JP3430331B2 - Laminated sheet - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated sheet, which is suitably used as a packaging material for foods in which steam or gas is generated after packaging. The laminated sheet of the present invention is particularly preferably used for packaging cooked rice, bread, confectionery and the like. Hereinafter, the conventional technique for packaging cooked rice will be mainly described, but the conventional technique is not limited thereto.

[0002]

2. Description of the Related Art Conventionally, in the rice food industry, etc., as a method of distributing cooked rice, rice is concentrated in large quantities at a rice center, and the cooked rice is packed in a warmer for transportation.
The method of delivering to each store is adopted.

[0003] As a transport warmer used at this time, a plastic container with a lid is generally used, and a container whose central portion is made of urethane foam resin is used to maintain the temperature. The cooked cooked rice was stored directly in this container or in a polyethylene bag or the like.

[0004]

However, a large amount of steam is generated in cooked rice after it is stored, and in a conventional transport warmer, steam generated from cooked rice is trapped in the heat insulation container. On the contrary, there is a problem that the cooked rice sticks to the cooked rice on the contrary and the cooked rice becomes sticky, and the cooked rice adheres to the inside of the heat insulation container and is difficult to take out. This was the same when the cooked rice was put in a polyethylene bag.

Particularly, when the cooked rice to be transported is sushi rice, there is a problem in that the vinegar component mixed in the sushi rice is scattered by the steam remaining in the container, so that the flavor is deteriorated.

As a solution to these problems, Japanese Utility Model Publication No. 6-30704 discloses a rice pack sheet having the following structure.

"A paper portion coated on one side with a heat-bondable resin film and a breathable and heat-bondable non-woven fabric portion, wherein the paper portion is formed from the surface coated with the resin film. A rice pack sheet having a large number of ventilation holes penetrating to the other surface side, wherein the resin film of the paper portion and the one surface side of the non-woven fabric portion are thermally bonded together. ”However, the rice having the above-mentioned configuration The pack sheet has vent holes,
Only the paper portion and the resin film were penetrated, and no vent hole was formed in the non-woven fabric portion.

[0008] The water content of rice normally used for cooking rice varies greatly depending on the harvest season and production area, and in particular, old rice has a low water content. It is necessary to adjust the amount of water during rice cooking depending on the water content of the rice, and rice with a low water content, especially old rice, requires a large amount of water during rice cooking. Since the amount of water used for cooking rice and the amount of water vapor generated from cooked cooked rice are approximately proportional to each other, the difference in steam generated from cooked cooked rice varies depending on the rice.

Since the rice pack sheet having the above-mentioned structure does not have vent holes formed in the non-woven fabric portion, it does not have sufficient air permeability, and when rice cooked rice that generates a large amount of steam is built in,
The built-in cooked rice could be sticky.

The rice pack sheet having the above structure is
Since the air holes are formed only in the paper part and the resin film, the manufacturing method is that after forming the resin film by applying the molten resin to the paper part, the air holes are formed, and then the paper part and the resin film are formed again. The film is heated to be heat-bonded to the nonwoven fabric, which requires a lot of steps.

In view of the above, the present invention is particularly suitable for use as a cooked rice warming bag for transporting cooked cooked rice and a food packaging bag for packaging bread, confectionery and the like. It is an object of the present invention to provide a laminated sheet which has good air permeability, is capable of absorbing permeated water vapor on its surface, and also has an appropriate moisture retention property.

[0012]

The present invention is to solve the above-mentioned problems by the following constitution.

(1) A laminated sheet in which a water-retaining layer having water absorption / moisture releasing property and a packaging surface layer are directly or indirectly heat-sealed to be laminated and integrated, and vapor without dew condensation. It is characterized in that a large number of ventilation holes are formed through the sheet body so as to ensure the emission.

Further, it is desirable that the packaging surface layer is formed of a long fiber non-woven fabric made of a thermoplastic resin because a laminated sheet excellent in heat retention can be obtained.

Further, if the two layers and the thermoplastic resin thin film are partially heat-sealed to form a large number of air pockets between the water retaining layer and the packaging surface layer, an air pool forming layer is interposed. In addition, the heat retention effect is increased, and the water absorption / moisture releasing effect is also increased, which is desirable.

Furthermore, if the packaging surface layer has a heat-sealing property, it can be easily formed when a bag is formed by using a laminated sheet such that the water retaining layer is arranged outside. ,desirable.

(2) Next, a method for manufacturing the laminated sheet having the above-mentioned structure will be described below.

At the same time as supplying the water retention layer forming film and the packaging surface layer forming film between the pressure bonding rolls, a laminating step of extruding a thermoplastic resin between the films and a material laminated sheet formed by the laminating step It is characterized in that it comprises a vent hole forming step of forming a large number of vent holes, and that one of the pressure-bonding rolls can be used as an uneven roll to form an air pocket forming layer between the water retaining layer and the packaging surface layer.

It is desirable that the ventilation holes be formed by passing the material laminated sheet between the needle roll and the brush roll because the formation of the ventilation holes is facilitated.

(3) Furthermore, it is possible to form a laminated sheet having a structure in which the packaging surface layer is formed of a thermoplastic resin thin film.

In the laminated sheet having the above structure, the packaging surface layer and the water retention layer are partially heat-sealed, and an air pool forming layer for forming a large number of air pools is interposed between the both layers. In this case, the heat retaining effect is increased and the moisturizing effect is also increased, which is desirable.

Further, if the packaging surface layer has a heat-sealing property, it can be easily formed when the bag is formed by using the laminated sheet so that the water retaining layer is arranged on the outside. desirable.

(4) Next, a method for manufacturing the laminated sheet having the above-mentioned structure will be described below.

Lamination in which a water retention layer forming film is supplied between pressure rolls and at the same time a thermoplastic resin is extruded
And a ventilation hole forming step of forming a large number of ventilation holes in the material laminated sheet formed in the laminating step, and one of the pressure bonding rolls is used as an uneven roll to form an air pool forming layer between the water retention layer and the packaging surface layer. Is capable of being formed.

Further, it is desirable that the ventilation holes are formed by passing the material laminated sheet between the needle roll and the brush roll, because the formation of the ventilation holes is facilitated.

By using the laminated sheet having the above structure,
It is also possible to form a cooked rice heat insulation bag or a food packaging bag by arranging the water retention layer on the outside.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

A. First, a laminated sheet that is an embodiment of the present invention will be described.

(1) As shown in FIG. 1, the laminated sheet 11 includes a water retaining layer 13 having a water absorbing / moisture releasing property and a packaging surface layer 15
Is a structure in which they are heat-sealed via a thermoplastic resin thin film 17 to be laminated and integrated, and between the water retention layer 13 and the thermoplastic resin thin film 17 and between the thermoplastic resin thin film 17 and the packaging surface layer 15. The air pool forming layers 19 that form a large number of air pools are respectively formed between them, and a large number of ventilation holes 22 are formed so as to penetrate the sheet body. The ventilation holes 22 have an inner diameter from the packaging surface layer 15 to the water retention layer 1.
It is formed to have a tapered cross-section, which becomes slightly smaller toward 3.

The water-retaining layer 13 has water-absorbing / moisture-releasing properties, and it is desirable that the water-retaining layer 13 has a function of absorbing water and releasing the contained water when the air dries, and the water-absorbing polymer capable of releasing the contained water. Processed into a sheet,
It is possible to use water absorbent paper, kraft paper and the like. Of these, water absorbent paper is preferably used. When water-absorbent paper is used, its basis weight varies depending on the food to be packaged, but is 15 to 80 g / m ² (preferably 20 to 6 g / m ² ).
Those of 5 g / m ² ) can be preferably used.

As the packaging surface layer 15, a non-woven fabric having a long fiber structure using a composite yarn using a polymer having two or more components such as a bimetal type (side-by-side type), a core-sheath type, a kidney type, and a matrix type. It is preferable to use since the fiber strength can be easily obtained. From the viewpoint of non-adhesiveness (non-adhesiveness) when the packaging surface layer 15 comes into contact with an object to be packaged, it is preferable that the surface thereof is usually formed of a nonpolar thermoplastic resin, such as polyethylene, polypropylene, It is preferably formed of a polyolefin such as polybutene, but it is also possible to use polar materials.

For parts other than the surface of the packaging surface layer 15, general-purpose thermoplastic resins usually used for synthetic fibers such as polyolefins such as polyethylene, polypropylene and polybutene, polyester (polyethylene terephthalate), styrene elastomer and polyamide are used. It is possible to It is also possible to use fibers made of a single polymer as the fibers forming the packaging surface layer 15.
However, if the whole is made of polyolefin, it is desirable to use a composite yarn in which at least a part of the surface is made of polyolefin, from the viewpoint of strength when molded into a bag or the like.

The nonwoven fabric used for the packaging surface layer 15 has a basis weight of 3 to 50 g / m ² (preferably 5 to 30 g / m ² ).
It is preferable to use the one having g / m ² ). Weight is 3
If it is less than g / m ^2, it is too thin to have poor heat retention and weak strength.

The thermoplastic resin thin film 17 is preferably made of a material having compatibility with the packaging surface layer 15, and is usually preferably made of a nonpolar thermoplastic resin. In the present embodiment, the thermoplastic resin thin film 17 is preferably made of polyolefin such as polyethylene or polypropylene. The thickness of the thermoplastic resin thin film 17 is desirably 3 to 20 μm (preferably 5 to 15 μm).

The ventilation hole 22 has an inner diameter of 0.1 to 2 mm on the packaging surface layer 15 side, although it depends on the food to be packaged.
(Preferably 0.2 to 1 mm, more preferably 0.3
To 0.8 mm) and at intervals of 3 to 20 mm (preferably 5 to 10 mm) and 6000 to ⁸ per 1 m ² .
0000 pieces (preferably 8000 to 40000 pieces) are formed, and the open area ratio is 0.1 with respect to the area of the laminated sheet 11.
It is preferably -15% (desirably 0.5-10%, more preferably 0.8-8.5%).

In this embodiment, as shown in FIG. 1, the ventilation hole 22 has a tapered cross-section whose inner diameter slightly decreases from the packaging surface layer 15 side toward the water retention layer 13 side. ing. The shape of the ventilation hole is not limited to this, and the shape of the air vent may be changed from the packaging surface layer 15 side to the water retention layer 13 side.
Of course, a shape having the same inner diameter up to the side can also be used. However, from the standpoint of obtaining good air permeability while maintaining a high water retention effect, it is preferable that the air holes have a tapered cross section.

Since the laminated sheet 11 of this embodiment has the above-mentioned structure, it has good air permeability and can absorb the permeated water vapor on its surface.
Therefore, even when it is formed into a bag and used in a closed container, the water vapor that has passed through the ventilation holes 22 and is discharged to the outside of the bag is absorbed by the water retaining layer 13 and is once discharged from the inside of the bag. The steam does not stay or adhere to the contents again, and the stickiness of the contents can be suppressed. Further, since the water retention layer 13 has an effect of releasing the contained water through the packaging surface layer 15 when the surroundings are dried, when the bag is used in a bag shape, the humidity inside the bag is always appropriate. It is kept in a state, and there is no danger that the contents will dry. Furthermore, since a non-woven fabric is used as the packaging surface layer 15, the heat retaining property is good, and when used in a heat retaining container, the heat retaining effect can be further improved.

Further, in this embodiment, the water retention layer 13
An air pool forming layer 19 that forms a large number of air pools is formed between the packaging surface layer 15 and the packaging surface layer 15. However, the present invention is not limited to this, and a structure that does not include the air pool forming layer 19 can also be used. is there. However, the formation of the air pool forming layer 19 is superior in heat retention, and if the air pool forming layer 19 is formed, the water vapor once discharged outside the bag through the ventilation hole 22. Is stored in the water retention layer 13 and at the same time, is temporarily stored in the air pool forming layer 19 and gradually releases water through the packaging surface layer 15 when the surroundings are dried, which is like a water reservoir. Since it also works, it excels in both water absorption and moisture release. Therefore, the air pocket forming layer 1
The one that formed 9 is superior in water absorption and moisture release,
It is desirable that the air pocket forming layer 19 be formed.

Further, in the present embodiment, the thermoplastic resin thin film 17 is provided between the water retention layer 13 and the packaging surface layer 15,
Although they are provided over the entire surface, the present invention is not limited to this, and they may be arranged in a band shape or randomly scattered, for example. When the thermoplastic resin thin film 17 is formed in this way, a portion where the thermoplastic resin thin film 17 is not arranged has the same action as the air pool forming layer 19, and in this case, the air pool forming layer 19 is formed.
Need not be formed.

It is also possible to directly adhere the packaging surface layer 15 to the water retaining layer 13 by heat fusion without interposing the thermoplastic resin thin film 17. However, when the thermoplastic resin thin film 17 is interposed, the air pocket forming layer 19 is provided both between the water retaining layer 13 and the thermoplastic resin thin film 17, and between the thermoplastic resin thin film 17 and the packaging surface layer 15. In addition, since it is formed in double, the heat retaining effect and the water absorption / moisture releasing effect are increased as compared with the case where the thermoplastic resin thin film 17 is not provided. Therefore, it is preferable that the thermoplastic resin thin film 17 is interposed.

(2) Next, a method for manufacturing the laminated sheet 11 of this embodiment will be described.

FIG. 2 is a schematic view showing an example of a method for manufacturing the laminated sheet 11. First, the water retention layer 13 is supplied from the water retention layer supply roll 23, and the thermoplastic resin thin film 1 is provided on one side thereof.
As 7, the molten thermoplastic resin is extruded from the T die 24 of the extrusion laminator and applied, and at the same time, the packaging surface layer 15 is retained from the packaging surface layer supply roll 25, and the thermoplastic resin thin film 17 is retained on the opposite side of the water retention layer 13. The layer 13 and the packaging surface layer 15 are supplied so as to be sandwiched, and then pressed by a cooling roll 26 and a rubber roll 28 whose surface is formed into a checkerboard-like unevenness, to form an air pool forming layer 19
At the same time as forming, the water retention layer 13 and the packaging surface layer 15 are adhered by heat fusion. After that, the ventilating hole 22 is formed by passing between the roll 29 with a needle and the brush roll 30 and piercing the roll 29 with a needle, and wound up on the laminated sheet winding roll 31 to obtain the laminated sheet 11 of the present embodiment. obtain.

When forming the vent hole 22, the position of the roll 29 with needles is fixed, and the brush roll 30 is pushed up from the water retaining layer 13 side to wrap the packaging surface layer 15.
The needle is pierced from the side to form the vent hole 22. The size and depth of the ventilation hole 22 can be easily adjusted by moving the brush roll 30.

In the above manufacturing method, the thermoplastic resin thin film 17 is formed on the entire surface, but a copper plate or the like is inserted into the lip of the T die 24 at an appropriate interval to forcibly cause curtain breaks and be arranged in a strip shape. It is also possible. in this case,
It is not necessary to form the air pocket forming layer 19, but it is also possible to form it.

The method of manufacturing the laminated sheet 11 of the present embodiment is not limited to the above-mentioned method. For example, the thermoplastic resin thin film 17 may be previously formed on the water retaining layer 13,
It is also possible to perform heat fusion with the packaging surface layer 15. Also,
The ventilation hole 22 is also formed in the same process as the sheet production in the above-described production method, but the invention is not limited to this, and it may be formed in another process after the sheet is produced, for example, by a punching machine. Is.

In the laminated sheet of this embodiment, since the ventilation holes are formed after the packaging surface layer and the water retaining layer are heat-sealed, the adhesive layer is applied to form the ventilation holes, and then the bonding is performed again as in the conventional case. There is no need to heat and heat bond the agent layer. Therefore, the number of man-hours does not increase, and the cost can be reduced as compared with the conventional method.

(3) Next, the rice cooked rice warming bag 32 formed by using the laminated sheet 11 of this embodiment will be described.

The cooked rice heat insulation bag 32 is formed so that the water retention layer 13 is on the outside, and FIG. 3 shows its usage. As a method of manufacturing the rice cooked rice warming bag 32, for example, the laminated sheet 11 is cut into a predetermined size,
The water retaining layer 13 is arranged on the outside so that the packaging surface layer 1
There may be mentioned a method of forming a bag shape by heat-sealing a part of 5 together.

Heat-insulating bag 3 for cooked rice thus manufactured
Into 2, use cooked rice, etc. Normally, in the case of white rice, cooked cooked rice is placed in a bag at a temperature of about 95 ° C. When this cooked rice is loaded into a bag and placed in a transport warmer, a large amount of steam is generated from the cooked rice. This water vapor passes through the ventilation hole 22 and is released to the outside. The released water vapor is absorbed in the water retaining layer 13, so that water is not retained and adheres to the cooked rice and the surface of the packaging surface layer 15 that comes into contact with the cooked rice. Therefore, it becomes possible to prevent the dew condensation of water. Therefore, the stickiness of the cooked rice is suppressed, the cooked rice does not adhere to the inside of the bag, and the rice can be transported in a good condition.

The water content of rice normally used for cooking rice varies greatly depending on the harvest season and the place of origin, and in particular, old rice has a low water content. It is necessary to adjust the amount of water during rice cooking depending on the water content of the rice, and rice with a low water content, especially old rice, requires a large amount of water during rice cooking. Since the amount of water used for cooking rice and the amount of steam generated from cooked rice are roughly proportional, the steam generated from cooked rice varies greatly depending on the rice, depending on the water content of the rice. It is preferable to appropriately change the number of ventilation holes 22 and the water retaining layer 13.

When used for sushi rice, since the sushi rice is put in the bag after seasoning, it is usually put in the bag at about 50 to 65 ° C. Therefore, water vapor is not generated rapidly but gradually. This generated water vapor is used for the vent 2
By releasing the vinegar component 2 through the outside, scattering of vinegar is suppressed, the flavor is not deteriorated, and the vinegar can be transported in a good condition.

In addition, the rice cooked rice warming bag 32 formed of the laminated sheet 11 of the present embodiment is excellent in heat retention since the packaging surface layer 15 is formed of non-woven fabric, and is put in a transport warmer. Even when it is stored by being stored, the heat retaining effect can be further improved.

In addition, the rice cooked rice warming bag 32 formed of the laminated sheet 11 of the present embodiment has a function of releasing the water contained therein when the water-retaining layer 13 is dried, and therefore, for example, for transportation. Even if you use it without putting it in a warmer and sealing it, the humidity inside the bag is always kept in an appropriate state,
The cooked rice will not dry out.

Therefore, the cooked rice warming bag 32 formed of the laminated sheet 11 of the present embodiment can release the steam generated from the cooked rice and keep the humidity of the cooked rice in an appropriate state. It plays the same role as the oak that has been used for the preservation of cooked rice since ancient times, and it is possible to prevent deterioration of the taste and yellowing of cooked rice.

In the present embodiment, the use of the laminated sheet 11 for cooked rice is illustrated, but the application of the laminated sheet 11 of the present embodiment is not limited to this, and freshly baked. It can also be used as a packaging material for foods that generate steam after processing such as bread, bean paste, roasted rice, fish meat products such as chikuwa, kamaboko, etc., and foods that generate ethylene gas such as vegetables. Since it has water absorbency, it can be used as a paper for fried foods and as a packaging material for fish and meat. Furthermore, by covering the freshly cooked rice in the rice cooker with the laminated sheet 11 of the present embodiment, since the rice has water-retaining property, the humidity of the cooked rice can be maintained in an appropriate state. The rice will not be too dry, and the deterioration of the taste can be prevented.

B. Next, a laminated sheet that is another embodiment of the present invention will be described.

(1) As shown in FIG. 4, the laminated sheet 21 has a structure in which the water retaining layer 13 having water absorbency and the packaging surface layer 27 are laminated and integrated by heat fusion. 1
3 and the packaging surface layer 27, an air pool forming layer 19 that forms a large number of air pools is formed, and a large number of ventilation holes 22 are formed so as to penetrate the water retaining layer 13 into the packaging surface layer 27. It is a formed structure.

The water retaining layer 13 can be made of the same material as in the above-mentioned embodiment, and it is preferable to use water absorbing paper as well. When a water-absorbent paper is used, its basis weight is 10 to 80 g / m ² (desirably 15 to 75 g / m ² , more preferably 20 to 65), although it varies depending on the food to be packaged.
g / m ² ) can be preferably used.

From the standpoint of non-adhesiveness (non-adhesiveness) when the packaging surface layer 27 comes into contact with the object to be packaged, it is usually preferable that the packaging surface layer 27 is formed of a non-polar thermoplastic resin, such as polyethylene, polypropylene or polybutene. It is preferably formed of a polyolefin such as, but it is also possible to use polar materials. The thickness of the packaging surface layer 27 is 3 to 2
It is desirable to set it to 0 μm (preferably 5 to 15 μm).

The ventilation hole 22 is preferably formed in the same manner as the laminated sheet of the above-mentioned embodiment, although it depends on the food to be packaged.

In this embodiment as well, the ventilation hole 22
As the laminated sheet of the above-described embodiment, a taper having a tapered cross-section whose inner diameter slightly narrows from the packaging surface layer 27 side toward the water retention layer 13 side is shown, but the invention is not limited to this. Of course, a shape having the same inner diameter can also be used. However, similarly to the laminated sheets of the above-described embodiments, from the viewpoint of obtaining good air permeability while maintaining a high water retention effect, it is preferable that the air holes 22 are formed in a tapered shape.

Since the laminated sheet 21 of this embodiment has the above-mentioned structure, it has good air permeability and can absorb the permeated water vapor on its surface.
Therefore, even when it is formed into a bag and used in a closed container, the water vapor that has passed through the ventilation holes 22 and is discharged to the outside of the bag is absorbed by the water retaining layer 13 and is once discharged from the inside of the bag. The steam does not stay or adhere to the contents again, and the stickiness of the contents can be suppressed. Further, since the water retention layer 13 has the function of releasing the water contained therein when the surroundings are dried, when the bag is used as a bag, the humidity inside the bag is always kept in an appropriate state, and the contents There is no danger of it becoming dry.

Further, in this embodiment, the water retention layer 13
Although the air pocket forming layer 19 is formed between the packaging surface layer 27 and the packaging surface layer 27, the present invention is not limited to this, and a sheet having no air pocket forming layer 19 may be used. However, also in the present embodiment, the air pocket forming layer 19 has the same effect as that of the above-described embodiment, so that the air pocket forming layer 19 is preferably formed.

(2) Next, a method for manufacturing the laminated sheet 21 of this embodiment will be described.

FIG. 5 is a schematic view showing an example of a method for manufacturing the laminated sheet 21. First, the water retention layer 13 is supplied from the water retention layer supply roll 23, and one surface of the water retention layer 13 is extruded from the T die 24 of the extrusion laminator and applied as a packaging surface layer 27. Then chill roll 2
6 and a rubber roll 2 whose surface is formed into a grid-like irregularity
8 and press to form the air pocket forming layer 19, and at the same time, the water retention layer 13 and the packaging surface layer 27 are fused by heat fusion. After that, the ventilating hole 22 is formed by passing the space between the roll 29 with needle and the brush roll 30 and piercing the roll 29 with needle to form the laminated sheet winding roll 4
The laminated sheet 21 of the present embodiment is obtained by winding the film on the sheet 1.

The cooling roll 26, the rubber roll 28,
The needle roll 29 and the brush roll 30 can be the same as those used in the production of the laminated sheet of the above-described embodiment, and the adjustment of the ventilation holes 22 is the same as in the production of the laminated sheet of the above-described embodiment. Do it.

Further, the manufacturing method of the laminated sheet 21 of the present embodiment is not limited to the above-mentioned method, and the manufacturing method of the ventilation holes 22 is not limited to the above-mentioned manufacturing method as in the above-described embodiments. Absent.

(3) Next, the food packaging bag 42 formed by using the laminated sheet 21 of this embodiment will be described.

The food packaging bag 42 is formed so that the water retention layer 13 is on the outside, and FIG. 6 shows an example of its usage. As a method for manufacturing the food packaging bag 42, for example, the laminated sheet 21 is cut into a predetermined size,
The water retaining layer 13 is arranged on the outside so that the packaging surface layer 2
A method of forming a bag shape by heat-sealing a part of 7 and the like can be mentioned.

The food packaging bag 42 manufactured in this manner
Then, add freshly baked bread and confectionery, and use. Hereinafter, description will be made by taking freshly baked bread as an example.

When freshly baked bread is placed in the food packaging bag 42 of the present embodiment and placed in the shipping container, the steam generated from the bread passes through the ventilation holes 22 and is discharged to the outside. Since the generated water vapor is absorbed in the water retention layer 13, there is no retention and adhesion of water on the bread and the surface of the packaging surface layer 27 that comes into contact with the bread, and it is possible to prevent dew condensation of water. Therefore, the stickiness of the bread is suppressed, and the bread can be transported in a good condition.

Further, in the food packaging bag 42 formed of the laminated sheet 21 of the present embodiment, the water retaining layer 13 has a function of releasing the water contained therein when the surroundings are dried,
The humidity inside the bag is always kept at an appropriate level, and problems such as drying of bread and hardening of the surface do not occur.

Further, if bread is put in the food packaging bag 21 of the present embodiment and transported, secondary contamination due to accumulated packaging,
It is also possible to prevent foreign matter from entering.

The application of the laminated sheet 21 of the present embodiment is not limited to bread and confectionery, but it can be used for various foods as in the above-mentioned embodiments.

[0075]

EXAMPLES The present invention will now be described in more detail based on examples.

<Example 1> 40 g / m 2 basis weight as a water retention layer
Using the ^second absorption paper, the core is a polyester as a packaging surface layer, core-in-sheath structure in which sheaths are formed of polyethylene, basis weight used of 15 g / m ² non-woven fabric. As a thermoplastic resin thin film between the water retaining layer and the packaging surface layer, T of the extrusion laminator is used.
10 μm of polyethylene melted at 320 ° C from the die
To form the air pocket forming layer by pressing with a rubber roll to form the air pool forming layer, and at the same time, the water retaining layer and the packaging surface layer are bonded by heat fusion. Next, a roll with a needle was used to form 40,000 ventilation holes having an inner diameter of 0.3 to 0.5 mm at intervals of 5 mm per 1 m ² to obtain a laminated sheet.

The laminated sheet produced as described above is
It was cut into a predetermined size, and the water-retaining layer was arranged on the outside so that the packaging surface layers were partially heat-bonded to each other to form a bag-like shape, thereby obtaining a cooked rice heat-insulating bag.

When the cooked rice cooked in this cooked rice warming bag is built into the warmer bag for transportation and transported, the stickyness of the cooked rice is suppressed and the cooked rice does not adhere to the bag. The handleability of cooked rice was also good. Also,
Even when used in sushi rice, the vinegar content was suppressed from scattering and the flavor was not deteriorated.

<Example 2> As a water retaining layer, a basis weight of 30 g / m
Using water absorbent paper No. ² , extruded polyethylene melted at 320 ° C as a packaging surface layer to a thickness of 8 μm from the T die of the extrusion laminator, and pressed it with a rubber roll to form an air pocket forming layer and at the same time retain water. The layers and the packaging surface layer are heat-sealed. Then, using a roller with a needle, vent holes having an inner diameter of 0.3 to 0.5 mm are formed at intervals of 5 mm.
A laminated sheet was obtained by forming 40000 pieces per 1 m ² .

The laminated sheet produced as described above is
It was cut into a predetermined size, and the water-retaining layer was placed on the outside so that parts of the packaging surface layers were heat-sealed to each other to form a bag-like shape, thereby obtaining a food packaging bag.

When freshly baked bread was built in this food packaging bag and packed in a shipping container for transportation, the bread was not sticky and was not too dry at the same time. Could be transported.

[0082]

The function and effect of the invention Since the laminated sheet of the present invention has the following structure, it has the following functions and effects.

A laminated sheet in which a water retention layer having water absorption / moisture releasing properties and a packaging surface layer are directly or indirectly heat-sealed to be laminated and integrated, and vapor diffusion without dew condensation is secured. Since it is a configuration in which a large number of ventilation holes that penetrate the sheet body are formed so that the ventilation is good, and
It is possible to absorb the permeated water vapor on its surface. Therefore, even when used in a bag-shaped closed container, the water vapor that has passed through the ventilation holes and discharged to the outside of the bag does not stay again or adhere to the object to be packaged, and Stickiness can be suppressed.
Also, the water-retaining layer has the effect of releasing the water contained in it when the surroundings are dry, so when using it in the form of a bag, the humidity inside the bag is always kept in an appropriate state and the contents do not dry. There is no danger of it coming out.

Further, if the packaging surface layer is made of a long fiber non-woven fabric made of a thermoplastic resin, the heat retaining property is good, and when used in a heat retaining container,
The heat retaining effect can be further improved.

Further, in the case where an air pool forming layer is formed between the water retaining layer and the packaging surface layer, the layers and the thermoplastic resin thin film are partially heat-sealed to form a large number of air pools. Has an excellent heat retaining property as compared with the case where the packaging surface layer is formed of a non-woven fabric, and when the air pocket forming layer is formed, it is once discharged to the outside of the bag through the ventilation hole. The water vapor is stored in the water retention layer and at the same time is temporarily stored in the air pool forming layer, and when the surrounding area dries, it also gradually releases water through the packaging surface layer, which also acts as a water reservoir. Because it plays, it also improves water absorption and moisture release.

Furthermore, when the packaging surface layer has a heat-sealing property, when a bag is formed by using a laminated sheet so that the water retaining layer is arranged on the outside,
It can be easily formed.

Further, the laminated sheet of the present invention has the vent holes formed after the packaging surface layer and the water retaining layer are heat-sealed, so that the man-hours do not increase and can be manufactured at low cost.

Furthermore, using this laminated sheet,
The rice cooked rice warming bag formed with the water retention layer arranged on the outside has excellent breathability, and the water vapor released to the outside of the bag is absorbed by the water retention layer, so cooked rice cooked The stickiness of cooked rice is suppressed even if it is built-in, packed in a transport warmer and sealed. Therefore, the cooked rice does not adhere to the bag and the handleability is good. In the past, when sushi rice, which had been spoiled due to water vapor remaining inside the container during transportation and had a poor flavor, was used for this cooked rice heat insulation bag, the water vapor was absorbed by the water retention layer and the vinegar content was reduced. As a result, the flavor is not reduced due to transportation.

In addition, the water-retaining layer of this cooked rice heat-insulating bag is
If the surroundings are dry, it has the effect of releasing the built-in moisture, so even if you use it without sealing it without putting it in the transport warmer, the humidity inside the bag will always be kept in an appropriate state, Built-in cooked rice does not dry out.

Further, the food packaging bag formed by using the laminated sheet having the thermoplastic resin thin film formed thereon as the packaging surface layer and having the water-retaining layer disposed on the outside has excellent breathability. Therefore, when a food product that generates water vapor is contained, the water vapor generated from the food product is released to the outside through the ventilation hole, and the released water vapor is absorbed in the water retention layer, so There is no retention or adhesion of water on the surface of the packaging surface layer that comes into contact with it, and dew condensation can be prevented. Therefore, the stickiness of the food contained therein is suppressed, and the food can be transported in a good condition.

Further, in the food packaging bag having the above-mentioned structure, since the water-retaining layer has the function of releasing the water contained therein when the surroundings are dried, for example, the humidity inside the bag is always kept in an appropriate state. The problem that the built-in food dries and the surface hardens does not occur.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a laminated sheet that is an embodiment of the present invention.

FIG. 2 is a schematic view showing a manufacturing process of the laminated sheet of FIG.

FIG. 3 is a usage diagram of a cooked rice heat insulating bag formed of the laminated sheet of FIG.

FIG. 4 is a sectional view of a laminated sheet according to another embodiment of the present invention.

FIG. 5 is a schematic view showing a manufacturing process of the laminated sheet of FIG.

FIG. 6 is a usage diagram of a food packaging bag formed from the laminated sheet of FIG.

[Explanation of symbols]

11,21 Laminated sheet 13 Water retaining layer 15, 27 Packaging surface layer 17 Thermoplastic resin thin film 19 Air reservoir formation layer 22 Vents

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B32B 1/00-35/00 B65D 65/40

Claims (10)

(57) [Claims] 1. A laminated sheet in which a water retention layer having water absorption / moisture releasing properties and a packaging surface layer are directly or indirectly heat-sealed to be laminated and integrated, wherein the packaging surface layer. Is a long-fiber non-woven fabric made of thermoplastic resin
Formed between the water retaining layer and the packaging surface layer, and the thermoplastic resin
The resin thin film is partially heat-sealed to create a large number of scattered air reservoirs.
An air pocket forming layer that forms an air gap is interposed , and vapor diffusion that does not cause dew condensation can be secured in the laminated sheet.
So that a lot of ventilation holes are formed through the sheet
Laminated sheet characterized by being. 2. The packaging surface layer has heat sealability.
The laminated sheet according to claim 1, wherein 3. The method for manufacturing a laminated sheet according to claim 1.
And A water retention layer forming film and a packaging surface layer forming film are provided between the pressure bonding rolls.
At the same time as supplying the rum, thermoplasticity between the two films
A laminating step of extruding resin, A large number of materials are laminated on the material laminated sheet formed in the laminating process.
Consisting of a vent hole forming step of forming a vent hole, One of the pressure-bonding rolls is used as a concavo-convex roll and a water retention layer and packaging
It is possible to form an air pocket forming layer between the surface layer and the surface layer.
A method for manufacturing a laminated sheet. 4. The material laminated sheet is formed by forming the vent hole.
Paper is passed between the needle roll and the brush roll.
The method for manufacturing a laminated sheet according to claim 3, wherein: 5. A water retention layer having water absorption / moisture releasing properties and a packaging surface
Layers and layers are directly or indirectly heat-sealed and laminated
Which is a laminated sheet comprising: The packaging surface layer is formed of a thermoplastic resin thin film, Between the water-retaining layer and the packaging surface layer, the two layers are thermoplastic.
The resin thin film is partially heat-sealed to create a large number of scattered air reservoirs.
An air pocket forming layer for forming The laminated sheet can ensure vapor emission without condensation.
So that a lot of ventilation holes are formed through the sheet
Laminated sheet characterized by being. 6. The packaging surface layer has a heat-sealing property.
The laminated sheet according to claim 5, wherein 7. The method for manufacturing a laminated sheet according to claim 5.
And At the same time as supplying the water retention layer forming film between the pressure rolls
A laminating step of extruding a thermoplastic resin, A large number of materials are laminated on the material laminated sheet formed in the laminating process.
Consisting of a vent hole forming step of forming a vent hole, One of the pressure-bonding rolls is used as a concavo-convex roll and a water retention layer and packaging
It is possible to form an air pocket forming layer between the surface layer and the surface layer.
A method for manufacturing a laminated sheet. 8. The material laminated sheet is formed by forming the vent hole.
Paper is passed between the needle roll and the brush roll.
The method for producing a laminated sheet according to claim 7, wherein: 9. The laminated sheet according to claim 1 or 2 is used.
Formed so that the water retention layer is located outside
A bag for keeping rice warm, which is characterized by being 10. The laminated sheet according to claim 5 or 6.
Use and shape it so that the water retaining layer is located on the outside
A bag for food packaging characterized by being made.