Capsule with lid for beverage preparation

Abstract

The present invention relates to a capsule 1 for preparing a beverage, said capsule comprising: a body 2 forming a cavity with an opening surrounded by a rim 5, said cavity being adapted to receive contents for preparing the beverage, the rim 5 comprising an inner portion and an outer portion, and a lid 7 welded to the rim 5 by means of: a continuous weld on the outer portion of the rim, the continuous weld surrounding the opening; tack welds on the inner portion of the rim, each tack weld being spaced at a minimum distance greater than a predetermined threshold from other tack welds on the inner portion; and the continuous weld. Figure for the abstract: Figure 2

Description

Title of the invention: Capsule with lid for preparing beverages. TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to the field of single-use, biodegradable and compostable closed capsules, suitable for industrial and / or home or methanizable composting, containing at least one edible substance. The edible substance may be in powder form for preparing a beverage, for example coffee, intended to be extracted under pressure and / or temperature, or in liquid form for preparing a beverage, for example lemonade or food supplements, intended to be extracted at low pressure and low temperature or at room temperature. STATE OF THE ART

[0002] Pre-measured and pre-packaged coffee portions are widely used to prepare espresso-type coffees because they are simple and easy to use.

[0003] There are generally two types of capsules on the market: rigid capsules, typically consisting of a container or capsule body and a lid, and flexible capsules containing filter layers. The present invention relates to the first category of capsule.

[0004] Rigid capsules of the Nespresso® type are widely used in Europe. These capsules comprise a body or container and a lid which are traditionally made essentially of aluminum.

[0005] The process of delivering the final beverage follows the following scheme: a fluid, such as water or milk, is injected into the capsule to interact with the substance contained in the capsule in order to produce the desired beverage, and when a sufficient amount of fluid fills the capsule, the latter opens under the pressure of the fluid to release the prepared beverage.

[0006] For example, the capsule can be opened by pressing an extraction face of the capsule against an opening structure provided in the capsule holder, such that the extraction face is torn when it reaches a breaking stress on the holder. The opening structure can consist of a number of raised and recessed elements, for example, pyramidal elements, over which the extraction face is stretched and torn by the internal pressure of the fluid. Such a controlled-pressure beverage preparation has the advantage of producing a high-quality beverage.

[0007] Biodegradable or compostable capsules also exist, meaning that the lid and body are made of biodegradable and / or compostable materials, whether through industrial composting and / or single-use home or methanogenic composting. Biodegradable or compostable capsules also consist of a capsule body and a lid. The lid is welded to the body and generally to a suitable part of the body forming a circular rim.

[0008] Biodegradable capsules of the prior art have the disadvantage of being more fragile, particularly at the welding area between the capsule lid and the circular rim of the capsule.

[0009] Indeed, biodegradable and / or compostable lids are not made of aluminum like conventional capsules. These biodegradable and / or compostable lids are often made of a laminate (also called a multilayer) whose layers are bonded together with an adhesive. The adhesive, as well as certain layers of the laminate, may exhibit thermal sensitivity that weakens them during the welding of the lid to the circular rim of the capsule.

[0010] Thus, the weakening of the operculum at the welding zone can lead to degradation of the operculum, degradation which is accentuated by additional stresses: - Constraints that the capsule undergoes during manufacturing, and / or - Internal pressure of the capsule related to the capsule's contents, for example, during coffee degassing, and / or - variation in ambient temperature; - variation in ambient humidity; - Etc.

[0011] Damage to the seal can lead to a loss of airtightness of the capsule or even to its opening. This can result in damage to the capsule's contents (for example, oxidation of the contents) or even a release of the capsule's contents.

[0012] The applicant has therefore developed a new biodegradable or compostable capsule which overcomes the problems of the prior art while maintaining good oxygen and moisture tightness. Summary of the invention

[0013] The present invention relates to a capsule for preparing a beverage, said capsule comprising:

[0014] a body forming a cavity with an opening surrounded by a rim, said cavity being adapted to receive contents for preparing the beverage, the rim comprising an inner portion and an outer portion, and

[0015] a lid welded to the rim by means of: - of a continuous weld on the outer portion of the rim, the continuous weld surrounding the opening; - of weld points on the inner portion of the rim, each weld point being spaced at a minimum distance greater than a predetermined threshold: • other welding points of the inner portion; • continuous welding.

[0016] By capsule for the preparation of a beverage, it is understood that any consumable in the form of a capsule which allows, by means of a device adapted to receive the capsule, for example an espresso coffee maker, the beverage to be prepared.

[0017] The capsule body is understood to be a container for receiving the preparation used to make the beverage. Such a body may be made of a more or less rigid material and may have a variable shape. The shape of the body depends on the recess provided in the device designed to receive the capsule. The most common shapes are frustoconical, hemispherical, or spherical, as seen in the capsules manufactured by Nespresso. The invention is not limited to such shapes and can be applied to any body shape including a rim for sealing a lid. For example, the body may be cubic or cylindrical.

[0018] By cavity is meant an enclosure allowing the quantity of contents necessary to prepare the drink to be placed.

[0019] By "opening surrounded by a rim," it is understood that the body forms a lip around the entire perimeter of the opening. The rim forms a surface for sealing the lid to close the opening. The rim may additionally butt against the recess provided in the device adapted to receive the capsule, hereafter referred to as the capsule holder. This ensures that the capsule is held firmly during the preparation of the beverage and, potentially, during the pressure build-up within the capsule, for example, in the case of a coffee capsule.

[0020] This surface can preferably be substantially in the same plane, this plane being perpendicular to the direction of the opening (or parallel to the surface of the opening). In other words, from a front view relative to the opening, this surface is also frontally positioned. This is notably the case for commonly sold capsules. Thus, in the case of commonly sold capsules, whose body shape is frustoconical, hemispherical, or spherical, the rim is circular and has the form of a flat circular collar a few millimeters wide. In the frustoconical case, the body comprises a base and a side wall having a circular rim. The rim can have a width ranging from 1 to 4 mm. However, the invention is not limited to this type of "flat" rim.

[0021] The surface formed by the rim surrounding the opening, or more simply the rim surrounding the opening, can be subdivided into zones or portions, specifically an inner zone or portion and an outer zone or portion. The inner and outer portions each surround the opening; that is, they each go around the opening. The inner portion is between the opening and the outer portion. The two portions do not overlap. The combined area formed by the outer portion and the inner portion can be considered the surface formed by the rim.

[0022] The operculum allows the cavity to be closed. The operculum has dimensions such as to cover the opening as well as the rim of the capsule.

[0023] By welding, we mean a fusible material that has undergone a welding treatment or action enabling it to join two elements together, namely the lid and the capsule body. The fusible material may be present within one of the layers of the lid, directly on the inner part of the lid, or be a layer of the lid itself (for example, the inner layer). The fusible material may be, for example, PLA (polylactic acid), PHA (polyhydroxyalkanoates), PHB (polyhydroxybutyrate), PBS (polybutylene succinate), PBAIT (polybutylene-co-aliphate-co-terephthalate), PBAT (polybutylenadipate-terephthalate), or a hot melt adhesive.

[0024] A continuous weld is understood to be a weld in which the treated fusible material (i.e., molten material) forms a single unit without any discontinuity separating the weld in two. In other words, it is possible to move from one point of the continuous weld to another point of the continuous weld without encountering any discontinuity, that is, any area where the liner and the rim are not joined or should not be joined (in the event that the weld has deteriorated). For example, fusible material forming a circle around the opening is a continuous weld. The continuous weld can be, for example, 0.3 mm to 1.5 mm wide, or, for example, represent between 10% and 50% of the rim width.

[0025] By continuous weld surrounding the opening it is understood that it is possible to go around the opening by following the weld without encountering any discontinuity.

[0026] A spot weld is understood to be a weld in which the fusible material being treated is concentrated on a small surface. For example, concentrated within a disc with a diameter of less than 5 mm, or less than 3 mm, or less than 1.5 mm, or concentrated within a rectangle with a diagonal of less than 15 mm, or less than 10 mm, or less than 5 mm. The spot weld can have any shape, for example, rectangular, square, round, etc. Spot welds can form a discontinuous or dashed weld line.

[0027] By minimum distance is understood to mean the shortest length between two weld points or between a point on a surface and a weld point or between a weld point and a continuous weld. Since the weld points and the continuous weld represent a surface, it is possible to measure several different lengths between two weld points, a point on a surface and a weld point, or a weld point and a continuous weld; the shortest of these represents the minimum distance.

[0028] By threshold is understood to be the value of a length.

[0029] Continuous welding on the outer portion of the rim, that is, on only part of the rim and not across its entire width, ensures a tight seal of the lid while preventing damage to the lid when it is sensitive to the welding process. For example, the lid, a layer of the lid, or an interlayer binder may be temperature-sensitive and degrade or melt when the thermal energy input during welding is too high. For example, degradation of the binder layer can lead to a loss of adhesion between the layers and therefore potentially a loss of seal when the barrier layer loses its adhesion to the inner layer (when the barrier layer is not the inner layer) and thus to the rim of the capsule.More generally, the effect of internal pressure (for example, the release of coffee) from the capsule can lead to delamination of the layers, which can result in a loss of function of the layers, for example, a loss of seal.

[0030] Thus, when continuous welding is performed across the entire width of the rim, the weld is carried out over a larger portion of the rim, resulting in greater heat transfer from the welding tool or welding head to the lid, and the dissipation of thermal energy within the body or lid becomes more difficult. In this case, the lid will accumulate a significant amount of thermal energy, leading to its degradation. Conversely, when continuous welding is performed on the outer portion of the rim, the input of thermal energy and its accumulation at the lid is reduced, which also reduces the risk of damaging the lid. Since the continuous weld is continuous and encircles the opening, it ensures the lid's seal.However, even though welding damages the lid less, the continuous weld, being narrower, may prove insufficient given the stresses it undergoes. For example, the pressure inside the capsule can generate pull-out forces on the lid sufficient to at least partially detach the continuous weld. Stresses can also be related to the capsule's production process. Furthermore, the capsule's geometry can result in higher stresses at some points along the continuous weld than others. For example, a cubic capsule with a square rim would exhibit greater stress on the continuous weld at the rim's corners. Therefore, additional weld points are created to compensate for this. The mechanical fragility of the continuous weld is a concern. These weld points are spaced a certain distance apart from each other and from the continuous weld to prevent excessive heat buildup that could damage the lid. Thus, the conventional continuous weld, applied across the entire (or a significant portion) of the rim's width and damaging the layers and the binder of the lid's layers, is replaced by a combination of a thinner continuous weld with reinforcing weld points. This prevents damage to the lid during welding while maintaining acceptable mechanical properties for bonding the lid to the capsule body.

[0031] According to one embodiment, for each point p of the inner portion of the rim there is a weld point of the inner portion spaced with the point p by a minimum distance less than a second predetermined threshold.

[0032] This allows for a high density of weld points in the inner portion to support the stresses which would otherwise weigh on the continuous weld or affect the weld points to the point of potentially causing them to unweld.

[0033] By point p of the inner portion, it is understood that any point on the surface is independent of the weld points.

[0034] According to one embodiment, the outer portion comprises an inner sub-portion and an outer sub-portion, and in which the continuous weld is on the inner sub-portion.

[0035] The outer portion of the surface formed by the rim surrounding the opening, or more simply, the rim surrounding the opening, can also be subdivided into two sub-zones or sub-portions, namely an inner sub-zone or sub-portion and an outer sub-zone or sub-portion. The inner and outer sub-portions each surround the opening; that is, they each go around the opening. The inner sub-portion is located between the inner and outer sub-portions. The two sub-portions do not overlap. The combination of the outer and inner sub-portions can be considered the outer portion.

[0036] This simplifies manufacturing, particularly the welding of the lid, because if there is a misalignment of the welding head, the continuous weld can partially extend beyond the rim and thus fail to perform its function of holding the lid in place. The manufacturing process for such a capsule is therefore more forgiving.

[0037] According to one embodiment, the lid welded to the rim is also welded by means of tack welds on the outer sub-portion, each tack weld of the outer sub-portion being spaced at a minimum distance greater than a third predetermined threshold: of the other weld points of the outer sub-portion; of the continuous weld.

[0038] By placing weld points on the outer sub-portion, it is possible to protect the continuous weld from stresses applied to the edge of the lid. For example, these weld points protect the continuous weld against tearing actions by the edge of the lid.

[0039] According to one embodiment, the weld points are of one or a combination of the following shapes:

[0040] - circular;

[0041] - polygonal;

[0042] - rectangular, the rectangular-shaped points being arranged in one direction perpendicular to the rim and / or the rectangular points being arranged in a direction tangential to the rim;

[0043] - square.

[0044] By shape of weld points, it is understood that the shape of the weld points seen according to the direction of the opening, that is to say the shape that the weld points represent on the rim.

[0045] These shapes make it possible to simplify the manufacture of the capsule by simplifying the tools needed for welding while allowing good resistance of the weld points.

[0046] According to one embodiment, the surface of the edge or at least a part of the surface of the rim has a roughness greater than a predetermined value Ra.

[0047] This roughness value can be between 2.8 pm and 10 pm, advantageously between 3.5 pm and 8 pm or preferably between 5 pm and 6.3 pm.

[0048] The portion of the rim surface with such roughness can form a ring around the opening. The total width of this portion of the rim surface can represent between 1 / 3 and 2 / 3 of the rim width. Alternatively, the entire rim surface may exhibit such roughness.

[0049] This roughness is present before the welding of the lid onto the rim.

[0050] This allows for better adhesion of the weld points and continuous welding on the edge.

[0051] According to one embodiment, the lid is a laminate comprising:

[0052] - an inner layer comprising fusible material; and

[0053] - at least one other layer;

[0054] the inner layer being disposed between the body comprising the rim and at least one other layer.

[0055] This simplifies the manufacture of the capsule. Indeed, closing the capsule with the lid does not require the addition of fusible material during the lid welding operation, which greatly simplifies the welding operation.

[0056] The at least one layer may be one or more other layers, for example, a barrier layer, a filter layer, etc. The barrier layer makes the capsule, at least to some extent, impermeable to moisture, water vapor, and oxygen, thus ensuring good preservation of the capsule's contents. This layer is pierced during the beverage preparation process, for example, by pressing the capsule's extraction face (i.e., the foil) against an opening structure provided in the capsule holder or simply by the mechanical action of points or needles. The barrier layer may also be the inner layer. For example, the inner layer may be formed entirely or partially from a fusible material with sealing properties.

[0057] The filter layer keeps the solid contents of the capsule inside during the beverage preparation process. For example, the filter layer keeps the ground coffee beans inside the capsule during the beverage preparation. The filter layer can also be the inner layer. For example, the inner layer can be a non-woven fabric made entirely or partially of fusible material.

[0058] One or both layers may be present in the operculum.

[0059] According to one embodiment, the adjacent layers of the laminate are agglomerated with a binder.

[0060] This helps maintain the structure of the laminate. Maintaining the laminate's structure is important to allow the layers to fully perform their functions. Thus, if the barrier layer is no longer in contact with the other layers of the laminate, particularly at the continuous weld, air and moisture can infiltrate through the other layers and enter the capsule.

[0061] By "intermediate layer" is understood to mean two layers in contact. By "binder" is understood to mean an adhesive. The binder may be an adhesive suitable for food contact and advantageously chosen from acrylic adhesives.

[0062] According to one embodiment, the body and / or the lid are made up of at least 85% by weight of biodegradable and / or compostable (aerobic biological process) and / or methanizable (anaerobic biological process) materials, preferably made up of at least 95% by weight of biodegradable and compostable (aerobic biological process) and / or methanizable (anaerobic biological process) materials.

[0063] By “biodegradable” we mean a material capable of decomposing under the action of living organisms, such as bacteria, fungi or algae, to transform itself for example into carbon dioxide, water and / or methane.

[0064] By “compostable” we mean an object made with a biodegradable material capable of disintegrating under controlled conditions such as, for example, those defined by industrial and domestic compostability standards.

[0065] The capsules according to the invention advantageously meet the EN 13432 compostability standard, they are therefore said to be biodegradable under industrial composting conditions.

[0066] The EN 13432 standard specifies the technical requirements and procedures for determining the compostability of a material.

[0067] The EN 13432 standard defines the characteristics that a material, a product, must possess in order to be considered compostable and biodegradable.

[0068] Biodegradation can be tested according to standards such as ISO 14855, ISO 17556 or ISO 14851. For example, one of these tests requires that, in order to be considered "industrially compostable" - at least 90% of the material must be biologically degraded under controlled conditions within six months.

[0069] Similar tests also exist to allow for the certification of home composting. Currently, there are no international or European standards, only national standards, for home composting. Thus, the capsules according to the invention are biodegradable under home composting conditions according to French recommendations. In particular, they comply with standard NF T51-800 (2015), namely that at least 90% of the capsule is biodegraded under controlled conditions in less than 365 days (maximum 12 months) at 25°C + / - 5°C. The capsules (body and / or lid) according to the invention will also typically comply with Australian standard AS 5810 (2010).

[0070] Any composting process can be used, including industrial composting and / or domestic or methanizable single-use composting.

[0071] The biodegradable and / or compostable materials of the lid and / or body layers are preferably chosen from paper, non-wovens, cellulose, SiOx layers, biopolymers for example polylactic acid (PLA), polyhydroxyalkanoates (PHA), polybutylenadipate-terephthalate (PBAT), polybutylene-co aliphate co-terephthalate (PBA1T), polybutylensuccinate (PBS) hybrid layers of organic polymer and inorganic fibers, layers coated with polyvinyl alcohol or ethylene-vinyl alcohol copolymer.

[0072] The invention further relates to a method for manufacturing a capsule according to the invention, comprising the following steps:

[0073] - filling the cavity with the contents to prepare the drink,

[0074] - application of a welding head to the operculum to close the cavity and form the capsule,

[0075] in which the weld head includes projections corresponding to the weld points and the continuous weld.

[0076] The term "welding head" refers to a head that welds the fusible material of the lid. The welding head transfers heat (or ultrasound) to the lid, causing the fusible material to melt.

[0077] The welding head includes projections that come into direct contact with the seal and thus concentrate the heat transfer (or ultrasonic transfer) to the seal at the level of these projections. The projections are positioned according to a pattern corresponding to the spot welds and the continuous weld. Thus, the projections on the welding head are positioned opposite the locations where the fusible material must be treated to obtain the spot welds and the continuous weld according to the invention when the welding head is applied to the seal, which is itself placed on the rim.

[0078] The invention further relates to a method for manufacturing a capsule according to the invention, comprising the following steps:

[0079] - manufacturing the body of the capsule in order to obtain projections on the rim corresponding to the weld points and continuous welding,

[0080] - filling the cavity with the contents to prepare the drink,

[0081] - application of a welding head to the operculum to close the cavity and form the capsule.

[0082] In this embodiment, the welding head has a head without protrusions, i.e., a flat head. The rim of the body includes protrusions positioned according to a pattern corresponding to the weld points and the continuous weld. These protrusions can be produced by the molds used during the injection or thermoforming of the material forming the capsule body. In this case, the molds have negative protrusions. Thus, the protrusions are positioned at the locations where the fusible material must be treated to obtain the weld points and the continuous weld according to the invention when the welding head is applied to the lid, which is itself placed on the rim. The welding head comes into direct contact with the lid, which is compressed between the protrusions and the welding head; thus, the heat transfer (or ultrasonic transfer) is concentrated at the level of these protrusions, enabling the weld points and the continuous weld to be formed..

[0083] Other features, variations and advantages of the implementation of the invention will become clearer from the description and examples that follow, given by way of illustration and not limitation of the invention.

[0084] The invention further relates to a welding head adapted for welding a lid onto a capsule body in order to obtain a capsule according to the invention, in which the projections correspond to the welding points and the continuous weld. BRIEF DESCRIPTION OF THE FIGURES

[0085] [Fig.l] is a schematic cross-sectional view of two capsule body shapes implemented according to the invention.

[0086] [Fig.2] is a schematic cross-sectional view of a capsule implemented according to the invention.

[0087] [Fig.3] is a schematic view along section AA of capsule 1 shown in [Fig.2],

[0088] [Fig.4] are partial schematic views along the same section AA of alternative embodiments.

[0089] [Fig.5] is a schematic view of a welding head for welding the lids onto the capsule bodies according to the invention.

[0090] [Fig.6] is a schematic view of a capsule body according to the invention.

[0091] [Fig.7] is a diagram representing a method for manufacturing a capsule according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0092] Figure 1 is a schematic cross-sectional view of two different shapes of capsule bodies 2. These capsule bodies 2 form enclosures into which the contents of the capsule can be placed before closing it. According to the embodiment of the frustoconical capsules, the body consists of a base 3 of substantially circular shape and a side wall 4 with a circular rim 5. According to the embodiment of the hemispherical capsules, the body consists of a shell 6 in the shape of a hemisphere also with a circular rim 5.

[0093] Figure 2 is a schematic cross-sectional view of two different capsule shapes 1. These are capsules 1 comprising the bodies described in Figure 1. These capsules 1 comprise, in addition to the bodies, a lid 7. The capsule according to the invention further comprises a substance in powder or liquid form for the preparation of a beverage (introduced before closing the capsule with the lid) which has not been shown in Figure 2.

[0094] As previously stated, the lid 7 is composed of a multi-layered laminate. In the described embodiments, the lid comprises:

[0095] - an inner layer, positioned on the rim side, comprising fusible material, for example a layer of non-woven material with a fusible resin;

[0096] - a barrier layer, positioned in the middle of the laminate, giving the lid its sealing; then

[0097] - a filter layer adapted to retain elements of the contents that should not to prevent any particles, such as ground coffee beans, from escaping the capsule during beverage preparation. This layer is positioned on the outside (opposite side to the rim surface).

[0098] Alternatively, the inner layer can also be a moisture and airtight layer and thus act as a barrier layer, so there is no need to provide an additional barrier layer.

[0099] Alternatively, the inner layer can also be a layer for retaining elements of the contents which must not escape from the capsule during the manufacture of the beverage, it is then not necessary to provide an additional filtration layer.

[0100] The layers of the laminate are bonded together using a binder.

[0101] The fusible material may be biodegradable and / or compostable materials, for example PLA (polylactic acid), PHA (polyhydroxyalkanoates), PHB (poly-[3-hydroxybutyrate], polyhydroxybutyrate), PBS (polybutylensuccinate), PBAIT (polybutylene-co-aliphate-co-terephthalate), PBAT (polybutylenadipate-terephthalate), or a hot melt adhesive. Or a cellulose fiber layer additively containing one or more of these materials.

[0102] The layers of the laminate may be made of biodegradable and / or compostable materials, for example, paper, non-woven fabrics, cellulose, SiOx layers, biopolymers such as PLA (polylactic acid), PHA (polyhydroxyalkanoates), PHB (poly-[3-hydroxybutyrate, polyhydroxybutyrate), PBS (polybutylensuccinate), PBAIT (polybutylene-co aliphate co-terephthalate), PBAT (polybutylenadipate-terephthalate), or a hot melt adhesive.

[0103] The material forming the body of the capsule 2 can be in biodegradable and / or compostable materials for example PLA (polylactic acid), PHA (polyhydroxyalkanoates), PHB (Poly-[3-hydroxybutyrate, polyhydroxybutyrate), PBS (polybutylensuccinate), PBAIT (polybutylene-co aliphate co-terephthalate), PBAT (polybutylenadipate-terephthalate).

[0104] Fig. 3 is a schematic view along section AA of the capsule 1 shown in Fig. 2. Section AA is made between the body 2 of the capsule 1 and the operculum 7 welded to the rim 5. At the center is the opening 8 of the enclosure or cavity formed by the body 2. The ring surrounding the opening 8 represents the surface of the rim 5. This surface is divided into three portions: an inner portion extending from the boundary 9 between the opening and the rim to the first dashed circle 9; an inner sub-portion extending between the first dashed circle 10 and the second dotted circle 11 and an outer sub-portion extending between the second dotted circle 11 and the outer limit 12 of the rim 5. The inner sub-portion and the outer sub-portion are sub-portions of the outer portion extending between the first dotted circle 10 and the outer limit 12 of the rim 5. These portions are not physically delimited on the rim, they form theoretical zones.

[0105] Weld points 13 are present on the inner portion. Weld points 14 are also present on the outer sub-portion. The continuous weld 15 is present in the inner sub-portion. The continuous weld 15 is represented here as a circular line; however, it can take any shape as long as it is circumscribed between the first dashed circle 10 and the second dashed circle 11. Furthermore, the continuous weld 15 encircles the opening in a closed fashion to make the weld of the cover watertight. The continuous weld 15 can have other shapes; for example, the continuous weld 15 can locally have the shape of a sinusoid or a zigzag that encircles the opening. The weld points 13 and 14 are round weld points, but other shapes can be used as described in [Fig. 4].

[0106] The distance between two weld points 13 is greater than a threshold pb, so the distance d is greater than the threshold pi. Similarly, the distance d' between a weld point 13 and the continuous weld 15 is also greater than the threshold ph. Thus, the distances det d's are greater than the threshold pb. Therefore, the weld points 13 are sufficiently far from each other and from the continuous weld 15 to avoid any accumulation of thermal energy, which could damage the foil, some layers of which, and the binder, may be thermally sensitive.

[0107] Furthermore, to enable the weld points 13 to support the stresses that the continuous weld 15 would otherwise undergo, the density of weld points 13 can be selected so that for every point p 16 of the inner portion there is at least one weld point 13 at a distance less than a threshold p2 from point p 16. For example, point p 16 is at a distance d'' less than p2 from weld point p 16.

[0108] The distance between two weld points 14 is greater than a threshold p3, so the distance d(3) is greater than the threshold p3. Similarly, the distance d(4) between a weld point 14 and the continuous weld 15 is also greater than the threshold p3. Thus, the distances d(3) and d(4) are greater than the threshold p3. Therefore, the weld points 14 are sufficiently far from each other and from the continuous weld 15 to prevent any accumulation of thermal energy, which could damage the foil, some layers of which, and the binder, may be thermally sensitive.

[0109] The distances d and d(3) are the shortest distances between the two weld points concerned. Similarly, the distances d' and d(4) are the shortest distances between the weld points and the continuous weld concerned.

[0110] The width of the inner sub-portion determines the maximum width of the continuous weld 15. The width of the continuous weld 15 is between 0.3 mm and 1.5 mm, preferably between 0.3 mm and 0.75 mm. The width of the continuous weld represents between 10% and 50% of the rim width and preferably between 10% and 25% of the rim width.

[0111] The threshold pi is greater than 0.4 mm and preferably greater than 0.5 mm.

[0112] The p2 threshold is less than 1 mm and preferably less than 0.5 mm.

[0113] The p3 threshold is greater than 0.4 mm and preferably greater than 0.5 mm.

[0114] Figure 4 shows partial schematic views along the same section AA of alternative embodiments of capsules 1 according to the invention. The description in [Fig. 3] applies to each of these embodiments.

[0115] The embodiment of the rim 5.1 describes weld points 14.1 and 13.1 which are rectangular in shape. The rectangular weld points are oriented tangentially to the circle 9.1 formed by the opening. The same conditions on the distances between the weld points and the continuous weld as those described in [Fig. 3] also apply to these rectangular weld points.

[0116] The embodiment of the flange 5.2 describes weld points 14.2 and 13.2 which are square in shape. The same conditions on the distances between the weld points and the continuous weld as those described in [Fig. 3] also apply to these square weld points.

[0117] The embodiment of the rim 5.3 describes weld points 14.3 and 13.3 which are rectangular in shape. The rectangular weld points are oriented radially with respect to the circle 9.3 formed by the opening. The same conditions on the distances between the weld points and the continuous weld as those described in [Fig. 3] also apply to these rectangular weld points.

[0118] The invention is not limited to the shapes of the weld points (13, 13.1, 13.2, 13.3, 14, 14.1, 14.2, 14.3) and to the shape of the continuous weld 15 described in Figures 3 and 4. Polygonal shapes, arcs of circles or even oval shapes can be implemented as shapes for the weld points.

[0119] Fig. 5 is a schematic view of a welding head 18 for welding the lids 7 onto the bodies 2 of the capsules 1 according to the invention.

[0120] The welding head 18 is fixed to a device (not described) for heating the welding head 18 to a temperature sufficient to allow the fusible material of the seal to melt when the welding head 18 is in contact with the seal. Alternatively, the welding head 18 may be fixed to a device (not described) that emits ultrasound into the welding head 18, which is transmitted to the seal 15 to allow the fusible material of the seal 15 to melt when the welding head 18 is in contact with the seal.

[0121] The seal 7 is placed on the rim 5, 5.1, 5.2, 5.3 so as to close the cavity formed by the body 2 of the capsule 1. The sealing head 18 is pressed onto the seal 7. A transfer of heat or ultrasound then occurs from the sealing head 18 to the seal 7. Since the sealing head 18 is provided with projections 19, 20, 21 that are in closer contact with the seal than the rest of the sealing head 18, this heat or ultrasound transfer occurs mainly via these projections. The central part of the sealing head 18 is hollowed out 22 to reduce heat or ultrasound transfer to undesired areas. The projections 19, 20, 21 are protuberances which advance towards the operculum in contrast to the hollowed part 22 of the weld head which is recessed.The welding operation performed with such a welding head 18 thus melts the fusible material (by heat transfer or ultrasound) present in the lid 7 at the protrusions, while minimally melting the remaining fusible material contained in the lid 7. A welding pattern is then obtained, producing the weld points (13, 13.1, 13.2, 13.3, 14, 14.1, 14.2, 14.3) and the continuous weld 15 as described in the embodiments shown in Figures 3 and 4, provided that the shape of the protrusions 20 and 21 corresponding to the weld points is modified. Once the welding operation is completed, the lid 7 is held on the rim 15, 15.1, 15.2, 15.3.

[0122] The [Fig.6] is a schematic view of a capsule body 2 according to an embodiment of the invention.

[0123] It is also possible to obtain capsules 1 with welding schemes of the lid 7 corresponding to the embodiments described in figures 3 and 4 by using a welding head (not shown here) without the projections 19, 20, 21 and by providing projections 24, 25, 26 on the rim 5 of the body 2 of the capsule 1. These projections 24, 25, 26 make it possible to increase the pressure between the lid 7 and the welding head without projections 19, 20, 21, allowing a thermal transfer or an ultrasonic transfer mainly at the level of the projections 24, 25, 26.

[0124] Fig. 7 is a diagram representing a method for manufacturing a capsule according to the invention.

[0125] In a first step, IF the body 2 of the capsule 1 is manufactured either by molding, for example by injection of the material forming the body 2, or by thermoforming, by example by suction or compression of a heated plate against a mold in the shape of the capsule body.

[0126] In the case where a welding head 18 without projections 19, 20, 21 is used (Sa=l), the mold provides for the manufacture of the body 2 according to [Fig.6], that is to say a body 2 having the projections 24, 25, 26 on its rim 5.

[0127] Otherwise (Sa =0), the mold can provide a body 2 having a flat rim 5.

[0128] In all cases, it is possible to provide a surface roughness on the edge in order to that welds 13, 14, 15 adhere better to body 2 of the capsule.

[0129] At step S2, the cavity formed by the body 2 is filled with contents to prepare the drink.

[0130] In step S3, the operculum 7 is placed on the body 2 to close the cavity. The operculum covers the rim 5 of the body 2. The welding head compresses the operculum against the body 2. The heated welding head or the ultrasonic welding head then performs the weld points (13, 13.1, 13.2, 13.3, 14, 14.1, 14.2, 14.3) and the continuous weld 15.

[0131] If the body 2 has projections (Sa=l), the welding head used is flat, i.e., it does not have the projections described in [Fig. 5]. If the body 2 does not have projections (Sa=0), the welding head used has projections as described in [Fig. 5].

Claims

Demands

1. A capsule for preparing a beverage, said capsule comprising: a body forming a cavity with an opening surrounded by a rim, said cavity being adapted to receive contents for preparing the beverage, the rim comprising an inner portion and an outer portion, and a seal welded to the rim by means of: - a continuous weld on the outer portion of the rim, the continuous weld surrounding the opening; - weld points on the inner portion of the rim, each weld point being spaced at a minimum distance greater than a predetermined threshold: • from other weld points of the inner portion; • from the continuous weld; wherein the outer portion comprises an inner sub-portion and an outer sub-portion and wherein the continuous weld is on the inner sub-portion;and in which the seal on the rim is also sealed by means of weld points on the outer sub-portion, each weld point of the outer sub-portion being spaced at a minimum distance greater than a third predetermined threshold: - from the other weld points of the outer sub-portion; - from the continuous weld.;

2. Capsule according to claim 1, wherein for each point p of the inner portion of the rim there is a weld point of the inner portion spaced with point p by a minimum distance less than a second predetermined threshold.

3. Capsule according to any one of the preceding claims wherein the weld points are one or a combination of the following shapes: - circular; - polygonal; - rectangular, with rectangular points arranged perpendicular to the rim; - rectangular, with rectangular points arranged tangentially to the rim; - in arcs of a circle; - square.

4. Capsule according to any one of the preceding claims wherein at least a portion of a rim surface has a roughness greater than a predetermined value Ra.

5. Capsule according to any one of the preceding claims wherein the lid is a laminate comprising: - an inner layer comprising fusible material; and - at least one other layer; - the inner layer being disposed between the body comprising the rim and at least one other layer.

6. Capsule according to claim 5, wherein at least one layer comprises: - a barrier layer; and / or - a filtration layer.

7. Capsule according to any one of claims 5 and 6 in which the adjacent layers of the laminate are agglomerated with a binder.

8. Capsule according to any one of the preceding claims wherein the body and / or the lid are made up of at least 85% by weight of biodegradable and / or compostable and / or methanizable materials.

9. A method for manufacturing a capsule according to any one of claims 1 to 8, comprising the following steps: - filling the cavity with the contents to prepare the beverage, - applying a sealing head to the lid to close the cavity and form the capsule, - wherein the sealing head comprises projections corresponding to the welding points and the continuous weld.

10. A method for manufacturing a capsule according to any one of claims 1 to 8, comprising the following steps: - manufacturing the body of the capsule to obtain on the rim projections corresponding to the welding points and the continuous weld, - filling the cavity with the contents to prepare the drink, - applying a welding head to the lid to close the cavity and form the capsule.

11. A manufacturing method according to any one of claims 9 and 10 wherein the welding is done by applying heat or ultrasound to the lid via the welding head.

12. Welding head adapted for welding a lid onto a capsule body to obtain a capsule according to any one of claims 1 to 8, wherein the welding head comprises projections corresponding to the weld points and the continuous weld.

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