JP2019006419A - Packing container for heating - Google Patents

Abstract

To provide a packing container with a rectangular tray having long sides and short sides for heating with no deformation due to internal pressure during the heating, no falling down or no leakage of contents as well as no deformation after cooling down, keeping its shape firmly.SOLUTION: A packing container comprises a rectangular tray (2) with its opening made of long sides and short sides and a sealing film (3) for sealing the opening. The tray has a fusion part (221) where the sealing film is fused to the entire perimeter of opening, and there are vapor release parts (24) in some portions of the fusion part. The vapor release parts are arranged at one or more positions on each side deviated from the center of the long sides of the fusion part. The sheet thickness of the tray is 0.6 mm or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heating packaging container mainly used for a simple retort food that is cooked in a microwave oven or a hot water bath.

In recent years, retort foods have been stored using a pillow packaging bag with a sealant side of the plastic film aligned and the back seal and the top and bottom edges heat sealed, and a standing pouch, and placed in a packaging bag using a microwave oven, etc. There is a packaging bag container that heats as it is.
In order to heat such a packaging bag, in the pillow packaging bag, the back seal to be evacuated is heated upward. In the standing pouch, the steam vent is processed in advance with the bottom facing down, and the steam vent is preferentially opened by heating, and when the inside of the packaging bag rises to a certain internal pressure, It is designed to remove steam.
In the packaging bag, immediately before the opening of the vapor vent, the whole swells in a spherical shape, and the entire packaging bag moves due to the impact of the opening of the vapor vent, and the liquid and fixed contents inside are scattered. In addition to problems such as falling, standing pouches etc. have fallen. For this reason, in a state where the packaging bag is put in a large heat-resistant container, it has been in a situation where it must be heated.

  Therefore, rather than a packaging bag, a packaging container made of a sealing film that can be hermetically sealed by fusing to the opening of the tray is not heated for a tray formed by vacuum forming or pressure forming a sheet, or an injection molded tray. The deformation inside was limited, and it was thought that the fall and the outflow of the contents in the impact of the opening of the vapor venting portion could be avoided.

For example, in Patent Document 1,
A package having a tray and a sealing film for sealing the opening of the tray, the sealing film being a portion fused to the top surface of the tray so as to follow the outer shape of the tray There is an extended general part, and a steaming scheduled part for releasing the steam inside the tray to the outside,
The steaming scheduled portion is a mountain-shaped portion in which the inner edge is formed so as to protrude toward the opening side with respect to the inner edge of the general portion, thereby forming a tip that is a pointed portion at the inner edge. Yes, a portion constituting one side with respect to the tip of the inner edge of the scheduled steaming portion, and a portion constituting the other side with respect to the tip of the inner edge of the scheduled steaming portion Curved to approach each other,
By having a curved shape similar to the inner edge of the outer edge of the steaming scheduled portion, a tip that is a pointed portion at the outer edge is formed,
The portion between the tip of the outer edge and the tip of the inner edge of the scheduled steaming portion is a joining portion corresponding to the top of the mountain shape, and is more general than the joining portion of the scheduled steaming portion. The non-merging part, which is a part on the part side, proposes a packaging container whose width becomes narrower from the general part side toward the joining part.
An intersection of a first line segment passing through the tip of the inner edge and the tip of the outer edge and a second line segment extending from the inner edge of the general part so as to pass through the first line segment; The packaging container according to claim 1 is also proposed in which the distance from the tip of the outer edge is longer than the seal width of the general part.

However, in the case of the packaging container 1 including the rectangular tray 2 having a long side and a short side, as shown in FIG. As shown, the vicinity of the central steam vent 24 is greatly deformed particularly by the internal pressure.
This is because the distance between the steam vent 24 and the steam vent 24 facing each other is partly the shortest in the cross section formed by the seal portion of the container, and the steam vent from the container center 11 of the heating packaging container 1 This is because the distance to 24 is also the shortest locally.

  When the heating container is heated, the air pressure inside the container rises, and the contents of the container boil and fill with steam. At that time, due to water vapor or the like inside the heating packaging container, it tends to be deformed so as to have the maximum capacity in the dimensions of the container and the film in its cross section. Since the deformed shape having the maximum capacity is a sphere, only the cross-section connecting the opposing steam vents 24 is deformed, particularly if it is close to a spherical shape. Moreover, if the container greatly exceeds the glass transfer point by heating, it can be easily deformed.

  If the container is deformed to a shape close to a sphere, the container may fall down and the contents that have become hot may leak, and the sealing film 3 is difficult to open. Even after the sealing film 3 is opened, the shape is likely to be fixed in a deformed state of the container, which causes problems such as being difficult to leave in a stable state and taking out the contents.

In order to solve the above problem, as shown in FIG. 2, at least one steam vent 24 is provided on both sides of the long side of the outer shape of the fused part, each shifted from the center of the long side. The heating packaging container 1 was examined.
The packaging container 1 has a shape in which the sealing film 3 that seals the opening of the tray 2 swells when heated, and then the seal part in the vicinity of the steam release part 24 peels off, and air is released from the steam release part 24 together with the internal steam. maintain. However, when cooling is started after heating, the water vapor in the tray becomes water and is condensed. At this time, the pressure corresponding to the capacity of the escaped air causes the inside of the container to become a negative pressure. And if the water droplet of the vapor removal part 24 adhering at the time of heating closes the vapor removal part 24, the sealing film 3 and the tray 2 will closely_contact | adhere, the packaging container 1 will be sealed, and the inside of the tray 2 will generate a high negative pressure. When the inside of the packaging container 1 has a negative pressure, as shown in FIG. 2, the rising angle of the storage side wall 212 with respect to the bottom part 211 is greatly widened, the long side storage side wall 212 is bent, the center of the storage bottom part 211 is lifted, etc. Cause deformation. When cooling proceeds in this state, the tray 2 is fixed in a deformed state, the heated tray 2 remains in a deformed state, and the contents spill out when the sealing film 3 is opened. There was a problem such as not being able to.

Japanese Patent Laying-Open No. 2015-151142

  Therefore, even if the present invention is a packaging container comprising a rectangular tray having a long side and a short side, the packaging container is greatly deformed by internal pressure during heating, and the container does not fall down or the contents do not leak. Instead, it is an object of the present invention to obtain a heating packaging container that can maintain a stable shape without being deformed even after cooling.

The invention according to claim 1 of the present invention is
In a rectangular tray having an opening formed from a long side and a short side, and a packaging container having a sealing film for sealing the opening of the tray,
The tray has a fusion part where the sealing film is fused over the entire circumference of the opening of the tray, and a part of the fusion part has a vapor vent part for releasing the internal vapor,
The steam vent has at least one place on each side shifted from the center of the long side with respect to the long side of the fusion part outer shape,
A heating packaging container having a tray sheet thickness of 0.6 mm or less.

  Even if the packaging container for heating of the present invention is cooled after heating, the shape does not change greatly, the container does not fall down, and the contents do not leak. It can be used as a container after being heated and cooled.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing a first embodiment of a heating packaging container according to the present invention, an enlarged view in the vicinity of a steam vent, and a view showing a state where the steam is peeled off at the steam vent. It is the top view which shows the state cooled after heating the packaging container for heating, and its longitudinal cross-sectional view. It is the top view in the normal temperature before the high frequency heating with the packaging container for heating which concerns on a prior art, and its longitudinal cross-sectional view. In the example of the packaging container for heating which concerns on a prior art, it is the top view which shows the state at the time of high frequency heating, and a longitudinal cross-sectional view. It is the top view which shows 2nd Example of the packaging container for heating which concerns on this invention, the enlarged view of the vicinity of a steam venting part, and the figure which shows the state which peels and vapor-deposits in the steam venting part.

Embodiments of the heating packaging container of the present invention will be described below with reference to the drawings.
1-1 is a plan view showing a first embodiment of the heating packaging container 1 according to the present invention, and FIG. 1-2 is a partially enlarged view in the vicinity of the vapor venting portion.
The heating packaging container 1 is composed of a tray 2 and a sealing film.
The tray 2 is fused to the sealing film around the storage portion 21 that stores the contents in a hollow having a rectangular shape formed from a long side and a short side at the center, and the opening 23 that is the upper end surface of the storage portion 21. And a flange 22.

  The storage portion 21 is formed only on the lower side from the inner edge of the flange 22, and includes a storage bottom portion 211 and a storage side wall 212. A rib 213 having a protruding shape is formed on the inner side from the storage side wall 212 to the vicinity of the storage bottom portion 211. It does not matter if it is provided.

  The flange 22 extends outward from the periphery of the opening 23, which is the upper end of the storage portion 21, and is fused on the entire periphery of the sealing film and the opening 23 to enable the heating packaging container 1 to be sealed.

  The fused portion 221 between the flange 22 and the sealing film is fused between the inner fused wire 2211 and the outer fused wire 2212. The inner fusion line 2211 is formed at a position that is substantially constant away from the periphery of the opening 23, but the fusion part 221 of the vapor vent 24 is closer to the opening 23 than the surrounding inner fusion line 2211. I have entered the position.

  The steam vent 24 in the first embodiment is in the fusion part around the opening, and has one place on both sides shifted from the center of the long side with respect to the long side of the outer shape of the fusion part. The container as a whole has four steam vents 24.

As shown in FIG. 1C, the steam vent 24 has a long side of the outer shape of the fused part, and the outer fused line 2212 outside the steam vented part is not the steam vent 24. The shape of the fusion part which entered inside with respect to the extended line position of the inner side fusion line 2211 of both sides is made.
For this reason, when the heating packaging container 1 is heated and the internal pressure increases, a large load is applied to the inner fused wire 2211 which is the inner end of the fused portion 221 closest to the center.
In the inner fusion wire 2211 and the outer fusion wire 2212, the sealant is once melted and solidified, and therefore has a significantly higher fusion strength than the fusion strength of the fusion part between them. In the heating packaging container 1 of the present invention, the pressure is most applied to the central part of the long side of the outer shape of the fused part 221. However, there is no steam vent 24 at the center of the long side, and the inner fusion line 2211 is fused in a straight line perpendicular to the opening direction, so the fusion strength at the center of the long side is high. Can withstand without opening.

  The pressure of the heating packaging container further rises, and a large internal pressure is applied to the inner fused wire 2211. At this time, the inner end 241 of the steam release portion 24 that protrudes inward by the inner fusion line 2211 is fused at a single point in the opening direction, and can withstand the increase in internal pressure. Can not. For this reason, the inner end 241 of the vapor releasing part 24 is peeled first with respect to the internal pressure, and the peeling of the sealing film starts. Further, the fusion part 221 following the inner leading end 241 of the vapor releasing part 24 is peeled off. Is done.

By the way, the outer fusion line 2212 of the steam release fusion part 221 of the present invention has a fusion part 221 that has entered inside with respect to the inner fusion line 2211 inside the other fusion part.
Therefore, before the peeling 240 reaches the extension line position 2210 of the inner fusion line 2211 on both sides of the steam release part 24 which is remarkably high and difficult to peel off, the peeling in the steam release part 24 is brought to the outer fusion line 2212. As a result, the inside of the heating packaging container 1 communicates with the outside, and the steam can escape. (Figs. 1-4)
In the first embodiment of FIG. 1, the steam vent 24 has a distance B between the inner end 241 of the steam vent 24 and the container center 11, and a distance A between the center of the long side inside the fused part and the container center 11. It is arranged at a position that is not close to and sufficiently far away.
Even when the internal pressure increases, the heating packaging container 1 is subjected to the most peeling pressure at the long side center part of the outer shape of the fused part 221 near the container center 11, but the long side center part is in the opening direction. In addition, since they are fused in a straight line, the strength of the fusion at the center of the long side is high, and it is possible to withstand the increase in internal pressure without opening.
For this reason, the packaging container 1 for a heating can maintain a shape, without carrying out a big deformation | transformation.
When the internal pressure further increases, the fused portion 221 of the inner end portion 241 of the steam vent 24 is peeled off, and the steam generated inside the container passes through the groove 242 outside the steam vent 24.
At this time, since the steam is only partially removed, the heating packaging container 1 can maintain a high temperature and a high pressure for a certain period of time, and the contents can be cooked during this time.

FIG. 5 is a plan view showing a second embodiment of the heating packaging container 1 according to the present invention, an enlarged view in the vicinity of the steam vent 24, and a diagram showing a state where the steam vent 24 is peeled off and steam is vented. It is.
In the second embodiment, the steam vents 24 are arranged at four locations, one at each end of the long side of the fused portion outer shape.
For this reason, the steam vent 24 has the farthest distance B between the inner tip 241 of the steam vent 24 and the container center 11 with respect to the distance A between the center of the long side inside the fused part and the container center 11. The distance B is surely disposed at a position farther than the distance A.
In addition, since the steam release part 24 is provided in the long side edge part, in this 2nd Example, the extension line position 2210 becomes a curve, and the outer side fusion | melting line 2212 only in the steam release part 24 vicinity is an extension line position. It turns out that it has entered into the inner part by LA dimension than 2210.

  The base layer of the sealing film used in the sealing film of the present invention includes a polyethylene terephthalate film, a biaxially stretched polyamide film, a polyvinylidene-coated extruded polyamide film, a polyamide / metaxylenediamine / polyamide coextruded film, and a biaxially stretched polypropylene film. , Etc. There is no particular limitation as long as it has mechanical strength and dimensional stability. A biaxially stretched film is particularly preferable. Moreover, what provided the metal oxide vapor deposition layer, such as a silicon oxide, in these films may be used.

Moreover, the base material layer of a sealing film can be suitably provided with a printing layer as needed. The printed layer is a layer printed with an ink obtained by adding various pigments, extender pigments, plasticizers, drying agents, stabilizers and the like to a binder resin such as urethane, acrylic, nitrocellulose, or rubber. As the printing method, known printing methods such as gravure printing, silk screen printing, and ink jet printing can be used. Moreover, the adhesiveness of a printing layer can be improved by performing the corona treatment or the ozone treatment on the surface of a base material layer as a pretreatment beforehand.
In addition to displaying the contents, the printing can also improve the quality by indicating the position where the coating position alignment of the low seal layer used when making the pillow container is accurately aligned.

  The sealant layer used for the sealing film is required to be compatible with safety, tasteless and odorless, heat resistance, sealing property, sealing strength, puncture, pressure resistance, and the like. For example, an unstretched polypropylene film for retort, a coextruded polypropylene, a polyamide / polypropylene coextruded film, and the like can be considered.

  Moreover, as a sheet | seat used for a tray, the sheet | seat containing a filler etc. which knead | mixed the filler etc. in those resins can be considered, such as a polypropylene sheet, a polyethylene terephthalate sheet.

  Examples of the present invention will be described below.

<Example 1>
As a molding material for the tray, a polypropylene sheet containing a 0.55 mm filler was used, and the tray was molded into a shape of FIG. 1 with a length of 150 mm, a width of 200 mm, and a depth of 60 mm.
As the sealing film, a biaxially stretched heat-fixed polyethylene terephthalate (thickness 12 μm) / adhesive / easy peel sealant (thickness 30 μm) film was used. Immediately before the sealing film was bonded, the polyethylene terephthalate film was subjected to corona discharge treatment, and a two-component curable urethane adhesive was bonded by a dry laminating machine.
The contents were filled with 300 g of frozen pasta, and the seal shape was provided with steam vents at a total of 4 locations, 2 locations each 50 mm apart from the center of the long side. (Tray with L in Fig. 1-1 set to 100 mm)

<Example 2>
A 0.60 mm filled polypropylene sheet was used as a molding material for the tray, and other conditions were adjusted to those in Example 1.

<Comparative Example 1>
A 0.70 mm filled polypropylene sheet was used as a molding material for the tray, and other conditions were adjusted to those in Example 1.

<Comparative Example 2>
A 0.65 mm filled polypropylene sheet was used as a molding material for the tray, and other conditions were adjusted to those in Example 1.

<Example 3>
As a tray molding material, a polypropylene sheet containing a filler of 0.55 mm was used, and the tray was manufactured by molding into a shape of FIG. 5 with a length of 150 mm, a width of 200 mm, and a depth of 60 mm. (The seal shape was provided with steam vents at the four corners.) The other conditions were the same as in Example 1.

<Example 4>
A 0.60 mm filled polypropylene sheet was used as a molding material for the tray, and other conditions were adjusted to those in Example 3.

<Comparative Example 3>
A 0.70 mm filled polypropylene sheet was used as a molding material for the tray, and other conditions were adjusted to those in Example 3.

<Comparative example 4>
A 0.65 mm filled polypropylene sheet was used as a molding material for the tray, and other conditions were adjusted to those in Example 3.

<Evaluation method>
<Fumigation time> After putting each heating packaging container into a -10 ° C freezer for 48 hours, take it out from the freezer, leave it at 20 ° C for 5 minutes, and then put it into a 600W microwave oven to release steam. The time from when the part was opened until the vapor inside the container was ejected was measured.
<Fumigation state> After heating, after steam is spouted, is the packaging container for heating collapsed or the contents spouted during the steaming time from when the steam vent is opened and the steam inside the container is spouted? Was observed. <Deformation of container> After steaming, the container was cooled and decompressed, and allowed to stand for 10 minutes or more, and then the presence or absence of deformation of the heating packaging container was observed.

<Evaluation results>
<Fumigation time> In any container, the vaporization started at 3 minutes and 16 seconds to 3 minutes 53 seconds.
<Fumigation state> The packaging container for heating did not fall down or the contents did not blow out during the vaporization.
<Deformation of container> In the examples, there was no major deformation, no sealing film was peeled off stably, and it was difficult to place on the table or the contents spilled out.
However, in the comparative example, the storage side wall of the heating packaging container is greatly bent or the angle between the storage bottom and the storage side wall is widened, and the deformed state is fixed after opening and the contents spill out. A problem such as occurred.

  <Influence of tray thickness> In the tray having a thickness of 0.60 mm or less, there was no influence between the steam vents, and problems such as deformation of the container did not occur. Deformation of the container due to decompression after steaming occurred.

  From the above results, the packaging container for heating according to the present invention is arranged at a position where the steam vent is separated from the center of the long side to the left and right even if the sealing surface has a shape such as a rectangle with a large vertical and horizontal ratio. In addition, the container is a good container that does not generate deformation due to reduced pressure after heating, simply by making the thickness of the original fabric 0.60 mm or less. In addition, it is a heating packaging container that can be easily peeled and unsealed and smoothly discharged water vapor when the internal pressure rises to a certain value without using special materials or machines. Since it can be manufactured using equipment, the price can be easily reduced, and the merit of the present invention is great.

1 ... Packaging container for heating 11 ... Container center 2 ... Tray 21 ... Storage part 211 ... Storage bottom 212... Storage side wall 213... Rib 22... Flange 221. Extension line)
2211... Inner fusion wire 2212... Outer fusion wire 23... Opening 24.・ ・ ・ ・ ・ ・ Inner tip (steam vent)
242 ... ・ Groove (outside of steam vent)
3 ... Sealing film A ... Long distance center-container center distance B ... Steam outlet inside tip-container center distance

Claims (4)

In a rectangular tray having an opening formed from a long side and a short side, and a packaging container having a sealing film for sealing the opening of the tray,
The tray has a fusion part where the sealing film is fused over the entire circumference of the opening of the tray, and a part of the fusion part has a vapor vent part for releasing the internal vapor,
The steam vent has at least one place on each side shifted from the center of the long side with respect to the long side of the fusion part outer shape,
A heating packaging container having a tray sheet thickness of 0.6 mm or less.   The steam release part is the shape of the fusion part in which the outer fusion line of the steam release fusion part enters the inner side of the inner fusion line inside the other fusion part at the long side of the outer shape of the fusion part. The heating packaging container according to claim 1, wherein   2. The steam vent has a position where the distance between the inner end of the steam vent and the container center is not close to the distance between the center of the long side inside the fused part and the container center. Or the packaging container for a heating of 2.   The packaging container for heating according to any one of claims 1 to 3, wherein a plurality of grooves leading to the outside are provided on the surface of the tray outside the steam vent.

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