HK1027076B - Beverage can lid and method of making - Google Patents

Description

Beverage container lid and method for manufacturing the same

Technical Field

The present invention relates generally to container closures for containers used to contain beverages or the like. In particular, the present invention relates to the construction of container caps and methods of making container caps.

Background

Known beverage containers have an upper end opening which is covered and sealed by a container lid. In this type of beverage container, after the inside of the container is sterilized to provide the container with a sterile state, the beverage is then filled into the container.

Conventional container lids for this type of container can be one of several different forms of container lids. One type of container lid is a so-called peelable seal type container lid, referred to herein as a membrane type container lid, which is made of a sheet material comprising a stretched polyethylene terephthalate (PET) film laminated on the surface of an aluminum foil, or the like, with an easily peelable material layer provided on the side of the laminate which is in contact with the container. The container lid is mounted over the open upper end of the container and is heat fused to the container by heating.

Another type of container lid includes a sheet covering the open upper end of the container. An opening is provided in the sheet to act as a drink aperture. The container lid has a pull tab constructed of a small piece of material made of PET/aluminum foil with an easy release layer adapted to cover the opening in the container lid.

Another type of formed container lid is made by drawing formed aluminum foil.

There is also a container lid prepared by a so-called insert injection molding method in which an aluminum foil is covered with Polyethylene (PE) or the like, such a sheet is previously inserted into a mold, and an opening device requiring opening of the container lid is provided in the aluminum foil, which is formed by injection molding.

However, the various container lid configurations described above have certain drawbacks or drawbacks. For example, in the above-described membrane type container lid, the sealing strength between the container lid and the container should be high enough to withstand various handling manners during the delivery of the product. On the other hand, the strength of the opening should be small enough to allow easy opening of the container, requiring removal of the container lid from the container. However, balancing the two requirements is quite difficult.

Further, since the opening formed after the container cover is taken out from the container is considerably large, the beverage is easily spilled in a certain case, for example, the beverage in the container is easily discharged from the container by drinking the beverage while walking.

In the case of the container lids described above having a pull tab, the problems described above are not generally related to membrane type container lids. However, because the pull tab is made from a membrane-type sheet material, the container lid does not provide a high quality appearance or appearance, but provides the user with the impression that the container lid has a rather "poor appearance".

A disadvantage of container lids made by stretch forming an aluminium foil is that they are rather expensive.

The last type of container lid, although using the viewpoint of providing gas barrier properties, has problems in that the process of coating polyethylene on aluminum foil is rather complicated and the container lid is easily peeled off.

In addition to the above, most of the above conventional container lids are removed from the container after the container is opened and separated from the container, so that there is a problem in how to handle them. Even when the container lid is opened without being detached from the container, the opened container cannot be sealed by the container lid according to the prior art.

Summary of The Invention

The object of the present invention is to solve the above disadvantages or drawbacks. The container lid of the present invention is designed to be able to withstand various handling methods during transportation, to be easily opened, to have good gas barrier properties, to have a high-quality appearance or profile, to be able to reseal the container once it is opened for use, and to be easily aseptically filled with beverages.

The container lid of the present invention is made of a thermoplastic resin material and is shaped to cover the open end of the container. The container cover includes a cover body provided with an opening for discharging contents of the container, and a pull cap provided on the opening. The pull-top has a lid portion for sealing the opening of the lid body and a pull tab portion connected to the lid portion with a gap between the periphery of the opening and the lid portion. The lid portion has an upper outer periphery provided with a projection for contact fitting with the periphery of the opening, and the lower surface of the lid body is covered with a gas barrier film.

According to another aspect of the present invention, a container lid covers an open upper end of a container, the container lid including a lid body and a pull cap. The lid body is provided with a through opening through which the contents in the container can be discharged. The gas barrier film is sealed to the lower surface of the lid body and extends across the opening of the lid body. The pull-top includes a lid portion and a pull tab portion that are connected to each other. The lid portion is sealed to the gas barrier film such that movement of the lid portion relative to the lid body causes the gas barrier film adjacent the periphery of the opening to tear, thereby exposing the opening of the lid body.

Another aspect of the invention relates to a method of making a container lid. The method of the present invention comprises inserting a gas barrier film into a cavity of a mold in an injection molding apparatus, injecting a thermoplastic resin material into the cavity to form a shape substantially identical to that of a container lid, opening the mold while keeping the molded article in a hot state, and taking out the molded article from the mold, and then, hot-press molding the periphery of the molded article.

Brief description of the drawings

Additional details of the structure and features of the present invention will become apparent by reference to the following detailed description of embodiments of the invention in which like elements are designated by like reference numerals throughout the drawings and wherein:

FIG. 1 is an exploded perspective view showing a container lid according to an embodiment of the present invention, in which the container lid is fixed to an opened upper end of a beverage container;

FIG. 2 is a side view of the container lid shown in FIG. 1;

FIG. 3 is an enlarged partial cross-sectional view of the container lid secured to the container as seen along section line 3-3 of FIG. 1;

FIG. 4 is a side view of a molded article obtained after the first stage of the process of the present invention has been carried out;

FIG. 5 is a side view of a molded article produced by continuously carrying out the first stage of the process of the present invention.

Detailed description of the invention

Referring first to fig. 1, in accordance with the present invention, a container 40 has an upper opening 41 adapted to be covered by a container lid 1. The container lid 1 includes a combination of a lid body 10 and a pull-top 20. In the illustrated embodiment, the cover 10 is circular, and a flange 12 is provided on the cover 10, the flange 12 constituting an outer peripheral portion of the cover 10. The flange 12 is adapted to be mounted to the upper end portion 42 of the container 40 such that the lid 10 extends across the open upper end 41 of the container 40. The lid body 10 further includes an opening 11, and the opening 11 serves as a drink hole or a discharge opening to remove the contents from the inside of the container 40.

The pull cap 20 comprises a cap portion 21, said cap portion 21 being adapted to seal the opening 11 in the lid body 10, and a pull tab portion 22 connected to the cap portion 21. The tab portion 22 and the lid portion 21 form an integral or unitary element.

As shown in fig. 1, the opening 11 in the cover 10 is of a fan or heart-shaped configuration. However, it is understood that the opening 11 may have other contour shapes. Of course, the lid portion 21 of the pull lid 20 has a shape corresponding to the opening 11 in the lid body 10.

Referring now to fig. 3, the pull cover 20 is secured in place with a gap 25 between the peripheral portion 14 of the cover body 10 surrounding the opening 11 and the outer periphery of the cover portion 21 in the container lid 1. Also preferably, the pull-tab portion 22 of the pull cap 20 is spaced from the upper surface of the lid body 10, as shown in FIG. 4.

The peripheral portion 14 of the opening 11 in the lid body 10 may have a desired cross-sectional shape, but it is preferable that its cross-sectional shape has a shape expanding or gradually expanding toward the container 40, as shown in fig. 3, so that the edge of the opening 11 has a triangular or beveled peripheral edge at which a closed upper edge is provided.

As best shown in fig. 3, the cap portion 21 includes an upstanding neck portion 27 and a bulge portion 29, the bulge portion 29 being located above the neck portion 27. The neck 27 has an outer peripheral surface from which the projections or protrusions 24 extend radially outwardly. The projections 24 are configured to engage the peripheral portion 14 of the opening 11 in a contacting manner, as will be described in more detail below.

As shown in fig. 3, the lower surface of the cover 10 is covered with a gas-barrier film 23, and the film 23 has a gas-barrier property, particularly, an oxygen-barrier property. The gas barrier film 23 extends across the opening 11 in the lid body 10 so that the gas barrier film 23 seals the interior of the container from the outside until the container lid is opened. Further, the end face of the neck portion 27 of the cap portion 21 is sealed to the gas barrier film 23. By moving the lid portion 21 of the lid 20 relative to the lid body 10, the connection between the lid portion 21 and the gas barrier film 23 is broken, thereby opening the opening 11 in the lid body 10 so that the gas barrier film is torn or broken along the periphery of the opening 11.

The container lid 1 of the present invention is advantageous in that it allows the container to be resealed after it is opened. In this regard, once the container is opened by removing the portion of the gas barrier film 23 covering the opening 11, the neck portion 27 of the cap portion 21 of the pull cap 20 is inserted into the opening 11 in the cap body 10 so that the protruding portion 24 of the cap portion 21 is in contact engagement with the peripheral portion 14 of the opening 11. The opening 11 is surrounded by the peripheral portion 14 of the lid body 10, and thus the peripheral portion 14 is sandwiched or disposed between the protrusion 24 of the lid portion 21 and the upper protruding portion 29. It is thus possible to seal the opening 11 during or after drinking the beverage.

The container lid 1 is preferably made of thermoplastic resin. Possible thermoplastic resins include: polyolefins, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), Polyamides (PA), Polystyrene (PS), polyvinyl chloride (PVC), ethylene vinyl alcohol copolymer resins (EVA), acrylonitrile butadiene styrene copolymer resins (ABS), methacrylic resins (PMA), Polycarbonates (PC), ionomers, cyclic olefin-olefin copolymer resins, and other particularly suitable materials.

Polyolefins that may be employed include Polyethylene (PE), e.g., low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, e.g., propylene homopolymer, ethylene-propylene random copolymer, ethylene-propylene block copolymer, polybutene-1, polyhexene-1, and polymethylpentene-1. These polyolefins may be used alone or in combination of two or three.

Of the above polyolefins, particularly preferred are polyethylene, polypropylene and mixtures thereof.

The gas barrier film 23, which forms part of the container lid 1, is made of a material having gas barrier properties, in particular oxygen barrier properties. Possible materials for the gas barrier film 23 are ethylene vinyl alcohol copolymer (EVOH), polyvinylidene chloride, and other materials. Ethylene-vinyl alcohol copolymers are preferably used. As the gas barrier film 23, the film may be made of one of the above-described materials. Further, a laminate of two or more layers of the material and another material may be used, and for example, a laminate may be formed using the above-described thermoplastic resin material.

A particular advantage is that for a gas barrier film 23 having a laminate construction in which the layer of material in contact with the lower surface of the lid body 10 in the laminate, i.e. the surface layer facing the interior of the container to which the lid is to be attached and secured to the container, is the same layer of material as the thermoplastic resin material from which the lid 1 is made, and therefore such a layer of material is readily melt-bondable to the lower surface in the construction of the lid 1 of the present invention. The laminated film is: polypropylene/ethylene vinyl alcohol copolymer/polypropylene (PP/EVOH/PP). Optionally, an adhesive layer is disposed between the resins.

The thickness of the gas barrier film 23 is at least a minimum thickness to meet the requirement of preventing gas from penetrating the film during the time the beverage is filled into the container and until the container is opened. Thus, the film has a suitable thickness, which may depend on the type of beverage and/or the method of handling the container.

According to the present invention, the container lid 1 having the above-described structure is mounted on the container 40, and after the beverage is filled into the container 40, the flange 12 of the lid body 10 is mounted and sealed to the upper portion 42 of the container 40. The container 40 is then typically sterilized.

To drink or discharge the beverage from the container 40, it is necessary to lift the lid portion 21 of the lid 20 upward, which remains covering the opening 11 since the gas barrier film is not affected. That is, as described above, in a preferred embodiment, the gas barrier film 23 or the laminate of the gas barrier film 23 is located on the side of the container lid 1, wherein the material of the film layer is the same as that of the container lid 1. Since the adhesive strength between the lid portion 21 and the gas barrier film 23 is very good, the lid portion 21 will be separated from the gas barrier film 23 when the lid portion 21 is pulled upward, and there is only a small change in the lid portion 21. In addition, it is alternatively possible to tear the gas barrier film 23 along the periphery of the opening 11 of the lid body 10 when the lid portion 21 is pulled upward, thereby opening or unsealing the opening 11, by enhancing the adhesive strength between the lid portion 21 and the gas barrier film 23.

Further, the opening 11 can also be opened or opened by pushing down the lid portion 21 of the lid 20 on the lid body 10. This will tear the gas barrier film 23 along the periphery of the opening 11 or create a tensile stress locally in the gas barrier film 23 along the peripheral portion 14 around the opening 11. Then, the tab portion 22 is pulled upward, and the lid portion 21 to which the torn portion of the gas barrier film 23 is fixed is removed.

As described above, after the container is opened, the opening 11 can be resealed by inserting the lid portion 21 of the flip top 20 into the opening 11 such that the outwardly extending projections 24 engage in contact with the peripheral portion 14. In the lid body 10, the peripheral portion 14 around the opening 11 is located between the projection 24 of the lid portion 21 and the projection 29 thereon.

According to the present invention, the method for manufacturing the container lid 1 described above preferably comprises the steps of: first, the gas barrier film 23 is prepared and inserted into a mold cavity in an injection molding apparatus. Secondly, heat-melting as a molding material of the thermoplastic resin of the container lid 1, and thirdly, injecting the heat-melted thermoplastic resin material into a cavity of a mold in an injection molding apparatus to form a molded article which is heat-melted and bonded integrally with the film, which is a partial molded article or a preform, as shown in fig. 4.

Cooling the mold while maintaining the partial form or preform in a hot state, opening the mold, and removing the partial form or preform therefrom. In this case, it is important to maintain the heat in the molded object while removing the partially molded object or preform from the mold, because it is difficult to release the tab portion 22 constituting the pull cap 20 from the mold in the container lid after the molded object is cured.

After the partial molding or preform shown in fig. 4 is taken out from the injection molding apparatus, it is subjected to hot molding so that the flat outer edge 15 forms the flange 12 as shown in fig. 2, thereby constituting the container lid 1 of the present invention.

The present invention also allows the production of the above-described topographies or preforms by means of a long gas barrier film 23, as shown in fig. 5. By using such a continuous molding method, the manufacturing process capability of the container lid can be greatly improved.

By means of the invention, a number of advantages can be achieved. In one aspect, the container lid according to the present invention has sufficient strength to withstand various handling forms during product transportation, and also has excellent gas barrier properties. Also, since the gas barrier film 23 is provided on the inner layer, this film can be relatively thin. Thus, only a small force is required to break or peel the film 23 and thereby open the container.

Furthermore, when the beverage in the container is only partially consumed or drained, the opening can be reclosed using the pull-off cap removed before that. This allows the remaining beverage to be easily preserved and the container to be easily carried without the risk of the beverage spilling out of the container.

Also, when the beverage is completely consumed from the container, or emptied, the container needs to be discarded, and the container and the pull-top can be put together by inserting or fitting the pull-top into the opening.

The container lid can have a high quality appearance and is convenient for sterilization after filling with the beverage.

Also, since the gas barrier film can be molded simultaneously with the injection molding of the container lid body, the manufacturing cost of such a container lid can be considerably reduced as compared with a container lid body molded by hot-melt adhesion of the gas barrier film.

In the foregoing specification, the principles, preferred embodiments and processing methods of the present invention have been described in detail. However, the invention as claimed is not limited to the specific embodiments described above. The above examples are illustrative of the present invention and are not to be construed as limiting. Many other variations and modifications and other equivalent forms can be made without departing from the spirit of the invention. Therefore, all changes or modifications that come within the spirit and scope of the invention, or equivalents thereof, are intended to be embraced by the claims.

Claims (3)

1. A method of manufacturing a container lid secured to a container, comprising: performing a continuous molding process to produce a continuous molded article, and bonding the continuous molded article with a long gas barrier film by heat fusion, including providing the long gas barrier film into a mold cavity in an injection molding apparatus; injecting a thermoplastic resin material into the cavity to form a continuous molded article, the molded article being thermally melt-bonded to the elongate gas barrier film, each molded article comprising a lid body provided with an opening and a lower surface sealed to the elongate gas barrier film, and a pull cap having a cap portion and a pull tab portion, the cap portion and the pull tab portion being connected to each other, the cap portion being disposed relative to the opening so that a gap exists between a periphery of the opening of the lid body and the cap portion, the cap portion having an outer periphery on which a protrusion is provided so that, after the opening is opened, the protrusion is fitted into the opening to reclose the opening; opening the mold while the molded article is in a hot state; then, the molded article is taken out of the mold.

2. The method for manufacturing a container lid according to claim 1, wherein: the molded article has a perimeter and includes the step of thermoforming the perimeter of the molded article after the molded article is removed from the mold.

3. The method for manufacturing a container lid according to claim 1, wherein: the step of thermoforming the periphery of the molded article comprises forming a flange at the periphery of the molded article to enable the container lid to be mounted to the open upper end of the container.