EP3853021A1

EP3853021A1 - Film for applying onto a target object

Info

Publication number: EP3853021A1
Application number: EP19773400.7A
Authority: EP
Inventors: Christian Hübner
Original assignee: Profol GmbH
Current assignee: Profol GmbH
Priority date: 2018-09-19
Filing date: 2019-09-19
Publication date: 2021-07-28
Also published as: WO2020058398A1; DE102018215927B4; US20210348034A1; DE102018215927A1

Abstract

The invention relates to a film for applying onto a target object, comprising at least one cover layer and an adhesive layer. The cover layer consists of a first polyolefin-based plastic with a first layer thickness, and the adhesive layer consists of a second polyolefin-based plastic with a second layer thickness which is smaller than the first layer thickness, wherein the adhesive layer has an inorganic filler with a weight proportion of more than 20%.

Description

Foil for application to a target object

Technical field

The present invention relates to a film for application to a target object. The film can be applied to the target object using a tool under the action of heat and / or pressure. In a preferred embodiment, the film is used to close packaging - for example a yoghurt cup - for food.

Technical background

In the field of food packaging, for example, the task often arises of closing a target object in the form of a container (for example a mug, bucket, bin, etc.). It is known to provide such vessels as a target with an edge along the opening and to apply a lid made of a film to this edge for closure. The lid can consist of different materials and can also be applied using a wide variety of methods. Adhesive bonding, pressing or welding are among the methods that can be used. The selected materials and processes can then each provide certain advantages, but often also suffer from corresponding disadvantages, so that the selection of materials and processes for a specific use and application is often limited. In recent times, additional tasks have arisen, particularly in the packaging of consumer goods (food, medication, cosmetics, consumables, etc.): For example, a certain type of purity of the packaging as a whole is often necessary for sufficient recyclability. It is often required that both the container (ie the target object in the form of a cup, for example) and the closure (lid) are made of a sufficiently similar or even the same material so that they can be easily recycled when disposed of. Nonetheless, further factors have to be considered, particularly in the area of consumer goods. At this point, good printability of the materials, compliance with hygiene regulations and a satisfactory opening experience by the user are mentioned. The latter is particularly important in the case of foodstuffs, since the user, ie the consumer, is to be given a secure feeling that, firstly, the container was reliably closed before opening, and secondly that after opening the container has no damage and that the container is not damaged The closure has been opened satisfactorily. This can be a complete detachment of the lid and / or good resealability.

With regard to compliance with hygiene standards and regulations, it should be mentioned that filling and closing a food packaging does not contaminate the exterior of the packaging with content (ie the food) or the tools and equipment for packaging with the content or goods to be filled should. For example, residues outside not only leave a dirty impression on the packaging, but can also spoil and / or contaminate other goods. Contamination of the filling system (including tools (s), brackets, transport mechanisms, etc.) itself is often undesirable, especially if the goods to be filled are perishable foods.

There is therefore a need for a technology which achieves the above-mentioned objectives when applying a film, in particular in Connection of packaging of a good to be filled. Economy, reliability and overall satisfactory compliance with all applicable standards should also be taken into account. It is therefore a particular object of the present invention to provide a film with which one or more of the aforementioned objectives can be achieved.

Summary

The problems and tasks mentioned are solved by the subject matter of the independent claims. Further advantageous refinements of the present invention are specified in the dependent patent claims.

According to one embodiment of the present invention, a film is provided for application to a target object and comprising at least one cover layer and an adhesive layer, the cover layer consisting of a first polyolefin-based plastic with a first layer thickness, the adhesive layer consisting of a second polyolefin-based plastic with a second layer thickness exists, which is smaller than the first layer thickness, and wherein the adhesive layer has an inorganic filler with a weight fraction of greater than 20%.

Brief description of the figures

The embodiments of the present invention are explained and clarified in particular in the context of the following figures. The scope of protection is not intended to be limited to this embodiment, and the figures and the associated description are therefore only intended to illustrate the general idea of the invention. In the attached figures shows Figures 1A to ID are schematic sectional views of

Films according to corresponding embodiments of the present invention; FIGS. 2A to 2C are schematic views in connection with the use and advantages of foils according to corresponding embodiments of the present invention; 3 shows a schematic sectional view of a

Tool for applying a film according to an embodiment of the present invention, and Figure 4 schematically shows the use of a

Tool when applying a film according to an embodiment of the present invention to a target object.

Detailed description

FIGS. 1A to ID show schematic sectional views of foils according to corresponding embodiments of the present invention. FIG. 1A shows a film 100 for application to a target object. The film 100 comprises at least one cover layer 101 and an adhesive layer 102, the cover layer 101 consisting of a first polyolefin-based plastic with a first layer thickness, the adhesive layer 102 consisting of a second polyolefin-based plastic with a second layer thickness which is smaller than the first layer thickness , and wherein the adhesive layer 102 has an inorganic filler with a weight fraction of greater than 20%. In a further corresponding embodiment, the Adhesive layer 102 has particles that can be excited by high-energy radiation. These excitable particles can preferably be contained in a concentration in a range from 100 ppm to 300 ppm.

FIG. 1B shows a film 100 'for application to a target object. The film 100 ′ comprises at least an upper cover layer 102, a core layer 112 and an adhesive layer 102, the cover layer 102 and / or the core layer 112 consisting of a first polyolefin-based plastic and the upper cover layer 102 together with the core layer 112 forming a first layer thickness, wherein the adhesive layer 102 consists of a second polyolefin-based plastic with a second layer thickness that is smaller than the first layer thickness, and wherein the adhesive layer 102 has an inorganic filler with a weight fraction of greater than 20%. In a further corresponding embodiment, the core layer 112 has particles that can be excited by high-energy radiation. These stimulable particles can preferably be contained in a concentration in a range from 50 ppm to 200 ppm.

FIG. IC shows a film 100 "for application to a target object. The film 100" comprises at least one cover layer 101, an adhesive layer 102, and on the latter a further adhesive layer 103. The cover layer 101 can consist of a polyolefin-based plastic with a first layer thickness and adhesive layers 102, 103 can consist of a second polyolefin-based plastic with a respective layer thickness, which individually or together can be smaller than the first layer thickness. The adhesive layer 102 can have an inorganic filler with a weight fraction of greater than 20%. The further adhesive layer 103 can have a layer thickness in a range from lym to 4ym and, compared to the adhesive layer 102, cannot contain any filler, but can consist of the same base polymer as the adhesive layer 102. FIG. ID shows a film 100 ″ ″ for application to a target object. The film 100 ″ ″ can be regarded as a combination of the film 100 ′ described in connection with FIG. 1B and the film 100 ″ described in connection with FIG. IC. The film 100 ″ ″ thus comprises at least one cover layer 102, a core layer 112 , an adhesive layer 102, and an additional adhesive layer 103 on the latter. With regard to all other properties such as layer thickness, materials and fillers, the preferred configurations according to the descriptions in connection with FIGS. 1A to IC apply in each case , Core layer, the “first” adhesive layer as a separable or peelable separating / peeling layer, and the “second” further adhesive layer as a non-separable or peelable sealing layer.

In general, the cover layer (s) can have a layer thickness in a range from 70 μm to 105 μm and the adhesive layer a layer thickness in a range from 7 μm to 20 μm (preferably approximately 8 μm). If a multilayer cover layer, such as that shown in FIG. 1B, is provided, the upper cover layer can have a layer thickness in a range from 10 μm to 20 μm and the core layer a layer thickness in a range from 60 μm to 85 μm.

In general, the polyolefin-based plastics can each have polyethylene (PE) and / or polypropylene (PP) and the adhesive layer one or more acrylates. The inorganic filler can have particles of chalk, lime, talc, and / or platelet-shaped particles, the diameter of the particles being in a range from 1 μm to 2 μm. The proportion by weight of the inorganic filler may range from 20% to 30%, and more preferably ranges from 25% to 50%.

FIGS. 2A to 2C show schematic views in connection with the use and advantages of foils according to corresponding embodiments of the present invention. In FIG. 2A shows a shaped piece 3 of a film according to an embodiment of the present invention from above. The shaped piece can serve as a closure lid of a container, for example as part of a food packaging, and can therefore have a tab 30 which makes it easier to remove the lid.

As shown in FIG. 2B, the shaped piece can form a lid 3 for a cup 4, the film of the lid 3 being applied to an edge 40 of the cup 4 - as an exemplary target object. This application can include welding with a tool. The properties of the film according to the embodiments of the present invention allow the cover to be applied to the target object in such a way that no contamination occurs in and around a closure area. Furthermore, as shown in FIG. 2C, the film can be removed from the target object in a simple manner without tools and without residues (“peelable”). These advantages can be achieved in particular by the preferred selection of the filler or the fillers in the adhesive layer 102 and its In particular, a residue-free lifting achieves a satisfactory opening experience, ie the user experiences the feeling of a reliable closure and a corresponding opening. contains or contained the goods to be packaged or food) and leaks, and also enables satisfactory and reliable reclosing.

FIG. 3 shows a schematic sectional view of a corresponding tool for applying a film according to an embodiment of the present invention. A tool 1 is used to apply a film to a target object under the action of heat and / or pressure. The tool 1 comprises a carrier 11 made of a first material and a web 21 made of a second, elastic material, the web 21 on the Carrier 11 is arranged, and has at least one area W, which is curved outwards. Here, a circular or elliptical basic shape can emerge, which can be described by one or more radii.

The first material of the carrier 11 is preferably a metal, such as, for example, aluminum, copper, an aluminum alloy, a copper alloy, brass, bronze, amcorloy, or steel. In embodiments in which the tool is used to apply a film to a target object under the action of heat, the first material should have a sufficient or the desired thermal conductivity or heat capacity. Is welding, i.e. if at least partial melting of the film and possibly parts of the target object is desired, sufficient heat conduction is required to conduct the necessary heat of fusion within the desired time from a heater or heat source (not shown) to the curved area of the web.

The second material of the web is preferably a high-temperature-resistant silicone or other elastomer with a Shore A hardness between 50 and 80. The second material can moreover have a composite material which has one or more fillers in a carrier material (aforementioned silicone / elastomer) serve in particular to increase the thermal conductivity and / or the specific heat capacity while maintaining the mechanical strength. In such configurations, the heat input and pressure transfer to the film and / or the material of the target object can be adapted in the area of a closure.

The carrier made of the first material can not only serve for mechanical stability, but also carries the required heat to the area of the web which is curved outwards. This area can therefore be pressed onto a film and an area (eg edge of a cup, for details see below in connection with FIG. 4) of the target object, the necessary heat being applied to the closure area is introduced. The curvature towards the outside (bombage) preferably initially enables a linear contact. When the tool is further fed onto the film, the outwardly curved region of the web is pressed onto the film, the mechanical contact area starting from the initial line increasing increasingly in both directions away from the line. In this way, an off or. Pressing away any contamination on the film or on the sealing edge of the target object. In the area of critical packaging (hygienically critical packaging such as in the field of food packaging), it can thus be ensured that contamination or residues of the goods to be filled adversely affect the adhesion or the bond between the film and the target object. The web 21 can generally be designed as a ring or a circle.

The tool 11 can furthermore have an inner carrier 31 made of a third material. This third material can be the same as the aforementioned first material or one of the following or any combination of several of the following materials: machinable ceramic, ceramic, glass fiber reinforced

Ceramics, glass fiber reinforced plastic (GRP), high temperature-resistant and / or foamed plastics, foamed silicates (aerogels), expanded glass, and any other thermally and mechanically resilient insulating material. Furthermore, the third material and / or the inner carrier can be at least partially provided with a coating in order to achieve food conformity. More preferably, the third material has a continuous use temperature of at least 250 ° C.

FIG. 4 schematically shows the use of a tool when applying a film according to an embodiment of the present invention to a target object. As shown, a tool 11 is intended to apply a film 3 to a target object, e.g. B. a cup 4, apply under the action of heat and pressure. For this purpose, the target object (for example a container for a food such as a yoghurt cup) is placed in a holder 5. An edge 40 of the cup 4 lies on this holder 5 and the film 3 can thus be pressed onto the edge 40 using the tool 11. For this purpose, the web 21 of the tool 11 is brought or kept to a target temperature and below a well-defined or controlled one

Pressure on the edge 40 driven. The film 3 in

Area of the edge 30 applied to the target object by pressing, welding and / or otherwise connecting the materials of the film 3 and the edge 40. In particular, the adhesive layer 102 of the film 100, 100 ', 3 comes into contact with the material of the target object

(Here, for example, the edge 40 of the cup 4) and the film can be peeled, reclosable and reliably connected to the target object.

Although detailed embodiments of the invention have now been described, they should only be used for a better understanding of the invention and its effects. The scope of protection is defined by the following claims and is not intended to be limited by the detailed description.

Claims

Expectations :

1. A film for application to a target object and comprising at least one cover layer and an adhesive layer, the cover layer consisting of a first polyolefin-based plastic with a first layer thickness, the adhesive layer consisting of a second polyolefin-based plastic with a second layer thickness that is smaller than that first layer thickness, and wherein the adhesive layer has an inorganic filler with a weight fraction of greater than 20%.

2. The film according to claim 1, wherein the cover layer has a layer thickness in a range from 70 μm to 105 μm.

3. A film according to claim 1 or 2, wherein the adhesive layer has a layer thickness in a range from 7 μm to 20 μm.

4. Film according to one of claims 1 to 3, wherein the

Cover layer is an upper cover layer and the film has at least one core layer.

5. Film according to one of claims 1 to 4, wherein the film has a further adhesive layer on the adhesive layer.

6. Film according to claim 5, wherein the further adhesive layer has a layer thickness in a range from lym to 4ym.

7. Film according to claim 5 or 6, wherein the further adhesive layer has no filler and / or consists of the same second polyolefin-based plastic.

8. Film according to one of claims 4 to 7, wherein the upper

Cover layer has a layer thickness in a range from 10 μm to 20 μm, and the core layer has a layer thickness in a range from 60 μm to 85 μm.

9. The film of claim 8, wherein the core layer contains particles that can be excited by high-energy radiation.

10. Film according to one of claims 1 to 9, wherein the polyolefin-based plastic comprises polyethylene, PE, and / or polypropylene, PP.

11. Film according to one of claims 1 to 10, wherein the

Adhesive layer has one or more acrylates.

12. Film according to one of claims 1 to 11, wherein the inorganic filler has particles of chalk, lime, talc, and / or platelet-shaped particles.

13. Film according to one of claims 1 to 12, wherein the

Adhesive layer contains particles that can be excited by high-energy radiation.

14. Film according to one of claims 1 to 13, wherein the

The diameter of the particles is in a range from 1 μm to 2 μm.

15. Film according to one of claims 1 to 14, wherein the

The proportion by weight of the inorganic filler is in a range from 20% to 30%, and more preferably in a range from 25% to 50%.