JPH0541489B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an inert gas filling and packaging method for filling and sealing a container such as a plastic cup containing food or the like with an inert gas.

BACKGROUND TECHNOLOGY In recent years, as shown in FIG. 8, a cup-shaped container a is filled with a content b such as food rich in solids, and a sealing sheet (lid) c is used to seal the top opening of the container a. When heat sealing the opening periphery of the container a and the sealing sheet c, fill the head space e in the container a with an inert gas such as nitrogen gas to replace the air with the inert gas. things are being done.

In this case, if the residual rate of air in the head space e is high, the content b will be easily oxidized when it is retort sterilized, and it will also cause aerobic bacteria such as mold to propagate. It is preferable to increase the gas replacement rate as much as possible, and specifically, it is desired that the amount of residual oxygen is 1% or less.

In this way, the container is filled with inert gas,
Conventionally, the method of packaging containers by sealing them with a sealing sheet is to place one or more containers filled with contents in a chamber, create a vacuum inside the chamber, and then fill the chamber with an inert gas. A method is adopted in which a sealing sheet is heat-sealed to the opening of the container within the chamber with the chamber filled with inert gas.

In addition, if the packaging is tube-shaped, a simple method is used to fill the packaging with inert gas by continuously injecting inert gas into the tube, sealing it, and cutting it. has been done.

Problems to be Solved by the Invention However, the former method described above requires large-scale mechanical equipment and is therefore costly. In addition, since heat sealing is performed by impulse sealing, there are restrictions on the shape of containers that can be used. For example, containers with square openings can be used successfully, but containers with oval openings There are problems in that the sealing sheet (lid) cannot be heat-sealed well, and there is a limit to the sealing pressure during heat-sealing, making it impossible to apply pressure above a certain level. Furthermore, this method requires a large amount of inert gas, which also has the disadvantage of increasing costs.

In addition, the latter method involves a lot of loss of inert gas,
There is a problem in terms of economic efficiency. Furthermore, the substitution rate is lower than in the above-mentioned method, and it is practically impossible to reduce the amount of residual oxygen to 1% or less. For this reason, there are drawbacks such as the possibility that the contents may be oxidized during retort sterilization and that aerobic bacteria such as mold may grow during long-term storage.

The present invention has been made in view of the above circumstances, and includes:
With simple equipment, even containers with complex shapes such as oval shapes can be filled with inert gas and packaged at low cost, and inert gas loss can be reduced as much as possible. Another object of the present invention is to provide an inert gas filling packaging method that can achieve a high replacement rate with a residual oxygen content of 1% or less, which can reliably prevent oxidation of contents and the propagation of aerobic bacteria.

Means for Solving the Problems In order to achieve the above object, the inert gas filling packaging method of the present invention covers the opening of the container containing the contents with a sealing sheet, and the sealing sheet is inserted into a notch-like shape. Nozzle insertion space = Forming groove and air leak space = Forming a nozzle insertion space and a smaller air leak space on the periphery of the container opening using a heat sealing plate having a forming groove. At the same time, the nozzle tip is inserted into the container from the nozzle insertion gap and an inert gas is spouted into the container from the nozzle tip, and the inert gas is introduced into the container. The inside of the container is filled with inert gas by expelling the air inside the container to the outside of the container through the air leak gap, and then the nozzle is pulled out of the container, and a sealing sheet is placed all over the periphery of the opening of the container. The nozzle insertion gap and the air leak gap are closed by heat sealing to seal the container.

Function: In the inert gas filling packaging method of the present invention, a sealing sheet is temporarily heat-sealed around the opening of a container containing contents so that a nozzle insertion gap and an air leak gap are formed. By putting inert gas inside, the loss of inert gas is minimized, and an inert gas jet nozzle is inserted from the nozzle insertion gap and inert gas is spouted from there to prevent the air leak. By smoothly expelling the air inside the container through the gap, the inert gas replacement rate and replacement speed are increased.

In this case, in the method of the present invention, the above-mentioned temporary heat sealing and inert gas filling using the nozzle are performed at the same time, so that the inert gas introduced into the container expands thermally due to the heating during the temporary heat sealing. By doing so, and by making the air leak gap for discharging gas from the inside of the container smaller than the nozzle insertion gap, the inside of the container is pressurized. Air will not flow into the container until the final heat seal is performed to close the insertion gap and the air leak gap. As a result, an extremely high substitution rate with a residual oxygen content of 1% or less is finally achieved.

In addition, temporary heat sealing and inert gas filling are performed at the same time, and the nozzle is immediately pulled out from the nozzle insertion gap after temporary heat sealing, so the heating during temporary heat sealing causes the nozzle insertion gap of the sealing sheet to be pulled out. The heat-sealed portion and the air leak gap become taut, and the final heat-sealing process to close the gap can be neatly heat-sealed without wrinkles or the like.

Furthermore, in the inert gas filling packaging method of the present invention, there is no need to employ impulse sealing as a heat sealing method, and therefore containers of arbitrary shapes such as ellipses can be used, and containers such as vacuum chambers can be used. There is no need for large-scale equipment.

As described above, according to the inert gas filling and packaging method of the present invention, even containers with complicated shapes such as oval shapes can be filled with inert gas and packaged at low cost using relatively simple equipment. A high replacement rate with a residual oxygen content of 1% or less, which can reduce the loss of inert gas as much as possible, and reliably prevent the oxidation of the contents and the propagation of trophophilic bacteria. can be achieved.

Embodiments of the present invention will be described below with reference to FIGS. 1 to 5.

Embodiment FIGS. 1 and 2 show an example of an inert gas filling packaging device used to carry out the method of the present invention.
Reference numeral 1 in the figure is a base, and this base 1 is equipped with a plurality of container receiving buckets 2 that automatically move sequentially in the direction of the arrow in the figure by the operation of cylinders, etc., and inside these buckets 2. A ring-shaped flange 3b is protruded from the outer periphery of the upper opening of the square cup-shaped container main body 3a, and a plastic container 3 containing contents 4 such as food rich in solids is placed inside. has been done.

Further, 5 is a film roll 6 to a take-up roll 7.
The sealing sheet 5 is wound up at a winding speed that is synchronized with the traveling speed of the bucket 2, and the sealing sheet 5 is placed so as to cover the opening of the container 3 by a film guide roller 8.

Furthermore, 9 is a sheet 5 that covers the opening of the container 3.
A first heat sealing plate (temporary heat sealing plate) 10 disposed at a predetermined position above is disposed on the side of the first heat sealing plate 9 in front of the bucket 2 of the first heat sealing plate 9 in the traveling direction. The second heat sealing plate (main heat sealing plate) 11 is a trimming device disposed on the side of the second heat sealing plate in front of the bucket 2 in the traveling direction of the second heat sealing plate 10.

Further, the tip 12 is arranged so that its tip reaches the container position B facing the first heat sealing plate 9 from the rear in the traveling direction of the bucket 2, and is inserted and projected from the rear into the upper end of the container 3 existing at this position B. This is an inert gas filled nozzle. As shown in FIG. 3, this nozzle 12 is formed into a flat shape, and a number of ejection holes 13 are bored in the side wall and lower wall of the tip end thereof. Note that the ejection holes 13 are formed to have a smaller diameter toward the tip end, so that the ejected inert gas flows forward.

Furthermore, 14 is a balance guide that removes inert gas when it enters the container 3 in an excessive amount.

Here, in this apparatus, the first heat sealing board (temporary heat sealing board) 9 has a frame-shaped contact part 9a corresponding to the ring-shaped flange part 3b of the container 3,
As shown in FIG. 4, a groove 15 for nozzle insertion is formed in this abutting portion 9a at the rear in the direction of movement of the container 3, and a predetermined number of grooves 15 are formed in the front facing the groove 15. (One air leak gap forming groove 16 in the drawings) is formed, and the air leak gap forming groove 16 is formed smaller than the nozzle insertion gap forming groove 15.

Further, the second heat sealing plate (the main heat sealing plate) 10 has a frame-shaped contact portion 10a that corresponds to the ring-shaped flange 3b of the container 3 and abuts the entire surface of the flange 3b.
have.

When the container 3 containing the contents 4 is filled with inert gas using the above-mentioned device and sealed with the sealing sheet 5, the containers 3 are sequentially moved in the direction of the arrow in the figure, and the container 3 is first placed in the sealing sheet covering position A. At the position reached, the opening of the container 3 is covered with the sheet 5.
Next, when the container 3 reaches the lower position B of the first heat-sealing plate 9, the first heat-sealing plate 9 is lowered, and the contact portion 9a heated to a predetermined temperature is attached to the flange portion 3.
b is pressed to temporarily heat-seal the sealing sheet 5 to the periphery of the opening of the container 3 (ring-shaped flange 3b) using the first heat-sealing plate 9. In this case, as described above, the first heat sealing plate 9 is formed with the nozzle insertion gap forming groove 15 and the air leak gap forming groove 16 opposite thereto, so that the ring-shaped flange of the container 3 3b and the sealing sheet 5, as shown in FIG. 5, there is a nozzle insertion space 17 facing each other and an air leakage space 18 which is smaller than 17.
The nozzle 1 is inserted into the container 3 from the nozzle insertion gap
The two tips are inserted toward the air leak gap 18. Although there is no particular limitation at this time, it is preferable to arrange an elastic material such as a silicone pad in the nozzle insertion groove 15 of the first heat sealing plate 9. The tip of the nozzle 12 and the sealing sheet 5 can be brought into close contact with each other, and filling with inert gas, which will be described later, can be performed better.

At the same time as the temporary heat sealing by this first heat sealing plate 9, the ejection hole 13 at the tip of the nozzle 12 is
Inert gas is ejected into the container 3 from the air leak gap 18, and the air inside the container 3 is expelled from the container 3 through the air leak gap 18, thereby filling the container 3 with inert gas.

At this time, the inert gas introduced into the container 3 thermally expands due to the heating during temporary heat sealing.
Since the air leak space 18 for discharging gas from the inside of the container 3 is smaller than the nozzle insertion space 17, there is no loss of inert gas, and the inside of the container 3 can be sufficiently pressurized. Can be filled with inert gas.

Then, the container 3 is sent to the balance guide 14 arrangement position C (at this point the nozzle 12 is outside the container 3). This balance guide 14 holds down the sealing sheet 5 while moving from the container 3 from position B to position D, and removes inert gas when it enters the container 3 too much. Next, when it is sent to the lower position D of the second heat sealing plate 10, the second
The heat sealing plate 10 is lowered, and the contact portion 10a heated to a predetermined temperature presses the flange portion 3b to seal the second
The sealing sheet 5 is attached to the container 3 by the heat sealing plate 10.
The entire periphery of the opening (flange) is heat-sealed, and the nozzle insertion gap 17 and the air leak gap 1 are
8 is closed and the container 3 is sealed.

In this case, since the container 3 is filled with inert gas in a pressurized state at the time of filling the inert gas,
After filling with the inert gas, there is no air flowing into the container 3 until this second heat sealing is performed, and the inert gas is finally filled with an extremely high replacement rate with a residual oxygen content of 1% or less. can be done. Further, the temporary heat sealing and inert gas filling are performed simultaneously, and the nozzle 12 is immediately pulled out from the nozzle insertion gap 17 after the temporary heat sealing, so that the nozzle of the sealing sheet 5 is heated during the temporary heat sealing. The insertion gap 17 part and the air leak gap 18 part are heat-shrinked and become taut during the second heat sealing. Beautifully heat sealed.

Thereafter, the container 3 is advanced to the lower position E of the trimming device 11, the trimming device 11 is lowered, and the flange portion of the container 3 is removed by the trimming device 11.
The sealing sheet 5 is cut and trimmed from the outer peripheral edge of b.

Here, there is no particular restriction on the material of the container used in the present invention, but polypropylene layer - barrier layer -
A rigid container made of a multilayer barrier sheet made of polypropylene layers molded into an appropriate shape (circular or elliptical cup shape as shown in FIGS. 6 and 7) and dimensions can be suitably used. Further, nitrogen gas or the like can be suitably used as the inert gas.

According to the inert gas filling packaging method of this example,
Inserting the inert gas jetting nozzle 12 from nozzle insertion interval 17 and spouting inert gas from it, and smoothly pushing out the air in 3 from air leak interval 18 without loss of inert gas. The container can be filled efficiently, temporary heat sealing and inert gas filling using the nozzle 12 can be performed at the same time, and air leakage time can be reduced.
By making 18 smaller than the nozzle insertion distance 17, it is possible to fill the inside of the container 3 with inert gas under sufficient pressure, resulting in extremely high displacement with a residual oxygen content of 1% or less. rate is achieved.

In addition, as mentioned above, temporary heat sealing and inert gas filling are performed at the same time, and after temporary heat sealing,
Since the nozzle 12 is quickly pulled out from the nozzle insertion space 17, the nozzle insertion space 17 and the air leakage space 18 of the sealing sheet 5 are heat-shrinked due to the heating during the temporary heat sealing, and are heated to the second heat. When sealed, it becomes taut and the final heat seal can be performed neatly without wrinkles or the like.

Furthermore, in the above-mentioned apparatus, the bucket 2 in which the containers 3 are placed is automatically advanced sequentially in the direction of the arrow in the figure, and in the process, temporary heat sealing is performed by the first heat sealing plate 9 and actual heat sealing is performed by the second heat sealing plate 10. Since trimming is performed sequentially by the trimming device 11, packaging can be performed automatically and efficiently. Furthermore, there is no need to use impulse sealing as a heat sealing method, and therefore circular or oval containers such as those shown in Figures 6 and 7 can be used, and large-scale equipment such as a vacuum chamber is required. There is no need for it.

In addition, in the above device, since a flat nozzle is used as the nozzle 12, the nozzle insertion distance is 17.
The nozzle 12 can be formed narrowly.
Since a large number of jet holes 13 are formed at the tip, the diameter of which is smaller toward the tip, the flow direction of the inert gas in the container 3 is controlled, and since an air leak gap 18 is provided in the flow direction, the inert gas is The gas replacement rate is extremely high, and containers packaged with the above device can be retort sterilized well, and aerobic bacteria such as mold will not grow even during long-term storage.

In the above device, a flat nozzle with a large number of ejection holes is used, but the nozzle is not limited to this, and other configurations may be modified without departing from the gist of the present invention.

Effects of the Invention As explained above, according to the inert gas filling and packaging method of the present invention, even containers with complicated shapes such as oval shapes can be filled with inert gas efficiently using simple equipment and at low cost. A product with a residual oxygen content of 1% or less that can be packaged, reduce inert gas loss as much as possible, and reliably prevent the oxidation of the contents and the growth of aerobic bacteria. High substitution rates can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing an example of an inert gas filling packaging device used to carry out the method of the present invention, FIG. 2 is a schematic plan view of the device, and FIG. 3 is a perspective view showing the nozzle tip of the device. , Fig. 4 is a bottom view showing the first heat sealing disc of the same device, Fig. 5 is a sectional view showing a state in which the sealing sheet is temporarily heat-sealed around the periphery of the container 3 by the heat sealing disc, and Fig. 6 is a circular shape. FIG. 7 is a plan view showing an elliptical container, and FIG. 8 is a sectional view showing the container filled with inert gas and packaged. 3... Container, 4... Contents, 5... Sealing sheet, 9... First heat sealing plate, 10... Second heat sealing plate, 12... Nozzle, 15... Forming groove for nozzle insertion , 16... Air leak gap = formation groove, 17... Nozzle insertion gap =, 18... Air leak gap =.

Claims (1)

[Claims] 1. Cover the opening of the container containing the contents with a sealing sheet, and apply this sealing sheet to the container by using a heat sealing plate having a notch-shaped groove for inserting the nozzle and a groove for forming the air leak. Space for inserting the nozzle on the periphery of the opening and space for inserting the nozzle
At the same time, temporarily heat-sealing so as to form smaller air leak gaps, insert a nozzle tip into the container from the nozzle insertion gap, and blow out an inert gas into the container from the nozzle tip,
After introducing an inert gas into the container and expelling the air inside the container to the outside of the container through the air leak gap, the container is filled with inert gas, and then the nozzle is pulled out of the container. An inert gas filling packaging method characterized in that the container is sealed by heat-sealing a sealing sheet around the entire periphery of the opening of the container to close the nozzle insertion gap and the air leak gap.