DE9307844U1 - Assembled snap-on lid and its attachment to food containers - Google Patents

Description

Description:

Assembled snap-on lid and its attachment to food containers.
Technical area:

Slip lids are used to seal solid, liquid and gaseous substances in a container from the outside. They separate substances from one another with their surface. An example of such separation is the slip lid according to the invention, which is made up of two parts (l)/(2) and is both a vacuum pump and a tamper-evident seal.

State of the art:

Snap-on lids are used in a variety of designs and attachments on food containers; as overlids on containers sealed/welded with foil, in order to be able to close the container again after removing the foil so that no coarse foreign bodies can get inside, furthermore as partially permeable closures for containers for self-preserving substances or for containers that can be hermetically sealed with a twist closure: for example after filling the warmed and sterile food into the sterile container without adding preservatives.

The effect of the latter approach is that when metal snap-on lids are used as twist-lock closures, snapping noises are produced when opening, namely when, as intended, the contents of the vessel are under a negative overpressure compared to the outside.

Such a snapping noise, caused by the metal lid springing back, is often indicated by the suppliers of such twist closures as a sign of the first opening and thus as a tamper-evident seal.

This behavior has not been known to date with plastic snap-on lids. The invention is intended to remedy this situation, _so that a display of this kind is now possible for the purchaser of foodstuffs - achieved without additional effort. In previous designs, labels are welded, glued or otherwise attached to the snap-on lids without using them as reinforcement and/or control membranes, for example for the gas exchange between the inside and outside of the container, as described in G 92 14 374.1 and now according to the invention.

Description of the invention:

The composite slip-on lid consists of the lid (1) and the label (2), which acts as a reinforcement and/or control membrane according to the description in G 92 14 374.1 of October 26, 1992, published in the patent gazette of February 4, 1993, designation of the object: composite slip-on membrane _f . Taking into account the rigidity of the label, the lid is designed in such a way that it can be elastically deformed on its inner part (d' up to 1"") and has a vacuum-generating effect.

The rounded annular groove (1") sloping from the inside from the upper edge of the lid (I ¹ ) and the adjoining elevation (I ¹ " ) facing the upper outer edge of the lid (I ¹ ) and then sloping into a depression (1"") in the direction of the annular groove (1") results in a vertical section in profile ^ ^Fi 9,-l)j through the axis (1""'), a wave-shaped cross-section (bet, _r X") which allows movement of the inner part towards the vessel (3) to an extent not previously known.
As a result, with the lid (1) attached and the label (2) connected to it and adapted to its shape, a lift of a previously unknown extent towards the vessel (3) can be achieved and at the same time a vacuum can be created. This lift of the assembled slip lid towards the interior of the vessel (3) can be designed in such a way that a large part of the remaining volume, after the vessel (3) has been filled, is filled by pressing in the inner part of the assembled slip lid (1)/(2). The medium displaced from the vessel in this way (for example air) escapes between the sealing lip (1""") of the lid (1) and the vessel rim ( ³¹ ).

This is possible because the lid edge (i ¹¹¹¹ " ¹ ) is elastic. The then released composite slip lid (l)/(2) returns to its position before pressing in until it reaches a previously defined equilibrium position between external and internal forces on the composite slip lid (l)/(2) and thereby generates a predeterminable negative overpressure in the now covered vessel (l)/(2)/(3). The size of the negative overpressure is due to the

The choice of wall thickness of the lid (Cl) and label (2), the choice of material and the shape of the assembled snap-on lid (l)/(2) as well as the extent of the deformation due to forces from inside and outside on it can be determined. This ability to determine the negative overpressure in the closed container (l)/(2)/(3) enables automated packaging of yoghurt, for example, simply by placing the assembled snap-on lid on the container (3), here a cup, and the negative overpressure generated at the same time when it is placed on it holds the assembled snap-on lid on it. The generation of the negative overpressure can also take place when a hot filling material and the heated medium above it cool down when the container is closed.

Furthermore, to generate the negative overpressure, a heated medium can be fed into the remaining space above the filling material without the filling material having to be heated, as this is made possible by the fact that when the medium cools down, it contracts when the assembled slip-on lid is in place.

The negative overpressure is maintained in the case of the composite slip lid according to the invention even during gas exchange by the regulating property of the membrane effect according to the composite slip membrane according to the invention and its attachment to food containers according to G 92 14 374.1 of October 26, 1992, since a state of equilibrium with regard to the negative overpressure is established accordingly _/ during an osmotic process. This is an advantage of the composite slip lid according to the invention compared to an impermeable metal lid such as that used up to now with the twist closure. The composite slip lid allows gas exchange for the first time while maintaining a negative overpressure - and this in a regulated manner - so that biological processes can now take place in the closed container (3), important for example in the case of cream cheese, without the holding force of the composite slip lid on the container being changed or the container contents being able to absorb microorganisms from the outside. Even with a constant pressure difference between

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When the container is closed, the inside and outside of the container retain the shape of the assembled snap-on lid (l)/(2) and thus indicate that the container has not been opened. This is a visible means of ensuring authenticity and is not yet known. In addition, when the container is opened, a hissing sound is produced which, like the snapping sound when a known twist cap is opened, can be interpreted as a sign of the original filling of the contents. An elastic crown, which a assembled snap-on membrane according to G 92 14 374.1 has to press onto a sealing surface on the container and hold it there, is not required for the assembled snap-on lid, as the edge of the latter is designed in such a way that when placed on the container, it wraps around the edge of the container and sucks itself onto it.

The form-fitting tamper-evident seal according to G 92 14 374.1 can also be dispensed with, which results in a further reduction in the cost of the vessel closure through the composite slip lid.
Both parts, the container and the lid (1), are now reusable, which further contributes to the price reduction. According to the invention, the label (2) is destroyed when opened to indicate that the opening has taken place. The label (2) is therefore preferably attached to the lid (1) by means of an adhesive connection, the ratio of the lid surface to the unglued lid surface allowing a wide range of adjustment from sterile closure behavior to highly breathable closure behavior, as already mentioned on page 1, lines 14 to 24 of the claims in G 92 14 374.1.

So far, tests have been carried out with polymers such as polyurethane, polypropylene, polyethylene and styrene-acrylonitrile for the lid (1), the container (3) and the label (2). All of these materials tested fulfilled the requirements placed on them in terms of food safety, elasticity, dimensional stability and hygiene and in particular their behavior as membrane parts for the lid (Cl) and label (2) of the assembled snap-on lid (l)/(2) and tamper-evident security. However, materials other than polymers are also possible, for example modified natural materials such as cardboard/paper.

Other cross-sectional shapes of the lid (l) and the label connected to it are also possible to generate the necessary large stroke to create the vacuum in the closed vessel (l)/(2)/(3). For example, the description only mentioned one version of the assembled snap-on lid (l)/(2) and three options for its attachment using the vacuum created in the closed vessel (d)/(2)/3) when it is put on and its wrapping behavior according to the utility model G 92 07218.6.

This wrapping, described for a Bscherdackel as the form elements of a conical "tube" around a conical "thorn", is now being used for the first time in a vacuum closure and here in a new type of slip-on lid.

A further design of the lid (1) is a flat, vertically positioned inner lid side or a slightly profiled lid inner part design when using appropriately elastic lid/label and/or container materials such as polyurethane or high molecular weight low-pressure polyethylene or any other usable material combination for lid (1), label (2) and container (3). A different form of sealing seat than in G 92 14 374.1 or G 92 07218.6 between lid (1) and container (3) is also possible, for example the container edge is then cylindrical or flared outwards in a cup shape and the lid sealing edge is adapted to this.

Commercial applicability:

The lid, designed as a vacuum seal, can be used for a variety of food containers where the contents must be kept sterile.

The assembled snap-on lid (l)/(2) can be sterilized after use after removing the label (2) and can then be reused.
Because only the label (2) needs to be recycled, but the lid (1) is fully functional again after a new label (2) has been applied, considerable amounts of waste are avoided while maintaining hygiene when such a closure is used again.

Claims (1)

-1- Claims: !.Composite slip lid and its fastening on food containers which comprises a container edge (3 ¹ ) with a sealing lip (1""") and according to the system described in the utility model G 92 07 218.6, "thorn" wrapped in a "hose", creates a seal between the sealing lip (1""") of the lid edge (i"" ¹¹¹ ) _and the container edge (3 ¹ ) and is additionally held on the container (3) by a negative overpressure, characterized in that it consists of a lid (1) and a label (2) which, in their interaction, reinforce and ensure the tamper-evident nature of the closure.
2.Composite slip lid according to claim 1, characterized in that the label (2) acts as a control membrane for the gas exchange between the outside and the inside of a vessel (3). 3.Composite slip lid according to claim 1, characterized in that the label provides tamper-evident protection. 4.Composite slip lid according to claim 1, characterized in that the lid (1) and label (2) are connected to one another in such a way that after detaching the label (2) from the lid (1) and sterilizing the lid (1), the lid (1) can be reused. 5.Composite slip lid according to claim 1, characterized in that the lid (1) alone or with the label (2) acts as a vacuum pump when placed on the container (3). 6. Assembled slip lid according to claim 1, characterized in that the lid (1) acts as an tamper-evident seal. 7.Composite slip lid according to claim 1, characterized in that the lid (1) together with the label (2) acts as a composite control membrane for gas exchange between the inside and outside of a vessel sealed with it (3).