Portion capsule

Abstract

A portion packing element (1a; 1b) for forming a wall of a portion packing (1) for receiving an extraction material has at least one first layer made of a first plastic material, wherein the portion packing element is substantially free of aluminum particles to achieve improved sortability. The portion packing element (1a; 1b) may also be substantially free of carbon black particles.

Description

[0001] The invention relates to the preparation of beverages or the like from an extraction product, such as ground coffee, contained in a portion pack, for example a portion capsule. It relates to a portion pack for containing the extraction product and its parts, which can in particular be a portion pack cup and a portion pack lid.

[0002] Extraction devices for preparing beverages from a product contained in a portion-sized container are known, for example, as coffee, espresso, or tea machines. In many such systems, the portion-sized containers are designed as capsules (portion capsules) in which the product is sealed, for example, hermetically. For extraction, the capsule is pierced on two opposite sides. A brewing liquid—generally hot water—is introduced into the first side. The brewed product is discharged from the capsule on the second side.

[0003] Among single-serve capsules, capsules are known whose capsule walls consist essentially of plastic. There is a need to recycle such capsules as completely as possible. DE 10 2014109 555 describes single-serve coffee capsules with a capsule wall made of a plastic material that is free of soot particles, with the capsule wall comprising a white layer. Soot particles are often used to darken capsules, but they lead to the corresponding capsules not being correctly classified in waste sorting facilities. DE 10 2014109 555 teaches that such incorrect classification can be prevented by omitting soot particles and instead providing a white layer in the capsule wall.

[0004] However, it appears that the sortability of the capsules in waste sorting plants still appears to be in need of improvement, even when the capsule wall is truly free of soot particles and the capsule also has a white layer, especially on the inside. Rather, reliable detection in such waste sorting plants also appears to depend on other factors.

[0005] It is an object of the present invention to provide a capsule wall and a capsule with such a capsule wall, which overcomes disadvantages of the prior art and which in particular ensures, enables or facilitates improved reliability in the waste sorting process.

[0006] This problem is solved by the invention as defined in the patent claims.

[0007] According to one aspect of the invention, a portion pack element is provided which serves to form a portion pack wall—that is, a portion pack cup or a portion pack lid. The portion pack element has at least a first layer made of a first plastic material and is characterized by being substantially free of aluminum particles.

[0008] «Substantially free from aluminium particles» means that the proportion (percent by weight) of Aluminium is not more than 0.08%, ie the proportion of aluminium is between 0 and 0.08%. In particular, the proportion (weight percentage) of Aluminiumpigmenten not more than 0.08%, in particular where the mass fraction of aluminum not present in aluminum pigments does not exceed 0.01%. Dyes used to color portion capsules often contain aluminum pigments, which complicate classification in waste sorting facilities, as explained below.

[0009] The portion pack element may also be completely free of aluminum particles, although possible minimal contamination cannot be ruled out; such contamination may, for example, constitute no more than 0.01% by weight.

[0010] Firstly, the invention is based on the new discovery that, in addition to soot particles, aluminum particles, and especially aluminum pigments, can cause inadequate classification in waste sorting plants. The infrared radiation used in waste sorting plants is scattered by aluminum pigments, and this scattering can lead to misclassifications, either by assigning an incorrect material or by failing to assign a material. Misclassifications due to soot particles, on the other hand, arise from the absorption of the infrared radiation used by the soot particles.

[0011] It is a further finding of the invention that the improved classification in waste sorting plants is at least largely independent of the color choice for the capsule element, i.e. a white layer or in particular an inner white layer is not necessary to achieve the improved classification.

[0012] Studies have shown that, for otherwise aluminum-free capsule cups and capsule lids, a fairly reliable classification by near-infrared spectroscopy can be achieved up to approximately 0.4 percent by weight of aluminum pigments in the colorants of the capsule cup or capsule lid, with the weight proportion of the colorants in the capsule cup or capsule lid ("dosage") being between 4% and 22%, particularly between 6% and 18%; for example, for lids, between 6% and 18%, and for cups, between 11% and 17%.

[0013] The portion pack can be a portion capsule.

[0014] In embodiments, the portion pack element has the wall, i.e. a portion pack wall.

[0015] In embodiments, the portion pack element is a portion pack cup.

[0016] In other embodiments, the portion pack element is a portion pack lid. The portion pack lid can, in particular, be dimensionally stable and is therefore not a film, such as some portion packs use to close the portion pack cup.

[0017] In embodiments, the portion pack element is substantially free of Russpartikeln. This prevents misclassifications particularly well and enables particularly reliable classification.

[0018] “Substantially free from soot particles” means that the proportion (mass percentage) of Russpartikeln is at most 0.08%, i.e., the soot particle content is between 0 and 0.08%. Even soot particle contents of only about 0.01 percent by weight can make detection difficult. The portion pack element may also be completely free of soot particles—although possible minimal contamination cannot be ruled out; such contamination, for example, has a mass fraction of no more than 0.002%.

[0019] In embodiments, the first layer is substantially free of aluminum particles.

[0020] In embodiments, the first layer forms an outer layer of the portion pack element. The first layer can thus form an outer layer and / or an inner layer of the portion pack. In particular, the first layer can form an outer layer of the portion pack. Therefore, if the first layer comprises aluminum or, in particular, aluminum pigments, their weight fraction must be correspondingly low if it is to be substantially free of aluminum particles.

[0021] In embodiments, the first plastic material Polypropylen Due to its mechanical and thermal properties, polypropylene is ideal for the production of coffee capsule components (such as capsule cups and capsule lids). Polypropylene can generally be easily identified in waste sorting facilities using infrared spectroscopy.

[0022] In particular, the first plastic material can consist of at least 60 percent by weight, especially at least 70 percent by weight, polypropylene. It can in particular consist of at least 80 percent by weight or even at least 90 percent by weight, polypropylene.

[0023] For example, the portion pack element can consist of between 60 and 80 percent polypropylene by weight. The same can also apply to the portion pack.

[0024] In addition to the first layer, the portion pack element may also have one or more further layers, for example at least one layer of biodegradable material.

[0025] In embodiments, the portion pack element comprises a second layer made of a second plastic material, in particular wherein the second plastic material is a biodegradable material. In particular, the second layer can be adjacent to the first layer or connected to the first layer via a further, intermediate layer.

[0026] The second plastic material can, in particular, contain a polyvinyl alcohol copolymer, in particular a polyvinyl alcohol (PVOH), an ethylene-vinyl alcohol copolymer (EVOH), or a butenediol-vinyl alcohol copolymer (BVOH). These plastic materials can form an oxygen barrier, which is of great importance for the quality and storage stability of sensitive extraction materials such as coffee powder. Furthermore, these plastic materials are water-soluble, which contributes to their environmental friendliness. The second plastic material can, for example, contain at least 50 percent by weight, in particular at least 70 percent by weight, of a polyvinyl alcohol copolymer, for example one of the aforementioned (PVOH, EVOH, BVOH) or a mixture of at least two thereof. In other embodiments, the second plastic material contains between 1 and 5 percent by weight of such a polyvinyl alcohol copolymer.

[0027] In embodiments, the portion pack element contains between 1 and 5 percent by weight of such a polyvinyl alcohol copolymer. The same may also apply to the portion pack.

[0028] Embodiments of the invention are described below with reference to the drawings. In the drawings, like reference numerals denote like or analogous elements. They show: Fig. 1 a portion pack designed as a capsule in a side view; Fig. 2 a portion pack cup of the capsule according to Fig. 1 , in perspective view; Fig. 3 a portion pack cap of the capsule according to Fig. 1 , in perspective view; Figs. 4a bis 6b Classification images; Fig. 7 the gray levels used to encode the classification results.

[0029] Parts not essential to understanding the invention are sometimes not shown. The described embodiments are exemplary of the subject matter of the invention or serve to explain it and are not limiting.

[0030] The portion pack designed as capsule 1 according to Figur 1 It is essentially cube-shaped with rounded edges. However, its dimensions increase slightly towards the top, so that, strictly mathematically speaking, the capsule has the shape of a truncated pyramid. The angle of inclination of the lateral surfaces in the figure relative to the vertical (dashed line in Fig. 1 ) to the base is very small, preferably no more than 2°, for example, only about 1°. Furthermore, the height of the capsule above the base approximately corresponds to the length of the base edges.

[0031] The capsule 1 comprises a portion pack cup (or capsule cup) 1b and a portion pack lid (or capsule lid) 1a attached thereto along a circumferential collar. The capsule cup forms a capsule base and a circumferential side wall, which at its axial direction (parallel to the dashed line in Fig. 1 The capsule lid 1a is curved outwards, in that the lid surface, which is essentially parallel to the capsule base, is curved outwards (and axially 'vertically') compared to the surrounding collar, i.e. in Fig. 1 upwards, offset.

[0032] The capsule 1 is filled with an extraction material, for example coffee powder (in Fig. 1 not shown).

[0033] Figur 2 shows the capsule cup 1b before filling and before closing. The capsule cup collar has an extension that may be larger than that of the collar of the finished capsule.

[0034] Figur 3 shows a capsule lid 1a, which, like the capsule cup 1b, is manufactured, for example, by injection molding. The capsule lid 1a has a lid surface in a central area, a transition area forming a curvature, and a lid collar.

[0035] Capsules 1 of the Figur 1 drawn type, capsule cup 1b of the Figur 2 drawn type and capsule lid 1a of the Fig. 3 The type shown is already known from the prior art, for example from WO 2015 / 096990.

[0036] However, the portion packaging and portion packaging elements or portion packs (in particular capsules) and portion packaging elements (in particular capsule elements) described here are essentially free of aluminum particles.

[0037] During capsule production, a capsule element (capsule cup 1b) is first filled with the extraction material, and then another capsule element (capsule lid 1a) is positioned. Ultrasonic welding then takes place to seal the capsule airtight. Depending on the initial expansion of the capsule cup collar and the capsule lid collar, an optional trimming of the excess collar section may be performed after welding.

[0038] Because capsule elements are essentially free of aluminum particles, infrared light shone onto them is less scattered. This facilitates classification of the capsule elements in waste sorting facilities, where infrared spectroscopy, such as near-infrared spectroscopy, is used to identify different materials, particularly different polymer materials. For example, the capsule elements may have a polypropylene layer that can be identified in this way.

[0039] To be essentially free of aluminum particles, the capsule elements are either completely free of aluminum particles (except for unavoidable minor aluminum-containing contamination). Or they contain aluminum pigments, particularly in the polypropylene layer, but only in very small quantities. For example, the aluminum pigments each make up only 0.08% by weight of a capsule element.

[0040] Furthermore, the capsule elements are free of soot particles, which absorb infrared light and thus lead to misclassifications.

[0041] The effect that the classification based on infrared spectroscopy depends strongly on the content of aluminum particles was verified in experiments.

[0042] The Figuren 4a bis 6b show corresponding experimentally obtained classification images. The pattern fillings used for classification result coding are shown in Figur 7 shown: The two hatchings correspond to a correct classification (polypropylene was detected), the dot fillings are incorrect assignments to other plastics (PET or PA-6), for black areas it was not possible to assign the near-IR spectroscopy measurement results to a plastic.

[0043] In the experiments, a collection of portion pack elements in a waste sorting plant was examined using near-infrared spectroscopy; capsule cups in Figuren 4a bis 5b , capsule cup in Figuren 6a, 6b .

[0044] The portion pack elements contained a dye in a polypropylene layer. The polypropylene layer formed an outer layer of the respective portion pack element.

[0045] The portion pack elements were free of soot particles.

[0046] In Fig. 4a The dye contained 0.3% by weight of aluminum pigments, in Fig. 4b with otherwise identical properties, a weight fraction of 0.65% of aluminum pigments.

[0047] In Fig. 5a The dye contained 0.27% by weight of aluminum pigments, in Fig. 5b with otherwise identical properties, a weight fraction of 0.83% of aluminum pigments.

[0048] In Fig. 6a the dye contained 0% by weight of aluminum pigments, in Fig. 6b with otherwise identical properties, a weight fraction of 2.1% of aluminum pigments.

[0049] The weight proportion of the dye in the respective portion pack element was approximately 14% (dosage in the case of the capsule cups) or between 12% and 14% (dosage in the case of the capsule lids).

[0050] How Figs. 4a bis 6b clearly show, the lower weight proportion of aluminum pigments ( Figs. 4a, 5a, 6a ) a large proportion of correct classifications (hatched) are present, while with the higher weight proportion of aluminum pigments ( Figs. 4b, 5b, 6b ) there is a large proportion of misclassifications (dotted or black), namely either by assignment to another plastic (dotted) or because no plastic could be assigned (black).

[0051] From the experiments it can be concluded that it is advantageous to provide a weight fraction of aluminum pigments of no more than about 0.4% in the dye in order to achieve sufficiently good classifiability in a waste sorting plant.

[0052] From classification images such as those in Figs. 4a bis 6b A so-called valve mirror can be created using the method shown, on the basis of which valves in the waste sorting plant can be controlled in such a way that material located where the classification result is polypropylene can be separated out by means of an air blast.

Claims

1. Portion pack element for forming a wall of a portion pack for receiving an extraction material, comprising at least a first layer made of a first plastic material, wherein the portion pack element is substantially free of aluminum particles.

2. Portion pack element according to claim 1, which has a weight proportion of Aluminum of not more than 0.08%, in particular of not more than 0.05%.

3. Portion pack element according to claim 1 or claim 2, which has a weight proportion of Aluminum pigments of not more than 0.08%, in particular of not more than 0.05%.

4. Portion packing element according to one of claims 1 to 3, which is substantially free of soot particles.

5. Portion pack element according to one of claims 1 to 4, wherein the first layer forms an outer layer of the portion pack element.

6. Portion packing element according to one of claims 1 to 5, wherein the first plastic material comprises polypropylene, in particular wherein the first plastic material consists of at least 60% by weight, in particular at least 80% by weight, of polypropylene.

7. Portion pack element according to one of claims 1 to 6, comprising a second layer consisting of a second plastic material, wherein the second plastic material contains a polyvinyl alcohol copolymer, in particular at least 50% by weight.

8. Portion pack comprising a portion pack element according to one of claims 1 to 7, wherein the portion pack element is a capsule cup or a capsule lid.

9. Portion pack according to claim 8, containing an extraction material, in particular coffee powder, which is packaged airtight in the portion pack.

Images