JPS6350252B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention belongs to the field of containers for foods, etc., and specifically relates to a method for aseptically packaging empty containers for filling food.

(Prior Art) Conventionally, it has been thought that it is impossible to heat-treat empty plastic containers until they are sterilized before being filled with food because this would cause deformation and alteration of the container.

(Problems to be Solved by the Invention) Empty containers for food filling made of plastic have relatively thin container bodies, so there is a risk of deformation and deterioration when subjected to heat treatment, and chemical substances may cause Even if sterilization was possible through treatment, there was a risk of chemical substances remaining.

(Means for Solving the Problems) The present invention was devised to solve the above-mentioned problems, and its purpose is to make empty plastic containers for food filling extremely inexpensive. When food is easily sterilized and packaged, when food is filled into empty containers sterilized by the method of the present invention, there is no risk of deterioration of the food due to bacteria adhering to the container; There is no longer any fear of harming hygiene.

That is, the present invention stores an empty plastic container for food filling in a plastic bag having a through hole, and heats it at a temperature between 70°C and 220°C for a period of at least 0.2 seconds and up to 5 hours. The container is sterilized by dry heat treatment within the area indicated by the shaded area in the figure, and after the sterilization treatment, it is left to cool in an aseptic condition, and then the container is sealed and packaged in a sterile plastic film in an aseptic condition to achieve its purpose. I tried to reach it.

By filling the empty containers obtained by the method of the present invention with sterile food and sealing the containers, changes in taste can occur in a hygienic and stable manner over a long period of time without heat sterilization of the food after filling the containers. Now it is possible to save without any problems.

The reason why the heating time and temperature are limited as described above in the present invention is as follows. In other words, to sterilize heat-sensitive bacteria, it is necessary to heat the bacteria to 70°C or higher, and they cannot be killed at temperatures lower than 70°C. Also, all bacteria attached to the container will be killed at 220°C, so there is no need for temperatures higher than 220°C.
The heating time varies depending on the selected sterilization temperature, and is appropriately determined within the shaded area in FIG. 1 depending on the heat resistance of the container and the degree of bacterial adhesion (degree of contamination).

(Example) First, a plastic container for filling food that can be used in the present invention will be described. Examples of plastic materials include polypropylene, polystyrene, high-density and low-density polyethylene, heat-resistant polyvinyl chloride, polyester, and polycarbonate. , these alone or in combination with appropriate fillers such as talc and calcium carbonate,
It can be used by blending with plasticizers, stabilizers, pigments, etc.

Among these molding materials, any material that can withstand dry heating within the temperature range of 70° C. to 220° C. for a time of 0.2 seconds or more and less than 5 hours within the range shown by the sloped portion in FIG. 1 may be used.

The plastic container may be molded from the plastic by injection molding, blow molding, vacuum molding, pressure molding, or any other method. The present invention can also be applied to containers formed from plastic films, laminated with films or paper, or coated materials.

The shape of the container can be selected as appropriate depending on the contents of the intended filling food, but square, round,
Tray shapes, bottle shapes, etc. are generally used, and the wall thickness is approximately 0.3 to 3 mm.

These containers may be of any type as long as they are not substantially deformed or altered by heating within the above-mentioned temperature range.

Next, a relatively heat-resistant plastic bag for accommodating a large number of plastic containers obtained as described above will be described.

The plastic film used for this bag is usually polyethylene, which has a thickness of about 0.1 to 1 mm.
Made of plastic film such as polyvinyl chloride, polypropylene, polyester, and low-pollution sheet, this bag has 2000 to 4000 through holes with an inner diameter of 1 to 5 mm.
pcs/m ² (one pcs/m 2 for every 2 to 2.5 cm of the surface of the bag).

Note that the circular through hole may be replaced with a slit-like through hole, but in that case, the holes may be opened at the same area ratio.

When using bags with these perforations, their roles are to improve work efficiency by collecting empty containers all at once, and to enhance the heat sterilization effect.
This is to eliminate the odor generated by heating from plastic containers and bags during heat sterilization, and to prevent contact with other objects as much as possible during cooling.

A large number of empty plastic containers for food filling are placed in a plastic bag having through-holes as described above, and then transferred to a heating device through a clean room.

As the heating device, a commercially available large-sized dryer (heat treatment device) can be used.

For example, a heating device has internal dimensions of its chamber,
It is 150cm (180cm) wide, 150cm high, and 150cm deep, has an electric heating capacity of 15.5kw to 21kw, a temperature range of 40 to 200℃, automatic temperature control, and a circulation device.

A movable shelf cart is prepared according to the internal dimensions of the heating device room, and at the time of starting processing and cooling, the collapsing cart is pulled out to the outside of the device room to store or take out empty containers.

An empty plastic container for food filling is stored in this heating device, and the conditions within the range shown in the shaded area in Figure 1 are met.
For example, it is sterilized by heating at 100°C to 160°C for 30 minutes to 5 hours.

It has been found that this operation kills mold, yeast, bacteria, etc. adhering to the container, making it sterile from the viewpoint of food hygiene.

In the present invention, the heating means performs dry heating in normal air without special humidification. This is because it is desirable that no water droplets adhere to the container during cooling after heating.

After the heating operation in the heating device is completed, the treated plastic container is transferred to a clean room that is directly connected to the heating device in an aseptic manner, and then cooled by being left in a sterile state.

This usually takes about 30 minutes to 1 hour.

Clean rooms that can be used in the present invention include:
It is a sterile room that allows people to enter and work and is equipped with equipment that allows operations to be performed under sterile conditions.

This clean room is directly connected to the heating device room, and has a structure in which a number of plastic containers containing contents are connected to each other so that they can be moved. After the heat sterilization process has been completed, the plastic container inside the heating device is moved to a clean room and left to cool down to room temperature.

The plastic bag containing the cooled plastic containers and having through holes is further packaged using a previously sterilized plastic film bag. This plastic bag can usually be made of a film made of polyethylene, polypropylene, polyvinyritene, polyvinyl chloride, or the like.

A large number of such sterilized plastic containers for food filling are collected and packaged in an aseptic condition, and then the food can be stored for a long time by filling and sealing the container in an aseptic condition. .

Examples of foods that can be filled into empty containers that have been sterilized by the method of the present invention include margarine, cheese, butter, pudding, jelly, jam, marmalade, liver paste, and meat sauce.

By using the method of the present invention, the packaged containers filled with food under aseptic conditions do not require further heating, and the food can be stored for a long period of time without the addition of chemicals that may be harmful to hygiene. It has the characteristic that it can be preserved without reducing its taste.

Hereinafter, an apparatus for carrying out the method of the present invention will be explained based on the drawings.

FIG. 1 is a diagram showing the relationship between temperature and time required for dry heat treatment in the present invention, where A is the point where the heating is performed at a temperature of 130°C for 0.2 seconds, B is the point where the heating is performed for 0.2 seconds at a temperature of 220°C. C is the point of heating at a temperature of 160℃ for 5 hours, D is the point of heating at a temperature of 70℃ for 5 hours,
The present invention is based on ABCD.
Dry heat treatment is performed within the sloped area surrounded by dots.

Figures 2 and 3 show a device for sterilizing empty containers for food filling, which combines two heating devices, a clean room, and an air shower room. The figures each show a front view.

In the figure, 1 is a clean room, and heating device rooms 2 and 3 are located on both sides of the clean room.

Reference numeral 4 denotes a shelf truck for storing containers to be processed, and the illustration shows this shelf truck 4 located inside the clean room and the heating device room 2.

Air filter units 6 and 7 are attached to the ceiling of the clean room 1, and an air shower room 5 is located on one side of the front of the clean room 1.

FIG. 4 shows a state in which a plurality of empty containers to be processed are housed in a plastic bag with a through hole, 8 is a plastic bag with a through hole, 9 is a container to be processed, and 10 is a plastic bag with a through hole in the plastic bag 8. show.

The product in this state is placed on the shelf carts 4 and 4 shown in FIGS. 2 and 3 and subjected to heat treatment.

Hereinafter, an example of an actual sterilization operation means will be explained.

First, in the clean room 1 shown in Figures 2 and 3, the filter units 6 and 7 are operated to maintain the dust concentration below class 10,000 in accordance with the National Aeronautics and Space Administration NASA standards, and the container 9 to be treated is
For example, 50
Prepare multiple individual items.

Next, a worker enters the clean room 1 wearing dust-free clothes from the air shower room 5, and a plastic bag 8 with a through hole is filled with a container 9 to be processed.
are carried into the clean room 1 and arranged on the shelf cart 4.

Next, the shelf cart 4 is pushed into the heating device chambers 2 and 3, and the doors are closed to start sterilization.

Prior to sterilization treatment, preheating treatment is performed as necessary.

For example, the preheating method is 50℃ for 30 minutes, 70℃ for 30 minutes,
Hold for a minute. After this, as a dry heat treatment according to the present invention, after sterilization by holding at 110°C for 3 hours, it was immediately taken out and left to cool for 30 minutes, and then sealed and packaged again with a sterile bag placed over the bag 8 having a through hole as shown in Fig. 4. , taken out of the clean room 1, stored in a container such as a carton, and transported or stored.

The use of two heating devices, as shown in FIGS. 2 and 3, was designed so that the main body and lid of the container to be treated can be treated at the same time.

Regarding the method of the present invention, the effectiveness of the method was confirmed by smearing mold bacteria on a container and then sterilizing the container.The results will be described below.

A bacterial smear concentration of 4 species of Aspergillus in the container to be treated is 10 ² 10 ⁴ 2
Smear each type of sample at 110℃ for 5 samples of each combination.
2 hours, 110°C 3 hours, 110°C 4 hours, 120°C 2 hours, 130°C 2 hours, and treatment times of Penicillium genus, Aspergillus genus 2 species, Cladosporium genus Approximately 15 mixed bacteria were smeared per container and 200 samples were treated at 110°C for 3 hours. In the bacterial test, which was cultured on potato dextrose agar medium at 25°C for 5 days, there were 0 positive (+) results in all cases. The effectiveness of the treatment method has been confirmed.

(Effect of the invention) The present invention provides 70 plastic empty containers for food filling.
Sterilize by dry heat treatment within the shaded area in Figure 1 at a temperature between ℃ and 220℃ for a period of 0.2 seconds or more and within 5 hours, and after the sterilization treatment, let it cool in an aseptic condition, and then Since the container is sealed and packaged in a sterile plastic film in an aseptic condition, the empty container can be sterilized very easily without being deformed or deteriorated. Containers can be provided at low cost.

Moreover, since these empty containers are stored all at once in a plastic bag with perforations, the sterilization, cooling, and packaging processes are easy and extremely efficient, and there is no need to waste other items during the post-sterilization process. There is no touching, and the odor generated during heat sterilization is easily discharged through the holes.

Since the heating means of the present invention is dry heating in normal air without special humidification, water droplets do not adhere to the empty container after cooling, and sterilization using chemical substances is not required. Therefore, there is no risk of chemical substances remaining.

Therefore, since the container heat-treated by the method of the present invention does not require any chemical sterilization, the food filled in an aseptic state can be stored for a long period of time without deteriorating its taste.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the relationship between necessary temperature and time when performing dry heat treatment in the method of the present invention, Figs. 2 and 3 are a plan view and a front view of the apparatus used in the method of the present invention, and Fig. 4 FIG. 1 is a perspective view of a container to be sterilized by the method of the present invention. 1... Clean room, 2, 3... Heating device room, 4... Shelf truck, 5... Air shower room, 6,
7... Air filter unit, 8... Perforated plastic bag, 9... Container to be processed, 10...
Hole.

Claims (1)

[Claims] 1. An empty plastic container for food filling is placed in a plastic bag with a through hole, and the container is heated to 70°C.
The container is sterilized by dry heat treatment at a temperature between 0.2 seconds and 5 hours at a temperature between 220°C and 220°C, and after the sterilization process, it is allowed to cool under aseptic conditions, and then the container is sealed in a sterile plastic container under aseptic conditions. A method for aseptically packaging empty containers for food filling, characterized by sealing the packaging with a film. 2. The aseptic packaging method for empty containers for food filling according to claim 1, wherein preheating treatment is performed in stages prior to dry heating treatment. 3. The aseptic packaging method for empty containers for food filling according to claim 1 or 2, wherein the heat sterilization treatment is performed in a heating chamber, and the cooling is performed in a clean room directly connected to the heating chamber.