WO2008145858A2

WO2008145858A2 - Shaping method and corresponding device

Info

Publication number: WO2008145858A2
Application number: PCT/FR2008/000583
Authority: WO
Inventors: Jean-Paul Gilbert Ricol; Pascal Paganon
Original assignee: Compagnie Européenne D'etude Et De Recherche De Dispositifs Pour L'implantation Par Laparoscopie
Priority date: 2007-04-23
Filing date: 2008-04-23
Publication date: 2008-12-04
Also published as: WO2008145858A3; FR2915128A1; FR2915128B1

Abstract

The invention relates to a method for shaping a flexible sheet (1) made of an elastomer or a plastic material, that comprises: a positioning step during which said sheet (1) is placed against a shaping membrane (2) so that the sheet (1) and the membrane (2) are superimposed, and a deformation step following the positioning step, during which said shaping membrane (2) is deformed in order to induce a conjugated deformation of the flexible sheet (1) thus contributing to the shaping of the latter, said method being characterised in that the shaping of the flexible sheet (1) is carried out so that the flexible sheet (1) can be freely deformed by the deformation of the shaping membrane (2). The invention can be used for shaping plastic or elastomer materials.

Description

FORMING METHOD AND CORRESPONDING DEVICE

TECHNICAL AREA

The present invention relates to the general technical field of the shaping of flexible materials, and in particular plastics and elastomers, in particular to achieve flexible bags, preferably inflatable and used in different sectors, such as the sector health (medical and surgical implants), the lighting sector (outdoor lighting) or the sector of inflatable advertising objects, whether illuminated or not.

The present invention more particularly relates to a method of forming a flexible sheet of elastomer or plastic material comprising at least:

a positioning step, during which said sheet is attached against a forming membrane so that said sheet and membrane are superposed,

- And a deformation step which is subsequent to the positioning step and during which said forming membrane is deformed to cause a combined deformation of the flexible sheet contributing to the forming thereof.

The present invention also relates to a device for forming a flexible sheet of elastomer or plastic material comprising at least:

a forming membrane against which said sheet is intended to be attached so that said sheet and membrane are superimposed, a holding means making it possible to keep said sheets and membranes superimposed,

- A deformation means, for deforming said forming membrane to cause a combined deformation of the flexible sheet contributing to the forming of the latter.

PRIOR ART

Many technical sectors require the implementation of flexible bags, and in particular flexible bags that must remain sealed over relatively long periods of time, while being subject to severe environmental constraints.

Thus, in the health sector, it is known, for treating patients with obesity, to directly implant in their stomachs an intragastric balloon of sufficient volume to reduce the space available to patients. foods, and the speed of passage of these. These intragastric balloons are for example implanted orally endoscopically (without surgery).

Such balloons usually comprise at least one flexible bag, made of a biocompatible elastomeric material.

Said pocket is intended to be inflated, for example by air or physiological fluid, to impart to the balloon its therapeutic functional volume, which can reach 600 cm ³ .

In particular, a multi-pocket intragastric balloon is known, comprising on the one hand an external flexible silicone bag which forms the surface envelope of the balloon, and on the other hand an internal polyurethane bag, disposed inside the outer pocket and intended to be filled with air. The inner pouch thus acts like an air chamber vis-à-vis the outer pouch, that is to say that the inflation of the inner pouch inside the outer pouch causes the indirect inflation of the outer pocket.

Although this intragastric balloon of the prior art is generally satisfactory, its manufacturing process does not lack some shortcomings and disadvantages.

Thus, the manufacturing method used to produce the inner polyurethane bag of this balloon of the prior art has a quasi-artisanal character, which poses problems of repeatability and cost. In particular, the method of the prior art does not allow to control industrially precisely and repeatably the porosity of the wall of the pocket. The inner bag thus obtained is therefore likely to have a non-uniform porosity, with in particular areas of weakness having a porosity that may be too large. This porosity is indeed likely to cause progressive deflation of the inner bag. Such deflation would of course affect the therapeutic effectiveness of the balloon, since the ball must, to produce all its effects, remain inflated substantially to its nominal volume for a period of several months (eg about six months).

In addition, the manufacturing method of the prior art also does not allow precise control of the symmetry of the pocket.

This means that, despite all the vigilance exhibited by operators, it is common that the pocket obtained may not be truly spherical, but on the contrary present a defect of symmetry (due for example to a lower hemisphere having a volume greater than that of the upper hemisphere). An asymmetric internal pocket of course leads to a balloon that is, once inflated, also asymmetrical, and therefore whose use and efficiency are not optimal.

This is why the internal pores too porous and / or unsymmetrical must be eliminated, which increases the rate of rebus and hence the cost of manufacture.

To obtain a pocket of substantially spherical and symmetrical shape, it is known to sometimes use a manufacturing method implementing a deformation membrane and a mold of hemispherical shape for forming the inner pouch . Deformation of the forming membrane causes deformation of the inner bag against the walls of the mold, so that said pocket conforms to the shape of said walls.

Such a method, while it makes it possible to obtain an inner pouch of substantially spherical and symmetrical shape, is however particularly expensive and difficult to implement. It also requires expensive maintenance of the mold.

Similar problems exist in other technical fields, such as the field of luminaires, and in particular outdoor luminaires. Thus external luminaires are known comprising a flexible bag of PVC inflated with air and within which is disposed a light source, such as an ampoule. The bag thus equipped with its bulb can be mounted on a mast to serve as a means of lighting inside, or preferably outside, a building. Of course, this PVC bag must also have a tight character over a period of time that can be relatively long, especially when the luminaire is intended to be permanently installed. The inflated pocket surrounding the bulb must also, for aesthetic reasons, have a perfectly regular and symmetrical shape.

SUMMARY OF THE INVENTION

The objects assigned to the invention therefore aim to remedy the various disadvantages listed above and to propose a new forming method and a corresponding device for obtaining parts whose shape and porosity are finely and accurately controlled.

Another object of the invention is to provide a new forming method and a corresponding device for obtaining in a simple and reliable manner perfectly symmetrical pockets.

Another object of the invention is to provide a new forming method and a corresponding device particularly simple and economical.

Another object of the invention is to propose a new forming method and a corresponding device which make it possible to control in a particularly fine and precise manner the degree of porosity of the piece obtained.

Another object of the invention is to propose a novel forming method and a corresponding device which make it possible to obtain, in a simple and reliable manner, parts of precise and stable shape, even when said parts are obtained by the implementation of deformations. large amplitude. The objects assigned to the invention are achieved by means of a process for forming a flexible sheet of elastomer or plastic material comprising at least:

and a deformation step which is posterior to the positioning step and during which said forming membrane is deformed to cause a conjugate deformation of the flexible sheet contributing to the forming thereof, said forming process being characterized in that that the shaping of the flexible sheet is carried out so that the flexible sheet can deform freely under the effect of the deformation of the forming membrane.

The objects assigned to the invention are also achieved by means of a device for forming a flexible sheet of elastomer or plastic material comprising at least:

a forming membrane against which said sheet is intended to be attached so that said sheet and membrane are superimposed,

a holding means making it possible to keep said sheets and membranes superimposed,

deformation means, making it possible to deform said forming membrane to cause a combined deformation of the flexible sheet contributing to the forming of the latter, said forming device being characterized in that it is designed so that the flexible sheet can deform freely under the effect of the deformation of the forming membrane.

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 side view in section, a forming device according to the invention.

- Figure 2 illustrates, in a schematic sectional view, a detail of the device of Ia Figure 1 when the deformation means deforms the forming membrane.

BEST MODE OF REALIZING THE INVENTION

According to a first aspect, the invention relates to a forming method, that is to say a shaping method. The method of the invention is a method of forming a flexible sheet 1 of elastomer or plastic, that is to say a thin plate, film or membrane type, preferably initially flat. For example, the thickness of the flexible sheet 1 is between 10 microns and 8 mm, and even more preferably between 100 microns and 3 mm. The flexible sheet 1 preferably has a high deformation capacity, and in particular is easily extensible and stretchable in a large amplitude, preferably in all directions. For this purpose, the flexible sheet 1 is preferably made of a plastically deformable material, and preferably capable of undergoing large plastic deformations. For example, the flexible sheet 1 can be made of one or more of the following materials: polyurethane, PVC, EVA (ethylene-vinyl acetate), gas-barrier polymers such as ethylene vinyl alcohol (EVOH) ₁ polychloride vinylidene (PVDC), poly-acrylonitrile (PAN), polyamide (PA), bi-oriented polyamide, polyethylene terephthalate (PET) or bi-oriented polyethylene terephthalate. The flexible sheet 1 can also be made from a metallized polymer (for example by metal vapor deposition of the CVD type).

According to a non-illustrated embodiment, the sheet 1 has a monolayer nature, that is to say it is formed of a single film integrally. However, according to a preferred embodiment, the flexible sheet 1 advantageously has a multi-layer nature, that is to say that it consists of a stack of at least two superposed films. Thus, in the example illustrated in the figures, the flexible sheet 1 is constituted by a stack of two superposed films 1A, 1B. Preferably, the two films IA, 1B are identical and made in particular in the same material. In this case, the flexible sheet 1 thus forms a multilayer complex made by direct association of two flat flexible films 1A, 1B.

Preferably, the films 1A, 1B constituting the sheet 1 are mutually attached along a line of attachment 1C located at the interface between said films 1A, 1B. For example, the films 1A ₁ 1B may be bonded together by welding, so that the line of attachment 1C corresponds in this case to the weld bead binding the films 1A ₁ 1B them. It is of course conceivable that the films 1A ₁ 1 B are attached together by means other than welding, and are for example bonded by gluing or any other means. It is also conceivable that the films 1A, 1B are attached to each other over substantially their entire surface and not only according to a line of attachment.

Of course, the films 1A, 1B may also each consist of a multilayer complex resulting from the assembly, preferably over their entire contact surface, of elementary layers. For example, each film 1A, 1B may comprise a gas barrier polymer layer and a polypropylene (PP) or polyethylene (PE) layer. According to another example, each film 1A, 1B comprises a first layer (with a gas-barrier effect) of ethylene vinyl alcohol (EVOH), interposed between a second and a third layer of polyethylene (PE) or of polypropylene (PP), the polyethylene may be for example high density polyethylene or metallocene polyethylene. Each film 1A, 1B may also comprise an outer layer of polyamide (PA) covering said second and / or said third layer (s).

In order to achieve one of the preferred objects of the invention, namely the realization of a pocket from the sheet 1, it is preferable that the films 1A ₁ 1 B are mutually attached according to a line of attachment 1C substantially in the form of a loop, and preferably in the form of a closed loop, so as to form a pocket between said films 1A, 1B. In other words, the films 1A, 1B are connected to each other so as to form between them an interstitial space for forming a pocket. Preferably, the line of attachment 1C has substantially a circular shape, or at least globally circular. The invention is of course not limited to such a circular shape, and it is quite conceivable that the line of attachment 1C has a non-circular shape (corresponding for example to the profile of a bottle of soda), even even unsymmetrical. The line of attachment 1C may be substantially continuous (with nevertheless preferably openings allowing inflation / deflation of the pocket) or discrete (made by dotted lines).

As will be detailed in the following, the implementation of an attachment line 1C having substantially a circular shape makes it possible, after the implementation of the forming process according to the invention, to obtain a pocket having a substantially spherical character whose equatorial contour is preferably constituted by the line of attachment 1C itself.

The forming method according to the invention comprises at least one positioning step, during which the flexible sheet 1 is attached against a forming membrane 2 so that said sheet 1 and membrane 2 are superposed, as is illustrated in FIG. In other words, during the positioning step, the sheet 1 is plated, preferably directly and intimately, against and on the forming membrane 2, so as to form a stack with the latter.

It is entirely conceivable, without departing from the scope of the invention, for two flexible sheets to be attached to the membrane 2 respectively on each face of the latter, so that the membrane 2 is interposed between the said flexible sheets, the latter possibly being bonded together by a weld seam.

The forming membrane 2 also has a flexible character, with deformability properties comparable to those of the sheet 1. The forming membrane 2 is also in the form of a thin plate and is also preferably made of elastomer or plastic. In particular, the forming membrane 2 has an ability to be deformed, under the effect of an ad hoc solicitation, in a large amplitude, while being able to find, by elastic return when the bias disappears, its initial form of rest, which is preferably flat. For this purpose, the forming membrane 2 is preferably made of an elastomeric material, such as a rubber.

The positioning step thus makes it possible to superimpose two flexible membranes, namely a membrane intended to be shaped and constituted by the sheet 1, and a membrane intended to ensure the shaping and constituted by the forming membrane 2.

The forming method according to the invention also comprises a deformation step which is subsequent to the positioning step.

During this deformation step, the forming membrane 2 is deformed to cause a conjugate deformation of the flexible sheet 1. Thus, the forming membrane 2 causes, by deforming, a deformation of the flexible sheet 1 which is pressed against she. In other words, the flexible sheet 1 permanently marries the forming membrane 2 against and on which it is attached, so that the flexible sheet 1 adopts the deformed profile that the forming membrane 2 presents at the end of the deformation step, as shown in Figure 2.

The combined deformation of the flexible sheet 1 thus obtained contributes to the forming of said flexible sheet 1, that is to say that this deformation is performed to modify substantially permanently the shape of the flexible sheet 1 (which was for example initially plane). In other words, the deformation step is advantageously conducted to impart a permanent deformation to the sheet 1. The invention is therefore based in particular on the idea of controlling the deformation of the flexible sheet 1 by the deformation of the forming membrane 2, so that the control of the deformation of the forming membrane 2 makes it possible to control indirectly and to Fine and precise way the deformation of the flexible sheet 1. The thickness of the deformed flexible sheet 1 is thus controlled and controlled locally precisely, which therefore also allows to control precisely and locally the porosity of the deformed flexible sheet 1 .

Preferably, the shaping of the flexible sheet 1 is carried out solely thanks to the deformation of the forming membrane 2, that is to say that the flexible sheet 1 can deform freely under the effect of the deformation of the forming membrane 2. Thus, the deformation of said flexible sheet 1 is free manner without the constraint of a mold.

The flexible sheet 1 is therefore subjected to a constraint of unilateral shaping, that is to say on one of its faces. Only the deformation of the forming membrane 2 is at the origin of the deformation of the flexible sheet 1. In other words, it is in particular absolutely unnecessary, thanks to the forming process according to the invention, to deform the flexible sheet 1 within a mold.

The absence of mold significantly simplifies the manufacturing process, facilitating in particular its implementation, which reduces both the costs and the manufacturing time of the flexible sheet 1 formed. In addition, the only intervention of the forming membrane 2 of elastomer also reduces the maintenance costs of the equipment, including eliminating the costs of maintenance and restoration of the mold. Indeed, the forming membrane 2 is easily replaceable and at a lower cost. The deformation of the flexible sheet 1 is advantageously stopped when the forming membrane 2 passes through a light beam (not shown), adjustable in height. In other words, when during its deformation the flexible sheet 1, attached to the deformation membrane 2, intersects a light beam, preferably a laser beam whose height has been previously adjusted according to the desired deformation said deformation is stopped. Preferably, the stop deformation is triggered automatically without the intervention of an operator. The intervention of this light beam advantageously contributes to the precise and controlled control of the deformation of the flexible sheet 1 and also facilitates the implementation of the manufacturing process. It is of course conceivable, without going beyond the scope of this invention, to use other systems for detecting the evolution of the deformation.

Preferably, the method according to the invention further comprises a heating step which begins before the deformation step and during which the flexible sheet 1 is heated to soften it until it reaches predetermined ductility, the deformation step being conducted while the sheet 1 has said predetermined ductility. In other words, the deformation step is conducted while the flexible sheet 1 is softened by heating, so that the combined deformation of the flexible sheet 1 is hot deformation. In this case, the process according to the invention constitutes a thermoforming process.

Of course, it is not necessarily necessary, in some cases, to implement such hot deformation and it is quite possible to perform the deformation of the flexible sheet 1 without additional heating, that is to say say at room temperature. In this case, the deformation of the forming membrane 2 must be sufficient to deformation of the flexible sheet 1 in the plastic field, so that said deformation has a permanent character.

The implementation of a softening step of the flexible sheet 1 is however preferred because it facilitates the deformation operation, and in particular to perform this deformation operation in a relatively short time, which reduces the manufacturing time and therefore the corresponding costs.

Preferably, the forming membrane 2 has a resistance to deformation substantially greater than that of the flexible sheet 1. In other words, the forming membrane 2 is advantageously more difficult to deform (that is to say less flexible, or in other words more rigid) than the flexible sheet 1, which makes it possible to drive in a particularly efficient and precise way the deformation of the latter by deformation of the forming membrane 2.

According to the embodiment illustrated in the figures, during the deformation step, the forming membrane 2 is deformed so that it affects a hemispheroidal shape (see FIG. In this way, the flexible sheet 1 to be deformed, which follows the forming membrane 2, also has a hemispheroidal shape at the end of the deformation step. In the case where the flexible sheet 1 consists of a stack of several superimposed films, and for example of two superimposed films 1A, 1B as illustrated in the figures, each film 1A, 1B also adopts a substantially hemispherical shape, the lower film 1B being fitted into the upper film 1A whereas the line of attachment 1C preferably constitutes the circular base of the double hemisphere thus obtained. At the end of the deformation step, it is then sufficient to inflate the bag made between the films 1A, 1B to obtain a spheroidal balloon, the line of attachment 1C corresponding to the equatorial line of said balloon.

Thus, the forming method according to the invention makes it possible in this case to obtain a substantially spherical pocket in a particularly simple, reliable, precise and economical manner. Indeed, thanks to the fact that all 1A movies,

1 B constituting the flexible sheet 1 are subjected to a single deformation operation generated by the membrane 2, it is ensured that the hemispheres constituting the pocket (and respectively corresponding to the films 1A, 1B) will have substantially identical shapes, so that the pocket thus obtained will have a symmetrical and spherical character.

According to the embodiment illustrated in the figures, the process preferably comprises a preparation step (illustrated in FIG. 1), prior to the deformation step, during which the forming membrane 2 is attached to an opening of which is provided with a chamber 3 for sealing substantially said chamber 3 and thus obtain a closed chamber. For example, as shown in Figure 1, the membrane 2 has an opposite inner face and an opposite outer face, said forming membrane 2 resting by the periphery of its inner face against the rim surrounding the chamber 3 so as to close the latter. The flexible sheet 1 is attached against the outer face of the forming membrane 2, the lower film 1B being pressed against the outer face of the forming membrane 2.

As shown in FIG. 1, the flexible sheet 1 and the forming membrane 2 are preferably held pressed against the chamber 3 by means of a flange 4, preferably annular and positioned substantially concentrically at the opening of the chamber 3, so that the sheet 1 and the membrane 2 (that is to say the stack formed by the sheet 1 and the membrane 2) are sandwiched between firstly the chamber 3 (or more precisely the frame in which the chamber 3 is formed) and secondly the flange 4, under the effect of a peripheral clamping force, preferably annular, shown schematically by the arrows 5 in Figure 1.

Preferably, the flange 4 has a substantially circular and continuous shape. However, it is quite possible, without departing from the scope of the invention, that the flange 4 has a non-annular shape, or has a polygonal annular shape, and / or has a non-continuous character so that that it does not plate the stack sheet 1 / membrane 2 on all its perimeter but only in localized zones.

Preferably, in the configuration illustrated in the figures, the forming membrane 2 is deformed, during the deformation step, by providing an inflation fluid, and preferably a gaseous inflation fluid, such as air, in bedroom 3 closed. Thus, in the example illustrated in the figures, the forming membrane 2 is deformed by increasing the amount of air present in the chamber 3. This increase in the quantity of air generates a thrust on the forming membrane 2, which in response to this thrust, bombs to affect a hemispherical dome shape, as shown in Figure 2. Of course and as explained in the foregoing, the flexible sheet 1 permanently marries the forming membrane 2, so that the increase of the amount of air in the chamber 3 causes, through the membrane 2, the modification of the shape of the flexible sheet 1 which is stretched, and preferably stretched plastically, to affect it also a spherical shape conforming to the spherical shape of the forming membrane 2.

In order to finely control the forming of the sheet 1 with the aid of the membrane 2, it is preferable to firmly press the flexible sheet 1 directly against the forming membrane 2, by expelling any air present at the interface between the flexible sheet 1 and the forming membrane 2.

In the example illustrated in the figures, the increase of the quantity of air within the chamber 3 can be carried out, for example, by blowing air into said chamber 3 via an inlet. air 6 connected to a source of air, such as a compressor for example (not shown). Preferably, the increase in the amount of air is carried out progressively and continuously until reaching a predetermined level corresponding to the desired deformation of the forming membrane 2 and thus of the flexible sheet 1. As soon as the desired level of deformation, the supply of air is interrupted and the shape of the membrane 2 and the sheet 1 is thus frozen.

In the foregoing, the implementation of a deformation of the forming membrane 2 has been described by increasing the quantity of air in the chamber 3. Other embodiments are of course conceivable, for example at using a depression of the chamber 3 (removal of the air present in the chamber 3), or with the aid of a liquid inflation fluid instead of a gas such as air .

Preferably, the forming membrane 2 has a spatially variable resistance to deformation. In other words, the forming membrane 2 advantageously has a gradient of resistance to deformation, that is to say that its resistance to deformation is not constant and varies in space.

Preferably, the forming membrane 2 has an extra thickness in its center 2A, so that it has an increased resistance to deformation at its center 2A. For example, as this is more particularly visible in Figure 1, the forming membrane 2 advantageously has a central bead which contributes to locally increase the stiffness of the forming membrane 2 at its center 2A. This avoids excessive stretching of the membrane 2 at its center 2A when the amount of air increases in the chamber 3. This limitation of the stretching at the center 2A of the membrane 2 allows in return for limit the stretching of the flexible sheet 1 at its own center, which avoids at this point the formation of an area too thin and therefore porous. Thus, controlling the thickness of the forming membrane 2 makes it possible to precisely and differentially control the stretching of the flexible sheet 1 and therefore the porosity of the latter. In other words, the implementation of a forming membrane 2 of variable thickness makes it possible to obtain a flexible sheet 1 which, once shaped, has a substantially homogeneous and calibrated thickness.

Of course, the use of a forming membrane 2 of variable thickness is optional and it is quite possible to implement a forming membrane 2 of substantially constant thickness or deformation resistance, or of constant thickness. but of resistance to variable deformation due to the presence of a reinforcement integrated into the membrane.

The method described in the foregoing is particularly advantageous for the manufacture of a medical or surgical implant intended to be implanted in the body of a patient and comprising a pocket intended to be inflated to impart to the implant its functional volume. . Indeed, the process according to the invention makes it possible to obtain, as has been detailed in the foregoing, a pocket whose shape and thickness (and therefore the porosity) are finely and precisely controlled, so that once implanted, the pocket fulfills its functions perfectly during the entire treatment period, without the need to carry out re-inflationary operations in particular.

According to a particularly advantageous embodiment, the invention thus relates to a method of manufacturing an intragastric obesity treatment balloon intended to be implanted in the stomach of a patient to reduce the volume of the stomach. , said balloon comprising a bag to be inflated to impart to the balloon its functional volume, said method comprising the implementation of a forming method according to the foregoing description to obtain said bag. This forming method can thus be used to produce, from flat flexible sheets of elastomer or plastic material:

the external pocket of the intragastric balloon, forming the superficial envelope of the latter,

and / or the inner bag (or pouches) of said intragastric balloon, intended to be contained in the outer bag to be inflated with a fluid such as air or physiological fluid.

For example, the forming method described above is advantageously used to form a flexible sheet constituted by the stack of four superimposed polyurethane films attached together along a substantially circular line of attachment, said method thus permitting to obtain in a single forming operation a double wall spherical pocket. This double-walled spherical pocket is itself intended to be arranged in a flexible silicone envelope, so that the inflation of the double-walled spherical pocket allows indirect inflation of the silicone outer casing. The double-walled spherical pocket has a perfectly spherical and symmetrical outer shape, so that its inflation can be imparted to the pocket silicone exterior a perfectly spherical and symmetrical character, in the same way that an inner tube shapes the tire that receives it.

By controlling the porosity, it is possible to inflate the double wall bag with a gas, such as air, without fear of deflation of said pocket during the treatment period (which may for example last six months) .

The invention is of course not limited to the implementation of the forming process for producing medical implants.

According to another aspect, the invention thus relates to a method of manufacturing a luminaire comprising a pocket intended to receive a light source therein, said method comprising the implementation of a forming method according to the description which precedes to obtain said pocket.

Thanks to the forming process, it is for example possible to obtain a globe, preferably made of PVC, polyurethane or EVA, of perfectly spherical shape, non-porous. It is then possible to inflate this sphere, preferably with air, and to have inside the latter a light source to obtain a luminaire and in particular an outdoor luminaire.

According to yet another aspect, the invention relates to a method of manufacturing an inflatable advertising object comprising a pocket intended to be inflated by an inflation fluid (for example air or another gas), said method comprising placing implementing a forming method according to the foregoing description to obtain said pocket. It is thus possible, thanks to the invention, to obtain advertising balloons of various shapes. It is also possible, thanks to the forming precision that allows the invention and its repeatability, to print a pattern directly. precursor decorative or informative character on the flexible sheet 1 prior to its deformation, so that after deformation of the sheet 1, the precursor pattern, which was also deformed with the sheet 1, becomes a final pattern exactly in accordance with this that one wishes to see on the inflated object. Thus, the precision and repeatability of forming allowed by the invention make it possible to reliably obtain a given final pattern from a given precursor pattern. In other words, the precursor pattern integrates the deformation function obtained by the method of the invention, so as to restore, after deformation of the sheet 1, a final pattern (text, image) which appears undistorted on the surface pocket, once the latter inflated.

The invention also relates, in another aspect, a forming device 7 of a flexible sheet of elastomer or plastic. This forming device, illustrated in Figures 1 and 2, allows the implementation of the forming method described in the foregoing.

This forming device 7 comprises at least one forming membrane 2 against which the flexible sheet 1 to be shaped is intended to be reported so that said flexible sheet 1 and membrane 2 are superimposed (see Figure 1).

As indicated in the foregoing, the forming membrane 2 advantageously has a spatially variable resistance to deformation. For example, the forming membrane 2 has an extra thickness in its center 2A, so that it has an increased resistance to deformation at its center 2A, as already mentioned in the foregoing.

Preferably, the forming membrane 2 is made of an elastomeric material, such as a rubber. Such a material has in fact a great capacity of deformation while having the faculty, when the strain solicitation disappears, to return by itself precisely in its initial configuration.

The device 1 according to the invention also comprises at least one holding means 8 making it possible to keep said sheets 1 and membrane 2 superimposed. Preferably, the holding means 8 is designed to substantially prevent any relative sliding of the sheet 1 and the membrane 2 during the forming operation itself, as well as any relative sliding of the films 1A, 1B when the sheet 1 is multilayer.

The forming device 7 also comprises at least one deformation means, for deforming said forming membrane 2 to cause a combined deformation of the flexible sheet 1 contributing to the forming of the latter, as is explained in detail in the foregoing. This forming device 7 is designed so that the flexible sheet 1 can deform freely under the effect of the deformation of the forming membrane 2.

In other words, the forming device 7 of the present invention allows a free deformation, without the stress of a mold, of the flexible sheet 1, thanks to the deformation of the forming membrane 2. Such a forming device 7 advantageously reduces the material required for forming said flexible sheet 7 and thus contributes to facilitate and simplify the implementation of the corresponding manufacturing process and reduce costs and the manufacturing time.

Preferably, the deformation means is adapted to impart to the forming membrane 2 a hemispheroidal shape, as illustrated in FIG. 2. For example, the deformation means comprises a chamber 3 provided with an opening against which the forming membrane 2 is attached to substantially seal said chamber 3 and thus obtain a closed chamber 3.

The deformation means also preferably comprises means 6 for supplying an inflation fluid, and preferably a gaseous inflating fluid such as air, into the closed chamber 3. In this way, it is possible to deform the forming membrane 2 under the effect of increasing the amount of air in the chamber 3, so that the latter adopts a hemispherical curved shape, as shown in Figure 2 .

Advantageously, the holding means 8 comprises a flange 4, preferably annular, for holding the sheet 1 and the forming membrane 2 pressed against the chamber 3 (or more precisely against the frame in which the chamber 3 is formed), said flange 4 being intended to be positioned substantially concentrically at the opening of the chamber 3, so that the sheet 1 and the membrane 2 are sandwiched between the chamber 3 and the flange 4, as illustrated in FIG.

Advantageously, the device 7 comprises a means 9 for heating at least the flexible sheet 1 of elastomer or plastic. As shown in FIG. 1, the heating means 9 for heating the flexible sheet 1 may for example be positioned above the flexible sheet 1, opposite the forming membrane 2. The heating means 9 thus makes it possible to soften the flexible sheet 1 so as to ensure the forming of the latter by hot deformation of the forming membrane 2, as explained in detail in the foregoing.

The invention also relates as such to an installation for manufacturing an intragastric obesity treatment balloon intended to be implanted in the stomach of a patient to reduce the volume of the stomach, said balloon comprising a bag intended to be inflated to impart to the balloon its functional volume, said installation comprising an apparatus for manufacturing said bag from a flexible sheet 1 of elastomer or plastic, said apparatus itself comprising a forming device according to to the above description.

The invention also relates as such to an installation for manufacturing a luminaire comprising a pocket intended to receive a light source therein, said installation comprising an apparatus for manufacturing said pocket from a flexible sheet 1 made of elastomer or plastic, said apparatus itself comprising a forming device according to the foregoing description.

Finally, the invention finally relates to an installation for manufacturing an advertising object comprising a pocket intended to be inflated by an inflation fluid, said installation comprising an apparatus for manufacturing said pocket from a flexible sheet of elastomer or plastic, said apparatus itself comprising a forming device according to the foregoing description. POSSIBILITY OF INDUSTRIAL APPLICATION

The invention finds its industrial application in processes and devices for forming flexible bags of elastomer.

Claims

1 - Process for forming a flexible sheet (1) of elastomer or plastic material comprising at least:

a positioning step, during which said sheet (1) is attached against a forming membrane (2) so that said sheet (1) and membrane (2) are superposed,

- and a deformation step which is subsequent to the positioning step and during which said forming membrane (2) is deformed to cause a conjugate deformation of the flexible sheet (1) contributing to the forming thereof, said method being characterized in that the shaping of the flexible sheet (1) is carried out so that the flexible sheet (1) can deform freely under the effect of the deformation of the forming membrane (2).

2 - Process according to claim 1 characterized in that the sheet (1) is constituted by a stack of at least two films (1A, 1B) superimposed.

3 - Process according to claim 2 characterized in that said films (1A, 1B) are mutually attached according to a fastening line (1C) substantially in the form of a loop, so as to form a pocket between said films (1 A, 1 B).

4 - Process according to claim 3 characterized in that the line of attachment (1C) has substantially a circular shape. - Method according to one of claims 1 to 4 characterized in that during the deformation step, the forming membrane (2) is deformed so that it affects a hemispheroidal shape.

- Method according to one of claims 1 to 5 characterized in that it comprises a preparation step, prior to the deformation step, during which the forming membrane (2) is attached to an opening which is provided a chamber for substantially sealing said chamber (3) and thus obtaining a closed chamber (3), and in that during the deformation step the forming membrane (2) is deformed by adding a inflation fluid in the chamber (3) close.

- Method according to claim 6 characterized in that the sheet (1) and the membrane (2) of forming are held pressed against the chamber (3) with a flange (4) positioned substantially concentrically to said opening, so that the sheet (1) and the membrane (2) are sandwiched between the chamber (3) and the flange (4).

- Method according to one of claims 1 to 7 characterized in that the forming membrane (2) is made of an elastomeric material, such as a rubber, said forming membrane (2) having a substantially higher resistance to deformation to that of the flexible sheet (1).

- Method according to one of claims 1 to 8 characterized in that the forming membrane (2) has a resistance to deformation spatially variable.

- Method according to claim 9 characterized in that the forming membrane (2) has an extra thickness in its center (2A), so as to it has increased resistance to deformation at its center (2A). 1 - Method according to one of claims 1 to 10 characterized in that the deformation of the flexible sheet 1 is stopped when the forming membrane 2 passes through a light beam. 2 -Procédé according to one of claims 1 to 11 characterized in that the flexible sheet (1) is made of one or more of the following materials: polyurethane, PVC, EVA (ethylene-vinyl acetate), polymers with a barrier effect to gases such as ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), poly-acrylonitrile (PAN), polyamide (PA), bi-oriented polyamide, polyethylene terephthalate (PET) or polyethylene terephthalate biaxially oriented. 3 - Process according to one of claims 1 to 12 characterized in that it comprises a heating step which begins before the deformation step and during which is heated at least the flexible sheet (1) to soften it up to in that it reaches a predetermined ductility, the deformation step being conducted while the sheet (1) has said predetermined ductility.

14 - Method for producing an intragastric obesity treatment balloon intended to be implanted in the stomach of a patient to reduce the volume of the stomach, said balloon comprising a pocket intended to be inflated to impart the balloon its functional volume, characterized in that it comprises the implementation of a forming method according to one of claims 1 to 13 to obtain said pocket.

15 - A method of manufacturing a luminaire comprising a pocket adapted to receive a light source therein, characterized in that comprises the implementation of a forming method according to one of claims 1 to 13 to obtain said pocket.

- A method of manufacturing an inflatable advertising object comprising a pocket intended to be inflated by an inflation fluid, characterized in that it comprises the implementation of a forming method according to one of claims 1 to 13 for obtain said pocket.

- Device (7) for forming a flexible sheet (1) of elastomer or plastic material comprising at least:

- a forming membrane (2) against which said sheet (1) is intended to be reported so that said sheet (1) and membrane (2) are superimposed,

- a holding means (8) for maintaining superimposed said sheet (1) and membrane (2),

a deformation means for deforming said forming membrane (2) to cause a combined deformation of the flexible sheet (1) contributing to the forming thereof, said forming device being characterized in that it is designed so that the flexible sheet (1) can deform freely under the effect of the deformation of the forming membrane (2).

-Dispositif (7) according to claim 17 characterized in that the deformation means is designed to impart to the forming membrane (2) a hemispheroidal shape.

-Dispositif (7) according to one of claims 17 or 18 characterized in that the deformation means comprises firstly a chamber (3) provided with an opening against which the forming membrane (2) is reported to close substantially sealing said chamber (3) and thus obtain a closed chamber (3), and secondly a means (6) for supplying an inflation fluid into the closed chamber (3).

- Device (7) according to claim 19 characterized in that the holding means (8) comprises a flange (4) for holding the sheet (1) and the forming membrane (2) pressed against the chamber (3), said flange (4) being intended to be positioned substantially concentrically to said opening, so that the sheet (1) and the membrane (2) are sandwiched between the chamber (3) and the flange (4).

- Device (7) according to one of claims 17 to 20 characterized in that the forming membrane (2) has a resistance to deformation spatially variable.

- Device (7) according to claim 21 characterized in that the forming membrane (2) has an extra thickness in its center (2A), so that it has an increased resistance to deformation at its center (2A) .

- Device (7) according to one of claims 17 to 22 characterized in that the forming membrane (2) is made of an elastomeric material, such as a rubber.

- Device (7) according to one of claims 17 to 23 characterized in that it comprises means (9) for heating at least the flexible sheet (1) of elastomer or plastic.

- An intragastric obesity treatment balloon manufacturing facility for implantation in the stomach of a patient to reduce stomach volume, said balloon comprising a bag to be inflated to impart on the stomach. balloon its functional volume, said installation being characterized in that it comprises an apparatus for manufacturing said bag from a flexible sheet of elastomer or plastic material, said apparatus comprising itself a device (7) according to one of claims 17 to 24.

- Installation for manufacturing a luminaire comprising a pocket for accommodating a light source therein, said installation being characterized in that it comprises an apparatus for manufacturing said pocket from a flexible sheet of elastomer or material plastic, said apparatus itself comprising a device (7) according to one of claims 17 to 24.

- Installation for manufacturing an advertising object comprising a pocket intended to be inflated by an inflation fluid, said installation being characterized in that it comprises an apparatus for manufacturing said bag from a flexible sheet of elastomer or plastic material, said apparatus itself comprising a device (7) according to one of claims 17 to 24.