Pressure balancing membrane

Abstract

The invention relates to a pressure balancing membrane (11) comprising a membrane (1), characterized in that the membrane (1) is sandwiched by a reinforcement border (4).

Description

Pressure balancing membrane

[0001] The present invention relates to a pressure equalization membrane for attachment to the surface of an article (e.g., a housing containing electronic components) at a pressure equalization opening.

[0002] Many engineering devices (e.g., in the fields of vehicles, construction, and housing) have housings, usually equipped with seals, that contain electronic components, and therefore must be perfectly sealed so as not to damage the electronic components and thus extend the life of said devices. Examples include the housings of earthmoving equipment, road construction equipment, cranes, forklifts, tractors, or any other vehicle used in agriculture. It may also be a waterproof housing for a car headlight or a floodlight for external use (e.g., to illuminate a garden or a monument).

[0003] It is well known to provide one or more openings in these boxes, known as "pressure balancing openings".

[0004] Indeed, temperature variations during the day, seasons or during a change in altitude or even due to the production of heat by the device itself during its operation can cause pressure differences within a waterproof case. A sudden drop in temperature can create a vacuum inside the case. If this pressure difference is not dissipated, the vacuum exerts continuous tension on the seals of the case which ensure its watertightness. Over time, this can cause the seals to wear, allowing moisture and other contaminants (e.g. dust, dirt) to enter the case which will damage and / or oxidize the electronic components.

[0005] These pressure-balancing openings are therefore necessary to allow the air contained within the housing to expand, to be evacuated (in the event of an increase in temperature) or to flow in (in the event of cooling).

[0006] For example, the electronic components of an automobile, designed in particular to control the parameters of the automobile, produce during heat operation which generates self-heating of said electronic components but also heating of the air present within the housing. Without pressure balancing thanks to these pressure balancing openings, excess pressure could occur within the housing, reaching 300, 500 or 700 mbar depending on the ambient temperature and the intensity of use of the electronic components (in other words their electrical energy consumption).

[0007] Additionally, the presence of moisture within a waterproof enclosure can be very damaging to the device. When water vapor enters a waterproof enclosure and has no way to escape, it condenses and becomes liquid. If this condensation remains inside the waterproof enclosure, it risks compromising the proper functioning of the electronic components, particularly by oxidizing them.

[0008] Finally, the pressure equalization openings must not be exposed to dirt (dust, wind-borne particles), rain, external elements (e.g. insects, gravel, sand) so as not to damage the electronic components inside the waterproof housings.

[0009] Therefore, for all these reasons, it is known to cover these openings with pressure equalizing membranes.

[0010] These pressure balancing membranes are therefore designed to: - allow gas exchanges so as to balance the pressures within the housing (depending on the different climatic events or the operation of the elements of the housing or more generally of the device in which the housing is integrated) and to reduce condensation within the housing which can oxidize sensitive electronic components, - prevent dirt (e.g. particles carried by the wind or dust), water, humidity, mold, external elements (insects, gravel, sand) from entering the housing so as not to damage the electronic components so that they operate reliably and durably, regardless of the conditions of use of the device comprising said housing.

[0011] Additionally, if the case contains a battery, its charging cycles may generate heat and emit hydrogen or other gases. This may be the cause explosions. Pressure-equalizing membranes effectively dissipate these gases. Thus, by continuously balancing pressures within the housing, such membranes reduce the risk of explosion.

[0012] In other words, these pressure-balancing membranes are designed to protect electronic components in the harshest environments and conditions. They combine permeability to gases (especially air) with protection of electronic components against the various external elements and contaminants mentioned above (dirt, dust, water, humidity, insects, sand, gravel, etc.).

[0013] More specifically, with regard to gas permeability, these membranes provide a compact ventilation structure, easily installed and integrated on the device (for example on a housing containing electronic components).

[0014] Pressure balancing diaphragms are designed to quickly balance pressure variations within sealed enclosures effectively preventing the aforementioned internal voids or pressure build-ups that: - put the seals of waterproof housings under pressure and damage them prematurely, - attract the aforementioned external contaminants inside the waterproof housings.

[0015] These pressure balancing membranes must therefore be mechanically robust enough to be able to withstand bad weather, the aforementioned external contaminants (particularly gravel), as well as the pressure fluctuations mentioned above.

[0016] Reliable and durable pressure-balancing diaphragms extend the life of the device, reducing its maintenance costs.

[0017] To ensure all these functions listed above, the pressure balancing membranes are generally made of a microporous film of polymer material, preferably polytetrafluoroethylene, hereinafter abbreviated as "PTFE". This film of polymer material is sufficiently microporous to allow gas exchange (particularly air) through the membrane while presenting a certain sealing and robustness to prevent liquids or other aforementioned contaminants (dirt, sand, gravel, insects) from passing through said membrane. The thickness of such membranes made of PTFE is of the order of 300 μm.

[0018] However, PTFE has the disadvantages of being an expensive material, non-recyclable, requiring toxic and hazardous materials for its production and producing greenhouse gases or toxic products when heated. Therefore, in order to limit the costs and environmental impact of the pressure equalization membrane without reducing its robustness and its gas permeability and liquid sealing functions, it is known to limit the amount of PTFE by providing a two-layer membrane which has: - a l ère PTFE film layer of reduced thickness compared to monolayer PTFE membranes, namely from 20 pm to 30 pm, - a 2 ème layer of textile material (about 100 μm thick) which has, for example, been fixed to the l ère PTFE film layer with a plurality of glue dots with a thickness of about 10 μm.

[0019] In this embodiment, it is known to those skilled in the art that the pressure balancing membrane must be fixed to the pressure balancing opening opening into a sealed space of a device such that: - the 2 ème layer of textile material either opposite the waterproof space and - the l ère layer of PTFE film facing the outside of this sealed space.

[0020] In this way, the textile material is not at risk of being delaminated or torn off the PTFE film layer when the pressure equalization membrane is subjected to drastic external conditions (e.g. climatic: heavy rain) or comes into contact with external elements (e.g. gravel).

[0021] However, this embodiment is not entirely satisfactory, because the l èreSince the PTFE film layer is thinner, it can be more easily damaged than a single-layer PTFE film membrane. For example, in the case of a car headlight housing, the membrane can be more easily abraded, scratched or impacted. This will reduce its watertightness, and consequently that of the housing, and have an impact on the lifespan of the device.

[0022] Finally, pressure balancing membranes are generally provided over the entire perimeter of the face intended to be opposite the confined space of the device with a layer of a means of fixing to the device. This means of fixing is generally in the form of a frame whose external edge corresponds to the perimeter of the membrane and which has a face covered with an adhesive to be able to fix the membrane at the pressure balancing opening. Thus, a significant part of the surface of the membrane (i.e. all around) is covered by the fixing means and therefore does not contribute to the aforementioned gas exchanges. In other words, a significant part of the pressure balancing membrane is “sacrificed” to allow its fixing on the device.

[0023] US patent application 2014 / 0283691 A1 describes a sealed ventilation structure that includes a housing having an opening and a breathable, sealed membrane that covers the opening. A space inside and a space outside the housing communicate with each other through the opening covered by the membrane. The membrane comprises two layers of material. Double-sided adhesives serve as a means of attaching the membrane to the housing and to the electronic component to be protected, which the housing contains. These double-sided adhesives are located flush with the membrane. None of these adhesives protrude beyond the perimeter of the membrane.

[0024] US Patent 9,875,733 B2 describes a ventilation device which comprises a membrane decomposing into a central portion and a peripheral portion surrounding said central portion. The peripheral portion is connected: - at the level of a l èrefacing the membrane to a layer of foam laminate having an adhesive face; and - at the level of a 2 ème face of the membrane to a double-adhesive polyester film.

[0025] The laminate layer and the double-adhesive polyester film sandwich the membrane flush around its entire perimeter.

[0026] In summary, the pressure balancing membranes known to date have various disadvantages (depending on their different embodiments detailed above) which include the expensive and non-ecological nature of PTFE, the lack of robustness in the face of bad weather or external elements (gravel) with the risk of tearing or loss of sealing.

[0027] The inventors of the present invention sought to overcome these drawbacks and developed a pressure equalizing membrane having the following advantages: - said membrane may contain a reduced quantity of PTFE to reduce its economic and environmental impact; - excellent durability; - excellent resistance to drastic climatic conditions and the operation of the device in which the said membrane is incorporated, as well as to the aforementioned external elements (gravel, dust, etc.).

[0028] The present invention thus relates to a pressure balancing membrane comprising a membrane and a reinforcing edge, part or all of the periphery of said membrane is sandwiched with said reinforcing edge which comprises a 1 er element and a 2 ème element, the 1 er element and the 2 ème element each comprises a support layer, the support layer of the 1 er element presents a l ère face and a 2 ème face, the support layer of the 2 ème element presents a lère face and a 2 ème face, said pressure balancing membrane is characterized in that: - part of the 2 ème face of the support layer of 2 ème element is fixed on a part of the l ère face of the support layer of 1 er element, the remaining part of the 2 ème face of the support layer of 2 ème element is fixed on a part of the membrane, as well as the remaining part of the l ère face of the support layer of 1 er element is fixed on a part of the membrane or - the entire 2 ème face of the support layer of 2 ème element is fixed on the membrane and part of the l ère face of the support layer of 1 er element is fixed on the membrane.

[0029] The l ère face of the support layer of 2 èmeelement of the reinforcing edge is intended to be fixed on a device provided with a confined space opening onto a pressure balancing opening so that the pressure balancing membrane according to the invention covers said opening of the device.

[0030] The 2 ème face of the support layer of 1 er element of the reinforcing edge is intended to be in contact with the environment external to the confined space leading to the pressure balancing opening which is covered by the pressure balancing membrane according to the invention.

[0031] In the embodiment of the invention in which the entire 2 ème face of the support layer of 2 ème element is fixed on the membrane and part of the l ère face of the support layer of 1 er element is fixed on the membrane, the remaining part of the l ère face of the support layer of 1er element of the reinforcing edge will be intended to be fixed on a device, more precisely on the perimeter of a pressure balancing opening with which said device is provided.

[0032] Preferably, the entire perimeter of the membrane is sandwiched with the reinforcing edge.

[0033] In one embodiment of the invention, a portion of the membrane perimeter is sandwiched with the reinforcing edge. Preferably, more than 20%, more preferably more than 50%, of the membrane perimeter is sandwiched with the reinforcing edge.

[0034] In the context of the present invention, the term "part or all of the perimeter of the membrane is sandwiched with the reinforcing edge which comprises a 1 er element and a 2 ème element" that said membrane is located between said 1 er element and the 2 èmeelement. According to embodiments of the invention, the 1 er element and the 2 ème element may both protrude from the perimeter of the membrane or according to other embodiments of the invention, the 1 er element only may protrude from the perimeter of the membrane and the 2 ème element will be located flush with the perimeter of the membrane. All these embodiments of the invention have in common that the membrane is always located between the 1 er element and the 2 ème element, therefore well sandwiched by the reinforcing edge.

[0035] Sandwiching the membrane with a reinforcing edge has the following advantages: not only does the reinforcing edge strengthen the membrane and therefore make it more resistant to drastic climatic conditions or external aggressions (e.g. gravel) which are likely to damage and / or tear it off, but it also allows the necessary quantity of membrane to be reduced. In fact, due to the sandwiching of the membrane with the reinforcing edge, it is no longer necessary for a significant portion of the membrane to be "sacrificed" to enable it to be fixed to the device. In fact, a portion of the reinforcing edge contributes to the fixing of the pressure balancing membrane according to the invention to the device.

[0036] The pressure balancing membrane according to the invention comprises a membrane, for example a membrane as known from the state of the art and examples of which have been detailed above.

[0037] The membrane can thus present the following technical characteristics which are not limiting.

[0038] The membrane can have any geometric shape. For example, the membrane can be square, rectangular, oval, round, triangular or any other polygonal shape.

[0039] The membrane area can be between 0.1 cm 2 and 100 cm 2 , preferably between 1 cm 2 and 30 cm 2 .

[0040] The membrane thickness can be between 20 pm and 2 mm.

[0041] The membrane may comprise at least one microporous material and which has breathability, measured by an air flow rate passing through the membrane under pressure of +70 mbar, between 10 and 10000 mL / min / cm 2 .

[0042] The membrane can be single-layer or multi-layer. If it is multi-layer, it is preferably two-layer.

[0043] In embodiments of the invention, the membrane comprises at least one microporous film of polymeric material. It may be a polymeric material chosen from polymers having a low surface energy, preferably less than 40 mN / cm. The polymeric material may be chosen from PTFE, polychlorotrifluoroethylene (hereinafter abbreviated as “PCTFE”), polyvinyl fluoride (hereinafter abbreviated as “PVF”), polysiloxane, polycarbonate (hereinafter abbreviated as “PC”) and polyester. The microporous film of polymeric material preferably has pores with a size of between about 0.01 μm and about 50 μm. Most preferably, the polymeric material of the membrane is PTFE.

[0044] In the context of the present invention, in order to allow the aforementioned gas exchanges through the membrane, the film of polymer material is microporous.

[0045] In embodiments of the invention, the membrane is single-layer and comprises a microporous film of polymeric material, preferably of a polymeric material as described above. In other words, the membrane is a single-layer microporous film of polymeric material which is selected from PTFE, PCTFE, PVF, polysiloxane, PC and polyester. In these embodiments of the invention, the thickness of said membrane may be between 20 μm and 2 mm.

[0046] Examples of such single-layer membranes include the membrane marketed by MICROVENT under the trade name MV72040, the membrane marketed by GORE under the trade name AVS 9 and the membrane marketed by BERGHOF under the trade name M40W.

[0047] In other embodiments of the invention, the membrane is bilayer and comprises a l èremicroporous film layer of polymeric material, for example of a polymeric material as described above and a 2 ème layer of textile material which is fixed on said l ère microporous film layer of polymer material.

[0048] The textile material may be selected from textiles based on polyethylene terephthalate (hereinafter abbreviated as "PET"), polyamides, polypropylene, polyethylene, acrylic, PTFE, elastane, glass fibers, carbon or cellulose. Preferably, these are textiles based on PET or polyamides. The textile material may be obtained by a weaving process or by agglomeration of fibers or yarns such as nonwovens and felts.

[0049] Thus, in one embodiment of the invention, the membrane is bilayer and comprises a l èremicroporous film layer of polymer material selected from PTFE, PCTFE, PVF, polysiloxane, PC and polyester and a 2 ème layer of textile material which is fixed on said l ère microporous film layer of polymer material, said textile material being chosen from textiles based on PET, polyamides, polypropylene, polyethylene, acrylic, PTFE, elastane, glass fibers, carbon or cellulose.

[0050] In this embodiment of the invention, the thickness of the l ère microporous film layer of polymer material can be between 10 pm and 500 pm and the thickness of the 2 ème layer of textile material can be between 10 pm and 1990 pm.

[0051] The 2 ème layer of textile material can be attached to the l èrelayer of microporous film of polymer material with an adhesive suitable for adhesion between the textile material and the polymer material (for example: a cyanoacrylate-based adhesive or a hot-melt or heat-reactivatable adhesive) or with another means of fixing consisting of heat-sealing the textile material with the polymer material. The fixing of the 2 ème layer of textile material is advantageously carried out on a part of the l ère layer of microporous film of polymer material so as to always allow the aforementioned gas exchanges through the membrane. In other words, the means of fixing the textile material and the film of polymer material is chosen appropriately so as not to hinder gas exchanges through the membrane. This choice is perfectly within the reach of a person skilled in the art.

[0052] These embodiments of the invention in which the membrane is bilayer have the advantages of reducing the cost and environmental impact of the pressure balancing membrane. Indeed, the membrane comprises a reduced quantity of microporous film of polymeric material (preferably PTFE) which is generally expensive and the synthesis process of which has an impact on the environment.

[0053] Examples of such two-layer membranes include the membrane marketed by PARKER under the trade name Q.BV657D, the membrane marketed by BERGHOF under the trade name M100WL and the membranes marketed by DONALDSON under the trade names EN0711066 and EN0701435.

[0054] In other conceivable embodiments of the invention, the membrane comprises more than 2 layers of materials. For example, it may be an alternation of layers of films of polymeric materials and textile materials.

[0055] The 1st er and the 2 ème elements of the reinforcing border may each have the shape of a frame whose opening has a shape similar to the perimeter of the membrane.

[0056] In one embodiment of the invention, the external dimensions of the frame of the 1 er element and 2 ème element of the reinforcing edge can be identical.

[0057] In another embodiment of the invention, the external dimensions of the frame of the 1 er element of the reinforcing edge may be greater than the external dimensions of the frame of the 2 ème element of the reinforcing edge. In this embodiment, a portion of the face of the 1er element which is opposite to that intended to be in contact with the external environment will be intended to be fixed on a device on the periphery of a pressure balancing opening with which it is provided.

[0058] The thickness of the 1 er The reinforcement edge element can be between 20 pm and 500 pm.

[0059] The thickness of the 2 ème The reinforcement edge element can be between 30 pm and 500 pm.

[0060] In one embodiment of the invention: - the 1 er element of the reinforcing edge can cover between 5% and 60% of the membrane surface, - the 2nd ème reinforcement edge element can cover between 5% and 70% of the membrane surface, - the 2nd ème reinforcement edge element can cover between 0% and 90% of the surface of the 1 er element of the reinforcing edge.

[0061] As explained above, the 2 ème element of the reinforcing edge can be flush with the perimeter of the membrane. In this case, there is no overlap of the 2 ème element with 1 er element of the reinforcement border, in other words 0% overlap of the 2 ème element with 1 er element.

[0062] The percentage of membrane coverage by the 1 er element of the reinforcing edge is suitably chosen to reinforce the pressure balancing membrane according to the invention so that it is not torn off and / or damaged when it is subject to drastic climatic conditions and / or in contact with external elements (for example gravel).

[0063] The percentage of membrane coverage by the 2 èmeelement of the reinforcing edge is suitably chosen to allow good fixing of the pressure balancing membrane according to the invention at the pressure balancing opening of the device. Furthermore, in the embodiment of the invention in which the external dimensions of the frame of the 1 er element of the reinforcing edge are greater than the external dimensions of the frame of the 2 ème element of the reinforcing edge, the 1 er element also contributes to the fixing of the pressure balancing membrane according to the invention at the pressure balancing opening of the device.

[0064] The recovery percentage of 1 er element of the reinforcement border by the 2 ème element of the reinforcing edge is chosen appropriately to ensure good reinforcement of the membrane which is sandwiched between the 1 er element and the 2 èmeelement of the reinforcing border. In fact, the assembly constituted by the part of the 1 er element of the reinforcement border and by the part of the 2 ème element of the reinforcing edge which are in contact with each other constitutes an excellent reinforcement of the pressure balancing membrane according to the invention.

[0065] Advantageously, the percentage of covering of the membrane by the 2 ème element of the reinforcement edge is greater than the percentage of covering of the membrane by the 1 er element of the reinforcing edge. This allows excellent fixing of the pressure balancing membrane according to the invention on the periphery of a pressure balancing opening of a device by means of the 2 ème element of the reinforcing edge.

[0066] On all or part of the perimeter of the membrane, between 0.5 mm and 20 mm, preferably between 1 mm and 10 mm, more preferably between 1 mm and 5 mm, of the membrane can be covered by the 1 er element of the reinforcing edge. This means that when the membrane is for example rectangular in shape, over all or part of the width of the membrane and over all or part of the length of the membrane, between 0.5 mm and 20 mm of the membrane is covered by the 1 er element of the reinforcing edge.

[0067] Between 0.5 mm and 20 mm, preferably between 1 mm and 10 mm, more preferably between 1 mm and 5 mm, of the 1 er The reinforcement edge element may protrude over all or part of the perimeter of the membrane. This means that when the membrane is, for example, rectangular in shape, between 0.5 mm and 20 mm of the 1 erelement of the reinforcing edge may protrude over all or part of the width of the membrane and over all or part of the length of the membrane.

[0068] On all or part of the perimeter of the membrane, between 0.5 mm and 20 mm, preferably between 1 mm and 10 mm, more preferably between 1 mm and 5 mm, of the membrane can be covered by the 2 ème element of the reinforcing edge.

[0069] Between 0.5 mm and 20 mm, preferably between 1 mm and 10 mm, more preferably between 1 mm and 5 mm, of the 2 ème element of the reinforcing edge may protrude over all or part of the perimeter of the membrane.

[0070] The material of the support layer of the 1 er element and 2 èmeThe reinforcing edge element may be selected from PET, poly(ethylene naphthalate) (abbreviated as "PEN"), polyvinyl chloride (abbreviated as "PVC"), polyamide, polypropylene and metal foil. The material of the backing layer of the 1 er element may be the same or different from the material of the support layer of the 2 ème element.

[0071] The thickness of the support layer of the 1 er element of the reinforcing edge may be between 15 pm and 200 pm, preferably between 30 pm and 100 pm.

[0072] The thickness of the support layer of the 2 ème element of the reinforcing edge may be between 15 pm and 200 pm, preferably between 30 pm and 100 pm.

[0073] The support layer of the 1 er element may have a Young's modulus (measured according to ISO 527) of between 0.5 GPa and 200 GPa, preferably between 1 GPa and 100 GPa, for example 5 GPa.

[0074] The support layer of the 2 ème element may have a Young's modulus (measured according to ISO 527) between 0.5 GPa and 200 GPa, preferably between 1 GPa and 100 GPa, for example 5 GPa.

[0075] The support layer of the 1 er element may have an elasticity, namely the force to obtain 5% elongation (measured according to ISO 527), greater than 10 MPa, preferably greater than 50 MPa, for example 110 MPa.

[0076] The support layer of the 2 ème element may have an elasticity, namely the force to obtain 5% elongation (measured according to ISO 527), greater than 10 MPa, preferably greater than 50 MPa, for example 110 MPa.

[0077] The physical properties of the support layers of the 1 er element and 2 ème element are chosen appropriately so that the reinforcing edge reinforces the membrane as explained above.

[0078] In embodiments of the invention, the l ère face of the support layer of 1 er element of the reinforcing edge and the 2 ème face of the support layer of 2 ème The reinforcement edge element can be covered with an adhesive.

[0079] Part of the 2 ème face of the support layer of 2 ème element of the reinforcing border can be glued on a part of the l ère face of the support layer of 1 er element of the reinforcing edge and, the remaining part of the 2 ème face of the support layer of 2 ème The reinforcing edge element can be glued to a part of the membrane, as well as the remaining part of the l ère face of the support layer of 1 er The reinforcing edge element can be glued to a part of the membrane.

[0080] Or the whole of 2 èmeface of the support layer of 2 ème element of the reinforcing edge can be glued on the membrane and part of the l ère face of the support layer of 1 er element of the reinforcing edge can be glued to the membrane. The remaining part of the l ère face of the support layer of 1 er element of the reinforcing edge will be intended to be fixed on a device on the perimeter of a pressure balancing opening with which it is provided.

[0081] The adhesive may advantageously be chosen from pressure-sensitive adhesives, for example acrylic, silicone, rubber or polyurethane-based adhesives.

[0082] The adhesive may optionally be tinted, for example with the incorporation of pigments or dyes so that the 1 er element and the 2 ème element of the reinforcing edge has the same color or a color similar to the color of the membrane.

[0083] The thickness of the adhesive may be between 5 pm and 500 pm, preferably between 25 pm and 100 pm.

[0084] The l ère face of the support layer of 2 ème element of the reinforcing edge may further be covered with an adhesive. This allows the pressure equalization membrane according to the invention to be fixed to a device in such a way that it covers a pressure equalization opening of the device. The l ère face of the support layer of 2 ème The reinforcing edge element is fixed to the device around the edge of the pressure equalization opening.

[0085] The adhesive may advantageously be chosen from pressure-sensitive adhesives, for example acrylic, silicone, rubber or polyurethane-based adhesives.

[0086] The thickness of the adhesive may be between 5 pm and 500 pm, preferably between 25 pm and 100 pm.

[0087] In other embodiments of the invention, the l ère face of the support layer of said 2 ème element is devoid of adhesive. In these embodiments, an adhesive may be present around the perimeter of a pressure-equalizing opening of a device so as to secure the ère face of the support layer of 2 ème element of the reinforcing edge, on this adhesive. The adhesive can advantageously be chosen from pressure-sensitive adhesives, for example acrylic, silicone, rubber or polyurethane-based adhesives.

[0088] In other embodiments of the invention, the entire l ère face of the support layer of 2 èmeelement of the reinforcing edge, can be fixed by thermal welding around the perimeter of said pressure balancing opening.

[0089] In one embodiment of the invention, a portion of the 2 ème face of the support layer of 2 ème element of the reinforcing edge is fixed by thermal welding on a part of the l ère face of the support layer of 1 er element of the reinforcing edge. In addition, the remaining part of the 2 ème face of the support layer of 2 ème element is fixed by thermal welding on a part of the membrane and the part remaining of the l ère face of the support layer of 1 er element is fixed by thermal welding on a part of the membrane.

[0090] In another embodiment of the invention, the entire 2 ème face of the support layer of 2 èmeThe reinforcement edge element is fixed by thermal welding to the membrane and part of the l ère face of the support layer of 1 er The reinforcing edge element is fixed by thermal welding to the membrane. The remaining part of the l ère face of the support layer of 1 er element of the reinforcing edge will be intended to be fixed on a device on the perimeter of a pressure balancing opening with which it is provided.

[0091] Furthermore, in these two embodiments described just above, the entire l ère face of the support layer of 2 ème element of the reinforcing edge may be fixed by thermal welding on the perimeter of a pressure balancing opening of a device and, where appropriate, the remaining part of the l ère face of the support layer of 1 erThe reinforcement edge element can be fixed by thermal welding around the edge of the pressure balancing opening of the device.

[0092] In these embodiments of the invention, the thermal welds may be performed by methods such as ultrasonic or laser welding.

[0093] The method of manufacturing the pressure balancing membrane according to the invention is perfectly within the reach of those skilled in the art.

[0094] The invention also relates to a device comprising a surface which comprises a pressure balancing opening, said opening being covered with a pressure balancing membrane according to the invention as described above.

[0095] The device can be chosen from waterproof housings of earthmoving equipment, road construction equipment, cranes, forklifts, tractors, electric charging stations, wind turbines, solar panels, containers for maritime transport, boats, car headlights or spotlights for external use.

[0096] In embodiments of the invention wherein the membrane is bilayer and comprises a l ère microporous film layer of polymer material as described above and a 2 ème layer of textile material as described above which is fixed on said l ère microporous film layer of polymeric material, preferably, and contrary to what is customary and therefore known from the prior art, the l ère layer of microporous film of polymer material is preferably opposite the confined space of the device (in other words the 2 èmelayer of textile material is in contact with the external environment). This has the advantage of preserving the ère layer of microporous film of polymer material from external aggressions (for example gravel, insects) which are likely to deteriorate and / or tear it off.

[0097] The invention also relates to a method for protecting a pressure balancing opening opening into a confined space of a device according to the invention as described above, which is characterized in that a pressure balancing membrane according to the invention as described above is fixed around the entire periphery of said opening.

[0098] The invention will be better understood with the aid of the detailed description which is set out below with reference to the appended drawing representing, by way of non-limiting example, an embodiment of a balancing membrane according to the invention.

[0099] [Fig. 1] Figure 1 is a perspective and exploded view of a pressure balancing membrane according to the invention.

[0100] [Fig. 2] Figure 2 is a top view of said pressure balancing membrane according to the invention.

[0101] [Fig. 3] Figure 3 is a sectional view along axis III-III of Figure 2 of said pressure balancing membrane according to the invention.

[0102] Figures 1 to 3 show a pressure balancing membrane 11 according to the invention which comprises: - a membrane 1 marketed under the trade name “Q.BV657D” by the company PARKER. This is a two-layer membrane comprising a layer of PTFE polymer material film with a thickness of 15 μm onto which a layer of polyamide textile material with a thickness of 100 μm has been bonded; - a reinforcing edge 4.

[0103] Membrane 1 has a rectangular shape with a length of 35 mm and a width of 15.5 mm.

[0104] Reinforcing border 4 includes a 1 er element 5 and a 2 ème element 6 which are configured to sandwich said membrane 1 around its entire periphery.

[0105] The 2nd ème element 6 of the reinforcing edge 4 is intended to be fixed on a device (not shown in the figures) so that the pressure balancing membrane 11 covers a pressure balancing opening (not shown in the figures). The 1 er element 5 of the reinforcing edge 4 is intended to be in contact with the environment external to said device.

[0106] The 1st er and the 2 ème elements (5,6) of the reinforcing edge 4 each have the shape of a frame whose opening has a shape similar to the perimeter of the membrane 1.

[0107] More precisely, the 1er element 5 has the shape of a rectangular frame with the following dimensions: - the external dimensions of the frame are a length of 40 mm and a width of 19.5 mm; - the internal dimensions of the frame are a length of 32 mm and a width of 11.5 mm.

[0108] The 2nd ème element 6 has the shape of a rectangular frame with the following dimensions: - the external dimensions of the frame are a length of 40 mm and a width of 19.5 mm; - the internal dimensions of the frame are a length of 30 mm and a width of 9.5 mm.

[0109] Given these dimensions, there is an overlap of: - 2 mm in the width direction and 1.5 mm in the length direction between the 1 er element 5 and membrane 1; - 3 mm in the width direction and 2.5 mm in the length direction between the 2 ème element 6 and membrane 1.

[0110] The 1ster element 5 comprises a support layer 2 of PET with a thickness of 50 μm.

[0111] Support layer 2 of 1 er element 5 presents: - a l ère face 7 which is covered with a l ère 12 layer of acrylic adhesive with a thickness of 90 pm; - a 2 ème side 8.

[0112] The 2nd ème element 6 comprises a support layer 3 of PET with a thickness of 50 μm.

[0113] Support layer 3 of 2 ème element 6 presents: - a l ère face 9 which is covered with a 2 ème 13 acrylic adhesive layer with a thickness of 60 pm; - a 2 ème face 10 which is covered with a 3 ème 14 layer of acrylic adhesive with a thickness of 60 pm.

[0114] More precisely, the 2 èmeelement 6 is made of a double-sided adhesive material marketed under the trade name “GERGOTAPE 296X” by the company GERGONNE SAS.

[0115] The pressure balancing membrane 11 shown in Figures 1 to 3 corresponds to the IQ1 membrane used in the experiments described below.

[0116] EXPERIMENTAL PART:

[0117] Experiments were carried out on pressure balancing membranes according to the invention and comparative ones in order to demonstrate the advantages and benefits provided by the pressure balancing membranes according to the invention.

[0118] The 7 pressure balancing membranes according to the invention (IQ1 to IQ7) had the following characteristics.

[0119] The l ère membrane according to the invention IQ.1 corresponded to the membrane shown in Figures 1 to 3 and which was described above.

[0120] The 2 èmepressure equalization membrane according to the invention IQ2 differed from the IQ1 membrane only in that the membrane was a membrane marketed under the trade name "M100WL" by the company BERGHOF. It was a two-layer membrane with a total thickness of 140 μm which comprised a layer of PTFE onto which a layer of non-woven textile material made of PET was bonded.

[0121] The 3 ème pressure balancing membrane according to the invention IQ3 differed only from the IQ1 membrane in that the membrane was a membrane marketed under the trade name "EN0711066" by the company DONALDSON. It was a two-layer membrane with a total thickness of 170 μm which included a layer of PTFE onto which a layer of non-woven PET textile material was bonded.

[0122] The 4 èmepressure balancing membrane according to the invention IQ.4 differed from membrane IQ.1 only in that the membrane was a membrane marketed under the trade name "EN0701435" by the company DONALDSON. It was a two-layer membrane which comprised a 50 μm thick PTFE layer onto which was bonded a 200 μm thick layer of polyamide non-woven textile material.

[0123] Thus, the pressure-balancing membranes IQ.1 to IQ4 all had two-layer membranes and had the same dimensions with regard to the membrane and the reinforcing edge.

[0124] The 5 ème pressure balancing membrane according to the invention IQ.5 differed from the membrane IQ.1 in that: - the membrane was a single-layer membrane marketed under the trade name “MV72040” by the company MICROVENT. It was a single-layer PTFE membrane with a thickness of 200 μm; - the 2nd ème The element of the reinforcing edge was a double-sided adhesive material marketed under the trade name “TESA 4965” by the company TESA.

[0125] More precisely, the said 2 ème element included a 12 μm thick PET support layer and featured: - a l ère face which was covered with a layer of acrylic adhesive with a thickness of 97 μm; - a 2 ème face which was covered with a layer of acrylic adhesive with a thickness of 97 pm.

[0126] The dimensions of the 5 ème pressure balancing membrane according to the invention IQ.5 were as follows: - the membrane had a rectangular shape with a length of 40 mm and a width of 19.5 mm, - the 1 er The reinforcing edge element had the shape of a rectangular frame, the external dimensions of which were 48 mm long and 27.5 mm wide, and the internal dimensions of which were 32 mm long and 32.5 mm wide. width of 11.5 mm; - the 2nd ème The reinforcing edge element had the shape of a rectangular frame, the external dimensions of which were 40 mm long and 19.5 mm wide, and the internal dimensions of which were 30 mm long and 9.5 mm wide.

[0127] Given these dimensions, there was an overlap of: - 4 mm in the width direction and 4 mm in the length direction between the 1 er element of the reinforcing edge and the membrane; - 5 mm in the width direction and 5 mm in the length direction between the 2 ème element of the reinforcing edge and the membrane.

[0128] The 6 ème pressure balancing membrane according to the invention IQ.6 differed from the IQ.5 membrane in that: - the membrane was a 150 μm thick PTFE monolayer membrane; - the 2nd ème element of the reinforcing border was a double-sided adhesive material, the assembly consisting of this membrane and this 2 ème element was marketed under the trade name “AVS 9” by the GORE company.

[0129] More precisely, the 2 ème element had a total thickness of 140 pm and included a support layer which had: - a l ère face which was covered with a layer of silicone adhesive; - a 2 ème face which was covered with a layer of silicone adhesive.

[0130] The 7 ème pressure balancing membrane according to the invention IQ.7 differed from the IQ.5 membrane in that: - the membrane was a membrane marketed under the trade name “M40W” by the company BERGHOF. It was a single-layer PTFE membrane with a thickness of 300 μm; - the 2nd ème The reinforcing edge element was made from the same double-sided adhesive material as that of the IQ.1 to IQ.4 membranes (namely the double-sided adhesive material marketed under the trade name “GERGOTAPE 296X” by the company GERGONNE SAS).

[0131] Thus, the IQ.5 to IQ.7 pressure equalization membranes all consisted of single-layer membranes and had the same dimensions with regard to the membrane and the reinforcing edge.

[0132] The 11 comparative pressure-balancing membranes (Cl to Cil) had the following characteristics.

[0133] The l ère comparative pressure equalization membrane Cl differed from the l ère pressure balancing membrane according to the invention IQ.1 in that it did not have a reinforcing edge. It only comprised the same membrane as that of the pressure balancing membrane IQ.1 but with different dimensions (namely a length of 40 mm and a width of 19.5 mm) and a means of attachment to a device. This means of attachment was identical to the 2 ème element of the reinforcing edge of the pressure balancing membrane according to the invention IQ.1. It therefore had the shape of a rectangular frame whose external dimensions corresponded to the dimensions of the membrane and was fixed around the entire perimeter of said membrane.

[0134] The 2 èmecomparative pressure equalization membrane C2 differed from 2 ème pressure balancing membrane according to the invention IQ2 in that it did not include a reinforcing edge. It only included the same membrane as that of the pressure balancing membrane IQ2 but with different dimensions (namely a length of 40 mm and a width of 19.5 mm) and a means of attachment to a device. This means of attachment was identical to the 2 ème element of the reinforcing edge of the pressure balancing membrane according to the invention IQ2. It therefore had the shape of a rectangular frame whose external dimensions corresponded to the dimensions of the membrane and was fixed around the entire perimeter of said membrane.

[0135] The 3 ème comparative pressure equalization membrane C3 differed from 3 èmepressure balancing membrane according to the invention IQ3 in that it did not include a reinforcing edge. It only included the same membrane as that of the pressure balancing membrane IQ3 but with different dimensions (namely a length of 40 mm and a width of 19.5 mm) and a means of attachment to a device. This means of attachment was identical to the 2 ème border element of reinforcement of the pressure balancing membrane according to the invention IQ.3. It therefore had the shape of a rectangular frame whose external dimensions corresponded to the dimensions of the membrane and was fixed around the entire perimeter of said membrane.

[0136] The 4 ème comparative pressure balancing membrane C4 differed from 4 èmepressure balancing membrane according to the invention IQ.4 in that it did not have a reinforcing edge but only comprised the same membrane as that of the pressure balancing membrane IQ4 but with different dimensions (namely a length of 40 mm and a width of 19.5 mm) and a means of attachment to a device. This means of attachment was identical to the 2 ème element of the reinforcing edge of the pressure balancing membrane according to the invention IQ.4. It therefore had the shape of a rectangular frame whose external dimensions corresponded to the dimensions of the membrane and was fixed around the entire perimeter of said membrane.

[0137] The 5 ème comparative pressure equalization membrane C5 differed from 5 èmepressure balancing membrane according to the invention IQ.5 in that it did not have a reinforcing edge but only comprised the same membrane as that of the pressure balancing membrane IQ.5 and a means of attachment to a device. This means of attachment was identical to the 2 ème element of the reinforcing edge of the pressure balancing membrane according to the invention IQ.5. It therefore had the shape of a rectangular frame whose external dimensions corresponded to the dimensions of the membrane and was fixed around the entire perimeter of said membrane.

[0138] The 6 ème comparative pressure balancing membrane C6 differed from 6 èmepressure balancing membrane according to the invention IQ6 in that it did not have a reinforcing edge but only comprised the same membrane as that of the pressure balancing membrane IQ6 and a means of attachment to a device. This means of attachment was identical to the 2 ème element of the reinforcing edge of the pressure balancing membrane according to the invention IQ6. It therefore had the shape of a rectangular frame whose external dimensions corresponded to the dimensions of the membrane and was fixed around the entire perimeter of said membrane.

[0139] The 7 ème comparative pressure balancing membrane C7 differed from 7 èmepressure balancing membrane according to the invention IQ.7 in that it did not include a reinforcing edge. It only included the same membrane as that of the pressure balancing membrane IQ.7 and a means of attachment to a device. This means of attachment was identical to the 2 ème element of the reinforcing edge of the pressure balancing membrane according to the invention IQ.7. It therefore had the shape of a rectangular frame whose external dimensions corresponded to the dimensions of the membrane and was fixed around the entire perimeter of said membrane.

[0140] The 8 ème comparative pressure equalization membrane C8 differed from the l ère pressure balancing membrane according to the invention IQ1 in that: - the dimensions of the membrane were different (namely a length of 40 mm and a width of 19.5 mm); - the internal dimensions of the frame of the 2 èmeelement were different (namely a length of 32 mm and a width of 11.5 mm).

[0141] The 9 ème comparative pressure equalization membrane C9 differed from 2 ème pressure balancing membrane according to the invention IQ2 in that: - the dimensions of the membrane were different (namely a length of 40 mm and a width of 19.5 mm); - the internal dimensions of the frame of the 2 ème element were different (namely a length of 32 mm and a width of 11.5 mm).

[0142] The io ème comparative pressure equalization membrane CIO differed from the 3 ème pressure balancing membrane according to the invention IQ3 in that: - the dimensions of the membrane were different (namely a length of 40 mm and a width of 19.5 mm); - the internal dimensions of the frame of the 2 èmeelement were different (namely a length of 32 mm and a width of 11.5 mm).

[0143] The n ème comparative pressure balancing membrane Cil differed from the 5 ème pressure balancing membrane according to the invention IQ5 in that the 1 er element of the The reinforcing edge had the shape of a rectangular frame, the external dimensions of which were 40 mm long and 19.5 mm wide, and the internal dimensions of the frame were 30 mm long and 9.5 mm wide.

[0144] Thus, the balancing membranes according to the invention IQ.1 to IQ.4 all comprised a membrane with a surface area of ​​542.5 mm 2 whereas the comparative balancing membranes Cl to C4 all had a membrane with a surface area of ​​780 mm 2. These balancing membranes according to the invention IQ.1 to IQ.4 had the advantage of containing less PTFE than the corresponding comparative balancing membranes C1 to C4.

[0145] Comparative pressure-balancing membranes C8 to C11 were pressure-balancing membranes in which the 1 er element and the 2 ème element sandwiched the membrane flush around its entire periphery. Thus, the pressure-balancing membranes C8 to C11 had a configuration similar to that of the ventilation device described in US Patent 9,875,733 B2 cited above.

[0146] Test No. 1 carried out with bilayer membranes IQ.1 to IQ4, Cl to C4 and C8 to CIO

[0147] The pressure balancing membranes IQ1 to IQ4, Cl to C4 and C8 to CIO were stressed under a water jet from a KARCHER® high-pressure cleaner to evaluate the gain in delamination resistance of the membranes according to the invention compared to the comparative membranes.

[0148] The pressurized water jet simulated drastic conditions to which pressure equalization membranes can be subjected, such as severe weather.

[0149] 24 hours before the test, the pressure balancing membranes under test were applied to a 400 mm long solid raw aluminum plate. The plate was positioned so as to form an angle of 150° with the water jet of the high-pressure cleaner set to a pressure of 210 bars and setting the distance between the nozzle of the said cleaner and the plate at 50 cm. The water jet thus struck the membranes under test.

[0150] The tests were carried out for a maximum duration of 2 minutes. However, test No. 1 was stopped as soon as the entire pressure-balancing membrane under test was destroyed. The water jet was moved from left to right throughout the test in order to stress the membranes under test. The nozzle movement speed was 5 back and forth movements per minute.

[0151] Test No. 2 carried out with monolayer membranes IQ.5 to IQ.7, C5 to C7 and Cil

[0152] The course of the 2 ème test was identical to that of the 1 er test except that the criticality of the test has been increased.

[0153] In fact, the aluminum plate was positioned so as to form an angle of 150° with the water jet of the high-pressure cleaner set at a pressure of 210 bars and by setting the distance between the nozzle of said cleaner and the plate at 35 cm (and no longer 50 cm). The water jet thus struck the membranes tested.

[0154] The tests were carried out for a maximum duration of 2 minutes. However, test No. 2 was stopped as soon as the entire pressure-balancing membrane under test was destroyed. The water jet was moved from left to right throughout the test in order to stress the membranes under test. The nozzle movement speed was 5 back and forth movements per minute.

[0155] Table 1 below details the results obtained with all the pressure-balancing membranes tested. More specifically, for each membrane tested, the duration of resistance to water under pressure and its condition after stopping the test are indicated.

[0156] For pressure equalization membranes comprising a two-layer membrane, the 2 ème column of table 1 indicates: - “Polymer” when the microporous film layer of polymeric material (i.e. PTFE) of the membrane was exposed to the high pressure water jet; - “Textile” when the textile material layer (i.e. polyamide or PET) of the membrane was exposed to the high-pressure water jet.

[0157] Thus, for the IQ.1, IQ.2, Cl and C2 membranes, both possible configurations were tested. In the last column of Table 1, the following terms are understood: - “cohesive failure of the adhesive on [...]% of the surface”: at the end of the test, the pressure-balancing membrane tested was detached from the aluminum plate on [...]% of the surface and part of the adhesive was found on the aluminum plate; - “adhesive rupture between the membrane and the adhesive on [...]% of the surface”: at the end of the test, the pressure-balancing membrane tested was detached from the aluminum plate on [...]% of the surface and all the adhesive remained on the 2 ème element of the reinforcing edge. Table 1 detailing the results obtained with all pressure balancing membranes tested on their holding time and the condition of the membrane after stopping the test

[0158] In view of the results detailed in Table 1 above, the following remarkable points can be noted: - Unlike pressure balancing membranes C1 to C4, the pressure balancing membranes according to the invention IQ.1 to IQ4 all remain intact after 2 minutes of test no. 1. They are not damaged when subjected to the pressurized water jet. - As for the pressure balancing membrane IQ1, the latter remains intact in the configuration in which the textile material is exposed to the pressurized water jet. Indeed, in the configuration in which the PTFE film is exposed to the pressurized water jet, this PTFE layer is torn off over 40% of the membrane surface. This experiment demonstrates that it may be more advantageous for the balancing membranes according to the invention to expose the textile material layer to the external environment. - As for the IQ.2 pressure balancing membrane, the latter remains intact whatever the configuration, i.e. regardless of whether the textile material (PET) or the microporous film of polymer material (PTFE) of the membrane is exposed to the pressurized water jet. - Test #2 was more drastic (reduced nozzle-aluminum plate distance). However, The pressure-balancing membranes according to the invention IQ.5 to IQ.7 all withstood the pressurized water jet better than the comparative membranes C5 to C7. The IQ.5 membrane remained intact at the end of the test. - Comparing the results of the IQ.6 and C6 membranes, the IQ.6 membrane has a longer protection time (120 s versus 80 s) and is less damaged at the end of test no. 2 (the cohesive failure of the adhesive occurred on 50% of the surface versus 100% of the surface for the C6 membrane). - Comparative pressure balancing membranes C8 to CIO are all damaged when subjected to pressurized water jet. - The comparative pressure balancing membrane Cil did not withstand the pressurized water jet.

[0159] These experimental results demonstrate the better robustness and reliability of the pressure balancing membranes according to the invention in comparison with comparative pressure balancing membranes which are devoid of a reinforcing border or in which the 1 er element and the 2 ème element of the reinforcing edge are located flush with the membrane as is the case in the ventilation device described in US patent 9,875,733 B2.

[0160] Furthermore, as recalled above, some of the pressure balancing membranes according to the invention (namely IQ.1 to IQ4) had the advantage of comprising less PTFE than the corresponding comparative pressure balancing membranes (namely C1 to C4). They therefore had a reduced environmental impact and were more economical.

Claims

CLAIMS 1. Pressure balancing membrane (11) comprising a membrane (1) and a reinforcing edge (4), part or all of the periphery of said membrane (1) is sandwiched with said reinforcing edge (4) which comprises a 1 er element (5) and a 2 ème element (6), the 1 er element (5) and 2 ème element (6) each comprise a support layer (2,3), the support layer (2) of the 1 er element (5) has a l ère face (7) and a 2 ème face (8), the support layer (3) of the 2 ème element (6) has a l ère face (9) and a 2 ème face (10), characterized in that: - part of the 2 ème face (10) of the support layer (3) of the 2 ème element (6) is fixed on a part of the l ère face (7) of the support layer (2) of the 1 er element (5), the remaining part of the 2 ème face (10) of the support layer (3) of the 2ème element (6) is fixed on a part of the membrane (11), as well as the remaining part of the l ère face (7) of the support layer (2) of the 1 er element (5) is fixed on a part of the membrane (11) or - the entire 2 ème face (10) of the support layer (3) of the 2 ème element (6) is fixed on the membrane (11) and part of the l ère face (7) of the support layer (2) of the 1 er element (5) is fixed on the membrane (11).

2. Pressure balancing membrane (11) according to claim 1, characterized in that the membrane (1) is a single-layer microporous film of polymer material which is selected from polytetrafluoroethylene (hereinafter abbreviated as "PTFE"), polychlorotrifluoroethylene (hereinafter abbreviated as "PCTFE"), polyvinyl fluoride (hereinafter abbreviated as "PVF"), polysiloxane, polycarbonate (hereinafter abbreviated as "PC") and polyester.

3. Pressure balancing membrane (11) according to claim 1, characterized in that the membrane (1) is bilayer and comprises a l ère microporous film layer of polymer material selected from PTFE, PCTFE, PVF, polysiloxane, PC and polyester and a 2 ème layer of textile material which is fixed on said l ère layer of microporous film of polymer material, said textile material being chosen from textiles based on polyethylene terephthalate (hereinafter abbreviated as “PET”), polyamides, polypropylene, polyethylene, acrylic, PTFE, elastane, glass fibers, carbon or cellulose.

4. Pressure balancing membrane (11) according to any one of claims 1 to 3, characterized in that the 1 er and the 2 èmeelements (5,6) of the reinforcing edge (4) each have the shape of a frame whose opening has a shape similar to the perimeter of the membrane (1).

5. Pressure balancing membrane (11) according to any one of claims 1 to 4, characterized in that the material of the support layer (2, 3) of the 1 er element (5) and 2 ème element (6) is selected from PET, poly(ethylene naphthalate) (abbreviated "PEN"), polyvinyl chloride (abbreviated "PVC"), polyamide, polypropylene and metal foil, the material of the support layer (2) of the 1 er element (5) being identical to or different from the material of the support layer (3) of the 2 ème element (6).

6. Pressure balancing membrane (11) according to any one of claims 1 to 5, characterized in that: - the l ère face (7) of the support layer (2) of the 1 er element (5) is covered with an adhesive (12), - the 2 ème face (10) of the support layer (3) of the 2 ème element (6) is covered with an adhesive (14).

7. Pressure balancing membrane (11) according to claim 6, characterized in that the l ère face (9) of the support layer (3) of the 2 ème element (6) is covered with an adhesive (13).

8. Pressure balancing membrane (11) according to any one of claims 6 to 7, characterized in that the adhesive (12, 13, 14) is chosen from pressure-sensitive adhesives, preferably adhesives based on acrylics, silicone, rubber or polyurethane.

9. A device comprising a surface which comprises a pressure balancing opening, said opening being covered with a pressure balancing membrane (11) according to any one of claims 1 to 8.

10. Device according to claim 9, characterized in that it is chosen from the waterproof housings of earthmoving machines, road construction machines, cranes, forklifts, tractors, electric charging stations, wind turbines, solar panels, containers for maritime transport, boats, car headlights or projectors for external use.

11. Method for protecting a pressure balancing opening opening into a confined space of a device according to claim 9 or 10, characterized in that a pressure balancing membrane (11) according to any one of claims 1 to 8 is fixed around the entire periphery of said opening.

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