JP2004182320A - Apparatus and method of gas replacement packaging - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method of gas replacement packaging, which retain an advantage of steam spraying while avoiding a high temperature and high humidity environment due to the use of steam. <P>SOLUTION: A container 6 containing a content such as rice is transferred in a chamber 10, which has a sectional shape similar to that of the container 6 and of a holder 16, by a transfer means. in the chamber 10, an inert nitrogen gas is sprayed into the container 6 in a pre-gas replacement area 3a, and then steam is sprayed likewise in a steam area 3b. Further, a nitrogen gas is sprayed again, while part of the residual steam is kept in the container 6, in a gas replacement area 3c. The steam is exhausted by an exhausting means 11 in the steam area 3b to make sure it never leak out to the ambient environment. A closing means 4 arranged next to the exit of the chamber 10 closes the container with a lid 8. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a gas replacement packaging method and apparatus for performing gas replacement with an inert gas on a container, such as a cup or tray, in which contents are placed and closing the container.
[0002]
[Prior art]
Conventionally, in order to make a package obtained by filling and closing a food or drink such as cooked rice, prepared foods, beverages and the like and closing it at room temperature for a long period of time, the amount of oxygen remaining inside the package is required. It is necessary to minimize deterioration of foods and drinks as much as possible. Therefore, a gas replacement package is used in which a gas such as air left in a head space in a container filled with contents is replaced with an inert gas such as nitrogen.
[0003]
As one of the gas replacement packaging, a steam is blown into a semi-rigid container body filled with contents near normal temperature while leaving a space portion to heat only the vicinity of the surface of the contents, and then an inert gas is blown into the space, thereby Method for producing a sealed container in which the steam and residual air in the part are replaced with an inert gas and the container body is immediately sealed with a lid, or a mixture of steam and an inert gas is blown to heat only the vicinity of the surface of the contents. Then, a method of manufacturing a sealed container has been proposed in which the air remaining in the space is replaced with an air-fuel mixture and the container body is immediately sealed with a lid (Patent Document 1).
[0004]
According to this method for manufacturing a sealed container, the space in the container is replaced by an inert gas or a mixture of steam and an inert gas, so that the amount of oxygen remaining in the space can be reduced to a very small amount. Water vapor heated only on the surface of the content deprives of latent heat and condenses, and adheres to the surface of the content as water droplets. The condensed water evaporates into steam after a short period of time after the inert gas is blown, until the container is sealed.After the container is sealed, the water vapor condenses during cooling to room temperature, and the inside of the container becomes negative pressure. I do. At this time, in the sealed container, a relatively flexible portion such as a bottom wall and a lid usually slightly bends to a position where the inner volume is reduced and the pressure balance between the inside and the outside is balanced. By making the amount of water vapor in the space relatively small, it is intended to prevent the shrinkage deformation from being large enough to lose commercial value.
[0005]
As described above, in the filling and sealing device, steam is sprayed before gas replacement, and after sealing and cooling, steam is condensed into water droplets or the like, so that the pressure inside the container is reduced. Depression is performed on the inner side. When the lid material is dented, it has been promoted that there is no expansion of the container due to deterioration in quality and the appearance is improved. In addition, when the content is cooked rice, the surface of the rice is sterilized by steam, and it becomes difficult for fungi such as mold to propagate. Further, the heat seal can be further stabilized by warming the container with steam before the heat seal.
[0006]
However, when the content is cooked rice or the like, it is necessary to spray a large amount of steam. In such a case, the steam-sprayed container is closed with a lid or the like, and then the steam occupying the headspace is occupied. Condensation causes a large decompression, which causes disadvantages such as a large distortion of the container and impairing the appearance. In addition, since a large amount of steam is used at a manufacturing site that manufactures such containers and packages in a large amount, it is difficult to completely prevent steam from leaking into the factory. Environment where bacteria can easily propagate. When the inspection machine is arranged, the high-temperature and high-humidity environment may cause malfunction of the computer device. Therefore, it has been considered that it is practically difficult to apply the spraying of the steam to the container with the content to the actual container and packaging. Furthermore, if the outside air is drawn into the container before the container is closed due to the decompression inside the container due to the condensation of steam, the inside of the container may be contaminated with fungi, but this outside air is drawn into the container. There was also a problem that it was difficult to completely prevent the phenomenon.
[0007]
[Patent Document 1]
JP-A-63-178918 (pages 3 and 4, FIG.)
[0008]
[Problems to be solved by the invention]
In gas replacement packaging, as described above, it is obtained by spraying steam such as decompression inside the container due to condensation of water vapor after cooling, sterilization of the surface of contents such as cooked rice, and preheating for good heat sealing. The advantage is hard to abandon. Therefore, while preventing the sprayed steam from leaking into the surrounding environment, by replacing a part of the steam in the container again with an inert gas, the problem caused by the spraying of the steam is reduced or eliminated. There are issues to be solved.
[0009]
SUMMARY OF THE INVENTION An object of the present invention is to provide a gas replacement packaging method and apparatus capable of avoiding a high temperature and high humidity inside a factory due to the use of steam, while securing the advantage of spraying steam. It is.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a gas replacement packaging method according to the present invention provides a gas replacement packaging method in which a container having contents has a cross-sectional shape substantially similar to a cross-sectional shape of the container and a cradle supporting the container. During the transportation of the container, steam is blown into the container, followed by gas replacement with an inert gas, and the container is closed after passing through the chamber.
[0011]
According to this gas replacement packaging method, when a container with contents is transported through the chamber, first, steam is blown into the container, whereby the gas in the container is replaced by steam, and the surface of the contents is changed by steam. Sterilized. As the steamed container is transported further through the chamber, gas replacement with an inert gas is performed. Since steam is blown in a chamber having a cross-sectional shape substantially similar to the cross-sectional shape of the container and the cradle supporting the container, it is easy to control the leakage of steam from the chamber, and the inside of the factory is hot and humid. Can be prevented. Even if gas leaks out of the chamber outlet, the gas turns into an inert gas, so that the surrounding environment does not become hot and humid as would occur if steam leaked out. During the period from the exit of the chamber to the completion of the closing of the container, the steam is cooled and partially condensed, and the phenomenon that the inside of the container is decompressed and the outside air is drawn in easily occurs. By performing gas replacement of the portion with an inert gas, it is possible to substantially eliminate such an outside air drawing phenomenon. Even if a small amount of steam remaining in the container is condensed, excessive pressure reduction does not occur in the sealed container, and the appearance of the sealed container can be maintained. Further, when the container is closed by heat sealing of a packaging material such as a lid material, a portion to be heat-sealed is preheated by steam, so that good heat sealing can be obtained.
[0012]
In this gas replacement packaging method, the pregas replacement can be performed by spraying the inert gas into the container before the steam is sprayed while the container is transported in the chamber. By performing the pre-gas replacement by blowing the inert gas, the outside air containing oxygen can be removed in advance, and the gas replacement efficiency can be improved. In addition, since the replacement gas is injected before and after the steam is blown in the chamber, it is possible to prevent the steam from leaking in the front-rear direction in the container transport direction. Furthermore, since the container with the contents is subjected to the spraying of the inert gas over the two regions before and after traveling in the chamber, the contents in the container are exposed to the inert gas for a long time as a whole. In particular, more oxygen remaining in the contents such as cooked rice can be expelled, and the removal rate of dissolved oxygen can be increased.
[0013]
In this gas replacement packaging method, it is preferable that air be exhausted from a position below a transport path of the container in a steam area of the chamber where the steam is blown. Since a large amount of steam and a highly sealed chamber are used, it is preferable to set the exhaust amount so that the inside of the chamber is slightly pressurized against the surrounding environment. The utility value of steam is higher in the high temperature state immediately after injection. By performing the exhaust at the lower side of the chamber, the low-value steam present below can be exhausted from the chamber. In addition, since the exhaust port may be contaminated, it is preferable to exhaust air in the lower position, which is a safe side in terms of hygiene, in the chamber.
[0014]
Further, the gas replacement packaging device according to the present invention has a cross-sectional shape substantially similar to the cross-sectional shape of the container containing the contents and the cradle supporting the container, and the container is supported by the cradle. A chamber conveyed inside by a conveying means, a steam jetting means arranged in the chamber and spraying steam on the container passing through the chamber, and the chamber arranged downstream of the steam jetting means in the chamber. An inert gas injection means for blowing an inert gas to the container passing through the inside; and a sealing means disposed following the outlet of the chamber for closing the container.
[0015]
According to this gas replacement packaging apparatus, the container with the contents is transported by the transporting means while being supported by the cradle, and the cross-sectional shape substantially similar to the cross-sectional shape of the container and the cradle supporting the container is exhibited. When passing through the inside of the chamber having steam, the steam injecting means disposed in the chamber blows steam onto the container, so that the inside of the container is filled with steam, the outside air is expelled, and the contents are removed. The surface is sterilized by steam. When the container filled with steam is further transported in the chamber, the inert gas injection means disposed downstream of the steam injection means blows the inert gas onto the container, so that one of the steam filled in the container is discharged. The part is replaced with an inert gas. The injected steam is prevented from flowing to the outlet side of the chamber where the opening for carrying out the container is formed by the inert gas injected from the inert gas injection means, and the steam leaks to the external environment through the outlet. Can be prevented. Even if gas leaks from the outlet of the chamber, the gas becomes an inert gas, so that the surrounding environment does not become hot and humid as would occur if steam leaked. Further, the container that has exited the chamber is sealed by a sealing means disposed following the outlet of the chamber, and even if the steam is cooled within a short period until the completion of the sealing, the amount of steam in the container is reduced. Therefore, it is possible to substantially prevent the outside air from being drawn into the container due to excessive pressure reduction.
[0016]
In this gas replacement packaging device, in the chamber, the steam passing through the boundary between a steam area where the steam is sprayed by the steam injection means and a gas replacement area where the inert gas is sprayed by the inert gas injection means, A labyrinth portion having a narrow gap left between the container and the container can be provided. In order to more efficiently prevent the sprayed steam from leaking into the surrounding environment, it is preferable to minimize the flow of steam to the outlet side of the chamber. Therefore, in the chamber, the boundary between the steam region and the gas replacement region is formed as a labyrinth portion in which a gap left between the steam region and the gas passing region is narrowed, so that the passage resistance when the steam tries to pass through the labyrinth portion is reduced. And steam can be efficiently prevented from flowing to the gas replacement region.
[0017]
In this gas replacement packaging apparatus, the chamber may be provided with a pre-inert gas injection means for blowing the inert gas onto the container passing through the chamber upstream of the steam injection means. Depending on the contents to be packed, it is required to reduce the amount of dissolved oxygen as much as possible to prevent deterioration. To reduce the amount of dissolved oxygen in the contents, it is effective to increase the temperature and lengthen the time of exposure to the replacement gas. Further, it is preferable that the steam injected into the chamber is prevented from leaking also on the inlet side of the chamber. Therefore, by providing the pre-inert gas injection means for blowing the inert gas to the container passing through the chamber upstream of the steam injection means, it is possible to secure a sufficient time for the contents to be exposed to the inert gas. In addition, it is possible to prevent the steam injected from the steam injection means from rising upward in the chamber to the upstream side of the conveyance and leaking from the inlet side of the chamber to the surrounding environment.
[0018]
In the gas replacement packaging apparatus provided with a pre-inert gas injection unit, in the chamber, a steam region where the steam is blown by the steam injection unit and a pre-gas replacement region where the inert gas is blown by the pre-inert gas injection unit. Can be a pre-labyrinth part in which a gap left between the container and the container passing therethrough is narrowed. In order to more efficiently prevent the sprayed steam from leaking into the surrounding environment, it is preferable that the flow of the steam to the inlet side of the chamber is suppressed as much as possible. Therefore, in the chamber, when the boundary between the steam region and the pre-gas replacement region is a pre-labyrinth portion in which the gap left between the steam region and the pre-gas replacement region is narrowed, the steam is likely to pass through the pre-labyrinth portion. The passage resistance is increased, and the steam can be efficiently prevented from flowing to the pregas replacement region.
[0019]
In this gas replacement packaging apparatus, an exhaust port connected to an exhaust unit can be formed in the chamber below the transport path of the container in a steam area where the steam is sprayed by the steam injection unit. Since the steam is continuously sprayed by the steam injection means, even if a part of the sprayed steam is condensed, it must be finally discharged from the chamber. Therefore, in the region where steam is blown, by forming an exhaust port connected to the exhaust means at a position below the transport path of the container, the steam is discharged from the chamber without going to the gas replacement region or the pre-gas replacement region. Can be guided. It is preferable to discharge the steam remaining below the container because the temperature of the steam is low and cannot be used for surface sterilization of the contents. It is preferable to connect the exhaust means to a duct or the like to collect steam without releasing it to the surrounding environment. In addition, the chamber is preferably maintained at a temperature of 100 ° C. or higher to prevent condensation of steam.
[0020]
In the gas replacement packaging device provided with an exhaust unit, the exhaust unit is a natural exhaust unit that performs natural exhaust from the exhaust port or a forced exhaust unit that forcibly exhausts and exhausts through the exhaust port. It is preferable to set the pressure to a pressure slightly higher than the surrounding environment. The exhaust unit can be configured as a natural exhaust unit or a forced exhaust unit, depending on, for example, the amount of steam sprayed. It is preferable to set the inside of the chamber to a pressure slightly higher than the surroundings in order to avoid drawing outside air into the chamber even in the case of forced exhaust as well as in the case of natural exhaust. Further, the exhaust port is preferably maintained at a temperature of 100 ° C. or higher in order to prevent steam condensation.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a gas replacement packaging method and apparatus according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic side view of a main part of a gas replacement packaging apparatus according to the present invention, FIG. 2 is a sectional view taken along line AA of the gas replacement packaging apparatus shown in FIG. 1, and FIG. FIG. 4 is a cross-sectional view, and FIG. 4 is a perspective view of a chamber arranged in a chamber station of the gas displacement packaging apparatus.
[0022]
The gas displacement packaging apparatus 1 shown in FIG. 1 is applied to a sterile filling and sealing step, and is a synthetic resin tray-like container 6 (only a part is denoted by a symbol. , Simply referred to as “container 6”) and filled with cooked rice 7 (see FIG. 2), and the inside of the container 6 containing cooked rice 7 is replaced with an inert gas such as nitrogen gas. This is a device for closing the cooked rice container 6 by heat-sealing the lid material 8 made of a treated synthetic resin film. The gas replacement packaging device 1 includes a sterile space station 2, a chamber station 3 for spraying steam and an inert nitrogen gas as a replacement gas, and a lid 6 And a package take-out station 5 for taking out the package 9 of the cooked rice 7 sealed with the lid 8.
[0023]
The aseptic space station 2 is a closed space including a transfer section 2a of the container 6 and a content filling section 2b located downstream of the transfer section 2a for filling the rice 7 as the content. The aseptic space station 2 is supplied with aseptic air from an aseptic air supply source (not shown), and the container 6 is aseptically dried. In the transfer section 2a, the container 6 is supplied to a receiving table 16 described later by a container supply mechanism (not shown). The container 6 placed on the cradle 16 is filled with cooked rice 7 as a content in the content filling section 2b. The outlet 2c of the aseptic space station 2 is provided with an air curtain 2d for blowing down aseptic air to prevent mixing of the aseptic air in the aseptic space station 2 and the gas in the subsequent chamber station 3.
[0024]
The chamber station 3 is a station for spraying steam and nitrogen gas as an inert gas onto the container 6 containing the cooked rice 7, and is provided with a pre-gas replacement region 3a, a steam region 3b, and a gas replacement region 3c in order from the upstream side. Have been. In FIG. 1, the chamber station 3 is depicted in a compact manner, but in each part of the pre-gas replacement area 3a, the steam area 3b, and the gas replacement area 3c, the transport section that is exposed to the gas and transported is set to a considerable length. . In the chamber station 3, a chamber 10, which will be described later, is provided, and the inside of the chamber 10 is transported by the container 6 supported by the receiving table 16. In the pre-gas replacement region 3a and the gas replacement region 3c, inert gas injection means 26 and 28 each composed of a nozzle for injecting an inert gas are provided above the chamber 10, and in the steam region 3b, the chamber 10 is provided. The steam injection means 27 which consists of a nozzle which injects steam is provided in the upper part of. Although not shown, the chamber 10 is provided with a heater for heating the chamber 10 to 100 ° C. or higher.
[0025]
In the chamber 10, a portion near the inlet of the pre-gas replacement region 3a, a connection portion between the pre-gas replacement region 3a and the steam region 3b, a connection portion between the steam region 3b and the gas replacement region 3c, and a portion near the outlet of the gas replacement region 3c. Are made labyrinth portions 10a, 10b, 10c and 10d by narrowing a gap formed between the container and the conveyed container 6. For the space in the chamber 10 above the container 6 containing the cooked rice 7, a partition 10e is used at the boundary between the pre-gas replacement area 3a and the steam area 3b, and the partition 10f is used at the boundary between the steam area 3b and the gas replacement area 3c. Can be used to partition. In the steam area 3b, an exhaust unit 11 is provided below a transport path through which the container 6 is transported. As shown in FIG. 2, the exhaust means 11 includes a duct 36 connected to an exhaust port 35 opened to the chamber 10, a blower 37 provided in the duct 36 for sucking and exhausting gas in the chamber 10, and an upstream of the blower 37. And a damper 38 for adjusting the displacement. The exhaust gas exhausted from the blower 37 is collected so as not to leak to the surrounding environment.
[0026]
It is sufficient for the sealing station 4 to have a known structure. The sealing station 4 heat seals the lid material roll 12 on which the lid material 8 has been wound and the lid material 8 unwound from the lid material roll 12 to the containers 6 containing the cooked rice 7 and also provides the lid material 8 for each container 6. And a cover material winding section 14 for winding up a cover material surplus portion 8 a generated by cutting the cover material 8. Aseptic air is supplied to the sealing station 4 to maintain sterility, and the lid 8 is sterilized by a UV lamp (not shown) before heat sealing. The lid material seal cut portion 13 includes an upper heat block 13a and a lower heat block 13b that operate in synchronization with each other, and heat-seales the container 6 and the lid material 8 by sandwiching and heating the container. In the illustrated example, the lid 8 can be simultaneously heat-sealed and the lid 8 can be cut with respect to the four containers 6. The lid 8 is heat-sealed to the container 6 in a state where the container 6 is covered with the lid 8, so that the package 9 of the cooked rice 7 is manufactured. The closed package 9 of the cooked rice 7 can be removed from the production line at the package removal station 5.
[0027]
The above-described stations of the aseptic space station 2, the chamber station 3, the closing station 4, and the package taking-out station 5 are sequentially arranged along the transport path of the upper traveling portion 15d of the magnetic conveyor 15 as a transport device. . The magnetic conveyor 15 includes a driving sprocket 15a, a driven sprocket 15b, and a chain 15c (see FIGS. 2 and 3) wound around the driving sprocket 15a and the driven sprocket 15b, and a magnet provided on the chain 15c as described later. Acts magnetically on the cradle 16 to transport the container 6. Water droplets that may adhere to the cradle 16 due to the condensation of the steam sprayed in the chamber station 3 are received by a water droplet receiver 17 arranged around the drive sprocket 15a. The pedestal 10 is then washed at the washing station 18 while being conveyed through the lower traveling portion 15e, and the pedestal 16 that has exited the washing station 18 is blown with hot air 19c on the side near the driven sprocket 15b. It is dried while traveling in a drying chamber 19 provided with an exhaust port 19b on the side near the drive sprocket 15a, and is carried into the aseptic space station 2 at a position returning to the upper traveling section 15d.
[0028]
The chamber 10 is provided with a chamber 10 shown as a perspective view in FIG. The chamber 10 has a flat upper plate 20, a bottom portion 22 having an increased interval in the central region with respect to the upper plate 20, and a shelf portion in which the right and left sides are connected to the bottom portion 22 at a high position via the upright portions 22 a and 22 a. 23, 23, and short side wall plates 24, 24 connected at both left and right ends of the upper plate 20 and the lower plate 21. An entrance opening 25a into which the container 6 containing the cooked rice 7 supported by the receiving table 16 is introduced and an exit opening 25b through which the container 6 is carried out are formed before and after the transport device. Therefore, the chamber 10 is surrounded by the upper plate 20, the lower plate 21, and the side walls 24, 24 around the transfer path, and is closed except for the exhaust means 11 and the inlet opening 25a and the outlet opening 25b. Chamber. As is clear from FIGS. 2 to 4, the cross-sectional shape of the chamber 10 is similar to the cross-sectional shape of the container 6 and the pedestal 16 supporting the container 6 and is slightly larger.
[0029]
The arrangement of the container 6 in the chamber 10 is shown in FIGS. As shown in FIGS. 2 and 3, the receiving table 16 is formed in a rectangular frame shape as a whole into which the main body 6 a of the container 6 enters at the center, and can pass through the chamber 10. The cradle 16 includes a magnet 30 and a sliding member 31. The container 6 is supported by the receiving base 16 by placing the flange 6b formed around the opening on the receiving base 16, and is conveyed by the magnetic conveyor 15 in this state. That is, in the magnetic conveyor 15, a pair of chains 15c, 15c is wound around both driving sprockets 15a and driven sprockets 15b on the left and right in the transport direction, and magnets 32, 32 provided on the chains 15c, 15c are provided on the receiving base 16. The container 6 is conveyed by acting magnetically with the magnet 30 provided. Each chain 15c is attached to the device frame 33 and guided by a guide rail 34 arranged parallel to the shelf 23 formed on the lower plate 22 of the chamber 10 so that the chain 15c does not loosen during running. Being driven. With such a structure, the magnets 32 can run close to the lower surfaces of the shelves 23 formed on the lower plate 22 of the chamber 10. The sliding members 31, 31 are formed of a low-friction material so that the receiving table 16 can be smoothly slid and conveyed on the shelves 23, 23.
[0030]
As shown in FIG. 3, in the labyrinth portion 10 c, a portion rising from the bottom portion 22 of the chamber 10 and connecting to the shelf portion 23 is formed into a copying portion 40 that is curved according to the shape of the main body portion 6 a of the container 6. Therefore, in the region where the labyrinth portion is not formed as shown in FIG. 2, the labyrinth portion 10 c has a larger size than the large gap 42 formed between the bottom portion 22 and the right-angled rising portion 22 a and the main body portion 6 a of the container 6. The gap 41 formed between the copying portion 40 and the main body 6a of the container 6 is extremely narrow, and has a structure in which a gas such as steam or nitrogen gas hardly passes due to a large flow path resistance. The gas, especially steam, injected into the chamber 10 becomes difficult to flow into the pre-gas replacement region 3a or the gas replacement region 3c by the labyrinth portions 10b and 10c, and is exhausted by the exhaust means 11. Further, the nitrogen gas present in the pre-gas replacement region 3a or the gas replacement region 3c is also prevented from leaking to the inlet opening 25a or the outlet opening 25b by the labyrinth portions 10a and 10d. Except for the labyrinth part, the chamber 10 has a structure in which the gap 42 between the chamber 10 and the container 6 has a margin. Therefore, it is advantageous when a nozzle for cleaning the inside of the chamber 10, such as CIP or SIP, is provided. Although the chamber of the present invention is not used, the transfer of the container by the magnetic conveyor and the formation of a labyrinth at the entrance and exit sides to narrow the passage are already proposed and filed by the present applicant. (Japanese Patent Application No. 2002-216287).
[0031]
The operation of the present embodiment will be described. In this embodiment, a chamber 10 having a cross-sectional shape substantially similar to the cross-sectional shape of the container 6 and the cradle 16 supporting the container 6 is combined with spraying of steam. Is the feature. When the container 6 filled with the cooked rice 7 is carried into the chamber 10 through the inlet opening 25a, first, in the chamber 10, nitrogen gas, which is an inert gas, is blown in the pregas replacement region 3a to perform pregas replacement. Then, steam is sprayed on the container 6 in the steam area 3b. By blowing nitrogen gas into the container 6 before the steam is blown, the outside air entering the head space or the like in the container 6 is replaced with the nitrogen gas. By performing gas replacement at an early stage when the container 6 containing the cooked rice 7 travels in the chamber 10, the outside air containing oxygen can be removed in advance, and the gas replacement efficiency can be improved.
[0032]
Thereafter, the nitrogen gas is again blown in the gas replacement region 3c while the container 6 having been subjected to the pregas replacement and the spraying of the steam is transported in the chamber 10. When the cover 8 is heat-sealed by leaving the chamber 10 as it is after steam is sprayed, it is carried out through the outlet opening 25b of the chamber 10 and before the heat-sealing of the cover 8 is completed. Then, the cooling of the steam progresses, a part of the steam is condensed, and the phenomenon that the inside of the container 6 is decompressed and the outside air is drawn in easily occurs. However, in this embodiment, since the gas replacement with nitrogen gas is performed again before leaving the chamber 10, such a phenomenon of drawing in the outside air can be substantially eliminated, and the lid is closed at the closing station 4 in a state where the outside air is not drawn in. The container 6 containing the cooked rice 7 can be closed by the material 8. Since an appropriate amount of steam remains in the container 6, the steam condenses with cooling, thereby applying an appropriate negative pressure to the sealed container, so that the package 9 can have a good-looking appearance.
[0033]
In the chamber 10, since the injection with the inert gas is performed in the pre-gas replacement region 3a and the gas replacement region 3c before and after the steam is blown, the leakage of the steam before and after the container in the transport direction is blocked by the inert gas. Therefore, it is possible to effectively prevent the steam from leaking into the environment around the chamber 10 through a passage other than the exhaust unit 11. Further, since the container 6 containing the cooked rice 7 is blown with the inert gas in the two pre-gas replacement regions 3a and the gas replacement regions 3c before and after traveling in the chamber 10, the contents are kept for a long time. Exposed to an inert gas to increase the removal rate of dissolved oxygen.
[0034]
A labyrinth structure is employed at the connection between the pre-gas replacement region 3a and the gas replacement region 3c in the steam region 3b. Since the labyrinth portions 10b and 10c have a length of at least two containers 6 and 6, the labyrinth portions 10b and 10c exert the effect of preventing steam leakage by the labyrinth portions 10b and 10c irrespective of the position where the container 6 occupies during transportation. be able to. Further, in the vicinity of the inlet opening 25a and the outlet opening 25b of the chamber 10, the shape of the chamber 10 is made substantially similar to the shape of the container 6, and the gap 41 formed between the container 6 and the chamber 10 is narrowed to form the labyrinth portion 10b. , 10c are the same labyrinth portions 10a, 10d. The labyrinth portions 10a and 10d reduce the leakage of nitrogen gas from the inside as much as possible, and effectively prevent outside air from entering the inside. In addition, when there is a type change of the container 6 (the size of the container is changed), there is an advantage that the change as the device can be made only by changing the labyrinth portions 10a to 10d.
[0035]
In an area where steam is blown by the steam injection means 27, that is, in the steam area 3b, an exhaust port 35 connected to the exhaust means 11 is formed below the conveyed container 6, so that the steam is blown using the blower 37 or the like. Can be efficiently exhausted out of the production room. Since a large amount of steam and a highly sealed chamber 10 are used, it is necessary to use the damper 38 to determine the exhaust amount so that the inside of the chamber 10 is slightly pressurized against the pressure of the surrounding environment. preferable. Since the exhaust port 35 connected to the exhaust means 11 is formed at a position below the transporting path of the container 6, the priority is given to steam which does not use for sterilization of contents or preheating of the seal due to lower temperature below. And can be exhausted. Further, since the exhaust port 35 and the exhaust means 11 are easily contaminated, it is preferable to exhaust air below the container 6 which is a safe side for hygiene. The exhaust means 11 may be of a forced exhaust type, but is not necessarily limited to this. If the inside of the chamber 10 is kept at an appropriate pressurized state and there is no outside air circulating from below, the exhaust means 11 naturally exhausts from the exhaust port 35. Natural exhaust means may be used. Further, in order to prevent condensation of steam, it is preferable to keep the temperature of the exhaust means 11 at 100 ° C. or higher.
[0036]
【Example】
In an embodiment according to the present invention, per lane, the amount of nitrogen gas used in the pre-gas replacement region 3a is 40 to 400 liter / min, the steam is 0.5 to 80 kg / hour, and the nitrogen gas used in the gas replacement region 3c is The volume was 40-100 l / min. By performing the gas replacement packaging under these conditions, the inside of the package is slightly negatively pressured and the appearance is good without impairing the appearance of the container, and the working environment of the manufacturing plant is prevented from becoming hot and humid. be able to. The contents to which the present invention can be applied are not limited to cooked rice, but can be applied to all gas replacement packaging of beverages and prepared foods that are filled and sealed in containers.
[0037]
【The invention's effect】
Since the gas replacement packaging method and apparatus according to the present invention are configured as described above, the container with the contents has a cross-sectional shape substantially similar to the cross-sectional shape of the container and the cradle supporting the container. When transported through the chamber, the gas in the container is replaced by steam by first spraying steam into the container. As the steamed container is transported further through the chamber, gas replacement with an inert gas is performed. Therefore, it is possible to easily manage the leakage of steam from the chamber, and to prevent the surrounding environment from becoming hot and humid due to the leakage of steam while enjoying the advantage of using steam. That is, by performing the replacement gas with an inert gas before leaving the chamber, condensation occurs due to the cooling of steam between the outlet of the chamber and the completion of the sealing of the container, and the outside air drawing phenomenon caused by the decompression inside the container is reduced. It can be substantially eliminated. Since a part of the steam in the container is replaced by the inert gas, excessive pressure reduction does not occur in the sealed container due to the condensation of steam, and the appearance of the sealed container can be maintained. Further, the surface of the contents can be sterilized by steam by spraying the steam. Further, when the container is closed by heat sealing of a packaging material such as a lid material, a portion to be heat-sealed is preheated by steam, so that good heat sealing can be obtained.
[0038]
Further, since the steam and the inert gas (nitrogen gas) are sprayed in a chamber having a cross-sectional shape substantially similar to the cross-sectional shape of the container and the pedestal supporting the same, the space in the chamber is reduced. Is efficiently occupied by the container and the pedestal, so that a surplus space is reduced in the chamber having good airtightness. As a result, the team and the inert gas are used efficiently, the amount of use of the steam and the inert gas can be reduced, and the efficiency of replacing the steam and the inert gas can be improved. Furthermore, since the invasion of the outside air can be prevented as much as possible, the aseptic maintenance state can be improved.
[0039]
In the gas replacement packaging method and apparatus according to the present invention, the pre-gas replacement region and the gas replacement region are arranged before and after the steam region by spraying an inert gas to prevent the steam from leaking from the inlet opening or the outlet opening of the chamber. can do. By forming a labyrinth portion between the steam region and the pre-gas replacement region and the gas replacement region, it is possible to prevent the steam from leaking to the pre-gas replacement region and the gas replacement region. Further, by forming an exhaust port connected to the exhaust means corresponding to the steam area, the steam can be collected. In addition, if outside air enters the inside of the package, the inside may be contaminated with fungi. According to the present invention, the container with contents is conveyed in a highly sealed chamber to prevent the outside air from being mixed. It can be prevented in advance. Further, by making the vicinity of the inlet opening and the outlet opening of the chamber a labyrinth part having a narrow gap between the container and the chamber, it is possible to effectively prevent the outside air from entering the inside. Further, by providing the exhaust means at a position below the container transport path in the steam area, it is possible to prevent the outside air from entering the chamber due to wraparound.
[Brief description of the drawings]
FIG. 1 is a schematic side view of a main part of a gas replacement packaging apparatus according to the present invention.
FIG. 2 is a sectional view taken along the line AA of the gas replacement packaging apparatus shown in FIG.
FIG. 3 is a cross-sectional view of the gas replacement packaging device shown in FIG.
FIG. 4 is a perspective view of a chamber arranged in a chamber station of the gas exchange packaging apparatus.
[Explanation of symbols]
1 Gas replacement packaging equipment 2 Sterile space station
2a Transfer section 2b Contents filling section
3 Chamber station 3a Pre-gas replacement area
3b Steam area 3c Gas replacement area
4 Sealing station 5 Package removal station
6 container 6a main body 6b flange 7 cooked rice
8 lid material 9 package
10 Chamber 10a, 10b, 10c, 10d Labyrinth part
11 exhaust means 12 lid material roll
13 Cover Material Seal Cut 15 Magnetic Conveyor
15a driven sprocket 15b driven sprocket
15c chain
15d Upper traveling part 15e Lower traveling part
16 cradle
20 upper plate 21 lower plate
22 Bottom 22a Upright 23 Shelf
24 Side wall plate 25a Inlet opening 25b Outlet opening
26, 28 Inert gas injection means 27 Steam injection means
30, 32 magnet 31 sliding material 33 device frame
34 Guide Rail
35 Exhaust port 36 Duct 37 Blower
40 Copying part 41, 42 Clearance

Claims (9)

While the container with the contents is being conveyed in a chamber having a cross-sectional shape substantially similar to the cross-sectional shape of the container and the pedestal supporting the container, steam is blown into the container, A gas replacement packaging method comprising performing gas replacement with an active gas, and sealing the container after passing through the chamber. The gas replacement packaging method according to claim 1, further comprising performing a pre-gas replacement by spraying the inert gas into the container before spraying the steam while the container is being transported in the chamber. 3. The gas replacement packaging method according to claim 1, further comprising evacuating from a position below a transport path of the container in a steam area of the chamber where the steam is blown. 4. A chamber which has a cross-sectional shape substantially similar to the cross-sectional shape of the container containing the contents and the cradle supporting the container, and which is conveyed inside by the conveying means in a state where the container is supported by the cradle; A steam injection unit disposed in the chamber and spraying steam on the container passing through the chamber; an inert gas disposed in the chamber downstream of the steam injection unit and passing through the chamber; A gas replacement packaging apparatus comprising: an inert gas injection means for spraying water; and a sealing means disposed following the outlet of the chamber and for sealing the container. In the chamber, a boundary between a steam area where the steam is blown by the steam injection means and a gas replacement area where the inert gas is blown by the inert gas injection means is left between the container passing therethrough. 5. The gas replacement packaging device according to claim 4, wherein the labyrinth portion has a narrow gap. The pre-inert gas injection means for spraying the inert gas to the container passing through the chamber at an upstream of the steam injection means is provided in the chamber. Gas replacement packaging equipment. In the chamber, a boundary between a steam area where the steam is sprayed by the steam injection means and a pre-gas replacement area where the inert gas is sprayed by the pre-inert gas injection means is left between the container passing therethrough. 7. The gas replacement packaging device according to claim 6, wherein the pre-labyrinth portion has a narrow gap. 5. The gas replacement according to claim 4, wherein an exhaust port connected to an exhaust unit is formed below the transport path of the container in a steam area where the steam is blown by the steam injection unit in the chamber. 6. Packaging equipment. The evacuation unit is a natural evacuation unit that performs natural evacuation from the evacuation port or a forced evacuation unit that performs forced evacuation through the evacuation port. 9. The gas replacement packaging device according to claim 8, wherein:

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