25cn similar to one example
The volume was 5 μl (microliter) per f.

Table *When Bacillus subtilis spores are 105/spot, the comparative example is the case without the cylindrical body of the first example - no outbreak, good sterilization) 10: outbreak (poor sterilization) In addition, the above experimental example In the above, the case where hydrogen peroxide was used as a sterilizing agent was explained, but the same effect could be obtained by using an aqueous peracetic acid solution or a mixed aqueous solution of peracetic acid and hydrogen peroxide instead of hydrogen peroxide.

Moreover, it is more effective to use the sterilizer shown in FIG. 9. That is, as the sterilizing agent supply section 10, one similar to the above-mentioned two-fluid spray is used. However, if the nozzle 10a is attached to its body, e.g.
They are connected via an extension pipe 50 with a length of 0.5 an.

This is because heat from the vaporization tube 51 as the vaporization section 20 is transmitted to the two-fluid spray main body via the aluminum plug 52 that closes the upper end of the vaporization tube 51 and the nozzle 10a.
This is to prevent the two-fluid spray main body from being heated. The vaporization pipe 51 has an outer cylinder 5 made of asbestos ribbon.
3, an inner cylinder 54 having a length of, for example, 35 mm and made of a sanitary pipe forming the inner wall of the vaporizing tube 51, and a ribbon heater 55 provided between the outer cylinder 53 and the inner cylinder 54. A nozzle 56 having a length of, for example, 12 ann is connected to the lower end of the vaporizing pipe 51, through which hydrogen peroxide vapor vaporized within the vaporizing pipe 51 is injected.

In order to average out the vaporization, it is important not to create a place with a low temperature or a place where the temperature easily drops in the vaporization tube 51. For this purpose, a ribbon heater 55 is provided over the entire length of the vaporization tube 51. ing. In addition, the diameter of the vaporizer tube 51 is set to be sufficiently large so that pressure is not applied inside the vaporizer tube 51 when hydrogen peroxide is sprayed from the two-fluid spray, and the peroxide vaporized in the vaporizer tube 51 may be prevented. The vaporizing tube 51 extends vertically so that hydrogen vapor can be easily removed, and the inner surface of the vaporizing tube is formed to be smooth without any undulations or bends. Furthermore, if the vaporizing tube is formed to have an appropriate diameter and a straight body shape, insufficient vaporization of hydrogen peroxide will not occur.

Note that this device uses a spray air pressure of 5 kg/ca, for example.
r. Hydrogen peroxide supply method is best to use natural suction, sanitary pipe temperature and nozzle temperature at 300°C, and stand vertically.

8 [Effects of the Invention] As explained above, according to the method and apparatus for sterilizing packaging containers of the present invention, since the method and apparatus for sterilizing packaging containers are configured as described above,
The following effects can be obtained.

1) According to the sterilization method according to claim 1, the generated sterilant mist is sprayed from a direction other than perpendicular to the outer surface of the packaging container and is attached along the outer surface of the packaging container, so that the sterilization method can be easily and efficiently carried out. The sterilizing agent can be easily and evenly applied to the outer surface of the packaging container.

2) According to the sterilization method according to claim 2, in order to inject the generated sterilant mist toward the inner surface of the cylindrical body surrounding the outer periphery of the packaging container and to make it adhere along the outer surface of the packaging container, In addition to the above 1), since the density of the sterilant mist in the space increases, it is possible to further improve the adhesion efficiency.

3) According to the sterilization method according to claim 3, since it is possible to prevent condensation of the sterilant mist by increasing the temperature of the inner surface of the cylindrical body, it is possible to repeatedly use the container and to prevent the condensation of the sterilant mist from forming on the outer surface of the packaging container. As the temperature of the attached sterilizing agent 9 increases, the sterilizing effect can be further improved.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a first embodiment of a sterilizer according to the sterilization method of the present invention, FIG. 2 is a sectional view of a main part of the first embodiment, and FIG. 3 is a diagram showing another aspect of the first embodiment. FIG. 4 is a plan view of FIG. 3, FIG. 5 is a perspective view showing another aspect of the first embodiment, and FIG. 6 is a side view of a packaging container used for sterilization tests. FIG. 7 is a sectional view of a second embodiment of the sterilizer according to the sterilization method of the present invention, FIG. 8 is a sectional view showing another aspect of the second embodiment, and FIG. 9 is a sectional view of the sterilizer according to the present invention. Another example diagram, FIG. 10, is a schematic explanatory diagram showing a conventional sterilization method, and FIG. 11 is a graph showing the relationship between the part of the packaging container and the amount of sterilizing agent adhered in the conventional sterilization method. 10... Sterilizing agent supply unit, 12... Hydrogen peroxide aqueous solution (liquid sterilizing agent), 20...
- Vaporization part, 0 6... Heating means, 0... Injection nozzle, 1... Ring-shaped supply pipe, 2... Air flow generation part, 4... Pressure feeding pipe, 0... Cylinder body, 4... heater

Claims (1)

[Claims] 1. After vaporizing the liquid sterilant, it is condensed in the air to generate a fine sterilant mist, and the generated sterilant mist is directed in a direction other than perpendicular to the outer surface of the packaging container. A method for sterilizing a packaging container, characterized in that the sterilization is sprayed from above and applied along the outer surface of the packaging container. 2. After vaporizing the liquid sterilant, it is condensed in the air to generate a fine sterilant mist, and the generated sterilant mist is sprayed towards the inner surface of the cylindrical body surrounding the outer periphery of the packaging container. Also, a method for sterilizing a packaging container, characterized in that the sterilization is applied along the outer surface of the packaging container. 3. The method of sterilizing a packaging container according to claim 2, wherein the temperature of the inner surface of the cylindrical body is increased to prevent the sterilant mist from condensing on the inner surface of the cylindrical body.