Method for producing at least one flexible plastic container

Abstract

The invention relates to a method for the manufacture of at least one flexible plastic container, according to which method each container (10) comprises two separate walls (12, 13) facing one another joined at their circumference by a sealed peripheral edge (14), said separate walls defining a storage space of the container (10). According to the invention, at least the following stages are realized: a) Forming a pile of two sheets (26, 27) of plastic material, said sheets (26, 27) being laid one against the other, the surfaces which face one another of these sheets (26, 27) being placed directly in contact with one another without any element acting as an interface, b) Simultaneously shaping said sheets (26, 27) thus laid one against the other in order to define said at least one container (10) without having previously separated these sheets, at least each container (10) being partially formed, said sheets (26, 27) being maintained lying one against the other in at least one section of the areas of said sheets (26, 27) intended to constitute said peripheral edge (14) of each container (10) during this shaping and c) Sealing at least partially the areas of said sheets (26, 27) intended to constitute said peripheral edge (14) of at least each container (10).

Claims

1. A method for the manufacture of at least one flexible plastic container, each container comprising two separate walls facing one another joined at least on a section of their circumference by a sealed peripheral edge, said separate walls defining a storage space of the container, wherein at least the following stages are realized: a) forming a pile of two sheets of plastic material, said sheets being laid one against the other, the surfaces which face one another of these sheets being placed directly in contact with one another without any element acting as an interface, b) simultaneously shaping said sheets thus laid one against the other in order to define said at least one container without having previously separated these sheets, where simultaneously shaping said sheets comprises, with at least each container being partially formed, said sheets being maintained lying one against the other in at least one section of the areas of said sheets intended to constitute said peripheral edge of each container during this shaping, said shaping being realized by suction pressure forming by placing said pile between two mold sections which can be spaced at a distance from one another and brought to bear one against the other thus defining one or more cavities, at least one of these cavities thus formed corresponding to the shape and the external dimensions of a container to be manufactured, said at least one cavity then being closed at a section of its periphery corresponding to a section of the peripheral edge of the corresponding container to be formed, at least one of said mold sections comprising several orifices linked to one or more pump units, c) sealing at least partially the areas of said sheets intended to constitute said peripheral edge of at least each container.

2. The method according to claim 1, wherein an additional stage is realized which consists for each container of inserting between said sheets at least one element for accessing its storage space permitting fluid communication between this storage space and the exterior.

3. The method according to claim 1, wherein the areas of said sheets intended to constitute said peripheral edge of each container are at least partially sealed before realizing stage b.

4. The method according to claim 1, wherein in stage b, also by shaping of said sheets there is definition of a slot for each element for accessing the storage space of the container or containers, each slot being configured to receive the corresponding access element.

5. The method according to claim 1, wherein in stage b, also by shaping of said sheets there is definition of at least one closed elongation, called an access element, of said container or of at least some of said containers, each closed elongation defining a reception space having fluid communication with said storage space of the corresponding container.

6. The method according to claim 1, wherein in stage b, also by shaping of said sheets there is definition of at least one conduit or bridging link connected to a peripheral edge of at least one container to permit the filling thereof, said conduit defining an internal channel having fluid communication with the storage space of said at least one container.

7. The method according to claim 6, wherein having filled said container or containers, there is sealing of the remainder of the sheets separated at said peripheral edge of each container so as to close each container.

8. The method according to claim 1, wherein in stage b, said sheets are also maintained lying one against the other in at least one distinct area of said peripheral edge of one or more containers to divide the internal space of the corresponding container or containers.

9. The method according to claim 1, wherein in stage b, there is simultaneous shaping of said two sheets to make at least one flexible container without separating said sheets during this shaping.

10. The method according to claim 9, wherein after stage c, said sheets are separated at the at least one container by means of the introduction of the sole biological material intended to be contained in this container so as to limit its contamination or by circulation of a controlled gaseous fluid.

11. The method according to claim 1, wherein after stage b and before stage c, an additional stage is realized consisting of cooling said at least one container.

12. The method according to claim 1, wherein throughout at least said stages a to c, the environment in which said pile of two sheets is placed is controlled so as to limit the presence of bioburden and of particles capable of transporting this bioburden.

13. The method according to claim 12, wherein at the device or the machine permitting realization of stage b, an air flow is circulated from top to bottom to push towards the ground the particles or bioburden present in the atmosphere around said device.

14. The method according to claim 1, wherein deionization of said pile is realized in order to get rid of electrostatic charges.

15. The method according to claim 1, wherein said sheets are produced from a single film of plastic material or from different films of plastic material, said film or said films having a surface roughness and a thickness such that the adhesion strength of the sheets of said pile prevents any untimely adhesive failure of said sheets.

16. The method according to claim 1, wherein prior to stage a, a continuous film is formed by melt extrusion of a plastic material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other particular advantages, objectives and characteristics of the present invention will become apparent from the following description, which is provided by way of an explanation and is by no means exhaustive, of the attached drawings, in which:

(2) FIG. 1 is a top view of a container/bridging link assembly produced according to a first embodiment of the invention, this assembly not yet having been separated from the sheets which permitted its production,

(3) FIG. 2 shows a front view of the assembly of FIG. 1,

(4) FIG. 3 is a perspective view of a shaping apparatus used for the manufacture of the assembly of FIG. 1 according to a particular embodiment of the invention,

(5) FIG. 4 is a diagrammatic representation of the pile of sheets laid one against the other used to produce the container/bridging link assembly of FIG. 1,

(6) FIG. 5 is a partial and enlarged view of the pile of FIG. 4 after shaping, which shows the slot intended to receive a connection element,

(7) FIG. 6 is a partial and enlarged view of the pile of FIG. 5 after insertion of a connection element into said slot and sealing of this connection element in its slot,

(8) FIG. 7 is a perspective view of a container according to a second embodiment of the present invention, this container comprising multiple storage chambers linked to one another and being housed in a protective case with a view to the cryopreservation of its contents,

(9) FIG. 8 is a perspective view of the container of FIG. 7 after its filling and separation of several storage chambers, one of these chambers being represented in the proximity of the container,

(10) FIG. 9 is a partial and enlarged view of a storage chamber of the container of FIG. 7,

(11) FIG. 10 is a partial and enlarged view of a storage chamber of the container of FIG. 7, the end of which has been cut to allow the taking of samples from the contents of the storage chamber.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

(12) Firstly, it is noted that the figures are not to scale.

(13) FIGS. 1 and 2 show an assembly comprising a three-dimensional flexible container 10 for the cryogenic storage of a biological substance and a tubular bridging link 11 which forms an integral component of this container such that this bridging link has fluid communication with the storage space of the container, this bridging link permitting linking of this assembly to a connection element (not represented) for the introduction of said biological substance according to a particular embodiment of the invention.

(14) This flexible container 10 comprises a first wall 12 and a second wall 13 made of a flexible film of plastic material suited to cryogenic storage placed facing one another and joined on their periphery by means of sealing. Purely for illustrative purposes, this plastic material is ethylene-vinyl acetate (EVA).

(15) The first wall 12 which is the mirror image of the second wall 13 comprises a peripheral edge area 14 which is flat or more or less flat, where these walls 12, 13 are sealed.

(16) It also comprises an area 15 delimiting one of the most external faces of the container 10, which is flat or more or less flat and parallel to said peripheral edge area 14 and is placed at a distance from the latter to define a first storage chamber.

(17) These areas 14, 15 are linked to one another by an edge area 16 which is flat or more or less flat and which is placed slantwise.

(18) This flexible container also comprises a connection element 17 extending through the seal joining the first and second walls 12, 13 for accessing its storage space for the purpose of filling it with and/or emptying it of a liquid biological substance. This storage space is here defined by the storage chambers of the first and second walls 12, 13.

(19) In order to produce this flexible container, firstly a continuous tubular film is formed by melt extrusion of a plastic material, which is cut laterally to obtain a pile of two sheets 26, 27 of plastic material (FIG. 4).

(20) These sheets 26, 27 are laid directly one against the other without any external element being introduced between these sheets. The surfaces which face one another of these sheets 26, 27 are directly contacting so as to prevent contaminants and germs from passing between the sheets.

(21) Advantageously, the adhesion strength of the sheets 26, 27 of the pile prevents any untimely adhesive failure of these sheets.

(22) At the exit of the extruder, a double wound film coil is formed.

(23) This coil is then uncoiled so as to reel out this pile of sheets 26, 27 at a sealing station.

(24) There, the sheets of this pile are directly joined in certain sections of the areas of the sheets intended to constitute the peripheral edge of the container 10 to be produced as well as those intended to constitute the lateral edges of the bridging link 11.

(25) That which has just been described for a vessel/bridging link assembly is of course repeated as many times as necessary to obtain the number of assemblies to be manufactured by reeling out the pile of sheets at this station.

(26) Nevertheless, the sheets of this pile are at no time separated one from the other before or during this sealing stage.

(27) For each assembly, the pile of sheets 26, 27 thus partially sealed and laid one against the other is then heated and placed between the two mold sections 18, 19 of an apparatus 20 for suction pressure forming. The heating stage prior to the shaping of the sheets of the pile is for example realized by exposing the pile to radiation. Alternatively, this heating stage may be realized by means of blowing of filtered hot air. This filtration allows provision of hot air which is free of particles and germs.

(28) The two mold sections 18, 19 can be spaced at a distance from one another and brought to bear one against the other thus defining a first cavity corresponding to the shape and the external dimensions of the container 10 to be manufactured as well as the shape and the dimensions of a slot intended to receive a connection element 17, and a second cavity communicating with the first cavity to define the bridging link 11.

(29) When the two mold sections 18, 19 are brought to bear one against the other, the cavities are closed at their periphery. The cavity permitting the partial creation of the flexible vessel is thus closed at its periphery corresponding to a section of the peripheral edge of the corresponding container to be formed and its periphery corresponding to the slot 28 for the connection element 17 to be formed.

(30) Advantageously, only one of the mold sections 18, 19 comprises these cavities which are linked by orifices to one or more pump units to generate the suction required for the shaping of the pile of sealed sheets.

(31) It is thereby ensured that the sheets 26, 27 of this pile are shaped simultaneously without separation, which significantly reduces the risk of any contamination. The separation of the thus-formed walls of the container in order to partially delimit the storage space is achieved subsequently when the thus-manufactured container is filled with the biological substance.

(32) For each assembly, a stage of cutting is realized which permits the releasing of this assembly. Advantageously, this slot 28 formed for receiving a connection element 17, is closed so as to prevent any introduction of contaminants during the cutting operation.

(33) Furthermore, once the films are sealed and cut, the creation of this slot 28 makes it possible to avoid separating the sheets of the pile in order to insert the connection element 17 and thereby cause an intake of particles and germs via the ambient air.

(34) Finally, the connection element 17 is sealed with the peripheral edge 29 of the flexible container to be manufactured (FIG. 6).

(35) A second embodiment of a container of the present invention shall be described below with reference to FIGS. 7 to 10. This container is housed in a metal protective case 30 for the purposes of its handling and its cryogenic storage.

(36) This container has an elongated shape, in this case rectangular, when viewed in a top view, defining a first longitudinal axis. This container comprises multiple storage chambers 31, in this case six (6), which are aligned with spacing at regular intervals from one another. The separation area 32 separating two successive storage chambers 31 has a line 33 of least resistance, or pre-cut strip, which advantageously allows easy separation of the storage chambers 31.

(37) Each storage chamber 31 has an elongated shape extending along a second longitudinal axis perpendicular to said first longitudinal axis.

(38) Two consecutive storage chambers 31 are also linked at their base or lower section by a section 34 of conduit which permits fluid communication between the storage spaces of these storage chambers 31.

(39) The container also comprises a flexible tube 35 placed on a lateral edge of the container and having fluid communication via each section 34 of conduit for fluid communication with the storage space of each of the storage chambers 31.

(40) This tube 35 which serves as an input port of the container permits easy introduction into each storage chamber 31 of the liquid medication, of the cells such as stem cells or of the blood, to be preserved by cryopreservation.

(41) Each individual storage chamber 31 has a three-dimensional shape to allow improved storage, this shape having a longitudinal dimension (here height) in a first direction defined by said second longitudinal axis, which is bigger than both the longitudinal dimension (here width) in a second direction defined by said first longitudinal axis and than the longitudinal dimension (here thickness) in a third direction perpendicular to the first direction and to the second direction.

(42) Thus each individual storage chamber 31 forms a projection on either side of a median plane 36 defined by the pile of sheets not shaped but joined to one another for example by sealing. The two sections of each storage chamber 31 placed facing one another forming a projection of this median plane 36 are symmetrical or form a mirror image of one another relative to this median plane.

(43) With the exception of its upper end, the body of each storage chamber thus comprises a back wall which is flat or more or less flat and a front wall which is flat or more or less flat, which are both placed in said third direction, at a distance from said median plane 36 and which are distinct from one another to define the storage space of the chamber. These front and back walls are linked at the peripheral edge of the storage chamber 31 extending in the median plane 36 by lateral walls which have a rounded or flat or more or less flat shape. In the latter case, these lateral walls can be placed slantwise.

(44) The upper end of each storage chamber comprises a sampling port 37 with a three-dimensional shape which is sterile and empty. This sampling port 37 is separated from the storage space of the corresponding storage chamber by a watertight connecting strip, obtained for example by sealing, created on a level with a funnel 38 of the storage chamber 31.

(45) As represented in FIG. 10, this sampling port 37 is configured to define a slot when it has been opened by means of a transverse cut, intended to receive a trocar (not represented) while ensuring the impermeability of its connection with the latter.