JP4595203B2 - Manufacturing method of barrier plastic cup container - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a barrier plastic cup container used for contents requiring a barrier property against oxygen, such as pasta sauce and soup, and a method for producing the same.
[0002]
[Prior art]
Conventionally, plastic cup containers used for contents requiring barrier properties include cup containers formed by sheet-molding barrier laminated plastic sheets and cup containers injection molded by barrier resin, but the former cups. Since the container is formed from a sheet on which characters and designs that describe the product are printed, the characters and designs are deformed, resulting in poor design, and the container may have a large uneven thickness. The cup container is expensive in molding resin, and since the melt viscosity is high, a thin container cannot be formed, and the container becomes thick, resulting in high production costs. For this reason, many inventions and devices relating to the imparting of barrier properties to plastic cup containers have been made. For example, the barrier in-mold labels (111, 122) shown in FIG. 2 disclosed in JP-A-9-174595 are used as side walls. There has been known a barrier plastic container (100) thermally fused to a (110) surface and a bottom surface (120).
[0003]
[Problems to be solved by the invention]
However, the container in which the above-mentioned barrier in-mold label is heat-sealed to the bottom surface and the side wall surface has a sufficient effect on the barrier property of the container due to the shift of the barrier in-mold label heat-sealed to the bottom surface or generation of wrinkles. May not be able to demonstrate.
[0004]
The present invention has solved the conventional problems described above, good barrier properties, good design property and appearance, no uneven thickness, relatively manufacturing cost is inexpensive barrier plastic cup container manufacturing A method is provided.
[0005]
[Means for Solving the Problems]
[0006]
That is , in the first invention of the present invention, a barrier in-mold label is inserted in advance into the cavity surface forming the peripheral wall of the female mold of the injection mold, and into the mold at the first injection stage. The base molding resin is injected to form the peripheral wall, and at the same time, the barrier in-mold label is heat-sealed to the outer peripheral surface of the peripheral wall, and in the second injection stage, the barrier resin is injected, and the bottom plate A method for producing a barrier plastic cup container, wherein a barrier resin layer is formed at an intermediate position of a base resin.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Next, the barrier plastic cup container manufactured by the embodiment of the manufacturing method of the barrier plastic cup container of the present invention will be described in detail with reference to the drawings. 1 (a) is a sectional view showing a structure of a barrier plastic cup containers this, (b) are enlarged cross-sectional view of the A portion.
[0008]
Barrier plastic cup container (100) This, as shown in FIG. 1 (a), a plastic cup container consisting peripheral wall (110) the bottom plate (120), the external shape, as shown in FIG. 1 ( In addition to the reverse cut right cone shown in a), there are a rectangular parallelepiped, a prism, a cut pyramid, a reverse cut pyramid, a right circular cylinder, a cut right cone, and the like. And as shown to Fig.1 (a), the barrier property in-mold label (111) is adhere | attached on the outer peripheral surface of a surrounding wall (110), and the barrier property resin layer (121) is attached to the intermediate | middle layer of a baseplate (120). It is provided. The container filled with the contents is covered with a barrier sealing film at the upper end of the container, and the outer peripheral edge of the sealing film is heat-sealed to the upper surface of the flange (130) at the upper end of the peripheral wall so as to be peeled off. The container is sealed. Alternatively, a lid is attached to the opening, and the lid is removably engaged with the flange at the upper end of the peripheral wall to seal the container.
[0009]
The method of manufacturing the barrier plastic cup container of the present embodiment described above includes an insert injection molding method and a multilayer injection molding method in which a main injection device and a sub injection device are connected to one mold and different resins are sequentially injected. It is what is used. In this molding method, in advance, a barrier in-mold label having a resin layer that is thermally fused to the back surface and bonded to the base material molding resin is formed on the cavity surface that forms the peripheral wall of the female mold of the injection mold. First, the gate position (G) at the center of the bottom surface of the bottom plate shown in FIGS. 1 (a) and 1 (b) by the main injection device in the first injection stage. A mold molding resin such as polypropylene and polyethylene is injected into the mold cavity (the space between the female mold and male mold where the molded product is molded) to form a peripheral wall, and at the same time, the outer peripheral surface of this peripheral wall has a barrier property The back side of the in-mold label is heat-sealed, and then in the second injection stage, a barrier resin such as ethylene / vinyl alcohol copolymer or nylon is injected into the mold cavity from the sub-injection device in time. Still on the bottom plate An intermediate position of the base resin in a melting state, thereby forming a barrier resin layer. Note that the base material molding resin injected into the mold cavity in the first injection stage is cooled by the mold from the mold cavity surface to the inside and further away from the gate position and solidifies sequentially. For this reason, the barrier resin injected in the second injection stage to the intermediate position of the base material molding resin cannot reach the intermediate position above the peripheral wall formed of the base material molding resin. For this reason, it is necessary to provide a barrier property to the peripheral wall by thermally fusing a barrier in-mold label to the outer peripheral surface of the peripheral wall. In addition, with normal equipment, a thickness of about 0.5 to 1.5 mm is optimal, and it is preferable to prepare a container with an internal volume of about 100 to 350 ml, but this is not limited if dedicated equipment is used. .
[0010]
The barrier plastic cup container manufactured in this embodiment described above is provided with a barrier property by a barrier in-mold label whose peripheral wall is heat-sealed to the outer peripheral surface, and the bottom plate is barriered by an intermediate barrier resin layer. Because of this, the barrier properties of the container as a whole are good, and the letters and designs that describe the product are printed on a label that is heat-sealed on the outer peripheral surface of the peripheral wall, so the design of the container Is good. Then, the container, because it is produced by injection molding, without uneven thickness, such as appearance properties good sheet forming the container, also expensive barrier resin, using only the intermediate layer of the bottom plate Therefore, the manufacturing cost is relatively low.
[0011]
【The invention's effect】
The barrier plastic cup container manufactured by the method for manufacturing a barrier plastic cup container of the present invention is a barrier resin layer that provides a barrier property to the peripheral wall with a barrier in-mold label that adheres to the outer peripheral surface to form an intermediate layer. The barrier property is imparted to the bottom plate, and the barrier property of the container is good.
[0012]
In addition, the characters and designs that convey product information are printed on a label adhered to the outer peripheral surface of the peripheral wall, so that the design is good, and the appearance is good because the container is manufactured by an injection molding method. without also relatively manufacturing cost is only being used in the intermediate layer of the bottom plate expensive barrier resin is inexpensive.
[0013]
Moreover, the barrier plastic cup container manufactured by the manufacturing method of the barrier plastic cup container of the present invention can be used for a heat sterilization method, and by using a barrier in-mold label that does not use an aluminum foil as a barrier layer. It can also be used for microwave ovens.
[Brief description of the drawings]
FIG. 1 (a) is a cross-sectional view showing the structure of a barrier plastic cup container manufactured in one embodiment of the present invention, and FIG. 1 (b) is an enlarged cross-sectional view of part A thereof.
FIG. 2 is a cross-sectional view showing the structure of an example of a conventional barrier plastic cup container.
[Explanation of symbols]
100 ... Barrier plastic cup container 110 ... Peripheral walls 111, 122 ... Barrier in-mold label 120 ... Bottom plate 121 ... Barrier resin layer 130 ... Flange G ... Gate position

Claims (1)

  In advance, a barrier in-mold label is inserted into the cavity surface forming the female peripheral wall of the injection mold, and in the first injection stage, the base material molding resin is injected into the mold cavity. At the same time, the barrier in-mold label is heat-sealed to the outer peripheral surface of the peripheral wall, and in the second injection stage, the barrier resin is injected into the mold cavity, and the middle of the base resin of the bottom plate The manufacturing method of the barrier plastic cup container characterized by having formed the barrier resin layer in the position.

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