Cover unit with adapter, cover, and sealing film for a container

Abstract

The invention relates to a cover unit (10) for closing and sealing a container (1). The opening (9) is surrounded by a sealing edge (8). The cover unit has an adapter (11), a cover (12), and a sealing film (13). The adapter can be arranged on the container in the opening thereof or around said opening so as to leave the sealing edge exposed, and the adapter has a through-opening (22). The cover is removably arranged on the adapter. The sealing film is clamped between the cover and the adapter so as to cover the through-opening. The invention also relates to a container with such a cover unit and to a method for sealingly closing a container.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]The present application is a U.S. national stage application under 35 U.S.C. §371 of International Application No. PCT / EP2013 / 051007, filed Jan. 21, 2013, which claims priority to German Patent Application No. 102012100483.8, filed Jan. 20, 2012, and German Patent Application No. 102012209597.7, filed Jun. 6, 2012, the entireties of which are incorporated herein by reference.FIELD OF DISCLOSURE[0002]The present invention relates to a cover unit for closing and sealing an opening, which is surrounded by a sealing edge, of a container such as a can, barrel or the like, to a container closed using a cover unit according to the invention and having an opening surrounded by a sealing edge, and to a method for sealingly closing a container of this type.BACKGROUND[0003]Containers are known from the art in which an end-face opening is closed and sealed using a membrane. On the container, in the opening thereof, a metal ring is generally attached ...

AI Technical Summary

Benefits of technology

[0005]Starting from the above-described prior art, the object of the invention is to provide a cover unit and a method for closing and sealing a container by means thereof which are material-efficient, can be produced / carried out on simple, conventional machines, and can be used for various commercially conventional containers and covers without adapting them to the invention. In particular, the cover unit is to be supplied as a pre-assembled unit to a filler of a corresponding container, and, after filling with the filling material, should be able to be arranged and sealed on the container by said filler in a simple, rapid and inexpensive manner using simple, conventional machines.

[0010]The sealing film and the container are the only units which come into contact with the filling material. The cover and the adapter can therefore consist of virtually any desired materials, irrespective of the filling material. In this way, cost-effective and simple materials can be used for the cover and adapter, whilst potentially high-grade materials which are adapted to the filling material need only be used for the container and the sealing film, for example materials suitable for food. The use of these expensive high-grade materials can thus be reduced. Preferably, the cover and / or adapter consist in whole or in part of plastics material. The adapter may in particular be in the form of an injection-molded plastics material element. As a result, the loss of material described in the prior art from punching out a metal ring for sealing film attachment can be prevented. The adapter is produced in a simple, cost-effective manner, for example injection-molded, in the respectively required shape.

[0012]The cover is preferably arranged on the adapter using a thread or a bayonet joint. As a result, the cover can be opened and reclosed in a simple manner by an end-user, in particular after the container is filled and closed. Further, it can be arranged on the adapter using a determined, defined contact pressure, in such a way that the sealing film is clamped in place and fixed sufficiently for sealing onto the sealing edge. It is advantageous for the cover to have some resilience at least in part, for example in the region of the end-face cover face thereof, since in this case the sealing film can be reliably held by way of a degree of yielding when it is placed on or screwed onto the adapter and the resulting resilient restoring force. According to the invention, a resilient intermediate layer which performs this resilient function can be laid in the cover on the adapter side between the sealing film and the cover.

[0016]To make it easier to slide the adapter onto the container, in a further inventive proposal said adapter comprises a ramp, preferably in the form of a shoulder extending in the radial and axial directions. This can lie against the shoulder of the container wall when the adapter is slid on.

[0018]In one embodiment of the invention, an anti-twist device is provided for the cover unit with respect to the container. This may in principle be implemented in a positive, non-positive or material fit. In particular, at least one catch structure may be arranged or formed in the region of the container wall on which the adapter is arranged, especially in the region of the depression between the flanged edge and the shoulder. This may in particular project radially outwards, for example in the form of a cam profile or a weld seam. When the cover unit is arranged on the container, the catch elements of the catch structure on the container cooperate in a positive fit and bring about anti-twist protection of the cover unit on the container. In this context, the catch structure on the container and the catch elements of the adapter engage in one another in the radial direction and thus prevent the cover unit from twisting with respect to the container. In another form of the invention, the anti-twist protection can be achieved in that the annular wall of the adapter is formed as an interference fit assembly or by means of a press fit with respect to the container wall, in particular with respect to the container wall on the side of the shoulder opposite the flanged edge. Finally, the adapter may with respect to the container by means of an adhesive or hot adhesive, in particular in the aforementioned region. This adhesion may be used as an alternative or in addition to the two twist protections by positive and non-positive fit. Twist protection of this type ensures that the cover can be removed from and arranged back on the container by the user in a simple and reliable manner, in such a way that the container can be opened and reclosed without difficulty.

[0021]It is particularly preferred for the sealing edge and sealing film to be heated and sealed by induction, preferably by passing under a surface induction coil. As a result of the invention, advantageously only the material of the sealing film has to be heated to a sufficient temperature for the sealing. It is not necessary to apply an additional contact pressure to the container provided with the cover unit. The contact pressure on the sealing edge exerted on the sealing film by the cover and adapter is sufficient for the sealing, and so the device required for sealing the container can advantageously be particularly simple in construction and cost-effective. It is sufficient simply to pass the container provided with the cover unit under an induction coil and merely to ensure sufficient heating.

Problems solved by technology

One problem with containers or sealing systems of this type is that during the manufacture of the metal ring a considerable proportion of the material used is wasted.

The metal ring is produced by punching it out from a metal sheet, and so the sheet material punched out to form the internal recess becomes waste, which is inefficient, environmentally unfriendly and cost-intensive.

However, the system requires relatively high investment in facilities and machines, and attaching and sealing the sealing membrane to the generally curved inner wall of the container is generally not without difficulties in terms of manufacture, for example as a result of weld seams in the wall.

A further problematic aspect is that the sealing foil is attached to the inner container wall using an adhesive material.

Therefore, after a user removes the sealing film, material residues may disadvantageously remain on the inner wall of the container and in particular in the region of the opening edge thereof.

Also, 100% tight sealing of the container is generally not possible, and so it is only suitable for dry filling material.

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