JPH04114872A - Sealing of glass container, and cap - Google Patents

Abstract

PURPOSE:To permit a glass container to be sealed by a method wherein the opening of a container is capped with a resealable plastic cap, which is then covered with the laminated cap consisting of the synthetic resin having adhesiveness toward the glass and aluminum foil to heat seal them. CONSTITUTION:A plastic cap 2 is inserted into a glass container from an opening part 5 thereof until the cap flange makes a close contact with the top panel of the glass container and a laminated cap is inserted into close contact with a plastic cap, after which a synthetic resin layer having adhesiveness toward the glass around the peripheral part of the container opening is heat melted and a sealing is made in a manner wherein the peripheral part of the glass container opening and aluminum foil are heat bonded into a seal part 4 without contaminating the plastic cap. To unseal the container, an unsealing tab 3 is pulled up to remove the laminated cap and open the plastic cap so as to take out its contents. If one wants to recap the container temporarily, it can be sealed easily with the plastic cap.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for sealing a glass container that is tamper-evident, recappable, and has excellent sealability, and an aluminum foil laminated cap used therein.

[Prior Art] Coupled with recent changes in containers and foods, various types of closures have been introduced onto the market. Consumers require closures to have sealing properties that reliably preserve the contents of the containers until they are opened, and functionality that allows the contents to be safely and easily taken out as needed.

On the other hand, from the manufacturer's side, it is important to not only fully meet consumer needs, but also to be inexpensive, withstand temperature changes and external forces in the product production line, to be compatible with automated sealing, and to ensure that the contents remain intact before reaching the consumer. , especially retention of carbon dioxide gas, etc.
In addition, closures are required to maintain vacuum and have barrier properties against oxygen, moisture, aroma components, etc., and closures are being developed depending on the type of contents and usage conditions.

Since the mid-1960s, special aluminum foil tear-off caps have been added to glass containers.
Cup-shaped containers that combine (:ap) are on the market, and products containing sake, juice, wine, jelly, etc. can be easily carried around due to the spread of vending machines, and the easy-open design allows for easy opening anywhere. Its production is steadily expanding due to its characteristics such as the ability to easily take out the contents.

This type of sealing method requires a corrosion-resistant coating because the inner surface of the cap comes into contact with the contents, and this coating does not peel or crack even when clipped during sealing, does not damage the contents, and does not contaminate the contents. It needs to be something that does not happen.

Since contact between aluminum foil and glass makes sealing impossible, the use of a sealant is required. In this case, it would be preferable to use a gasket made of inexpensive foamable plastic, but since this gasket has poor elasticity, it is necessary to use an expensive plastisol compound to achieve a complete seal.

In addition, with this method, when the container is sealed, the pressure inside the container is reduced, even if only slightly, so when removing the cap, excessive force is often applied, causing the contents to spill.6 [Problems to be Solved by the Invention] ] The present invention does not use expensive plastisol compounds,
The purpose is to develop a sealing method that uses an inexpensive plastic cap, is easy to open, can be recapped, and has excellent sealing performance, and an aluminum foil laminated cap for use in this method, while also improving the characteristics of conventional tear-off caps. Easy opening, tambour-epitect nature (Tam
The purpose of this research is to develop a capping material for glass containers with perEvident) and a sealing method for the same.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a resealable plastic cap at the mouth of a glass container, and a synthetic resin adhesive that is adhesive to the glass. and an aluminum foil laminated cap formed to match the shape of the mouth of the glass container so that the resin layer is on the inside, and the cap and the glass container are sealed by heat sealing. To provide a method for sealing a glass container.

Furthermore, a heat seal suitable for this method of sealing glass containers is made by molding a laminate of synthetic resin and aluminum foil that is adhesive to glass so that the resin layer is on the inside to match the shape of the mouth of the glass container. We have developed and provide an aluminum foil laminated cap that seals with

In the present invention, the target glass container is not a conventional glass container with a spirally carved opening on an outer cap, but it is sufficient to include a simple ordinary wide-mouth glass container, such as a cup-shaped container, A feature of the present invention is that it can be applied to such glass containers.

It is relatively elastic for a plastic cap,
A material that does not contaminate the contents or be attacked by the contents, such as polyethylene, polypropylene, vinyl chloride, etc., is used. Although the shape is not particularly limited, as shown in Figure 1, most have a brim with an outer diameter the size of the top surface of the mouth of the container or slightly smaller than that, and a glittering pattern on the inside diameter of the mouth of the container. Preferably, it consists of pillars that fit together and form a seal. This is because it is necessary to fit it into a container filled with contents, apply a load from the top, and bring the bottom surface of the brim into close contact with the top surface of the container mouth.

This plastic cap is used as a cap when recapping the bottle after opening it.

The thickness of the aluminum foil may be thinner than the tear-off cap of a normal cup-shaped glass container, and it varies depending on the diameter of the glass container, the contents, etc., but generally it is 30 to 1 OO1.
, Lm, preferably about 80 LLm.

Synthetic resins used for the synthetic resin layer that is adhesive to glass include heat-fusible ionomers, polyethylene, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, and unsaturated materials such as maleic anhydride. Polyolefin resins modified with carboxylic acid or mixtures of these resins and wax, which are called hot melts, can be used.

The thickness of these resin layers is 30 to 150 μm, preferably 50 to 70 μm. If this resin layer is too thin, heat sealing will not be successful, and if it is too thick, the effect will not improve.

The method of laminating these two layers is not particularly limited, and the method of laminating the aluminum foil may be directly extrusion coated with a resin layer, or a single layer film may be made from the resin and laminated by dry lamination, etc. The lamination method does not matter.

Furthermore, the opposite side of the resin layer of the aluminum foil can be freely coated with an overcoat for printing and protecting the printing.

Such a laminate is punched out and formed into an aluminum foil laminate cap by drawing to match the maximum diameter of the mouth of the glass container.

At this time, it is convenient to open the bottle by adding an opening knob6.You can also put a score vertically on the skirt.

As for the sealing method, a plastic cap is attached to a glass container filled with the contents, a laminated cap is placed on the container, and the container is heat-sealed to the mouth of the glass container. The location of the heat seal is the peripheral edge of the mouth of the glass container, and its outline is as shown in FIG.

As described above, in the method of the present invention, the plastic cap is completely sealed, but the plastic cap is sealed by heat sealing to prevent it from loosening due to internal pressure, etc., and to provide a tamper-evident seal. However, when heat-sealing the laminated cap, it is also possible to crimp the skirt to the mouth of the glass container, thereby making the seal even more secure.

Hereinafter, the present invention will be specifically explained with reference to the drawings.

Place a plastic cap (2) on the mouth (5) of the glass container.
), and then insert the laminated cap (1) until it touches the top of the plastic cap, and then add a layer of synthetic resin that is adhesive to the glass around the rim of the container mouth. This is a method of sealing by heat-melting and heat-melting the aluminum foil to the peripheral edge of the mouth of the glass container so as not to attach it to the plastic cap (4).

When opening the container, the laminated cap can be removed by pulling up the opening knob (3), and the contents can be taken out by opening the plastic cap.

However, when it is desired to temporarily keep the cap on, there is the advantage that it can be easily sealed by plugging it with a plastic cap.

[Function] In the method of the present invention, by using a resealable plastic cap and an aluminum foil laminated cap in combination, a synthetic resin cap with tamper-evident properties can be created regardless of the shape of the opening of the glass container. This was achieved by heat sealing.

Aluminum foil laminated caps, which are made by laminating aluminum foil and a synthetic resin that is adhesive to glass, can be easily manufactured by deep drawing the aluminum foil laminate; It will be impossible to remove it until it is wet. In particular, when clipping is performed, the seal is double-sealed because it is heat-sealed, and the plastic cap also becomes sealed without loosening.

[Example] (Example 1) Dumilan C-1552 (Takeda Pharmaceutical Company Limited) 5 was printed and overcoated on 80 μm thick aluminum foil.
A 0 μm film was laminated using a two-component urethane adhesive, and the laminated material was punched out to fit the cap of a pot-shaped glass container (capacity 1, 80 m 12 ) with a diameter (outer diameter) of 57 mm, and drawn using a press. , a cap with a skirt length of 7 mm.

Fill the container with water, fit a cap made of low-density polyethylene, cover with an aluminum foil laminated cap, and heat seal the skirt of the cap to the glass container at 220°C for 1 second while applying a load to the top surface. I did it.

The sealed container was left horizontally at 45°C ± 2°C for 24 hours to check for leakage of the contents (water) based on the test method specified in Ministry of Health and Welfare Notification No. 20. As a result, no water leakage was found in any of the 30 samples.

(Example 2) The thickness of the aluminum foil was 50 μm, and instead of Dumilan, the thickness of Himilan 1.702 (Takeda Pharmaceutical Company Limited) was 5 μm.
A cap similar to Example 1 was manufactured except that the thickness was 0 μm.

Similarly, a water leakage test was conducted using 30 samples, and there was no water leakage at all, and the sealing performance was good.6 [Effects of the invention] The glass container has a beautiful appearance, and also has a good shelf life for the contents. Due to its transparency as a container and relatively high mechanical strength, it is widely used as a container for beverages such as carbonated drinks, soft drinks such as juice, dairy products such as yogurt and milk, alcoholic beverages, soy sauce and food oil. 6 In recent years, tear-off caps, maxi caps, and the like have been used as closures that have tamper-evident properties.

These caps are opened by cutting an aluminum shell with a score engraved along the score, so a considerable amount of force is required to open the cap.
Also, depending on how much force is applied, the contents sometimes spill out.

The present invention uses a plastic cap as the inner plug,
By using an aluminum foil laminated cap for the outer column and heat-sealing the laminated cap, we provided a method for easily sealing the mouth of the glass container without limiting the shape of the mouth.

When using this method, the bottle can be opened without much force, and when the bottle has been opened, it is clearly visible and it is impossible to reseal it. In addition, the plastic cap provides a good seal, and the tongue is pressed with a heat seal to ensure a high degree of sealing. Furthermore, it can be recapped using a plastic cap, which is also an advantage.

Moreover, since the sealing is done by simply heat sealing the plastic cap fitter and the laminated cap, this sealing method is fully compatible with the increased speed of automatic container filling machines.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of a cross section of the mouth of a glass container sealed by the method of the present invention. 1. Aluminum foil laminated cap 2, plastic cap 3, opening knob 4, heat seal part 5 Glass container mouth Patent applicant Showa Aluminum Co., Ltd. Agent
Patent Attorney Sei Kikuchi

Claims (5)

[Claims] (1) Put a resealable plastic cap on the mouth of the glass container, and place a laminate of synthetic resin and aluminum foil that is adhesive to glass on top of it to match the shape of the mouth of the glass container. A method for sealing a glass container, which comprises covering the container with an aluminum foil laminated cap formed with the resin layer on the inside, and heat-sealing the cap and the glass container. (2) The method for sealing a glass container according to claim 1, wherein heat sealing is performed on the skirt portion of the aluminum foil laminated cap and the peripheral edge of the mouth of the glass container. (3) The method for sealing a glass container according to claims 1 and 2, which comprises heat sealing using an aluminum foil cap and clipping the cap when sealing the glass container. (4) A laminate of synthetic resin and aluminum foil that is adhesive to glass is molded to fit the shape of the mouth of the glass container so that the resin layer is on the inside, and the aluminum foil laminate is sealed by heat sealing. cap. (5) The aluminum foil laminated cap according to claim 4, wherein the aluminum foil laminated cap is provided with a knob for opening.