JP2000085855A - Packaging bag for food - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging bag which can be heated with cooked food packaged inside and which does not damage the taste or quality of the food. SOLUTION: On a certain face of a bag formed of flexible synthetic resin films 1, 2, an outwardly folded part 4 is over its width direction. On one face of the folded part or on the bag body of the face with the folded part formed, a ventilation hole 5 communicating with the inside and outside of the bag is provided. By folding the folded part onto the body side of the bag, the ventilation hole is closed, and the space between the folded part and the bag body is adhered with an adhesive 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bag for packaging cooked foods such as frozen foods, and more particularly, to a food packaging bag which can be heated by a microwave oven or the like while the foods are packed.

[0002]

[Prior art and its problems] Prepared foods include frozen foods,
There are various foods such as chilled foods and retort foods, all of which are heated before eating.

[0003] Cooked foods are often heated in a microwave oven, but if the packaged cooked foods are directly heated in a microwave oven, the packaging bag is sealed so that the quality of the food does not deteriorate. The pressure inside the packaging bag increases due to a large amount of water vapor generated from the food due to the heating, and the packaging bag may burst and the food may be scattered.

[0004] On the other hand, if the packaging bag is broken and heated, the packaging bag will not be ruptured. However, with the heating, the moisture of the food escapes, and the taste and quality of the food are dried and become dry or hard. May decrease.

Therefore, the cooked food is transferred to a heat-resistant dish or the like, covered with a wrap or the like, and then heated by a microwave oven, but it is complicated.

[0006]

It is an object of the present invention to provide a packaging bag which can heat cooked food in a packaged state without losing the taste and quality of the cooked food. It is in.

[0007]

In order to achieve the above object, a food packaging bag according to the present invention is provided on a certain surface of a bag made of a synthetic resin film having flexibility, and a mountain fold extending in the width direction of the bag. A bent portion is formed, and a vent hole communicating with the inside and outside of the bag is opened in the body of the bag on one side of the bent portion or on the surface on which the bent portion is formed, and the bent portion is directed to the body side of the bag. The air hole is closed by folding, and the space between the bent portion and the body of the bag is bonded.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a food packaging bag according to the present invention. FIG. 1 shows a first embodiment of the present invention, in which reference numeral 1 denotes a front side film, 2 denotes a back side film, and 3 denotes a heat seal portion.

The front and back side films 1 and 2 are made of a synthetic resin film having flexibility and heat sealing properties, such as polyethylene, polypropylene or polystyrene. A heat-resistant exterior material such as polypropylene, stretched nylon, polyester film, stretched polystyrene or paper is laminated to prevent the exterior material from melting during heat sealing. The illustration of the laminated state of the film is omitted.

The front side film 1 is formed with a mountain-folded portion 4 extending in the width direction of the bag, and on the bottom side of the bag (right side in the drawing) with respect to the bent portion 4 of the front-side film. ,
A vent hole 5 communicating with the inside of the bag is provided.

The bent portion 4 is located on the bottom side of the bag (right side in the figure).
The bent portion 4 is bonded to the front body of the bag with the vent hole 5 closed as shown in FIG.

As the adhesive, a resin-based adhesive soluble in a solvent is preferable. For example, vinyl acetate, polyamide stearate, vinyl chloride copolymer and the like are used. In addition, the code | symbol 6 in a figure shows the opening part of a bag, 7 is foodstuffs as contents, 8 shows the adhesive layer between the said bending part 4 and a front trunk | drum.

Next, the operation of the food packaging bag constructed as described above will be described with reference to FIGS. 3 (a) to 3 (c). Food 7
Is put in a packaging bag at a food processing factory or the like, and the opening 6 is closed by heat sealing or the like.

In the packaging bag before heating, as shown in the enlarged view of FIG. 3 (a), the back surface of the bent portion 4 closes the ventilation hole 5, the bag is sealed, and the outside air is introduced into the bag. There is no invasion of bacteria and germs, and the deterioration of food quality is prevented. In FIG. 2, the film before and after the bent portion 4 and the film before and after the bent portion 4 are in close contact with each other, but no bonding or heat sealing is performed between them.

When the food 7 is heated in the bag, since the bag is sealed as described above, the water vapor generated by the rise in the temperature of the food causes the pressure in the bag to increase. As shown in FIG. 3 (b), the space between the films before and after the bent portion 4 that has not been bonded or heat-sealed, and the space between the films 1 and 2 on the front and rear sides forming the bag are both spread.

When the pressure in the bag further rises, FIG.
As shown in FIG. 5, the bent portion 4 is peeled off from the front body portion against the adhesive force of the adhesive layer 8, the vent hole 5 is opened, and the water vapor in the bag is released from the vent hole to the outside and the inside of the bag is released. Pressure drops,
Rupture of the bag is prevented.

The pressure and temperature applied to the food can be set by appropriately selecting the adhesive strength and heat resistance of the adhesive used for the adhesive layer 8.

That is, it is possible to open the air hole with a low pressure by using an adhesive having a low adhesive strength, or to use an adhesive having a high adhesive strength to compare the inside of the bag. It is also possible to prevent the vent hole from opening unless the pressure becomes high.

It is also possible to use an adhesive having a low heat resistance so that the air holes can be opened even if the temperature does not become too high. If the temperature is not relatively high, the ventilation holes cannot be opened.

It is desirable to select the best adhesive strength and heat resistance depending on the material and size of the bag or the type, size (weight and volume) or shape of the food.

In the above-described first embodiment, a vent hole 5 communicating with the inside of the bag is formed on the bottom side (right side in the figure) of the bag with respect to the mountain-folded portion 4. The bag is folded toward the bottom (right side in the figure) of the bag. However, as in the second embodiment shown in FIG. 4, the ventilation hole 9 is located closer to the opening of the bag than the bent portion 10 (left side in the figure). The opening 10 may be folded toward the opening side of the bag (the right side in the figure) and adhered.

In the first and second embodiments, the bent portions 4 and 10 are formed in the width direction of the bag, however, they may be formed in the length direction. In the first and second embodiments described above, the ventilation holes 5 and 9 are provided in the front body, but the ventilation holes 4 and 10 may be provided on the side in contact with the front body. The number of ventilation holes may be provided at a plurality of places instead of one place.

[0023]

In the food packaging bag according to the present invention, before heating, the vent hole is closed by the bent portion and the bag is sealed, so that the outside air and various bacteria do not enter the bag. Food quality can be maintained.

When the pressure in the bag rises due to heating, the air holes are opened and the air (water vapor) in the bag is released to the outside,
The pressure in the bag is reduced, preventing the bag from bursting.

Therefore, it is possible to heat the food in the packaging bag without breaking the packaging bag or removing the food from the packaging bag.

Further, the food in the bag is steamed by steam generated from the food by heating, and is heated to a plump and moist and optimal state.

Further, by appropriately selecting an adhesive for bonding between the bent portion and the front body portion according to the bonding strength and heat resistance, the pressure and temperature in the bag in which the vent hole is opened can be freely adjusted. By setting the diameter and number of the ventilation holes as appropriate, the discharge speed of the air in the bag can be controlled, and the best heating can be performed according to the type and size of the food as the contents.

Further, since the adhesive is used between the bent portion and the front body, it does not touch the food as a content and has high safety to the human body.

[Brief description of the drawings]

FIG. 1 is a plan view showing a food packaging bag according to a first embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view taken along line II-II of FIG.

FIG. 3 is a partially enlarged longitudinal sectional view showing the operation of the food packaging bag according to the present invention.

FIG. 4 is a partially enlarged longitudinal sectional view of a food packaging bag according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front side film 2 Back side film 3 Heat seal part 4 Bend part 5 Vent hole 6 Opening of bag 7 Foodstuff as contents 8 Adhesive layer 9 Vent hole 10 Bent part

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E064 AA04 AA11 BA21 BB03 BC01 EA30 FA01 FA03 HD02 HE04 HU10 3E067 AB01 BA12A BB14A DA04 EA04 EA06 FA01 FC01 GB02

Claims (1)

[Claims] 1. A mountain-folded portion extending in the width direction of a bag is formed on a certain surface of a bag made of a synthetic resin film having flexibility, and one side or the bent portion of the bent portion is formed. A vent hole communicating with the inside and outside of the bag is opened in the body of the bag on the side of the bag, the bent portion is folded toward the body portion of the bag to close the vent hole, and the bent portion and the body of the bag are closed. Food packaging bag with a gap between them.