JP6926683B2 - Packaging container for heating - Google Patents

Description

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

In recent years, retort pouch foods have been stored in a pillow packaging bag with the sealant side of the plastic film aligned and the back seal and upper and lower edge edges heat-sealed, and a standing pouch, etc., and placed in the packaging bag with a microwave oven or the like. There is a packaging bag that heats as it is.
To heat such a packaging bag, the pillow packaging bag heats the steam venting back seal upward. In the standing pouch, the steam vent is processed in advance with the bottom facing down, and the steam vent is opened preferentially by heating, and when the internal pressure inside the packaging bag rises to a certain level, the inside of the pouch is inside. It is designed to remove steam and the like.
In the above packaging bag, the entire packaging bag swells in a spherical shape immediately before the vapor venting portion opens, and the entire packaging bag moves due to the impact of the opening of the vapor venting portion, and the liquid and fixed contents inside are scattered. Not only did it happen, but there were also problems such as the standing pouch falling over. For this reason, there was no choice but to heat the packaging bag in a large heat-resistant container.

Therefore, instead of a packaging bag, a packaging container made of a sealing film that can be sealed by fusing to the opening of the tray with respect to a tray in which a sheet is vacuum-molded or pressure-molded, an injection-molded tray, or the like is heated. The deformation inside was limited, and it was thought that the collapse and the outflow of the contents due to the impact of the opening of the steam vent 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, so that the sealing film is 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 planned steaming part for letting steam inside the tray escape to the outside.
The planned steaming portion is a mountain-shaped portion having a tip formed by a pointed portion on the inner edge of the general portion because the inner edge thereof is formed so as to protrude toward the opening side with respect to the inner edge of the general portion. There are a portion of the inner edge of the planned steaming portion that constitutes one side with respect to the tip, and a portion of the inner edge of the scheduled steaming portion that constitutes the other side of the tip. , Curved to approach each other,
Since the outer edge of the planned steaming portion has a curved shape similar to the inner edge, a tip which is a sharp portion is formed on the outer edge.
The portion of the planned steaming portion between the tip of the outer edge and the tip of the inner edge is a confluence portion corresponding to the top of the mountain shape, and is more general than the confluence portion of the scheduled steaming portion. We propose a packaging container in which the width of the non-merging portion, which is a portion on the portion side, becomes narrower from the general portion side toward the merging portion.
Further, 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 portion so as to pass through the first line segment. The packaging container according to claim 1, wherein the distance from the tip of the outer edge is longer than the seal width of the general portion is also proposed.

However, in the case of the packaging container 1 composed of the rectangular tray 2 having the long side and the short side as shown in FIG. 2, if the steam venting portion 24 is provided in the center of the long side portion, the steam venting portion 24 is provided in FIG. As shown, the vicinity of the central steam vent portion 24 is significantly deformed by the internal pressure.
This is because the distance between the steam venting portion 24 and the steam venting portion 24 facing each other is partially the shortest in the cross section formed by the seal portion of the container, and the steam venting portion is 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, the contents of the container boil, and the like, and the contents are filled with steam. At that time, due to water vapor or the like inside the packaging container for heating, it tries to be deformed so as to have the maximum capacity in the dimensions of the container and the film in the cross section. Since the deformed shape having the maximum capacity is a sphere, only the cross section connecting the steam venting portions 24 facing each other is deformed so as to be particularly close to the sphere shape. Moreover, if the container also greatly exceeds the glass transfer point by heating, it can be easily deformed.

If the container is deformed into a shape close to a sphere, the container may fall over and the hot contents may leak, and it is difficult to open the sealing film 3. Even after the sealing film 3 is opened, the shape of the container is likely to be fixed in a deformed state, so that it is difficult to leave the container in a stable state and it is difficult to take out the contents.

JP 2015-151142

Therefore, according to the present invention, even if the packaging container is composed of a rectangular tray having a long side and a short side, the packaging container is not significantly deformed by the internal pressure during heating, and the container is not tilted or the contents are not leaked. It is an object of the present invention to obtain a packaging container for use.

The invention according to claim 1 of the present invention
In a packaging container having a rectangular tray in which an opening is formed from a long side and a short side, and a sealing film that seals the opening of the tray.
The tray has a fusion portion in which the sealing film is fused over the entire circumference of the opening of the tray, and a part of the fusion portion has a steam venting portion for letting steam inside escape.
At least one steam venting portion is formed on each side of the long side of the outer shape of the fused portion, which is offset from the center of the long side.
The steam venting portion is characterized in that the distance between the inner end of the steam venting portion and the center of the container is not close to the distance between the center of the long side inside the fused portion and the center of the container. It is a packaging container for heating.

Since the shape of the packaging container for heating of the present invention does not change significantly even when heated, the container does not fall over and the contents do not leak. Therefore, the packaging container is put into a heating device such as a microwave oven as it is. And it can be heated.

It is a top view which shows the 1st Embodiment example of the packaging container for heating which concerns on this invention, the enlarged view of the vicinity of a steam vent part, and the figure which shows the state which peels off and steam is vented at the steam vent part. It is a plan view and the vertical sectional view at room temperature before high frequency heating in the packaging container for heating which concerns on the prior art. It is an example of the packaging container for heating which concerns on the prior art, and is a plan view and a vertical sectional view which show the state at the time of high frequency heating. It is a top view which shows the 2nd Embodiment example of the packaging container for heating which concerns on this invention, the enlarged view of the vicinity of a steam vent part, and the figure which shows the state which peels off and steam is vented at the steam vent part.

Hereinafter, embodiments of the packaging container for heating of the present invention will be described with reference to the drawings.
FIG. 1-1 is a plan view showing an example of the 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 steam venting portion.
The heating packaging container 1 is composed of a tray 2 and a sealing film.
The tray 2 is fused with the storage portion 21 for storing the contents by a rectangular recess formed from the long side and the short side in the center, and the sealing film around the opening 23 which is the upper end surface of the storage portion 21. It is formed of and from a flange 22.

The storage portion 21 is formed only on the lower side from the inner edge of the flange 22, and is composed of a storage bottom portion 211 and a storage side wall 212. It may be provided.

The flange 22 extends outward from the peripheral edge of the opening 23, which is the upper end of the storage portion 21, and is fused with the sealing film on the outside of the opening 23 all around, so that the packaging container 1 for heating can be sealed.

The fused portion 221 of 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 substantially constant away from the peripheral edge of the opening 23, but the fusion portion 221 of the steam vent portion 24 is closer to the opening 23 than the surrounding inner fusion wire 2211. It has entered the position.

The steam venting portion 24 in the first embodiment is located in the fused portion around the opening, and has one portion on each side of the fused portion outer shape with respect to the long side shifted from the center of the long side. The entire container has four steam vents 24.

As shown in FIG. 1-3, in the steam venting portion 24, on the long side of the outer shape of the fused portion, the outer fusion wire 2212 outside the steam venting fusion portion is not the steam venting portion 24. The shape of the fused portion is such that it enters the inside with respect to the extension line position of the inner fused wires 2211 on both sides.
Therefore, when the heating packaging container 1 is heated and the internal pressure rises, a large load is applied to the inner fusion wire 2211 which is the inner end of the fusion portion 221 at the position closest to the center.
In the inner fusion line 2211 and the outer fusion line 2212, since the sealant is a portion that has been once melted and solidified, it has a significantly higher fusion strength than the fusion strength of the fusion portion between them. In the packaging container 1 for heating of the present invention, the pressure is most applied to the central portion of the long side of the outer shape of the fused portion 221. However, since there is no steam venting portion 24 in the center of the long side and the inner fusion line 2211 is fused in a straight line perpendicular to the opening direction, the fusion strength of the center of the long side is high. , Can withstand without opening.

The pressure of the packaging container for heating further increases, and a large internal pressure is applied to the inner fusion line 2211. At this time, since the steam venting portion 24 inner tip portion 241 protruding inward by the inner fusion wire 2211 is only fused at one point in the opening direction, it can withstand an increase in internal pressure. Can not. Therefore, with respect to the internal pressure, the inner tip portion 241 of the steam venting portion 24 is peeled off first, the peeling of the sealing film is started, and further, the fused portion 221 following the inner tip portion 241 of the steam venting portion 24 is peeled off. Will be done.

By the way, the outer fusion line 2212 of the steam vent fusion section 221 of the present invention has a fusion section 221 that has entered inside with respect to the inner fusion line 2211 inside the other fusion section.
Therefore, before the peeling 240 reaches the extension line position 2210 of the inner fusion line 2211 on both sides of the steam venting portion 24, which has extremely high peeling strength and is difficult to peel off, the peeling is performed on the outer fusion line 2212 in the steam venting portion 24. Since it reaches, the inside of the heating packaging container 1 communicates with the outside, and steam can escape. (Fig. 1-4)
In the first embodiment of FIG. 1, in the steam venting portion 24, the distance B between the inner end portion 241 of the steam venting portion 24 and the container center 11 is the distance A between the center of the long side inside the fused portion and the container center 11. It is located far enough away from the vehicle.
In the packaging container 1 for heating, even if the internal pressure becomes high, the pressure of peeling is applied most to the center of the long side of the fused portion 221 outer shape close to the center 11 of the container, but the center of the long side is in the opening direction. Since it is fused vertically in a straight line, the strength of the fusion at the center of the long side is high, and it can withstand an increase in internal pressure without opening.
Therefore, the heating packaging container 1 can maintain its shape without being significantly deformed.
Further, when the internal pressure rises, the fused portion 221 of the inner end portion 241 of the steam venting portion 24 is peeled off, and the steam generated inside the container is released through the groove 242 on the outer side of the steam venting portion 24.
At this time, since the steam is only partially released, the heating packaging container 1 can maintain high temperature and high pressure for a certain period of time, and the contents can be cooked during this period.

FIG. 4 is a plan view showing an example of a second embodiment of the heating packaging container 1 according to the present invention, an enlarged view of the vicinity of the steam bleeding portion 24, and a view showing a state of peeling and steam bleeding at the steam bleeding portion 24. Is.
In this second embodiment, the steam venting portions 24 are located on both sides of the outer shape of the fused portion, which are offset from the center of the long sides, respectively. It is placed in a total of four locations, one near the center, not near both ends.
Even so, in the steam venting portion 24, the distance B between the tip portion 241 inside the steam venting portion 24 and the container center 11 is not close to the distance A between the center of the long side inside the fused portion and the container center 11. Although it is slightly smaller than that of the embodiment, the distance B is located farther than the distance A.
Since the steam venting portion 24 is provided in the middle of the long side, in this second embodiment, the extension line position 2210 is a straight line, and the outer fusion line 2212 is the extension line position 2210 only in the vicinity of the steam venting portion 24. It is easier to see that it is inside by the LA size.

As the base material layer of the sealing film used for the sealing film of the present invention, a polyethylene terephthalate film, a biaxially stretched polyamide film, a polyvinylidene coated extruded polyamide film, a polyamide / methixylylenediamine / polyamide coextruded film, and a biaxially stretched polypropylene film. , And so on. It is not particularly limited as long as it has mechanical strength and dimensional stability. A biaxially stretched film is particularly preferable. Further, these films may be provided with a metal oxide vapor deposition layer such as silicon oxide.

Further, a printing layer can be appropriately provided on the base material layer of the sealing film, if necessary. The printing layer is a layer printed with ink obtained by adding various pigments, extender pigments, plasticizers, desiccants, stabilizers, etc. to binder resins such as urethane-based, acrylic-based, nitrocellulose-based, and rubber-based. As the printing method, known printing methods such as gravure printing, silk screen printing, and inkjet printing can be used. Further, the adhesion of the printing layer can be improved by subjecting the surface of the base material layer to a corona treatment or an ozone treatment as a pretreatment in advance.
The quality of printing can also be improved by indicating the position where the coating alignment of the low seal layer used when making the pillow container is accurately aligned, in addition to the display of the contents.

The sealant layer used for the sealing film should be safe, tasteless and odorless. It is required that the strengths such as heat resistance, sealing property, sealing strength, piercing, and pressure resistance are suitable. For example, unstretched polypropylene film for retort, co-extruded polypropylene, polyamide / polypropylene co-extruded film, and the like can be considered.

Further, as the sheet used for the tray, a polypropylene sheet, a polyethylene terephthalate sheet, a sheet containing a filler or the like in the raw material of the sheet, or the like can be considered.

Examples of the present invention will be described below.

<Example 1>
A 0.7 mm filler-containing polypropylene sheet was used as a molding material for the tray, and the tray was molded into the shape shown in FIG. 4 at a length of 150 mm, a width of 200 mm, and a depth of 60 mm to manufacture a tray.
As the sealing film, a constituent film of polyethylene terephthalate (thickness 12 μm) / adhesive / easy peel sealant (thickness 30 μm) fixed by biaxial stretching heat was used. Immediately before the sealing film was bonded, the polyethylene terephthalate film was subjected to a corona discharge treatment, and the adhesive was a two-component curable urethane-based adhesive bonded by a dry laminating machine.
As the contents, 300 g of frozen pasta was put in, and the seal shape was provided with steam vents at two places 25 mm apart from the center of the long side, for a total of four places. (Tray with M in Fig. 4-1 set to 50 mm)

<Example 2>
A 0.7 mm filler-containing polypropylene sheet was used as a molding material for the tray, and the tray was molded into the shape shown in FIG. 1 at a length of 150 mm, a width of 200 mm, and a depth of 60 mm to manufacture a tray. As the sealing film, the same film as in Example 1 was used.
The contents were the same as in Example 1, 300 g of frozen pasta was put in, and the seal shape was provided with steam vents at two locations 50 mm apart from the center of the long side, for a total of four locations. (Tray with L in Fig. 1-1 of 100 mm)

<Comparison example>
A 0.7 mm filler-containing polypropylene sheet was used as a molding material for the tray, and the tray was molded into the shape shown in FIG. 2 at a length of 150 mm, a width of 200 mm, and a depth of 60 mm to manufacture a tray.
As the sealing film, the same film as in Example 1 was used.
As the contents, 300 g of frozen pasta, which is the same as in Example 1, was put in, and the seal shape was provided with steam vents at two places in total, one at the center of the long side.
rice field.

<Example 3>
A polypropylene sheet containing a filler of 0.55 mm was used as a molding material for the tray, and the tray was molded into the shape shown in FIG. 4 at a length of 150 mm, a width of 200 mm, and a depth of 60 mm to manufacture a tray.
As the sealing film, the same sealing film as in Example 1 was used.
As the contents, 300 g of frozen pasta was put in, and the seal shape was provided with steam vents at two places 25 mm apart from the center of the long side, for a total of four places.

<Example 4>
A polypropylene sheet containing a filler of 0.60 mm was used as a molding material for the tray, and the tray was molded into the shape shown in FIG. 4 at a length of 150 mm, a width of 200 mm, and a depth of 60 mm to manufacture a tray.
As the sealing film, the same sealing film as in Example 1 was used.
As the contents, 300 g of frozen pasta was put in, and the seal shape was provided with steam vents at two places 25 mm apart from the center of the long side, for a total of four places.

<Example 5>
A polypropylene sheet containing a 0.65 mm filler was used as the molding material for the tray.
A tray was produced by molding into the shape shown in FIG. 4 having a length of 150 mm, a width of 200 mm, and a depth of 60 mm.
As the sealing film, the same sealing film as in Example 1 was used.
As the contents, 300 g of frozen pasta was put in, and the seal shape was provided with steam vents at two places 25 mm apart from the center of the long side, for a total of four places.

<Example 6>
A polypropylene sheet containing a filler of 0.55 mm was used as a molding material for the tray, and the tray was molded into the shape shown in FIG. 1 at a length of 150 mm, a width of 200 mm, and a depth of 60 mm to manufacture a tray.
As the sealing film, the same sealing film as in Example 1 was used.
As the contents, 300 g of frozen pasta was put in, and the seal shape was provided with steam vents at two places 50 mm apart from the center of the long side, for a total of four places.

<Example 7>
A polypropylene sheet containing a filler of 0.60 mm was used as a molding material for the tray, and the tray was molded into the shape shown in FIG. 1 at a length of 150 mm, a width of 200 mm, and a depth of 60 mm to manufacture a tray.
As the sealing film, the same sealing film as in Example 1 was used.
As the contents, 300 g of frozen pasta was put in, and the seal shape was provided with steam vents at two places 50 mm apart from the center of the long side, for a total of four places.

<Example 8>
A polypropylene sheet containing a filler of 0.65 mm was used as a molding material for the tray, and the tray was molded into the shape shown in FIG. 1 at a length of 150 mm, a width of 200 mm, and a depth of 60 mm to manufacture a tray.
As the sealing film, the same sealing film as in Example 1 was used.
As the contents, 300 g of frozen pasta was put in, and the seal shape was provided with steam vents at two places 50 mm apart from the center of the long side, for a total of four places.

(Evaluation method)
<Steaming time> After putting each packaging container for heating in a freezer at -10 ° C for 48 hours, remove it from the freezer, leave it at room temperature at 20 ° C for 5 minutes, and then put it in a 600 W microwave oven to remove steam. The time until the part was opened and the steam inside the container was ejected was measured.
<Steaming state> During steaming, it was observed whether the packaging container for heating collapsed or the contents spouted out.
<Deformation of container> Whether or not the packaging container for heating was deformed during or after steaming was observed.

(Evaluation results)
<Steaming time> All containers were heated in the 3 minute range from 3 minutes 18 seconds to 3 minutes 55 seconds.
<Steaming state> During steaming, the heating packaging container did not fall over and the contents did not spurt out.
<Deformation of container> In the examples, there was no major deformation in any type, and the sealing film could be peeled off stably. However, in the comparative example, as shown in FIG. 3, the sealing film could not be peeled off cleanly due to a large bend at the center of the long side of the heating packaging container.

<Effect of tray thickness> When the original fabric thickness was 0.55 to 0.70 mm, there was no influence between the steam vents, and problems such as deformation of the container did not occur.

From the above results, the packaging container for heating of the present invention is simply arranged at a position where the steam vents are 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 having a large vertical and horizontal ratio. It is a good retort container that does not deform due to heating just by doing it, and when the internal pressure rises to a certain value without using special materials or machines, it easily peels off and opens, and the inside is smooth. It is a packaging container for heating that can discharge the steam of the above, and can be manufactured by using general-purpose equipment. Therefore, it is easy to keep the price down, 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 ・ ・ ・ ・ ・ ・ Fusion part 2210 ・ ・ ・ ・ ・ Extension line position (inner fusion) Extension of landing line)
2211 ・ ・ ・ ・ ・ Inner fusion wire 2212 ・ ・ ・ ・ ・ Outer fusion wire 23 ・ ・ ・ ・ ・ ・ ・ ・ Opening 24 ・ ・ ・ ・ ・ ・ ・ ・ Steam vent 240 ・ ・ ・ ・ ・ ・ Peeling 241・ ・ ・ ・ ・ ・ Inner tip (steam vent)
242 ... Groove (outside the steam vent)
3 ・ ・ ・ ・ ・ ・ ・ ・ Sealing film A ・ ・ ・ ・ ・ ・ ・ ・ Distance between the center of the long side and the center of the container B ・ ・ ・ ・ ・ ・ ・ ・ Distance between the tip inside the steam vent and the center of the container

Claims (3)

In a packaging container having a rectangular tray in which an opening is formed from a long side and a short side, and a sealing film that seals the opening of the tray.
The tray has a fusion portion in which the sealing film is fused over the entire circumference of the opening of the tray, and a part of the fusion portion has a steam venting portion for letting steam inside escape.
At least one steam venting portion is formed on each side of the long side of the outer shape of the fused portion, which is offset from the center of the long side.
The steam venting portion is characterized in that the distance between the inner end of the steam venting portion and the center of the container is not close to the distance between the center of the long side inside the fused portion and the center of the container. Packaging container for heating. The steam venting portion has a shape of a fused portion in which the outer fusion wire of the steam venting fusion portion enters the inside with respect to the inner fusion wire inside the other fused portion on the long side of the outer shape of the fused portion. The packaging container for heating according to claim 1, wherein the container is made of. The packaging container for heating according to claim 1 or 2, wherein a plurality of grooves leading to the outside are provided on the surface of the tray outside the steam venting portion.

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