Tank for storing a fluid under pressure

Abstract

The invention relates to a method for manufacturing a tank, in particular for storing a pressurized fluid, comprising an elongated and consolidated textile element, said method comprising the steps of: (i) Manufacturing an elongated and unconsolidated textile preform by means of a specific device (1), said preform being manufactured according to a method comprising the steps of: Implementing the feed means (6) on each of the modules (4), said feed means (6) comprising selected ribbons (10), said selected ribbons (10) comprising at least thermoplastic composite ribbons; Setting the feed speed V1 and the rotation speed V2 of each of the modules (4) and starting up each module (4), Cutting the elongated element (11) and / or exhausting the ribbons (10), and Recovering the unconsolidated elongated textile preform (11) obtained;(ii) Consolidation of the textile preform obtained in the previous step, by heating and cooling the thermoplastic composite ribbons, whereby the preform is consolidated and an elongated and consolidated textile element is obtained. Figure for abstract: Fig. 1;

Description

Title of the invention: Tank for storing a fluid under pressure Field of invention

[0001] The invention relates to a tank for storing a fluid under pressure, in particular hydrogen, comprising an elongated textile element, and its manufacturing method. Technical background

[0002] The invention relates to a tank comprising a specific elongated textile element for the storage of gas, in particular high-pressure compressed gas, and its manufacturing method.

[0003] One of the goals sought in the field of transport, and particularly in the automotive field, is to offer vehicles that are less and less polluting. Thus, electric or hybrid vehicles with a battery aim to gradually replace thermal vehicles, such as gasoline or diesel vehicles. However, it turns out that the battery is a relatively complex component of the vehicle. Depending on the location of the battery in the vehicle, it may be necessary to protect it from impacts and from the external environment, which may be at extreme temperatures and variable humidity. It is also necessary to avoid any risk of flames.

[0004] In addition, the batteries of electric or hybrid vehicles usually represent between 10 and 30% of the vehicle's weight. This excess weight leads to a number of disadvantages, including in particular excess fuel or energy consumption.

[0005] Furthermore, it is important that its operating temperature does not exceed 55°C so as not to damage the battery cells and preserve its lifespan. Conversely, for example in winter, it may be necessary to raise the temperature of the battery in order to optimize its operation.

[0006] Furthermore, the electric vehicle still suffers today from several problems, namely the autonomy of the battery, the use in these batteries of rare earths, the resources of which are not inexhaustible as well as a problem of electricity production in the different countries to be able to recharge the batteries.

[0007] Hydrogen therefore represents an alternative to the electric battery, since hydrogen can be transformed into electricity using a fuel cell and thus power electric vehicles.

[0008] However, the storage of hydrogen is technically difficult and expensive due to its very low molar mass and its very low liquefaction temperature, all particularly when it comes to mobile storage. However, to be effective, storage must be carried out in small volumes, which requires maintaining the hydrogen under high pressure, given the operating temperatures of the vehicles. This is the case, in particular, for hybrid fuel cell road vehicles for which the aim is for a range of around 600 to 700 km, or even less for mainly urban uses in addition to an electric battery base.

[0009] Hydrogen tanks are generally made of a metallic or polymeric envelope (also called a liner), which must prevent the diffusion of hydrogen outside the envelope. This first envelope must itself be protected by a second envelope (generally made of composite materials) intended to withstand the internal pressure of the tank (for example, 700 bars) and resistant to possible shocks or heat sources. Furthermore, the tank includes a valve system, which must also be safe.

[0010] According to the Hydrogen Memento of the French Association for Hydrogen and Fuel Cells (AFHYPAC) Sheet 4.2, revised December 2016, the storage and distribution of hydrogen under pressure has been standard practice for many years, with cylinders or assemblies of cylindrical cylinders, made of steel, inflated to 20 or 25 MPa (types I and II) or metal reinforced by a winding of fibrous materials, externally. The disadvantage of this storage method is the size - only 14 kg / m3 under 20 MPa and at ordinary temperature (21°C) compared to 100 kg / m3 for methane - and especially the weight, which results from the use of steels with low stress levels to avoid problems of embrittlement by hydrogen. The situation has radically changed with the appearance of the technology of so-called type IV composite tanks.Their basic principle is to separate the two essential functions of sealing and mechanical strength to manage one independently of the other. In this type of tank, a thermoplastic resin bladder called a liner or sealing sheath is associated with a reinforcing structure made of fibers (glass, aramid, carbon) impregnated with thermosetting resin, called a sheath or reinforcement layer. This type of tank allows working at much higher pressures while reducing the mass of the tank and avoiding the risk of explosive rupture in the event of severe external aggression. This is why a pressure of 70 MPa (700 bars) has practically become the current standard.

[0011] In type IV tanks, the sealing layer and the reinforcing layer are made of different materials, which do not adhere to each other, often responsible for the collapse of the sealing layer, when simultaneously, on the one hand, there is an accumulation of gas at the interface between the sealing layer and the reinforcing layer and on the other hand, a drop in the internal pressure of the tank. In addition, the drying of type IV tanks, which takes place after the pressure test water, is long and expensive, because it can only be done under vacuum due to the risk of collapse of the sealing layer.

[0012] This problem has given rise to the development of type V tanks, which are based on the use of the same polymer for the sealing layer and for the matrix of the reinforcement layer, or at least a polymer compatible with that making up the matrix of the composite (so-called type 4,5 tanks), so as to guarantee excellent and durable weldability between these two layers, thus making it possible to obtain a single-piece tank. This type of tank is still at the R&D stage.

[0013] It is known to produce the composite envelope to use, as a matrix for this composite, epoxy resins to manufacture tanks which can have a high glass transition temperature (hereinafter Tg), i.e. a Tg greater than 100°C. The disadvantage of these composites based on thermosetting resins, in particular of the epoxy type, is that they are generally microcracked, after curing the thermosetting resin, or even after having undergone a certain number of pressure / vacuum cycles, induced by the filling / emptying cycles, which causes great variability, or even a loss of mechanical strength. In anticipation of this drop in performance over time, it is therefore necessary to increase the carbon fiber content and therefore the weight and cost of the tank.

[0014] Furthermore, in the case of thermosetting resins, particularly epoxy resins, microcracking impairs the impermeability of the composite reinforcement, which requires the use of a thick sealing layer inside the tank (i.e. type IV tank).

[0015] Finally, in terms of recyclability, current type IV tanks use reinforcement layers made of thermosetting resins, particularly epoxy, which are not recyclable.

[0016] However, despite the improvements made to type IV tanks, they still have drawbacks. In particular, it is sought to accelerate the filling speed of the tank. However, the temperature resistance of gas tanks, particularly hydrogen tanks, is too low with current solutions. Accelerating the filling speed of the tank would be an advantage, particularly economical for the consumer, especially without having to additionally cool the hydrogen to -60°C before filling.

[0017] The use of a reinforcing layer of polyphthalamide (hereinafter referred to as PPA) with a high glass transition temperature (hereinafter Tg) would be a significant advantage in terms of mechanical strength at high temperatures. In addition, since this type of resin is thermoplastic, it would make it possible to obtain an easily recyclable tank. The thermoplastic nature of the resin would make it possible to reduce the level of microcracking of the composite envelope, thus reinforcing its mechanical strength and reducing the variability of this mechanical strength, which would make it possible to significantly reduce the amount of carbon fiber used and therefore the cost and carbon footprint of the Type V tank compared to those of Type IV. In addition, the semi-crystalline nature of the resin would increase its impermeability to gases, particularly hydrogen. Consequently, the composite envelope would contribute to the impermeability of the tank and thus make it possible to reduce the thickness of the sealing layer and therefore the cost and weight of the sealing layer internal to the tank.

[0018] However, the manufacture of this type of tank by hot winding of composite tapes onto a thermoplastic polymer sealing layer poses difficulties, linked to the appearance of significant residual stresses of thermal origin, inherent in the differential expansions of the materials involved, in particular inherent in the differential expansions between the fibers and the polymer composing the sealing layer, during cooling of the tank, at the end of its manufacture. This is particularly exacerbated in the case of a PPA matrix composing the carbon fiber-based composite reinforcement. Indeed, the high processing temperature of the PPA-based composite tape, due to the high melting point of this type of resin, as well as its high Tg, are the main sources responsible for the additional residual stresses in the tank.When the tank comprises inserts molded in aliphatic polyamide resin, of low Tg, typically of Tg of the order of 50°C, said residual stresses can lead to deformation of the inserts, preventing the complete manufacture of the tank and in particular the fixing of the bases closing the tank. When the tank is of type V (or 4.5, that is to say that the polymer composing the matrix of the composite is of a different nature from that of the sealing layer, but the two polymers remain compatible and weldable together) and that it comprises a sealing layer of polyamide of low Tg, in particular of aliphatic polyamide type, the residual stresses can lead to decohesion within the composite reinforcement layer itself.

[0019] Furthermore, the manufacturing processes for these composite tanks are generally slow and expensive. Thus, conventionally based on wet filament winding or hot winding of thermoplastic composite ribbons, the manufacture of a single-piece composite tank, of 60 liters or more, requires cycle times of several hours. In addition, these processes prove to be inefficient below a certain tank size, typically below 30 liters. Finally, the quality of the composite obtained is imperfect, due to the presence of porosities, linked to the low pressure applied during the implementation of the fibers pre-impregnated with resin, when it is a question of wet impregnation or during the in situ consolidation of the thermoplastic composite ribbons.

[0020] Thus, the usual manufacturing processes for these composite tanks do not allow not the easy and efficient preparation of conformable composite tanks, i.e. tanks that can be inserted into volumes of complex and / or narrow shape, in at least one of the three dimensions, such as, for example, the volume of a battery pack. One of the most promising types of conformable tank is composed of an assembly of small diameter composite tubes (typically with a diameter < 200mm) connected to each other by pipes. However, as indicated previously, current processes allow the manufacture of single-piece tanks, typically 60 liters, which are therefore very bulky and at least impossible to insert into a battery pack, but are not suitable for the manufacture of tubular tanks of small diameters.

[0021] Consequently, a simple, rapid and inexpensive process is currently being sought to provide tanks with good mechanical strength at high temperatures, which are recyclable and conformable, and which have good gas tightness. These tanks would thus make it possible to store hydrogen but also any type of gas under pressure, and in particular under high pressure.

[0022] Consequently, today there is a need for tanks that have good mechanical strength at high temperatures, are recyclable and conformable, have good gas tightness, and are easy to manufacture. These tanks would thus make it possible to store hydrogen but also any type of gas under pressure, and in particular under high pressure. Summary of the invention

[0023] This problem is solved by the method of the invention which comprises two stages: - A first stage i) of manufacturing an elongated and unconsolidated textile preform, comprising several layers of thermoplastic composite ribbons, each layer comprising a ribbon wound at a given angle, without embedding, said preform being capable of being obtained from a specific device, represented in [Fig.l]; - A second consolidation step ii) of the textile preform obtained in the previous step, in particular under pressure.

[0024] This process has many advantages.

[0025] First of all, unlike processes involving braiding or weaving and which require going over the same layer to stack several layers of woven or braided ribbons, the manufacture of the preform according to step i) of the process of the invention can be carried out continuously, and therefore allows rapid and inexpensive access to textile preforms of large dimensions, in particular of small diameter with great lengths.

[0026] Furthermore, step i) of the method according to the invention makes it possible to superimpose a very large number of layers: the preform can contain as many layers of ribbon as there are modules implemented.

[0027] The device implemented in step i) uses guides to deploy the ribbons in the same direction. It thus makes it possible to produce elongated textile preforms of different shapes, cylindrical or not. The preform obtained according to step i) can also include section restrictions, at which certain ribbons can be cut and welded, and inserts positioned, in particular before consolidation. Similarly, the preform can be easily bent at room temperature in order to give it a particular non-rectilinear shape which can then be fixed during the consolidation step ii). This will however require a particular choice of the fiber orientations in the different layers of the preform. Thus, the method makes it possible to easily access conformable reservoirs, which can in particular be inserted into a volume similar to a battery pack of an automobile.

[0028] Advantageously, step ii) makes it possible to co-consolidate, within a single step, thermoplastic or metallic inserts, with the ribbons of the textile preform, making it possible in particular to close the tube to make it a reservoir, which constitutes an additional economic advantage of the method for manufacturing reservoirs according to the invention. In addition, this co-consolidation makes it possible to improve the mechanical strength and / or the cohesion between the insert and the co-consolidated elongated textile element.

[0029] The invention thus relates, according to a first aspect, to a method of manufacturing a tank, in particular for storing a fluid under pressure, comprising an elongated textile and consolidated element, said method comprising the steps of:

[0030] (i) Manufacture of an elongated textile and unconsolidated preform by means of a device (1) comprising:

[0031] - a frame (2) comprising a main longitudinal guide (3) in a direction X, said guide (3) being fixed on the frame (2) and

[0032] - at least two modules (4) arranged in series around the guide (3) in the direction X, each module (4) comprising:

[0033] - a feed ring (5) surrounding a section of the guide (3),

[0034] - supply means (6) arranged on the crown (5) capable of supplying at at least one ribbon (10) towards the guide (3) at a winding angle of between -90° and 90° with the direction X and at a feed rate VI, each ribbon (10) being capable of winding at least around the guide (3) or on the upper layer of ribbon (10), and

[0035] - drive means (15) of the crown (5) capable of rotating the crown (5) around the guide (3) at a rotation speed V2,

[0036] Said preform being manufactured according to a method comprising the steps of: - Implementation of the supply means (6) on each of the modules (4), said supply means (6) comprising selected ribbons (10), said selected ribbons (10) comprising at least thermoplastic composite ribbons - Setting the feed speed VI and the rotation speed V2 of each of the modules (4) and starting up each module (4), - Cutting of the elongated element (11) and / or exhaustion of the ribbons (10), and - Recovery of the unconsolidated elongated textile preform (11) obtained;

[0037] (ii) Consolidation of the textile preform obtained in the previous step,

[0038] by heating and cooling the thermoplastic composite ribbons, whereby the preform is consolidated and an elongated and consolidated textile element is obtained.

[0039] In embodiments, the method according to the invention comprises one or more of the following additional features: - thermoplastic composite tapes include: • Reinforcing fibers, continuous or discontinuous, of an inorganic material; and • A composition of thermoplastic polymers. - the reinforcing fibers of an inorganic material are: • impregnated to the core or pre-impregnated with a composition of thermoplastic polymers, or • mixed with thermoplastic polymer fibers. - the thermoplastic composite tape comprises continuous fibers impregnated with a composition based on a thermoplastic polymer, having a glass transition temperature (Tg), measured according to standard ISO 11357-3: 2013, greater than 80°C, preferably greater than or equal to 100°C, even more preferably greater than 120°C, when the polymer is amorphous, and a melting temperature greater than 150°C when the polymer is semi-crystalline. - the thermoplastic polymer composition of the composite tape mainly comprises a polyamide, preferably semi-crystalline. - polyamide is an aliphatic, cycloaliphatic or semi-aromatic polyamide. - the aliphatic polyamide is chosen from PA 5, PA5-10, PA6, PA66, PA6-10, PA6-12, PA6-18, PA9, PA10-10, PA 10-12, PAU, PA12, and their mixture. - the semi-aromatic polyamide is chosen from PA MPMDT / 6T, PA 11 / 6T, PA 11 / 10T, PA 11 / BACT, PA 5T / 10T, PA 11 / 6T / 10T, PA MXDT / 4T, PA MXDT / 6T, PA MXDT / 10T, PA MPMDT / 4T, PA MPMDT / 6T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA BACT / 4T, PA BACT / 10T / 6T, PA 11 / BACT / 4T, PA 11 / BACT / 6T, PA 11 / BACT / 10T, PA 11 / MXDT / 4T, PA 11 / MXDT / 6T, PA 11 / MXDT / 10T, PA 11 / MPMDT / 4T, PA 11 / MPMDT / 6T, PA 11 / MPMDT / 10T, PA 11 / MXDT / 10T, PA11 / 5T / 10T, and their mixture, the fibers of the thermoplastic composite tapes are chosen from glass fibers, carbon fibers, basalt fibers or are basalt-based. the fibers of thermoplastic composite ribbons are unidirectional, that is, all oriented along the length of the ribbon. the composite tapes contain a fiber content of between 40 and 70% by volume, preferably between 50 and 60% by volume of the thermoplastic composite tapes. the selected ribbons (10) further comprise non-composite ribbons (10) of thermoplastic polymer. the non-composite thermoplastic polymer ribbons (10) represent a minority mass fraction of the preform compared to the mass fraction of the thermoplastic composite ribbons. the polymer composition constituting the non-composite thermoplastic ribbons (10) mainly comprises a polyamide, preferably semi-crystalline. the thermoplastic polymer composition of the thermoplastic composite ribbons (10) on the one hand, and that of the non-composite thermoplastic polymer ribbons (10) on the other hand, are compatible, in particular identical. the ribbons (10) have a thickness of between 50 and 300 pm, in particular between 50 and 260 pm and more particularly between 60 pm and 170 pm. the ribbons (10) have a width of between 5 mm and 50 mm, in particular between 10 mm and 15 mm. the winding angle of the ribbon (10) relative to the X direction is between +90° and -90°. the wrap angle is equal to + / -54.8° to + / -10°, preferably + / -5°, more preferably + / -1°. the textile preform manufactured in step i) comprises a variation in section, in particular sequential in the X direction. step ii) is carried out in a mold, in particular external to the preform, in particular closed. step ii) pressure is applied by means of a bladder internal to the preform. - prior to step ii), an insert is positioned at the ends of the preform obtained in step i), preferably outside the ends of the preform. - the insert is made of a thermoplastic material, possibly composite. - in step ii), the insert is co-consolidated to the ribbons (10) during consolidation step ii).

[0040] According to a second aspect, the invention relates to a tank, in particular for the storage of a fluid under pressure, in particular hydrogen, comprising at least one elongated textile and consolidated element, capable of being obtained according to the method of the invention.

[0041] In embodiments, the reservoir according to the invention comprises one or more of the following additional features: - each consolidated elongated element is provided with an insert at its ends. - the insert is:

[0042] - an insert closing the elongated and consolidated element, or

[0043] - an insert provided with an orifice, intended to allow the entry and exit of the fluid. - the tank comprises several consolidated elongated elements, in series, connected to each other via connectors.

[0044] The inventors were able to show that the tanks comprising an elongated and consolidated textile element obtained according to the method of the invention exhibited very good mechanical resistance compared to the composite tanks of the state of the art.

[0045] Indeed, unlike conventional methods involving braiding of composite ribbons, the method of the invention allows the ribbons to be wound without weaving, which makes it possible to avoid local overstressing at the points where the fibers intersect, and therefore to improve the mechanical strength of the elongated textile element obtained after consolidation.

[0046] Advantageously, the consolidation step ii) can be carried out under pressure, in particular under a pressure of between 5 and 10 bars, which makes it possible both to further improve the mechanical resistance and to reduce the porosity of the composite material.

[0047] Indeed, conventional processes using wet filament winding or winding of thermoplastic composite ribbons do not allow high pressure to be applied, particularly for a prolonged period, so that the quality of the consolidation is often quite low.

[0048] Furthermore, the inventors were able to observe that step ii) of consolidation of the preform under pressure made it possible to give the elongated and consolidated textile element obtained, a very low residual porosity, notably less than 5%, in particular less than 2%, which makes it possible to reinforce the barrier effect played by the liner in type IV or 4.5 tanks, or even to do without a liner and obtain a type V tank.

[0049] Furthermore, according to another advantage, when the thermoplastic polymer composition constituting the composite ribbons is or comprises a semi-crystalline thermoplastic polymer, in particular polyphthalamide, the crystallization of the resin during the cooling step advantageously makes it possible to further improve the barrier effect of the reservoir with respect to the pressurized fluid.

[0050] Advantageously, the step of consolidating the preform in a closed mold also makes it possible to reduce the thermooxidation of the resin which occurs during the deposition of thermoplastic tape in the open air, and thus to contribute to the improvement of the mechanical properties of the composite tubular structure thus obtained.

[0051] According to a third aspect, the invention relates to an elongated, unconsolidated textile preform, capable of being obtained according to step i) of the method according to the invention.

[0052] According to a fourth aspect, the invention relates to a battery pack, in particular for a motor vehicle, comprising a hydrogen storage tank according to the invention.

[0053] According to a fifth aspect, the invention relates to the use of the device according to the invention, as described in particular in Figures 1 to 11, for preparing a reservoir according to the invention. Brief description of the figures

[0054] [Fig.l] is a perspective view of an example of a device according to the invention,

[0055] [Fig.2] is a perspective view from an opposite angle of the device of [Fig.l],

[0056] [Fig.3] is a perspective view of an example of an elongated element according to the invention,

[0057] [Fig.4] is a sectional view of [Fig.3],

[0058] [Fig.5] is a perspective view of an example of a module according to the invention,

[0059] [Fig.6] is a perspective view of the module of [Fig.5],

[0060] [Fig.7] is a perspective view of an exemplary ribbon feeding means according to the invention,

[0061] [Fig.8] is a perspective view of another exemplary embodiment of a device according to the invention,

[0062] [Fig.9] is a perspective view from an opposite angle of the device of [Fig.8],

[0063] [Fig. 10] is a perspective view of an elongate element comprising a variable section according to the invention, and

[0064] [Fig. 11] is a sectional view of an elongated curved element according to the invention.

[0065] It should be noted that in these figures, the common structural and / or functional elements different variants may have the same references. Detailed description

[0066] The invention is now described in more detail and in a non-limiting manner in the following description.

[0067] Unless otherwise indicated, all percentages relating to quantities are volume percentages. Process for manufacturing a tank

[0068] According to a first aspect, the invention relates to a method of manufacturing a tank, in particular for storing a fluid under pressure, comprising an elongated and consolidated textile element, said method comprising the steps of:

[0069] (i) Manufacture of an elongated textile and unconsolidated preform by means of a device (1) comprising:

[0070] - a frame (2) comprising a main longitudinal guide (3) in a direction X, said guide (3) being fixed on the frame (2) and

[0071] - at least two modules (4) arranged in series around the guide (3) in the direction X, each module (4) comprising:

[0072] - a feed ring (5) surrounding a section of the guide (3),

[0073] - supply means (6) arranged on the crown (5) capable of supplying at at least one ribbon (10) towards the guide (3) at a winding angle of between -90° and 90° with the direction X and at a feed rate VI, each ribbon (10) being capable of winding at least around the guide (3) or on the upper layer of ribbon (10), and

[0074] - drive means (15) of the crown (5) capable of rotating the crown (5) around the guide (3) at a rotation speed V2,

[0075] Said preform being manufactured according to a method comprising the steps of: - Implementation of the supply means (6) on each of the modules (4), said supply means (6) comprising selected ribbons (10), said selected ribbons (10) comprising thermoplastic composite ribbons, - Setting the feed speed VI and the rotation speed V2 of each of the modules (4) and starting up each module (4), - Cutting of the elongated element (11) and / or exhaustion of the ribbons (10), and - Recovery of the unconsolidated elongated textile preform (11) obtained;

[0076] (ii) Consolidation of the textile preform obtained in the previous step, by heating and cooling the thermoplastic composite ribbons, whereby the preform is consolidated and an elongated and consolidated textile element is obtained.

[0077] Step i)

[0078] Step i) comprises the manufacture of an elongated, unconsolidated textile preform, by means of so-called textile ribbons, more particularly thermoplastic composite ribbons. Step i) is carried out by means of a specific device described in figures 1 to 11.

[0079] For the purposes of the invention, a ribbon is said to be textile and therefore comprises fibers, for example unidirectional carbon fibers, in which case these are dry fibers. A ribbon compatible with the invention is capable of being wound around the guide and comprises a structure that is sufficiently rigid to remain wound around the guide.

[0080] [Thermoplastic composite tapes]

[0081] By "thermoplastic composite tape" is meant a tape comprising fibers of an inorganic material and a thermoplastic polymer composition, capable of melting under the effect of temperature then solidifying, and therefore consolidating the preform.

[0082] In particular, the thermoplastic composite ribbons used in step i) may comprise: - continuous or discontinuous reinforcing fibers of an inorganic material; and - a composition of thermoplastic polymers.

[0083] In embodiments, the thermoplastic composite ribbons comprise fibers of inorganic materials: - impregnated to the core with a composition of thermoplastic polymers (commonly called “tape”); or - or pre-impregnated with a composition of thermoplastic polymers, in particular in powder form, or - mixed with thermoplastic polymer fibers, and commonly called “combined ribbons”.

[0084] In preferred embodiments, the thermoplastic composite tape is a tape impregnated at the core with a thermoplastic polymer composition.

[0085] In embodiments, the thermoplastic composite ribbon comprises continuous fibers impregnated with a composition based on a thermoplastic polymer, having a glass transition temperature (Tg), measured according to the ISO 11357-3:2013 standard, greater than 80°C, preferably greater than or equal to 100°C, even more preferably greater than 120°C, when the polymer is amorphous, and a melting temperature greater than 150°C when the polymer is semi-crystalline.

[0086] In embodiments, the thermoplastic polymer composition of the composite tape predominantly comprises a polyamide, preferably semi-crystalline.

[0087] In embodiments, the polyamide is an aliphatic, cycloaliphatic or semi-aromatic polyamide.

[0088] The aliphatic polyamide may be chosen from PA 5, PA5-10, PA6, PA66, PA6-10, PA6-12, PA6-18, PA9, PA10-10, PA 10-12, PAU, PA12, and their mixture.

[0089] The semi-aromatic polyamide can be chosen from PA MPMDT / 6T, PA 11 / 10T, PA 11 / BACT, PA 5T / 10T, PA 11 / 6T / 10T, PA MXDT / 4T, PA MXDT / 6T, PA MXDT / 10T, PA MPMDT / 4T, PA MPMDT / 6T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA BACT / 4T, PA BACT / 10T / 6T, PA 11 / BACT / 4T, PA 11 / BACT / 6T, PA 11 / BACT / 10T, PA 11 / MXDT / 4T, PA 11 / MXDT / 6T, PA 11 / MXDT / 10T, PA 11 / MPMDT / 4T, PA 11 / MPMDT / 6T, PA 11 / MPMDT / 10T, PA 11 / MXDT / 10T, PA11 / 5T / 10T, and their mixture.

[0090] The fibers of the composite ribbons can be chosen from glass fibers, carbon fibers, basalt fibers or are basalt-based.

[0091] The fibers of the thermoplastic composite ribbons are preferably unidirectional, which means that in this case the fibers are all oriented in the same direction, i.e. along the length of the ribbon. The ribbons can also be composed of several layers of fibers superimposed on each other and having different orientations from one layer to another: however, even in this case, the fibers are non-woven and / or non-braided.

[0092] In embodiments, the composite ribbons contain a fiber content of between 40 and 70% by volume, preferably between 50 and 60% by volume of the material constituting the composite ribbons. This fiber percentage can be determined according to well-known methods such as those described in ISO14127:2008

[0093] In embodiments, the selected ribbons (10) further comprise non-thermoplastic polymer composite ribbons (10).

[0094] In other embodiments, the non-composite thermoplastic polymer ribbons (10) represent a minor mass fraction of the preform relative to the mass fraction of the thermoplastic composite ribbons.

[0095] In still other embodiments, the polymer composition constituting the non-composite thermoplastic ribbons (10) predominantly comprises a polyamide, preferably semi-crystalline.

[0096] In variants of the embodiments, the ribbons (10) have a thickness of between 50 and 300 μm, in particular between 50 and 260 μm and more particularly between 60 μm and 170 μm.

[0097] In variants of the embodiments, the ribbons (10) have a width of between 5 mm and 50 mm, in particular between 10 mm and 15 mm.

[0098] The ribbons are deposited towards the guide with a winding angle strictly greater than -90° relative to the direction X of advancement of the textile element and strictly less than 90° relative to the direction X of advancement of the element textile.

[0099] In other words, the winding angle of the ribbon (10) relative to the X direction is between +90° and -90°, the limits +90° and -90° not being included.

[0100] In embodiments, the wrap angle is equal to + / -54.8° to + / -10°, preferably + / -5°, more preferably + / -1°.

[0101] According to one embodiment of the invention, the method further comprises a step of varying the diameter, or the section if it is not a tube with a circular section, of the elongated element. Means other than the implementation of the secondary guide can be implemented to enlarge or reduce the diameter, or the section if it is not a tube with a circular section, of the elongated element.

[0102] The textile preform obtained at the end of step i) generally comprises several layers, in particular as many layers as there are modules (4) used. Each layer is formed by winding a ribbon, which may be of the same or different nature, to that of the ribbon of at least one adjacent layer.

[0103] Thus, the non-composite thermoplastic ribbons can in particular be interposed between two layers of thermoplastic composite ribbon and / or constitute the internal layer of the preform and therefore of the elongated textile element after consolidation. This internal layer formed by non-composite thermoplastic ribbons can in particular act as a barrier layer to the fluid contained in the reservoir.

[0104] In embodiments, the thermoplastic polymer composition of the thermoplastic composite ribbons (10), on the one hand, and that of the thermoplastic non-composite polymer ribbons (10) on the other hand, are compatible, in particular totally or partially miscible and are in particular identical.

[0105] The total or partial compatibility of said compositions allowing their welding is defined by the ratio composed of:

[0106] - the difference in the glass transition temperatures of the two compositions present in the interfacial layer created by the weld,

[0107] - related to the difference in glass transition temperatures of the two com positions, before mixing by welding of these two compositions.

[0108] Compatibility is total when said ratio is equal to 0, and compatibility is partial when said ratio is different from 0 and less than 1, in absolute value. A total incompatibility of the polyamide included in the composition constituting the sealing layer with the polyamide included in the composition which impregnates the fibrous material of the intermediate layer is excluded. Similarly, a total incompatibility of the polyamide included in the composition which impregnates the fibrous material of the intermediate layer with the polyamide in the composition which impregnates the fibrous material of the external layer is excluded.

[0109] Advantageously, when the compatibility of said compositions is partial, said ratio is less than 30%, preferably less than 20%, in absolute value.

[0110] In embodiments, the glass transition temperature(s) of the blend, depending on whether the compatibility is total or partial, must be between the glass transition temperatures of said polyamides before blending and different from them, by at least 5°C, preferably by at least 10°C.

[0111] The expression “totally compatible” means that when, for example, two polyamides denoted PAa and PAb having a Tga and a Tgb respectively, are present respectively in two sealing layers or two adjacent reinforcing layers, and that Tga is lower than Tgb, then the mixture of the two polyamides has only one Tgab, the value of which is between Tga and a Tgb.

[0112] Advantageously, when the compatibility of said compositions is partial, said ratio is less than 30%, preferably less than 20%, in absolute value.

[0113] In embodiments, the glass transition temperature(s) of the blend, depending on whether the compatibility is total or partial, must be between the glass transition temperatures of said polyamides before blending and different from them, by at least 5°C, preferably by at least 10°C.

[0114] The expression “totally compatible” means that when, for example, two polyamides denoted PAa and PAb having respectively a Tga and a Tgb, are present respectively in two adjacent layers, and that Tga is lower than Tgb, then the mixture of the two polyamides has only one Tgab, the value of which is between Tga and a Tgb.

[0115] This Tgab value is then higher than Tga by at least 5°C, in particular by at least 10°C and lower than Tgb by at least 5°C, in particular by at least 10°C.

[0116] The expression “partially compatible” means that when, for example, two polyamides PAa and PAb having a Tga and a Tgb respectively, are present respectively in two adjacent sealing layers or two reinforcing layers, then the mixture of the two polyamides has two Tg: Tg'a and Tg'b, with Tga < Tg'a < Tg'b < Tgb.

[0117] These Tg'a and Tg'b values ​​are then higher than Tga by at least 5°C, in particular by at least 10°C and lower than Tgb by at least 5°C, in particular by at least 10°C.

[0118] An incompatibility of two polyamides results in the presence of two Tgs, Tga and Tgb, in the mixture of the two polyamides which correspond to the respective Tgs Tga and Tgb of the pure polymers taken separately.

[0119] It would not be outside the scope of the invention if the glass transition temperatures in the mixture of the two polyamides were identical or different from the temperatures before mixing, but if these two polyamides were reactive with each other.

[0120] According to other embodiments, the preform may comprise several layers of thermoplastic composite tapes, the thermoplastic polymer being able to be of the same or different nature as the thermoplastic polymer of the adjacent layer.

[0121] The preform may comprise up to 50 layers, in particular 47 layers. It may in particular comprise 10 layers of non-composite thermoplastic tapes, and 37 layers of thermoplastic composite tapes. In embodiments, the preform comprises 10 internal layers of non-composite thermoplastic tapes, forming a sealing layer after consolidation and from 10 to 50 layers of thermoplastic composite tapes, in particular 37 layers of thermoplastic composite tape, in particular impregnated at the core, forming a reinforcing layer.

[0122] In variants of the embodiments, the textile preform manufactured in step i) comprises a variation in section, in particular a narrowing of section, in particular sequential in the X direction.

[0123] In some embodiments, the cutting of the elongate element can be carried out at these sectional narrowings, and an insert can optionally be positioned there.

[0124] According to a characteristic of the invention, each module of the preform manufacturing device comprises independent supply means. Thus, each module can distribute ribbons of a different nature. The nature and dimensions of the ribbons can be different from one layer to another.

[0125] According to another characteristic of the invention, the main longitudinal guide comprises a substantially circular or polygonal section or even a free-form section. The elongated element obtained can thus have the shape of a tube or can be of a more complex shape depending on the use.

[0126] According to yet another characteristic of the invention, the supply means comprise at least one ribbon dispenser arranged around the supply ring. The implementation of the ribbon dispenser allows for easy storage and distribution of the ribbons towards the main guide, the dispenser(s) rotating around the guide according to the rotation speed of the supply ring.

[0127] According to one embodiment of the invention, the ribbon dispensers comprise pivoting means on the feed ring. The implementation of pivoting means makes it possible to orient the distribution of the ribbons towards the guide and thus to choose an angle between -90° and 90° between the ribbon and the guide. All the ribbons of the same module have substantially the same angle with the guide.

[0128] According to another embodiment of the invention, the ribbon dispensers comprise at least one guillotine capable of cutting at least one ribbon at the outlet of a dispenser and a motorized element capable of bringing the ribbon towards the guide.

[0129] According to another embodiment of the invention, the tape dispensers comprise welding means, for example ultrasonic welding means, capable of welding a ribbon to a present layer or upper layer. Other welding means compatible with the nature of the ribbons used are possible within the scope of the invention. When the diameter, or the section if it is not a tube with a circular section, of the elongated element varies, it is advantageous to add or remove one or more ribbons, which is possible within the scope of the invention thanks to the implementation of the guillotine and / or welding means.

[0130] According to one embodiment of the invention, the device further comprises a pulling assistance device capable of guiding the ribbons of the module(s).

[0131] The use of a pulling aid device makes it easier to slide the different layers of tape along the main guide. An example embodiment of a pulling aid device may be a system of at least one roller arranged downstream of the last module in the X direction. This or these rollers exert sufficient pressure to cause the layers of tape to slide on the main guide.

[0132] Depending on the nature of the ribbons, this assistance device can be removed during the manufacture of the textile element which, due to its rigidity, can advance alone on the guide. According to other embodiments, the nature of the ribbons does not require assistance with pulling.

[0133] According to an alternative embodiment of the invention, the device further comprises a secondary longitudinal guide of diameter or section greater than the diameter or section if it is not a tube with a circular section, of the main guide and capable of translating on the main guide. When the device is in operation, the implementation of a secondary guide of greater diameter or section makes it possible to increase the diameter, or the section if it is not a tube, of the elongated element, the ribbons being deposited on the secondary guide.

[0134] The feed speed V1 corresponds to the feed speed of the textile element on the main guide. The feed speed VI is therefore substantially the same for each of the modules. The feed speed VI and the rotation speed V2 of each module are linked, on the one hand, to the angle defined between the ribbon(s) fed by each of the modules and their feed speed.

[0135] According to one embodiment of the invention, the method further comprises a step of storing the elongated element wound around a storage reel. The method according to the invention makes it possible to manufacture, until the ribbon supply means are exhausted, an elongated element of large size, which may be, for example, up to a kilometer long. Storing the elongated element on a reel at the outlet of the device facilitates handling.

[0136] According to an alternative embodiment of the invention, the method further comprises the step of assisting in pulling the ribbons with the implementation of the pulling assistance device. The pulling assistance device is placed downstream of the last module delivering the last layer of the textile element. An operator can, for example, guide each of the layers of tape to the pull assist device which will then help slide the different layers onto the main guide.

[0137] According to one embodiment of the invention, the storage reel is a device for assisting in drawing the ribbons from the supply means of the modules of the manufacturing device.

[0138] According to one embodiment of the invention, the method further comprises the additional step of arranging a secondary longitudinal guide at the first module and translating said secondary guide along the X direction. The secondary guide makes it possible to enlarge the diameter or the section if it is not a tube, of the elongated element being manufactured or to reduce the diameter or the section of the element if a first secondary guide has already been implemented.

[0139] According to one embodiment of the invention, the method further comprises a step of bending the elongated element obtained at room temperature to a desired angle. An advantage of the manufacturing device is the possibility of bending the elongated element at room temperature.

[0140] By “room temperature” within the meaning of the present description, we mean a temperature between 15 and 25°C.

[0141] Step ii)

[0142] The elongated textile preform obtained in step i) is then consolidated by heating and cooling the thermoplastic composite ribbons.

[0143] More particularly, it is consolidated by melting and cooling the thermoplastic composite ribbons.

[0144] This heating and cooling step makes it possible to weld the different layers of ribbons constituting the preform together. The heating temperature is therefore determined according to the nature of the ribbons (10) chosen.

[0145] This step ii) is generally carried out under a pressure of between 1 bar and 25 bars, in particular between 5 bars and 10 bars, in particular between 6 bars and 8 bars.

[0146] Step ii) can be carried out in a mold, in particular external to the preform, in particular closed.

[0147] According to embodiments of step ii), the pressure is applied by means of a bladder internal to the preform.

[0148] According to further embodiments of step ii), an insert is positioned at the ends of the preform obtained in step i), preferably outside the ends of the preform. In other words, the internal surface of the insert may be in contact with the external surface of the preform.

[0149] The insert may in particular be metallic or made of a thermoplastic material, possibly composite.

[0150] Thus, in step ii), the insert can be advantageously co-consolidated to the ribbons of the preform during the consolidation step ii). When pressure is applied by means of an internal bladder to the preform, the ribbons of the preform are pressed against the internal wall of the insert, which in particular allows good consolidation of the preform and also improves the weld, and therefore the mechanical resistance, between the preform and the insert.

[0151] In these embodiments, when the winding angle of the ribbons around the axis of the tube or hollow body is greater than 65°, it is preferable to periodically cut the ribbons to facilitate their consolidation. Reservoir

[0152] According to another aspect, the invention relates to a tank, in particular for the storage of a fluid under pressure, in particular hydrogen, comprising at least one elongated textile and consolidated element, capable of being obtained according to the method as defined above.

[0153] Each consolidated elongated element is generally provided with an insert at its ends. It may include in particular

[0154] - at least one insert provided with an orifice, intended to allow the entry and exit of the fluid, and possibly

[0155] - an insert closing the elongated element and consolidated at one of its ends.

[0156] The consolidated elongated element may comprise, at each of its ends, an insert equipped with an orifice intended to allow the entry and exit of fluid. In this case, it is generally connected to other elongated elements via connectors.

[0157] According to embodiments, the tank comprises several elongated elements connected in series to each other by means of connectors.

[0158] In particular, the first consolidated elongated element of the series may be provided with an insert including an orifice allowing the entry of the fluid and the last elongated and consolidated element may be provided with an insert closing it, the intermediate consolidated elongated elements being equipped, at each of their ends, with inserts provided with an orifice allowing the circulation of the fluid between the first and the last elongated element of the series.

[0159] Advantageously, the reservoir is conformable and can be inserted into very restricted volumes, such as a battery pack, in particular for a motor vehicle. Preform

[0160] According to yet another aspect, the invention relates to an elongated, unconsolidated textile preform, capable of being obtained according to step i) of the method as defined above. Battery pack

[0161] According to yet another aspect, the invention relates to a battery pack, in particular for motor vehicle, comprising a storage tank for a fluid, in particular hydrogen, as defined above. Detailed description of the figures

[0162] A device according to the invention as illustrated in Figures 1 and 2 and designated as a whole by the reference 1 aims at the manufacture of an elongated textile and unconsolidated element. For these purposes, the device 1 comprises a frame 2 comprising a main longitudinal guide 3 in a direction X, and at least two modules 4 arranged in series around the guide 3 in the direction X.

[0163] The main longitudinal guide 3 is fixed on the frame 2. According to the illustrated embodiments, the main longitudinal guide 3 comprises a circular section and therefore has a tubular shape. This shape is not limiting for the invention, other shapes of guide 3 are compatible with the invention. The guide 3 is rectilinear and can comprise sections of different shapes such as square, rectangular, quadrilateral, triangular, polygonal, round, oval, or of mixed and / or free shape.

[0164] A module 4 of a device 1 according to the invention comprises, on the one hand, a feed ring 5 surrounding a section of the main longitudinal guide 3. According to the examples illustrated, the feed ring 5 has substantially the shape of a disc comprising a central hole in which the guide 3 is located.

[0165] A module 4 further comprises feed means 6 arranged on the crown 5. According to the illustrated embodiment, the feed means 6 are located on one face of the disc and feed at least one ribbon 10 towards the guide 3 with an angle relative to the direction X of between -90° and 90°.

[0166] A ribbon 10 compatible with the invention is, on the one hand, sufficiently flexible to be wound around the guide 3. [Fig. 3] illustrates an elongated element 11 obtained by means of the device 1 according to the invention. It is the successive layers of ribbon 10 arranged at different angles which allow the elongated element 11 obtained to keep its shape. [Fig. 4] illustrates a section of this elongated element 11 where the successive layers are visible.

[0167] The feed means 6 arranged on the crown 5 feed at least one ribbon 10 towards the guide 3 with a chosen angle of between -90° and 90° relative to the direction X. Each ribbon 10 is wound at least around the guide 3 or on the layer of ribbon 10 already present, i.e. the upper layer with a chosen overall feed speed VI.

[0168] Each module 4 also comprises means 15 for driving the crown 5. According to [Fig.2] and also visible in [Fig.5], the means 15 for driving are located on the face of the crown 5 opposite the supply means 6. The means 15 for driving the crown 5 make it possible to rotate the crown 5 around the guide 3 at a rotation speed V2. According to the illustrated embodiment, the drive means 15 comprise a motor comprising in particular a belt capable of rotating the crown 5 and a motor control unit in order to implement a rotation speed V2 of the crown 5. This configuration is not limiting for the invention.

[0169] The device illustrated in Figures 1 and 2 comprises two modules 4. The supply means 6 of the first module 4 comprise two dispensers 20 of ribbon 10 and the supply means 6 of the second module 4 comprise a single dispenser 20 of ribbon 10. The supply means 6 of the different modules 4 are in fact independent of each other. Thus each module 4 can deliver ribbons 10 of different nature and a chosen number of ribbons 10 per layer.

[0170] [Fig.6] illustrates a module 4 comprising six dispensers 20 of ribbon 10. The dispensers 20 of ribbon 10 are arranged around the supply ring 5. According to the illustrated embodiments, a dispenser 20 of ribbon 10 comprises a reel 21 fixed on one face of the ring 5 with pivoting means 22.

[0171] According to this illustrated but non-limiting embodiment, the pivoting means 22 comprise a fixed part 23 and a pivoting part 24 directed towards the coil 21. The coil 21 is free to pivot in the pivoting part 24 and the pivoting part is free to pivot relative to the fixed part 23. Thus, the coil 21 can be arranged according to a desired configuration and the pivoting means 22 can be locked according to the desired arrangement of the distributor 20.

[0172] [Fig.7] illustrates a particular embodiment of the invention in which a dispenser 20 of ribbon 10 also comprises a guillotine 25 capable of cutting the ribbon 10 at the outlet of the dispenser 20, a motor M capable of feeding the ribbon after cutting and ultrasonic welding means 26 capable of welding a ribbon 10 at the level of a layer of ribbons 10 present or upper layer. The illustration of the motor M, the guillotine 25 and the welding means 26 is schematic in [Fig.7] and other embodiments are possible and in particular with means of acting on a ribbon 10 outside the dispenser 20.

[0173] Figures 8 and 9 illustrate a particular embodiment of the invention. The device 1 comprises three modules 4. The first module 4 comprises four dispensers 20 of ribbon 10 which each deposit a ribbon 10 in the direction of advancement X, that is to say that the angle between the ribbon 10 and the guide 3 has a value of 0 degrees. The second module 4 comprises two dispensers 20 of ribbon 10 and finally the third module 4 comprises a single dispenser 20 of ribbon 10. This embodiment is not limiting for the invention.

[0174] In order to manufacture an elongated element 11 according to the invention, a first step consists of implementing supply means 6 on each of the modules 4 of the device 1. For this purpose, according to the examples illustrated, coils 21 comprising each a chosen ribbon 10 are arranged on each supply crown 5 of the device 1.

[0175] Preferably, the reels deliver the same ribbon 10 per module and each module 4 may comprise reels of ribbon 10 of different type.

[0176] According to the example illustrated in Figures 8 and 9, the ribbons 10 used have a width of between 20 and 10 mm and a thickness of approximately 150 microns.

[0177] A second step of the method consists in setting, on the one hand, the feed speed VI and, on the other hand, the rotation speed V2 of each of the modules 4. The precise and coordinated setting of these two values ​​makes it possible to define for each feed means 6 a desired angle between the ribbon 10 and the guide, this angle varies between -90 and 90° excluding these two interval limits. For example, and according to the example of the device illustrated in Figures 8 and 9, a first layer of ribbon 10 is deposited with an angle close to 0° relative to the direction X, a second layer of ribbon 10 is deposited with an angle of approximately 80° relative to the direction X and a third layer is deposited with an angle close to -80° relative to the direction X.

[0178] An example of parameterization consists of defining a feed speed VI substantially equal to one meter per minute and a rotation speed V2 of two modules 4 each distributing a ribbon 10 substantially equal to 360 revolutions per minute. This example is not limiting for the invention.

[0179] Modules 4 are then started.

[0180] Depending on the nature of the ribbons 10, a pulling aid device 30 is implemented in order to assist in pulling the ribbons 10 from the different layers of the element 11. According to the embodiment illustrated in FIGS. 8 and 9, the first layer of ribbon 10 from the first module 4 slides on the main guide 3 through the two other modules 4 implemented. The ribbons 10 of the first layer can slide alone if their nature allows it or with manual assistance. The ribbons 10 of the other layers are deposited on the previous layer and then pass through the pulling aid device 30. This aid device 30 is not always necessary for implementing the method but it can assist in sliding the different layers towards the X direction depending on the nature of the ribbons 10 used.

[0181] According to a particular embodiment with in particular ribbons of the first layer arranged at an angle close to 0° with the direction X, there is not necessarily a need for manual assistance to advance said ribbons 10.

[0182] According to another embodiment, once other layers of ribbons 10 are superimposed on the first layer, the elongated element 11 is manufactured without assistance and the pulling aid device 30 is no longer useful and can be removed. This may be a transitional period of start-up assistance which is necessary if the nature of the ribbon 10 used does not allow the ribbon to deploy efficiently from its reel 21.

[0183] The elongated element 11 which is manufactured can be stored wound around a storage reel, thus facilitating its subsequent handling. The elongated element 11 can also be cut as it is manufactured according to the desired size and according to the additional steps described below, for example increasing or reducing the dimensions.

[0184] According to one embodiment (not illustrated) the storage reel is a device

[0185] for assisting in pulling the ribbons 10. In fact, when it is wound, the textile element 11 causes the ribbons 10 which form it to be pulled.

[0186] When the elongated element 11 is of the desired size, it can then be cut. Another way of completing the process is to wait until the ribbons 10 are used up.

[0187] The obtained unconsolidated textile elongated element 11 can finally be recovered. Consolidation steps can then be applied to it, for example a thermoforming step when the dimensions allow it. When consolidating the elongated element 11, it is also possible to slightly vary the dimensions of the elongated element 11, in particular its perimeter, of the order of 10-20%.

[0188] According to a particular embodiment, a secondary longitudinal guide (not shown) is arranged at the level of the first module 4 during manufacture. This secondary guide of diameter or section greater than the diameter or section of the main guide 3 is placed upstream of the first module 4 and translates towards the manufacturing direction of the elongated element 11. The ribbons 10 of the different modules 4 are then deposited on the secondary guide, and again on the main guide 3 after the secondary guide has passed. It is thus also possible to significantly increase the diameter or section or even overall shape of the elongated element 11 during its manufacture. Such an elongated element 11 obtained is illustrated in [Fig. 10].

[0189] With an increase in diameter or cross-section, ribbons 10 similar to the ribbons 10 supplied by the corresponding module 4 can be added using ultrasonic welding means 26, thus making it possible to fill openings which could form due to the increase in the surface area of ​​the elongated element 11; such an example is illustrated in [Fig. 10] with ribbons 10 added to the layer below the upper layer when increasing the diameter of the element 11 and ribbons 10 cut when decreasing the diameter of the element 11.

[0190] According to another embodiment of the invention, the elongated element 11 obtained by the device 1 is bent at room temperature according to a desired angle such that the elongated element 11 appears in [Fig.l 1]. This step of bending at room temperature can be done by hand if the bending rigidity of the elongated element 11 obtained allows it.

[0191] According to another embodiment not illustrated, the elongated element 11 can also be consolidated by integrating a solid matrix at the level of one of the layers of ribbon 10 the component.

[0192] Of course, various other modifications may be made to the invention within the scope of the appended claims. Examples Example 1 (according to the invention):

[0193] The resin composing the matrix of the thermoplastic composite tape is 11 / BACT / 10T, the fiber used is Hyosung 2550 G10 carbon fiber, the fiber rate is 53% by volume.

[0194] The tensile stress at break at 0° (fiber direction) of the composite obtained with the composite tape is 2700 MPa. The width of the tape is Yi” and its thickness is 137 pm, on average.

[0195] Positioning in the preform, thermoplastic composite ribbons at + / - 55° from the axis of the tubular tank. The preform has a section restriction corresponding to half the initial diameter, allowing a metal insert to be positioned outside the preform, at its 2 ends.

[0196] It comprises 37 layers of thermoplastic composite tape,

[0197] The preform was manufactured continuously at a speed of Im / mn.

[0198] It is consolidated under a pressure of 6 bars at 300°C. The rise time in tem temperature, maintaining at 300°C and cooling are 20 minutes.

[0199] The tank is of type V, that is to say that it does not have an additional sealing layer, the composite reinforcement ensuring this function in addition to pressure resistance.

[0200] The total length of the tubular tank is 123 m, the inner diameter is 110 mm in the central part, 55 mm in the restriction and the transition between the central part and the restriction is conical at an angle of 45°. The thickness of the composite reinforcement is 5 mm. The burst pressure of the tank is 1605 bars.

[0201] The tubular tank obtained has a capacity of 10 liters and contains 2.98 kg of composite. Example 2 (according to the invention):

[0202] The resin composing the matrix of the thermoplastic composite tape is 11 / BACT / 10T, the fiber used is Hyosung 2550 G10 carbon fiber, the fiber rate is 53% by volume.

[0203] The tensile stress at break at 0° (fiber direction) of the composite obtained with the composite tape is 2700 MPa. The width of the tape is Yi” and its thickness is 137 pm, on average.

[0204] Positioning in the preform of the thermoplastic composite ribbons at + / -55° from the axis of the tubular tank. The preform has a cor section restriction corresponding to half of the initial diameter, allowing a metal insert to be positioned inside the preform.

[0205] It comprises 10 layers of thermoplastic tape with a width of Yi ' and a thickness of 200 qm in polyamide 11 and 37 layers of thermoplastic composite tape, having a width of Yi” and a thickness of 137 qm on average.

[0206] The preform was manufactured continuously at a speed of Im / min.

[0207] It is consolidated under a pressure of 6 bars at 300°C. The rise time in tem temperature, maintaining at 300°C and cooling are 20 minutes.

[0208] The resin composing the matrix of the thermoplastic composite tape is 11 / BACT / 10T, the fiber used is Hyosung 2550 carbon fiber, the fiber rate is 55% by volume. The width of the tape is YYY.

[0209] The length of the tubular tank is 1.33 m, the internal diameter is 110 mm in the central part of the composite reinforcement, 55 mm in the restriction and the transition between the central part and the restriction is conical at an angle of 45°. The thickness of the composite reinforcement is 5 mm and that of the polyamide 11 sealing layer, resulting from the consolidation of the thermoplastic tapes included in the preform, is 2 mm. The internal diameter of the tank in its central part is therefore 106 mm and 51 mm in the restriction.

[0210] The 2 layers are perfectly welded together and the tank is a single piece. This type of tank is type 4.5 (i.e. the sealing layer is of a different chemical nature from that of the composite matrix but the two resins are partially miscible, which allows perfect welding between them).

[0211] The burst pressure of the tank is 1620 bars.

[0212] The tubular tank obtained has a capacity of 10.15 liters and comprises 3.22 kg of composite and 0.89 kg of polyamide 11 liner Example 3 (according to the invention):

[0213] Connection by means of 25 mm diameter metal fittings, comprising a threaded fitting, of 6 tubular tanks as described in Example 2, to constitute a conformable H2 tank for an automobile with a capacity of 61 liters (approximately). This tank, consisting of the 6 tubular tanks, withstands the same pressure of 1620 bars as each of the 6 tubular tanks taken separately. The consolidation of the 6 preforms was carried out in parallel in 6 different closed molds, under a pressure of 6 bars at 300°C. The time for temperature rise, maintenance at 300°C and cooling was 20 minutes.

[0214] The total weight of composite used is 19.3 kg.

[0215] The total manufacturing time of the complete conformable tank is 39 min, depending on component as follows: • Preform manufacturing time of 6 x 1.21 = 7.26 min + cutting time, i.e. a total of 8 minutes to have the preforms ready to be consolidated • 3 minutes for positioning the 6 preforms in the molds with the inserts, • 20 minutes of molding time for the consolidation of the 6 preforms • 3 minutes demolding time for the 6 preforms • 5 minutes assembly time to connect the 6 tubular tanks together to others. Example 4 (comparative):

[0216] Production of a tank with an internal volume of 61 liters for an automobile, with an external diameter of 400 mm and a length of 0.88 m, (bases included) having a burst pressure of 1610 bars.

[0217] This tank is of type IV and has a composite reinforcement on the outside, weighing 36.7 kg and a polyethylene sealing layer, weighing 5 kg on the inside. There is no adhesion between the sealing layer and the composite reinforcement.

[0218] The composite reinforcement is composed of an epoxy matrix and Toray carbon fiber, ref T700 S, the fiber content is 70% by weight or 59% by volume (density of the carbon fiber used is 1.8 and that of the epoxy resin is 1.1). It is manufactured by wet filament winding: the dry fibers are unwound from a creel and are impregnated with resin by passing at a speed of 0.8 m / s, in a bath containing the liquid precursor of the epoxy resin, at room temperature. 4 strands are simultaneously wound around the liner. Each carbon strand has 1200 filaments (12K carbon strand), and has a linear mass of 0.83g / m. Given the fiber content of 70% by weight, each impregnated strand has a linear mass of 1.18 g / m. Thus, the entire winding at 0.8m / s, with 4 strands in parallel, lasts approximately 2.7 hours. This step is followed by polymerization of the resin in an oven at 60°C for 8 hours.

[0219] It is therefore noted that the manufacturing time of the type IV tank is much longer than that of the conformable type V tank of example 3, according to the invention and consumes much more composite and will therefore be significantly heavier and more expensive since the price of carbon fibers is a major factor in the cost of the tank. This shows that the effectiveness of the composite reinforcement in the type IV tank is at least 2 times lower than that of the composite making up the type V tank of example 3: in fact, to contain the same volume of hydrogen gas (61 1) while resisting the same internal pressure of 1600 bars, approximately 2 times more composite is required in the type IV tank made of epoxy carbon composite than in the conformable tank made of PPA carbon composite.

Claims

Claims

1. Method of manufacturing a tank, in particular for storing a fluid under pressure, comprising an elongated and consolidated textile element, said method comprising the steps of: (i) Manufacture of an elongated, unconsolidated textile preform, comprising several layers of thermoplastic composite tapes, each layer comprising a tape wound at a given angle, without embedding, by means of a device (1) comprising: - a frame (2) comprising a main longitudinal guide (3) in a direction X, said guide (3) being fixed on the frame (2) and - at least two modules (4) arranged in series around the guide (3) in the X direction, each module (4) comprising: - a feed ring (5) surrounding a section of the guide (3), - feed means (6) arranged on the ring (5) capable of feeding at least one ribbon (10) towards the guide (3) at a winding angle of between -90° and 90° with the direction X and at a feed speed VI, each ribbon (10) being capable of winding at least around the guide (3) or on the upper layer of ribbon (10), and - drive means (15) of the ring (5) capable of rotating the ring (5) around the guide (3) at a rotation speed V2, Said preform being manufactured according to a process comprising the steps of: - Implementation of the supply means (6) on each of the modules (4), said supply means (6) comprising selected ribbons (10), said selected ribbons (10) comprising at least thermoplastic composite ribbons - Setting the feed speed VI and the rotation speed V2 of each of the modules (4) and starting up each module (4), - Cutting of the elongated element (11) and / or exhaustion of the ribbons (10), and - Recovery of the unconsolidated elongated textile preform (11) obtained; (ii) Consolidation of the textile preform obtained in the previous step, by heating and cooling the thermoplastic composite tapes, whereby the preform is consolidated and an elongated and consolidated textile element is obtained.

2. A method according to claim 1, wherein the thermoplastic composite tapes comprise: - Continuous or discontinuous reinforcing fibers of an inorganic material; and - A thermoplastic polymer composition.

3. Method according to claim 2, in which the reinforcing fibers of an inorganic material are: - impregnated to the core or pre-impregnated with a composition of thermoplastic polymers, or - mixed with fibers of thermoplastic polymer(s).

4. Method according to any one of the preceding claims, in which the thermoplastic composite ribbon comprises continuous fibers impregnated with a composition based on a thermoplastic polymer, having a glass transition temperature (Tg), measured according to ISO 11357-3:2013, greater than 80°C, preferably greater than or equal to 100°C, even more preferably greater than 120°C, when the polymer is amorphous, and a melting temperature greater than 150°C when the polymer is semi-crystalline.

5. A method according to any one of claims 2 to 4, wherein the thermoplastic polymer composition of the composite tape comprises predominantly a polyamide, preferably semi-crystalline.

6. The method of claim 5, wherein the polyamide is an aliphatic, cycloaliphatic or semi-aromatic polyamide.

7. The method of claim 6, wherein the aliphatic polyamide is selected from PA 5, PA5-10, PA6, PA66, PA6-10, PA6-12, PA6-18, PA9, PA10-10, PA 10-12, PAU, PA12, and a mixture thereof.

8. The method of claim 7, wherein the semi-aromatic polyamide is selected from PA MPMDT / 6T, PA 11 / 6T, PA 11 / 10T, PA 11 / BACT, PA 5T / 10T, PA 11 / 6T / 10T, PA MXDT / 4T, PA MXDT / 6T, PA MXDT / 10T, PA MPMDT / 4T, PA MPMDT / 6T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA BACT / 4T, PA BACT / 10T / 6T, PA 11 / BACT / 4T, PA 11 / BACT / 6T, PA 11 / BACT / 10T, PA 11 / MXDT / 4T, PA 11 / MXDT / 6T, PA 11 / MXDT / 10T, PA 11 / MPMDT / 4T, PA 11 / MPMDT / 6T, PA 11 / MPMDT / 10T, PA 11 / MXDT / 10T, PA11 / 5T / 10T, and their mixture.

9. A method according to any preceding claim, wherein the fibers of the thermoplastic composite ribbons are selected from glass fibers, carbon fibers, basalt fibers or are basalt-based.

10. A method according to any preceding claim, wherein the fibers of the thermoplastic composite ribbons are unidirectional, i.e. all oriented along the length of the ribbon.

11. A method according to any preceding claim, wherein the composite ribbons contain a fiber content of between 40 and 70% by volume, preferably between 50 and 60% by volume of the thermoplastic composite ribbons.

12. A method according to any preceding claim, wherein the selected ribbons (10) further comprise non-composite ribbons (10) of thermoplastic polymer.

13. A method according to claim 12, wherein the non-composite thermoplastic polymer ribbons (10) represent a minor mass fraction of the preform relative to the mass fraction of the thermoplastic composite ribbons.

14. Method according to claim 13, in which the polymer composition constituting the non-composite thermoplastic ribbons (10) comprises predominantly a polyamide, preferably semi-crystalline.

15. Method according to claim 14, in which the thermoplastic polymer composition of the thermoplastic composite ribbons (10) on the one hand, and that of the non-composite thermoplastic polymer ribbons (10) on the other hand, are compatible, in particular identical.

16. Method according to any one of the preceding claims, in which the ribbons (10) have a thickness of between 50 and 300 pm, in particular between 50 and 260 pm and more particularly between 60 pm and 170 pm.

17. Method according to any one of the preceding claims, in which the ribbons (10) have a width of between 5 mm and 50 mm, in particular between 10 mm and 15 mm.

18. A method according to any preceding claim, wherein the winding angle of the ribbon (10) relative to the X direction is between +90° and -90°.

19. The method of claim 18, wherein the wrap angle is + / -54.8° to + / -10°, preferably + / -5°, more preferably + / -1°.

20. Method according to any one of the preceding claims, in which the textile preform manufactured in step i) comprises a variation in section, in particular sequential in the X direction.

21. Method according to any one of the preceding claims, in which step ii) is carried out in a mold, in particular external to the preform, in particular closed.

22. A method according to any preceding claim, wherein in step ii) the pressure is applied by means of a bladder internal to the preform.

23. A method according to any one of the preceding claims, wherein prior to step ii), an insert is positioned at the ends of the preform obtained in step i), preferably outside the ends of the preform.

24. A method according to claim 23, wherein the insert is made of an optionally composite thermoplastic material.

25. A method according to claims 23 and 24, wherein in step ii), the insert is co-consolidated to the ribbons (10) during the consolidation step

26. 11). Tank, in particular for storing a fluid under pressure, in particular hydrogen, comprising at least one elongated textile and consolidated element, capable of being obtained according to the method as defined in claims 1 to 25.

27. ​​A tank according to claim 26, wherein each consolidated elongate member is provided with an insert at its ends.

28. Tank according to claim 27, in which the insert is: - an insert closing the elongated and consolidated element, or - an insert provided with an orifice, intended to allow the entry and exit of the fluid.

29. Tank according to claims 26 to 28, comprising several consolidated elongated elements, in series, connected together via connectors.

30. Elongated, unconsolidated textile preform, obtainable according to step i) of the method according to claims 1 to 25.

31. Battery pack, in particular for a motor vehicle, comprising a hydrogen storage tank according to one of claims 26 to 29.

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