JPH04308722A - Manufacture of vessel for round rice-cake - Google Patents

Abstract

PURPOSE:To open a vessel simply by making molding of a linear thin part easy, by a method wherein extrusion blow molding of plastic is performed by making use of a mold having a cavity in a form of a round rice-cake possessing a fold in a projected line at the time of manufacturing of a vessel for the round rice-cake possessing a linear thin part. CONSTITUTION:A vessel 1 for a round rice cake is constituted of a vessel body part 3 and bottom sheet 4, the vessel body part 3 is blow-molded of plastic into a form of the round rice-cake possessing constricted parts at the vicinities of the center and lower end, and a flange 5 is formed on the lower end part. Then the bottom sheet 4 also is comprised of a sheet made of the plastic, heat- sealed on the lower end of the vessel body part 3 and the vessel body part 3 is sealed up tightly. In the case where the vessel for the round rice-cake like this is manufactured, extrusion blow molding of plastic is performed by making use of a mold having a cavity into form of the round rice-cake possessing a fold in a projected line. With this construction, the vessel is constituted so that a part of the fold is made into a linear thin part 6, a kitchen knife is applied to the thin part 6 and cut into the vessel, through which a rice cake is taken out.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a kagami-mochi container, and more particularly to a method for manufacturing a kagami-mochi container from which mochi can be easily removed.

0002

[Prior Art and Problems to be Solved by the Invention] Since ancient times, kagami-mochi (kagami-mochi) has been made by stacking flat, round mochi in two layers.

[0003] However, this kagami-mochi does not have a sufficiently long shelf life, and has the problem that it becomes moldy within a relatively short period of time, and furthermore, it becomes hard while cracking.

[0004] Therefore, in recent years, so-called packaged kagami-mochi (kagami-mochi), which is a plastic container 1a filled with kagami-mochi (kagami-mochi) 2, has come into wide use, as shown in FIG.

This packaged kagami-mochi uses a container body 3 made by vacuum forming a plastic sheet into the shape of a kagami-mochi with an open bottom.The container body 3 is inverted, filled with mochi 2, and then the bottom is made of plastic. The container was sealed with a sealing sheet (bottom sheet) 4 and then heat-treated. Polypropylene or the like is used for such a container body 3 from the viewpoint of adhesion to the rice cake 2. Moreover, the polypropylene used is of considerable thickness and hardness in order to ensure shape retention and gas barrier properties. In addition, as the bottom sheet 4,
Similar to the container body 3, various plastics are used.

In this packaged kagami mochi, the mochi 2 is removed from the container body 3.
To take out the rice cake, the rice cake 2 is usually cut along with the container body 3 using a knife or the like, and after the cutting, the container body 3 and the rice cake 2 are separated. This is because the body part 3 and the mochi are in close contact with each other.
This is because it is not easy to take out the rice cake just by peeling off the bottom sheet 4. However, when cutting the mochi 2 together with the container body 3 using a knife or the like, since the container body 3 has a certain degree of hardness and wall thickness as described above, a large pressing force is first applied with the knife or the like. Moreover, since the outer surface of the container body 3 is smooth, there is a problem that the knife tends to slip easily and cause injury.

[0007] Thus, vacuum-formed containers are difficult to open. Therefore, by creating linear thin-walled parts or incisions in the original fabric sheet using a cutter or roller, etc., and then performing vacuum forming or pressure forming, a linear thin-walled part is created in the container so that it can be torn by hand. is proposed.

However, when making cuts in plastic sheets using a cutter, roller, etc., it is difficult to control the depth of the cuts, and thin sections obtained by vacuum forming or pressure forming are difficult to control. However, it was found that they do not necessarily have sufficient ease of opening. On the other hand, if the thin-walled part is made quite thin in order to make it easier to open, the container will not only tend to crack from this part during vacuum forming or pressure forming or when filling the container with contents, but also cracks will occur in the event of impact. The problem arises that it is easy to enter.

[0009] Accordingly, an object of the present invention is to provide a method for easily manufacturing a kagami-mochi container that is easy to open and has excellent strength.

0010

[Means for Solving the Problems] In view of the above problems, as a result of intensive research, the present inventors have found that when manufacturing a kagami-mochi container by extrusion blow molding, it is possible to provide a streak on the inner surface of a kagami-mochi-shaped mold cavity. They discovered that the lined portion becomes a linear thin portion, and came up with the present invention.

That is, the method of this embodiment for manufacturing a kagami-mochi container having a linear thin-walled portion is characterized in that plastic is extruded and blow-molded using a mold having a kagami-mochi-shaped cavity having protruding stripes. shall be.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings. 1 and 2 are a side view and a front view, respectively, of the kagami mochi container of the present invention.

The kagami-mochi container 1 consists of a container body 3 and a bottom sheet 4. The container body 3 is made of plastic and blow-molded into a kagami-mochi shape with constrictions near the center and lower end, and a flange 5 is formed at the lower end.

The bottom sheet 4 is also made of a plastic sheet, and is heat-sealed to the lower end of the container body 3 to seal the container body 3. The material of this bottom sheet 4 is as follows:
An easy-peel material is used for the container body 3, so that the sealing sheet (bottom sheet) 4 can be easily peeled off from the container body 3 when taking out the rice cake 2. In such a kagami-mochi container, a thin linear portion 6 is formed on the outer surface of the kagami-mochi-shaped portion of the container body 3.

[0015] The thin wall portion formed in the kagami mochi container is
It does not have to be formed to cross the center of the kagami mochi container as in this embodiment, but it is sufficient that it is at least at a position and long enough to allow the contents to be easily taken out, and similarly, it does not need to be formed across the entire container.

A method for manufacturing such a kagami mochi container will be explained. In the present invention, the plastic forming the kagami-mochi container is not particularly limited, and polyolefins such as polyethylene and polypropylene, polyester, polystyrene, polyamide, polycarbonate, and the like can be used. Particularly preferred is polypropylene. These plastics may be blow molded to form a single layer, or may be blow molded by coextrusion to form a multilayer structure of two or more types.

In the case of a multilayer structure, a three-layer structure such as polypropylene/polyvinyl alcohol/polypropylene or polypropylene/polyamide/polypropylene is preferred, and polypropylene/polyvinyl alcohol/polypropylene is particularly preferred. The above-mentioned polypropylene may contain a certain amount of polypropylene modified with unsaturated carboxylic acid or its anhydride, etc., in order to improve the adhesion between layers.

[0018] In the case of making a kagami mochi container as in this example, higher fatty acids such as stearic acid can be added to the plastic resin for the purpose of improving the peelability from the mochi. In the case of a single layer structure, a higher fatty acid may be added to the plastic, and in the case of a multilayer structure, a higher fatty acid such as stearic acid may be added to the resin of the innermost layer (the surface in contact with the rice cake). When adding higher fatty acids such as stearic acid, the amount added is preferably 0.1 to 5% by weight.

[0019] Such a plastic is extruded and blow molded. The extrusion blow molding method may be any commonly used method, such as screw type, accumulator type,
Examples include screw in-line type. Especially in the case of a multilayer structure, an accumulator type is preferable. For example, in the case of a multilayer structure consisting of polypropylene/polyvinyl alcohol/polypropylene, the resin for each layer is extruded from an accumulator type extruder having a coextrusion die for three types and three layers.
The parison is molded into a cylindrical parison with the desired layered structure, placed in an open mold with a kagami-mochi-shaped cavity, and then closed. ) and then blow it.

However, in the present invention, the mold cavity for blow molding needs to have lines of protrusions. The lines may be provided on the mold depending on the position of the thin wall portion of the kagami mochi container. For example, it is preferable to provide it at the joint of the mold because it is less noticeable. The diameter of this ridge line is 50 μm ~
3 mm, preferably 100 μm to 1 mm, and the height may be about 20 μm to 1 mm. Note that it is preferable that the diameter and height ratio of the striations be small to some extent, and that the tops of the protrusions be somewhat acute, preferably less than 60°. This is to make it easier to reduce the thickness of the part that contacts the striations.

[0021] As for the mold, it is preferable to use one that includes the shape of a kagami-mochi container and has an appropriate shape starting from the lower end. After producing an intermediate molded body including the shape of a kagami-mochi container using a mold having such a shape, the flange portion can be easily formed by cutting the kagami-mochi container from it.

[0022] The thickness of such a kagami-mochi container varies depending on the size, shape, weight, etc. of the kagami-mochi, but it can be adjusted as appropriate depending on the thickness of the cylindrical parison during extrusion and the size of the mold. Can be done. For example, since the weight of mochi filled in the mochi container body 3 is usually about 160 g to 8 kg,
It is preferably about 0 μm to 1.5 mm. If the thickness of the kagami-mochi container is less than 550 μm, it will be difficult to maintain the kagami-mochi shape during filling with mochi, and it will be difficult to have gas barrier properties. becomes difficult.

The extrusion temperature may be appropriately set depending on the type of plastic used; for example, in the case of polypropylene, it is about 180 to 300°C.

[0024] Such a kagami mochi container of the present invention usually has a sealing sheet that seals the bottom (opening). As for the sealing sheet, various plastics can be used in the same way as for the above-mentioned container body, but it is particularly preferable to use single-layer materials such as polypropylene, polyethylene, etc., and laminates of these materials with polyester, aluminum foil, etc. . Its thickness is preferably 70 to 100 μm. The size of the sealing sheet should be such that it can completely cover at least the opening at the bottom of the container. Further, its shape may be similar to that of the flange portion of the kagami mochi container.

[0025] Packaging can be accomplished by heat-sealing such a sealing sheet to the bottom of the container after it is filled with rice cake.

[0026] For the kagami mochi container obtained by the method of this embodiment, for example, first the sealing sheet is peeled off from the container body, then a knife is applied to the thin wall part 6, the container is cut, and the mochi 2 is taken out. . Also, hold the flange part by hand,
The rice cake 2 can also be easily taken out by tearing the container body along the thin wall portion 6 through a notch (not shown).

Although the present invention has been described above with reference to the accompanying drawings, the present invention is not limited thereto, and can be applied to various containers by appropriately changing the position, length, shape, etc. of the thin wall portion 6. It can be a body part.

The present invention will be explained in more detail by the following specific examples. Example 1 Polypropylene and polyvinyl alcohol were molded using a multilayer blow molding machine to produce a kagami mochi container body having a three-layer structure of polypropylene/polyvinyl alcohol/polypropylene. The mold used was shaped like a kagami-mochi container and had protrusions from the top to the bottom of the kagami-mochi.

The obtained kagami-mochi container body was filled with 550 g of mochi, and after cooling, the bottom of the kagami-mochi container body was heat-sealed with a laminated sheet (80 μm) of polyester and nylon. This wrapped kagami-mochi could be easily torn by hand along the linear thin wall portion.

[0030]

Effects of the Invention As detailed above, according to the method for manufacturing a kagami-mochi container of the present invention, when manufacturing a kagami-mochi container by extrusion blow molding, lines are provided in the mold in the shape of kagami-mochi, so that lines can be removed. This makes it possible to easily form thin-walled parts.

[Brief explanation of drawings]

FIG. 1 is a side view of a kagami mochi container according to an embodiment of the present invention.

FIG. 2 is a front view of a kagami mochi container according to an embodiment of the present invention.

FIG. 3 is a longitudinal cross-sectional view showing a state in which the kagami mochi container is filled with mochi.

[Explanation of symbols]

1...Kagami-mochi container 2...Mochi 3... Container body 4...Bottom sheet 5...Flange part 6...Thin wall part

Claims (1)

[Claims] [Claim 1] A method for manufacturing a kagami mochi container having a linear thin wall portion, characterized in that plastic is extruded and blow molded using a mold having a kagami mochi-shaped cavity having protruding stripes. Method for manufacturing kagami-mochi containers.