JPH05254545A - Intermediate for easily openable cap and method for production thereof - Google Patents

Abstract

PURPOSE:To easily obtain an intermediate for easily openable cap by a method wherein a bottomed hollow cylindrical body having the flange provided with notches in a radial manner is formed of a laminated product having an air permeation preventing layer and the edges of each notch are overlapped. CONSTITUTION:A laminated body having a gas permeation preventing layer 7 and adhesive layers 8a and 8b is stamped into a circular pressing larger than the core of a press molding metal die and this circular product is provided with notches 9 around its circumferential edge oriented toward the center thereof. The edges of the notch 9 forms an angle of 0 degree or more. This circular laminated product 5 is placed in the press molding metal die and a hollow column-like side wall 14, a bottom part 15 and a flange part 13 are formed by the die core. The edges of each notch 9 are overlapped on the flange part 13 to form an overlapping part 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has a gas permeation preventive property for an easily openable plastic cap used for a container for filling juices, other beverages, desserts, foods such as prepared foods, and other contents. The present invention relates to an intermediate provided for giving and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, a plastic cap having an easy-open property has a tab for opening the plastic cap that is easy to open in consideration of distribution and transportation of the container when fitting and bonding with the container. It is convenient to place it one step lower than the top surface (upper end). This is the packaging,
This is because if the tabs project from the top surface in the stacking, there is a problem of damage or difficulty in stacking.

For this reason, it is necessary to process the easily openable plastic cap with a gas permeation preventive layer for imparting gas permeation preventive property to a shape conforming to the easily openable plastic cap. Has been used.

As a method of manufacturing an intermediate for an easily-openable cap, a laminated body having a synthetic resin layer having thermal adhesiveness on the front and back sides of a gas permeation preventive layer is punched into a circular shape, and this is simply pressed into a pair of concave and convex. After placing it on the concave cavity of the mold, press it with a convex core while holding it with a disk-shaped fixing jig, or apply heat adhesion to the front and back of the gas permeation preventive layer. A method in which a laminate provided with the synthetic resin layer is punched into a circular shape, directly placed in an injection molding die, and an intermediate body is manufactured by clamping is used. Further, as a post-process, in both the methods of (1) and (2), an easily openable plastic cap having a gas permeation-preventing property was obtained by placing it in an injection mold and then injecting a molten resin.

However, when the press working is carried out by the method (1), the end of the laminated body to be worked is not fixed and stress is exerted even in the free state, so that the press workability is poor, The gas permeation preventive layer may be stretched, compressed, or bent over a wide area to cause cracks in the gas permeation preventive layer.

Due to the curl, there is a problem in that when the laminate is not kept in a flat state, press working causes misalignment. Further, when the press working is performed by the manufacturing method of (3), the press workability is poor, and wrinkles and corrugations occur at the tip of the intermediate body, that is, the flange, and in a subsequent process, the molten resin in the injection mold is injected. , It became a cause of hindering the resin flow when integrated with the intermediate.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides an easy-open cap intermediate having a gas permeation preventive layer which is easy to manufacture and has no problem, and a method for manufacturing the same. The challenge is to provide.

[0008]

In order to solve the above problems, the present invention provides a resin layer having thermal adhesiveness on both sides of a gas permeation preventive layer in a cavity of an injection molding die.
After inserting and holding the preformed intermediate for the easy-open cap, injection molding the thermoplastic resin, and used for the manufacture of the easy-open cap provided with the wall for fitting the container, the flange, and the opening tab. In the preformed easily-openable cap intermediate body, the intermediate body is hollow and has a columnar side wall and a bottom portion, and a plurality of eaves-shaped flange portions are cut in the center direction at the columnar side wall upper end, The cut part is preformed by forming an intermediate for the easy-opening cap next to each other and a resin layer having thermal adhesiveness on both sides of the gas permeation preventive layer in the cavity of the injection molding die. Insert an easy-to-open cap intermediate,
After holding, the thermoplastic resin is injection-molded to obtain the preformed easy-open cap intermediate used for producing the easy-open cap provided with the container fitting wall surface, the flange portion, and the opening tab. In the manufacturing method, a core having a pair of protrusions and depressions of a press-molding die is punched into a shape larger than the core, and a plate-like object having a notch or notch on the periphery is held, and then the core is larger than the core. Moving the core into a cavity having a concave shape,
It is a method for producing an easily-openable cap intermediate body in which the plate-like material is slid into a gap between the core and the cavity and preformed.

A more preferable layer structure of the gas permeation preventive laminate is a laminate of at least three layers, the laminate has a thickness of 25 μm or more, and the gas permeation preventive layer has a thickness of 15 μm or more. Occupy.

A method for producing an easily-openable cap using the present intermediate body is to transfer the present intermediate body into an injection molding die and injection-mold a thermoplastic resin to form a wall surface for fitting a container, a flange portion, Opening tab and cross section V for the purpose of assisting openability
Providing a half-cut part with a letter shape.

Alternatively, the easily-openable cap can be obtained by another manufacturing method in which the cap body, the side wall surface for fitting the container, the flange portion, and the opening tab are attached to the laminate at the same time as molding.

A detailed description will be given below with reference to the drawings. FIG. 1 is a perspective view illustrating a manufacturing process of an intermediate body of the present invention. 2 and 10 are perspective views of the preform-processed intermediate body of the present invention. Depending on the shape of the container, the intermediate
Various shapes are conceivable, but for convenience of explanation, a circular shape will be mainly described. 7 and 12 are plan views showing an embodiment of an easily-openable cap using the intermediate body of the present invention. Figure 3
FIG. 4 is a cross-sectional view showing an example of a laminate 5 having a gas permeation preventive layer used in the present invention, which comprises a gas permeation preventive layer 7 and adhesive layers 8a and 8b.

FIGS. 4, 5 and 11 are plan views showing a state in which the cut 9 is provided in the laminated body 5 having the gas permeation preventive layer used in the present invention. FIG. 6 shows the intermediate 12 of the present invention.
FIG. 9 is a cross-sectional explanatory view showing an example of an easily-openable cap using, and FIG. 8 shows a state in which the container 18 is fitted and adhered with the easily-openable cap molded using the intermediate 12 of the present invention. FIG. It includes an easily-openable cap 1, an outer peripheral portion 2 which is a wall surface for fitting a container, a cap body 3, an opening tab 4, an intermediate body 12 made of a laminated body 5 having a gas permeation preventive layer, and a half cut portion 6. FIG. 9 shows A of the intermediate 12 of FIG.
FIG. 4B is a cross-sectional view taken along line A-A, showing how the overlapping portions 16 overlap.

The gas permeation preventive layer 7 shown in FIG.
It may be a soft or hard metal foil such as aluminum having a thickness of 5 μm or more.

The adhesive layer 8a in the laminate 5 is used when adhering to the container after filling the contents, and as the material, when the material of the container is polypropylene resin, the adhesive layer 8a is used. Polypropylene resin, ethylene-vinyl acetate copolymer or the like can be used as the material. When the container is made of polyethylene resin, the adhesive layer 8a may be made of polyethylene resin or ethylene-vinyl acetate copolymer. When the container is made of polyester resin, the adhesive layer 8a is used.
Polyester resin, ethylene-vinyl acetate copolymer, or the like can be used as the material. When the container is made of a polyamide resin or a vinyl chloride resin, the adhesive layer 8a can be made of ethylene-vinyl acetate copolymer or the like.

On the other hand, the film forming method of the adhesive layer 8a may be a well-known T-die type film, or an unstretched, uniaxially or biaxially stretched film having a thickness of 5 μm or more formed by an inflation method.

The adhesive layer 8b on the upper surface of the intermediate body 12 is used for thermally bonding the constituent members of the easily-openable lid body made of a thermoplastic resin, that is, the container fitting wall surface, the flange portion and the opening tab. The film may be a non-stretched, uniaxially or biaxially stretched film having a thickness of 5 μm or more formed by a well-known T-die type or an inflation method.

As for the material, when the material of the constituent member of the easy-open lid is polypropylene resin, the material of the adhesive layer 8b is polypropylene resin or ethylene-vinyl acetate copolymer. Can be used. When the material of the constituent member of the easy-open lid is polyethylene resin, the material of the adhesive layer 8b may be polyethylene resin, ethylene-vinyl acetate copolymer, or the like. When the material of the constituent member of the easy-open lid is a polyester resin, the material of the adhesive layer 8b may be polyester resin, ethylene-vinyl acetate copolymer, or the like. When the material of the constituent member of the easy-open lid is a polyamide resin, the adhesive layer 8
As the material of b, an ethylene-vinyl acetate copolymer or the like can be used.

The gas permeation preventive layer 7 and the adhesive layers 8a and 8b may be adhered by a known extrusion laminating method or dry laminating method.

In the manufacturing process of the intermediate body 12, as shown in FIG. 1, the core 10 having the convex portions of the pair of concave and convex press molding dies.
Then, after punching the laminated body 5 into a constant shape larger than the core 10, a notch 9 is radially formed in a constant length in the circumferential direction.
Are placed at a plurality of locations (preferably at eight locations or more) and processed into the shape shown in FIG. 4 or FIG. The opening angle of the notch 9 may be 0 degrees or more, and the maximum angle is the intermediate body 12.
Shape, that is, the dimensions of the flange portion 13 and the side wall portion 14, and
Depending on the number of cuts to be provided, when the diameter of the intermediate body 12 is about 90 mm, the cut 9 is formed so that the overlapping portion 16 of the laminated body in the flange portion 13 is about 2 mm or less.
It is desirable to set the angle of each time. Overlap part 16
If the width is too wide, the adhesive force is insufficient when fitting with the container, and a gap is created, resulting in liquid leakage. Further, if the width of the overlapping portion 16 is narrow, the gas will permeate.

After that, after holding the laminated body 5 which has been subjected to the notch processing in the core 10, the laminated body 5 is moved into the cavity 11 having a shape larger than the core 10 and having a concave portion. Is slid into the gap between the core 10 and the cavity 11 to preform the laminated body 5 into a shape corresponding to the cavity of the injection molding die, and the intermediate body 12 having the flange portion 13, the side wall portion 14, and the bottom portion 15 is formed. To get

[0022]

The intermediate body according to the present invention has a hollow columnar side wall and a bottom portion, and a plurality of eave-shaped flange portions are cut in the center direction at the upper end of the columnar side wall, and the cut portions are adjacent to each other. Therefore, when the molten resin in the injection molding die is injected and integrated with the intermediate body in the subsequent process, the flange portion is wrinkled and wavy, and does not impede the flow of the resin and is uniform over the entire surface. It is possible to manufacture an easily-openable cap 1 having a three-dimensional shape having a gas permeation preventive layer.

In addition, in the method for producing an intermediate according to the present invention, a core having a convex portion of a pair of concave and convex press molding dies,
After punching into a shape larger than the core and holding a plate-shaped object having a notch on the peripheral edge, the core is moved into a cavity having a shape larger than the core and having a recess, By pre-sliding by slipping into the cavity of the cavity, the intermediate can be easily obtained without being partially stretched, contracted or wrinkled.

In the present invention, the adhesive layer 8a is provided for the purpose of adhering the easily-openable cap and the container after filling the contents. Further, the adhesive layer 8b is provided in order to bond the gas permeation preventive layer 7 to the outer peripheral portion 2 serving as the container fitting wall surface and the cap body 3 simultaneously with molding. The thickness of the gas permeation preventive layer 7 prevents the permeation of the intended gas, so that the combination of the material and the thickness as described above exerts an effect.

[0025]

【Example】

<Example 1> From a homopolymer polypropylene resin in which a soft aluminum foil having a thickness of 50 μm is used as the gas permeation preventive layer 7 and a melt index of 1.0 is formed by extrusion molding on both surfaces of the aluminum foil by an inflation molding method. An unstretched polypropylene film having a thickness of 25 μm is laminated by a dry lamination method using a two-liquid reaction type polyester adhesive, adhesive layers 8a and 8b are provided, and a gas permeation preventive layer having a thickness of 100 μm is laminated. Body 5
Got

The laminated body 5 having the gas permeation preventive layer is
After punching into a circular shape with a diameter of 90 mm, the opening angle is 42.5
32 cuts having a length of 10.5 mm were provided at 32 positions.
Next, before performing the drawing process in the pair of concave and convex press forming dies, the outer diameter of the press forming die having the convex portion 78.
A 1 mm core 10 is driven horizontally, and the laminated body 5 processed as described above is moved down so that the core 10 and the center of the laminated body 5 coincide with each other.
After sucking air from 7 and holding it in the core 10, the core 10 is raised and returned to the position before driving. Thereafter, the core 10 holding the laminated body 5 is lowered and moved into a cavity 11 having an inner diameter of 78.4 mm and a depth of 4.0 mm having a concave portion of a press molding die, and the laminated body 5 is called the core 10. The laminated body 5 is preformed into a shape corresponding to the cavity of the injection molding die by sliding it into the gap of the cavity 11 and raising the core 10 to raise the vacuum port 17
The suction of air from the
An intermediate body 12 having 4, a bottom portion 15, and a polymerization portion 16 was obtained.

Next, the intermediate body 12 is set to have an inner diameter of 78.6 mm.
After being inserted into the cavity of the injection molding die and then fixed, and after the die is closed, the outer peripheral portion 2, the cap body 3, and the opening tab 4 are provided in the absence of the injection die cavity.
Was injection-molded with polypropylene resin so as to be attached to the intermediate body 12 at the same time as molding.

At this time, by using a ring-shaped protrusion provided in the cavity on the side where these are mounted and having a V-shaped cross section, a groove effective at opening is formed on the outer peripheral portion 2.
The half-cut portion 6 was formed at the boundary between the cap body 3 and the cap body 3 so as to have a V-shaped cross-section. The polypropylene resin used was a homopolymer having a melt index of 20.0 and 50% calcium carbonate having a particle size of 0.1 μm added thereto.

[0029]

As described above, according to the present invention, the laminated body 5 can be simply and accurately placed on the press molding die, and the gas permeation preventive layer is free from wrinkles and cracks. It is possible to easily obtain a stable intermediate. Also,
Inserting the intermediate into a mold of injection molding or other molding method to form the remaining parts constituting the easy-open cap, attaching to the intermediate, and processing for easy opening. It was made possible to manufacture a three-dimensional easy-opening cap having a gas permeation-blocking property by applying all of the above.

[0030]

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a manufacturing process of an intermediate body of the present invention.

FIG. 2 is a perspective view of a polyfoam processed intermediate body according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing an example of a laminate 5 having a gas permeation preventive layer used in the present invention.

FIG. 4 is a plan view of an example showing a notch formed in a laminate 5 having a gas permeation preventive layer used in the present invention.

FIG. 5 is a plan view of an example showing a notch formed in a laminate 5 having a gas permeation preventive layer used in the present invention.

FIG. 6 is a cross-sectional view showing an example of an easily-openable cap using the intermediate body of the present invention.

FIG. 7 is a plan view showing an example of an easily-openable cap using the intermediate body of the present invention.

FIG. 8 is a cross-sectional view showing a state in which a container is fitted and bonded with an easily-openable cap molded using the intermediate body according to the present invention.

9 is a sectional view taken along line AA of the intermediate body 5 shown in FIG.

FIG. 10 is a perspective view of a polyfoam processed intermediate body according to an embodiment of the present invention.

FIG. 11 is a plan view of an example showing a notch formed in a laminate 5 having a gas permeation preventive layer used in the present invention.

FIG. 12 is a plan view showing an example of an easily-openable cap using the intermediate body of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Easy-opening cap 2 ... Outer peripheral part 3 ... Cap main body 4 ... Opening tab 5 ... Laminated body 6 ... Half cut part
7 ... Gas Permeation Prevention Layer 8a ... Adhesive Layer 8b ... Adhesive Layer 9 ... Notch 10 ... Core 11 ... Cavity 12
... Intermediate 13 ... Flange 14 ... Side wall part 15 ... Bottom part 16 ... Polymerization part 17 ... Vacuum port 18 ... Container

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location // B29L 22:00 4F

Claims (2)

[Claims] 1. A preformed easy-to-open cap intermediate body having a resin layer having thermal adhesiveness on both sides of a gas permeation preventive layer is inserted and held in a cavity of an injection molding die. In the preformed easily-openable cap intermediate used for manufacturing an easily-openable cap having a wall surface for fitting a container, a flange portion, and a tab for opening provided by injection molding a thermoplastic resin, The body is hollow and has a column-shaped side wall and a bottom portion, and at the upper end of the column-shaped side wall, a plurality of eaves-shaped flange portions are cut in the center direction, and the cut portions are adjacent to each other and easily opened. Intermediate for sex cap. 2. A preformed pre-openable cap intermediate body having a resin layer having thermal adhesiveness on both sides of a gas permeation preventive layer is inserted into a cavity of an injection molding die.
After holding, the thermoplastic resin is injection-molded to obtain the preformed easy-open cap intermediate used for producing the easy-open cap provided with the container fitting wall surface, the flange portion, and the opening tab. In the manufacturing method, a core having a pair of protrusions and depressions of a press-molding die is punched into a shape larger than the core, and a plate-like material having a notch on the periphery is held, and then a shape larger than the core is used. A method for producing an easily-openable cap intermediate, comprising moving the core into a cavity having a recess and sliding the plate into a gap between the core and the cavity for preforming.