JP3723534B2 - Beverage container lid and injection molding method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lid for a resin beverage container, and more particularly to a lid having a notch for a straw insertion slot and a method for forming the lid.
[0002]
[Prior art]
As a method for injection molding a thin film body having a through hole, there has been a method described in JP-A-2002-225087 .
[0003]
[Problems to be solved by the invention]
In a container for packaging a beverage enclosing living bacteria such as lactic acid bacteria, it is necessary to seal the opening of the container with a sealing material so that air does not flow in. And the container which enclosed the said drink is often sold by covering a resin lid on the opening part sealed with the sealing material. When drinking a beverage whose opening is sealed with such a sealing material, a means is often adopted in which the sealing material is pierced with a straw with a sharp tip attached, and drinking with the straw. In this case, in order to save the trouble of taking a resin lid placed on the sealing material, a straw insertion slot cutout may be provided in the resin lid. By pushing and bending the cut portion with a straw, the straw is made to penetrate the resin lid.
[0004]
A method for forming a lid having such a slit insertion slot cut portion has been conventionally formed by sheet molding rather than injection molding. At the same time as forming the sheet, the cutting portion for the straw insertion port was provided by the blade.
[0005]
In this respect, injection molding rather than sheet molding is advantageous in terms of cost. This is because once the mold is made, mass production can be easily performed. Nonetheless, the reason why the sheet molding was performed is that, according to the injection molding, the mold part for providing the notch for the straw insertion port becomes thin, so when the heat-melted resin is injected into the mold, the above-mentioned This is because the mold portion corresponding to the cut portion may be bent or broken in some cases.
[0006]
Accordingly, the present invention provides an injection molding method capable of producing a lid for a beverage container having a notch for a straw insertion port while being injection molded, and a beverage container lid produced by the injection molding method. The purpose is to provide.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention comprises a male mold having a cylindrical protrusion and a female mold having a recess corresponding to the protrusion, and a cavity is formed between the two by clamping the mold. Use injection molds. The male mold is provided with a ridge for forming a cut portion on the cylindrical projection, and the female mold corresponds to the ridge and allows molten metal to pass between the ridge 12. A recessed groove having a possible gap was provided. A molten metal, which is a resin heated and melted through a gate and a runner, is injected into the mold, and the molded body is taken out after cooling.
[0008]
The reason why a lid having a slit insertion slot can not be formed by injection molding is that the mold part for providing a straw insertion slot is thin, so the molten metal, which is heated and melted, is used as a mold. This is because the mold portion corresponding to the cut portion may be bent or broken in some cases when injected into the inside.
[0009]
In the present invention, the mold portion corresponding to the cut portion corresponds to a protrusion provided on the male mold. However, in the present invention, the female mold is provided with a groove corresponding to the protrusion and having a gap between the protrusion 12 and allowing the molten metal to pass therethrough . This concave groove becomes the escape route of the molten metal, and excessive pressure is not applied to the ridge. In this way, in the present invention, even when the molten metal that is heat-melted resin is injected into the mold, it is possible to prevent the mold portion corresponding to the cut portion from being bent or broken.
[0010]
In other words, it is possible to produce a lid for a beverage container having a straw insertion slot cutout by an injection molding method.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the present invention will be described below with reference to the drawings.
[0012]
FIG. 1 is a use state diagram of a lid according to the present invention, FIG. 2 is a perspective view schematically showing a male mold, and FIG. 3 is a perspective view schematically showing a female mold. 4 is a schematic cross-sectional view of a mold according to the present invention.
[0013]
As shown in FIG. 1, the lid 40 according to the present invention is provided with a cut portion 41. The cut portion 41 is pushed and bent with a straw, and further, the sealing material 60 covering the opening of the beverage container 50 is pierced and drunk.
[0014]
The metal mold | die concerning this invention is comprised from the male metal mold | die 10 which has the protrusion 11 and the protruding item | line 12, and the female metal mold | die 20 which has the recessed part 21 and the recessed groove 22 as shown in FIG. By clamping the male mold 10 and the female mold 20, a cavity 30 is formed between them.
[0015]
In FIG. 4, the gate 13 is provided in the male mold 10, but may be provided in the female mold 20.
[0016]
As shown in FIG. 2, the male mold 10 has a columnar projection 11 and a ridge 12 provided on the projection 11.
[0017]
The gate 13 leads to the runner of the extruder and is used for introducing the molten metal into the cavity.
[0018]
As shown in FIG. 3, the female mold 20 has a concave portion 21, and a concave groove 22 is provided in the concave portion 21. The groove 22 is provided at a position corresponding to the ridge 12 provided on the male mold 10 when the mold is clamped and having a gap through which the molten metal can pass between the ridge 12 .
[0019]
【The invention's effect】
Since the present invention is configured as described above, it is produced by an injection molding method capable of creating a lid for a beverage container having a notch for a straw insertion port while being injection molded, and the injection molding method. It is possible to provide a lid for a beverage container.
[Brief description of the drawings]
FIG. 1 is a diagram showing a use state of a lid according to the present invention.
FIG. 2 is a perspective view schematically showing a male mold.
FIG. 3 is a perspective view schematically showing a female mold.
FIG. 4 is a schematic cross-sectional view of a mold according to the present invention.
[Explanation of symbols]
10 ... male die 11 ... projection 12 ... projections 13 ... gate 20 ... female die 21 ... recess 22 ... groove 30 ... cavity 40 ... lid 41 ... cut section

Claims (2)

  A lid for a beverage container comprising a male mold 10 having a columnar projection 11 and a female mold 20 having a recess 21 corresponding to the projection 11, and a cavity 30 is formed between the two by clamping the mold. An injection mold for molding, which is provided with a ridge 12 for forming a notch 41 provided on the lid 40 on the columnar protrusion 11 and corresponds to the ridge 12 on the female mold 20. In addition, the molten metal is injected through a gate and a runner into a mold provided with a groove 22 having a gap through which the molten metal can pass between the ridges 12, and the molded body is taken out after cooling. A method for injection molding a lid for a beverage container.   A lid for a beverage container having a slit insertion slot formed by the injection molding method according to claim 1.

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