Single-serve capsule

Abstract

A single-serve capsule (1) filled with an extraction material for producing a brewed product has a main body and also a lid (3), fastened on the main body, made of plastic material. The main body and lid together form a capsule which encloses the extraction material. The lid has a lid collar (42), the inner side of which is fastened on the main body. The lid has a substantially rectangular, in particular square, outline. An end-side, flat lid surface (31) of the lid is offset in an axially outward direction in relation to the plane defined by the lid collar. According to one aspect of the present invention, the lid has a stiffening structure with at least one inwardly projecting reinforcing rib (46). The reinforcing structure is designed here such that it spans the two lid-surface diagonals.

Description

[0001] PORTION CAPSULE

[0002] The invention relates to the preparation of beverages or the like from an extraction material contained in a capsule, for example, ground coffee. It particularly relates to a single-serve capsule.

[0003] Extraction devices for preparing beverages from a product contained in a single-serve container are known, for example, as coffee, espresso, or tea machines. In many such systems, the single-serve containers are designed as 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 expelled from the capsule on the second side. Depending on the beverage being prepared and the system, a considerable amount of pressure must be maintained inside the capsule.

[0004] WO 2010 / 118543 and WO 2015 / 096989 disclose single-serve coffee capsules which are approximately cube-shaped, made of plastic, and, unlike the known cup-shaped capsules, do not have a collar running around the plane of one (top) cover surface. Such a collar is required in capsule systems according to the prior art, among other things, for closing the capsule with a film serving as a lid. In contrast, WO 2010 / 118543 and WO 2015 / 096989 use a domed lid. The capsule produced according to the teaching of WO 2010 / 118543 therefore has a collar running around the planes defined by the cover surface, forming a collar, the extent / lateral protrusion of which, however, is significantly reduced compared to the collar of known capsules.For welding, an energy director is required, which is formed by a circumferential rib and can be present on the cup (according to WO 2010 / 118543) or on the lid (according to WO 2015 / 096989). The curved lid forms a flat lid surface, which is offset from the surface in which the lid collar runs, with a transition area forming a curvature between the lid collar and the flat lid surface.

[0005] EP 3 907 145 and EP 2 889 244 each show a single-serve coffee capsule of the type shown in WO 2010 / 118543 and WO 2015 / 096989, in which the curved lid has an energy director of the aforementioned type before the capsule is closed. Furthermore, in some embodiments, an inwardly projecting web is formed on the edge of the flat lid surface—that is, at the transition between the flat lid surface and the transition region. This web serves as mechanical reinforcement and—due to its position at the edge of the flat lid surface—as a stacking aid.

[0006] Aluminum and plastics, such as polypropylene, have become particularly well-known capsule materials. So-called bioplastics have also been discussed as capsule materials. On the one hand, these refer to plastics made from renewable raw materials (so-called bio-based plastics). On the other hand, bioplastics refer to plastics that are biodegradable (so-called biodegradable plastics). The plastics proposed for the production of portion capsules are biodegradable and sometimes contain a proportion of bio-based plastics. In this text, "biodegradable" means biodegradable according to the ENI 3432 standard (as of the end of 2020), and "biobased" means "made from renewable raw materials, not fossil-based."

[0007] EP 3 922 578 relates to a capsule made of a composite material, with a capsule cup with reinforcing ribs

[0008] Plastic capsules of the type described in WO 2010 / 118543, WO 2015 / 096989, EP 3 907 145, and EP 2 889 244 have proven successful. However, their production involves a certain amount of effort. One of the key manufacturing challenges is attaching the lid to the base body filled with the extraction material, particularly by ultrasonic welding. Since the lid is a dimensionally stable, three-dimensional body and not merely a film, it must first be produced using a molding process and then precisely positioned relative to the base body for attachment. This requires, among other things, that the lids be individually inserted into the welding system, which is quite time-consuming and increases the manufacturing costs of the entire capsule.

[0009] It is an object of the present invention to remedy this situation.

[0010] This problem is solved by the invention as defined in the patent claims.

[0011] A portion capsule filled with an extraction product for the production of a brewed product comprises, in a manner known per se, a base body, generally made of plastic, and a plastic lid attached thereto. The base body and lid together form a capsule enclosing the extraction product. The base body forms a base region, a circumferential side wall, and a circumferential base body collar adjoining the circumferential side wall towards one side of the lid. The lid has a lid collar, the inside of which is attached to the base body collar, e.g., welded to it. The capsule has a substantially rectangular, in particular square, outline, in that both the base body and the lid have a substantially rectangular, in particular square, outline, at least in the area of ​​the collar.

[0012] The capsule as a whole can in particular be approximately cube-shaped.

[0013] The lid is not flat, but rather curved outwards (relative to the interior of the capsule), i.e., axially outward. This means that a flat (axial) end lid surface is offset axially outwards from the plane defined by the collar. The lid is therefore different from a flat, e.g., film- or plate-like lid element. It is a three-dimensionally shaped body. In other words, the lid forms a curvature, so that it contributes to the capsule volume by offsetting the lid surface relative to the lid collar.

[0014] According to one aspect of the present invention, the lid has a stiffening structure with at least one inwardly projecting reinforcing rib. The reinforcing structure is designed such that it spans the two diagonals of the lid surface.

[0015] The reinforcing rib is located primarily on the lid surface, i.e., it protrudes inward from the lid surface. "Protruding inward" here means "protruding toward the interior of the capsule."

[0016] The reinforcing rib is designed in such a way that it increases the rigidity of the cover surface, which is not the case, for example, with structures known from the aforementioned prior art.

[0017] The fact that the diagonals are "spanned" means that at least one reinforcing rib passes through the diagonals, i.e. runs from one side of the diagonal to the other side of the diagonal, and not just along the edge of the lid surface, but at a significant distance (e.g. at least 5% of the length of the diagonal, or at least 10%) from the corners. With a length of the diagonal through the lid surface of 30-40 mm, for example, the diagonals can be spanned in at least two places, each at a distance of at least 3 mm or at least 5 mm from the corner, and / or in the middle of the diagonals. If the corners are rounded or bevelled, this distance is measured from the effective, real edge of the lid surface and not from the corner in the mathematical sense.

[0018] The fact that the lid surface diagonals are spanned also means that the reinforcing rib does not only run along the edge of the lid surface, but also inside the lid surface.

[0019] It has been shown that such a reinforcement structure is advantageous for the industrial production of capsules. Such a reinforcement structure prevents the lids from being bent during transport to the plant where the capsules are manufactured from the lids, the base bodies, and the extraction material. The finding is that, firstly, deformations of capsule lids with the shape described here, with a rectangular footprint and a lid surface offset from the collar, primarily occur as deformations along a diagonal. This can be prevented by the reinforcement structure spanning the two diagonals. However, sufficient flexural rigidity is present along the side lengths due to the design.Secondly, it is the realisation that it is such deformations that represent an obstacle to efficient industrial production: they prevent a large number of covers from being inserted into the welding system as a bundle.

[0020] The shape of the cover will generally consist of the cover collar, a curved transition area, for example, and the cover surface as a central flat area, from the radial outside to the radial inside. The transition area defines the offset between the axial positions of the collar and the cover surface, i.e., it runs approximately vertically (if the horizontal is defined by the cover surface), but certainly not perpendicular to axial directions.

[0021] "Flat" here refers to the outer surface - the reinforcing structure and any other inward-projecting structures represent deviations from the flat shape. Relief-like lettering or similar designs may also be applied to the flat lid surface on the outside.

[0022] The transition area can, for example, be curved in an S-shape or extend continuously from an outer section at an angle to the collar plane to the central, flat lid surface. The dimensions are selected, for example, so that the central, flat area (the lid surface) visually dominates, for example, by being the same size as or only slightly smaller (e.g., a maximum of 10%) than the base area of ​​the capsule. In particular, it can be provided that this flat area occupies more than 60% of the diameter and accordingly at least 40% of the area.

[0023] The shape of the reinforcement structure can be adapted, in particular, to the geometry of the piercing device, which specifically perforates the capsule on the lid side during the extraction process. The reinforcement rib(s) can be present, in particular, where no piercing spike perforates the lid.

[0024] The reinforcing ribs can be attached, in particular, to the transition area and / or form a completely circumferential structure, for example, a ring around a center or even a polygon around the center. In the first case (attachment to the transition area), the reinforcing ribs are supported against the structurally rigid edge of the capsule lid. In the second case, they form an inherently rigid structure.

[0025] Examples of reinforcing structures include a pair of reinforcing ribs running diagonally between the corners (the two diagonals are spanned by the reinforcing rib running along the other diagonal), a pair of reinforcing ribs running centrally parallel to the sides (the diagonals are spanned by both reinforcing ribs), or reinforcing ribs spanning the diagonals along the corners and connected to the transition area at both ends. Another example is an annular reinforcing rib. Combinations of these concepts are readily possible.

[0026] The lid can be manufactured, in particular, by injection molding, which also applies to the base body. A manufacturing process for the capsule can therefore comprise the following steps: manufacturing the base body by a shaping process (shaping processes here include both primary forming processes such as injection molding and forming processes such as deep drawing); manufacturing the lid by injection molding, whereby the mold is designed such that, in addition to the lid collar, the transition region and the lid surface, the reinforcement structure and, for example, an energy director are produced; filling the base body with the extraction material, e.g., ground coffee; fastening the lid to the base body so that the lid collar is connected to the base body collar, for example, by ultrasonic welding; optionally separating an outer part of the collar, which results from the connection of the base body collar and the lid collar.

[0027] In this text, "radial" and "axial" always refer to the capsule's axis, which runs through the center of the capsule and perpendicular to the plane defined by the collar (and generally also to the plane of the capsule base and the lid surface). This axis is also related to the capsule's function: During brewing, the liquid flows axially, i.e., from the capsule base to the capsule lid (or vice versa). "Radial" directions are perpendicular to the capsule's axis. "Radial" therefore does not imply a round capsule outline.

[0028] In embodiments, the base body and / or lid can be present, for example, as a multi-layer system with bioplastic (e.g., Ecovio) / PVOH / bioplastic, with PVOH forming the diffusion barrier layer. Particularly for thermoformable layer systems, a so-called tie layer, i.e., an adhesive layer, can be arranged between the PVOH layer and the bioplastic, so that the structure can then be bioplastic / tie / PVOH / tie / bioplastic. Biodegradable tie layers are now known and commercially available, e.g., as natural waxes. As an alternative to the bioplastic design, the base body and lid can also be made of another plastic—e.g., with a diffusion barrier layer—e.g., polypropylene.

[0029] The plastic material of the lid and the base body can be identical. However, it is also possible for the lid to be made of a different plastic composition, which can be welded to the base body plastic.

[0030] The wall thickness in the area of ​​the base body is, in particular, between 0.2 mm and 0.5 mm, for example, between 0.25 mm and 0.45 mm. The wall thickness of the lid can be between 0.25 mm and 0.55 mm, for example, between 0.35 mm and 0.45 mm. In one embodiment, the wall thickness of the lid approximately corresponds to the wall thickness of the base body.

[0031] The capsule can—this applies to all embodiments, including the first aspect—be designed in particular such that the base body and the lid together completely enclose the extraction material, without an opening covered, for example, by a film or the like. It can, in particular, be hermetically and oxygen-tight, for example, by having a suitable diffusion barrier.

[0032] Embodiments of the invention are described below with reference to drawings. In the drawings, like reference numerals designate like or analogous elements. The drawings are not to scale and show partially corresponding elements in different sizes from figure to figure. They show:

[0033] Fig. 1 shows a capsule; - Fig. 2 shows a base body for the production of a capsule according to Fig. 1;

[0034] Fig. 3 a lid;

[0035] - Fig. 4 shows a lid according to the prior art seen from the inside; and

[0036] - Fig. 5 a lid with reinforcing structure;

[0037] - Fig. 6 another cover with reinforcing structure;

[0038] - Fig. 7 a lid according to a further embodiment;

[0039] - Fig. 8 a variant of the lid from Fig. 7;

[0040] - Fig. 9 a lid according to another embodiment; and

[0041] - Fig 10 and 11 each show a sketch of two further variants.

[0042] The capsule 1 shown in Figure 1 essentially has the shape of a cube with rounded edges. However, its dimensions increase slightly toward the top, so that, strictly mathematically speaking, the capsule has a truncated pyramid shape. The angle of inclination of the lateral surfaces in the figure relative to the perpendicular to the base surface 5—of course, this refers to the plane perpendicular to the base surface and passing through the edge between the base surface and the corresponding lateral surface—is very small, preferably no more than 2°, for example, only approximately 1°. Furthermore, the height of the capsule above the base surface approximately corresponds to the length of the base surface edges.

[0043] The capsule comprises a base body (or cup) 2 and a lid 3 attached thereto along a circumferential collar 4. The base body forms a capsule base 5 and a circumferential side wall 6, which is closed off at its outer end in relation to the axial direction (axis 10), the upper end in the figure, by the collar 4. The lid is curved outwards in that the lid surface 9, which is essentially parallel to the capsule base 5, is offset outwards (and axially 'vertically') compared to the circumferential collar 4, i.e., upwards in Fig. 1.

[0044] Figure 2 shows the base body 2 (cup) before filling and before closing. The base body collar 41 has an extension that may be larger than that of the collar 4 of the finished capsule.

[0045] Figure 3 shows a lid 3, which, like the base body 2, is manufactured, for example, by injection molding. The lid has a lid surface 31 in a central region, a transition region 32 forming a curvature, and a lid collar 42.

[0046] Capsules of the type shown in Figure 1, base body 2 of the type shown in Figure 2 and lid 3 of the type shown in Figure 3 are also already known from the prior art, for example from WO 2015 / 096990.

[0047] During capsule production, the base body 2 is first filled with the extraction material, and then the lid 3 is positioned. Ultrasonic welding then takes place. Depending on the initial expansion of the base body collar and the lid collar, an optional trimming of the excess collar section may be performed after welding.

[0048] Figure 4 shows a lid 3 of the type shown in Figures 1 and 3 from the inside. The lid according to Figure 4 is not designed according to the invention and has no reinforcing structure. It has been shown that such a lid can be bent during transport, with bending generally occurring along one of the two diagonals (a diagonal 51 is shown in Figure 4; the bend along this diagonal 51 is indicated by block arrows), while bends with bending axes parallel to the sides are prevented by the rigidity caused by the transition region 32 forming a curvature, i.e. being curved away from the plane of the lid surface 31.

[0049] Figure 5 shows a lid 3 with a reinforcement structure. This reinforcement structure is formed by two reinforcement ribs 46, each running diagonally and connected to each other in the center of the capsule lid. The two diagonals are thus spanned by the reinforcement rib running along the other diagonal. The reinforcement ribs are also connected to the transition area 32, resulting in a particularly stable structure overall.

[0050] In the illustrated embodiment, the height of the ribs (i.e., their axial extension) corresponds to the height of the lid's curvature. However, this is not required. It is also possible to make the ribs shorter or taller; in the latter case, the ribs can also have a centering effect during the capsule's manufacturing process, in addition to stiffening.

[0051] In the variant according to Figure 6, two crossed reinforcing ribs 46 are also present. The reinforcing ribs 46 also extend to the transition region 32 and are connected to it. In contrast to the embodiment of Figure 5, however, the reinforcing ribs are parallel to the sides and not diagonally. In Figure 6, the diagonals 51 spanned by the reinforcing ribs 46 are also shown schematically. Figure 7 shows an embodiment with four reinforcing ribs 46, each connecting the two sides formed by the transition region that converge at a (rounded) corner. Such peripheral reinforcing ribs 46 span the diagonals 51 and accordingly counteract bending along the diagonals. Figure 7 also illustrates the distance a at which the reinforcing ribs span the diagonals 51 (in the embodiments of Figure 5).5 and 6, the distance a corresponds to half the length of the diagonals, since these are spanned exactly in their middle).

[0052] The variant according to Figure 8 differs from the embodiment of Figure 7 in that the reinforcing ribs are bent radially outward. This does reduce the stiffening effect somewhat compared to straight ribs connecting the sides, as shown in Figure 7. However, the reinforcing ribs can be sufficient and have the advantage that the central region of the lid surface 31, which is not provided with ribs, has a larger radial extent, so that such embodiments also allow closely spaced piercing domes across almost the entire lid surface. Figure 8 also illustrates the distance a at which the reinforcing ribs span the diagonal.

[0053] Finally, Figure 9 shows an embodiment with a single, annular reinforcing rib 46. Although this rib is not attached to the transition area, its annular design makes it inherently stable. It is suitable, for example, for brewing modules in which at least one piercing dome is present both inside and outside the ring formed by the reinforcing rib.

[0054] Combinations of the concepts in Figures 5-9 are also conceivable. Figure 10 schematically outlines, for illustration and as one of many possible examples, a possible structure of connected reinforcing ribs 46 with reinforcing ribs running along the diagonal but not extending to the center, and a central annular reinforcing rib. In contrast to the embodiment in Figure 5, this also allows for the arrangement of a central piercing mandrel. Figure 11 outlines a variant with a combination of the concepts in Figures 8 and 9. Other combinations are also possible, as are other concepts, e.g., with hashtag-like reinforcement ribs, a square structure instead of the annular reinforcement rib (or in addition to it), irregular structures, etc.

Claims

PATENT CLAIMS Portion capsule (1) filled with an extraction material for the production of a brewed product, comprising - A base body (2) made of plastic, with a base region (5), a circumferential side wall (6) and a circumferential base body collar (41) adjoining the circumferential side wall towards a lid side; and a lid (3) made of plastic, with a circumferential lid collar (42), - wherein the base body (2) and the cover (3) have a substantially rectangular outline in the region of the collar (4), - wherein the lid (3) forms a flat lid surface (31) which is offset from a surface defined by the lid collar (42); - wherein the cover surface (31) also has a rectangular plan, so that two diagonals (51) are defined; - wherein an inner side of the lid collar (42) is fastened to the base body collar so that a common collar (4) is formed; - and wherein the base body and the lid enclose a capsule interior containing the extraction material; characterized in that the lid (3) has a stiffening structure with at least one reinforcing rib (46) projecting towards the capsule interior, wherein the stiffening structure spans both diagonals (51).

2. Portion capsule according to claim 1, wherein the lid (3) has, from radially outside to radially inside, the lid collar (42), a curved transition region (32) and the lid surface (31) as a central, flat region.

3. Portion capsule according to claim 2, wherein the reinforcing structure extends to the transition region (32) and is connected to it.

4. Portion capsule according to claim 3, wherein the reinforcing structure has a plurality of reinforcing ribs (46) extending between two ends, each of which is connected to the transition region at both ends and each spans a diagonal (51).

5. Portion capsule according to one of the preceding claims, wherein the Reinforcing structure comprising a plurality of reinforcing ribs (46) which extend from an edge of the cover surface (31) towards the centre and which are connected to one another.

6. Portion capsule according to claim 5, comprising two reinforcing ribs (46) crossing in the middle of the lid surface and running diagonally or parallel to the sides of the lid surface (31).

7. Portion capsule according to one of the preceding claims, comprising a reinforcing rib (46) extending annularly around a center of the lid surface (31).

8. Portion capsule according to one of the preceding claims, wherein the lid (3) is produced by injection molding.

9. Portion capsule according to one of the preceding claims, wherein the lid (3) is welded to the base body (2).

10. Production of a portion capsule according to one of the preceding claims, comprising the steps: • Production of the base body by a forming process; • Production of the lid by injection molding, wherein the mold is designed so that in addition to the lid collar (42), the transition area (32) and the lid surface (31), the reinforcement structure; • Filling the base body with the extraction material; • Fastening the cover (3) to the base body (2) so that the cover collar (42) is connected to the base body collar (41).

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