JP6529334B2 - Pulp mold container - Google Patents

Description

  The present invention relates to a pulp mold container, a method of manufacturing the pulp mold container, and a method of manufacturing a food package using the pulp mold container.

Conventionally, a pulp mold container is generally used as a container which is excellent in easy discardability.
In addition, as such a pulp mold container, one in which a synthetic resin film is laminated on the inner surface or the like of a main body made of a pulp mold as in Patent Document 1 is known as one that improves water resistance and the like.

JP 2003-128120 A

  By the way, as one of the uses of such a pulp mold container, what is used as a cooking appliance which performs food preparation by filling a container with food and then putting the container in a heating furnace or the like can be mentioned.

However, according to this type of heating method in which heat is directly applied to the pulp mold container, the synthetic resin film laminated on the main body partially peels off from the main body and expands, generally referred to as a blister. A phenomenon may occur.
Although the performance as a container itself is not affected as long as the blistering is limited to a very small amount, it may be disposed of as a defective product at the time of shipment because the aesthetic appearance is lost.
Therefore, the occurrence of blistering substantially affects the yield of the pulp mold container or the food package formed by filling the container with the food.

  Therefore, the problem to be solved by the present invention is to suppress the generation of a blister at the time of heating, in relation to a pulp mold container in which a synthetic resin film is laminated on at least one side of a main body made of pulp mold.

  The present inventors for the first time identify the fact that the amount of water contained in the main body of a pulp mold container is highly correlated with the occurrence of fire expansion, and restrict the amount of water to a certain amount or less. Succeeded in dramatically suppressing

That is, the pulp mold container according to the present invention is provided with a main body made of pulp mold, and a resin film laminated on at least one side of the main body, and the water occupied in the main body is 4.0% by weight or less. It is
As such a pulp mold container of the present invention, it is preferable that the main body contains cellulose fiber as a main component, and the resin film is a thermoplastic resin film and is laminated to the main body by welding.

Further, as a method for producing a pulp mold container according to the present invention, a step of preparing a main body made of pulp mold, a step of laminating a resin film on at least one side of the main body, and drying the main body on which the resin film is laminated And adjusting the water content in the main body to 4.0% by weight or less.
As a manufacturing method of such a pulp mold container of the present invention, the process of adjusting the moisture of the main part on which the resin film was laminated is heating by heating temperature of 100 ° C-260 ° C and heating time of 1 minute-10 minutes. Preferably, it is done dry.

Furthermore, as a method for producing a food package according to the present invention, a step of preparing a main body made of pulp mold, a step of laminating a resin film on at least one side of the main body, and a food is laminated on the main body A step of filling, a preheating step of heating the main body in which the resin film is laminated and the food is filled to adjust the water content in the main body to be 4.0% by weight or less, and the resin film is laminated And the main heating step of heating the main body, which is filled with the food and whose water content is adjusted, to heat and cook the food.
In the method of manufacturing a food package according to the present invention, the main body on which the resin film is laminated is conveyed by a conveyor while passing through a heating furnace, thereby preheating the upstream half of the heating furnace in the conveying direction. It is preferable that the process be performed and that the main heating process be performed on the downstream half of the heating furnace in the conveyor conveyance direction.

  As described above, in the case of a pulp mold container formed by laminating a synthetic resin film on at least one side of the main body made of pulp mold, by configuring the water content in the main body to be 4.0% by weight or less, It became possible to suppress the occurrence of

Cross-sectional view of the pulp mold container of the embodiment A figure showing a part of manufacturing process of a pulp mold container of an embodiment The figure which shows a part of manufacturing process of the food packaging body of embodiment

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the pulp mold container 10 of the embodiment includes a main body 11 made of pulp mold, and a synthetic resin film 12 laminated on the inner surface of the outer surface and the inner surface of the main body 11. The amount of water occupied is adjusted to 4.0% by weight or less.
The food 13 is filled in the pulp mold container 10 of this embodiment, and the whole container is heated and cooked, and then sealed by the lid 14 to constitute the food package of the embodiment.
The shape of the pulp mold container 10 according to the embodiment is not particularly limited, but as a general one, the bottom wall, a peripheral wall extending and rising from the peripheral edge of the bottom wall, and a flange protruding substantially horizontally from the upper edge of the peripheral wall What has it can be illustrated, and as a plan view shape of the bottom wall, a circle, an ellipse, and a square can be exemplified.

The main body 11 made of pulp mold is made of pulp material such as straw or sugar cane as a raw material and its cellulose fiber as a main component, and the water content is conventionally adjusted as described above, except that The same as the main body in the pulp mold container of
Although the manufacturing method of the main body in the front step which adjusts moisture content is not specifically limited, For example, it is by the following well-known manufacturing methods.
That is, a pulp suspension is prepared, this is put out in a mesh shape, and while heating the formed material, it is pressed by a male and female press die, and the end portion of the pressed material is appropriately cut etc. Molding can be exemplified. It goes without saying that processes such as foreign substance contamination inspection using a metal detector or the like and sterilization such as irradiation with ultraviolet light may be appropriately attached.
The type of pulp, the type of binder, the number of mesh meshes, the heating temperature, the pressing pressure, the pressing time, the clearance between male and female molds, etc. are not particularly limited, however, JP 2011-157662 by the same applicant. The contents described in the publication can be exemplified.
The thickness of the main body 11 is also not particularly limited, but if the thickness is too small, the strength will be insufficient, and if the thickness is too large, the material cost will increase, etc. Is preferred.

The synthetic resin film 12 laminated on the inner surface of the main body 11 imparts water resistance to the pulp mold container 10 of the embodiment, and when the pulp mold container 10 of the embodiment is filled with a water-rich food, etc. , To prevent the body 11 from being contaminated with food moisture.
The type of the synthetic resin is not particularly limited, but examples thereof include polyolefin resins such as polypropylene (PP) and polyethylene (PE), and polyester resins such as polyethylene terephthalate (PET) and polylactic acid (PLA). It is preferable that it is a thermoplastic resin as what can be sealed.
The synthetic resin film 12 is not limited to a single layer, and, for example, as an adhesive layer on the surface on the side in contact with the main body 11 for the purpose of enhancing adhesion with the main body 11 in addition to the films An ethylene-vinyl acetate copolymer (EVA) or an ethylene-methacrylic acid copolymer (EMMA) may be laminated.
Specifically, the gravure printing is performed on a 25 μm-thick PET film, the anchor coating is performed on the printing ink with a gravure plate, the adhesive layer is laminated on the anchor coat to a thickness of 25 μm, and the adhesive layer is It can be exemplified that it is laminated on the inner surface of the main body 11 on the side of the main body 11.
Moreover, printing, aluminum vapor deposition, etc. may be suitably performed on the synthetic resin film 12.
The thickness of the synthetic resin film 12 is also not particularly limited, but if the thickness is too small, the water resistance performance and the like will be insufficient, and if the thickness is too large, it may deviate from the definition of a paper container referred to in the Containers and Packaging Recycling Law, Since it can not be done, 5 to 200 μm is preferable.

The method of laminating the synthetic resin film 12 on the main body 11 is not particularly limited either, but may be, for example, the following known method.
First, as shown in FIG. 2A, prepare a device in which a mold M is disposed at the lower side and a heater H is disposed at the upper side, and the main body 11 is set to the mold M. Supply a thermoplastic synthetic resin film 12 between them.
Here, when a negative pressure is applied to a suction hole (not shown) provided in the mold M using a suction mechanism or the like, the main body 11 set in the mold M is made of pulp mold and has air permeability. As shown by the arrow in FIG. 2B, the synthetic resin film 12 heated and softened by the heater H is attracted toward the main body 11 and welded to the inner surface of the main body 11.
Finally, as shown in FIG. 2C, the synthetic resin film 12 remaining on the outer edge is appropriately cut by the Thomson blade T. Of course, other known methods can be substituted for the method of cutting.
In this case, the heating temperature and heating time of the synthetic resin film 12 by the heater H, the size and number of the suction holes of the mold M, the size of the suction force accompanying it, the suction time, etc. It is.
In order to compensate for the suction force of the suction holes, appropriate measures may be made such as providing a large number of fine holes in the main body 11 with a cone or the like to enhance the air permeability. The contents described in Japanese Patent Application Publication Nos. 2014-144612, 2014-144613, and 2014-145142 by the same applicant as the present applicant can be exemplified.

After the synthetic resin film 12 is laminated on the inner surface of the main body 11 molded as described above as described above, the pulp mold container 10 of the embodiment is subjected to another drying treatment to obtain the water content in the main body 11 Is specially adjusted so as to be 4.0% by weight or less.
Specifically, the process of laminating the synthetic resin film 12 on the inner surface of the molded main body 11 was performed at a specific place (such as a factory), and this was moved to another place (such as another factory) by transportation or the like It can be assumed that the drying process is performed on the top and the water content in the main body 11 is finally adjusted.
By adjusting the water content in the main body to 4.0% by weight or less as described above, the occurrence of fire expansion at the time of heating the container 10 is sufficiently suppressed.
The proof of the effect will be given to the examples described later, but considering the mechanism from the mechanism, the water contained in the main body 11 is vaporized and expanded at the time of heating, and the vaporized and expanded water vapor is released from the main body 11, It is inferred that entering between the main body 11 and the synthetic resin film 12 is the main cause of the generation of the fire blister.
Therefore, by suppressing the amount of water contained in the main body 11, it is considered that the fire expansion can be suppressed by suppressing the amount of water vapor generated from the main body 11 at the time of heating and causing the fire expansion.
From this, the lower limit value of the water content is not particularly determined, and theoretically, as it approaches 0% by weight, the fire expansion can be further prevented.
On the other hand, with regard to the upper limit value of the water content, 4.0% by weight, an experimental significant difference was found in the presence or absence of the occurrence of the blistering before and after 4.0% by weight as in the example described later. It originates in Incidentally, in the conventional pulp mold container, the water content of the main body is usually 5.5% by weight or more.

The drying method is not particularly limited, and examples thereof include drying with heating in a heating furnace and the like, drying with a dryer and the like, and drying by forced evaporation of water with a vacuum device and the like. It is preferable from the viewpoint of mass production to carry out by passing the heating furnace while conveying the main body on which the resin film is laminated by a conveyer.
Further, the timing and place of the water adjustment of the main body 11 are not particularly limited.
For example, after the container maker itself adjusts the moisture of the main body 11 in the pulp mold container 10 by heating or the like, the container is sealed with a special package so that the moisture of the main body 11 does not change. It can be assumed that 10 will be shipped to food manufacturers.

On the other hand, a container manufacturer ships a pulp mold container for which the moisture adjustment of the main body 11 has not been made, and the food manufacturer to which this is delivered, moisture adjustment of the main body 11 just before filling and cooking food with the pulp mold container. It can also be assumed that
Thus, when the moisture adjustment of the main body 11 is performed in the food maker, as a heating step, a preheating step for adjusting the moisture of the main body 11 and a book for cooking food filled in the pulp mold container 10 Two types of heating can be performed: a heating step.
In that case, although the preheating step and the main heating step may be performed separately by different heating furnaces or the like, as shown in FIG. 3, the moisture adjustment of the main body 11 of the pulp mold container 10 and the pulp mold container 10 are filled. It is preferable to perform heating and cooking of the food 13 continuously by a single heating furnace F because it is efficient.
That is, while the main body 11 on which the synthetic resin film 12 is stacked is filled in advance with the food 13 is transported by the conveyor C, it passes through the heating furnace F, and the main body 11 is upstream of the heating furnace F in the conveyor transport direction. A preheating step of adjusting the water content is performed, and the food 13 is cooked on the downstream side in the conveyor conveyance direction. In addition, FIG. 3 is a schematic diagram, and the length dimension of the heating furnace F is actually large enough compared with the dimension of the pulp mold container 10. As shown in FIG.
Thereafter, the pulp mold container 10 is sealed by, for example, covering the lid 14, and is shipped as a food package.

Although the heating temperature, heating time, and the like in the case of heat treatment for adjusting the amount of water contained in the main body 11, that is, the method of manufacturing the pulp mold container 10 of the embodiment are not particularly limited, for example It can be exemplified that the entire pulp mold container 10 of the embodiment is placed in a heating furnace and heated at 100 ° C. to 260 ° C. for 1 minute to 10 minutes.
If the heating temperature is below 100 ° C., evaporation of water inside the main body 11 will be insufficient, and if it exceeds 260 ° C., the melting point of the synthetic resin film 12 may be exceeded and the synthetic resin film 12 may be adversely affected. is there.
Also, if the heating time is less than one minute, the evaporation of the water inside the main body 11 will be insufficient, and even if it exceeds 10 minutes, the water will be almost evaporated, so the heating is ineffective and inefficient. It is.
From the above reasons, it is more preferable that the heating temperature be 100 ° C. to 140 ° C., and the heating time be 4 minutes to 8 minutes.

  The features of the present invention will be further clarified by the following examples and comparative examples.

As shown in Table 1, a pulp mold container is formed by laminating a 50 μm thick PET film by vacuum drawing as shown in FIG. 2 on the inner surface of a 0.6 mm thick pulp mold made of cellulose fibers. Examples 1-4 and Comparative Examples 1 and 2 were prepared in which the heating temperature and heating time of the pulp mold container and the water content of the main body were different. In addition, in Table 1, about the comparative example 2, it means that the drying process by heating is not performed.
In addition, the measurement of a moisture content followed the formula (P-Pd) / (P-F).
In the formula, P represents the weight of the pulp mold container after heating.
In the formula, F represents the weight of the PET film, which is calculated by removing the weight of the main body from the weight of the pulp mold container before heating.
Furthermore, in the formula, while the pulp mold container is heated at a heating temperature of 100 ° C., the weight is measured at regular time intervals, and the weight change with the previously measured weight is almost zero. It is weight and represents the weight when it is assumed that the moisture from the pulp mold container is almost completely evaporated.

Ten pulp mold containers of each of Examples 1 to 4 and Comparative Examples 1 and 2 are prepared, and each 200 g of white sauce manufactured by Heinz Japan Co., Ltd. is filled to prepare a food package, which is used as an oven ( It cooked under the conditions of the heating temperature of 210 degreeC, and the heating time for 6 minutes and 30 seconds by Fujimac make part number FSCC6).
With respect to 10 pulp mold containers of each of Examples 1 to 4 and Comparative Examples 1 and 2 which had been cooked, the presence or absence of the occurrence of fire expansion was visually confirmed.
The results are shown in Table 2, and it was confirmed that the occurrence of fire expansion is significantly suppressed when the moisture content of the main body is 4.0% by weight or less.

  It should be considered that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is indicated by the claims, and is intended to include all the modifications and variations within the meaning and scope equivalent to the claims.

For example, in the embodiment, in the pulp mold container 10, the synthetic resin film 12 is laminated on the inner surface of the main body 11, but may be laminated on the outer surface of the main body 11, or laminated on both the inner surface and the outer surface May be
In the embodiment, the synthetic resin film is laminated on substantially the entire inner surface of the main body, but the lamination may be partially missing.
When laminating the synthetic resin film 12 on the main body 11 as shown in FIG. 2, in principle, only the single side of the main body 11 can be laminated when using a vacuum drawing technique, but for example, the main body by vacuum drawing By laminating the synthetic resin film 12 on the outer surface of 11 and providing air permeability by forming a large number of fine holes in the film by means of a pyramid or the like, it is possible to laminate the film also on the inner surface by vacuum suction. .

10 Pulp mold container 11 of the embodiment Body 12 Synthetic resin film 13 Food 14 Lid M Mold H Heater T Thomson blade F Heating furnace C Conveyor

Claims (6)

A body made of pulp mold,
And a resin film laminated only on the inner surface of the main body,
A pulp mold container having a water content of 4.0% by weight or less in the main body;
The food filled in the pulp mold container;
A food package capable of cooking the food together with the pulp mold container . The body is mainly composed of cellulose fiber,
The food package according to claim 1, wherein the resin film is a thermoplastic resin film and is laminated to the main body by welding. Preparing a body comprising a pulp mold;
Laminating a resin film on at least one side of the main body;
And drying the main body on which the resin film is laminated to adjust the water content in the main body to be 4.0% by weight or less.   The pulp mold container according to claim 3, wherein the step of adjusting the moisture of the main body on which the resin film is laminated is performed by heating and drying by a heating temperature of 100 ° C to 260 ° C and a heating time of 1 minute to 10 minutes. Production method. Preparing a body comprising a pulp mold;
Laminating a resin film on at least one side of the main body;
A step of filling the main body on which the resin film is laminated with food;
A preheating step of heating the main body in which the resin film is stacked and filled with food so that the water content in the main body is 4.0% by weight or less;
And a main heating step of heating the main body, wherein the resin film is laminated, the food is filled, and the water content is adjusted, and the food is heated and cooked.   By passing the heating furnace while conveying the main body on which the resin film is laminated by the conveyor, the preheating step is performed on the upstream side of the heating furnace in the conveyor conveyance direction, and the heating furnace on the downstream side of the conveyor conveyance direction The method for producing a food package according to claim 5, wherein the heating step is performed.

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