JP2002145353A - Easy-opening type sealed container for frozen food - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a pressure in a container from being increased with gaseous substances generated under heating operation when an easy-opening sealed container having a frozen food stored therein is melted or cooked in a microwave oven, prevent the sealed container from being ruptured and realize a smooth gas removing operation. SOLUTION: There is provided an easy-opening type sealed packaging container for a frozen food in which the innermost layer at its peripheral part is melted and adhered with heat and an easy-opening material held in at least a part of the heat melted segment is applied for a weak seal characterized in that a location near the central part of the easy-opening type sealing member is provided with at least one slit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of heating, thawing and cooking frozen foods contained in an easily-openable sealed container after heating and decompressing and cooking the frozen foods, by increasing the internal pressure of the container due to the gas generated from the frozen foods accompanying the heating. The present invention relates to a mechanism for smoothly releasing gas when a bag is broken.

[0002]

2. Description of the Related Art Various methods have been devised on how to smoothly degas a sealed cooking bag for a microwave oven without a loud popping sound during cooking. In order to maintain easy openness, seal strength should be 1.0 to
It is necessary to keep it at around 1.5kg / 15mm. On the other hand, for containers to be subjected to retort heat treatment, Notification No. 17 of the Ministry of Health and Welfare stipulates that "in containers and packaging of pressurized and heat-sterilized food packed in containers and packaging, the heat sealing strength must be 2.3 kg / 15 mm or more". . However, packaging containers for storing frozen foods do not have such a rule.

[0003] The mechanism for easy opening of the easy opening container differs depending on the site and material used. When peeling off the heat-sealed lid material for the retort type and the container, there is an example in which a compound obtained by blending polypropylene high-density polyethylene or the like and forming a compound is used as the lid material. On the other hand, in the pouch type, the innermost layer of the laminated packaging material forming the pouch is heat-welded, and the easy-opening material is sandwiched between the heat-welded portions. Also in this case, the easy-opening packaging material is used by blending the same resin as the heat-sealed innermost layer material and the resin which is hardly heat-sealed.

There is a technique in which a sealed packaging bag for a microwave oven containing food is prevented from being broken when the microwave oven is heated, and a gas (main component: steam) filled in the bag is quickly discharged to the outside of the bag. In Utility Model Registration No. 2525918, the width of the heat seal is partially narrower than others. Japanese Patent Application Laid-Open No. H10-95471 discloses that a part of a heat seal portion has a lower sealing strength than other portions, and a width of 1/4 to 3/4 of a heat seal width from an outer edge of the low heat seal portion toward an inside thereof. A non-seal part is formed. Japanese Patent Application Laid-Open No. H11-29181 relates to a sealed packaging bag for a microwave oven having a back pasting portion, in which a narrow sealing width is provided in a partial region of the back pasting portion, and an opening sealing portion which can be peeled open by the internal pressure of the packaging is provided. Utility model registration 30483
In No. 91, a punching hole was provided in the heat seal portion of the microwave oven bag, and the internal pressure was released from the punching hole. Japanese Utility Model Registration No. 3048825 discloses that a laminated packaging material is provided with a punched hole, and the laminated packaging material and the non-punched holed laminated packaging material are heat-sealed to form a microwave oven bag, and the internal pressure is released from the punched hole. ing. Japanese Patent Application No. 11-59747 discloses that when the internal pressure of a packaging bag becomes higher than a predetermined value due to heating, a cyclized rubber release layer from which a heat seal portion can be peeled open by the pressure.

[0005]

When an easily openable sealed container containing frozen food is thawed or cooked in a microwave oven, an internal pressure rises due to gas components generated by heating,
When the easily openable sealed container reaches the pressure limit, it is accompanied by a loud noise and sometimes bursts such that the contents pop out.
A problem to be solved by the present invention is to realize smooth gas venting while avoiding gas venting due to rupture.

[0006]

Means for Solving the Problems When the present inventor cooks an easily openable sealed container containing frozen food in a microwave oven,
By observing the phenomenon that the sealing surface of the weakly sealed portion of the easily-openable sealed container recedes as the internal pressure of the easily-openable sealed container approaches the limit of pressure resistance due to the increase in internal pressure due to the gas component generated by heating, When the retreat of the surface reaches the outer edge of the seal, a loud noise is generated, locating that the bag breaks, and the retreat of the seal surface is vented before reaching the outer edge of the seal to prevent rupture with a loud noise, more than necessary The present invention was found to prevent the spread of a severely broken portion and thereby suppress the protrusion of the contents, thereby completing the present invention. That is, the first aspect of the present invention is an easily-openable hermetically sealed packaging container having an innermost layer of a peripheral portion thermally welded and having a weakly-sealed portion made of an easily-openable material sandwiched between at least a part of the thermally welded portion. An easily openable sealed container for frozen foods having at least one notch near the center of the material sandwiching portion. The second aspect of the present invention is an I-notch and a V-notch having a notch having a width of at least 0.3 mm. , A U-notch, a concave notch or a punched hole, is an easily-openable sealed container for frozen food, the third of the present invention is that the sandwiched easy-opening material part is sandwiched around a flat pouch, a standing pouch top, and a back. An easily openable sealed container for frozen food is provided at each of the heat-sealed portions of the back sticking portion of the package having the sticking portion and the tail sticking portion of the package having the tail sticking portion. Sealed packaging containers are frozen A frozen food easily openable sealed container, which is used for goods, fifth is the frozen food easily openable sealed container of claims 1 to 4, wherein formed by housing a frozen food product of the present invention.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An easily openable hermetically sealed packaging container having an innermost layer of a peripheral portion used in the present invention and having a weak seal portion made of an easily openable material sandwiched between at least a part of the heat welded portion. Is a container that is widely used in general, and the easy-opening member is a material that utilizes the property that the heat-welding portion lowers the heat-welding strength by biting a foreign substance in the heat-welded portion. For example, if the heat welding material is polypropylene, a resin based on polypropylene and blended with high-density polyethylene may be used. In addition, the easy-opening member has a multilayer structure composed of a coating layer and a laminating film, and a type in which internal cohesive failure of the coating layer and the laminating film itself occurs to obtain easy-opening properties, and a layer between the constituting coating layer and the laminated film. Materials of a type that can be easily opened while peeling are also applicable.

The easy-open material portion of the easily-openable sealed packaging container is usually formed by sandwiching the easy-open material along one sealing surface of the container. In this case, if the container is polygonal, it may be the entire sealing surface on one side or may be partial as long as gas can be smoothly vented. When there is no side such as a circle or an ellipse, a part of the sealing surface satisfying the above conditions is sufficient.

[0009] The seal vertical width in the center direction of the easily-openable sealed packaging container from the outer periphery of the weak seal portion of the easily-openable sealed packaging container is usually preferably 8 to 20 mm. 1
If it is less than 0 mm, especially about 5 to 7 mm, it will not be able to maintain a sealed state by peeling during transportation or handling, and the risk of impairing the packaging function will increase. In addition, since the sealing area is small, the easy-opening member is easily peeled at the time of gas release, resulting in an unnecessarily large gas release port, which increases the risk of rupture of the contents, which may be scattered or jumped out. On the other hand, if the seal width exceeds 20 mm, the time required to start peeling and degas out becomes longer, and the gas generated inside the sealed container increases, causing the pressure inside the container to rise excessively and causing rupture with loud noise. More likely to happen. In addition, an increase in the use area of the easy-opening member results in an increase in the price of the container and an economic disadvantage.

It is important that the notch has a notch area. Therefore, an I-notch that does not have a cut-out notch is not practical because smooth gas release is not performed even if the retreat of the sealing surface that occurs during microwave heating reaches the end of the I-notch. A second aspect of the present invention is that the notch has a notch having a width of at least 0.3 mm,
It is an easily openable sealed container for frozen foods, which is a notch, a concave notch or a punched hole. For smooth degassing, a width of 0.3 mm or more is required for an I notch, preferably 0.5 mm or more, and more preferably 1 mm. The V-notch, U-notch, and concave notch also have notched areas, so that even if a complete punched hole is formed in the notch surface, a smooth gas is generated when the retreat of the sealing surface reaches the punched hole edge. Drilling is performed.

[0011] Due to an increase in internal pressure due to a gas component generated by heating the easily-openable sealed container containing the frozen food in a microwave oven, as the easily-openable sealed container approaches the limit of the pressure resistance, the seal retreats. . Seal retreat is equal to the seal surface where the weak seal has been removed. The seal retreat occurs from the inner end of the seal in the easily-openable sealed container to the outer edge of the weak seal portion, and its shape is the seal length in the long axis direction of the seal surface as the bottom side, and the seal extends from the inner end of the seal to the outer edge. It has a generally triangular shape whose height is the distance at which the surface is cut open. The area near the vertex has a round shape. Therefore, the seal retreat line is not straight, but forms a convex curve toward the outer end. When the convex end of the seal retreat reaches the notch end, degassing is started.

The notch is preferably provided at the center of the seal retreat line where the retreat of the seal proceeds most deeply. A plurality of notches may be provided. It can also be provided on the central cutout and on both sides. In this case, the notch depth (length) on both sides
If the is deeper than the central notch, the seal receding line will contact the notch at multiple points, allowing for smoother venting.

[0013] When the back pasting portion provided on the easy-opening sealed container storing the frozen food is moved to the left or right and provided at the end of the container, a sealed container having a tail pasting portion where the end of the container (pouch) is bifurcated. Become. A weak seal portion made of an easily-openable material may be provided on the back sticking portion or the tail sticking portion.

[0014]

[Test method] Test 1) Gas release sound: The size of the sound when gas was released when the sealed container was broken during microwave cooking was observed by ear and evaluated on a three-point scale. A No sound, B Slightly small sound, C Loud sound Test 2) Breaking width: The size of the opening of the gas escape opening in the weak seal portion at the time of gas escape and the tearing width (mm) were measured. A less than 10mm, B 10-20mm, C more than 20mm

[0015]

[Embodiments 1 to 10] A weak seal portion (length
Sealed container (4-sided seal pouch, horizontal length 13) with tail sticking part having 130mm X width 11mm, seal strength about 1.0kg / 15mm
0mm, length 170mm, tail paste width 30mm, body material configuration ONY2
5 μm / DL / CPP 50 μm) was filled with food (content 100 g), and a frozen sample was provided with a cutout in the tail paste portion as shown below. Microwave oven (Matsushita Electric Industrial, NE-S22
The test items were evaluated for degassing behavior when heated with a mold and rated output of 600 W). The results are shown in Table 1. Notch width (mm): When the notch is provided from the outer edge of the weak seal portion, it is represented by the width along the outer edge, or in the case of a punched hole, by the diameter (mm). Notch depth (mm): Notch depth (length) from the outer edge of the notch toward the center of food storage). -Number of cutouts: In the case of one, it was installed in the center. In the case of two, it was provided at a position 0.5 mm left and right from the center, and in the case of three, it was provided at the center (depth 3 mm) and 0.7 mm left and right. Notch installation position (mm): Expressed as the distance from the deepest end of the notch depth to the inner end of the weak seal in contact with the food storage unit.

[0016]

[Table 1]

[0017]

Embodiments 11 to 18 Weak seal portions (length
130mm x 15mm width, flat pouch type sealed container with seal strength of about 1.0kg / 15mm (4-side sealed flat pouch, 130m in width)
m, length 170mm, body material composition ONY25μm / DL / CPP50μm)
A sample filled with food (content 100 g) and frozen was placed on a heat-sealed portion at one end of the flat pouch.
Some notches shown in FIG. The test items were evaluated for gas release behavior when heated with a microwave oven (Matsushita Electric Industrial, NE-S22, rated output 600 W). The results are shown in Table 2.

[0018]

[Table 2]

[0019]

COMPARATIVE EXAMPLE 1 The same conditions were used except that the sealed container of the example was not provided with a notch, and an I-notch having no notch width and a notch having a small depth of cut (2 mm) were provided. A comparative test of the closed container was performed. Table 3 shows the results
It was shown to.

[0020]

[Table 3]

The following summarizes the experimental results. 1 When the width of the notch was an I-notch of 0 mm, the outgassing behavior was almost the same as the control without the I-notch. When the width of the notch was widened to about 0.5 mm, the tendency for outgassing to be smooth was clearly observed. (2) When the position of the notch was provided at a position close to the center of the tail pasted part, a tendency for gas to escape more smoothly than in the comparative example was observed. Further, it was observed that the effect of the notch portion was less likely to be exhibited as the position of the notch portion was further away from the center of the tail stuck portion. 3 A tendency was observed that the gas escape became smoother as the depth of the notch was deeper. However, even if the depth of the notch was shallow (short), if the position of the notch was closer to the center of the tail pasted part, the behavior of outgassing tended to be smooth. However, when the length of the notch was 2 mm or less, it was observed that even when the notch was provided at the center, there was not much difference in the behavior of outgassing as compared with the control. When the number of the four notches was set to two, a tendency was observed that gas escape became smoother than that of the control. One to two notches
Compared with the case where the number of cutouts is small, the probability of smooth gas escape is increased by appropriately selecting the position, depth and the like of the notch.

[0022]

According to the present invention, in the easily-openable hermetically sealed container, the innermost layer of the peripheral portion is heat-sealed, and the weak-sealing portion is sandwiched by at least a part of the heat-welded portion. By having at least one notch near the center of the part, smooth degassing became possible.

Claims (5)

[Claims] 1. An easily-openable hermetically sealed container having an innermost layer in a peripheral portion thermally welded and having a weakly-sealed portion made of an easily-openable material sandwiched between at least a part of the heat-welded portion. An easily openable sealed container for frozen food, comprising at least one notch near the center. 2. The easily openable sealed container for frozen food according to claim 1, wherein the notch is an I notch, a V notch, a U notch, a concave notch or a punched hole having a width of at least 0.3 mm. 3. A backing portion of a packaging bag, wherein the weak seal portion has a peripheral portion of a flat pouch, an upper portion of a standing pouch, and a backing portion.
3. The easily openable sealed container for a frozen food according to claim 1, which is provided at each of the heat-welded portions of the tail sticking portion of the packaging bag having the tail sticking portion. 4. The easily openable sealed container for frozen foods according to claim 1, wherein the easily openable sealed packaging container is for frozen foods. 5. A frozen food product is stored therein.
An easily openable sealed container for frozen food according to the above.