JPH0536293B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a gas replacement device for replacing active gas with inert gas in the head space of a molded container filled with contents such as food.

BACKGROUND TECHNOLOGY When filling and sealing a container, a head space is sometimes provided to ensure the stability of the seal and to prevent the contents from spilling when the container is opened. As a result, if the contents are food, etc., the oxygen in the head space will deteriorate the food, so to prevent this, the active gas such as air in the head space is replaced with an inert gas and sealed, which is called gas replacement. Packaging is being done.

The inert gas used in the above gas replacement packaging is
Usually nitrogen gas or carbon dioxide gas is used, and in rare cases a mixture of both gases is used. By that,
It is effective in preventing bacteriostasis of aerobic bacteria in packaged foods, preventing rancidity, discoloration and fading, and preventing the growth of mold.

In conventional gas displacement packaging, a packaging container filled with contents is inserted into a chamber, the chamber is evacuated, and the active gas inside the packaging container is degassed.
This is then done by blowing an inert gas into the chamber to fill the head space of the container with the inert gas and sealing the opening of the container within the chamber.

In addition, for containers with narrow openings such as bottles, inert gas can be sprayed directly onto the opening of the container during conveyance without vacuum degassing within the chamber to deactivate the active gas in the container head space. Replacement with gas has also been carried out (for example, Japanese Patent Publication No. 15432/1983).

Problems to be solved by the invention The above-mentioned chamber that performs gas replacement is
Since the inside of the chamber is first evacuated and then inert gas is blown into it, it takes time and reduces work efficiency. Furthermore, since the chamber is filled with blown active gas each time, a large amount of inert gas is required, resulting in a large loss of inert gas. Furthermore, when the conventional method is applied to a model filling and sealing machine for molded containers that automatically performs the process of filling the molded containers with contents and sealing the lid, as the conveyor that conveys the molded containers advances, Since the chamber must be opened and closed, and the conveyor portion on which the container is placed must be positioned within the chamber to ensure a tight seal when the chamber is closed, there is a disadvantage that the apparatus is complicated and expensive.

In addition, in the method of performing gas replacement by directly spraying inert gas without vacuum degassing, the space between the nozzle mouth and the container opening is open to the atmosphere, so air flows into the container mouth from the surroundings. It is difficult to increase the gas replacement rate beyond a certain level, and this method can only
The replacement rate can only be increased to about 90%. Therefore, in the invention described in Japanese Patent Publication No. 50-15432, cold nitrogen gas generated from liquid nitrogen is used as the inert gas, and is directly blown into the container at -150〓 to -250〓 (-101℃ to - An external flow with a higher temperature than the central flow is blown out to the outside of the container around a central flow at a very constant temperature of 157℃) to form a nitrogen gas mist or gas layer around the container, which allows air to flow in from the outside. I try to prevent this. Therefore, this device requires a composite nozzle to generate a central flow and an external flow, and also has to take insulation measures to generate low-temperature gas, making the device very complicated and large in size. . Furthermore, since the device is exclusively for bottles, it is difficult to apply the device to an inert gas replacement device for molded containers that are held and transported on a bucket conveyor. Also, this method
The density of the nitrogen gas is an important factor, and depending on the temperature of the nitrogen gas, the substitution rate becomes extremely poor, and the residual oxygen reaches as much as 3% near room temperature.
This residual oxygen of 3% is converted to a substitution rate of 85.6%.
This has a significant negative impact on the quality of highly oxygen-sensitive foods.

In general, cooked foods such as white sauces are susceptible to browning due to oxygen, so it is preferable that the residual oxygen concentration be within 1% (replacement rate of 95% or more), and foods such as sweet corn should have a residual oxygen concentration of 2% or less. (replacement rate of 90% or more) is desirable. however,
As mentioned above, an inert gas replacement device for molded containers that can achieve a replacement rate of 90% or more with a simple device at room temperature has not yet been provided.

Therefore, the present invention provides an apparatus that directly performs inert gas replacement without vacuum degassing of a molded container. A simple molded container that can increase the filling rate to 90% or more, preferably 95% or more, can be easily applied to a molded container filling and sealing machine, has a simple device and can be manufactured at low cost, and has low running costs. The technical challenge is to obtain a gas replacement device for this purpose.

Means for Solving the Problems The gas replacement device for molded containers of the present invention solves the above problems by deactivating the active gas in the molded containers that are filled with contents and transported by a conveyor with the top open. A device for replacing gas with gas, which has an inert gas supply port, a bottom opening with an area that can cover at least one opening of a molded container, and a plurality of holes in the bottom opening. A technical means is adopted, characterized in that a chamber body covering a nozzle plate having a chamber body is disposed on a side plate disposed close to above the conveyor along both sides of the conveyor in the moving direction. This has been resolved.

Effect By supplying inert gas to the chamber body from the inert gas supply port, positive pressure is created inside the chamber body, and the inert gas flows down in a shower shape from the many holes formed in the nozzle plate, and is transported by the conveyor. and is sprayed into the head space of the molded container located below it. On the other hand, the lower space of the nozzle plate is isolated on both sides by side plates, which prevents external air from entering from the left and right sides.
The inert gas flowing down from the nozzle plate is blown onto the head space of the molded container without involving outside air, and the active gas (air) inside the molded container is efficiently expelled and replaced with inert gas at a high substitution rate. Thereafter, the opening of the container is covered with the lidding film and transported to a sealer section, where it is sealed.

According to the gas replacement device of the present invention, the inert gas replacement rate can be increased to 95 to 99% when the inert gas (nitrogen gas) temperature is around 25 to 30°C (room temperature), and it is possible to increase the inert gas replacement rate to 95 to 99%. Can be easily installed on container-like filling and sealing machines. and,
The inert gas flows down from directly above the container opening in a shower-like manner, and since both side plates are provided, the nozzle plate can be separated from the container, and even if the contents rise above the container, the nozzle plate can be removed. Gas can be replaced efficiently without staining the plate.

Note that, for example, when inert gas is simply sprayed vertically from a single hole instead of spraying inert gas in a shower-like manner as in the present invention, the liquid may boil over for watery, low-viscosity foods. If the injection pressure of the inert gas is lowered to prevent boiling over, the replacement rate will be lowered. Furthermore, if the inert gas is blown from the side instead of directly above in a shower-like manner, a high replacement rate cannot be achieved because outside air is drawn in along with the flow of the inert gas.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

The container gas replacement device according to this embodiment is installed between a filling device and a heat sealing device in a well-known filling and sealing device that fills a molded container with contents and heat-seals the lid. The molded container 1 is molded from plastic, a laminated film of metal foil and plastic film, paper material, etc.
Has gas barrier properties. The molded container 1 is filled with contents by a filling device (not shown), and is transported to a lower part of a gas replacement device to be described below while being fitted and supported by a bucket 3 of a bucket conveyor 2.

The gas replacement device 5 is composed of a chamber body 7 covered with a nozzle plate 6 whose lower surface is flat, and an upper opening 8 of the chamber body 7 communicates with an inert gas supply source such as nitrogen gas via a flow rate control valve. Then, an inert gas is introduced into the chamber. The nozzle plate 6 is made of a synthetic resin plate such as vinyl chloride or a metal plate, and is provided with a large number of round holes 9. The round hole 9 is provided vertically, but the round hole located at the front end of the nozzle plate is provided with an inclination toward the conveyor and the direction of movement, so that the container does not close until the opening of the container is covered with the lidding film. The number of round holes 9 that allow active gas to flow is 5 to 5.
A range of 20 pieces/ ^100cm2 is appropriate, and the hole diameter is 1
~5mm range is good. In addition, the size of the lid nozzle plate should be large enough to cover the top surface of one bucket, but in order to further increase the replacement rate, it should be large enough to cover the top surface of 1.5 connected buckets. is desirable. The nozzle plate configured in this manner is fixed to the lower opening of the chamber by appropriate means. If you prepare multiple nozzle plates with different numbers and sizes of round holes in advance and replace them according to the inert gas replacement conditions,
More appropriate inert gas replacement filling and sealing is possible depending on the container to be replaced.

As shown in FIG. 2, the chamber body 7 is arranged above the side plates 10 provided along the conveyor in the range A-B in FIG. ing. As a result, the nozzle plate 6, the side plate 10, the molded container 1, and the bucket 3 constitute a chamber, and the inert gas flowing down from the nozzle plate 6 creates a positive pressure inside the chamber, thereby preventing the inflow of outside air.
In addition, a clearance can be provided between the nozzle plate 6 and the top surface of the molded container, so even if the contents swell up or the liquid level is fluctuating during transportation due to low viscosity, the nozzle plate 6 is not soiled and the seal portion of the container is not soiled, so there is no possibility of seal failure. In order to achieve the above effects, the distance between the nozzle plate 6 and the molded container 1 must be 2
It is desirable to set the height so that it is within the range of ~10 mm.

Further, the chamber body 7 is arranged so that its downstream edge is close to the pressing roller 14 of the lidding film 1, and as soon as the molded container passes the lower part of the chamber body 7, the upper part thereof is pressed against the lidding film 12. It is covered with a twist to prevent air from entering between them.

The lidding film 12 is rewound from a supply roll (not shown), passes through the upper part of the gas exchange device 5, is deflected by a pressing roller 14 located at the tip of the chamber body 7, and is pressed against the upper part by a pressing roller 14.
6 prevents it from rising and covers the opening of the molded container, and the sealer device 1
5. The sealer device 15 heat-seals the lidding film 12 to the flange portion of the opening of the molded container, completing the gas replacement filling and sealing.

What is shown in FIG. 4 is an embodiment of a gas exchange device applied when the bucket conveyor has two buckets and conveys molded containers in two rows, and has two chambers 20 in the width direction. , 21. The chamber body 22 is configured to form . The other structure of the apparatus of this embodiment is the same as that of the apparatus of the above embodiment.

The inert gas replacement device is constructed as described above, and by showering nitrogen gas from the nozzle plate into the opening of the container at a rate of 2 to 10 minutes, the active gas in the head space can be removed by 95 to 99%. It was possible to replace the gas with nitrogen gas at a high replacement rate before and after.

Effects The gas replacement device of the present invention has the following special effects.

The inert gas flows uniformly in a shower-like manner from directly above the container opening, and the side plates on both sides prevent air from entering from outside, achieving a replacement rate of 95%.
The active gas in the container head space can be replaced with an inert gas at the above high replacement rate.

Since the inert gas flows down from just above the opening of the container in a shower-like manner, even watery, low-viscosity foods can be replaced at a high replacement rate without boiling over. Moreover, since both side plates are provided and the nozzle plate is separated from the container, even if the contents bulge out of the container or the contents are low viscosity liquids whose liquid level fluctuates during transportation, the container or plate can be easily removed. This prevents seal failure.

Furthermore, the structure is simple, it can be easily attached to a conventional filling and sealing machine for plastic molded containers, the equipment cost is low, and the running cost is also low.

[Brief explanation of the drawing]

The drawings show an embodiment of the gas replacement device of the present invention, and FIG. 1 is a side sectional view applied to a horizontal filling and sealing machine for molded containers, FIG. 2 is a sectional view of FIG. 1, and FIG.
FIG. 3 is a sectional view of FIG. 1, and FIG. 4 is a plan view of another embodiment. 1: Forming container, 2: Bucket conveyor, 3: Bucket, 5: Gas replacement device, 6: Nozzle plate, 7: Chamber body, 9: Round hole, 10: Side plate, 12: Lid film, 14: Presser Laura, 1
5: Sealer device, 16: Presser guide, 20,2
1: Chamber, 22: Chamber body.

Claims (1)

[Claims] 1 A device for replacing the active gas in a molded container filled with contents and transported by a conveyor with the top open, with an inert gas, which has an inert gas supply port and has at least one bottom surface. A chamber body, which has an opening having an area that can cover the opening of each molded container, and whose bottom opening is covered with a nozzle plate having a large number of holes, is installed along both sides of the conveyor in the moving direction. A gas replacement device for a container, characterized in that the device is disposed on a side plate disposed close to the top of a conveyor.