Coffee capsule having laser engraving as predetermined breaking point

Abstract

The invention relates to a coffee capsule (K) for storing ground coffee in order to prepare a coffee beverage using the ground coffee, comprising a film (1) which at least partially delimits the interior (6) of the coffee capsule (K), the film (1) being in the form of a monofilm or composite film having at least one layer (2, 3), and comprising a predetermined breaking point in order to tear at the predetermined breaking point by means of mechanical pressure and to allow access to the interior (6), wherein at least the layer (2) which is outermost in relation to the interior (6) is made of plastics material. For the purpose of cost saving, the predetermined breaking point is in the form of a laser engraving (4) in which the film thickness is reduced locally by means of material removal by a laser.

Description

[0001] Coffee capsule with laser engraving as a predetermined breaking point

[0002] The invention relates to a coffee capsule for storing coffee powder for preparing a coffee beverage according to the preamble of claim 1, as well as a manufacturing method for such a coffee capsule according to the preamble of claim 10. Furthermore, a preparation method for coffee beverages is proposed.

[0003] Coffee capsules for preparing hot coffee drinks are well known in the art. While some capsules are traditionally made of aluminum, more environmentally friendly products now attempt to use recycled material, such as plastic, as described in EP 4 173 978 A1, and / or a compostable material, as proposed in EP 3 847 014 A1, for example. This is because the capsule is typically a disposable item and is thrown away after one use. However, it has been found that manufacturing using such an alternative to aluminum is generally more cost-intensive.

[0004] The object of the invention is to propose a coffee capsule or a manufacturing process for a corresponding coffee capsule which can eliminate these disadvantages and in particular allows more cost-effective production without loss of quality.

[0005] The object is achieved, starting from a coffee capsule or a manufacturing method of the type mentioned above, by the characterizing features of claim 1. Advantageous embodiments and developments of the invention are possible through the measures mentioned in the dependent claims.

[0006] The coffee capsule according to the invention stores coffee powder or a powder for preparing a beverage. The coffee capsule has an interior for this purpose. Preparation itself is generally carried out by rinsing the interior so that hot water comes into contact with the powder. To gain access to the interior, the capsule must be opened or broken open. For this purpose, a film is provided which at least partially delimits the interior of the capsule. This film can generally be used as the lid of the capsule. A film can be broken through more easily than, for example, a thicker plastic tub, such as is the case with blister packs.

[0007] Originally, aluminum foil, which is commonly used for packaging and storing food, was used primarily. However, aluminum production is not particularly environmentally friendly.

[0008] The film can be broken open mechanically using a mandrel that drills into the film. However, particularly with plastic films or plastic capsules, there is a risk that film particles or film residues will become detached and get into the drink, which should be avoided for various reasons (health, quality, hygiene). However, plastic films usually have poorer breaking properties than aluminum foil. If an additional barrier layer is added to a plastic film, breaking properties comparable to those of aluminum foil are often not available, so that the suitability for capsule production is questionable. In the case of plastic films, e.g. monofilm or recycled films, mechanical breaking can also be achieved by high pressure from the steam acting on the capsule. But here too there is a risk that film particles or film residues will become detached.

[0009] As an alternative, one way to improve the breaking properties of a plastic film is to use an embossing roller to create very fine notches. However, during the development of the invention, it was recognized that this method is expensive because it is complex and entails high tool costs. Not only does the embossing roller have to be manufactured, but it also wears out quickly as a tool. Furthermore, temperature influences lead to expansion problems. Manufacturing methods are inflexible, and adjustments may require the embossing tool to be remade each time. Requirements for long-term quality cannot be met.

[0010] The invention is therefore characterized by the creation of a predetermined breaking point that breaks under mechanical pressure at a defined location on the film. This predetermined breaking point is created as a laser engraving, making a mechanical embossing tool, for example, obsolete. Mechanical tool wear is thus essentially completely avoided.

[0011] A laser engraving according to the invention also offers further advantages:

[0012] - There's no need to manufacture a new tool, which is both complex and expensive, if the capsule product to be manufactured changes, for example, if the shape / contour of the predetermined breaking point or the depth or track width of the predetermined breaking point is altered. Instead, it's usually sufficient to reprogram the laser control system.

[0013] - Even if the capsule material is changed, e.g. a different plastic, no other tool is usually necessary, just a change in the control process.

[0014] - The changeover time is also much shorter because, for example, only the control system needs to be reprogrammed, which is usually much faster than manufacturing a stamping tool. This allows for higher production numbers.

[0015] To enable the film to be broken open cleanly and with a defined geometry, the laser engraving can be linear. In principle, it is also conceivable to provide weakenings in the material using point-shaped recesses. Especially when the capsule is opened by mechanical pressure, in particular by steam, in the area of ​​the predetermined breaking point - for example when the interior of the capsule is rinsed with hot water to prepare a drink - no film residue or film particles should get into the water and therefore later into the drink. It is therefore advantageous to provide a predetermined breaking point that runs over a longer distance, because otherwise the film material would have to tear open even at points that do not have any weakening in terms of their thickness, which in turn could make it easier for individual film components to tear out.The more precisely the predetermined breaking point is prepared by laser engraving, the more reproducible and qualitatively better the beverage preparation can be. To completely detach a surface, a closed area of ​​the foil can also be delimited by the laser engraving. However, with capsules, the printing should generally not result in a continuous area being severed from the foil, since the capsule, as a packaging container, should be opened but not divided into several parts, which could, for example, impede the water flow.

[0016] In a further development of the invention, the laser engraving takes place as a so-called cold ablation process. Cold ablation, for example, enables engraving without a melted edge, thus preserving the smooth film surface. A thickening at the edge can, for example, lead to the undesirable deposition of tiny dirt particles. It can also cause sealing problems or similar issues and is therefore a rather disruptive artifact. Such cold ablation can be achieved, for example, using a laser emitting in the ultraviolet range, at a wavelength of approximately 355 nm. In contrast, a CO2 laser results in material ablation with a melted edge.

[0017] The coffee capsule can be designed without aluminum in an environmentally friendly way. A recyclable material can be used instead. Compostable materials are also conceivable. Plastic, for example, can generally be easily recycled. Some plastics can even be composted. In order to open a film at the predetermined breaking point using the steam pressure generated in the coffee machine or vending machine, it can be advantageous to make the film as thin as possible, for example in the form of a single-layer monofilm. However, the use of composite materials is also conceivable, which enable more defined properties as a composition of different material functionalities. One layer, in particular the outer layer on the surface, can be designed as a plastic layer, which is also provided with the laser engraving. It is also conceivable that at least two or all layers are made of plastic.

[0018] One of the layers can, for example, be designed as a barrier layer to protect the food product stored in the interior, for example as an EVOH layer (EVOH: a copolymer of ethylene and vinyl alcohol, produced from the polymerization of ethylene and vinyl acetate). The barrier layer can also be laser engraved to create a predetermined breaking point. Until now, the required breaking properties of a predetermined breaking point could hardly be achieved with the use of barrier layers using the state of the art if only embossing tools were used to weaken the material.

[0019] Depending on the embodiment of the invention, the track depth can, for example, cover one layer and not penetrate it completely, or it can cover several layers. As a rule, this laser engraving looks like a wedge or a blind hole in a section through the film transverse to its course, which ends in one of the film layers. The film layer or layers above it, unless it is a monofilm, are then completely penetrated. In the case of composite materials, it may be that the laser engraving has to cover more than one layer in order to enable the film to be opened.

[0020] Due to its high tensile strength, biaxially oriented PET film (BOPET, where PET stands for polyethylene terephthalate) is also ideal for aroma-tight food packaging. The film thickness can generally be between 15 μm and 50 μm, for example. To achieve a good compromise between strength and openness of the predetermined breaking point, the removal depth can be between 5 μm and 30 μm, while the track width varies between approximately 15 μm and 50 μm, depending on the design.

[0021] An advantageous embodiment of the invention is the capsule in the form of a blister pack. This comprises a plastic molded or deep-drawn part, which defines the interior due to its shape. It has an opening to which a film can be applied and secured or sealed. The film is generally thinner and weaker than the deep-drawn part, so that the predetermined breaking point can also be integrated into the film. The blister pack can be transported relatively safely.

[0022] Accordingly, an inventive

[0023] Manufacturing process by creating a predetermined breaking point in the form of a laser engraving by removing a part of the film using a laser, whereby the removal takes place as a local reduction of the film thickness, so that the predetermined breaking point is designed as a laser engraving. In this case, the advantages already explained in connection with the coffee capsule can be used. More environmentally friendly aluminum-free capsules can be produced without mechanical tools and instead with an optical tool, a laser for creating a

[0024] Laser engraving can be used. This allows for cost savings and shortened production times. Material can also be saved because new tools do not have to be built due to product changes or wear. Temperature influences and the like play a lesser role.

[0025] The films and packaging produced have lower waste. In a further development of the invention, the geometry of the laser engraving is achieved using a mirror deflection system or a scanner. By programming the appropriate control system, which aligns the mirrors, the laser beam can be directed, thus creating a wide variety of geometries.

[0026] Alternatively , it is also conceivable to leave the laser stationary and instead to move the film relative to the laser beam using a positioning system in order to achieve the desired geometry .

[0027] Net-like line structures can be created in the same way as parallel lines. The line spacing can also be varied. In areas where lines would otherwise intersect, a point without overlaps can be created by interrupting the laser beam that would otherwise impinge there. The laser can also be temporarily switched off in these areas. These measures can be used to adjust the pressure or force required to tear the film at the predetermined breaking point.

[0028] According to the invention, a coffee capsule is also proposed which has undergone the removal of an engraving line or track without a melted edge, so that the engraving can be located in an outer plastic layer.

[0029] In some packaging containers, particularly in tablet packaging in the form of a push-through pack, the film can be arranged so that the laser engraving is on the inside, from where the force acts on the film. Such an arrangement is also conceivable in principle for coffee capsules. In addition, a preparation method for coffee beverages is proposed in which a coffee capsule is provided, steam is generated and the steam is directed onto the film of the capsule in order to open the predetermined breaking point using pressure. This can reduce the risk of film particles or film residues getting into the beverage during preparation.

[0030] Examples of implementation:

[0031] Embodiments of the invention are illustrated in the drawings and are explained in more detail below, giving further details and advantages.

[0032] In detail:

[0033] Fig . 1 : a schematic section through a foil , the

[0034] Invention,

[0035] Fig. 2: a schematic section through a coffee capsule according to the invention,

[0036] Fig. 3 : a schematic representation of a laser engraving device according to the invention, as well as

[0037] Fig . 4 : a schematic representation of a

[0038] Manufacturing process of a coffee capsule, the invention.

[0039] Figure 1 shows a schematic section through a film 1, which is composed of two layers 2, 3. Both layers 2, 3 are made of plastic. A laser engraving 4 is incorporated into the film 1, which in turn has a track width B and a depth T. The laser engraving 4 forms the predetermined breaking point in the film 1 and penetrates completely through the outer layer 2 (here in Fig. 1: the upper layer 2). However, the laser engraving 4 also partially covers the lower layer 3. The film 1 is therefore locally reduced in thickness in the area of ​​the laser engraving 4. As can be seen to the side of the laser engraving 4, there are no melt edges on either side of the laser engraving 4. The predetermined breaking point or laser engraving 4 is wedge-shaped in this case. Compared to a wider, trough-like shape, this offers the advantage that the point can break more easily when pressure is applied.

[0040] Figure 2 shows a schematic section through a coffee capsule K in the form of a blister pack. It consists of a pot-shaped deep-drawn part 5 made of a thicker plastic than the film 1 used as a lidding film, with which the deep-drawn part 5 is covered. Inside the deep-drawn part 5, bordered at the top by the covering film 1, is the interior 6 of the coffee capsule K, which is filled with coffee powder. The film 1 is sealed on the edge of the deep-drawn part 5.

[0041] A predetermined breaking point with a laser engraving 4 can be seen in Figure 3 on a foil 1. It is round, with the track 4 interrupted at one point so that the material does not get into the coffee during the brewing process, ie the lid in the middle of the predetermined breaking point remains connected to the foil 1.

[0042] Figure 4 outlines a manufacturing process:

[0043] - The foil can be provided.

[0044] - The laser is positioned relative to the film using a scanner.

[0045] - Then the laser engraving takes place, with the laser still tracing the desired engraving line using the scanner. - The film can be cleaned or sterilized if necessary, e.g., by gently blowing it off with a gas.

[0046] Meanwhile, a kind of blister can be created. This is done by following these steps:

[0047] - A molded part is deep drawn.

[0048] - The deep-drawn part is cleaned, e.g. by blowing.

[0049] - The molded part is filled with coffee powder. If necessary, this is done under gassing to ensure the coffee powder stays in the capsule K longer and doesn't lose its aroma.

[0050] Both the deep-drawn part 5 and the film 1 form the finished capsule K. Film 1 and the deep-drawn part 5 must be connected and sealed to prevent ambient air from reaching the coffee powder stored in the interior 6 and damaging it or its aroma. During filling, the capsule is weighed or pre-portioned amounts of powder are added.

[0051] All embodiments and developments of the invention have in common that a predetermined breaking point is created to tear through mechanical pressure at the predetermined breaking point and provide access to the interior, with at least the outer or inner layer with respect to the interior being made of plastic. They are characterized in that the predetermined breaking point is designed as a laser engraving, in which the film thickness is locally reduced by laser ablation. List of reference symbols:

[0052] 1 slide

[0053] 2 outer plastic layer 3 further layer

[0054] 4 Laser engraving

[0055] 5 Deep-drawn part

[0056] 6 Interior of the capsule

[0057] 7 Interruption of engraving B Track width

[0058] K coffee capsule

[0059] T track depth

Claims

Claims:

1. Coffee capsule (K) for storing coffee powder or a preparation powder for preparing a beverage, in particular a coffee beverage or other hot beverage, with the powder, with a film (1) which at least partially delimits the interior (6) of the coffee capsule (K), wherein the film (1) is designed as a monofilm or composite film with at least one layer (2, 3) and has a predetermined breaking point in order to tear by mechanical pressure at the predetermined breaking point and to release access to the interior (6), wherein at least the outer and / or inner layer (2) with respect to the interior (6) is made of plastic, characterized in that the predetermined breaking point is designed as a laser engraving (4), in which the film thickness is reduced locally by ablation with a laser.

2. Coffee capsule (K) according to claim 1, characterized in that the laser engraving (4) is at least partially, in particular completely, linear and / or delimits a closed surface area on the film (1).

3. Coffee capsule (K) according to one of the preceding claims, characterized in that the laser engraving (4) is limited without a melting edge and thus without local thickening of the film (1) at the edge of the track of the laser engraving (4).

4. Coffee capsule (K) according to one of the preceding claims, characterized in that the film (1) and / or all layers (2, 3): • made of plastic and / or • made of a recyclable material and / or • is / are made of aluminum-free material.

5. Coffee capsule (K) according to one of the preceding claims, characterized in that the film (1) has at least one barrier layer (2, 3), in particular an EVOH layer.

6. Coffee capsule (K) according to one of the preceding claims, characterized in that the removal of the laser engraving (4) affects at least one, in particular all layers (2, 3) of the film (1).

7. Coffee capsule (K) according to one of the preceding claims, characterized in that the film (1): • has a thickness of 15 pm to 50 pm and / or • is designed as a 2-layer BOPET film.

8. Coffee capsule (K) according to one of the preceding claims, characterized in that the laser engraving (4) has a depth (T) of 5 pm to 30 pm and / or a track width (B) of 15 pm to 50 pm as a result of the ablation.

9. Coffee capsule (K) according to one of the preceding claims, characterized in that the coffee capsule (K) is designed as a blister, which comprises a plastic molded part (5) which forms the interior (6), and a film (1) as a rear wall, which at least partially covers the plastic molded part (5) and is connected to it, in particular sealed, in order to at least partially delimit the interior (6).

10. A method for producing a coffee capsule (K) for storing coffee powder for preparing a coffee beverage with the coffee powder, comprising a film (1) which at least partially defines the interior (6) of the coffee capsule (K), wherein the film (1) is designed to tear at a predetermined breaking point by mechanical pressure and to release access to the interior (6), comprising: • Providing the film (1) as a monofilm or composite film with at least one layer (2, 3), in which at least the outer and / or inner layer (2) with respect to the interior (6) is made of plastic, • Creating a predetermined breaking point in the form of a laser engraving (4) by removing a part of the film (1) by means of a laser, wherein the removal takes place as a local reduction of the film thickness, by a laser, so that the Predetermined breaking point is designed as a laser engraving.

11. Manufacturing method according to one of the preceding claims, characterized in that a UV laser, preferably in the range of a wavelength of 355 nm, is used as the laser, in particular to carry out cold removal without the formation of a melt edge in the edge region of the laser engraving (4).

12. Manufacturing method according to one of the preceding claims Claims, characterized in that the laser beam of the laser used for ablation and / or production of the laser engraving (4): • is positioned relative to the film via a mirror deflection system, preferably a scanner and / or • remains stationary while the film (1) is moved relative to the laser beam.

13. Manufacturing method according to one of the preceding claims, characterized in that the following material is provided as film (1): • a film with a thickness of 15 pm to 50 pm and / or • a 2-layer BOPET film .

14. Manufacturing process according to one of the above Claims, characterized in that during the removal a laser engraving (4) of the track width (B) of 15 pm to 50 pm is generated and / or the ablation produces a depth of laser engraving of 5 gm to 30 gm.

15. Manufacturing method according to one of the preceding claims, characterized in that the The breaking behaviour of the predetermined breaking point is adjusted by • a network-like line structure is removed as a laser engraving and / or • at least two parallel lines are removed as a laser engraving and / or the line spacing of the laser engravings is varied during removal.

16. Manufacturing method according to one of the aforementioned Claims, characterized in that in addition to the lines (4) at least one point-shaped structure is removed.

17. Manufacturing method according to one of the aforementioned Claims, characterized in that intersecting lines without overlapping are produced as laser engraving (4) by interrupting the laser beam in the overlapping area of the lines and / or switching off the laser there.

18. Coffee capsule (K) obtainable according to one of the preceding claims.

19. Method for preparing a coffee beverage, comprising: • Provision of a coffee capsule (K) according to one of the preceding claims, • Generating a water vapor, • Directing the water vapor onto the film (1), • The coffee capsule (K) breaks open due to the pressure of the steam at the predetermined breaking point.

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