LIQUID CONTAINER WITH INTERNAL MENISCUS, METHOD AND DEVICE FOR CONSTRUCTING SUCH A CONTAINER

Abstract

TITLE: LIQUID CONTAINER WITH AN INNER MENISCUS, METHOD AND DEVICE FOR MAKING SUCH A CONTAINER. The method (60) for manufacturing a food or pharmaceutical liquid container comprises: - a step (61) of manufacturing an empty tube having a reduced surface area at its opening, - a step (62) of filling the tube, and - a step (63) of sealing the tube by welding a lid onto the tube opening. During the sealing step (63), the tube is lidded by magnetic induction and pressure is applied to the lid on the tube opening. A capping machine is used, configured so that the magnetic induction flux is reduced, with respect to the inside of the tube, compared to the magnetic induction flux with respect to the tube wall. (Figure for the abstract: Figure 16)

Description

Title of the invention: LIQUID CONTAINER WITH INTERNAL MENISCUS, METHOD AND DEVICE FOR CONSTRUCTING SUCH A CONTAINER Technical field of the invention

[0001] The present invention relates to a liquid container with an internal meniscus, a method and a device for constructing such a container. It is particularly applicable to the preparation of doses of medicines and oral products, for example food supplements or energy drinks. State of the art

[0002] Traditionally, containers for doses of liquid medications and dietary supplements were cylindrical glass ampoules with two points. Their advantages include their ability to contain a single material, i.e., a uniform substance, the impermeability of glass to both gases and liquids, and their low cost. However, glass ampoules with two points have several disadvantages. First, glass is a brittle and heavy material, which therefore imposes significant logistical constraints. In addition, once opened by breaking one of their points, these ampoules can cause cuts to the user's skin. There is also a risk that, when opening by breaking a point, glass fragments will accompany the liquid and be swallowed by the user, with the risk of cuts to their digestive system.Glass also does not allow for printing or decoration other than monochrome and low resolution.

[0003] An evolution of this two-pointed bulb is the cylindrical glass "bottle" bulb with a single point. This bulb has the same drawbacks as the two-pointed bulb. Furthermore, its manufacture is more expensive than that of the two-pointed bulb.

[0004] Bottles made of synthetic material have also been used. These are single-dose containers made of synthetic material with screw caps. The advantages of these bottles are that they are robust and unbreakable, can be filled individually, and can be decorated in four-color process by applying a label. However, their synthetic material does not constitute a barrier to atoms or molecules, which can lead to deterioration of their contents, or even the formation of undesirable or dangerous molecules, for example, through oxidation or penetration of atoms or molecules from the adhesive or dyes of the label. Furthermore, these bottles are not sterilizable and their production cost is high.

[0005] Unicadose® units have the advantage of being robust and sterilizable, but with risks of deformation and leakage. Their main disadvantages are as follows. Their material does not constitute a barrier to atoms or molecules, particularly in their breakable area, which is extremely thin (on the order of a few hundredths of a millimeter thick), thus increasing oxygen porosity. Since their seal is achieved by interlocking, they present risks of leakage and the presence of liquid in the assembled section. Their production cost is high. Their breakability is not controlled because the reduced material thickness at the opening varies with mold wear. Their filling is collective or semi-collective, resulting in highly heterogeneous dosing with a significant risk of non-compliant filling. Their decoration is necessarily monochrome.

[0006] Sticks® are flexible aluminum containers. They have the advantages of being robust and single-use. They can be decorated in four-color process, and their walls provide barriers to atoms and molecules, including oxygen. However, they have several disadvantages. They are not sterilizable, which necessitates the use of preservatives. They have a small capacity, and opening them is difficult for the average user. Summary of the invention

[0007] The present invention relates to the manufacture of containers for liquids, for example single-dose liquid food supplements (a single, consumed dose), which meet all or part of the following criteria: - robust, - sterilizable, - decorative, - easy to open by any user, - economic, - whose dosage is reliable, and - of which more than 90% of the surface constitutes a barrier to atoms and molecules, including oxygen.

[0008] According to a first aspect, the present invention relates to a container in the form of a polypropylene tube sealed with an aluminum film. To ensure the quality of the assembly of these materials, and to guarantee the perfect seal of the container, despite the thermal and mechanical stress due to the sterilization process, while allowing tool-free opening for the consumer, and respecting production rate constraints, the use of a direct thermal head is impossible. Indeed, on a filled container, the heat required to melt the materials propagates to all parts near the punch. The expansion of the residual air chamber above the resulting liquid creates an increase in pressure in the tube which, in turn, generates a thrust on the operculum when heated.

[0009] When the punch is removed from the head, while the polypropylene is still molten, this pressure causes the seal to detach. Therefore, a seal cannot be achieved.

[0010] According to embodiments of the invention, an induction sealing head is used. With this technology, the lid becomes the hot part of the process. The induction field is directed primarily towards the contact areas at the periphery of the lid in order to reduce heat loss. This has the effect of limiting the heating of the residual air chamber. To achieve this peripheral induction, an element is provided that disrupts the magnetic field, for example, graphite positioned at the periphery of the inductor.

[0011] Preferably, the lid is made of aluminum co-extruded with a layer of polypropylene, which allows the fusion of this layer and the polypropylene of the tube.

[0012] In some embodiments, once the fusion and therefore the assembly is complete, the induction is stopped and the punch in the head remains under pressure until the polypropylene has cooled. Since the polypropylene is no longer molten when the punch is withdrawn, and the air pressure is almost zero, nothing disturbs the bond and the resulting seal is controlled.

[0013] Furthermore, the use of this technology allows for a higher production rate and eliminates the need for temperature management (preheating, cooling, and reheat control throughout production). Managing the power and time parameter values ​​of the phases, combined with air cooling during rest phases in the cycle, ensures reproducible operations throughout the entire production process with very high precision.

[0014] Another risk associated with heat sealing is that the diffusion of the molten material during the sealing process is not controlled. This creates excess material outside the cylindrical or conical tube, which can seep up onto the cap. This results in a significant increase in the tube's outer diameter, a rough finish, and considerable difficulty for the consumer to open the container. This highly variable problem cannot be resolved with conventional heat sealing.

[0015] According to another aspect of the invention, possibly complementary to the first, the quantity of material at the periphery of the tube in the sealing zone is reduced so that the excess molten material remains in the outer perimeter of the generatrices of the tube.

[0016] In embodiments of each aspect of the invention, the magnetic induction flux is directed so that melting occurs preferentially on the portion of the operculum facing the inner perimeter of the tube. The molten material on The pressure applied to the inner wall of the tube is therefore less intense than on its outer wall, causing the material to contract towards the center of the seal. Since only the seal is hot, no melting of the tube can occur outside the contact area of ​​the two parts.

[0017] All of these measures make it possible to increase the contact area between the tube and the lid for better sealing without degrading the ease of use of the lid when opened manually by a user.

[0018] According to a third aspect, possibly complementary to one or both of the first two aspects, an IML label (acronym for "In-Mold Labelling") is used for the decoration. This label allows for four-color process printing. The use of "crystal" polypropylene tubes, therefore without additives, is an undeniable qualitative advantage for the target market.

[0019] In some embodiments, the label is made of a "barrier" material or substrate, that is, one that does not allow oxygen to pass through its thickness. This characteristic solves the problem of polypropylene containers, which are relatively porous to oxygen.

[0020] It is noted that the use of other common materials such as PET (polyethylene), which may have better barrier properties, is incompatible with the sterilization heat treatment.

[0021] Preferably, the monodose of the invention is a relatively long and narrow tube, the dimension of which parallel to the axis of rotational symmetry is, for example, greater than five times the diameter.

[0022] However, to keep the IML label in the mold during material injection, the only known method is to charge the material with an electrostatic charge to force it to adhere to the mold walls. But, since the tube diameter is very small, the opposite walls of the mold cavity are very close and disrupt the homogeneous distribution of the label. This technology cannot therefore be used.

[0023] According to a fourth aspect of the invention, the label is held in place in the mold by means of venturi (air suction) through openings in the external mold.

[0024] In some embodiments, the label does not cover the entire circumference of the tube. The air suction device is then configured to be wide enough to allow air to pass through and provide sufficient suction without allowing the aspiration of material injected into the mold, which would clog the device if the label were missing or damaged during injection. Preferably, the diameter of the suction channels is between 5 and 15 microns. Preferably, the suction device comprises at least two channels per cavity of the single-cavity or multi-cavity mold, positioned near the ends of the part to be molded. Brief description of the figures

[0025] Other advantages, purposes and features of the invention will become apparent from the following description, given for explanatory purposes and in no way limiting the effect of the accompanying drawings, in which:

[0026] [Fig-1] represents, in axial section, a closed container which is the subject of the invention,

[0027] [Fig.2] represents a section identified in [Fig.1], of the container illustrated in [Fig.1],

[0028] [Fig.3] shows, in top view, a temperature distribution on the surface circular shape of a lid during the sealing of a container,

[0029] [Fig.4] represents, in cross-section, a first variant of a part of the mouth, before capping, of the container illustrated in figures 4 to 7,

[0030] [Fig.5] represents, in cross-section, a second variant of a portion of the mouth, before capping, of the container illustrated in figures 4 to 7,

[0031] [Fig.6] represents, in cross-section, a third variant of a portion of the mouth, before capping, of the container illustrated in figures 4 to 7,

[0032] [Fig.7] shows, in cross-section, the mouth portion illustrated in one of Figures 8 to 10, after capping,

[0033] [Fig.8] schematically represents a first step in the molding of a container, the subject of the invention, in a molding machine.

[0034] [Fig.9] schematically represents a second stage of molding a container that is the subject of the invention,

[0035] [Fig. 10] schematically represents a third stage of molding a container that is the subject of the invention,

[0036] [Fig. 11] schematically represents a fourth step in the molding of a container that is the subject of the invention,

[0037] [Fig. 12] schematically represents a fifth step in the molding of a container that is the subject of the invention,

[0038] [Fig. 13] schematically represents a machine for sealing a lid before welding it onto a container, which is the subject of the invention.

[0039] [Fig. 14] schematically represents the capping machine illustrated in [Fig. 14], during the welding of a lid onto a container that is the subject of the invention,

[0040] [Fig. 15] represents a timing diagram of the activation of components of a capping machine implemented in a particular embodiment of the process that is the subject of the invention,

[0041] [Fig. 16] represents, in the form of a flowchart, the steps of a manufacturing process for a container that is the subject of the invention,

[0042] [Fig. 17] is a photograph taken on the first day of a comparative stability study,

[0043] [Fig. 18] is a photograph taken on the third day of a comparative stability study,

[0044] [Fig. 19] is a photograph taken on the sixth day of a comparative stability study,

[0045] [Fig.20] is a photograph taken on the eighth day of a stability monitoring comparative, and

[0046] [Fig.21] is a photograph of the openings of a capping tube, of a tube capped and of a tube after removal of the cap.

[0047] Description of embodiments

[0048] Throughout the description, the following terms are used: - “Monodose”: a single-dose container made of synthetic material. - “Unit filling”: the action of filling the single-dose unit by unit, controlling the quantity of liquid inserted into the single-dose. - "Group filling": the act of filling single-dose containers collectively.

[0049] - "Sterilization": heat treatment at a temperature above 100°C and lasting between 12 and 30 minutes. - “Tyndallisation”: heat treatment at a temperature below 100°C (generally 70°C) for a duration of 60 mm repeated 3 times at 24 h intervals (Used for heat-sensitive raw materials and active ingredients). - “Barrier”: term used to describe the absence of oxygen porosity in materials.

[0050] In [Fig. 1], a container 20 (also called the "monodose" below), the subject of the invention, is observed in cross-section BB shown in [Fig. 2]. This monodose 20 comprises a tube 21 containing a liquid 22. The tube 21 is geometrically defined, at least at its opening: - for the outside of the tube, by generators of a cylinder or a cone called "external" and, - for the inside of the tube, by generators of a cylinder or a cone called "internal".

[0051] The tube 21 has a longitudinal axis 27 of rotational symmetry.

[0052] The lower opening of the tube 21 is sealed by a molded wall 23. The upper opening of the tube 21 is sealed by a lid 25 which a consumer can remove without a tool to consume the liquid 22. The lid 25 extends outwards from the tube 21 beyond the external generators of the tube 21. The wall of the tube 21 contains a barrier label 24. Preferably, the label 24 and the lid 25 together cover at least 80% of the surface of the container 20 and, even more preferably, at least 90% of this surface.

[0053] Figure 2 represents section AA, identified in Figure 1, of the single-dose unit 20. The barrier label 24 supports a "decoration" representing, in particular, the legal information. mandatory on a container of consumable foodstuff. In this particular embodiment, and preferably, label 24 is an IML label (acronym for "In-Mould Labelling"), which allows for four-color process printing. Thanks to this type of label 24, tube 21 can be molded from "crystal" polypropylene, therefore without additives, which constitutes a significant quality advantage for a container of consumable foodstuff. This IML 24 label, being made with a "barrier" support, solves the problem of porosity of polypropylene containers, which can lead, among other things, to oxidation of the components of liquid 22. Preferably, in order to limit sealing problems, the tube 21 is relatively long (more than 100 millimeters) and narrow (less than 20 millimeters and preferably less than 17 millimeters), for a volume of liquid 22 of 15 ml.

[0054] The manufacture of 15 ml single-dose units in pharmaceutical grade Polypropylene is described below, sealed using an aluminum lid co-extruded with a layer of polypropylene.

[0055] The assembly of these materials ensures a perfect seal for the container, despite the stress of the sterilization process, while allowing for tool-free opening by the consumer and respecting production rate constraints. It should be noted that the use of a direct thermal head is impossible on a filled container, as the heat required to melt the materials spreads to all parts near the punch, i.e., the moving part of the thermal head that comes into contact with the lid. This punch combines the functions of cutting the co-extruded aluminum ribbon with a layer of polypropylene as it passes through the die, transporting the lid to the container, and holding it in place during sealing and cooling. It should be noted that this punch is the only part that comes into contact with the lid, other than the container itself.

[0056] With a thermal head, heating the residual air chamber below the seal causes an increase in pressure within the tube, which in turn generates pressure on the seal during heating. When the punch is removed from the head, while the polypropylene is still molten, this pressure causes the seal to detach. Therefore, a seal cannot be achieved.

[0057] In the embodiment detailed here, an induction sealing head is used. With this technology, the seal becomes the hot part. The induction field is directed primarily towards the peripheral parts of the seal that are aligned with the tube's thickness at its opening, in order to focus heat generation on these areas. This has the effect of limiting the heating of the air chamber inside the tube. To achieve this localized heating, the magnetic field lines are opposed at the center of the seal by a low-permeability component. relative magnetic field, a diamagnetic part or a magnet whose field lines are opposite to the electrically induced magnetic field. Alternatively, two parallel magnetic fields of opposite directions are induced on the central part of the lid, for example with two coaxial coils of different diameters carrying currents in opposite directions.

[0058] Furthermore, once the fusion, and therefore the assembly, is complete, the induction is stopped and the punch in the head remains preferentially under pressure until the polypropylene cools and hardens. Since the polypropylene is no longer molten when the punch is withdrawn, and the relative air pressure inside the tube is almost zero, the risk of disrupting the connection between the tube and the cap is eliminated. The resulting seal is thus guaranteed.

[0059] In addition, the use of this induction sealing technology allows for a higher production rate and eliminates the need for temperature management (preheating, cooling and reheating control throughout production) required by other technologies.

[0060] Figure 13 schematically shows a capping machine 80 in its resting configuration, before cutting a lid and welding this lid onto a container 21. The machine 80 comprises a punch 81, movable in translation about a vertical axis 88 and equipped, on its axis, with a channel 82, for suction to retain a cut lid 25, or for air blowing to cool the punch 81. In its vertical translational movement, the punch 81 is guided by a punch guide 83. Between this punch guide 83 and a cutting die 84, a film 85 of metal co-extruded with a layer of the same plastic material as the tube 21 moves in horizontal translation. Preferably, this metal is aluminum and the co-extruded plastic material is polypropylene. The aluminum is located on the upper side of this film.This film 85 moves by a step corresponding to slightly more than the diameter of the operculum 25, each time the punch 81 is in its resting configuration illustrated in [Fig. 13].

[0061] Below the die 84 are successively a support 86 and an inductor 87. A tube 21, containing the liquid 22 and bearing the label 24, is positioned below the support 86. As the punch 81 descends, it cuts a disc 25 from the film 85 and lowers it against the tube 21, which remains fixed, as illustrated in [Fig. 14]. The inductor 87 heats the disc 25 in the area where it contacts the opening of the tube 21. This heating causes the material of the tube 21 to melt and the disc 25 to weld onto this opening. During this melting, the tube 21 is held under pressure on the disc 25 to ensure the formation of the meniscus 34.

[0062] The weld of the operculum 25 on the tube 21 thus includes a meniscus 34 on the inner wall of the tube 21 inside the volume defined by the internal generatrices of the tube 21. The volume of this meniscus 34 is at least twice greater than the volume of a possible meniscus on the outer wall of the tube 21, outside the volume defined by the external generatrices of the tube 21.

[0063] The heating and temperature control relates to the lid 25 and the punch 81. Specifically, the punch 81 is cooled during periods of inactivity of the inductor 87, with the aid of a compressed air injection. This prevents the punch 81 from tending to heat up during the sealing process of thousands of containers 20.

[0064] Figure 15 illustrates, on a timing diagram 50, the operating phases of various components of the machine 80 during a cycle of applying a lid 25 to a tube 21 to form a container 20. Curve 51 represents, on the one hand, the times when the punch 81 is in its rest position, curve 51 taking its high value at this time, and, on the other hand, the times when the punch is moving or in its lowered position, curve 51 taking its low value at this time. Curve 52 represents the times when the air cooling of the punch 81 is activated, curve 52 taking its high value at this time. Curve 53 represents the times when the lid 25 is cut and moved, curve 53 taking its high value at this time. Curve 54 represents the moments during which the aspiration of the operculum 25 is carried out via the channel 82, curve 54 taking its high value there.Curve 55 represents the times during which the operculum 25 is moved until it comes into contact with the tube 21, with curve 55 reaching its high value at this point. Curve 56 represents the times during which the operculum 25 is in contact with the tube 21, with curve 56 reaching its high value at this point. Curve 57 represents the times during which the inductor 87 is activated, with curve 57 reaching its high value at this point. It is observed that, for a duration 58, the operculum 25 is maintained in contact with the tube 21 and with the punch 81, while the inductor 87 is inactive. This duration 58 allows the operculum 25 and the molten material of the tube 21 to be cooled by the punch 81, which remains at a temperature below the melting point of this material.

[0065] For example, the heating time of the lid 25 by the inductor 87 is approximately 0.7 seconds for a three-second cycle. Thus, up to 2.3 seconds of a cycle are devoted to cooling. The punch 81 therefore quickly acquires its optimal temperature, after approximately two or three cycles. Preferably, during these initial two or three cycles, the values ​​of the parameters increasing the heating of the lid 25 are slightly increased to compensate for the lower temperature of punch 81, and avoid discarding the first 20 sealed containers at the start of production.

[0066] Managing the power and phase duration parameters, combined with air cooling during the intermediate phases between two induction phases in each cycle, ensures reproducible operations throughout the production process with very high precision. More specifically, the cooling of the lid 25 and the punch 81 is achieved by injecting air through the punch 81 during the intermediate phases between two induction phases.

[0067] Air is injected through the channel 82 of the punch 81 used for suction of the operculum 25, which allows the operculum 25 to be kept perfectly centered during the movement of the punch 81 between the die 84 and the mouth of the tube 21 to be sealed.

[0068] Preferably, during heat sealing, the direction of diffusion of the container material is controlled after melting. This prevents excess material from forming outside the volume defined by the curves of the cylindrical or conical tube. Indeed, this excess material can rise onto the lid by capillary action. It could therefore cause a significant increase in the tube's outer diameter, resulting in a rough finish and a risk of cutting the lips of the consumer who brings the container's opening to their lips. Furthermore, this excess material would increase the sealing surface area of ​​the lid and, consequently, make it very difficult for the consumer to open the container.

[0069] In the container 20 detailed here, the quantity of material is preferentially reduced at the periphery of the container before heat sealing, as illustrated in [Fig.4]: the internal diameter of the tube is, before capping, identical over the entire length of the tube 21, including its mouth, but the external diameter of the tube 21 is reduced near the mouth.

[0070] In geometric terms, the last section of the mouth of the tube 21 perpendicular to the axis 27 of rotational symmetry is separated from the external generatrices of the mouth of the tube 21 by a distance, measured on an axis of this section passing through the axis of rotational symmetry, at least equal to one fifth of the distance between the internal and external generatrices, i.e. the thickness of the tube 21. As a result, the surface area of ​​the section of the tube 21 perpendicular to the axis 27 of rotational symmetry is reduced, compared to sections of the tube perpendicular to the axis 27 of rotational symmetry further from this mouth.

[0071] In [Fig. 4], the reduction in the external diameter, in the form of a shoulder 30, is 0.5 millimeters. The thickness of the tube 21 thus decreases from 1.00 millimeters to 0.75 millimeters over the last half-millimeter of the tube 21 preceding its upper end. More generally, the longitudinal dimension of the part possessing a reduced external diameter, is preferably less than two millimeters and this reduction in diameter is less than half the thickness of the tube.

[0072] The external shoulder 30 located near the mouth of the tube 21 reduces, at this mouth, the surface area of ​​the section of the tube 21 perpendicular to the axis 27 of rotational symmetry, compared to sections of the tube 21 perpendicular to the axis 27 further away from the mouth.

[0073] In other embodiments, the reduction of the diameter at the mouth is progressive, for example in the form of several successive shoulders 31 and 32, as illustrated in [Fig. 5], or in the form of a cone 33 forming, in cross-section, a bevel on each edge of the tube 21, as illustrated in [Fig. 6]. The conical shape 33 reduces, at the mouth, the surface area of ​​the section of the tube 21 perpendicular to the axis 27 of rotational symmetry, compared to sections of the tube 21 perpendicular to the axis 27 further from the mouth.

[0074] Preferably, the length, parallel to the axis 27, of the area in which the surface of the section of the tube 21 perpendicular to the axis 27 is reduced, compared to sections of the tube 21 perpendicular to the axis 27 further from the mouth, is less than two millimeters.

[0075] As illustrated in [Fig. 7], thanks to the reduction in the external diameter of the tube 21 at its mouth, during induction heating, a meniscus, or rim, of material 34 is created inside the tube 21, which adheres to the lid 25. On the outside of the tube 21, the melting tube material does not extend, or only very slightly, beyond the generatrices of the cylinder or cone defining the tube 21. This ensures good adhesion of the lid 25 to the tube 21 while avoiding the formation of an unsightly external rim that could injure the consumer's lip when consuming the liquid 22.

[0076] In [Fig.21], a photograph shows, from left to right, the mouths of a tube 21 to be capped, a capped tube and a tube after removal of the caplet 25. There, we observe the shoulder 30, at the mouth of the tube 21 to be capped, and the meniscus 34, at the mouth of the tube after removal of the caplet, by hand, without a tool.

[0077] As can be understood from reading the preceding description, the reduction in diameter of the tube 21 at its mouth allows the excess molten material to be absorbed while remaining within the outer perimeter of the generatrices of the tube 21, cylindrical or conical.

[0078] The induction flux is directed so that melting occurs preferentially on the lid opposite the inner wall of the tube 21, the part of the lid opposite the outer wall of the tube receiving a weaker induction flux and therefore heating up less. Figure 3 shows, in a top view, the temperature distribution on the circular surface of a lid during the sealing of a container. The line The circular dashed line 26 represents the initial contact surface of the wall of the tube 21 with the operculum 25. The material, for example polypropylene, is therefore softer on the inner wall of the mouth of the tube 21 and is thus pushed towards the inside of the tube 21, while the outer wall of the mouth of the tube 21, being more rigid, does not deform beyond the generatrices of the tube 21.

[0079] Each of the sealing measures described above increases the contact surface area between the tube 21 and the lid 25 for improved sealing, without compromising the ease of use of the lid 25 when opening. Finally, the use of this peripheral induction technology reduces space requirements and allows for multiple stations on the industrial equipment.

[0080] We will now describe, with reference to figures 8 to 11, a molding machine 40 and the molding steps of the tube 21 having, in its thickness, the label IML 24. It is noted that these steps lead to the production of a tube 21 oriented in the opposite direction to its representation in figures 1 to 7, that is to say with its mouth at the bottom.

[0081] In [Fig. 8], the molding machine 40 shows a fixed part comprising an injection module 41, a steady rest 42, a Venturi suction channel 43 between the steady rest 42 and a die 44, and a Venturi suction channel 45 between the die 44 and a steady rest 45. Below this fixed part is a label 24 held by a cylindrical ejector tool (not shown) to have a diameter smaller than the diameter of a cavity 49 in the fixed part, which passes through the steady rests 42 and 45 and the die 44 and terminates below the injection module 41. Below the label 24 is a stripper 48 carrying a spindle 47. As shown by the arrows in [Fig. 8], the label 24 and the spindle 47 are designed to penetrate the cavity 49. The difference in radius between the spindle 47 and the cavity 49 This corresponds to the thickness of the tube to be molded.

[0082] In [Fig. 8], the mold comprising the die 44 and the glasses 42 and 45 is in the open position, and the label 24 is awaiting insertion into the cavity 49 of the mold. The glasses 42 and 45 are separated from the die 44 to create a two-millimeter gap for the suction channels 43 and 46. The stripper 48 is in the open position.

[0083] The positioning of the label 24 in the cavity 49 is performed by a Cartesian robot (not shown). This robot retrieves the label 24 from a distribution warehouse (not shown). The label 24 is wrapped around the cylindrical placement tool (for example, with a diameter of 15 mm). The label 24 is held onto this placement tool by vacuum. The width of the label 24 and the diameter of the placement tool are related. The diameter of the placement tool must be smaller than the diameter of the cavity. The label must be held over its entire surface, therefore its width must be less than or equal to the perimeter of the placement tool: if its width was greater than the perimeter of the dispensing tool, the additional label, called "overlap", would come into contact with cavity 49 of the mold when the label 24 was introduced.

[0084] The robot then positions itself in front of the mold cavity 49 when the mold is in the open position. The dispensing tool introduces the label 24 into the mold cavity 49 (for example, with a diameter of 16.9 mm). Once the label 24 is in position, the vacuum exerted by the dispensing tool is stopped and replaced by an air injection to detach the label 24 from the dispensing tool and press it against the wall of the cavity 49. The label 24 is then held in place by means of the two suction channels 43 and 46 positioned near the ends of the cavity 49. These venturis are obtained by dividing the cavity 49 into three parts. The bottom part, the injection module 41, which supports the injection nozzle, is fixed. The central part, which is conical and perfectly smooth, corresponds to the die 44. The lower part is cylindrical. The depression is achieved using channels 43 and 46 which are formed at the junction of these three parts.However, the second and third sections are slightly movable. When the mold is opened, each of these sections is separated by 2 mm from the previous one to maximize suction power. Once the label 24 is in place, the dispensing tool is removed and the mold can close. As it closes, the mold compresses the second and third sections to reduce the size of the venturi channels to a minimum (between 5 and 13 microns).

[0085] In the case of polypropylene injection, the dimension of 13 microns is the maximum size which allows for suction to hold the label without allowing the polypropylene to be sucked up and clog the channels 43 and 46 after a few injections.

[0086] In [Fig. 9], the label 24 is positioned in the cavity 49 of the mold, and the mold is being closed. The suction channels 43 and 46 are still in the open position. The suction they provide holds the label 24 in a cylindrical configuration against the wall of the cavity 49. This prevents the distance between the label 24 and the wall of the cavity 49 from varying along the different parts of the label 24. The stripper 48 is in the closed position. It presses against a cone on the spindle 47 to ensure its perfect centering and prevent the thickness of the tube to be molded from varying according to the angle around its longitudinal axis.

[0087] In [Fig. 10], the stripper 48 inserted the spindle 47 into the cavity 49. The suction channels 43 and 46 are closed by the thrust of the stripper 48, so that each channel 43 and 46 has an opening, measured parallel to the axis of the cavity, limited to a value between five and fifteen microns, typically eight or nine microns. The injection of the material begins to be carried out by the injection module 4L

[0088] In [Fig. 11], the mold is still closed and in the same configuration as in [Fig. 10]. The injection is complete. The die 44 and the spindle 47 are cooled by internal circulation of a chilled fluid. In [Fig. 11], for explanatory purposes, the tube 21 is shown with dashed lines.

[0089] Once cooling is complete, the stripper 48 and the mold return to the position shown in [Fig. 1], as illustrated in [Fig. 12]. [Fig. 12] shows that the tube 21 is detached from the spindle 47 by sliding the spindle 47 downwards within the stripper 48. Once the tube 21 is removed from the spindle 47, the cycle restarts with the positioning of a label 24 opposite the cavity 49, as illustrated in [Fig. 1]. The complete cycle lasts approximately ten seconds. [Fig. 12] also shows that the shoulder 30 has been molded into an annular cylindrical groove 59 in the stripper 48. This particular feature has, among other advantages, the advantage that the label 24, held in position in the cavity 49, is kept away from the sealing area molded in the stripper 48.

[0090] The tube 21 is conical, with an angle between its generatrices of 0.2 degrees and 0.4 degrees relative to the longitudinal axis of the tube 21. This is a physical requirement for molded parts. Technically, this is a draft angle. This draft angle ensures that, very quickly, the moving parts of the mold are no longer in contact with the molded part when the mold is opened. Without this draft angle, the frictional stresses would be too great, and the damage to the molded parts would be excessive.

[0091] The thickness is almost constant along the entire length of the tube, for example, approximately 0.8 millimeters. However, at approximately 14 millimeters from the end of the tube 21, the draft angle is abandoned in favor of a cylindrical profile. This results in a thickness of one millimeter at the rim of the container, before the shoulder 30. These geometric characteristics offer several advantages. Firstly, a thickness of one millimeter is preferable for obtaining the amount of material needed to seal the cap 25. Furthermore, this is the surface against which the stripper 48 rests to detach the tube 21 from the spindle 47 during the opening of the mold shown in [Fig. 12]. Switching to 0.8 millimeters, outside this defined area to meet these constraints, saves on the weight of material injected into the mold.

[0092] The molded wall 23 is the part where the material is injected. The profile of this part is very technical. The "skirt" that extends beyond the wall 23 of the tube 21 is a so-called "thief" end.

[0093] The objective of implementing the elements shown in figures 8 to 12 is to enable the positioning and retention of the label 24. This also allows the material injection flow to meet the label 24 perpendicularly in order to press the beginning of the label against the wall of the cavity 49 of the mold.

[0094] As can be understood from the description accompanying Figures 8 to 12, preferably, a mold is used that holds the label 24 by means of air suction (“Venturi”). Since the label 24 does not cover the entire circumference of the tube 21, each annular channel 43 and 46 of each venturi must be sufficiently wide to allow the passage of air and ensure a sufficient suction effect, without, however, allowing the suction of material that would obstruct this channel 43 or in the event of the absence or defect of the label 24 during injection. Preferably, the longitudinal dimension of each annular channel 43 and 46 is between 5 and 15 microns. At least two venturi suction channels are arranged on each external mold, near the ends of the internal cavity 49 of this mold.

[0095] The closing moving part of the mold consists of the spindle 47, which determines the internal profile of the single-dose tube 21, and the stripper 48, which is the last part of the mold (with regard to the parts in contact with the molded part). This stripper 48 has several functions.

[0096] The positioning of the label 24 is done with a small offset to prevent the application tool from interfering with the bottom (at the top in [Fig.9]) of the cavity 49. The stripper 48 allows the label 24 to be pushed to the bottom of the cavity 49 and its precise positioning.

[0097] It is also the stripper 48 that creates the particular profile of the rim (material removal shoulder to allow the sealing of the lid 25 without material overflow). The stripper 48 also allows the pin 47 to be precisely centered during injection. Finally, it allows the tube 21 to be detached from the pin 47 when the mold is opened.

[0098] The mechanical part that supports the dispensing tool, on its front face, is equipped with a gripper, on its rear face. When the mold is opened again, this gripper catches the molded tube 21, previously detached from the spindle 47 as shown opposite [Fig. 12].

[0099] The actions of applying the label 21 and retrieving the molded tube 21 are therefore performed simultaneously during the opening of the mold. This step lasts only 2 to 3 seconds. The injection and cooling steps take 7 to 8 seconds, with 5 to 6 seconds solely for cooling.

[0100] Possible technical specifications for the IML label are given below: barrier material, multilayer cast polypropylene (CPP) film (Polypropylene / Ethylene-vinyl alcohol EVOH / Polypropylene), with a thickness between 50 microns and 80 microns, for example 65 microns.

[0101] In embodiments and as illustrated in [Fig. 16], the process 60 for constructing a container 20 for packaging a preservative-free liquid comprises: - the manufacture of a synthetic material container fitted with an IML label, step 61, preferably as shown opposite figures 8 to 12, - filling this container, step 62, - the sealing of this filled container, step 63, preferably by induction and more particularly by peripheral induction as shown opposite figures 3 to 7 and 13 to 15, and - sterilization or tyndallization of the contents (in particular by autoclave), step 64.

[0102] Preferably, this process 60 of manufacturing a container 20 of liquid food or pharmaceutical 22, includes: - a manufacturing step 61 of an empty tube 21 having, at least at its mouth, a longitudinal axis 27 of rotational symmetry, the tube having, at this mouth, a cross-sectional area perpendicular to the axis of rotational symmetry, reduced compared to cross-sections of the tube perpendicular to the axis of rotational symmetry further from the mouth, and / or - a step 61 of molding an empty tube 21 in a mold 41 to 46 with molten plastic material, during which a barrier label 24 comprising a material more impermeable to at least one gas than the molten plastic material is held in the mold during the injection of the molten plastic material.

[0103] Preferably, during sealing step 63, the tube 21 is capped by magnetic induction and pressure is applied to the cap on the mouth of the tube.

[0104] Preferably, during the sealing step 63, a capping machine 80 is used, configured so that the magnetic induction flux is reduced, with regard to the inside of the tube 21, compared to the magnetic induction flux with regard to the wall of the tube.

[0105] Preferably, during sealing step 63, a capping machine 80 is used, configured so that the magnetic induction flux is higher with respect to the inner wall of the mouth of the tube 21 than with respect to the outer wall of the mouth of the tube.

[0106] Preferably, during the sealing step 63, a sealing punch 81 is used and put under pressure on the lid 25, and, once the magnetic induction is complete, the punch is kept under pressure on the lid.

[0107] Preferably, during the sealing step 63, the cooling of the punch 81 is done by injecting air through a channel 82 of the punch used for suction of the operculum 25 before its placement on the mouth of the tube 21.

[0108] Preferably, during step 61 of manufacturing the tube 21, the mouth of the tube is molded in an annular groove 59 of a stripper 48.

[0109] Preferably, during step 61 of molding the tube 21, the suction holding the barrier label 24 in position is carried out via at least one suction channel 43, 46 whose smallest void dimension is between 5 and 15 microns.

[0110] Preferably, during the molding step 61 of the tube 21, the suction holding the barrier label 24 in position is carried out by means of at least one annular suction channel 43, 46 located in a plane perpendicular to an axis 27 of rotational symmetry of the external wall of the mold, the dimension of which, measured parallel to this axis, is between 5 and 15 microns.

[0111] Preferably, during step 61 of molding the tube 21, at least two annular suction channels 43, 46 are used, positioned near the ends of the tube 21 to be molded.

[0112] Preferably, during the molding step 61 of the tube 21, the annular channels 43, 46 are formed in an intercalary manner between a bezel 42, 45 and a die 44, each bezel being movable relative to the die, between a position far from the die, implemented during a step of introducing the label 24 into the mold 41 to 46 and a position closer to the die, implemented during the injection into the mold of the molten plastic material.

[0113] Preferably, during step 61 of molding the tube 21, a stripper 48 carrying a spindle 47 is used, the movement of the stripper causing the glasses 43, 46 and the die 44 to come together.

[0114] Preferably, during step 61 of molding the tube 21, the mouth of the tube is molded in an annular groove 59 of a stripper 48.

[0115] Preferably, sterilization or tyndallization step 64 is a tyndallization step. Tyndallization is a heat treatment carried out by an autoclave using a temperature exposure / temperature ratio. This heat treatment is performed at a temperature below 100°C and, for example, for a duration of at least one hour, repeated three times at 24-hour intervals.

[0116] Preferably, step 64 of tyndallization comprises, three times at 24-hour intervals: - a preheating stage for the double wall of the autoclave, - an initial step of evacuating the autoclave chamber, to extract as much air as possible from the chamber, - a moderate steam injection stage while the vacuum process continues to replace all the air initially present in the chamber with saturated steam, - a heating stage of container 20 by more powerful steam injection to obtain a predetermined temperature and pressure, - a stage of maintaining the temperature and pressure of the chamber, by controlling the pressure of the chamber by balancing the injection of steam and the evacuation of the atmosphere, in such a way that the temperature is regulated, - a final stage of evacuating the autoclave chamber.

[0117] Preferably, the predetermined temperature is between 70 °C and 75 °C.

[0118] In the manufacturing unit, empty tubes are loaded in bulk by an operator at the line inlet, and filled, sealed tubes, stacked on a multi-tube rack, are received by this operator at the outlet. The production line comprises: - automatic feeding of empty tubes (unpacking, grouping on a motorized conveyor with suction, positioning in packaging buckets), - the filling, - capping, and - placing on a support for sterilization or tyndallization.

[0119] For sterilization or tyndallization, autoclaves are preferably used. These are rectangular tunnels with a sealed door on each side. The load is introduced at one end and removed at the other. They have a volume of several cubic meters.

[0120] For operation, the aim is to apply to each container (several tens of thousands for a load) a precise and controlled temperature for a variable duration depending on the temperature chosen; this is the exposure time / temperature ratio mentioned above.

[0121] We distinguish two types of treatment, those with a temperature below 100°C (minimum 70°C) which are called "tyndallisation" and those above 100°C (maximum 121°C) which are called "sterilisation";

[0122] The first steps are the same for both types.

[0123] 1 - Preheating of the double wall.

[0124] 2 - Initial vacuum which aims to extract the maximum amount of air from the chamber (typically 90%).

[0125] 3 - Vacuum and moderate steam injection which serves to improve the quality of The chamber atmosphere is created by injecting steam while maintaining a vacuum in the lower part of the chamber. As a result, all the cold air at the bottom of the chamber is extracted and eventually replaced by saturated steam. This is crucial for maintaining the temperature during the plateau phase.

[0126] 4 - Heating the charge by powerful steam injection. The aim being to obtain the desired temperature at the same time as the desired pressure.

[0127] 5 - Processing platform. This is the efficient part of the cycle that allows us to obtain the result of reducing the initial bacterial load (Reduction by a factor of 10 to the power of 12 for a 12-minute cycle at 121°C).

[0128] To obtain the regularity of the plateau, only the chamber pressure is adjusted by balancing the steam injection and the vacuum. It is the ideal gas law, PV=nRT, which allows regulation to the tenth of a degree in a very large volume, regardless of the desired temperature (pressure below the relative pressure for 70°C, 0.34 bar absolute, and above for sterilization, 2.049 bars for 121°C according to the Regnault table) and the initial temperature of the injected steam (approximately 170°C in our case).

[0129] 6 - Either cooling with injection of cold purified water then draining for the Sterilization, or final vacuum for Tyndallization. Safety and regulations do not allow us to open the autoclave if the internal temperature is above 90°C.

[0130] Sterilization generally lasts between 15 and 30 minutes (for example, for food supplements, 115°C can be applied for 20 minutes).

[0131] Tyndallization, on the other hand, lasts 60 minutes and the cycle must be repeated three times at 24-hour intervals. The aim is to alternate periods of heat stress and rest for the bacteria, which have the ability to protect themselves in case of attack. They cannot change states multiple times. Therefore, the first pass stresses them, and they can no longer protect themselves during the second pass. The third pass ensures their protection. Tyndallization is used for products whose active ingredients are heat-sensitive so that they are not destroyed during heat treatment (royal jelly or vitamins, for example).

[0132] Stability tests

[0133] Tests were carried out to compare the behavior of a packaged product: - in a 15 mL yellow glass ampoule, - in single-dose PPS® 10 mL, - in single dose according to the invention 15 mL containing a coloured IML label, - in single dose according to the invention 15 mL containing a white IML label, - in single dose according to the invention 15 mL without an IML label.

[0134] These tests were carried out on Royal Jelly Taurine Zinc. The purpose of this study is to present the results in order to observe the evolution of the product's color over time depending on the type of container. To avoid any microbiological risk that could compromise the study, the production of the Royal Jelly Taurine Zinc and the filling of the different containers were carried out on the same day.

[0135] Five different containers were used for this study, namely: - a 15 ml yellow glass ampoule. This is a container used on the market and known to be permeable to oxygen. - a single-dose PPS® 10 ml. This is a commercially available container known to be impermeable to oxygen (the material used is not an oxygen barrier). - the single-dose unit according to the invention, 15 ml containing a colored IML label, called a "teaster single-dose unit", - the single-dose according to the invention 15 ml containing a white IML label, - the single-dose according to the invention 15 ml without an IML label.

[0136] The single-dose units according to the invention, 15 mL, are composed of a PPMH350 polypropylene tube with or without an IML label and a co-extruded aluminum and polypropylene lid.

[0137] It should be noted that In-Mould Labeling (IML) allows for four-color process printing. It systematically includes a white backing and has the advantage of being oxygen-barrier. The various samples underwent tyndallization at 70°C for one hour, for three consecutive days. All containers were then placed in cartons and in an oven (oven temperature between 60°C and 75°C). Stability monitoring was carried out every two working days with a visual check of the color. Only the opaque PPS® unit-dose containers were checked, and only when a difference in shade was observed between them and the other containers.

[0138] Test procedure.

[0139] At the manufacturing level, for technical and ergonomic reasons, two 750 mL preparations were made: - Manufacturing 1 = Test IA, - Manufacturing 2 = Tests IB.

[0140] To prevent any cross-contamination, precautionary measures were implemented, including cleaning the work surface between each test. All raw materials used were in stock at the warehouse and had been released as compliant by the Quality Control laboratory. No anomalies were encountered during this step.

[0141] At the filling stage, to avoid any microbiological risk, the containers were filled and sealed on the same day as manufactured. For the 15 mL amber glass ampoules, these were filled under a vacuum chamber and sealed using a blowtorch. Sixteen 15 mL ampoules were filled. For the PPS® unit doses, they were filled manually using a pipette. Sixteen 10 mL PPS® unit doses were filled. For the 15 mL single doses according to the invention, they were filled... This was carried out using good manufacturing practices. The single-dose units were filled and sealed. The values ​​used for the sealing parameters are shown below:

[0142] Ten single-dose containers according to the invention containing a colored IML label, ten single-dose containers according to the invention containing a white label, and ten single-dose containers according to the invention without labels were filled. The filling steps were successfully completed, and no anomalies occurred.

[0143] Regarding the heat treatment, as specified above, the various samples underwent tyndallization (70°C for 1 hour for three consecutive days). The heat treatment took place in a production environment governed by Good Manufacturing Practices. All applicable rules, described in the laboratory procedures, for heat treatment were applied for these stability tests. This heat treatment was carried out in an autoclave. No anomalies were encountered during this phase. For the single-dose samples according to the invention, a leak test by passing through a vacuum chamber was performed for verification.

[0144] Regarding stability testing and stability monitoring, the various cartons were placed in an oven to simulate accelerated stability conditions and thus observe the behavior of the single-dose units according to the invention under the effect of heat (oven temperature between 60°C and 75°C). Stability monitoring was carried out by visually checking the color of all the containers. It should be noted that, since the PPS® single-dose unit is opaque, it is only checked when a color difference is observed between the different containers.

[0145] The analysis of the results is given below. Stability monitoring for this study was carried out over 7 days. The results obtained are presented in Figures 17 to 20.

[0146] Results J0: [Fig.17], with, from left to right: ampoule 91, single-dose PPS® 92, single-dose teaser 93, single-dose white label 94, single-dose without label IML 95. No significant visual difference in color was observed between the different containers.

[0147] Results J+2: [Fig.18], with from left to right: ampoule 91, single-dose without label IML 95, single-dose teaser 93, single-dose white label 94. No significant visual difference in color was observed between the different containers.

[0148] Results J+5: [Fig.19], with, from left to right: ampoule 91, teaser monodose 93, white label monodose 94, unlabeled IML monodose 95, PPS® undose 92. Initial color differences were observed during these J+5 checks.

[0149] The results show: - that the contents of the PPS® 92 unit-dose vials were much darker than those of the other containers. This observation highlights that the material used to make the PPS® 92 unit-dose vials is very porous and does not protect the product. Indeed, under the effect of heat, the product oxidizes much more rapidly in this type of container. - that the contents of the unit-dose vials according to the invention without an IML label are darker than the contents of the unit-dose vials according to the invention with a label, but not as dark as those of the PPS® 92 unit-dose vials. This finding demonstrates that the IML label plays an extremely important role in protecting the product from external conditions. No significant visual difference in color was observed between the vial and the unit-dose vials according to the invention with an IML label.

[0150] Day 7 Results: [Fig. 20], with, from left to right: ampoule 91, teaser single-dose 93, single-dose with white label 94, single-dose without IML label 95. The observations made during the Day 7 checks are quite similar to those at Day 5. There is little difference in color between the ampoule and the single-dose vials according to the invention with IML label.

[0151] Stability studies have shown that the color changes in the single-dose container according to the invention more rapidly than in the ampoule, without affecting the organoleptic and physicochemical properties. Depending on the type of container selected, the product's evolution over time differs. The PPS® single-dose container, while offering numerous advantages, is porous to air. Under the influence of heat, the product changes much more rapidly than in the ampoule or the single-dose container according to the invention.

[0152] The single-dose container according to the invention without an IML label is also porous to air. The presence of an IML label is important for protecting the product against external conditions. The ampoule is the container that exhibits a slower color change than the single-dose container according to the invention. However, it is worth noting that the color change observed in the single-dose container according to the invention with an IML label does not interfere with the organoleptic and physicochemical characteristics.

[0153] Object and invention

[0154] The present invention aims to remedy all or part of the disadvantages of the prior art set out above.

[0155] To this end, according to a first aspect, the present invention relates to a container for food or pharmaceutical liquid comprising: - a geometrically defined plastic tube, at least at its opening, with external generatrices of a cylinder or cone, and internal generatrices of a cylinder or cone said to be "internal", this tube having a longitudinal axis of rotational symmetry, this tube containing said liquid, and - a seal welded onto the mouth of the tube, this seal extending beyond the external generators on the outside of the tube;

[0156] container wherein the weld of this lid on the tube includes a meniscus on the inner wall of the tube inside the volume defined by the internal generators, the volume of this meniscus being at least twice greater than the volume of any possible meniscus on the outer wall of the tube outside the volume defined by the external generators.

[0157] Thanks to these arrangements, good adhesion of the lid to the tube is obtained, while avoiding the formation of an unsightly external rim that could injure the consumer's lip when consuming the liquid.

[0158] In optional embodiments, before welding the operculum, the last section of the mouth of the tube perpendicular to the axis of rotational symmetry is separated from the external generatrices by a distance, measured on an axis of this section passing through the axis of rotational symmetry, at least equal to one fifth of the distance between the internal and external generatrices, the surface area of ​​the section of the tube perpendicular to the axis of rotational symmetry being reduced, compared to sections of the tube perpendicular to the axis of rotational symmetry further from the mouth.

[0159] The inventor has discovered that this reduction in cross-section at the mouth can be sufficient to obtain the advantages of the present invention.

[0160] In optional embodiments, the tube has, before welding of the operculum, at least one external shoulder near the mouth, this shoulder reducing, at the mouth, the surface of the section of the tube perpendicular to the axis of rotational symmetry, compared to sections of the tube perpendicular to the axis of rotational symmetry further from the mouth.

[0161] Such a shoulder is easy to mold and its distance from the mouth allows the respective displacement of the capping punch and the tube to be calibrated during the melting of the tube material.

[0162] In optional embodiments, the tube has, before welding of the operculum, at least one conical shape reducing, at the mouth, the surface of the section of the tube perpendicular to the axis of rotational symmetry, compared to sections of the tube perpendicular to the axis of rotational symmetry further from the mouth.

[0163] Such a conical shape is easy to mold and its geometry allows the respective displacement of the sealing punch and the tube to be calibrated during the melting of the tube material.

[0164] In optional embodiments, before welding the operculum, the length, parallel to the axis of rotational symmetry, of the area in which the surface of the section of the tube perpendicular to the axis of rotational symmetry is reduced, compared to sections of the tube perpendicular to the axis of rotational symmetry further from the mouth, is less than two millimeters.

[0165] Thus, a very small distance is sufficient to obtain the advantages of the present invention.

[0166] In optional embodiments, the lid is made of metal co-extruded with a layer of the same plastic material as the tube. Preferably, said metal is aluminum and said plastic material is polypropylene.

[0167] Thus, the adhesion of the molten material of the tube to the lid is improved.

[0168] According to a second aspect, the present invention relates to a method for manufacturing a container for food or pharmaceutical liquid, which comprises: - a manufacturing step of an empty tube having, at least at its mouth, a longitudinal axis of rotational symmetry, the tube having, at this mouth, a cross-sectional area perpendicular to the axis of rotational symmetry, reduced compared to sections of the tube perpendicular to the axis of rotational symmetry further from the mouth, - a tube filling step and - a sealing step of the tube, by welding a cap onto the mouth of the tube.

[0169] The advantages, purposes and particular characteristics of this process being similar to those of the container which is the subject of the invention, they are not recalled here.

[0170] In optional embodiments, during the sealing step, the tube is capped by magnetic induction and pressure is applied to the cap on the mouth of the tube.

[0171] Thanks to this induction, only the lid heats up directly. This avoids heating the air trapped in the tube and the risk of the lid detaching.

[0172] In optional embodiments, during the sealing step, a capping machine is implemented configured so that the magnetic induction flux is reduced, with respect to the inside of the tube, compared to the magnetic induction flux with respect to the wall of the tube.

[0173] Thus, heating is focused on the part of the operculum in contact with the tube wall, which further reduces heating of the air inside the tube.

[0174] In optional embodiments, during the sealing step, a capping machine is implemented configured so that the magnetic induction flux is higher with respect to the inner wall of the tube mouth than with respect to the outer wall of the tube mouth.

[0175] Thus, the material of the tube melts more rapidly on the inner side of the tube, which promotes the formation of the inner meniscus mentioned above.

[0176] In optional embodiments, during the sealing step, a sealing punch is used and put under pressure on the lid, and, once the magnetic induction is complete, the punch is kept under pressure on the lid.

[0177] Thanks to these arrangements, the operculum and the molten material of the tube are rapidly cooled by the punch.

[0178] In optional embodiments, during the sealing step, the cooling of the punch is done by injecting air through a channel of the punch used for suction of the operculum before its placement on the mouth of the tube.

[0179] Thanks to these provisions, the design, manufacture and operation of the punch are simplified and the efficiency of its cooling is improved.

[0180] In optional embodiments, during the tube manufacturing step, the mouth of the tube is molded in an annular groove of a stripper.

[0181] The removal of the molded tube, on one side of the mold and, on the other side, of the stripper, is thus facilitated.

Claims

Demands

1. A method (60) for manufacturing a container (20) for food or pharmaceutical liquid (22), comprising: - a step (61) of manufacturing an empty tube (21) having, at least at its mouth, a longitudinal axis (27) of rotational symmetry, the tube having, at this mouth, a cross-sectional area perpendicular to the axis of rotational symmetry, reduced compared to sections of the tube perpendicular to the axis of rotational symmetry further from the mouth, - a step (62) of filling the tube and - a step (63) of sealing the tube, by welding a cap onto the mouth of the tube;a process in which, during the sealing step (63), the tube (21) is capped by magnetic induction and pressure is applied to the cap on the mouth of the tube, characterized in that, during the sealing step (63), a capping machine (80) is used, configured so that the magnetic induction flux is reduced, with respect to the inside of the tube (21), compared to the magnetic induction flux with respect to the wall of the tube.

2. A method (60) according to claim 1, wherein, during the sealing step (63), a capping machine (80) is used, configured so that the magnetic induction flux is higher with respect to the inner wall of the mouth of the tube (21) than with respect to the outer wall of the mouth of the tube.

3. A method (60) according to any one of claims 1 or 2, wherein, during the sealing step (63), a sealing punch (81) is used and put under pressure on the lid (25), and, once the magnetic induction has ended, the punch is kept under pressure on the lid.

4. Method (60) according to claim 3, wherein, during the sealing step (63), the cooling of the punch (81) is done by injecting air through a channel (82) of the punch used for suction of the operculum (25) before its placement on the mouth of the tube (21).

5. Method (60) according to any one of claims 1 to 4, wherein, during the step (61) of manufacturing the tube (21), the mouth of the tube is molded in an annular groove (59) of a stripper (48).

6. Method (60) according to any one of claims 1 to 5, wherein the lid (25) is made of metal co-extruded with a layer of the same plastic material as the tube.

7. Method (60) according to claim 6, wherein said metal is aluminium and said plastic material is polypropylene.

8. A method (60) according to any one of claims 1 to 7, wherein the tube (21) manufacturing step (61) comprises a molding step of the tube (21) in a mold, during which suction holding a barrier label (24) in position in the mold is carried out by means of at least one annular suction channel (43, 46) of a stripper (48), annular channel being in a plane perpendicular to the axis (27) of rotational symmetry of the outer wall of the mold.

9. Method (60) according to claim 8, wherein, during the molding step (61) of the tube (21), at least two annular suction channels (43, 46) are used, positioned near the ends of the tube (21) to be molded.

10. A method (60) according to any one of claims 8 or 9, wherein, during the molding step (61) of the tube (21), the annular channels (43, 46) are formed in an intercalary manner between a bezel (42, 45) and a die (44), each bezel being movable relative to the die, between a position away from the die, implemented during a step of introducing the label (24) into the mold (41 to 46) and a position closer to the die, implemented during the injection into the mold of the molten plastic material.

11. Method (60) according to claim 10, wherein, during the step (61) of molding the tube (21), a stripper (48) is used, the movement of the stripper causing the glasses (42, 45) and the die (44) to come together.

12. A method (60) according to any one of claims 8 to 11, wherein, during the step (61) of molding the tube (21), the mouth of the tube is molded in an annular groove (59) of a stripper (48).

13. Container (20) of food or pharmaceutical liquid (22) obtained by the process according to any one of claims 1 to 12 and comprising: - a tube (21) of geometrically defined plastic material, at least at its mouth, for the outside of the tube, by generatrices of a cylinder or a cone called "external" and, for the inside of the tube, by generatrices of a cylinder or a cone called "internal", this tube having a longitudinal axis (27) of rotational symmetry, this tube containing said liquid, and - a lid (25) welded onto the mouth of the tube, this lid extending, towards the outside of the tube, beyond said external generatrices;the welding of this operculum onto the tube comprising a meniscus (34) on the inner wall of the tube inside the volume defined by the internal generators, the volume of this meniscus being at least twice greater than the volume of any meniscus on the outer wall of the tube outside the volume defined by the external generators.;

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