JP2016216055A - Pulp mold container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulp mold container obtained by laminating a synthetic resin film on at least one surface of a body comprising a pulp mold, and suppressed in generation of expansion due to heat when filling and cooking a food.SOLUTION: A pulp mold container is so formed as to have a moisture content of 4.0 wt.% or less in the body thereof. Since it is considered that a main factor of generation of expansion due to heat is that moisture contained in the body 11 is evaporation expanded when heating, and the evaporation expanded steam is discharged from the body 11 and goes into between the body 11 and the synthetic resin film 12, a moisture content contained in the body 11 is suppressed to a specified quantity or less so as to suppress an amount of steam generated from the body 11 when heating, and becoming a factor of expansion due to heat and suppress expansion due to heat.SELECTED DRAWING: Figure 1

Description

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

Conventionally, a pulp mold container is widely used as a container excellent in easy disposal.
Moreover, as for what improves water resistance etc. about such a pulp mold container, what laminated | stacked the synthetic resin film on the inner surface etc. of the main body which consists of a pulp mold like patent document 1 is also known.

JP 2003-128120 A

  By the way, as one of the uses of such a pulp mold container, what is used also as a cooking utensil which cooks food by filling a container with food and putting it into a heating furnace together can be cited.

However, according to this kind of heating method in which heat is directly applied to the pulp mold container, the synthetic resin film laminated on the main body is partially peeled off from the main body and expands. A phenomenon may occur.
As long as the blisters are limited, there is no effect on the performance of the container itself. However, since the aesthetics are lost, it may be disposed of as a defective product before shipping.
Therefore, the occurrence of blistering has a detrimental effect on the yield of a food packaging body formed by filling a pulp mold container or food in the container.

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

  The present inventors have found for the first time the fact that the amount of moisture contained in the main body of the pulp mold container is greatly correlated with the occurrence of blistering, and the occurrence of blistering by limiting the amount of moisture to a certain amount or less. Was successfully suppressed.

That is, the pulp mold container according to the present invention comprises a main body made of a pulp mold and a resin film laminated on at least one side of the main body, and the moisture content in the main body is 4.0% by weight or less. It was.
As such a pulp mold container of this invention, the said main body has a cellulose fiber as a main component, the said resin film is a thermoplastic resin film, and what was laminated | stacked on the said main body by welding is preferable.

Further, as a method for producing a pulp mold container according to the present invention, a step of preparing a main body made of a pulp mold, a step of laminating a resin film on at least one side of the main body, and a main body on which the resin film is laminated are dried. And a step of adjusting the moisture content in the main body to be 4.0% by weight or less.
As a method for producing the pulp mold container of the present invention, the step of adjusting the water content of the main body on which the resin film is laminated is performed by heating at a heating temperature of 100 ° C. to 260 ° C. and a heating time of 1 minute to 10 minutes. It is preferable to carry out by drying.

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

  As described above, for a pulp mold container in which a synthetic resin film is laminated on at least one side of a main body made of a pulp mold, the water content in the main body is configured to be 4.0% by weight or less, so that the blister during heating is increased. It became possible to suppress the occurrence of.

Sectional drawing of pulp mold container of embodiment The figure which shows a part of manufacturing process of the pulp mold container of 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 a 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 water content is adjusted to 4.0% by weight or less.
The pulp mold container 10 of this embodiment is filled with the food 13 and cooked together with the container, and then sealed with the lid 14 to constitute the food package of the embodiment.
The shape of the pulp mold container 10 of the embodiment is not particularly limited, but as a general thing, a bottom wall, a peripheral wall that spreads and rises from the periphery of the bottom wall, and a flange that protrudes substantially horizontally from the upper edge of the peripheral wall, The bottom wall can be exemplified by a circular shape, an elliptical shape, and a rectangular shape.

The main body 11 made of a pulp mold is made of a pulp material such as straw or sugar cane as a raw material, and has a cellulose fiber as a main component, and the conventional method, except that the water content is particularly adjusted as described above. This is the same as the main body in the pulp mold container.
Although the manufacturing method of the main body in the previous stage of adjusting the moisture content is not particularly limited, for example, it is based on the following known manufacturing method.
That is, by preparing a pulp suspension, making it into a net, and pressing the finished product with a male and female press mold while heating, appropriately cutting the end of the pressed product, etc. An example is molding. It goes without saying that steps such as inspection for contamination by a metal detector or the like and sterilization by irradiation with ultraviolet light or the like may be appropriately attached.
Pulp type, binder type, mesh number of meshes, heating temperature, pressing pressure, pressing time, clearance between male and female molds are not particularly limited, but Japanese Patent Application Laid-Open No. 2011-157661 by the same applicant as the present applicant. The contents described in the Gazette can be exemplified.
Although the thickness of the main body 11 is not particularly limited, the strength is insufficient when the thickness is too small, and is 0.2 to 5.0 mm for general reasons such as an increase in material cost when the thickness is too large. It is preferable.

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 food with a lot of moisture. The main body 11 is prevented from being contaminated with water of food.
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. For example, in addition to the film of the material as exemplified above, the synthetic resin film 12 is used as an adhesive layer on the surface in contact with the main body 11 for the purpose of improving the adhesion with the main body 11. An ethylene-vinyl acetate copolymer (EVA), an ethylene-methacrylic acid copolymer (EMMA), or the like may be laminated.
Specifically, gravure printing is performed on a PET film having a thickness of 25 μm, an anchor coating is performed on the printing ink with a gravure plate, and an adhesive layer is laminated on the anchor coat with a thickness of 25 μm. It is possible to exemplify laminating on the inner surface of the main body 11 on the main body 11 side.
In addition, the synthetic resin film 12 may be appropriately printed, aluminum-deposited, or the like.
The thickness of the synthetic resin film 12 is not particularly limited. However, if the thickness is too small, the water resistance performance is insufficient, and if the thickness is too large, it is out of the definition of a paper container in the Containers and Packaging Recycling Law, and may be discarded as combustion waste. Since it becomes impossible, 5-200 micrometers is preferable.

The method for laminating the synthetic resin film 12 on the main body 11 is not particularly limited, but may be, for example, the following known method.
First, as shown in FIG. 2 (a), an apparatus is prepared in which a mold M is disposed below and a heater H is disposed above, and the main body 11 is set in the mold M. The thermoplastic synthetic resin film 12 is supplied during this period.
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 a pulp mold and has air permeability. 2B, the synthetic resin film 12 heated and softened by the heater H is sucked 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, the cutting method can be replaced by other known methods.
In this case, the heating temperature and heating time of the synthetic resin film 12 by the heater H, the size and number of suction holes of the mold M, the size of the suction force associated therewith, the suction time, etc. are not particularly limited and can be adjusted as appropriate. It is.
Further, in order to supplement the suction force of the suction holes, appropriate measures can be taken, such as providing a large number of fine holes with cones or the like in the main body 11 to improve air permeability. The contents described in JP 2014-144612 A, JP 2014-144613 A, and JP 2014-145142 A by the same applicant as the present applicant can be exemplified.

In the pulp mold container 10 of the embodiment, after the synthetic resin film 12 is laminated on the inner surface of the main body 11 formed as described above, the moisture content in the main body 11 is again performed by drying treatment. Is specially adjusted so as to be 4.0% by weight or less.
Specifically, the process up to the step 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 moved to another place (such as another factory) by transportation or the like. It can be assumed that the drying process is performed and the water content in the main body 11 is finally adjusted.
Thus, by adjusting the water content in the main body to 4.0 wt% or less, the occurrence of blistering during heating of the container 10 is sufficiently suppressed.
The proof of the effect will be left to the examples described later, but considering this in terms of mechanism, the moisture contained in the main body 11 is vaporized and expanded upon heating, and the vaporized and expanded water vapor is released from the main body 11, It is estimated that entering between the main body 11 and the synthetic resin film 12 is a main cause of the occurrence of blisters.
Therefore, it is considered that by suppressing the amount of water contained in the main body 11, it was possible to suppress the blister by suppressing the amount of water vapor generated from the main body 11 during heating and causing the blister.
From this, the lower limit of the amount of water is not particularly defined, and theoretically, the closer to 0% by weight, the more the blister can be prevented.
On the other hand, as to the upper limit of the moisture content of 4.0% by weight, a significant difference was experimentally observed with respect to the occurrence of blistering around 4.0% by weight, as in the examples described later. Derived from. Incidentally, in the conventional pulp mold container, the moisture content of the main body is usually 5.5% by weight or more.

The drying method is not particularly limited, and examples include drying with heating in a heating furnace, drying with a dryer, drying by forcibly evaporating moisture with a vacuum device, etc. It is preferable from the viewpoint of mass production that the main body on which the resin film is laminated is passed through a heating furnace while being conveyed by a conveyor.
Also, the timing and location of moisture adjustment of the main body 11 are not particularly limited.
For example, after the container manufacturer itself performs moisture adjustment of the main body 11 in the pulp mold container 10 by heating or the like, the pulp mold container 10 is sealed with special packaging so that the water content of the main body 11 does not change. It can be assumed that 10 is shipped to a food manufacturer.

On the other hand, the container manufacturer ships a pulp mold container in which the moisture content of the main body 11 is not adjusted. In the food manufacturer to which the pulp mold container is delivered, the moisture adjustment of the main body 11 is performed immediately before filling the pulp mold container with food and cooking. It can also be assumed that
Thus, when adjusting the moisture of the main body 11 in the food manufacturer, as a heating process, a preheating process for adjusting the moisture of the main body 11 and a book for cooking the food filled in the pulp mold container 10 by heating. Two types of heating, the heating step, can be performed.
In that case, the preheating step and the main heating step may be performed separately by different heating furnaces or the like. However, 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 were filled. It is preferable to continuously cook the food 13 with the single heating furnace F because it is efficient.
That is, the main body 11 on which the synthetic resin film 12 is laminated is preliminarily filled with the food 13 and is conveyed by the conveyor C while being passed through the heating furnace F. A preheating step for adjusting the amount of moisture is performed, and the food 13 is cooked on the downstream side in the conveyor conveyance direction. Note that FIG. 3 is a schematic diagram, and in actuality, the length dimension of the heating furnace F is sufficiently larger than the dimension of the pulp mold container 10.
Thereafter, the pulp mold container 10 is sealed with a cover 14 or the like and shipped as a food package.

In addition, although it does not specifically limit about the heating temperature in the case of heat processing for adjusting the moisture content contained in the main body 11, ie, as a manufacturing method of the pulp mold container 10 of the embodiment, for example, It can be exemplified that the entire pulp mold container 10 of the embodiment is put in a heating furnace and heated at 100 ° C. to 260 ° C. for 1 minute to 10 minutes.
If the heating temperature is lower than 100 ° C., the evaporation of moisture in the inside of the main body 11 becomes insufficient, and if it exceeds 260 ° C., the melting point of the synthetic resin film 12 may be exceeded, which may adversely affect the synthetic resin film 12. is there.
Also, if the heating time is less than 1 minute, the evaporation of moisture inside the main body 11 is insufficient, and even if it exceeds 10 minutes, the moisture will already be evaporated, so there is no practical benefit of heating and it is inefficient. It is.
For the above reasons, it is more preferable that the heating temperature is 100 ° C. to 140 ° C. and the heating time is 4 minutes to 8 minutes.

  Hereinafter, the features of the present invention will be further clarified by giving examples and comparative examples.

Table 1 shows a pulp mold container in which a PET film having a thickness of 50 μm is laminated by vacuuming as shown in FIG. 2 on the inner surface of a 0.6 mm thick pulp mold composed of cellulose fibers. Examples 1-4 and Comparative Examples 1 and 2 in which the heating temperature and heating time of the pulp mold container and the moisture content of the main body were different were prepared. In Table 1, Comparative Example 2 means that the drying process by heating is not performed.
The moisture content was measured according to the formula (P-Pd) / (PF).
In the formula, P indicates the weight of the heated pulp mold container.
In the formula, F represents the weight of the PET film, and is calculated by excluding the weight of the main body from the weight of the pulp mold container before heating.
Furthermore, Pd in the formula is measured when the pulp mold container is heated at a heating temperature of 100 ° C. with a certain time interval, and the weight change from the last measured weight becomes almost zero. It is a weight and shows the weight when it is assumed that the water has almost completely evaporated from the pulp mold container.

Ten pulp mold containers of each of Examples 1 to 4 and Comparative Examples 1 and 2 were prepared, and 200 g of white sauce manufactured by Heinz Japan Co., Ltd. was filled to prepare a food package. The product was cooked under the conditions of a heating temperature of 210 ° C. and a heating time of 6 minutes 30 seconds using a product number FSCC 6) manufactured by Fuji Mac.
The presence or absence of the occurrence of blistering was visually confirmed for each of the ten pulp mold containers of Examples 1 to 4 and Comparative Examples 1 and 2 that had finished cooking.
The results are shown in Table 2, and it was confirmed that the occurrence of blistering was significantly suppressed when the moisture content of the main body was 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 defined by the terms of the claims, and is intended to include any modifications and variations within the scope and meaning equivalent to the terms of the claims.

For example, in the embodiment, the synthetic resin film 12 is laminated on the inner surface of the main body 11 in the pulp mold container 10, but may be laminated on the outer surface of the main body 11, or may be laminated on both the inner surface and the outer surface. May be.
In the embodiment, the synthetic resin film is laminated on almost the entire inner surface of the main body, but the lamination may be partially lost.
As shown in FIG. 2, in the case of using the vacuuming technique when laminating the synthetic resin film 12 on the main body 11, in principle, it can be laminated only on one side of the main body 11. The synthetic resin film 12 is laminated on the outer surface of 11, and the film can be laminated by vacuuming on the inner surface by providing air permeability by forming a large number of fine holes with cones or the like on the film. .

10 pulp mold container 11 main 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,
A resin film laminated on at least one side of the main body,
The pulp mold container whose water | moisture content in the said main body is 4.0 weight% or less. The main body is mainly composed of cellulose fibers,
The pulp mold container according to claim 1, wherein the resin film is a thermoplastic resin film and is laminated on the main body by welding. A step of preparing a main body comprising a pulp mold;
Laminating a resin film on at least one side of the main body;
Drying the main body on which the resin film is laminated, and adjusting the water content in the main body to be 4.0% by weight or less.   The process of adjusting the water | moisture content of the main body on which the said resin film was laminated | stacked is performed by the heating drying by the heating temperature of 100 to 260 degreeC, and the heating time of 1 minute-10 minutes, The pulp mold container of Claim 3 Production method. A step of preparing a main body comprising a pulp mold;
Laminating a resin film on at least one side of the main body;
Filling the body with the resin film laminated with food;
A preheating step of heating the main body on which the resin film is laminated and filled with food, and adjusting the water content in the main body to be 4.0% by weight or less;
A main heating step in which the resin film is laminated, the food is filled and the moisture content is adjusted, and the main body is heated to cook the food.   By passing the heating furnace through the conveyor while transporting the main body on which the resin film is laminated, a preheating step is performed on the upstream side in the conveyor conveyance direction of the heating furnace, and on the downstream side in the conveyor conveyance direction of the heating furnace. The manufacturing method of the food packaging body of Claim 5 in which this heating process is performed.

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