EP2032460A1

EP2032460A1 - Sealing insert for container closures

Info

Publication number: EP2032460A1
Application number: EP07765516A
Authority: EP
Inventors: Peter Rothweiler
Original assignee: Alfelder Kunststoffwerke Herm Meyer GmbH
Current assignee: Alfelder Kunststoffwerke Herm Meyer GmbH
Priority date: 2006-06-28
Filing date: 2007-06-20
Publication date: 2009-03-11
Also published as: AU2007263837B2; AU2007263837A1; WO2008000673A1; NZ573370A; US20100009162A1

Abstract

The invention relates to a sealing insert for container closures, comprising a support layer (10), a transparent lamination film (20) and an adhesive layer (30) joining the lamination film (20) to the support layer (10). The adhesive layer (30) has a different light/dark value and/or a different colour than the support layer (10). The adhesive layer, in particular, is coloured.

Description

Sealing insert for container closures

The invention relates to a sealing insert for container closures, with a carrier layer, with a transparent laminating film, and with an adhesive layer connecting the laminating film with the carrier layer.

Sealing inserts for container closures often consist of foamed polyethylene or foamed polypropylene. These sealing inserts are disc-shaped and usually round, so in total they form a cylindrical disc. As such, they are already a product available on the market.

As a rule, this product consists only of a homogeneous material. However, this gasket can also be used as a carrier for a more complex product. The disc of foamed polyethylene or foamed polypropylene then forms a carrier layer. In addition to the carrier layer, which has a heat-insulating, insulating and sealing function and is also able to compensate for certain manufacturing tolerances due to its foam-like consistency, the sealing inserts are often given a further material property. Thus, it is desired that certain barrier properties also exist, for example in the form of oxygen or water vapor barrier. Certain mechanical properties such as sliding properties or a further mechanical sealing function are desired. To achieve this, the carrier layers are provided with a corresponding laminating film.

This laminating film is also referred to as a barrier film. It is adhesively bonded by means of an adhesive, for example a polyolefin, to the foam of the carrier layer. This adhesive is usually hot to aid in the attachment process of the liner to the backing. One can therefore call the bonding process in a sense as a welding process. The main component of the sealing insert is therefore a carrier layer, as a rule a foam-extruded, white layer. The on laminated foil is transparent. These are, for example, polyethylene films which are used here for lamination. The foam-extruded carrier layer and the laminating film are glued together and then the desired sealing disks are punched out of the resulting overall web.

In the case of a white carrier layer, each individual sealing disk looks white from both sides, since the laminating film is clear and transparent. Other dyeings of the laminating film would in principle be possible, which is also desired in practice. For example, the users of sealing disks would be interested in adapting the sealing disk to the color of the product to be packaged, for example by providing orange juice with container closures which, on the inside, look orange to the viewer.

In quite a different context, it has already been proposed in the relatively old documents FR 1 558 341 and US Pat. No. 2,620,939 to provide one side of sealing disks with a different color than the other side of these sealing disks. Based on this color could then be an orientation of the sealing discs when inserting.

These older documents, however, do not deal with sealing discs mt one-sided laminating film, as described above, and give no indication of details.

In practice, however, the desire for colored laminated sealing inserts fails because a coloring of the transparent polyethylene film is possible, but would be very expensive. The production facilities for such polyethylene films would have to be converted for this purpose to add color pigments in the production, and they would have to be retooled, and then return to the production of the desired for all other applications, clear transparent polyethylene films. Since the number of required sealing inserts for container closures is very large, the area required in each case, however, is very large. ring, production of colored transparent polyethylene films is not profitable for this one purpose of a particular customer or uneconomically expensive for this customer.

A coloring of the carrier layer in the foam extrusion process while retaining clear, transparent laminating films would also be physically possible. Again, however, there would be the problem that the Schaumextru- sionsanlagen would have to be converted very expensive and time-consuming in each case to add a specific color to the foam. A very thorough cleaning of the foam extrusion equipment as well as a returning conversion would then also be required.

For this reason, this desire, which has been expressed by users, has not been met, or only rarely, by special cases justifying high conversion costs.

The object of the invention is in contrast to propose a more economical way to be able to offer users sealing inserts for container closures that cause a colored or at least not purely white impression in the viewer.

This object is achieved with a sealing insert for container closures, with a carrier layer, with a transparent lamination film, and with an adhesive layer connecting the lamination film with the carrier layer, wherein the adhesive layer has a different light / dark value and / or a different color than the carrier layer.

The invention makes use of the knowledge that such a sealing insert for container closures does not only consist of the two essential components carrier layer on the one hand and laminating film on the other hand, which are present both as the only constituents of the manufacturers of sealing inserts and the users.

In addition, however, there is the largely unnoticed adhesive layer, with just these two essential components are connected together. These Adhesive layer is quantitatively compared to the other components of the sealing insert negligible and it is also also between the other two components and thus in a covered space that does not impose optical effects.

Here, however, the case is given that the laminating film is clear and transparent, so that a viewer can see through them on the carrier layer. However, between the laminating film and the carrier layer is just the adhesive layer, so that an inventive, preferably colored adhesive layer for the viewer acts as if the entire sealing insert provided with a color.

The adhesive layer now has the additional advantage that it is inserted only in the final production and assembly of the sealing insert from the two main components and is available for a variable and targeted addition of color pigments. It is neither produced as a foam extrusion element nor does it have to be preceded by a laminating film web.

Namely, the adhesive layer is preferably an extruded hot adhesive medium, in particular an extruded polyolefin with here an added dye.

For such dyes, there is a wide selection and it is also possible to change the color of this adhesive medium relatively quickly to produce differently colored sealing deposits.

The resulting sealing inserts would be colored on one side for the viewer, for example, orange, on the other hand, white, because he sees there the unbacked and not provided with an adhesive layer surface of the carrier layer.

If so desired, the second adhesive layer could also be colored accordingly. It is also conceivable to provide the two adhesive layers on the different sides with different pigments in the components supplied for the adhesive layers and thus to offer a sealing insert that cause a differently colored impression from both sides.

It is also possible, of course, to provide sealing disks on both sides with a laminating film which is in each case connected to the carrier layer by means of an adhesive layer. Then the two sides of the sealing disc or sealing insert can be equipped with different colors by the two adhesive layers are colored differently. This may make sense, for example, to distinguish by inserting the different sealing inserts in container closures two types of a product to be accommodated in the container from each other or to provide each other for the end user a different visual impression. In addition to the possible with a laminating film and an adhesive layer differentiation of white (due to the carrier layer) and colored (due to the adhesive layer) can now occur two different shades.

However, there is also a practical reason why sealing discs on both sides are frequently and expediently provided with a laminating foil, although only on one side in the finished sealing insert by the user

Lamination is needed. However, the gaskets must be frequently in

Inserting machines container closures are supplied, in which they are to be inserted. In order to make this supply of the sealing inserts to the depositing machines as economically as possible, the sealing inserts are loosely packed packed in boxes. From these boxes they will be in

Feed hopper or filled in similar devices.

In order that the sealing inserts packaged in this way in the cartons can also be processed in the machines and the lamination after insertion into the closure in any case on the right, usually the contents adjacent side is present, the lamination of the carrier layer takes place on both sides. The sealing inserts are then so symmetrical, so that in a further processing, it does not matter which side of a sealing insert then, for example, is adjacent to a product to be packaged.

Otherwise, costly orientation of the sealing inserts at the manufacturer would have to be achieved by packaging them in hoses. The time-consuming loading of loading machines and magazines with only a few hundred sealing inserts containing hoses at the closure manufacturer can then be omitted.

The feeding machines can thus remove and use the sealing discs as desired in the processes in the state of the art, since the sealing insert can exert the same functions from both sides.

As long as the laminating films cause costs that are of the order of magnitude of the material for the carrier layers, or as long as the material costs are in any case higher than the costs of manufacturing and processing

Sealing deposits are largely negligible, it is easily possible, just to achieve symmetry simply both sides of a sealing insert

Laminating to provide, although a lamination on one side of the sealing insert for the practical application would be completely sufficient.

It should also be borne in mind that the feeding machines for the sealing inserts work very fast and the feeding speed is extremely high. It would therefore be unreasonable for the processing operation to provide time for the sorting and treatment of sealing liners when feeding into container closures. However, there are also applications in which the laminating films are quite expensive. This applies, for example, when very high-quality barrier films are to be used, which are desired as oxygen-impermeable layers in certain applications.

In such cases, a double-sided lamination of the carrier layers is no longer acceptable, since it also leads to a double area consumption of quite expensive laminating films.

Here can be created by an embodiment of the invention remedy. In this case, an embodiment is used in which the sealing insert has a different light / dark value and / or a different color from the side covered by the laminating film than on the side of the carrier layer not covered by the laminating film, namely by the in this Case only adhesive layer is colored in particular.

With this seemingly simple measure, the problem can be solved. While all previous attempts to sort such a sort have failed, for example by testing the slightly different sliding properties of the two sides of a sealing insert with or without laminating because the differences are too small, an intense optical color difference or difference in light / dark value at different shades of gray be detected reliably and easily without any problems. There are already optoelectronic devices that are used to orient partially metallic coated slices and to distinguish a metallically coated side from an uncoated side.

While it is understandable how to distinguish between the two sides of a disc in the case of metal-coated discs, this was by no means foreseeable in the case of the sealing inserts provided with transparent laminating films, since there was just no light / dark difference between the two sides.

However, a colored adhesive layer is now located between this carrier layer and the laminating film. Looking now at the non-laminated page the carrier layer, so you can see unchanged on the white foam. But if you look from the laminated side on the transparent laminating film and thus through it, so now is visually in front of the underlying white foam layer, a colored adhesive layer.

This adhesive layer can be given a very intense color, as desired, for example, a strong red or blue or even a gray, as different as possible from white color.

The sealing insert thus acts visually extremely different from both sides, although it has haptically and for the coming into contact with the sealing compound other substances has not changed, since all changes take place in the interior of the sealing insert.

It is preferred if the adhesive layer is extruded as a hot adhesive medium and introduced between the carrier layer and the lamination film. It is particularly preferred if the adhesive layer is formed by an extruded polyolefin with an added dye.

Tests have already shown that particularly appropriate corresponding dye can be supplied to this form of adhesive layer, the dye even very small amounts are required, since even a small addition of dye sufficient to detect detectable by the optoelectronic scanners difference of the two sides of the gasket achieve. Also, the adhesive effect can be adjusted very reliable and is affected by the addition of the dye in any way. Alternatively, it is also possible that this colored adhesive medium or this adhesive layer is an adhesive film. Namely, it becomes possible to run each one of the sheets of the base sheet material and the liner sheet material from each other from two feeding planes and to introduce the adhesive medium in the form of a polyolefin film sheet therebetween. This liquefies easily during or shortly after this process and thus bonds the two outer layers. Then the sealing inserts are punched out and packed loosely in boxes. Already at this time, any test tests can be made, as caused by the colored polyolefin film or the colored adhesive layer, the two sides of the sealing inserts a very different visual impression.

The practically any dyeability of this adhesive layer also makes it possible to take into account the wishes of the customer and / or properties of the contents to be packaged, ie to use a red adhesive medium, for example in the case of sealing inserts for a red liquid (red wine, red fruit juices). These respective sealing inserts are still visible to some extent depending on the form of use for the end user.

The manufacturer then packs the sealing disks from the carton into a so-called sorter or feeder or feed hopper (often referred to as hopper feeder in English), from which they are then fed to the loading machine.

It is very important for the user that apart from the different colors, nothing physically changes with the invention. The surface structures are the same on both sides as they would be in a conventional, uncolored liner so that all handling mechanisms, loaders, etc. need not be changed over and can handle the inked liners just like conventional ones from a previous batch.

This also means that the properties desired by the laminating film, such as its food-fastness or also approval properties, are not changed; as well as the properties that are desired by the carrier layer on the other side.

Thus, it is easy to realize conventional, non-colored sealing discs mixed or alternately with the inventive use, a color impression on the viewer causing sealing discs. The manufacturer of a product is therefore not dependent on a batch first consume conventional gaskets, then make adjustments, and then to be able to use only the new sealing washers. Instead, he can easily incorporate the new sealing washers into his production. It also does not retain residual quantities of previous products that can be completely used up.

All test and test measures, which are based for example on physical properties of the sealing discs, practically do not need to be changed. Neither does the thickness or the specific weight or the total weight of a sealing disc change, nor do the coefficients of friction and similar properties change. Only the optical properties are changed.

These altered optical properties make it possible, for example, two different types of sealing inserts, which are laminated, for example, with different films in order to be used for very specific purposes, distinguishable from each other. This has hitherto been a problem if such sealing disks look completely identical to the observer, but can only be used for one intended use. Here, a specific coloration desired by the customer can be provided from the outset by the manufacturer. Thereafter, these sealing inserts can be clearly distinguished from each other with the naked eye.

There are also possibilities to make the two sides of a sealing insert distinguishable by different colors on the two sides of the carrier layer. This applies, for example, if different, otherwise clear and transparent laminating films are used on both sides.

As mentioned above, a multilayer film web is first produced to produce the sealing inserts. This film web consists of the carrier layer and on one or both sides of the colored or undyed adhesive layers and finally the Kaschierungsfolien.

Also, this entire film web is an independently tradable product, because out of packaging or other economic reasons it occasionally desired to manufacture the sealing inserts on site only shortly before the packaging or the packaging of the finished products from the film webs. This happens in which the sealing inserts are mechanically punched out of these film webs and then can be used directly for further processing.

For the production of these sealing inserts, therefore, such film webs can also be produced at a different location and for a considerable time before punching out the sealing inserts, so that they are then delivered to the punching out production plants as finished web products, in particular in larger rolls. Such a film web thus solves the object of the invention, in which they can offer users sealing inserts for container closures, which cause a colored impression in the viewer.

In the following two embodiments of the invention will be described in more detail with reference to the drawing. Show it::

Figure 1 is a perspective view of a first embodiment of a sealing insert according to the invention, and

Figure 2 is a perspective view of a second embodiment of a sealing insert according to the invention.

A sealing insert consists in the first instance of a carrier layer 10. In preferred embodiments, this carrier layer 10 may be a foam layer, for example of polyethylene or of polypropylene. The support layer 10 is cylindrical as well as the entire sealing insert or sealing disc; So it has a circular circumference and is largely the same thickness at each point. Both are not necessarily a prerequisite, it can also be polygonal or differently shaped sealing discs, and certain tolerances in the thickness dimensions are possible.

The carrier layer 10 as shown in FIG. 1 is coated on one side with a first laminating film 20. This laminating film 20 consists of a transparent material, for example, a non-oxygen or poorly permeable film material. This film is compared to the carrier layer 10 is very thin and visually hardly noticeable. The representation in FIG. 1 is not true to scale.

The connection between the laminating film 20 and the carrier layer 10 is made by a first adhesive layer 30. This adhesive layer 30 is preferably supplied in hot form from an extruder; it may in particular be a polyolefin. Alternatively, the adhesive layer 30 can also be supplied in film web form during the production of the sealing insert. This adhesive layer 30 is colored differently from the prior art in the invention. It can be added, for example, with a bright Bordeaux red dye without losing their adhesive properties in any form. The dye as well as the remainder of the adhesive layer 30 penetrate neither through the carrier layer 10 nor through the laminating film 20, so are not noticeable from the outside, apart from the visual impression which they produce.

If, as in FIG. 1, a viewer looks at the sealing insert, he sees from above on a clear and transparent laminating film 20, that is to say because of the transparency through it. He thus looks to the colored adhesive layer 30. This colored adhesive layer 30 covers the white foam of the carrier layer 10, which is thus no longer visible to the viewer.

If he looks from below through a device 40 shown symbolically as a magnifying glass or with his eye on the sealing insert, he sees directly on the support layer 10, so sees the white foam.

If the illustrated magnifying glass 40 is replaced by an optoelectronic recognition device with a tool 40, the optoelectronic recognition device can automatically recognize on the basis of the perceived color or the light / dark value whether it has recognized a colored adhesive layer 30. From this, the opto-electronic detection device can then deduce that obviously also a laminating film 20 is present in this embodiment, so that it knows which side of the sealing insert faces it.

Accordingly, the optoelectronic detection device can now inform a control device as to whether and how to proceed with the sealing insert.

In a completely different embodiment, another possibility is provided in FIG. In the embodiment of FIG. 2, a second laminating film 22 is laminated on the side of the carrier layer 10 opposite the first laminating film 20 with the first adhesive layer 30. This second lining film 22 likewise consists of a transparent material, for example a film material which is not or hardly permeable to oxygen. This film is compared to the carrier layer 10 is very thin and visually hardly noticeable. It may be identical to the first laminating film 20.

The connection between the second laminating film 22 and the carrier layer 10 is made by a second adhesive layer 32. This second adhesive layer 32 is preferably supplied in hot form from an extruder; it may in particular be a polyolefin. Alternatively, the second adhesive layer 32 may be supplied in film web form in the production of the sealing insert.

This second adhesive layer 32 may be colored like the first adhesive layer 30. It can be mixed with the same dye, as well as with a different dye than the first adhesive layer 30. Again, the dye as well as the rest of the second adhesive layer 32 penetrates through the support layer 10 on one side still through the second laminating film 22nd on the other side. Apart from the visual impression on the viewer, therefore, there is no difference from the outside.

If, as shown schematically in FIG. 2 by a magnifying glass 40, a viewer looks at the sealing insert, then he sees the clear and transparent first laminating film 20 (from above) or the second laminating film 22 (from below), but through it on the first colored adhesive layer 30 and the second colored adhesive layer 32. The adhesive layers 30 and 32 each cover the white foam of the carrier layer 10, which is therefore no longer visible to the viewer. If the magnifying glass 40 is mentally replaced by an opto-electronic detection device with a tool 40, then it can also automatically decide on the basis of the perceived color, which color or whether it has ever seen a color. This can be an opto-electronic detection device then also see which side of the sealing insert was facing her. This may, for example, also have been a non-colored adhesive layer.

Accordingly, the optoelectronic detection device 40 can cause that for further processing, the sealing insert is either rotated or rejected or on the other hand further treated or transported in an unchanged position.

Insofar as the transparent laminating film 20 does not oppose this, it is also possible to use an ultraviolet or infrared-detectable color material for coloring the adhesive layer 30.

The tools 40 for the opto-electronic scanning need not be demanding for this application because they only have to distinguish two different states (light, dark) from each other, because other states can not occur. This can be easily achieved by proper selection of the dye, and accordingly, the opto-electronic tool 40 can also bring the decision making to the downstream devices very quickly.

LIST OF REFERENCE NUMBERS

backing

first laminating film second laminating film

Adhesive layer second adhesive layer

Luoe

Claims

claims

A sealing insert for container closures, comprising a carrier layer (10), with a transparent laminating film (20), and with an adhesive layer (30) connecting the laminating film (20) to the carrier layer (10), wherein the adhesive layer (30) has another bright - / Dark value and / or a different color than the carrier layer (10).

2. sealing insert according to claim 1, characterized in that the adhesive layer (30) is colored.

3. Sealing insert according to claim 1 or 2, characterized in that the carrier layer (10) on the first transparent laminating film (20) opposite side with a second transparent laminating film (22) is provided, and that the second laminating film (22) The second adhesive layer (32) connecting the carrier layer (10) is also colored.

4. sealing insert according to claim 2, characterized in that the first adhesive layer (30) and the second adhesive layer (32) are colored in different colors.

5. sealing insert according to one of the preceding claims, characterized in that the carrier layer (10) is a foam.

6. sealing insert according to claim 5, characterized in that the carrier layer (10) is a polyethylene foam.

7. sealing insert according to one of the preceding claims, characterized in that the carrier layer (10) consists of a white material.

8. Sealing insert according to one of the preceding claims, characterized in that the first adhesive layer (30) and optionally the second adhesive layer (32) is colored with a color that clearly contrasts with the color of the carrier layer (10).

9. Sealing insert according to one of the preceding claims, characterized in that the adhesive layers (30, 32) are extruded as a hot adhesive medium and introduced between the carrier layer (10) and the laminating film (20).

10. Sealing insert according to claim 9, characterized in that the adhesive layers (30, 32) are formed by an extruded polyolefin with an added dye.

1 1. A sealing insert according to one of the preceding claims 1 to 8, characterized in that the colored adhesive layers (30, 32) are each an adhesive film.

12. Multilayer film web for the production of sealing inserts according to one of the preceding claims.