Capsule intended for receiving a substance for preparing a beverage, and production method

Abstract

The invention relates to a capsule (1) for receiving a substance for preparing a beverage, said capsule comprising a body having a side wall (2) bordered on either side by a base (3) and by a rim (4) surrounding an opening (5) in said body, the body being formed by dry-moulding a sheet of cellulose pulp.

Description

[0001] CAPSULE INTENDED TO RECEIVE A SUBSTANCE FOR THE PREPARATION OF A BEVERAGE AND MANUFACTURING METHOD

[0002] The invention relates to a capsule intended to receive a substance for the preparation of a beverage, as well as a manufacturing method by dry molding of the body of such a capsule.

[0003] Capsules are known whose body has a side wall bordered on either side by a base and by a rim surrounding an opening in said body, the substance for preparing a drink being introduced into said capsule through said opening, then enclosed inside said capsule by association, for example by gluing, of a cover on the rim to conceal the opening.

[0004] Such capsules are intended in particular for the preparation of a hot drink such as coffee, tea or infusion. To do this, a capsule is installed in the housing of a machine provided for this purpose, where it is held by a piston while an extracting liquid, for example hot water, passes through it and the substance it contains.

[0005] The capsule must be opened to allow the flow of the beverage through it, but the substance must be preserved in the capsule with good barrier properties against oxygen and air humidity in order to preserve its organoleptic properties.

[0006] To achieve this, capsules are known whose body is formed by stamping a sheet of metal material, particularly aluminum. Such capsules have good air and moisture-proof properties, but are expensive to produce and difficult to recycle.

[0007] Also known, for example from documents WO-2019 / 185637 and WO-2022 / 112615, are capsules whose body is formed by injection molding of a compostable plastic material, these capsules further comprising a sealing film which is associated with at least one of the bottom, the side wall or the upper opening of said body, in particular during its molding according to an IML (In-Mould Labeling) process, said film being compostable and having barrier properties to oxygen and / or moisture.

[0008] These capsules have an improved ecological impact, in that they are biodegradable and compostable, both industrially and domestically, and also guarantee good organoleptic conservation of the substance they contain.

[0009] However, in practice these capsules prove to be expensive and complex to produce.

[0010] The invention aims to improve the prior art by proposing a capsule combining good oxygen and moisture barrier properties while having a limited ecological impact, in particular by being biodegradable and / or compostable, while being easy and inexpensive to produce.

[0011] To this end, according to a first aspect, the invention provides a capsule intended to receive a substance for the preparation of a beverage, said capsule comprising a body having a side wall bordered on either side by a bottom and by a rim surrounding an opening in said body, the body being formed by dry molding of a sheet of cellulose pulp.

[0012] According to a second aspect, the invention proposes a method of manufacturing by dry molding the body of such a capsule, which provides for:

[0013] - form a sheet of cellulose pulp;

[0014] - thermoform the capsule by hot molding the said sheet.

[0015] Other features and advantages of the invention will appear in the following description, given with reference to the appended figures, in which:

[0016] - Figure 1 represents in exploded perspective a capsule according to one embodiment of the invention; - Figures 2 and 3 each represent in exploded perspective, respectively seen from below (Figure 2) and seen from above (Figure 3), a capsule according to another embodiment of the invention respectively;

[0017] - Figure 4 is a representation of a cross geometry formed around the area of ​​the cellulose pulp web to be molded.

[0018] In relation to these figures, a capsule 1 is described below for receiving a substance for the preparation of a beverage.

[0019] The capsule 1 comprises a body having a side wall 2 bordered on either side by a bottom 3 and by a rim 4 surrounding an opening 5 of said body.

[0020] The body is formed by molding a cellulose pulp, and preferably contains exclusively cellulose, in particular 100% from sustainable and / or organic agriculture.

[0021] Thus, an easily recyclable capsule 1 can be manufactured inexpensively and with high yield, with reduced carbon dioxide emissions, particularly compared to injection molding of a plastic material.

[0022] Furthermore, the exclusive use of cellulose makes it possible to obtain a capsule 1 whose body can be easily composted, both industrially and domestically, in particular with a reduced composting time (of the order of one month) compared to the average composting time of capsules made from compostable molded plastic (around 6 months).

[0023] In particular, capsule 1 is biodegradable and / or compostable according to standard EN 13432.

[0024] The body of the capsule 1 is formed by dry molding of a sheet 20 of cellulose pulp, which makes it possible to considerably increase the manufacturing yield of the capsule while limiting the number, size and cost of the necessary installations, as well as water and energy costs.

[0025] In particular, the use of such a manufacturing process makes it possible to obtain a production yield of capsules 1 of the order of 1000 capsules per minute, for an annual production volume greater than one billion capsules 1 .

[0026] The dry molding manufacturing process of the capsule body 1 provides for:

[0027] - form a sheet 20 of cellulose pulp;

[0028] - thermoform the capsule 1 by hot molding said sheet.

[0029] According to one embodiment, the method for manufacturing the body of the capsule 1 provides, prior to thermoforming, for injecting air into the sheet 20 of cellulose pulp. In particular, the method may provide for:

[0030] - separating cellulose fibers from a cellulose source, in particular by grinding a natural source of cellulose, such as wood pulp, cotton, flax, hemp, or sugar cane, or from a recycling source, such as paper, cardboard or textiles;

[0031] - collecting the cellulose fibers thus separated on a conveyor belt, in particular by injecting air into them upstream of their grinding, using a process called "air laid", so as to form on said conveyor belt a fluffy, thick and dense layer, with a weight of between 300 and 15,000 g / m 2 ;

[0032] - compacting said fluffy layer, in particular by passing it between two roller compressors, possibly heated, so as to obtain a sheet 20 of cellulose pulp of controlled thickness, in particular between 500 and 700 μm;

[0033] - preheat said tablecloth, in particular to a temperature between 150 and 170°C;

[0034] - compressing said sheet thus preheated in a mold of suitable shape, in particular by means of a hydraulic press, with a pressure of the order of 45 MPa, in order to obtain by thermoforming capsule bodies 1 from said compressed sheet.

[0035] According to another embodiment, the method for manufacturing the body of the capsule 1 provides for forming the sheet 20 in the form of a sheet of cellulose pulp, having in particular a thickness of between 0.5 and 1 mm, for example of the order of 0.75 mm. In particular, the sheet may be based on cellulose pulp of the NBSK type (Northern Bleached Softwood Kraft).

[0036] Advantageously, the sheet may be wetted, for example by spraying water on the surface, prior to thermoforming to improve its moldability while allowing the water to evaporate during thermoforming.

[0037] According to one embodiment, the geometry of the sheet 20 can be modified, in particular by cutting, to improve the thermoforming of the capsule 1. Figure 4 represents a cross geometry formed around the central part 20a of the area of ​​the sheet 20 to be molded, this geometry being arranged to improve the stretching capacity of said sheet in the molding cavity in order to secure the formation of the capsule 1, in particular relative to its thickness.

[0038] According to one embodiment, the sheet 20, in particular when it is in the form of a sheet of cellulose pulp, can be preformed prior to thermoforming in order to promote the shaping of the capsule 1 in the hot mold. In particular, in particular for a cross geometry, the sheet 20 can be preformed in the shape of a cone, for example extending around the center 20a with the branches of the cross folded back.

[0039] The cellulose pulp used makes it possible to obtain the food compatibility which is necessary for packaging a substance for preparing a beverage in the capsule 1, in particular by eliminating the need to add an internal coating compatible with food. In particular, the cellulose pulp used is free from substances harmful to health and / or the environment, which could contaminate the substance for preparing the beverage by contact with the body of the capsule 1.

[0040] Advantageously, the cellulose pulp forming the body of the capsule 1 comprises microfibrillated cellulose (MFC), in particular between 1% and 50% by weight of MFC microfibrillated cellulose.

[0041] Microfibrillated cellulose (MFC) consists of individual cellulose microfibrils or aggregates. These microfibrils are typically 2 to 20 nanometers in diameter and a few micrometers long. Microfibril aggregates are composed of several cellulose microfibrils agglomerated together.

[0042] The production of microfibrillated cellulose (MFC) is based on the release of the constituent elements of the secondary wall of lignocellulosic fibers by mechanical means coupled with pretreatments, enzymatic or chemical. The fibers used can be unbleached or bleached chemical pulps, mechanical pulps produced from wood, recycled pulps, etc.

[0043] In relation to figures 1 to 3, the body of the capsule 1 has a geometry of revolution around a central axis forming a side wall 2 which is generally inscribed in a truncated cone with a right generatrix between the bottom 3 and the upper rim 4.

[0044] The capsule 1 is equipped with an upper cover 16 which is associated with the rim 4 to cover the opening 5, forming in said body a compartment for loading the substance.

[0045] In the embodiments shown, the opening 5 may allow the substance to be loaded into the compartment which is closed opposite by the bottom 3, said opening then being closed by the upper cover 16 after said loading. In Figure 1, the bottom 3 comprises a lower opening 6 intended to be covered by a lower cover 17. In particular, the lower opening 6 may be first hidden by the cover 17, in order to load the substance into the compartment through the upper opening 5, which is then closed by the cover 16.

[0046] Alternatively, the capsule 1 shown in Figure 1 can be loaded through the bottom 3. In this case, the upper opening 5 is first hidden by the cover 16, then the capsule 1 is turned over to be able to load the substance through the lower opening 6, the lower cover 17 then being associated with said capsule to close said compartment before preparing the drink.

[0047] The capsule 1 is intended in particular for the preparation of a hot drink such as coffee, tea or infusion. To do this, the capsule 1 can be placed in the housing of a machine provided for this purpose, in order to be crossed by at least one pin to inject extracting liquid, in particular hot water, into the substance contained in the capsule 1.

[0048] The injection of the liquid induces an increase in the pressure in the compartment to allow, after rupture of a frangible wall of the capsule 1, the flow of the drink out of said capsule.

[0049] During the preparation of the beverage, the capsule 1 is subjected to an injection of water at a temperature of between 86°C and 90°C and under a pressure of up to 20 bars, for a duration of approximately 2 minutes. In particular, to prepare a coffee-type beverage, the quantity of water injected into the capsule 1 is between 40 mL and 150 mL.

[0050] The capsule 1 shown in Figures 1 and 3 is adapted to be placed in a machine in which it is held by a piston provided with pins to pierce its base 3 or its lower seal 17. In addition, the base 3 or the lower seal 17 is crossed by at least one pin to inject extractor liquid into the substance contained in the capsule 1, which induces an increase in pressure in the compartment to allow, after rupture of the upper seal 16, the flow of the beverage through the opening 5.

[0051] According to the embodiment of figure 1, the lower cover 17 can be arranged to be easily passed through by the pins to be injected, in particular more easily than the cellulose base 3 of the capsule 1, in order to limit the risks of deformation of said capsule during its use.

[0052] In Figure 2, the bottom 3 has a central orifice 19 which opens into the compartment for packaging the substance, as well as an upper wall which extends substantially radially in said compartment, and on which a network of raised spikes is formed, a perforable membrane being arranged in said compartment between the substance and the raised spikes.

[0053] Thus, when the capsule 1 is placed in a machine to prepare a beverage, the upper cover 16 is crossed by at least one pin to inject extractor liquid into the compartment, which causes an increase in pressure, under the effect of which the membrane tears on the raised studs of the bottom 3, in order to allow the flow of the beverage through the central orifice 19.

[0054] In order to preserve the organoleptic characteristics of the substance stored before its use to prepare a beverage, the capsule 1 must be airtight, in particular by forming a barrier against the circulation of oxygen and humidity, both towards the inside of said capsule, to prevent the substance it contains from being altered by the ambient air and humidity, and towards the outside, in particular to prevent the drying out of a substance packaged in a moist and / or greasy form.

[0055] In particular, to ensure optimal preservation of the substance, capsule 1 has the following characteristics: - an oxygen transmission rate of less than 10 cm 3 / m 2 .day.atm, in particular of at most 5 cm 3 / m 2 .day.atm, and more particularly less than 1 cm 3 / m 2 .day.atm, measured according to ASTM D3985;

[0056] - a water vapor transmission rate of less than 60 g / m 2 .24h, and more particularly less than 10 g / m 2 .24h, measured according to ASTM E96 standard in tropical conditions (38°C and 90% humidity).

[0057] With such characteristics, capsule 1 can notably be stored:

[0058] - before filling with a substance for preparing a beverage: at a temperature between 15 and 25°C, and up to 50°C for a maximum period of 6 weeks during transport;

[0059] - after filling: in a dry and temperate place, with a maximum ambient humidity level between 35 and 55%.

[0060] Advantageously, the body of the capsule 1 is subjected to a preliminary treatment to close the pores of the cellulose sheet 20 constituting it, in order to form a first barrier against oxygen and water vapor.

[0061] Furthermore, the use of a cellulose pulp comprising microfibrillated cellulose MFC contributes favorably to the sealing of the capsule against oxygen and water vapor.

[0062] However, to the extent that the material constituting the body of the capsule 1 does not have sufficient performance, in particular due to the porosity of the cellulose, the side wall 2 can be covered with a sealing label 18 and / or a sealing coating forming a second barrier against oxygen and humidity.

[0063] The coating and / or the sealing label 18 may be applied to the side wall 2, not only to reinforce its barrier properties to oxygen and water vapor, but also to provide it with additional barrier properties, in particular lipophobic properties, in order to further preserve the organoleptic properties of the substance packaged in said capsule, but also to prevent the impregnation of the body of the capsule 1 by the substance for preparing the beverage, when the latter is in the form of a wet and / or greasy paste.

[0064] In the embodiments shown, the lids 16, 17 ensure a watertight closure of the capsule 1, in particular by forming a barrier against oxygen and humidity.

[0065] The upper seal 16 and the possible lower seal 17 are in particular fixed to the body of the capsule 1 by heat sealing, by applying for approximately 350 ms a pressure between 3 and 6 bars at a temperature between 190°C and 260°C.

[0066] In the embodiments shown, the side wall 2 is covered with a sealing label 18 which is formed from a sealing film 12, the lower cover 17 being able to be made with the same film and the upper cover 16 in a film 12 according to document WO-2022 / 112613.

[0067] The sealing label 18 can be associated with the side wall 2 during or after the molding of the body of the capsule 1, according to an IML (In-Molding Process) process, during which said label is placed against a side wall of a molding cavity of said body before actual production of said molding, so as to simultaneously carry out the steps of forming said body and associating said label with its side wall 2. As a variant, the label can be associated by thermoforming.

[0068] The sealing label 18, and more generally the film 12 constituting said label and the cover(s) 16, 17, may also comprise cellulose, in particular comprising microfibrillated cellulose MFC.

[0069] In particular, the sealing film 12 comprises at least one layer based on microfibrillated cellulose MFC. Advantageously, the MFC layer may be in the form of a layer of paper formed with microfibrillated cellulose so as to be highly fibrillated, and may in particular be translucent, so as to be able to be a particularly barrier to oxygen.

[0070] Furthermore, the use of a cellulose pulp comprising microfibrillated cellulose MFC contributes favorably to the association of the label 18 on the side wall 2, in particular by limiting the granulosity of said wall.

[0071] For aesthetic and / or commercial reasons, in particular in relation to the production of the label 18, the MFC layer may be provided with a print produced by depositing ink on one of its faces, said print comprising for example textual information and / or a decorative element, such as for example a logo, a brand, and / or a description of the substance contained in the capsule 1.

[0072] In particular, since the MFC layer is transparent, the printing ink can be deposited on its inner face in order to be protected. In addition, to improve the aesthetic qualities of the capsule 1, the printing can have gloss and / or antistatic properties.

[0073] According to exemplary embodiments, the MFC layer has:

[0074] - a thickness between 30 and 70 pm; and / or

[0075] - a surface mass between 40 and 90 g / m 2 .

[0076] The MFC layer makes it possible in particular to obtain a sealing film 12 having a high surface mass and sufficient oxygen tightness for the barrier function, while being perfectly biodegradable and / or compostable.

[0077] The sealing label 18 may have been treated to improve its resistance to humidity, for example by means of the sealing coating, applied in the form of a lacquer or by metallization on said label. Alternatively, the sealing coating is applied directly to the side wall 2 of the capsule 1. Furthermore, the sealing coating may also be applied to at least one of the lids 16, 17.

[0078] Advantageously, the sealing coating, like the sealing film 12, is biodegradable and / or compostable, in order to improve the total environmental impact of the capsule 1, in particular by avoiding the consumer having to separate the label 18 and the seal(s) 16, 17 from the body of the capsule 1 before its composting.

[0079] According to one embodiment, the waterproofing coating may comprise microfibrillated cellulose MFC, for example derived from food plants, in particular root vegetables such as beetroot. Such a composition is the subject of document EP-3 145 958.

[0080] The waterproofing coating may be based on an aqueous dispersion of microfibrillated cellulose MFC, comprising in particular between 0.5% and 20% by weight of microfibrillated cellulose MFC, in particular less than 5% by weight.

[0081] According to one embodiment, the waterproofing coating is made from an anionic dispersion of microfibrillated cellulose MFC, and has in particular the following characteristics:

[0082] - a solid particle content of around 32% by weight;

[0083] - a pH that is substantially neutral or slightly basic, in the order of 7 to 8;

[0084] - a viscosity between 300 and 500 mPa.s;

[0085] - a density of the order of 1.02 at 20°C.

[0086] Such an anionic dispersion has excellent barrier properties to oxygen and moisture, as well as excellent impermeability to grease and oil, and can be set by heat on its application support, in particular the side wall 2 of the capsule 1 and / or the label 18 coating it, to form a sealing barrier as desired. In particular, the sealing coating can be applied by dipping, by spraying or by transfer, before being optionally exposed to a heat source of suitable temperature to form a sealing coating thereon. Advantageously, the surface mass of the sealing coating is between 2 and 12 g / m 2 .

[0087] Furthermore, the sealing film 12, in particular the label 18, may comprise a sealing layer on the body of the capsule 1, in particular on its side wall 2, said sealing layer being able to be adapted to hot and / or cold sealing.

[0088] According to one embodiment, the sealing coating forms a metallization layer, for example based on aluminum. In particular, this layer can be applied by transfer or by spraying, having a thickness of less than 10 μm, in particular less than 1 μm.

Claims

CLAIMS 1. Capsule (1) intended to receive a substance for the preparation of a beverage, said capsule comprising a body having a side wall (2) bordered on either side by a bottom (3) and by a rim (4) surrounding an opening (5) of said body, said capsule being characterized in that the body is formed by dry molding of a sheet (20) of cellulose pulp.

2. Capsule (1) according to claim 1, characterized in that the cellulose pulp comprises microfibrillated cellulose MFC.

3. Capsule (1) according to claim 2, characterized in that the cellulose pulp comprises between 1% and 50% by weight of microfibrillated cellulose MFC.

4. Capsule (1) according to any one of claims 1 to 3, characterized in that it has an oxygen transmission rate of less than 10 cm 3 / m 2 .jour.atm, according to ASTM D3985.

5. Capsule (1) according to claim 4, characterized in that the oxygen transmission rate is at most 5 cm 3 / m 2 .day.atm, and in particular less than 1 cm 3 / m 2 .jour.atm, according to ASTM D3985.

6. Capsule (1) according to any one of claims 1 to 5, characterized in that it has a water vapor transmission rate which is less than 60 g / m 2 .24h, measured according to ASTM E96.

7. Capsule (1) according to claim 6, characterized in that the water vapor transmission rate is less than 10 g / m 2 .24h, measured according to ASTM E96.

8. Capsule (1) according to any one of claims 1 to 7, characterized in that the side wall (2) is covered with a sealing label (18) and / or a sealing coating.

9. Capsule (1) according to claim 8, characterized in that the label (8) and / or the sealing coating comprises microfibrillated cellulose MFC.

10. Capsule (1) according to any one of claims 1 to 9, characterized in that it is biodegradable and / or compostable.

11. Method of manufacturing by dry molding the body of a capsule (1) according to any one of claims 1 to 10, said method provides for: - form a sheet (20) of cellulose pulp; - thermoform the capsule (1) by hot molding said sheet.

12. Manufacturing method according to claim 11, characterized in that it provides, prior to thermoforming, for injecting air into the sheet (20) of cellulose pulp.

13. Manufacturing method according to claim 11, characterized in that it provides for forming the sheet (20) in the form of a sheet of cellulose pulp.

14. Manufacturing method according to claim 13, characterized in that it provides for wetting the sheet before its thermoforming.

15. Manufacturing method according to any one of claims 11 to 14, characterized in that it provides for cutting of the sheet (20) to form a cross geometry around the area (20a) of said sheet to be molded.

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