EP2259906A1

EP2259906A1 - Method for making a flexible pouch

Info

Publication number: EP2259906A1
Application number: EP09720223A
Authority: EP
Inventors: Jean-Paul Naef
Original assignee: Compagnie Europeenne dEtude et de Recherche de Dispositifs pour lImplantation par Laparoscopie SA
Current assignee: Compagnie Europeenne dEtude et de Recherche de Dispositifs pour lImplantation par Laparoscopie SA
Priority date: 2008-02-28
Filing date: 2009-02-27
Publication date: 2010-12-15
Also published as: FR2928099A1; WO2009112787A1; US20110042864A1

Abstract

The invention relates to a method for making a flexible pouch, said method being characterised in that it comprises: the step of inserting (a) at least one fluid or powdery material into a hollow mould (3) having an inner wall (3A), said inner wall (3A) defining a closed moulding surface; the step of rotating (b) the mould (3) in order to spread the material substantially against the entire inner wall (3A) of the mould (3) by centrifuging. The invention can be used for flexible containers.

Description

METHOD FOR MANUFACTURING A FLEXIBLE POCKET

TECHNICAL AREA

The present invention relates to the general technical field of the manufacture of containers that can be used in particular in the medical or food industry to contain for example a food or a fluid.

The present invention relates in particular to the manufacture of flexible containers, which can for example be deformed during the application of a constraint.

The present invention relates to a method of manufacturing a flexible pouch.

PRIOR ART

In the treatment of morbid obesity in humans, it is known to insert an intragastric balloon in the stomach of a patient to occupy the internal volume of the stomach to restrict the space available for ingested food.

This intragastric balloon is generally introduced into the stomach in folded form and deflated by the natural routes of man, that is to say by the mouth and then the esophagus. After introducing the balloon into the stomach, the surgeon injects an inflation fluid to inflate the balloon to an effective functional volume for the treatment of the patient. The swelling of the intragastric balloon makes it possible to reduce significantly the flow of food ingested in the stomach in such a way that the patient reaches a feeling of satiety quickly enough and thus limits its food intake

The balloon is often composed of a flexible bag made of an elastomeric material compatible with the human body and / or animal and in particular with the stomach medium. The flexible bag of the intragastric balloon is intended to receive the inflation fluid, for example air, which allows it to pass from a deflated configuration to a functional inflated configuration. Thus, it is appropriate that the flexible bag is of sufficiently expandable nature to allow its passage from a deflated folded position to a stretched inflated position.

In general, the flexible pouch is made of biocompatible elastomer, for example silicone or polyurethane.

There are several known methods for manufacturing the flexible bag of the intragastric balloon.

One of these methods is the soaking technique which consists in dipping a core, having a determined shape corresponding to that desired for the balloon (for example sphere, ovoid, ellipsoid), in a bath of silicone dispersed in a solvent. This technique then involves a step of drying the film formed on the surface of the core by soaking, then a demolding step of the core to obtain a flexible silicone bag.

Such a manufacturing method, if it gives satisfaction, nevertheless has many disadvantages. Indeed, this process involves the use of a particularly toxic solvent whose handling imposes a large number of precautions for both the operator but also for equipment and the environment.

In addition, the soaking process requires special skills and must be carried out by specialized and qualified operators. Indeed, this process requires monitoring and a constant supply of solvent, especially for the management of the fluidity of the soaking bath. Thus, it is a particularly delicate process to implement.

In addition, the dipping process often involves several dipping steps to obtain the desired thickness for the pocket. This particularity of the process tends to increase its implementation, especially since the operator must wait for the complete evaporation of the solvent between each step to ensure the crosslinking of the deposited layer. Thus, the dipping process is particularly long and it usually takes half a day to obtain an intragastric balloon. In addition, the use of a multilayer coating for the formation of the balloon pocket can also lead to a lack of cohesion between certain layers, this lack of cohesion can have significant consequences on the unit of the balloon and its use in the patient's stomach.

In addition, the dipping method does not allow to control and effectively control the thickness of the flexible bag. Indeed, this process can lead to specific extra thicknesses that can weigh down the balloon and increase its cost of production. On the contrary, such a method can also cause thin zones which can weaken the balloon during its use. It is also known to provide a flexible pouch using a high frequency welding process, for example for the manufacture of a flexible pouch polyurethane. In this method, the flexible pouch is formed by joining superimposed flexible polyurethane sheets and attached together along a high frequency welding line at their interface.

This technique has the advantage of ensuring the obtaining of a flexible pouch of smaller thickness compared to the soaking process. This process is also easy to implement and particularly inexpensive.

However, this method also has disadvantages, particularly as regards its implementation. Indeed, in the case where it is desired to perform a surface treatment of the flexible bag, the high frequency welding step generally requires a precise order of the process operations and in particular the implementation of the treatment after the high welding frequency.

Moreover, during inflation of the polyurethane bag, the latter is deformed and its thickness is no longer homogeneous over its entire surface. Indeed, the swelling of the pocket, to obtain its functional form in the stomach, leads to a small wall thickness in some places, which can create areas of weakness and have negative consequences for both the balloon and for the patient.

SUMMARY OF THE INVENTION

The objects assigned to the invention therefore aim to remedy the various disadvantages listed above and to propose a new method of manufacturing a flexible pouch easy to implement, fast and economical.

Another object of the invention is to provide a novel method of manufacturing a flexible pouch for obtaining a flexible pouch of conventional form.

Another object of the invention is to provide a novel method of manufacturing a flexible pouch to obtain a flexible pouch designed with a known material, available and exploitable by conventional methods.

Another object of the invention is to provide a novel method of manufacturing a flexible pouch for obtaining a flexible pouch designed with a material to ensure the flexibility and strength of the flexible pouch.

Another object of the invention is to propose a novel method of manufacturing a flexible pouch involving manufacturing operations that are easy and quick to implement.

Another object of the invention is to propose a novel method of manufacturing a flexible pouch using conventional and environmentally friendly operations.

Another object of the invention is to provide a novel method of manufacturing a flexible pouch for obtaining a flexible flexible pouch whose thickness is particularly thin and homogeneous. Another object of the invention is to propose a new method of manufacturing a flexible pouch for obtaining a flexible bag used for the treatment of morbid obesity in humans.

Another object of the invention is to propose a new device for manufacturing a flexible pouch of particularly simple design, economical and easy to implement.

Another object of the invention is to provide a new device for manufacturing a flexible pouch for the manufacture of a flexible pouch of conventional shape and easy to use.

Another object of the invention is to provide a new device for manufacturing a flexible pouch for rapid manufacturing, economical and environmentally friendly.

Another object of the invention is to provide a novel device for manufacturing a flexible pouch for obtaining a flexible pouch of small thickness and resistant to mechanical stresses.

Another object of the invention is to propose a new flexible pouch of simple and economical design.

The objects assigned to the invention are achieved by means of a method of manufacturing a flexible bag, said method being characterized in that it comprises:

a step of introducing (a) at least one fluid or powder material into a hollow mold comprising an inner wall, said inner wall defining a closed molding surface, - A step of rotating (b) the mold for spreading said material against substantially the entire inner wall of the mold by centrifugation.

The objects assigned to the invention are also achieved by means of a device for manufacturing a flexible bag, said device being characterized in that it comprises:

a hollow mold comprising an inner wall, said inner wall defining a closed molding surface, said mold being intended to receive at least one fluid or powder material, means for rotating the mold to spread said material against substantially all the inner wall of the mold by centrifugation.

The objects assigned to the invention are further achieved by means of a flexible pouch characterized in that it comprises a one-piece structure and a thickness substantially less than 500 microns.

SUMMARY DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the invention will appear better on reading the description which follows, as well as with the aid of the accompanying drawings, given purely by way of illustration and without limitation, in which:

- Figure 1 illustrates, in a schematic perspective view partially exploded, a preferred embodiment of a device for manufacturing a flexible bag according to the invention. - Figure 2 illustrates, in a schematic cross-sectional view, a preferred embodiment of a flexible bag according to the invention.

BEST MODE OF REALIZING THE INVENTION

The invention relates to a method of manufacturing a flexible bag 1 having in particular elastic properties allowing it to deform without deteriorating when subjected to stress, particularly to mechanical stresses.

The present invention relates to any type of flexible pouch, usable in various fields such as, for example, the food industry for the packaging and / or the packaging of foodstuffs or the medical field for the insertion of the flexible pouch into implantable devices.

The method of manufacturing said flexible bag 1 comprises a step of introducing (a) at least one fluid or powder material into a hollow mold 3 comprising an inner wall 3A, said inner wall 3A defining a closed molding surface. Advantageously, the mold 3 of the present invention has at least one axis of symmetry, and preferably at least two axes of symmetry, advantageously substantially perpendicular to each other. Preferably, the mold 3 has a substantially spherical shape. In other words, the mold 3 for receiving the material is substantially identical in shape to that of a hollow sphere. Advantageously, the mold 3 has an inside diameter of between substantially 1 and 20 cm, preferably between substantially 5 and 12 cm.

As illustrated in Figure 1, the mold 3 comprises at least two shells 4 and 5 of substantially identical and hemispherical shape, said at least two shells 4, 5 being intended to be assembled to form the mold 3 of spherical shape and define a molding chamber 6. The two shells preferably have a substantially identical half-sphere shape and are arranged opposite each other, so as to allow their precise assembly. They are held facing each other without touching each other. The material is then poured into the mold 3, precisely in at least one of the two shells 4, 5, which is preferably in a horizontal position (FIG. 1 represents a vertical position of the two shells 4, 5) in order to avoid the flow of material out of the mold 3.

Advantageously, in step (a), there is introduced a quantity, preferably precise and previously calculated, of material in fluid or powder form, ie preferably in liquid, viscous or solid form, as for example under form of granules or powder. The material of step (a) comprises at least one polymeric material, and preferably an elastomeric material, that is to say a material capable of undergoing large deformations in a reversible manner.

Preferably, the material of step (a) comprises at least one polyurethane. It may be for example a polyurethane in liquid form composed of isocyanate and polyol or a thermoplastic polyurethane in the form of granules, said granules being intended to be liquefied in the presence of heat.

The material may also preferably comprise at least one thermoplastic, that is to say a plastic intended to deform or even to be fluidized in the presence of heat. It can be envisaged for example to use polyethylene (PET), polyvinyl chloride (PVC) including PVC plastisol.

It is also conceivable, without departing from the scope of this invention, that the material of step (a) comprises a mixture of several materials, advantageously chosen from those previously described. For example, the mixture may comprise granules of a polyurethane and a PVC.

Preferably, the material of the introduction step may comprise at least one silicone.

After the introduction of the material into the mold 3, the manufacturing method preferably comprises an operation of implementing an air gap within said mold so that said at least two shells 4, 5 of the mold 3, previously brought together , assemble to form a closed mold 3. This operation is performed through the introduction of a needle, connected to a vacuum pump (not shown in the figures), in one of two septa 4A, 5A intended to be positioned at the poles of said shells. The septa 4A, 5A are preferably made of silicone. Thanks to the vacuum pump, the air vacuum is produced in the molding chamber 6, in which the pressure reaches a value substantially between 1 and 20 mbar, and preferably substantially equal to 10 mbar. The realization of the vacuum of air thus causes the assembly of the two shells 4, 5.

Preferably, the mold 3 comprises a seal 7 allowing the substantially sealed closure of the mold 3 to the material it contains. The seal 7 is advantageously positioned on at least one of the two shells 4, 5 at the contact zone between the two shells 4, 5 during their assembly, so as to ensure a tight closure of the mold 3.

The method comprises, after the step of introducing (a) the material and the vacuum closing operation of the mold 3, a step of rotating (b) the mold 3 to spread said material against substantially the entire inner wall 3A of the mold 3 by centrifugation.

Preferably, the spinning step comprises an operation for supplying a flow of fluid at a first drive means 8 disposed at the periphery of said mold 3, in order to create a rotational movement by centrifugation. said mold 3 around a first axis of rotation X-X '. The first axis of rotation X-X 'as illustrated in Figure 1 preferably passes through the poles of the two shells 4, 5, precisely at their septa 4A, 5A.

The first drive means 8 preferably comprises pallets 8A positioned at the periphery of the mold 3. Advantageously, said pallets 8A are positioned all around the mold 3, substantially at the equatorial zone of said mold 3. In one embodiment of the first drive means 8, the pallets 8A are preferably arranged at the periphery of one of the two shells 4, 5.

Alternatively, it is conceivable that these pallets 8A are arranged on the two shells 4, 5, regularly or not at the periphery of said shells. Preferably, said mold 3 comprises two series of pallets positioned over the entire perimeter of said shells 4, 5 at the equatorial zone at the periphery of the mold 3.

Preferably, a fluid flow is provided at the first drive means 8, that is to say at the level of the pallets 8A. For the purposes of the invention, the fluid is a gas or a liquid, preferably under pressure so as to provide sufficient power to rotate the 3. Advantageously, a compressed air stream is provided on the pallets 8A with the aid of an air-sending system 8B.

Advantageously, the step (b) of rotation also comprises an operation of rotating said mold 3 around a second axis of rotation YY ', substantially perpendicular to the first axis X-X', the speed of rotation of the mold 3 around the axis YY 'being substantially synchronized with the speed of rotation of the mold around the axis X-X'. This manufacturing method in fact implements a second rotational movement of the mold 3 around the Y-axis Y ', as illustrated in Figure 1. The rotation of the mold 3 around the axis YY' is advantageously by a second drive means 10, preferably by an electric motor 10A. The mold 3 is thus simultaneously subjected to a first rotational movement about the axis X-X 'and to a second rotational movement about the axis YY'.

The rotation as described above makes it possible to apply the centrifugal force to the material introduced into the mold 3. In fact, the compressed air and the motor make it possible to provide a power such that the rotation of the mold 3 is by centrifugation and achieves a rotation speed of between 1000 and 5000 revolutions per minute and preferably substantially equal to 3000 revolutions per minute. The speed of rotation of the mold 3 around the Y-axis Y 'is synchronized with that of the mold around the X-X' axis so that the rotational speeds are identical.

Rotating the mold 3 by centrifugation allows the material to be spread against substantially the entire inner wall 3A of the mold 3. In other words, the application of the centrifugal force, along two perpendicular axes of rotation, to said material causes spreading over the entire molding surface of the molding chamber 6, thanks in particular to at the creation of a bearing force which plates said material against the inner wall 3A of the mold 3 and determines the thickness of the pocket obtained. In addition, this method makes it possible to obtain a spread of uniform and thin thickness over the entire surface of the inner wall 3A of the mold 3. This is particularly advantageous for obtaining a pocket of uniform and uniform thickness. , showing no difference in thickness, so no area of fragility and / or rigidity too important. The implementation of the centrifugation during this manufacturing process also makes it possible advantageously to eliminate any bubble of air or gas that may be present in the material. Centrifugation thus contributes to a "degassing" of the material effective for homogenization

Advantageously, the spinning step (b) comprises a substep of heating (b-i) of the material contained in said mold 3 in order to fluidify said material. While the material contained in the mold 3 is subjected to the centrifugal force, said mold 3 is heated so that the material becomes fluid, preferably in liquid form.

Preferably, the sub-step (bi) comprises an operation of heating the mold 3 by providing a heated fluid to reach a temperature of the material substantially between 100 and 300 ⁰ C, preferably substantially between 150 and 220 ⁰ C. Advantageously, introducing hot air into the compressed air stream used for rotating the mold 3 about the axis XX ', so as to heat the mold 3 and to thin the material . It is of course conceivable to use another heating method, such as for example by supplying hot water vapor or a hot liquid. Preferably, the mold 3 is composed of a heat resistant material, preferably aluminum. An aluminum mold 3 is particularly resistant to heat when introducing hot compressed air. Alternatively, it is also possible to use a process of heating the mold by electromagnetic induction which also makes it possible to reach a temperature of the material substantially between 100 and 300 ⁰ C, preferably substantially between 150 and 220 ⁰ C. This method consists in subjecting said mold 3 in rotation to an electromagnetic field. The mold 3 bypasses the electromagnetic field so as to cause heating of the material constituting the mold 3 and thus the fluidification of the material it contains. Advantageously, said mold 3 is composed of a material resistant to electromagnetic flux, preferably steel.

Advantageously, the inner wall 3A of the mold 3 is substantially smooth without any surface roughness and substantially mirror-polished appearance. Such an inner wall 3A, preferably obtained with steel, makes it possible to obtain a perfectly smooth flexible pouch 1 without any surface defects. This feature is particularly interesting in the case where the flexible pouch undergoes a surface treatment subsequent to its manufacture, including a covering with a material, such as metal or a ceramic. A smooth outer surface 1 B of the flexible pouch 1 facilitates the hooking and holding of a coating material, in particular a metal.

The step of heating (b-i) of the material is preferably necessary when introducing into the mold a solid material, in the form of granules or powder, for example, or for thinning viscous materials. On the other hand, this step (b-i) may not be necessary for certain materials brought in liquid form.

After this fluidification step of the material, which is preferably done at the same time as the rotation of the mold 3, the step of rotating (b) furthermore advantageously comprises a sub-step of solidification (b ₂ ) of the material in the form of a flexible bag conforming to the inner wall 3A of the mold 3, the said solidification substep (b ₂ ) comprising a cooling operation of the mold 3. Once the material spreads homogeneously over the entire inner surface 3A of the mold 3, the material is solidified to obtain a flexible pouch 1 in one piece.

Preferably, the solidification step (b ₂ ) consists of a rapid cooling of the mold 3 which allows to cool rapidly also the material it contains and freeze the latter in the form of a flexible bag 1. The cooling is advantageously performed by an expansion of ice-cold gas, preferably in the form of ice-cold compressed air whose temperature is substantially below 0 ^° C., advantageously substantially between -20 ^° C. and -30 ° C.

Alternatively, other cooling means can be envisaged:

a gas expansion in the liquid phase, for example liquid nitrogen at a negative temperature,

a liquid expansion with, for example, cold water or at ambient temperature, a relaxation of a liquid in the air.

Preferably, the speed of cooling of the flexible bag 1 depends on the nature of the material constituting said bag and also the desired use of said bag. Thus, the cooling can vary between a slow speed of realization at ambient temperature and a very fast speed by thermal shock. After the solidification substep (b ₂ ), the manufacturing method comprises an operation of stopping the rotation of the mold 3.

Finally, after step (b ₂ ) solidification and stopping rotation, the manufacturing process of the flexible bag 1 preferably comprises a demolding step (c) of the flexible bag 1 in which is extracted the flexible bag 1 of the mold 3, said demolding step (c) comprising an operation for introducing a fluid between the flexible bag 1 and the inner wall 3A of the mold 3, in order to facilitate the extraction of said bag 1. Advantageously, the mold of the flexible bag is made in a simple manner without adding a release agent or any additive pollutant. This fluid supply step is particularly rapid and preserves the characteristics of the flexible bag 1, in particular without deterioration of the surface state of said flexible bag 1.

At the end of the demolding step, a flexible pouch 1 can thus be obtained which can be used for the previously described applications. Said flexible pouch 1 has the advantage of being particularly thin. Indeed, its thickness is advantageously substantially less than 500 microns, preferably substantially less than 200 microns, and is constituted in a single block, that is to say in one piece and without any opening. This process of centrifugation of an elastomer in a closed spherical mold therefore makes it possible to obtain a thin, one-piece flexible pouch, such a flexible pouch being particularly advantageous for medical applications, in particular in the field of the treatment of the morbid obesity for which it is necessary to have a soft and thin pocket.

Preferably, the flexible bag 1 obtained with the previously described method is designed to form or to be inserted in a device implantable, said device being intended to be implanted in a human body and / or animal. Advantageously, said flexible pouch 1 is intended to contain an inflation fluid and to form or to be inserted into an implantable device in the human body and / or animal. Within the meaning of the invention, an inflation fluid is composed of a liquid or a gas which is injected into the flexible bag 1, precisely in its internal cavity 2, to allow the passage of the flexible bag 1 of a configuration deflated to a stretched inflated configuration, of substantially spherical shape.

In a preferred embodiment of the invention, the flexible pouch 1 is intended to contain an inflation fluid and to form or to be inserted into an intragastric balloon, said balloon being intended to be implanted in the stomach of a patient to reduce the volume of said stomach as part of a treatment of morbid obesity. The flexible pouch 1 comprises an inner face 1A in contact with the inflation fluid and an outer face 1B intended to be in contact with the body fluid, preferably with the stomach medium. For such use, the flexible pouch 1 preferably has a diameter substantially between 5 and 12 cm and is obtained using the method described above.

Advantageously, the flexible pouch 1 forming the balloon or the balloon comprising said flexible pouch 1 is introduced in a folded deflated form, preferably by natural means (mouth and esophagus), in the stomach of a patient suffering from obesity, in order to reduce the space available for food ingested by the patient and thus to help with weight loss.

It is of course conceivable that the flexible bag 1 is used for any other application. Independently of all the above, the present invention relates to a flexible pouch comprising a one-piece structure and a thickness substantially less than 500 microns. Preferably, the thickness of said pocket is substantially less than 200 microns.

The present invention also relates to a device for manufacturing a flexible bag 1. This device as illustrated in Figure 1 comprises a hollow mold 3 comprising an inner wall 3A, said inner wall 3A defining a closed molding surface, said mold 3 being intended to receive at least one fluid or powder material. The mold 3 and the material are substantially identical to those described in the foregoing. Thus, preferably, the hollow mold 3 comprises at least one axis of symmetry, preferably two axes of symmetry. It is advantageously of substantially spherical shape and comprises at least two shells 4, 5 of substantially identical and hemispherical shape. The mold 3 advantageously comprises a diameter substantially between 1 and 20 cm, preferably substantially between 5 and 12 cm.

Preferably, the manufacturing device of the present invention comprises a closing means (not shown) of the mold 3 comprising a pump designed to produce an air vacuum in said mold 3 so as to allow assembly of said at least two shells. A needle is inserted at one of the septa 4A, 5A of the shells 4, 5 and is connected to a pump for evacuating the air from the molding chamber 6 and thus closing the mold 3.

The device also comprises means for rotating the mold 3 to spread said material against substantially the entire inner wall 3A of the mold by centrifugation. Preferably, the rotating means 11 makes it possible to keep the mold 3 in a stable position, in particular using a fork 11A for holding the two shells 4, 5 of the mold 3 when it is stationary or in rotation. Indeed, the septa 4A, 5A of said shells 4, 5 are fixed on the fork 11A in a mobile manner so as to allow the movement of the mold 3 in rotation by centrifugation and to allow manipulation by an operator, for example to remove one of said shells 4, 5. The septa 4A, 5A are preferably made of silicone and has a diameter substantially between 5 and 20 mm, preferably substantially equal to 12 mm.

Advantageously, the rotating means 11 also comprises the first drive means 8, preferably pallets 8A, positioned at the periphery of the mold 3, for driving said mold 3 in rotation when it is subjected to a flow of fluid . The first drive means 8 comprises in particular an air sending system 8B which allows the supply of compressed air on the pallets 8A to cause them to rotate.

Preferably, the rotating means 11 comprises a second drive means 10 for rotating said mold 3 about an axis YY ', said axis YY' being substantially perpendicular to the axis of rotation XX ' of the mold 3 driven by the first drive means 8. Advantageously, the second drive means 10 comprises a motor, preferably an electric motor 10A, as illustrated in FIG.

The rotation means 11 further comprises a connection 9 between the fork 11A and the motor 10A, making it possible to connect the whole of the rotation means 11. The rotating means 11 thus constitutes a holding means for to fix both said drive means 8, 10 and the mold 3. According to a preferred embodiment, the rotation means 11 finally comprises a servo-control means 12 of the speed of the mold around the axis YY 'with respect to the speed of said mold 3 around the axis X-X . This servo-control means 12 makes it possible in particular to synchronize the speed of the mold 3 around the axis YY 'with respect to that of the same mold 3 around the axis X-X'.

In order to obtain a pocket 1 of uniform thickness, it is necessary to maintain the speeds around the two substantially identical axes. To do this, a first sensor 12A is used positioned at the periphery of the mold 3. At each rotation of the mold 3 around the axis X-X ', the first sensor 12A, preferably a magnet, passes a sensor 12B connected to an electronic calculator which allows to precisely slave the speed around the axis YY 'relative to that around the axis X-X'. The servo means 12 thus makes it possible to control the speed of rotation about the Y-Y 'axis and to synchronize the two speeds. This has the advantage of having a rotational speed of the mold 3 homogeneous and identical around each of the axes of rotation X-X 'and Y-Y'. Alternatively, any other device for synchronizing speeds can be envisaged, particularly through the implementation of sensors of electrical, magnetic, light, optical nature, this list is not exhaustive.

Advantageously, the means for rotating said mold 3 is designed to impart to the mold a speed of rotation of between 1000 and 5000 rpm, preferably between 2000 and 4000 rpm, preferably substantially equal to at 3,000 rpm. Such a speed causes the application of the centrifugal force on the material contained in the mold 3 and causes its smooth homogenous spread over the entire surface of the inner wall 3A of the mold 3. The device of the present invention allows the implementation of a centrifugation process around two perpendicular axes in a closed spherical mold so as to obtain a flexible pouch having a small thickness, substantially less than 500 microns, and homogeneous.

POSSIBILITY OF INDUSTRIAL APPLICATION

The invention finds its industrial application in the design and manufacture of flexible containers, especially in the medical or food industry.

Claims

- A method of manufacturing a flexible pouch (1), said method being characterized in that it comprises:

a step of introducing (a) at least one fluid or powder material into a hollow mold (3) comprising an inner wall (3A), said inner wall (3A) defining a closed molding surface,

- A step of rotating (b) the mold (3) for spreading said material against substantially the entire inner wall (3A) of the mold (3) by centrifugation.

- Method according to claim 1 characterized in that the mold (3) has at least one axis of symmetry, and preferably at least two axes of symmetry.

- Method according to claim 1 or 2 characterized in that the mold (3) has a substantially spherical shape.

- Process according to claim 1 characterized in that the material of step (a) comprises at least one polymeric material, and preferably an elastomeric material.

- Process according to claim 4 characterized in that the material of step (a) comprises at least one polyurethane.

- Method according to claim 4 characterized in that the material of step (a) comprises at least one silicone. 7 - Method according to one of the preceding claims characterized in that the mold (3) comprises at least two shells (4, 5) of substantially identical shape and hemispherical, said at least two shells (4, 5) being intended to be assembled to form a mold (3) of spherical shape.

8 - Process according to claim 7 characterized in that it comprises an operation of implementation of an air gap within said mold (3) so that said at least two shells (4, 5) of the mold (3 ) are assembled to form a closed mold (3).

9 - Method according to one of the preceding claims characterized in that the step of rotating (b) comprises an operation of supplying a fluid flow at a first drive means (8) disposed at the periphery of said mold (3), in order to create a rotational movement by centrifugation of said mold (3) around a first axis of rotation X-X '.

10 - Process according to claim 9 characterized in that step (b) comprises an operation of rotating said mold (3) about a second axis of rotation YY ', substantially perpendicular to the first axis X-X ', the speed of rotation of the mold (3) around the axis YY' being substantially synchronized with the speed of rotation of the mold (3) around the axis X-X '.

11 - Method according to one of the preceding claims characterized in that step (b) comprises a substep of heating (bi) of the material contained in said mold (3) in order to fluidify said material. - Method according to claim 11 characterized in that the sub-step (bi) comprises a heating operation of the mold (3) by providing a heated fluid to achieve a temperature of the material substantially between 100 and 300 ⁰ C , preferably substantially between 150 and 220 ^° C.

- Method according to one of claims 1 to 12 characterized in that step (b) comprises a substep of solidification (b ₂ ) of the material in the form of a flexible bag (1) conforming to the inner wall ( 3A) of the mold (3), said solidification substep (b ₂₎ comprising a mold cooling step (3).

- Method according to one of claims 1 to 13 characterized in that it comprises a demolding step (c) of the flexible bag (1) during which the flexible pouch (1) of the mold (3), said step of demolding (c) comprising an operation of introducing a fluid between the flexible bag (1) and the inner wall (3A) of the mold (3), to facilitate the extraction of said pocket (1).

- Device for manufacturing a flexible bag (1), said device being characterized in that it comprises:

- a hollow mold (3) comprising an inner wall (3A), said inner wall (3A) defining a closed molding surface, said mold (3) being intended to receive at least one fluid or powder material,

- A means for rotating (11) the mold (3) for spreading said material against substantially the entire inner wall (3A) of the mold (3) by centrifugation. - Manufacturing device according to claim 15 characterized in that the hollow mold (3) comprises at least one axis of symmetry, preferably two axes of symmetry.

- Manufacturing device according to claim 15 or 16 characterized in that the mold (3) is substantially spherical shape.

- Manufacturing device according to one of claims 15 to 17 characterized in that the mold (3) comprises at least two shells (4, 5) of substantially identical shape and hemispherical.

- Manufacturing device according to claim 18 characterized in that it comprises a closure means of the mold (3) comprising a pump designed to produce an air vacuum in said mold (3) so as to allow assembly of said at least two shells (4, 5).

- Manufacturing device according to one of claims 15 to 19 characterized in that the rotating means (11) comprises a first drive means (8) positioned at the periphery of the mold (3) for driving said mold ( 3) in rotation when subjected to a flow of fluid.

- Manufacturing device according to claim 20 characterized in that the rotating means (11) comprises a second drive means (10) for rotating said mold about an axis YY ', said axis YY being substantially perpendicular to the axis of rotation XX 'of the mold (3) driven by the first drive means (8). - Manufacturing device according to claim 21 characterized in that the rotating means (11) comprises a servo means (12) of the speed of the mold (3) around the axis YY 'with respect to the speed said mold (3) around the axis X-X '.

- Manufacturing device according to one of claims 15 to 22 characterized in that the means for rotating (11) said mold (3) is designed to impart to the mold (3) a rotational speed of between 1000 and 5 000 revolutions per minute, preferably between 2000 and 4000 revolutions per minute, even more preferably substantially equal to 3000 revolutions per minute.