JP2005119718A - Sealed container manufacturing method, and sealed container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealed container manufacturing method high in production efficiency for a sealed container capable of being used in a wide temperature zone in fields such as chilled sales, hot-warmer sales, warming in a hot water bath and sterilization with hot water without decompression deformation in a low-temperature condition, expansion deformation in a high-temperature condition and the like. <P>SOLUTION: The seal container manufacturing method for the sealed container having a container body to store contents and a sealant to seal an opening part of the container body comprises a content filling step, a step of covering the sealant on the opening part of the container body, and an adhering step of adhering the sealant along the entire periphery of a flange part of the container body, and further comprises a deaeration step of a head space before the adhering step, a pressing step of pressing the sealant downwardly while the sealant is joined with the entire periphery of the flange part of the container body after the step of covering the sealant, and an evacuating step of evacuating the head space after the adhering step. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  In the present invention, after contents such as soup and meat sauce are filled into a cup-shaped or tray-shaped container body leaving a head space, a sealing material is adhered and sealed to the peripheral edge of the opening of the container body by heat sealing or the like. The present invention relates to a sealed container manufacturing method and a sealed container.

  2. Description of the Related Art Conventionally, there is a storage container in which a cup-shaped or tray-shaped semi-rigid container is filled with liquid contents such as beverages, soups, and sauces, and is sealed by heat sealing using a thin and flexible sealing material. In this case, generally, the contents are filled up to the opening edge of the container, so-called full filling is not performed, and a certain space (head space) has been provided. This is because when full filling or close to full filling, the contents may adhere to the heat seal flange during filling or conveyance, causing heat seal failure. In addition, the contents spill out of the container during filling, causing the filling machine to become dirty. Further, in use, the contents may be spilled when the lid is peeled off and opened or after opening.

In view of the above points, it is better to have a larger head space. In this case, the internal pressure of the container changes greatly as the temperature in the container changes, the container deforms under reduced pressure at low temperatures, and positive pressure deformation or heat seal at high temperatures. The part was damaged. Therefore, the head space is managed in a very narrow range so as to satisfy these conditions, and the container temperature during distribution or storage is limited to a very narrow range.
Therefore, as shown in FIG. 9, as a sealing material for reducing the head space, a sealed container 1 ′ sealed by using a drop lid 2 ′ at the opening of the container body 11 ′ filled with the contents 12 ′ is provided. Proposed.

However, this type of drop lid type can solve the above problems, but has problems such as requiring lid processing, requiring some rigidity for handling, and increasing the amount of material used. It was. In addition, since it is a single wafer supply, when replacing the headspace with gas, the replacement rate does not increase, a special lid supply device is required, and aseptic filling is difficult to sterilize.
Therefore, although there are the above-mentioned problems, since the head space can be easily reduced, a sheet-like sealing material has been preferably used in this field.
In addition, when using a sheet-like sealing material, if there is a head space during heat sealing, the volume of the head space expands due to the heat of the heat sealing, causing a heat seal failure or a vertical seal on the heat sealing part. It sometimes occurred. In such a case, a method has been adopted in which a head space is reduced as much as possible by providing a deaeration board in the heat seal head. Moreover, such a phenomenon becomes conspicuous when the high temperature contents are filled and the head space is replaced with gas.

  Also, after filling the container body with the high-temperature contents leaving the head space, and then blowing an inert gas into the container body to replace most of the water vapor and air in the head space with the inert gas, a part of Heat seal the sealing material to leave, and then lower the pressing body having a downward convex surface and apply it to the sealing material, slightly dent the sealing material, and remove some of the headspace gas in the gap between the unheated seals A method has been proposed in which an unheat-sealed portion is immediately heat-sealed after being discharged (see, for example, Patent Document 1 by the present applicant).

Japanese Patent No. 2701457 (refer to “Means for Solving the Problems” in the patent specification and FIG. 1 of the drawings)

  According to this method, a part of the sealing material is pushed with a pressing body while leaving a non-heat-sealed portion, and is slightly recessed to heat-seal, so that the water vapor pressure generated from the high-temperature contents and the gas in the head space The internal pressure accompanying the expansion and part of the gas in the head space is discharged from the gap between the unheated seals. And since an unheat-sealed part is heat-sealed after this, there exists an advantage that a sealing material does not swell so that a vertical scissors generate | occur | produces and it can maintain high sealing performance.

However, in this method, it is assumed that the contents are filled into the container body at a high temperature above a certain level (about 70 ° C. to 80 ° C. in the case of the embodiment described in Patent Document 1 above). There is a problem that it is not suitable for contents having a deteriorating property. Moreover, since the method described in Patent Document 2 is basically proposed for the purpose of preventing heat-seal failure caused by high-temperature filling, it cannot prevent decompression deformation of the container body due to the temperature drop of the contents. . That is, deformation of the container can be prevented in the temperature range near the filling temperature, but in the temperature range including a low temperature lower than the filling temperature (from room temperature to about 5 ° C.), the internal pressure of the container is negative as the head space gas contracts. Thus, there is a problem that deformation at a reduced pressure is likely to occur when the temperature is lower than the reduced pressure strength of the container body.
In addition, since heat sinking is performed after leaving a part of the seal, and then the entire sealing material is heat sealed, there is a problem that the number of steps increases and the manufacturing cost of the sealed container increases.

  The present invention has high production efficiency, no increase in materials used, deformation under reduced pressure due to negative pressure at low temperature after filling and sealing, expansion deformation due to positive pressure at high temperature, deformation of the container body during action such as dropping, or It can be used in a wide range of temperatures from low to high, such as chilled sales, hot-warmer sales, hot water baths, hot water sterilization, etc., and low oxygen filling and highly aseptic filling. It is an object of the present invention to provide a method for producing a sealed container and a sealed container by this method.

In order to achieve the above object, the invention described in claim 1 is directed to a sealed container manufacturing method having a container body that contains the contents and a sealing material that seals the opening of the container body. A filling step, a step of covering the opening of the container body with a sealing material, and an adhesion step of adhering the sealing material along the entire circumference of the flange portion of the container body, before the adhesion step, A head space deaeration process step is provided, and after the step of covering the sealing material, a pressing step of pressing the sealing material downward in a state where the sealing material is joined to the entire circumference of the flange portion of the container body is provided, and after the bonding step In this method, a negative pressure treatment step for making the head space negative pressure is provided.
According to this method, by applying a pressing process to the center of the sealing material and a negative pressure process, the sealing material can be easily deformed into an uneven shape following the change in internal pressure in the head space, and the head space. The capacity of can be reduced.
As a result, it is possible to prevent deformation of the container body or peeling or cutting of the sealing material at the time of negative pressure after filling and sealing, at the time of positive pressure, dropping, etc., and further, performing deaeration treatment and negative pressure treatment, By applying a pressing process to the center of the sealing material, low oxygen filling and highly aseptic filling can be performed.

According to a second aspect of the present invention, the deaeration process is performed by hot-filling the contents and replacing at least a part of the head space with steam, and the negative pressure process is performed by cooling the contents and the head space. The deaeration process may be performed by gas content at least part of the head space with a content-absorbing gas having a property of being absorbed by the content. Alternatively, the negative pressure treatment step may be performed by causing the contents to absorb the contents-absorbing gas. As the content-absorbing gas, as described in claim 4, a gas containing carbon dioxide or laughing gas can be used.
Further, as described in claim 5, the deaeration process step is performed by denting at least a part of the container body before the bonding process, and the negative pressure process step is performed by releasing the recess of the container body. You may make it perform.

In addition, in the said press process, as described in Claim 6, it is good to press and extend the center part of a sealing material with a convex-shaped press body, and to form a thin part thinner than a peripheral part at a center part.
According to this method, it is possible to easily form a flexible thin portion formed in the center of the sealing material that deforms following the change in the internal pressure of the head space. Further, deformation of the container body or peeling of the sealing material during cutting, prevention of cutting, low oxygen filling, and high level aseptic filling can be performed more reliably.
In this case, as described in claim 7, the thin portion may be 10% to 80% of the area of the opening.

The object of the present invention can be achieved by the container according to claim 8 or 9 as the container.
That is, the invention according to claim 8 is a sealed container having a container main body for storing the contents and a sealing material for sealing the opening of the container main body. The thin-walled portion is thinner than the peripheral portion.
In this case, as described in claim 9, the area of the thin portion is preferably 10% to 80% of the area of the opening.

According to the present invention, deformation under reduced pressure due to negative pressure at low temperature after filling and sealing, expansion deformation due to positive pressure at high temperature, deformation of the container body during operation such as dropping, peeling of the sealing material, cutting is prevented, A sealed container that can be used in a wide temperature range from low temperature to high temperature such as chilled sales, hot warmer sales, hot water bathing, hot water sterilization, etc. can be obtained.
Moreover, low oxygen filling and highly aseptic filling can be performed.

[Embodiment of the Invention]
DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a sealed container manufacturing method and a sealed container according to the method of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view illustrating a manufacturing process of a sealed container according to the first embodiment of the present invention.
This manufacturing process includes the first step (i) to the fifth step (v).
In the first step (i), the contents 12 are filled at a high temperature (for example, about 70 ° C.) while leaving the head space 13 while supporting the cup-shaped container body 11 constituting the sealed container 1. Then, before reaching the second step (ii), at least a part of the air in the head space 13 is replaced with the steam by the high-temperature filling described above, and a deaeration process is performed. The temperature of the contents can be arbitrarily set according to the effect of the deaeration treatment. For example, the content may be filled at a higher temperature when the effect is insufficient, or at a lower temperature when the effect is excessive.
In addition, the container main body 11 is supported by engaging the flange 11a formed in the opening part periphery of the container main body 11 with the support link 20 of the manufacturing apparatus of a sealed container.

In the second step (ii), the sealing material 2 that seals the opening of the container main body 11 is supplied to the opening, and the sealing material 2 is pressed against the flange 11a by the heat seal device 22 and bonded to the flange 11a. To do. Adhesion of the sealing material 2 by the heat sealing device 22 is performed over the entire circumference of the flange 11a.
In the present invention, when the bonding is performed by heat sealing, the heat sealing may be performed once or may be performed two or more times and a plurality of times. In addition, after heat sealing, in order to effectively accelerate the cooling and solidification of the heat sealing portion, the heat sealing portion may be forcibly cooled using a cooling plate or the like.
As the sealing material 2, a laminate material with a metal foil can be used. Specifically, a material comprising a coating layer / metal foil layer / adhesive layer / sealant layer, synthetic resin film layer / adhesive layer / metal What consists of a foil layer / adhesive layer / sealant layer etc. can be used.

  Here, as metal foil, aluminum foil, tin foil, copper foil, tin foil, etc., as coating, epoxy phenol coating, ethyl cellulose coating, various lacquers, etc., as synthetic resin film, biaxially stretched polyethylene terephthalate film, two An axially stretched nylon film, a polybutylene terephthalate film, or the like can be used.

  As the sealant layer, an olefin resin (low-medium-high density polyethylene, isotactic and syndiotactic polypropylene, propylene-ethylene copolymer, ethylene-vinyl acetate copolymer, ethylenically unsaturated carboxylic acid or Olefin resins graft-modified with anhydrides), polyamides or copolyamide resins having relatively low melting points to low softening points, polyesters or copolyester resins having relatively low melting points to low softening points, polycarbonate resins, heat seal lacquers, etc. Can be used.

Further, as the sealing material 2, a synthetic resin laminate material may be used, and specifically, a synthetic resin film layer / adhesive layer / barrier resin film layer / adhesive layer / sealant layer may be used. .
Here, as the synthetic resin film, a biaxially stretched polyethylene terephthalate film, an unstretched or biaxially stretched nylon film, a polybutylene terephthalate film, or the like can be used. As the barrier resin film, an ethylene / vinyl alcohol copolymer, Polyvinylidene chloride resin, polyamide or copolyamide resin, non-stretched or stretched film such as polyester or copolyester resin, and various deposited films can be used.

In the third step (iii), the convex head 23b of the pressing device 23 is pressed against the central portion of the sealing material 2, and the central portion of the sealing material 2 covered by the opening is stretched in the radial direction. Thereby, a thin part is formed in the central part of the sealing material 2.
In the fourth step (iv), the sealing material 2 is cut in the directions indicated by I and I on the outer periphery of the flange 11a and is cut into individual sealed containers 1.

  In the fifth step (v), a negative pressure process is performed in which the contents are cooled to liquefy the vapor G1 in the head space 13 to obtain a negative pressure state. As a result, the volume of the gas (vapor) in the head space 13 is reduced and negative pressure is generated, the slack of the sealing material 2 is removed, and the sealed container 1 becomes ready for shipment. This cooling may be forced cooling by spraying water, blowing air, or the like, but may also be natural cooling by leaving it at room temperature for a certain time.

FIG. 2 is a schematic diagram for explaining a manufacturing process of the sealed container according to the second embodiment of the present invention.
This manufacturing process includes the first step (i) to the sixth step (vi).
In the first step (i), the contents 12 are filled at room temperature (about 25 ° C.) with the head space 13 remaining while the cup-shaped container body 11 constituting the sealed container 1 is supported.
In addition, the container main body 11 is supported by engaging the flange 11a formed in the opening part periphery of the container main body 11 with the support link 20 of the manufacturing apparatus of a sealed container similarly to 1st embodiment.

In the second step (ii), the gas replacement device 21 is disposed in the opening of the container body 11, and replacement gas is blown into the head space 13 from the gas supply port 21 a of the gas replacement device 21, so that the air in the head space 13 And deaeration treatment. In the method in which the deaeration process is not performed by filling at a high temperature as in this embodiment, the contents can be filled into the container body at normal temperature, which is suitable for the contents that deteriorate at high temperatures.
The air in the head space 13 is exhausted through the exhaust port 21b between the gas replacement device 21 and the flange 11a. As a replacement gas that replaces air, an inert gas such as nitrogen is mainly used, and a content-absorbing gas such as carbon dioxide or laughing gas having the property of being absorbed by the content 12 is added to the inert gas. What was added in a fixed ratio can be used.

In the third step (iii), the sealing material 2 for sealing the opening of the container body 11 is supplied to the opening, and the sealing material 2 is pressed against the flange 11a by the heat seal device 22 and bonded to the flange 11a. To do. Adhesion of the sealing material 2 by the heat sealing device 22 is performed over the entire circumference of the flange 11a.
As the sealing material 2, the same material as in the first embodiment can be used.

In the fourth step (iv), the convex head 23a of the pressing device 23 is pressed against the sealing material 2, and the central portion of the sealing material 2 covered by the opening is stretched in the radial direction. Thereby, a thin part is formed in the central part of the sealing material 2.
In the fifth step (v), the sealing material 2 is cut at the outer periphery of the flange 11a and separated into individual sealed containers 1.
In the sixth step (vi), the content-absorbing gas G is absorbed by the content 12 and a negative pressure treatment is performed. This negative pressure treatment may be performed by leaving the sealed container 1 for a predetermined time or by applying vibration. In addition, the content-absorbing gas G2 may be absorbed by the content 12 by utilizing natural shaking at the time of shipment. Thereby, the slack of the sealing material 2 is removed.

FIG. 3 is a schematic diagram for explaining a manufacturing process of the sealed container according to the third embodiment of the present invention.
This manufacturing process includes the first step (i) to the sixth step (vi). In FIG. 3, the same members and portions as those of the sealed container 1 and the manufacturing process of the second embodiment shown in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.
In the first step (i), the contents 12 are filled at room temperature (about 25 ° C.) with the head space 13 remaining while the cup-shaped container body 11 constituting the sealed container 1 is supported.

In the second step (ii), as in the second embodiment, the gas replacement device 21 is disposed in the opening of the container body 11 and the air in the head space 13 is replaced with a replacement gas. In the second step (ii), a part of the bottom of the container body 11 is forcibly recessed to form the recess 16 during the gas replacement. In this embodiment, the process of forming the recess 16 is a deaeration process. The volume of the recess 16 formed in the bottom of the container body 11 must be capable of at least allowing the sealant 2 to sag in a sixth step (vi) described later. The recess 16 may be formed at least before the next bonding step, and may be formed before the filling step as long as the recess 16 is held. Further, the recess 16 is not limited to the bottom of the container body 11 and may be formed in the body or in both the bottom and the body.
In the third step (iii), the sealing material 2 that seals the opening of the container body 11 is supplied to the opening, and the sealing material 2 is pressed against the flange 11a by the heat seal device 22 so that all of the flange 11a is covered. Adhere over the circumference.

In the fourth step (iv), the convex head 23a of the pressing device 23 is pressed against the central portion of the sealing material 2, and the central portion of the sealing material 2 covered by the opening is stretched in the radial direction. Thereby, a thin part is formed in the central part of the sealing material 2.
In the fifth step (v), the sealing material 2 is cut at the outer periphery of the flange 11a and separated into individual sealed containers 1.
In the sixth step (vi), the depression of the concave portion 16 is removed by releasing the pressed state of the bottom of the container body 11 or by suction. Thereby, a negative pressure process is performed, the slack of the sealing material 2 is removed, and the sealed container 1 becomes in a state where it can be shipped.
The recess 16 may be released at any stage as long as it is after the bonding step in which the container body 11 in at least the third step (iii) is sealed with the sealing material 2.

FIG. 4 is a schematic diagram for explaining the manufacturing process of the sealed container according to the fourth embodiment of the present invention, which is a modification of the above-described first embodiment of the present invention.
This manufacturing process includes the first step (i) to the fifth step (v), and the same reference numerals are used for the same members and parts as those of the sealed container 1 and the manufacturing process of the first embodiment shown in FIG. The detailed explanation is omitted.
In the first step (i), the contents 12 are filled at a high temperature (for example, about 70 ° C.) leaving the head space 13. And until it reaches the second step (ii), the air in the head space 13 is replaced with the steam by the high-temperature filling described above, and a deaeration process is performed.

  In the second step (ii), the sealing material 2 that seals the opening of the container main body 11 is supplied to the opening, and the sealing material 2 is pressed by the pressing device 23a to be joined to the flange 11a. In the second step (ii), the convex head 23a of the pressing device 23 is further pressed against the central portion of the sealing material 2 in a state where the periphery of the sealing material 2 is constrained over the entire circumference, and the opening is covered. The central portion of the sealing material 2 is extended downward, and a thin portion is formed in the central portion of the sealing material 2.

In the third step (iii), the sealing material 2 is pressed against the flange 11a by the heat sealing device 22 and bonded to the flange 11a. Adhesion of the sealing material 2 by the heat sealing device 22 is performed over the entire circumference of the flange 11a.
In the fourth step (iv), the sealing material 2 is cut in the directions indicated by I and I on the outer periphery of the flange 11a and separated into individual sealed containers 1.
In the fifth step (v), the content is cooled to perform a negative pressure process in which the vapor G1 in the head space 13 is liquefied to obtain a negative pressure state.

FIG. 5 is a diagram illustrating a state in which a thin portion is formed on the sealing material 2 by the pressing device 23 in each manufacturing process described with reference to FIGS. 1 to 4, and FIG. FIG. 5B is a plan view showing how the central portion of the sealing material 2 is stretched, and FIG. 5C is a cross-sectional view in the II-II direction of FIG. 5B.
As shown in FIG. 5A, the pressing device 23 has a main body 23a and a downward convex head 23b attached to the main body 23a with an adjusting bolt 23c. The amount of expansion of the sealing material 2 can be adjusted by changing the amount of protrusion of the head 23b with respect to the main body 23a by the adjusting bolt 23c.
In addition, it is good for the ratio of the thin part formed by an extending | stretching process to be in the range of 10%-80% with respect to the area of the opening part of the container main body 11. FIG.

As shown in FIG. 5B, when the head 23 b of the pressing device 23 is pressed against the central portion 2 b of the sealing material 2, the central portion 2 b is in a radial direction with respect to the bonding portion 2 a between the flange 11 a and the sealing material 2 ( In the direction indicated by the arrow in the figure).
In order to selectively stretch the central portion 2b of the sealing material 2, the central portion 2b may be heated to a higher temperature than other portions before or simultaneously with pressing, and the synthetic resin layer may be softened to be easily stretched. As a method of making the central portion 2b higher than other portions, any method such as hot air infrared heating or heating of the head 23b of the pressing device 23 can be selected.
As a result, as shown in FIG. 5C, the central portion 2b is thinner than the adhesive portion 2a and is formed as a thin portion that is more flexible than the other portions. When the negative pressure or positive pressure is applied to the container main body and the sealing material 2 due to the change in the internal pressure of the head space 13, or when an impact such as a drop is applied, the thin-walled portion is deformed more than the other portions. And the force which acts on the adhesion part 2a of the sealing material 2 and the flange 11a of the container main body 11, and the deformation | transformation force which acts on the trunk | drum and bottom part of the container main body 11 are relieve | moderated.

  FIG. 6 is a diagram showing changes in ambient temperature and changes in the internal pressure of the head space of the sealed container. The vertical axis shows the internal pressure in the head space of the sealed container 1 as a differential pressure from the atmospheric pressure, and the horizontal axis shows the ambient temperature. Show. Here, the limit strength at which the container body 11 of the sealed container 1 is deformed under reduced pressure is defined as the decompression strength −p, and the limit strength P1 at which the container body 11 is positively deformed and the heat seal portion 2a between the container body 11 and the sealing material 2 are positive. Of the limit strength P2 peeled off by pressure, the one having a smaller value is defined as positive pressure strength P.

[A. When no processing is performed]
Now, when the contents are filled at a temperature near 30 ° C., the internal pressure of the head space of the sealed container 1, that is, the internal pressure of the container changes as indicated by A (dotted line) in FIG.
In the chilled region of 5 ° C., the internal pressure of the container is higher than the reduced pressure strength −p, and thus does not deform. As the atmospheric temperature increases, the internal pressure of the container increases, and the sealing material 2 is slackened from the room temperature to the 40 ° C. level, and the internal pressure does not act. However, when the temperature exceeds 40 ° C., the internal pressure begins to rise again, and when the ambient temperature reaches the 60 ° C. level, the internal pressure of the container exceeds the positive pressure strength P, and the container main body 11 is positively deformed, or the sealing material 2 is heat sealed. Peel from the part.

[B. When deaeration and negative pressure are applied]
On the other hand, as deaeration processing and negative pressure processing,
(1) The contents are hot-filled at a temperature near 60 ° C., at least a part of the head space is replaced with steam, and after sealing with the sealing material 2, the contents and the head space are cooled.
(2) The contents are filled at room temperature, and at least a part of the head space is replaced with a contents-absorbing gas having the property of being absorbed by the contents, and after sealing with the sealing material 2, the contents-absorbing gas Is absorbed into the contents.
(3) The contents are filled at room temperature, and at least a part of the container body 11 is recessed, and after sealing with the sealing material 2, the recess is released.
When the processing such as the above is performed, the pressure in the sealed container body 1 is dependent on the temperature dependence of the vapor pressure and the solubility of the content-absorbing gas as shown in FIG. Strictly speaking, although the shape of the curve changes slightly due to the above, it changes in a state where A (dotted line) in FIG. 6 is shifted to the high temperature side. Under this condition, the internal pressure of the container does not exceed the positive pressure strength P and the container is not deformed or peeled off from the heat seal portion of the sealing material 2 in the 80 ° C. level. However, in the chilled region of 5 ° C., the internal pressure of the container is equal to or lower than the reduced pressure strength −p, and the container body 11 is deformed under reduced pressure.
Therefore, in the container shown by A (dotted line) and B (broken line) in FIG. 6, it is possible to prevent container deformation and peeling of the sealing material 2 in a wide temperature range from the chilled region at 5 ° C. to the hot region at the 80 ° C. level. Cannot be used.

[C: When the treatment of the present invention is performed]
In contrast, when the degassing process and the negative pressure process are performed and the sealing material 2 is pressed as in the present invention, the pressing process of the sealing material 2 is performed by A (dotted line) and B (broken line) in FIG. ) To extend the temperature range where no internal pressure is generated. That is, the pressing process is performed from the chilled region of 5 ° C. to the hot temperature of the 80 ° C. level so that the decompression deformation and the positive pressure deformation of the container body 11 and the heat seal portion are not destroyed. At the same time, when the degree of the deaeration process is adjusted, the curve can be shifted left and right, and the pressure in the sealed container 1 can be changed as shown by C (solid line) in FIG. As a result, it is possible to prevent container deformation and peeling of the sealing material in a wide temperature range from a chilled region of 5 ° C. to a hot region of 80 ° C. level.
In the present invention, the degree of deaeration treatment and negative pressure treatment and the amount of expansion of the sealing material are as described above, the operating temperature range of the container, the rigidity of the container body 11, the slackness of the sealing material, and the positive pressure destruction of the heat seal part. It can be set as appropriate in consideration of strength, filling amount of contents, head space amount, and the like.

FIG. 7 is a cross-sectional view of the sealed container 1 manufactured by the above-described method for manufacturing a sealed container according to the present invention, and includes a cup-shaped container body 11 that contains the contents and a seal that seals the opening of the container body 11. In the sealed container 1 having the material 2, the sealing material 2 is stretched and has a central portion as a thin portion thinner than the peripheral portion (see FIG. 5C).
The head space 13 is filled with low oxygen and highly sterile by the deaeration process and the negative pressure process described above, and is deformed following the change in the internal pressure of the head space 13 so that the negative pressure is maintained. It is possible to reliably prevent deformation of the container body or peeling or cutting of the sealing material 2 at the time of positive pressure or dropping.
In addition, it is preferable that the area of the thin part is 10% to 80% of the area of the opening to obtain the above-described effect.

As mentioned above, although the preferable embodiment was shown and demonstrated about the manufacturing method of the sealed container of this invention, this invention is not limited to embodiment mentioned above, A various change implementation is possible in the scope of the present invention. Needless to say.
For example, as shown in FIG. 8, in step (ii) of the first embodiment, the sealing material 2 is supplied in a state where a gap 22a is provided between the sealing material 2 and the container body 11, and the head is passed through this gap. After the replacement of air and steam in the space 13 (deaeration process), the heat sealing device 22 may be used to press and seal the sealing material 2 against the flange 11a.

  Also, (1) steam and cooling described above, (2) gas replacement of the contents-absorbing gas and contents absorption of the gas, and (3) a deaeration process in which a part of the container body is recessed and the dent is released. The negative pressure processing may be performed by selecting one of the above (1) to (3), or selecting two or more.

  Further, in the above description, the content-absorbing gas such as carbon dioxide or laughing gas is included in an inert gas such as nitrogen gas, and the content-absorbing gas is absorbed by the content, thereby performing negative pressure treatment. However, if the negative pressure treatment of the head space can be performed after sealing with the sealing material 2, the content may be cooled.

  The present invention is applicable not only to foods and beverages but also to sealed containers that contain all kinds of contents such as cosmetics and industrial products such as industrial oils and fats. Moreover, the present invention can be applied not only to cup-shaped containers but also to tray-shaped containers.

It is the schematic explaining the manufacturing process of the sealed container concerning 1st embodiment of this invention. It is the schematic explaining the manufacturing process of the sealed container concerning 2nd embodiment of this invention. It is the schematic explaining the manufacturing process of the sealed container concerning 3rd embodiment of this invention. It is the schematic explaining the manufacturing process of the sealed container concerning 4th embodiment of this invention. FIGS. 4A and 4B are diagrams illustrating a state in which a thin portion is formed on the sealing material by the pressing device, FIG. 4A illustrates a state in which the sealing material is stretched, and FIG. 5B illustrates a cross-section in the II-II direction in FIG. Is shown. It is a figure which shows the relationship between atmospheric temperature change and the internal pressure change of the head space of a sealed container. It is sectional drawing which shows the sealed container of this invention. It is the schematic explaining the further another manufacturing process of the sealed container of this invention. It is sectional drawing of the sealed container using a drop lid concerning the prior art example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sealed container 2 Sealing material 2a Adhesive part 2b Center part 11 Container main body 11a Flange 12 Contents 13 Head space 20 Support ring 21 Gas displacement apparatus 21a Gas supply port 21b Exhaust port 22 Heat seal apparatus 23 Press apparatus 23a Apparatus main body 23b Head G Content-absorbing gas

Claims (9)

In a manufacturing method of a sealed container having a container main body for storing contents and a sealing material for sealing an opening of the container main body,
Filling process of contents;
Covering the opening of the container body with a sealing material;
An adhesion step of adhering the sealing material along the entire circumference of the flange portion of the container body,
Before the bonding step, a headspace deaeration process is provided,
After the step of covering the sealing material, a pressing step of pressing down the sealing material in a state where the sealing material is joined to the entire circumference of the flange portion of the container body is provided.
After the bonding step, provided a negative pressure treatment step to make the head space negative pressure,
The manufacturing method of the sealed container characterized by these.   The deaeration process step is performed by hot-filling the contents, replacing at least a part of the head space with steam, and performing the negative pressure treatment step by cooling the contents and the head space. The manufacturing method of the sealed container of Claim 1 to do.   The deaeration process is performed by substituting at least a part of the head space with a content-absorbing gas having a property to be absorbed by the contents, and the negative pressure treatment process is performed by using the contents-absorbing gas as the contents. The method for producing a sealed container according to claim 1, wherein the method is carried out by absorbing it.   The said content absorptive gas contains a carbon dioxide or a laughing gas, The manufacturing method of the sealed container of Claim 3 characterized by the above-mentioned.   The deaeration treatment step is performed by denting at least a part of the container body before the bonding step, and the negative pressure treatment step is performed by releasing the depression of the container body. Method for manufacturing hermetically sealed containers.   The sealed container according to any one of claims 1 to 5, wherein in the pressing step, the central portion of the sealing material is pushed and stretched by a convex pressing body, and the central portion is a thin-walled portion thinner than the peripheral portion. Manufacturing method.   The method for manufacturing a sealed container according to claim 6, wherein the thin portion is 10% to 80% of the area of the opening. In a sealed container having a container body for storing contents and a sealing material for sealing the opening of the container body,
The sealed container is characterized in that the sealing member is stretched to have a thin central portion at a central portion thinner than a peripheral portion.   The sealed container according to claim 8, wherein an area of the thin portion is 10% to 80% of an area of the opening.

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