JP4416424B2 - Plastic cap - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plastic cap, and more particularly to a plastic cap that can be pierced with a straw in the top plate portion of the cap and can drink a beverage in the container through the straw without removing the cap from the container mouth.
[0002]
[Prior art]
Conventionally, there has been known a cap that allows a beverage in a container to be drinked without piercing the top plate portion of the cap with a straw and removing the cap from the container mouth portion. Describes a cap in which a circular sedimentation portion is formed on the top surface of the top plate portion of the cap, and a breakable line is formed in the sedimentation portion to allow a straw to be inserted therethrough. In such a cap, it is of course possible to remove the cap from the container mouth and consume the beverage in the container.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-205756 [Patent Document 2]
Japanese Patent Laid-Open No. 2002-255203
[Problems to be solved by the invention]
Although the cap described in the said patent document can consume the drink in a container using a straw, without removing a cap from a container opening part, in these caps, it is formed in the top plate part. In order to enable the breakable line to be easily broken using a straw, it is necessary to form the cap from a synthetic resin that is relatively soft and has low mechanical strength.
However, when a cap is formed from a synthetic resin that is relatively soft and has a low mechanical strength, the strength of the cap becomes insufficient, and there is a tendency to be inferior in drop resistance and impact resistance. On the other hand, if the cap is made of a synthetic resin that is relatively hard and has high mechanical strength in order to make the cap sufficiently strong, in addition to being difficult to break with a straw in the breakable line, the container mouth If the seal portion that is in close contact with the portion is also integrally formed, the sealing characteristics may be insufficient.
[0005]
Accordingly, an object of the present invention is to provide a cap that can be easily perforated by a straw while having strength and sealing performance as the cap.
Another object of the present invention is to provide a cap that can be integrally molded while being a combination of different materials and has excellent moldability.
[0006]
[Means for Solving the Problems]
According to the present invention, in a plastic cap comprising a cap shell comprising a top plate portion and a skirt portion depending from the top plate portion, and a liner formed to cover the inner surface of the cap shell top plate portion, the top plate portion of the cap shell has an opening. And the liner comprises a relatively thick outer annular portion and a pierceable thin portion located inside and corresponding to the opening from the outer annular portion, and the liner corresponding to the opening. There is provided a plastic cap characterized in that a protrusion is formed at substantially the center on the outer surface side , and that the cap shell and the liner are formed by integral molding.
In the plastic cap of the present invention,
1. The liner is integrally formed by compression molding in the cap shell,
2. The thickness of thin-walled liner which corresponds to the open mouth portion toward the center from the opening edge,
Is preferred.
[0007]
In the plastic cap of the present invention, by forming the cap shell and the portion where the straw is to be perforated from different materials, it is possible to perforate with a straw very easily while having strength as a cap. Moreover, since the cap shell and liner are molded by integral molding, there is no need for assembly and setting processes, and the moldability is excellent, and there is no gap between the cap shell and the liner, especially for aseptic filling. When applied, it has an excellent effect such that the bactericide does not remain in the gap.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
1A and 1B are diagrams showing an example of a plastic cap of the present invention, where FIG. 1A is a top view and FIG. 1B is a side sectional view. 2 is a view showing a state in which a straw is inserted into the plastic cap shown in FIG. 1. FIG. 2A is a top view, FIG. 2B is a side sectional view of the left half, and a side view of the right half.
The cap of the present invention, indicated as a whole by 1, consists essentially of a cap shell 2 and a liner 20.
The cap shell 2 includes a top plate portion 3 and a skirt portion 4 depending from the periphery of the top plate portion 3, and an opening 5 is formed at the center of the top plate portion 3. The skirt portion 4 is formed with a screw portion 6 for screwing with the screw portion 31 of the container mouth portion 30, and a tamper evidence band 8 is provided below the skirt portion via a breakable weakening portion 7. Is formed.
[0009]
An annular protrusion 9 is formed on the outer peripheral side of the inner surface of the top plate portion 3, and a liner 20 is formed at a portion defined by the annular protrusion 9. An inner annular protrusion 21 and an outer annular protrusion 22 are formed on the liner 20, and an annular portion 23 defined by the inner annular protrusion 21 and the outer annular protrusion 22 is relatively thick. The sealing property of the cap is ensured by the contact of 30. The inner annular protrusion 21 is located on the outer peripheral side of the edge portion 10 of the opening 5 of the cap shell. In the specific example shown in the figure, the liner 24 inside the inner annular protrusion 21 is formed relatively thin. The cap shell opening 5 is covered with a thin liner 24, and the liquid-tightness of the container before being pierced by the straw 40 is maintained.
[0010]
In the embodiment shown in FIG. 1, a cross-shaped protrusion 25 is formed at the center portion on the outer surface side of the liner 24 in the opening 5. Since the projection 25 is formed at the center of the thin liner 24 in the opening 5, the tip of the straw 40 is locked to the projection 25 when the thin liner 24 is drilled by the straw 40. The tip of the straw 40 does not slide on the liner, and the straw 40 can be easily pierced near the center of the liner 24.
The shape of the protrusion is not limited to the cross shape as shown in FIG. 1, and any straight line, curved line, or a combination thereof, or any shape such as a circle or a triangle can be used as long as the end of the straw can be held at the position to be drilled. The shape can be adopted.
[0011]
A portion of the liner corresponding to the hole in which the straw 40 is perforated is not cut off and is pushed into the container on the outer peripheral surface of the straw 40, so that the liner is not accidentally swallowed. Further, since the liner 24 is pushed in, a gap is formed between the outer peripheral surface of the straw 40 and the liner 24, and this gap has a function of an air hole, so that the contents can be sucked smoothly by the straw. It becomes possible to do. In particular, when the protrusion 25 is provided at the center of the liner 24, the gap becomes large, so that smoother suction is possible.
[0012]
Of course, if the cap 1 is rotated and removed from the container mouth 30, the contents can be taken out directly from the container mouth 30. In this case, by rotating the cap 1 up, the tamper evidence band 8 can be removed. Since the flap piece 11 provided on the inner surface side engages with the annular protrusion 32 of the container mouth portion 30, the weakened portion 7 is broken, and the tamper evidence band 8 remains on the container mouth portion 30 side. It is clearly stated that
[0013]
The plastic cap of the present invention is limited to the specific examples shown in FIGS. 1 and 2 as long as it has an opening at the center of the top plate of the cap shell and a thin portion is formed on the liner corresponding to the opening. It is not something. For example, when the liner 24 corresponding to the opening 5 of the cap shell 2 becomes thinner from the opening peripheral edge 10 toward the center as shown in FIG. 3, the straw is brought into contact with the liner 24 corresponding to the opening 5. Then, since the tip of the straw slides toward the thinnest central portion 26, the center of the liner 24 at the opening can be easily perforated.
Moreover, various aspects, such as providing a protrusion as shown in FIG. 1 at the center of the liner that becomes thinner from the periphery of the opening toward the center as shown in FIG. 3, can be employed.
Furthermore, the thin portion provided in the liner corresponding to the opening is not limited to the entire opening or the vicinity of the center of the opening. For example, a thin portion is provided near the opening edge, and the thin wall is aligned with the straw at the opening edge of the cap shell. A straw can be drilled in the part.
[0014]
According to the two-color molding or the like, the plastic cap of the present invention can simultaneously perform the molding of the cap shell, the molding of the liner, and the setting of the liner into the cap shell. Also, the molding and setting of the liner can be simultaneously performed by molding the cap shell by compression molding or injection molding first, and by compressing the liner forming resin using the cap shell as a part of the compression molding die.
[0015]
In the plastic of the present invention, it is preferable to use a synthetic resin excellent in mechanical strength such as drop resistance and impact resistance for the cap shell, but not limited to this, it is preferable to use polypropylene, high density polyethylene or the like. .
On the other hand, a liner that can be thermoformed among conventionally known liner materials such as olefin rubber, thermoplastic elastomer, and low density polyethylene can be used. Most preferably, low density polyethylene can be used.
[0016]
In addition, in order to allow the liner to be easily perforated by a straw and to prevent the liner from being unexpectedly broken, the thickness of the thin portion provided in the liner corresponding to the cap shell opening is determined depending on the liner material and straw used. Generally, it is preferably in the range of 0.2 to 0.4 mm, although it varies depending on the material and shape of the material.
In addition, the size (diameter) of the opening provided in the cap shell top plate portion varies depending on the size of the straw used for drilling, but when a straw having a diameter of about 4 to 8 mm is used, the diameter of the top plate portion of the cap shell. Preferably, it is in the range of 35 to 55%. If it is larger than the above range, there is a high possibility that the liner of the opening will break unexpectedly due to impact or the like. On the other hand, if it is smaller than the above range, drilling with a straw may be difficult.
[0017]
【The invention's effect】
According to the plastic cap of the present invention, the top plate of the cap shell comprises: a cap shell comprising a top plate portion and a skirt portion depending from the top plate portion; and a plastic cap comprising a liner formed so as to cover the entire inner surface of the cap shell top plate portion. An opening is provided in the part, and the liner corresponding to the opening has a thin-walled part, and the cap shell and the liner are formed by integral molding, so that the strength and sealing as a cap can be achieved. In addition, it is possible to provide a cap that is easy to perforate with a straw and can be integrally molded and has excellent moldability.
[Brief description of the drawings]
1A and 1B are views showing an example of a cap of the present invention, in which FIG. 1A is a top view and FIG. 1B is a sectional side view of FIG.
FIG. 2 is a view showing a state in which the cap shown in FIG. 1 is applied to the container mouth and a straw is inserted, in which (A) is a top view, (B) is a left side cross-sectional view, and the right half is It is a side view.
FIG. 3 is a side sectional view showing another example of the cap of the present invention.
[Explanation of symbols]
1 cap, 2 cap shell, 3 top plate, 4 skirt,
5 opening, 9 annular protrusion, 10 opening periphery, 20 liner,
21 inner annular protrusion, 22 outer annular protrusion, 23 annular portion,
24 Opening liner, 25 protrusion, 30 container mouth, 40 straw.

Claims (3)

In a plastic cap comprising a cap shell comprising a top plate portion and a skirt portion depending from the top plate portion, and a liner formed so as to cover the inner surface of the cap shell top plate portion;
An opening is provided in the top plate portion of the cap shell, and the liner is composed of a relatively thick outer annular portion and a pierceable thin portion located inside and corresponding to the opening of the outer annular portion, A plastic cap characterized in that a protrusion is formed at substantially the center of the outer surface side of the liner corresponding to the opening , and the cap shell and the liner are formed by integral molding.   The cap according to claim 1, wherein the liner is integrally formed by compression molding in a cap shell. The cap according to claim 1 or 2, wherein a thickness of the liner corresponding to the opening becomes thinner from the periphery of the opening toward the center.

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