A FLEXIBLE CONTAINER FOR THE PREPARATION OF FOOD OR BEVERAGES THAT HAS A RIGID PART.

Abstract

The present invention relates to a flexible or semi-flexible closed container (1) for holding an ingredient for preparing an edible product in a food or beverage preparation machine, said container comprising: (i) flexible or semi-flexible side walls (2) forming a flattened container body, and (ii) a cup-shaped lower portion (3) adapted for insertion of a fluid injection element of the machine, the container (1) being formed from an elongated primary flat preform sheet (5) made of a single piece of flexible material, which is folded into a U-shape about its transverse axis of symmetry (Lx), and sealed along its lateral (4) and upper (34) edges, wherein said cup-shaped lower portion (3) is a hollow volume having a concave lower side (7) and convex side sides (8), and the profile curvature of said lower side (7) is identical to the profile curvature of each of said side sides (8).

Description

A flexible container for preparing food or beverages that has a rigid part FIELD OF INVENTION The present invention relates to a closed flexible sachet, said sachet containing a beverage ingredient and adapted for use in a beverage preparation machine by piercing a wall of the sachet and injecting a liquid into it to mix with said ingredient. BACKGROUND OF THE INVENTION The preparation of beverages is known in the art to involve inserting a capsule containing a food or beverage ingredient, such as instant coffee, milk, or chocolate, into a beverage dispensing machine and then injecting water into the capsule to mix with the ingredient. The beverage or soluble food ingredient typically dissolves in water to form the desired final beverage or product, which flows out of the capsule through a suitable outlet. Sometimes, the ingredient may be tea leaves, and the beverage is prepared by infusing the leaves with water placed inside the capsule. As is the case with the aforementioned soluble ingredient, the tea is infused and then dispensed from the capsule through a dispensing outlet. Such capsules are typically rigid or semi-rigid capsules made of plastic or metal (e.g., aluminum). Recently, beverage preparation systems have been developed that utilize flexible packaging instead of capsules. These containers offer several advantages over capsules, such as compactness, faster manufacturing (forming, filling, and sealing operations can be performed in a single line), and improved recyclability. Such flexible containers are described, for example, in patent no. EP 3 414 187 A1 and comprise a flexible wall and a functional insert located at the bottom of the container—sometimes called a nozzle—which is attached to, or otherwise wrapped around, the flexible wall. The insert is a smooth element made of rigid or semi-rigid plastic and includes holes and channels for connecting the bottom of the flexible container to the beverage machine in a fluid-tight manner. In use, once the flexible container is functionally connected to the beverage machine, the machine introduces water into the container through fluid-conducting channels in the insert. This water is then mixed with the ingredient to form a beverage product, which is dispensed from the flexible container through a product dispensing channel in the insert. Essentially, fluid communication between the container and the beverage machine is achieved by connecting a fluid-conducting element of the machine to a flat surface of the container. The flatness of the surface between the ingredient container and the beverage machine ensures a leak-proof seal. Furthermore, the rigidity of the container's flat surface is crucial to prevent deformation during connection with the beverage machine. Typically, the connection is made by piercing or otherwise inserting a machine connection element, such as a needle or similar component, through the container's flat surface. Alternatively, the connection can be made by opening the container wall and pressing a machine nozzle against it to create a fluid-tight seal.If the flat wall of the container is mechanically very weak, it will fold or otherwise deform when the beverage machine's connecting element is pressed against or inserted through it, leading to leakage or even a complete lack of a smooth connection. Furthermore, opening the container with the machine must be easy and reliable; therefore, the force required to open the container wall must be sufficiently low. In some cases, described, for example, in patents EP 3 500 503 A1 or EP 3 500 504 A1, the functional insert comprises several parts that can move relative to each other, such that the insert can be actuated to open or close itself. This allows for complex sequences for water injection, mixing, and product dispensing, sequences tailored to a particular preparation requirement imposed by the type of beverage ingredient to be dissolved. The insert's ability to reseal also provides excellent cleaning of the beverage preparation system. However, such existing flexible packaging has drawbacks. First, the functional insert is made of a material that is not easily recyclable. Furthermore, it is a smooth element and therefore heavy. It is also expensive to manufacture. Other flexible packaging options include reinforced pouches or bags. These are made by folding and sealing a thermoplastic material, which creates a reinforcement on its lower side wall. While such reinforced pouches can form a flat lower side wall suitable for attaching to a beverage machine, manufacturing them requires a complex, multi-folding process to create the reinforced bottom. The multiple folds create overlapping layers of material, which are then sealed. This well-established manufacturing process requires good sealing properties for the material, which can only be achieved with thermoplastic films. If non-thermoplastic films are used, the weaker seal leads to delamination or even unsealed gaps between the folded film layers, which is detrimental to the packaging's mechanical and barrier properties.Again, such reinforced flexible packaging is undesirable because it requires thermoplastic material to form, which is not environmentally harmful. Other types of flexible packaging are known, manufactured through various processes such as folding or perforating a flat, flexible preform material to form three-dimensional volumes. However, these processes frequently lead to the formation of wrinkles on the surface of the packaging during the transformation of the flat, flexible sheet into a three-dimensional volume. Wrinkles are highly undesirable because they result in an inconsistent seal and, consequently, leakage. They also increase the risk of faulty interaction between the packaging and a processing unit, such as a beverage preparation machine, due to the irregular surface of the packaging. Therefore, a primary purpose of the present invention is to provide an improved flexible container for use with a beverage preparation machine, which overcomes the aforementioned drawbacks of existing containers and, in particular, is made of an environmentally friendly material and can be easily attached to a beverage machine in a substantially airtight manner. BRIEF DESCRIPTION OF THE INVENTION The present invention relates to a closed, flexible or semi-flexible container for holding an ingredient for preparing an edible product in a food or beverage preparation machine, by mixing said ingredient with a mixing fluid injected into said container by said machine, said container comprising: (i) flexible or semi-flexible side walls forming a flattened container body, and (ii) a cup-shaped lower portion adapted for insertion of a fluid injection element of the machine, the container being formed from an elongated one-piece primary flat preform sheet made of flexible material, preferably a fiber-based material, which is folded into a U-shape about its transverse axis of symmetry, and sealed along its lateral and upper edges, wherein said cup-shaped lower portion is a hollow volume having a concave lower side and convex side sides, and the profile curvature of said lower side is identical to the profile curvature of each of said side sides. In a particular embodiment of the invention, said lower cup-shaped portion has a hexagonal prism shape, said prism having two opposite vertical edges aligned with the transverse axis of the container, which extend downwards to form downward-extending points, said extended edges having a height such that, for each cross-section of the lower cup-shaped portion measured along the transverse axis of the container, the sum of two heights of the lower cup-shaped portion plus the width of its lower side is constant. Advantageously, this one-piece, elongated, flat primary preform sheet is made of a fiber-based material coated on its inner side with a sealing layer. This fiber-based layer is selected from the following list: paper, cardboard, cabasse-based material, bamboo-based material, starch-based material, cellophane, or a combination thereof. Such materials are considered sustainable packaging materials that are environmentally friendly. The primary flat preform sheet preferably further comprises a barrier coating sandwiched between the fiber-based material and the sealing layer, said barrier coating being a coating against oxygen and / or moisture transfer, and is selected from the list of: metallization coating, silicon oxide (SiOx) coating, aluminum oxide (AlOx) coating, atomic layer deposition (ALD) coating or a combination thereof. In a particularly preferred embodiment of the invention, the container according to the present invention further comprises a secondary thickness reinforcing sheet located at least on the inner surface of the lower cup-shaped portion of said container, said secondary thickness reinforcing sheet being made of fiber-based material coated with a sealing layer, said fiber-based layer being selected from the list of: paper, cardboard, cabasse-based material, bamboo-based or starch-based material, cellophane, or a combination thereof. Advantageously, the packaging of the invention comprises identification means selected from the list of: mechanical codes, optical codes (including color codes and codes printed with non-visible ink), REID labels, one-dimensional barcodes, two-dimensional barcodes, magnetic codes, conductivity codes, detection holes, or any combination thereof. Preferably, the container of the invention further comprises centering transverse holes located on the sealed side edges of said container, said centering holes being adapted for the insertion of centering pins of the beverage preparation machine, to prevent movement of said container in relation to the machine, during beverage preparation. Preferably, the concave lower side of the container comprises a flat portion centered through the transverse and longitudinal axes of the cup-shaped lower portion. It has been found that connecting the fluid injection element, such as, for example, a water injection needle, of the food or beverage preparation machine through a flat surface improves the interface quality between the container and the machine and reduces the need for a complex or bulk fluid injection element to achieve leak-proof fluid communication between the two. For the same reason, this flat surface is preferably oriented in such a way that when the fluid injection element of the machine is inserted into the envelope, the insertion is made along an axis that is orthogonal to the plane of this flat surface. Advantageously, the packaging of the invention is a small envelope or bag. The ingredient contained within the container of the invention may be, for example, a water-soluble powder, or a soluble concentrate in liquid or semi-liquid form, selected from the list of: soups, fruit juices, vegetable juices, broths, coffee, chocolate, tea, dairy components such as milk or cream substitute, smoothies, purees, coulis, creams or a combination thereof, or said ingredient comprises plant leaves adapted to be infused in water. The container formed by the manufacturing process described in this specification comprises generally flexible—or semi-flexible—side walls that allow for excellent beverage product quality through improved dissolution of the contained ingredient with the mixing fluid (typically water) injected into them. At the same time, the interface portion of the container (i.e., its lower portion) with the food or beverage preparation machine to which it is designed to connect is sufficiently rigid to prevent deformation of the container when the machine is smoothly connected. Since its outer walls are manufactured from a single sheet of preform folded in two, it is particularly environmentally friendly (furthermore, its constituent material is preferably chosen from environmentally friendly materials, such as recyclable, biodegradable, industrial compostable, or home compostable materials).The three-dimensional folding of its lower interface provides sufficient rigidity to allow proper opening during use by an external tool (such as, for example, the water injection needle of a food or beverage preparation machine) and, in addition, this three-dimensionally folded lower portion is spared creases that could be detrimental to the proper functioning of said container. BRIEF DESCRIPTION OF THE FIGURES The additional features and advantages of the present invention will become apparent from the description of the currently preferred embodiments, which are described below with reference to the figures, in which: Figure 1 is a side perspective view of a container of the invention; Figure 2 is a top view of a primary flat preform sheet of the invention; Figure 3A is a bottom view of the container in Figure 1; Figure 3B is a side view of the container in Figure 3A; Figure 4 is an enlarged partial perspective top view of a modality of the preform of Figure 2; Figure 5 is a partial bottom perspective view of a container formed with the preform of Figure 4; Figure 6 is a schematic perspective view of a manufacturing machine for making a container of the invention; Figure 7 is a perspective view of a roll of material for manufacturing preform sheets of the invention; Figures 8 and 10 to 14 are schematic side views of a first embodiment of a forming and sealing portion in a machine for making a container of the invention; Figure 9 is a partial enlarged perspective view of a forming plunger for making a container of the invention; Figures 15 to 19 and Figure 21 are schematic side views of an alternative modality of a forming and sealing portion shown in Figures 8 and 10 to 14; Figure 20 is a partial perspective view of the sealing jaws in a forming and sealing machine for making a container of the invention; Figure 22 is a schematic side view of sealing jaws for sealing the side sides of a container of the invention. DETAILED DESCRIPTION OF THE INVENTION The container according to the present invention is adapted for use in a food or beverage preparation machine (not illustrated in the figure). The beverage preparation machine can be of any suitable type but, for example, is a machine as described in patent application no. EP AN 19213419.5. Such machines are well known in the art and comprise a distillation chamber adapted to receive an ingredient container, an injection element adapted to inject a fluid (typically water) into the ingredient container, a fluid supply means (e.g., water) generally comprising a fluid receptacle (or a water connection to a water tap), a fluid pump, a fluid heater, and fluid piping for circulating said fluid from the fluid supply to the distillation chamber, optionally via the heater. In the present invention, the container is adapted to be opened, preferably pierced, by means of a machine's fluid supply system, in particular, by the insertion of a sharp element through a wall of the lower portion of the container, preferably through the underside of said wall. Typically, the machine's fluid injection element is a hollow, needle-shaped element. Dispensing of the prepared food or beverage product into the container by mixing the fluid with the ingredient can be carried out by gravity; however, removal of the finished food or beverage product can also be carried out using the same element that injects the mixing fluid.In the latter case, the injection and dispensing element of the machine comprises at least two channels: one channel fluidly connects the inner compartment of the container to the machine, enabling the machine to inject fluid (e.g., water) into the inner compartment, and a second channel connects the inner compartment of the container to the outer part of the container. The injection means of the machine may also include an additional channel for injecting air into the container during the preparation of food or beverages. Injecting air enhances foam formation during the preparation of specifically aerated products such as dairy-based products (e.g., foamed milk), chocolate-based products (foamed chocolate drinks, chocolate molding foams), or milkshakes. Generally, the packaging has any possible shape compatible with forming a flexible sheet in two (U-shaped formation), such as a bag or sachet, a pad, or any other container that has a generally flattened configuration. Different package sizes can be used in the same machine adapted to hold different quantities of ingredients. The package size (i.e., its height and / or width) does not limit the type of machine that can be used to dispense the ingredient it contains. The package size is adapted to the volume of beverage to be produced; for example, Americanos or soups require large packages, while smaller sachets are used to produce small cups such as espressos. Medium-sized sachets are used to produce frothed milk for cappuccinos. The external design of the bottom of the sachet—the part of the container dedicated to the functional connection of fluids with the beverage machine—remains unchanged regardless of the product being produced or the size and shape of the container. The main idea is that the interface between the container and the machine is always the same. However, other parameters, such as the flow rate, temperature, and total volume of the injected fluid, are modified depending on the ingredient being processed and, therefore, on the food product or beverage being produced. The container preferably includes identification means for the beverage machine to automatically identify the type of ingredient contained therein and adapt its settings for optimal beverage preparation. Such settings include, but are not limited to: water injection pressure, water injection volume, water temperature, dispensing sequence (complex sequence of water injection, air injection, beverage dispensing, sequentially or simultaneously), air injection along with the water (to enhance foam), and total extraction time. Such identification means are selected from the following list: mechanical codes, optical codes (including color codes and codes printed with invisible ink), RFID tags, one-dimensional barcodes, two-dimensional barcodes, magnetic codes, conductivity codes, detection holes, or any combination thereof. As illustrated in the accompanying figures, in a preferred embodiment, the container has a flat shape oriented along a plane that is essentially vertical during beverage production, and the fluid injection element of the beverage machine is inserted into the container in such a way as to direct the jet of aqueous and / or gaseous fluid in a direction contained within that plane of the container. The fluid jets introduced from the bottom into the container develop in circular and spiral motions that create turbulence, friction, and high contact surfaces between the fluid molecules and the ingredient particles. On average, the fluid molecules rotate several times within the container before exiting together as a finished beverage or food product. A preferred embodiment of the packaging according to the invention will now be described with reference to the figures. In this preferred embodiment, the packaging is a small sachet. Figure 1 shows the closed flexible or semi-flexible container 1 for containing an ingredient according to the invention. Said container 1 comprises: (i) flexible or semi-flexible side walls 2 forming a flattened container body, and (ii) a cup-shaped lower portion 3 that is a hollow volume, and adapted for the insertion of a fluid injection element of the food or beverage preparation machine (not illustrated) to which said container 1 is designed to be connected. The hollow, cup-shaped lower portion 3 does not necessarily form the entire bottom of the container. In the embodiment shown in Figure 1, it forms only a central portion of the entire bottom of the container and is surrounded by the container's side edges 4, which are sealed, flat areas. The container 1, which is formed from an elongated, one-piece, flat primary preform sheet 5 made of flexible material, is illustrated in Figure 2. The manufacturing process steps and the manufacturing machine will be described in more detail later. The primary flat preform sheet 5 of paper-based material is U-shaped, folded around its transverse axis of symmetry Lx, and then sealed along its side edges 4 and top edge 6. According to a general principle of the invention, as illustrated in Figures 3A and 3B, the lower cup-shaped portion 3 is a hollow volume having a concave lower side 7 and convex side sides 8, and the profile curvature P,w of said concave lower side - visible when the container is viewed from the side as illustrated by a thick line in the profile view of Figure 3B - is identical to the profile curvature Pii of each of said side sides - visible when the container is viewed from below as illustrated by a thick line in the bottom view of Figure 3A -. More precisely, in the form illustrated in Figures 1, 3A, 3B, and 5, the lower cup-shaped portion is a hollow volume in the shape of a hexagonal prism. This prism has two opposing vertical edges 9 aligned with the transverse axis of the container Lx. These vertical edges 9 extend to form downward-projecting points 10. The extended edges 9 have a height such that, for each cross-section of the container measured along its transverse axis Lx, the sum of two heights of the lower cup-shaped portion plus the width of its lower side is constant. An example of this rule is illustrated in Figures 3A and 3B. Figure 3A shows a first width W1 of the lower side measured at a first cross-section of the lower portion. Figure 3B shows a first height H1 for the lower cup-shaped portion, measured for the same first cross-section.Figure 3A further shows a second width W2 of the lower side measured on a second cross-section of the lower portion. Figure 3B also shows a second height “H2” for the lower cup-shaped portion, which is measured for the same second cross-section. If the sum S1 = (2xH1)+W1 is calculated, and then S2=(2xH2)+W2, according to the principle of the invention, S1=S2 and, more generally, S1=S2=Sn (with Sn being measured at any point on the cross-section of the lower cup-shaped portion 3). The one-piece elongated primary flat preform sheet 5 used to manufacture the container 1 is made of a paper material coated on its inner side (i.e., the side that will be the inner side of the container 1 after the formation of said sheet 5) with a sealing layer. Furthermore, in the present embodiment of the invention, the primary flat preform sheet 5 further comprises a barrier coating sandwiched between the fiber-based material and the sealing layer. This barrier coating is an oxygen and moisture transfer coating. The barrier coating is selected from the following list: metallization coating, silicon oxide (SiOx) coating, aluminum oxide (AlOx) coating, atomic layer deposition (ALD) coating, or a combination thereof. In a preferred embodiment of the invention, illustrated in Figure 2, the container 1 further comprises a secondary reinforcing sheet of thickness 11 located on the inner surface of the lower, cup-shaped portion 3 of said container. The reinforcing sheet of thickness 11 is made of a paper material coated with a sealing layer. This reinforcing sheet of thickness 11 allows for a reduction in the thickness of the side walls 2 of the container 1. Reducing this thickness makes these side walls much more flexible, which has been found to be advantageous for improving the quality of the product prepared within the container 1. More specifically, the applicant has surprisingly discovered that the rotational movement of the fluid injected into the container is improved, since the side walls 2 of the container can flex and deform outward during beverage preparation.This deformation temporarily increases the internal space of the container compartment between the container's side walls 2. However, maintaining good rigidity of the lower, cup-shaped portion 3 is essential, as explained above (to maintain a proper seal at the interface between the container and the beverage preparation machine, and also to ensure that the container does not deform or collapse when pierced by the machine's fluid injection element, which would compromise or even prevent the piercing operation). The presence of the secondary-thickness reinforcing sheet 11 allows for a balance between the flexibility of the container walls and the rigidity of its lower portion. Advantageously, container 1 further comprises centering the transverse holes 12, illustrated in Figures 1, 3B and 5, which are located on the sealed edges 4 of said container 1. These holes are adapted in shape and diameter to accommodate centering pins (not illustrated in the figure) of the beverage preparation machine, to prevent movement of said container 1 in relation to the machine, during beverage preparation and, especially, during the insertion of the fluid injection element of the machine through the wall of the container. In a highly desirable embodiment, the concave lower side 7 of the container 1 comprises a flat portion 13 centered through the transverse and longitudinal axes of the cup-shaped lower portion 3, as illustrated in Figures 1 and 5. As illustrated in Figure 4, in a preferred embodiment, the container 1 further comprises a thin tertiary layer between the material that makes the container walls and the secondary reinforcing layer of thickness 11. This thin tertiary layer is produced by sealing or otherwise coupling a tertiary flexible flat preform sheet 14 between said primary flexible flat preform sheet 5 and a secondary flexible flat preform sheet 11. Said tertiary flexible flat preform sheet 14 is a thin layer selected from the list of: polyethylene (PE), polypropylene (PP), polylactic acid (PLA), polyhydroxyalkanoates (PHA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyvinyl alcohol (PVOH), starch-based polymers, a polymer comprising food-grade oxygen and / or moisture scavengers, or a combination thereof. It is preferably made from blown or cast polymer film having stretch properties. In this embodiment, as shown in Figure 4, the primary sheet 5 comprises a primary hole 15 that is perforated through its entire thickness. This primary hole 15 has a diameter chosen to be at least equal to, but preferably slightly larger in cross-section (or diameter) than the outside diameter (or cross-section) of the injection means of the beverage machine (which is typically a needle). Having a larger diameter prevents the material, such as paper fibers, from separating due to friction when the injection means are inserted through it. Typically, the diameter of the hole (which is preferably cylindrical) is between 1 mm and 20 mm, preferably between 5 mm and 12 mm. Furthermore, the secondary sheet 11 comprises a secondary hole 16 that is perforated at least through the paper layer of said sheet 11. The secondary hole 16 can also be perforated through the entire thickness of the secondary sheet 11. The diameter of the secondary hole 16 is chosen in relation to the diameter of the fluid injection element of the machine to which the container will be connected and is typically cylindrical with a diameter between 1 mm and 20 mm, preferably between 5 mm and 12 mm. The diameter of the primary hole 15 is equal to or greater than the diameter of the secondary hole 16 in the secondary flexible flat preform sheet 11. With this multi-layered construction, illustrated in Figures 4 and 5, which has three overlapping layers in the lower, cup-shaped portion 3 of container 1, a seal is ensured between container 1 and the machine's fluid injection element. When the machine's fluid injection element is inserted through the container wall, it passes through the primary orifice 15 and then perforates the tertiary sheet 14, which is preferably—as mentioned earlier—a stretchable material, such that the edges of the perforated sheet 14 fit closely to the surface of the fluid injection element. Finally, the fluid injection element moves through the secondary orifice 16 so that its tip is located inside the inner compartment of the container, establishing a hermetic fluid connection between the inside of container 1 and the machine's fluid supply circuit. This configuration also has the advantage that it requires low resistance to perforation of the container wall by the fluid injection element, because the total thickness of the container in the region of holes 15, 16 and the tertiary sheet 14 is only that of the latter, while at the same time, the entire portion of the container surrounding this region has a greater thickness, hence mechanical resistance to deformation, due to the presence of the three overlapping layers in the lower cup-shaped portion 3 of the container. In yet another preferred embodiment, illustrated in Figure 4, the secondary-thickness reinforcing sheet 11, once perforated with a hole 16, is further processed using a cutting tool that makes a plurality of radial cuts 22 extending radially outward from the edge of the hole 16. These radial cuts 22 create a series of fins between them, which have been found to strengthen the application of the container wall and, in particular, the tertiary flexible layer 14 to the outer surface of the machine's fluid injection element, once the machine and container are connected. Therefore, this plurality of radial cuts 22 enhances the leak-proof effect. The container described above is manufactured using a forming machine illustrated in Figure 6. Generally, such a machine is based, in part, on forming and sealing machines known in the art. First, it comprises a feeder portion of the primary flexible flat preform sheet 17, which is adapted to receive the primary flat preform sheets - and, optionally, secondary and tertiary - 5, 11, 14, preferably in the form of film rolls as shown in Figure 6. At this stage, and as indicated above, the secondary and tertiary flat preform sheets, if present, can already be assembled together with the primary sheet 5 or, alternatively, as illustrated in Figure 6, they can be supplied as separate rolls of material, a roll 18 for the primary sheets, a roll 19 for the secondary sheets and a third roll 20 for the tertiary sheets.In this case, the primary, secondary, and tertiary sheets are unrolled, cut into small flat preforms, the primary and secondary holes 15 and 16 are punched through, respectively, the primary and secondary preforms as described above, and then, finally, all the preforms are sealed together in an arrangement already described in relation to Figure 4. The arrangement of individual primary flat preform sheets 5 to be cut from the corresponding roll of material 18 is illustrated in Figure 7. The manufacturing machine further comprises a fixed container forming portion 21. Downstream, the container forming portion 21 is a filling and sealing portion 22 (wherein the container is filled with the ingredient and then closed by sealing the top edge of said container). Formation portion 21 is illustrated in greater detail in Figures 8 to 22 As shown in Figure 8, the forming portion of the machine comprises a forming plunger 23 and a forming cavity 24 that are movable relative to each other and have complementary shapes. The cavity 24 is a cylinder whose tip is hollowed out in a shape complementary to the outer shape of the lower end 25 of the plunger. This principle of a forming station with a movable plunger and cavity for deforming a material placed between them is generally known, and its details will not be described further. The end portion of the plunger 23 (i.e., its lower end), as illustrated in Figure 9, has a volumetric shape with a concave lower end 26 and convex side sides 27, such that the profile of its end side 26 is identical to the profile of each of its side sides 27.The principle of geometric equivalence between profiles 26 and 27 is the same as that previously described for the Pity P / w profiles of the lower cup-shaped portion 3, in relation to Figures 3A and 3B. In one particular embodiment, the end portion 25 of the piston 23 has a hexagonal prism shape. This prism has two opposing vertical edges 28 aligned with the piston's transverse axis Lx, extending downwards to form downward-extending points 29. These extended edges 28 have a height such that, for each cross-section of the piston measured along its transverse axis Lx, the sum of two heights of the end portion 25 plus the width of its lower side is constant. This principle is the same as that described above for the heights H1 and H2 and the widths W1 and W2 of the lower cup-shaped portion 3, in relation to Figures 3A and 3B. Preferably, the tips 29 of the plunger are rounded or have smooth edges, otherwise. As illustrated in Figure 9, the lower end 26 of the plunger preferably comprises a retractable projection 30 that aligns with the center of the plunger 23. This projection 30 is spring-mounted to retract into the plunger 23 when pressed against a surface, in this case, the lower primary flat preform sheet 5 and forming station cavity 24. This projection has a diameter larger than the diameter of the primary bore 15 and the secondary bore 16 described above. Its function is to gently press against the preforms 5, 11, and 14 before the plunger begins to deform them.When the forming process begins and the preform sheets start to deform, it holds the three preform sheets together in their sealed region (around holes 15 and 16 as described above), to prevent separation and slippage due to the mechanical forces applied to the material during the forming stage. The machine further comprises an actuator (not illustrated) for moving the plunger 23 and the cavity 24 towards each other, and also in relation to the preform sheet 5 that is placed between the two as shown in Figure 8. As shown in Figures 15 to 19 and 21, the machine further comprises a pair of plates adapted to support said flexible preform sheet 5. Both plates are coplanar at the start of the forming process, as illustrated in Figure 15. Each plate supports a fin of the primary flexible preform sheet. Said plates 31 can be fixed as illustrated in Figures 8 and 10 to 14. Alternatively, in another possible embodiment, the plates 31 are symmetrically rotatable about respective axes, each located on either side of said plunger 23, as shown in Figures 16 to 19 and 21, which depict various positions of said rotatable plates 31 during the forming process. The primary flat preform sheet 5 being processed is then considered to also comprise the secondary preform sheets 11 and tertiary preform sheets 14 attached to it, as described above. Once the preform 5 is conveyed along the machine to the forming portion 21 of the machine and is in position between the plunger 23 and the cavity 24, as shown in Figure 8, the stages of the forming process are as follows, in order. The plunger 23 moves downwards until it comes into contact with the upper surface of the preforms 5, 11 and 14, as shown in Figures 10 and 11; The movement of the plunger begins to deform these preforms which fold around the transverse axis Lx of the primary preform 5; after coming into contact with the upper surface of preforms 5, 11 and 14, due to the counterpressure of the lower cavity 24, the retractable projection 30 of the plunger 23 retracts into the latter as shown in Figure 11. The plunger 23 continues to move downwards and the cavity 24 also moves downwards, as shown in Figure 12. Both pull the preforms 5, 11 and 14 downwards as the latter are squeezed between the plunger 23 and the cavity 24. During the previous steps, a pair (or set) of sealing jaws 32 are positioned from each side of the cavity 24, which are adapted to seal the lateral edges of the preform sheet 5 once they are folded into a U shape. During the previous forming stages, the jaws are in the open position, i.e., away from the plunger, cavity, and preform assembly. After the cavity and plunger moved downward as described above, the jaws 32 move toward each other to close around the lower portion of the preform, as illustrated in Figure 13 and Figure 20. These seal (by the process of ultrasonic sealing or heat sealing) the side edges of the U-shaped folded preform to complete the formation of a sealed, fully formed, cup-shaped lower portion 3 of the container 1. Next, the jaws 32 reopen and the plunger 23 moves upwards along with the partially folded and sealed container 1, as shown in Figure 14. A variation of the same forming sequence described above is illustrated in Figures 15 to 19 and 21, with the difference that the support plates 31 pivot during the movement of the plunger and cavity, to guide the folding of the free ends of the U-shaped preform. Finally, as shown in Figure 15, the container is folded into a U-shape completely with still unsealed side walls 2 forming a flattened container body, and a sealed cup-shaped lower portion 3 which is a hollow volume shaped like said piston. Next, it is transferred to a sealing station that has elongated sealing jaws 33 that seal the side edges 4 of container 1, as shown in Figure 22. Container 1 is now ready to be filled with an ingredient and then closed by closing its top edge 34. In the embodiment where the lower cup-shaped portion of the container 3 has an improved wall thickness by coupling the secondary and tertiary layers 11 and 14 as described above, the primary, secondary, and tertiary flat preform sheets 5, 11, 14 can be coupled together at the time the primary sheet 5 is manufactured as a film roll (at the film manufacturer's facility) or, alternatively, the secondary and tertiary flat preform sheets 11, 14 can be coupled to the primary flat preform sheet at a later stage, just before the latter is formed (i.e., on the container manufacturing line). According to the present invention, the food or beverage ingredient packaged in the container is a water-soluble powder or a soluble concentrate in liquid or semi-liquid form, selected from the following list: soups, fruit juices, vegetable juices, broths, coffee, chocolate, tea, milk or cream substitute, smoothies, purees, coulis, creams, or a combination thereof. Preferably, the food or beverage ingredient is a soluble food or beverage ingredient selected from the following list: instant coffee powder, milk powder, cream powder, instant tea powder, cocoa powder, soup powder, fruit powder or a mixture of such powders, a coffee concentrate, a milk concentrate, a syrup, a fruit or vegetable concentrate, a tea concentrate, a fruit or vegetable puree. The container may also contain plant leaves for infusion, such as tea leaves, for example. Powders can be agglomerated or sintered. Liquid powders or concentrates can be mixed with solid pieces, for example, to prepare soups with solid pieces or encapsulated ingredients. The food or beverage ingredient can also be an infusion-based ingredient, such as roasted and ground coffee or tea leaves. In this case, the water extracts the infusion-based ingredient. In the present invention, the fluid covers any aqueous diluent that can be mixed with a soluble beverage ingredient to prepare a beverage, such as water, carbonated water, milk, etc. (preferably, water is the preferred aqueous diluent) or any gaseous fluid such as, for example, air. When referring to an aqueous fluid, water is the preferred fluid; when referring to a gaseous fluid, air is the preferred fluid. According to the invention, the container is essentially arranged vertically during the production and dispensing of the food or beverage product. According to the present invention, the aqueous fluid, typically water, is supplied in the container at any temperature: cold, ambient or hot, depending on the type of food product or beverage to be prepared. In contrast to prior art systems where the fluid is introduced from the top to the bottom, this beverage preparation machine injects water—and optionally air—from the bottom to the top of the container at high velocity. This allows for optimal turbulence within the container compartment and, therefore, optimal dissolution of the ingredient inside. If air is also injected with the water through the machine's injection system, it is not introduced at high pressure; the pressure is preferably between 0.1 and 1.5 bar, and more preferably between 0.3 and 0.5 bar. According to the invention, optimal turbulence and ingredient dissolution are achieved by high velocity, not high pressure. It should be understood that several changes and modifications to the preferred embodiments described herein will be obvious to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its accompanying advantages. Therefore, the appended claims are intended to cover such changes and modifications.

Claims

CLAIMS 1. A closed flexible or semi-flexible container (1) for containing an ingredient for preparing an edible product in a food or beverage preparation machine, by mixing the ingredient with a mixing fluid injected into the container by the machine, the container (1) comprising: (i) flexible or semi-flexible side walls (2) forming a flattened container body, and (ii) a cup-shaped lower portion (3) adapted for the insertion of a fluid injection element of the machine, the container (1) being formed from an elongated one-piece primary flat preform sheet (5) made of flexible material, preferably a fiber-based material, which is folded into a U-shape about its transverse axis of symmetry (Lx), and sealed along its lateral (4) and upper (34) edges, characterized in that the cup-shaped lower portion (3) is a hollow volume having a concave lower side (7) and convex side sides (8),and the profile curvature of the lower side (7) is identical to the profile curvature of each of the lateral sides (8).

2. A container (1) according to claim 1, characterized in that the lower cup-shaped portion (3) has a hexagonal prism shape, the prism having two opposite vertical edges (9) aligned with the transverse axis of the container (Lx), extending downwards to form downward-extending points (10), the extended edges (9) having a height such that, for each cross-section of the lower cup-shaped portion (3) measured along the transverse axis of the container (Lx), the sum of two heights of the lower cup-shaped portion plus the width of its lower side (7) is constant.

3. A container (1) according to any one of claims 1 or 2, characterized in that the one-piece elongated primary flat preform sheet (3) is made of a fiber-based material coated on its inner side with a sealing layer, the fiber-based layer being selected from the list of: paper, cardboard, cabasse-based material, bamboo-based or starch-based material, cellophane, or a combination thereof.

4. Container (1) according to claim 3, characterized in that the primary flat preform sheet (3) further comprises a barrier coating sandwiched between the fiber-based material and the sealing layer, the barrier coating being a coating against oxygen and / or moisture transfer, and is selected from the list of: metallization coating, silicon oxide (SiOx) coating, aluminum oxide (AlOx) coating, atomic layer deposition (ALD) coating, or a combination thereof.

5. Container (1) according to any one of the preceding claims 1 to 4, further comprising a secondary thickness reinforcing sheet (11) located at least on the inner surface of the lower cup-shaped portion (3) of the container, the secondary thickness reinforcing sheet (11) being made of a fiber-based material coated with a sealing layer, the fiber-based layer being selected from the list of: paper, cardboard, cabasse-based material, bamboo-based or starch-based material, cellophane, or a combination thereof.

6. Container (1) according to any one of the preceding claims 1 to 5, comprising identification means selected from the list of: mechanical codes, optical codes (including color codes and codes printed with non-visible ink), RFID tags, one-dimensional barcodes, two-dimensional barcodes, magnetic codes, conductivity codes, detection holes, or any combination thereof.

7. Container (1) according to any one of the preceding claims 1 to 6, further comprising centering the transverse holes (12) located on the sealed edges (9) of the container, the centering holes (12) being adapted for the insertion of centering pins of the beverage preparation machine, to prevent movement of the container (1) in relation to the machine, during beverage preparation.

8. Container (1) according to any one of the preceding claims 1 to 7, characterized in that the concave lower side (7) comprises a flat portion centered through the transverse and longitudinal axes of the cup-shaped lower portion (3).

9. Container (1) according to any one of the preceding claims 1 to 8, which is a sachet or a bag.

10. Container (1) according to any one of the preceding claims 1 to 9, characterized in that the ingredient is a water-soluble powder, or a soluble concentrate in liquid or semi-liquid form, selected from the list of: soups, fruit juices, vegetable juices, broths, coffee, chocolate, tea, dairy components such as milk or cream substitute, smoothies, purees, coulis, creams or a combination thereof, or the ingredient comprises plant leaves adapted for infusion in water.

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