Method for manufacturing tank for storing pressurized fluid and tank obtained thereby

Abstract

The invention relates to a method for manufacturing a can, in particular a can for storing a pressurized fluid, comprising an elongated and consolidated textile element, said method comprising the following steps: i) manufacturing an elongated and unconsolidated textile preform comprising a plurality of layers of thermoplastic composite material tapes, each layer comprising at least one tape wound at a given angle, the preform is produced by means of a specific device (1). The invention relates to a method for producing a preform, comprising the following steps: implementing a feeding device (6) on each mold (4), said feeding device (6) comprising a selected tape (10), said selected tape (10) comprising at least a thermoplastic composite tape; setting the feed speed V1 and the rotation speed V2 of each module (4) and activating each module (4); cutting the elongated element (11) and / or depleting the strip (10); and recovering the resulting unconsolidated elongate fabric preform; the step i) does not comprise any step of weaving the belt; (ii) consolidating the fabric preform obtained in the previous step by heating and cooling a thermoplastic composite strip, whereby the preform is consolidated and a consolidated elongate fabric element is obtained.

Description

Technical Field

[0001] The present invention relates to a tank for storing a pressurized fluid, in particular hydrogen, and comprising an elongated fabric element, and a method for its manufacture. Background Art

[0002] The present invention relates to a tank for storing gas, in particular high pressure compressed gas, comprising a specific elongated fabric element, and a method for manufacturing the same.

[0003] One of the goals sought in the transport sector, and in particular in the vehicle sector, is to come up with vehicles that are increasingly less polluting. Electric or hybrid vehicles comprising batteries are therefore intended to gradually replace internal combustion engine vehicles, such as petrol or diesel vehicles. However, the battery proves to be a relatively complex component of the vehicle. Depending on where the battery is located in the vehicle, it may need to be protected from shocks and the external environment, which may be subject to extreme temperatures and varying humidity. Any risk of fire must also be prevented.

[0004] In addition, the battery of an electric or hybrid vehicle typically accounts for 10% to 30% of the vehicle's weight. This excess weight can lead to many disadvantages, including excessive consumption of fuel or energy.

[0005] Furthermore, it is important that the vehicle's operating temperature does not exceed 55°C to avoid damaging the battery and preserve its service life. Conversely, in winter, for example, it may be necessary to increase the battery's temperature to optimize its operation.

[0006] In addition, electric vehicles face several issues, namely battery range (autonomy), the use of rare earths in batteries (rare earth resources are not inexhaustible), and the production of electricity in different countries to charge the batteries.

[0007] Hydrogen is therefore an alternative to batteries as it can be converted into electricity via fuel cells to power electric vehicles.

[0008] However, hydrogen storage, especially in mobile storage, is technically difficult and expensive due to its very low molecular weight and very low liquefaction temperature. However, for efficient storage, small volumes should be stored, which requires that the hydrogen be kept at high pressure, taking into account the vehicle's operating temperature. This is particularly true for fuel cell hybrid road vehicles, which, in addition to battery-based electric power, strive for a range of about 600 to 700 kilometers, or less for mainly urban use.

[0009] Hydrogen tanks usually consist of a metal or polymer shell (also called liner), which should prevent hydrogen from diffusing outside the shell. The first shell should be protected by a second shell (usually made of composite materials), which is designed to withstand the internal pressure of the tank (e.g. 700 bar) and resist possible impacts or heat sources. In addition, the tank also includes a valve system, which should also be safe.

[0010] According to the French Hydrogen and Fuel Cell Association (AFHYPAC-Association Memorandum on Hydrogen (Revised December 2016, p. 4.2) on Hydrogen, For many years, the storage and distribution of hydrogen under pressure has become a standard practice, using steel cylinders or steel cylinder assemblies pressurized to 20 or 25 MPa (Type I and Type II), or metal with fiber material wrapped around the outside to consolidate. The disadvantage of this storage method is that it is large in volume, with a volume of only 14 kg / m at 20 MPa and normal temperature (21°C). 3 , and for methane it is 100kg / m 3 , and especially in terms of weight, due to the use of steel with low stress levels to avoid hydrogen-induced embrittlement problems. With the advent of the so-called Type IV composite tank technology, the situation has changed radically. The basic principle of the tank is to separate the two basic functions of tightness and mechanical resistance so that each can be managed independently. In a tank of this type, a bladder made of (thermosetting or thermoplastic) resin (called leakproof liner or jacket) is associated with a reinforcing structure (called reinforcing jacket or layer) consisting of fibers (glass, aramid, carbon) impregnated with thermosetting resin. Tanks of this type can operate at higher pressures while reducing the weight of the tank and preventing the risk of explosive rupture in the event of severe external aggression. Therefore, a pressure of 70 MPa (700 bar) has actually become the current standard.

[0011] In a Type IV tank, the barrier and reinforcement layers are made of different materials that do not adhere to each other, which often causes the barrier to collapse when gas accumulates at the interface between the barrier and reinforcement layers and the internal pressure of the tank decreases. In addition, drying of the Type IV tank is performed after the hydrostatic test, which takes a long time and is expensive because there is a risk of the barrier collapsing, and drying can only be performed under vacuum.

[0012] This problem has led to the development of V-tanks, based on the use of the same polymer for the barrier layer and for the matrix of the reinforcing layer, or at least a polymer that is compatible with the polymer constituting the composite matrix (so-called 4.5-tanks), in order to provide excellent and durable weldability between the two layers, thus obtaining a one-piece tank. Such tanks are still in the research and development phase.

[0013] For the production of composite shells, it is known how to use epoxy resins as a matrix for the composite material, in order to produce tanks that can have a high glass transition temperature (hereinafter referred to as Tg), i.e. a tank with a Tg greater than 100°C. A disadvantage of composite materials containing thermosetting resins, in particular epoxy resins, is that after the thermosetting resin has cured, and even after a certain number of pressure cycles / decompression cycles caused by inflation / emptying cycles, the composite material generally develops microcracks. This can lead to large variations in mechanical strength or even to a loss of mechanical strength. The performance is expected to decrease over time, so it is necessary to increase the carbon fiber content, which increases the weight and cost of the tank.

[0014] Furthermore, in the case of thermosetting resins, especially epoxy resins, microcracks adversely affect the impermeability of the composite reinforcement, which requires the use of thick barrier layers within the tank (ie Type IV tanks).

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

[0016] However, despite the improvements made to the Type IV tank, there are still drawbacks. In particular, there is a need to speed up the filling of the tank. Furthermore, in current solutions, the temperature resistance of the gas tank, in particular the hydrogen tank, is too low. Speeding up the filling of the tank would be an advantage, in particular saving costs for the consumer, in particular without having to additionally cool the hydrogen to -60°C before filling.

[0017] The use of a polyphthalamide reinforcement layer (hereinafter referred to as PPA) with a high glass transition temperature (hereinafter Tg) will have important advantages in terms of mechanical strength at high temperatures. In addition, the resin of the type is thermoplastic and will also be used to obtain a tank suitable for recycling. The thermoplastic properties of the resin will reduce the degree of microcracks in the composite shell, thereby enhancing its mechanical resistance and reducing the variability of mechanical resistance, which will significantly reduce the amount of carbon fiber used, thereby reducing the cost and carbon footprint of the V-type tank compared to the IV-type tank. In addition, the semi-crystalline nature of the resin will increase the sealing to gas (especially to hydrogen). Therefore, the composite shell will contribute to the impermeability of the tank, thereby reducing the thickness of the leakproof layer, and therefore reducing the cost and weight of the internal leakproof layer of the tank.

[0018] However, the manufacture of this type of tank by winding a thermal composite tape around a thermoplastic polymer barrier layer gives rise to difficulties related to the generation, at the end of tank manufacture, during the cooling of the tank, of significant residual stresses of thermal origin, inherent to the heterogeneous expansion of the materials involved, in particular between the fibers and the polymer constituting the barrier layer. This is particularly acute in the case of a PPA matrix constituting the carbon fiber composite reinforcement. In fact, the high temperatures when using composite tapes containing PPA are the main source of additional residual stresses in the tank, due to the high melting point of this type of resin and its high Tg. When the tank comprises a molded insert in a polyamide resin with a low Tg (typically a Tg of about 50°C), said residual stresses can cause deformations of the insert, thus preventing complete manufacture of the tank and in particular the tightening of the base closing the tank. When the container is a V-type (or 4.5-type, i.e., the polymer constituting the composite matrix and the polymer of the anti-leakage layer have different properties, but the two polymers remain compatible and can be welded to each other) tank, and the tank has a low Tg polyamide anti-leakage layer (more specifically, aliphatic polyamide), the residual stress may cause decohesion within the composite reinforcement layer, etc.

[0019] Furthermore, the methods for manufacturing such composite tanks are usually slow and expensive. Therefore, conventionally, the manufacture of single-piece composite tanks of 60 liters and above requires cycle times of several hours based on wet filament winding or hot winding of thermoplastic composite tapes. Furthermore, this method has proven to be inefficient when the tank size is below a certain level (usually below 30 liters). Finally, when it comes to wet impregnation or in-situ consolidation of thermoplastic composite tapes, the quality of the composite material obtained is not perfect due to the presence of porosity (which is related to the low pressure applied during pre-impregnation of the fibers with resin).

[0020] Therefore, the commonly used methods for manufacturing such composite tanks cannot easily and efficiently prepare conformable composite tanks (i.e., tanks that can be inserted into a complex and / or narrow shaped volume (e.g., the volume of a battery pack) in at least one of the three dimensions). One of the most promising types of conformable tanks is an assembly of small diameter composite tubes (typically <200 mm in diameter) interconnected by pipes. However, as mentioned above, current methods allow the tank to be manufactured in one piece, typically 60 liters, and therefore have a large overall size, at least impossible to insert into a battery pack, but the method is not suitable for the manufacture of small diameter tubular tanks.

[0021] Therefore, a simple, rapid and inexpensive process is now being sought that allows the production of tanks that are mechanically strong at high temperatures, recyclable, conformable and gastight. Such tanks will thus be used to store pressurized (especially high pressure) hydrogen and any type of gas.

[0022] Therefore, tanks with good mechanical resistance at high temperatures, recyclable, conformable, good gas tightness and suitable for manufacturing are currently sought. Such tanks will thus be used to store pressurized (especially high pressure) hydrogen and any type of gas. Summary of the invention

[0023] The method of the present invention solves such a problem, and the method comprises two steps:

[0024] - A first step i) manufactures an elongated and unconsolidated textile preform comprising a plurality of layers, preferably a plurality of layers, of at least one thermoplastic composite tape, each layer comprising tapes wound at a given angle and without warping; wherein said preform can be obtained by a specific device, such as Figure 1 shown.

[0025] - A second stage ii) consolidation of the textile preform obtained in the previous stage, in particular under pressure.

[0026] This approach has many advantages.

[0027] Firstly, unlike methods involving braiding or weaving and requiring passing through the same layer to stack multiple layers of woven or braided tapes, according to step i) of the method of the present invention, the manufacture of the preform can be carried out continuously, so that large-sized (especially small-diameter and long-length) fabric preforms can be obtained quickly and cheaply.

[0028] Furthermore, step i) of the method according to the invention enables a large number of layers to be superimposed, ie the preform may contain as many desired tape layers as modules are used.

[0029] The device implemented in step i) implements guides for arranging the strips in the same direction. This device thus makes it possible to produce elongated textile preforms of different shapes, whether cylindrical or not. The preform obtained according to step i) may also include limited portions of cross section where certain strips can be cut and welded and inserts are placed, in particular before consolidation. Similarly, the preform can easily be bent at room temperature to give it a specific non-linear shape, which can then be frozen during the consolidation of step ii). However, this will require a specific choice of the orientation of the fibers in the different layers of the preform. Thus, by this method, a conformable tank is easily obtained which can be inserted in particular into a volume similar to that of a battery pack of a vehicle.

[0030] Advantageously, step ii) makes it possible to co-consolidate the thermoplastic or metal insert with the strip of textile preform in a single step, in particular making it possible to close the tube to manufacture the tank, which is an additional economic advantage of the method for manufacturing a tank according to the invention. In addition, by co-consolidation, it is possible to improve the mechanical strength and / or the adhesion between the insert and the co-consolidated elongated textile element.

[0031] Thus, according to a first aspect, the invention relates to a method for manufacturing a tank, in particular a tank for storing a fluid under pressure, the tank comprising an elongated fabric and a consolidation element, the method comprising the following steps:

[0032] (i) producing an unconsolidated and elongated textile preform comprising a plurality of layers of thermoplastic composite tapes, each layer comprising at least one tape wound at a given angle, said preform being produced by means of an apparatus (1), said apparatus (1) comprising:

[0033] - a support (2) comprising a main longitudinal guide (3) in the X direction, said guide (3) being attached to the support (2); and

[0034] - at least two modules (4) arranged in series around the guide (3) along the direction X, each module (4) comprising:

[0035] - a feed crown (5) which surrounds a portion of the guide (3);

[0036] - a feeding device (6) arranged on the crown (5) and suitable for feeding at least one strip (10) to the guide (3) at a winding angle between -90° and 90° with respect to the direction X and at a feeding speed V1, each strip (10) being suitable for being wound at least around the guide (3) or around the upper layer of the strip (10); and a device (15) for driving the crown (5) and suitable for rotating the crown (5) around the guide (3) at a rotation speed V2.

[0037] The method for manufacturing the prefabricated component comprises the following steps:

[0038] - implementing on each module (4) a feeding device (6) comprising a selected tape (10) comprising at least a tape of thermoplastic composite material;

[0039] - parameterizing the feed speed V1 and the rotation speed V2 of each module (4) and starting each module (4),

[0040] - cutting the elongated element (11) and / or running out of the tape (10), and

[0041] - Recovering the unconsolidated elongated textile preform (11) obtained;

[0042] Step i) does not include any step of braiding the belt,

[0043] (ii) consolidating the textile preform obtained in the previous step by heating and cooling the thermoplastic composite material strip, whereby the preform is consolidated and an elongated and consolidated textile element is obtained.

[0044] In some embodiments, the method according to the present invention further comprises one or more of the following additional features:

[0045] -Thermoplastic composite tape comprising:

[0046] Continuous or discontinuous reinforcing fibers of inorganic material; and

[0047] Thermoplastic polymer compositions.

[0048] -Inorganic material reinforcement fibers are:

[0049] impregnating the core or pre-impregnating it with a thermoplastic polymer composition, or

[0050] Mixed with thermoplastic polymer fibers.

[0051] Thermoplastic composite tapes comprising continuous fibers impregnated with a composition containing a thermoplastic polymer and 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, more preferably greater than 120°C, when the polymer is amorphous, and a melting point greater than 150°C when the polymer is semi-crystalline.

[0052] The thermoplastic polymer composition of the composite tape mainly comprises polyamide, preferably semi-crystalline.

[0053] The polyamide is an aliphatic, cycloaliphatic or semiaromatic polyamide.

[0054] The aliphatic polyamide is selected from the group consisting of PA5, PA5-10, PA6, PA66, PA6-10, PA6-12, PA6-18, PA9, PA10-10, PA10-12, PA11, PA12 and mixtures thereof.

[0055] - Semi-aromatic polyamide is selected from AM MPMDT / 6T, PA 11 / 6T, PA 11 / 10T, PA 11 / BACT, PA 5T / 10T, PA 11 / 6T / 10T, PA MXDT / 4T, PA MXDT / 6T, PAMXDT / 10T, PA MPMDT / 4T, PA MPMDT / 6T, PAMPMDT / 10T, PABACT / 10T, PABACT / 6T, PABACT / 4T, PA BACT / 10T / 6T, PA 11 / BACT / 4T, PA11 / BACT / 6T, PA 11 / BACT / 10T, PA11 / MXDT / 4T, PA 11 / MXDT / 6T, PA 11 / MXDT / 10T, PA 11 / MPMDT / 4T, PA11 / MPMDT / 6T, PA11 / MPMDT / 10T, PA 11 / MXDT / 10T, PA11 / 5T / 10T and their mixtures.

[0056] The fibers of the thermoplastic composite tape are selected from glass fibers, carbon fibers, basalt fibers or basalt-containing fibers.

[0057] The fibers of the thermoplastic composite tape are unidirectional, ie all oriented along the length of the tape.

[0058] The composite tape comprises a fibre content of 40% to 70% by volume, preferably 50% to 60% by volume, of the thermoplastic composite tape.

[0059] The selected tapes (10) also include non-composite tapes (10) of thermoplastic polymers.

[0060] - The non-composite thermoplastic polymer tapes (10) account for a smaller mass fraction of the preform compared to the mass fraction of the thermoplastic composite tapes.

[0061] The polymer composition forming the non-composite thermoplastic tape (10) comprises mainly polyamide, preferably semi-crystalline polyamide.

[0062] The thermoplastic polymer composition of the thermoplastic composite tape (10) is compatible, in particular identical, to the thermoplastic polymer composition of the non-composite thermoplastic polymer tape (10).

[0063] The thickness of the tape ( 10 ) is between 50 and 300 μm, in particular between 50 and 260 μm, more particularly between 60 and 170 μm.

[0064] The width of the strip (10) is between 5 mm and 50 mm, in particular between 10 mm and 15 mm.

[0065] The winding angle of the tape (10) is between +90° and -90° relative to the direction X.

[0066] The winding angle is equal to + / -54.8° to + / -10°, preferably + / -5°, more preferably + / -1°.

[0067] The textile preform produced in step i) comprises a variation in cross section, in particular a successive variation along the direction X.

[0068] - Step ii) is carried out in a mould, in particular outside the preform, more particularly in a closed mould.

[0069] - Step ii) applying pressure via a bladder inside the preform.

[0070] - Prior to step ii), an insert is placed at the end of the preform obtained in step i), preferably outside the end of the preform.

[0071] - The insert is made of thermoplastic material, possibly a composite material.

[0072] - In step ii), the insert is co-consolidated with the strip (10) during the consolidation step ii).

[0073] According to a second aspect, the invention relates to a tank, in particular for storing a pressurized fluid, more particularly hydrogen, comprising at least one fabric and a consolidated elongated element obtainable by the method according to the invention.

[0074] In some embodiments, a tank according to the invention comprises one or more of the following additional features:

[0075] - Each consolidated elongated element is provided with an insert at its end.

[0076] -The inserts are:

[0077] - an insert enclosing an elongated and consolidated element, or

[0078] - Insert with orifices for letting fluid in and out.

[0079] - The tank comprises a plurality of consolidated elongated elements connected in series to each other by connectors.

[0080] The inventors have been able to demonstrate that the tank comprising elongated and consolidated textile elements obtained according to the method of the invention has a very good mechanical strength compared to prior art composite tanks.

[0081] In fact, compared to traditional methods involving the weaving of composite tapes, the method of the invention enables the tapes to be wound without buckling, which prevents local overstresses at the points where the fibers cross each other and therefore improves the mechanical strength of the elongated textile element obtained after consolidation.

[0082] Advantageously, the consolidation step ii) can be carried out under pressure, in particular at a pressure ranging from 5 bar to 10 bar, which makes it possible to further increase the mechanical strength of the composite material and reduce its porosity.

[0083] Conventional methods using wet filament winding or thermoplastic composite tape winding do not allow the application of high pressures, especially for a long period of time, so the quality of the consolidation is usually quite low.

[0084] Furthermore, the inventors have observed that step ii) of consolidating the preform under pressure gives the obtained elongated and consolidated textile element a very low residual porosity, in particular less than 5%, more particularly less than 2%, which enhances the barrier effect of the lining of a type IV or 4.5 tank, and even makes it possible to dispense with the lining and obtain a type V tank.

[0085] Furthermore, according to another advantage, when the thermoplastic polymer composition forming the composite tape is or comprises a semi-crystalline thermoplastic polymer, in particular a polyphthalamide, the crystallization of the resin during the cooling step may advantageously further improve the barrier effect of the tank against pressurized fluids.

[0086] Advantageously, the step of consolidating the preform in a closed mould can also reduce the thermal oxidation of the resin that occurs when the thermoplastic tape is placed in the open air, thus contributing to improving the mechanical properties of the composite tubular structure obtained.

[0087] According to a third aspect, the present invention relates to an unconsolidated and elongated textile preform obtainable in step i) of the method according to the invention.

[0088] 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.

[0089] According to a fifth aspect, the invention relates to a device according to the invention (in particular as Figures 1 to 11 for preparing a can according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] Figure 1 A perspective view showing an example of a device according to the invention is shown.

[0091] Figure 2 For Figure 1 The device is shown in a perspective view at relative angles.

[0092] Figure 3 A perspective view showing an example of an elongated element according to the invention.

[0093] Figure 4 for Figure 3 sectional view of .

[0094] Figure 5 is a perspective view of an example of a module according to the present invention.

[0095] Figure 6 for Figure 5 A three-dimensional diagram of the module.

[0096] Figure 7 is a perspective view of an example of a tape feeding device according to the present invention.

[0097] Figure 8 is a perspective view of another example of embodiment of the device according to the present invention.

[0098] Fig. 9 For Figure 8 The device is shown in a perspective view at relative angles.

[0099] Fig.10 is a perspective view of an elongated element comprising a variable cross-section according to the invention.

[0100] Fig.11 is a cross-sectional view of a curved elongated element according to the present invention.

[0101] It should be noted that in the figures, structural and / or functional elements common to different variants may have the same reference numerals. DETAILED DESCRIPTION

[0102] The invention is now described in more detail in a non-limiting manner in the following description.

[0103] Unless otherwise stated, all percentages referring to quantities are by volume.

[0104] Method of manufacturing a can

[0105] According to a first aspect, the invention relates to a method for manufacturing a tank, in particular a tank for storing a pressurized fluid, comprising an elongated and consolidated textile element, said method comprising the following steps:

[0106] (i) producing an elongated and unconsolidated fabric preform comprising a plurality of layers of thermoplastic composite tapes, each layer comprising at least one tape wound at a given angle, said preform being produced by means of an apparatus (1), said apparatus (1) comprising:

[0107] a support (2) comprising a main longitudinal guide (3) in the X direction, said guide (3) being attached to the support (2); and

[0108] At least two modules (4) arranged in series around the guide (3) along the direction X, each module (4) comprising:

[0109] a feed crown (5) which surrounds a portion of the guide (3);

[0110] a feeding device (6) arranged on the crown (5) suitable for feeding at least one strip (10) to the guide (3) at a winding angle between -90° and 90° relative to the direction X and at a feeding speed V1, each strip (10) being suitable for being wound at least on the guide (3) or on an upper layer of the strip (10); and

[0111] Means (15) for driving the crown (5), suitable for rotating the crown (5) around the guide (3) at a rotation speed V2, the method for manufacturing the preform comprising the following steps:

[0112] Implementing on each module (4) a feeding device (6), said feeding device (6) comprising a selected tape (10), said selected tape (10) comprising a tape of thermoplastic composite material;

[0113] configuring the feed speed V1 and the rotation speed V2 of each module (4) and starting each module (4),

[0114] cutting the elongated element (11) and / or running out the tape (10), and

[0115] recovering the unconsolidated elongated textile preform (11) obtained; step i) does not include any step of weaving the tape,

[0116] (ii) consolidating the textile preform obtained in the previous step by heating and cooling the thermoplastic composite material strip, whereby the preform is consolidated and an elongated and consolidated textile element is obtained.

[0117] Step i)

[0118] Step i) consists in producing an unconsolidated and elongated textile preform using so-called textile tapes, more specifically thermoplastic composite tapes. Figures 1 to 11 Step i) is performed using the specific apparatus described in .

[0119] As defined in the invention, the tape is referred to as a fabric and therefore comprises fibres, for example unidirectional carbon fibres, in this case dry fibres.A tape suitable for the invention is suitable for being wound around a guide and comprises a structure sufficiently rigid to remain wound around the guide.

[0120] Step i) of manufacturing the preform does not include any step of weaving the tape. It is thus used to manufacture an unconsolidated, warp-free elongated textile preform, ie with a warp (denoted by E) less than 0.5%, preferably equal to 0%.

[0121] The term "warp-free" as defined in the present invention means that the component bands of the fabric have no undulations.

[0122] The length of a fabric is usually less than the length of the yarns or tapes that make it up, because length is lost when the warp or tapes cross with the weft (or when different directions of yarn / webbing cross in a braid or fabric). The difference is the warp and is expressed as a percentage. Warp can be likened to the "undulation" of the local plane of the fabric perpendicular to the yarns or tapes within the fabric.

[0123] The warpage E increases with the density of intersections between different orientations of cloth, woven fabrics and more generally fabrics, including the out-of-plane undulations of their yarns or tapes. It is defined as a percentage as follows:

[0124] E=(L-L0) / L0×100

[0125] Wherein L is the length of the fabric, and L0 is the length of the straight yarn or webbing derived from the fabric of length L. The warp is less than 0.5%, preferably 0%, which is theoretically equivalent to a completely taut yarn, that is, equivalent to no undulation.

[0126] [Thermoplastic composite tape]

[0127] The term "thermoplastic composite tape" refers to a tape comprising fibers of an inorganic material and a thermoplastic polymer composition, suitable for melting and then solidifying under the action of a temperature, thereby consolidating a preform.

[0128] More specifically, the thermoplastic composite tape used in step i) may comprise:

[0129] - continuous or discontinuous reinforcing fibers of inorganic material; and

[0130] - Thermoplastic polymer composition.

[0131] In some embodiments, the thermoplastic composite tape comprises the following inorganic material fibers:

[0132] - its core is impregnated with a thermoplastic polymer composition (commonly called "tape");

[0133] - or a pre-impregnated thermoplastic polymer composition thereof, in particular in powder form, or

[0134] - It is mixed with thermoplastic polymer fibers, usually called "blended tapes".

[0135] In a preferred embodiment, the thermoplastic composite tape is a tape impregnated with a thermoplastic polymer composition at the core.

[0136] In some embodiments, the thermoplastic composite tape comprises continuous fibers impregnated with a composition containing a thermoplastic polymer and has 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, more preferably greater than 120°C, when the polymer is amorphous, and a melting point greater than 150°C when the polymer is semi-crystalline.

[0137] In some embodiments, the thermoplastic polymer composition of the composite tape comprises primarily polyamide, preferably a semi-crystalline polyamide.

[0138] In some embodiments, the polyamide is an aliphatic, cycloaliphatic, or semiaromatic polyamide.

[0139] The aliphatic polyamide may be selected from PA5, PA5-10, PA6, PA66, PA6-10, PA6-12, PA6-18, PA9, PA10-10, PA10-12, PA11, PA12 and mixtures thereof.

[0140] Semi-aromatic polyamide can be selected from PA MPMDT / 6T, PA11 / 10T, PA11 / BACT, PA5T / 10T, PA11 / 6T / 10T, PAMXDT / 4T, PA MXDT / 6T, PAMXDT / 10T, PAMPMDT / 4T, PAMPMDT / 6T, PA MPMDT / 10T, PABACT / 10T, PABACT / 6T, PABACT / 4T, PABACT / 10T / 6T, PA 11 / BACT / 4T, PA 11 / BACT / 6T, PA11 / BACT / 10T, PA 11 / MXDT / 4T, PA 11 / MXDT / 6T, PA 11 / MXDT / 10T, PA 11 / MPMDT / 4T, PA11 / MPMDT / 6T, PA11 / MPMDT / 10T, PA 11 / MXDT / 10T, PA11 / 5T / 10T and their mixtures.

[0141] The fibers of the composite tape may be selected from glass fibers, carbon fibers, basalt fibers or basalt-containing fibers.

[0142] The fibers of the thermoplastic composite tape are preferably unidirectional, which means that in this case the fiber orientation is all in the same direction, i.e. along the length of the tape. The tape may also consist of multiple layers of fibers, which are superimposed on each other and have different orientations from one layer to another, however, even in this case the fibers are non-woven and / or non-woven.

[0143] In some embodiments, the composite tape comprises a fiber content of between 40% and 70% (by volume), preferably between 50% and 60% (by volume) of the material forming the composite tape. The percentage of fibers can be determined according to known methods, such as the method described in ISO 14127:2008.

[0144] In some embodiments, the selected tape (10) further comprises a non-composite tape (10) of a thermoplastic polymer.

[0145] In other embodiments, the non-composite thermoplastic polymer tapes (10) comprise a smaller mass fraction of the preform than the mass fraction of the thermoplastic composite tapes.

[0146] In yet other embodiments, the polymer composition of the non-composite thermoplastic tape (10) comprises primarily polyamide, preferably semi-crystalline polyamide.

[0147] In a variant of embodiment, the thickness of the strip ( 10 ) is between 50 and 300 μm, in particular between 50 and 260 μm, more particularly between 60 and 170 μm.

[0148] In a variant of embodiment, the width of the strip ( 10 ) is between 5 mm and 50 mm, in particular between 10 mm and 15 mm.

[0149] The winding angle at which the tape is laid towards the guide is strictly greater than −90° relative to the feed direction X of the textile element and strictly less than 90° relative to the feed direction X of the textile element.

[0150] In other words, the winding angle of the tape (10) relative to the direction X is between +90° and -90°, excluding the critical values ​​of +90° and -90°.

[0151] In some embodiments, the winding angle is equal to + / - 54.8° to + / - 10°, preferably + / - 5°, more preferably + / - 1°.

[0152] According to one embodiment of the invention, the method further comprises a step of changing the diameter or cross section of the elongated element (if not a tube with a circular cross section). The device can also be used to enlarge or reduce the diameter or cross section of the elongated element (if not a tube with a circular cross section) in addition to implementing auxiliary guidance.

[0153] The textile preform obtained at the end of step I) generally comprises a plurality of layers, in particular as many layers as the modules (4) used. Each layer is formed by winding a tape, the properties of which may be the same or different from those of the tape of at least one adjacent layer.

[0154] Thus, the non-composite thermoplastic tape may in particular be inserted between two layers of thermoplastic composite tapes and / or form an inner layer of the preform and thus of the elongated textile element after consolidation. Said inner layer formed by the non-composite thermoplastic tape may in particular act as a barrier layer for the fluid contained in the tank.

[0155] In some embodiments, the thermoplastic polymer compositions of the thermoplastic composite tape (10) and the thermoplastic non-composite polymer tape (10) are compatible, more particularly fully or partially miscible, and most particularly identical.

[0156] The total or partial compatibility of the composition capable of being welded is defined by the ratio of:

[0157] - the difference in glass transition temperatures of the two compositions present in the interface layer produced by welding,

[0158] - divided by the difference in glass transition temperatures of the two compositions before mixing the two compositions by welding.

[0159] When the ratio is equal to 0, it is completely compatible; when the absolute value of the ratio is not 0 and is less than 1, it is partially compatible. The complete incompatibility of the polyamide contained in the composition forming the anti-leakage layer and the polyamide contained in the composition of the fiber material impregnated with the middle layer is excluded. Similarly, the complete incompatibility of the polyamide contained in the composition of the fiber material impregnated with the middle layer and the polyamide in the composition of the fiber material impregnated with the outer layer is excluded.

[0160] Advantageously, when the composition is partially compatible, the absolute value of the said ratio is less than 30%, preferably less than 20%.

[0161] In some embodiments, depending on whether the compatibility is complete or partial, the glass transition temperature or temperatures of the mixture should be between the glass transition temperatures of the polyamides prior to mixing and differ therefrom by at least 5°C, preferably at least 10°C.

[0162] The expression "complete compatibility" means that when, for example, two polyamides are represented as PAa and PAb, which have Tga and Tgb respectively, are respectively present in two adjacent anti-leakage layers or reinforcement layers, and Tga is less than Tgb, then the mixture of the two polyamides has only one Tgab, whose value is between Tga and Tgb.

[0163] Advantageously, when the composition is partially compatible, the absolute value of said ratio is less than 30%, preferably less than 20%.

[0164] In some embodiments, depending on whether the compatibility is complete or partial, the glass transition temperature or temperatures of the mixture should be between the glass transition temperatures of the polyamides prior to mixing and differ therefrom by at least 5°C, preferably at least 10°C.

[0165] The expression "complete compatibility" means that when, for example, two polyamides, denoted PAa and PAb, having Tga and Tgb, respectively, are present in two adjacent layers, and Tga is less than Tgb, the mixture of the two polyamides has only one Tgab, whose value is between Tga and Tgb.

[0166] The value of Tgab is then at least 5° C. greater than Tga (more particularly at least 10° C. greater) and at least 5° C. less than Tgb (more particularly at least 10° C. less).

[0167] The expression "partial compatibility" means that when, for example, two polyamides PAa and PAb, respectively having Tga and Tgb, are present in two adjacent anti-leakage layers or two reinforcing layers, the mixture of the two polyamides has two Tg's: Tg'a and Tg'b, where Tga <Tg'a<Tg'b<Tgb。

[0168] Said values ​​Tg'a and Tg'b are then at least 5° C. greater (more particularly at least 10° C. greater) than Tga and at least 5° C. less (more particularly at least 10° C. less) than Tgb.

[0169] The incompatibility of the two polyamides results in the presence of two Tg's (Tga and Tgb) in the mixture of the two polyamides, which correspond to the Tg's (Tga and Tgb) of the pure polymers obtained individually.

[0170] It also does not go beyond the scope of the invention if the glass transition temperatures in the mixture of the two polyamides are identical or different at the temperature before mixing, but if the two polyamides react with one another.

[0171] According to other embodiments, the preform may include multiple layers of thermoplastic composite tape, the thermoplastic polymer may have the same or different properties compared to the thermoplastic polymer of adjacent layers.

[0172] The preform may include up to 50 layers, in particular 47 layers. In particular, it may include 10 layers of non-composite thermoplastic tapes and 37 layers of thermoplastic composite tapes. In some embodiments, the preform comprises: 10 inner layers of non-composite thermoplastic tapes, forming a leakproof layer after consolidation; and 10 to 50 layers of thermoplastic composite tapes (in particular 37 layers of thermoplastic composite tapes, more particularly impregnated in the core), forming a reinforcement layer.

[0173] In a variant of embodiment, the textile preform produced in step i) comprises a variation in cross section, in particular a narrowing of the cross section, more particularly a sequential variation along direction X.

[0174] In some embodiments, the elongated member may be cut where the cross-section narrows and an insert may be placed therein if appropriate.

[0175] According to one characteristic of the invention, each module of the device for manufacturing preforms comprises an independent feeding device. Thus, each module can be allocated tapes of different properties. The properties and dimensions of the tapes may differ from one layer to another.

[0176] According to another characteristic of the invention, the main longitudinal guide comprises a substantially circular or polygonal cross section or a free-form cross section.The elongated element thus obtained may have the shape of a tube or may have a more complex shape depending on the use.

[0177] According to another characteristic of the invention, the feeding device comprises at least one tape dispenser arranged around the feeding crown. The realization of the tape dispenser allows easy storage and distribution of the tapes to the main guide, the dispenser rotating around the guide according to the rotation speed of the feeding crown.

[0178] According to one embodiment of the invention, the tape dispenser comprises a pivoting device on the feed crown. The pivoting device is used to direct the tape dispense towards the guide, thereby selecting an angle between -90° and 90° between the tape and the guide. All tapes of the same module have substantially the same angle with the guide.

[0179] According to another embodiment of the invention, the tape dispenser comprises at least one knife adapted to cut at least one tape exiting the dispenser and a motorized element adapted to bring the tape towards a guide.

[0180] According to another embodiment of the invention, the tape dispenser comprises welding means, for example ultrasonic welding means, suitable for welding the tape to the current layer or to the upper layer. Within the framework of the invention, it is possible to use other welding means compatible with the nature of the tape used. When the diameter or cross section of the elongated element varies (if no tube with a circular cross section is involved), it is advantageous to add or remove one or more tapes, which is possible within the framework of the invention due to the use of a guillotine and / or a welding means.

[0181] According to one embodiment of the invention, the device further comprises a traction assist device adapted to guide the belt of the one or more modules.

[0182] The use of a traction aid facilitates the sliding of the different layers of tape along the main guide. An example of an embodiment of a traction aid may be a system of at least one roller, which is arranged downstream of the last module along the direction X. The one or more rollers apply sufficient pressure to slide the layers of tape on the main guide.

[0183] According to the nature of the belt, the auxiliary means may be removed during the manufacture of the textile element which, due to its rigidity, may be advanced on the guide alone.According to other embodiments, the nature of the belt does not require any traction assistance.

[0184] According to a variant of the embodiment of the invention, the device also comprises an auxiliary longitudinal guide having a diameter or cross section greater than that of the main guide (if no tube of circular cross section is involved) and adapted to translate on the main guide. When the device is operated, the diameter or cross section of the elongated element (if no tube of circular cross section is involved) is increased using the auxiliary guide of greater diameter or cross section, on which the belt is arranged.

[0185] The feed speed V1 corresponds to the feed speed of the fabric element on the main guide. Therefore, the feed speed V1 of each module is substantially the same. On the one hand, the feed speed V1 and the rotation speed V2 of each module are related to the angle defined between the one or more strips fed by each module and the feed speed.

[0186] According to one embodiment of the invention, the method further comprises the step of storing the elongated element wound on a storage reel. The method according to the invention makes it possible to manufacture elongated elements of considerable size, for example up to one kilometer, until the tape feed device is exhausted. Storing the elongated elements in reels at the outlet of the device facilitates handling.

[0187] According to a variant of the embodiment of the invention, the method further comprises a step of assisting the traction of the belt using a traction auxiliary device. The traction auxiliary device is arranged downstream of the last module conveying the last layer of textile elements. For example, the operator can guide each layer of belt onto the traction auxiliary device, which will then help slide the different layers onto the main guide.

[0188] According to one embodiment of the invention, the storage reel is a pulling aid for withdrawing the tape from a feed device of a module of a manufacturing device.

[0189] According to one embodiment of the invention, the method further comprises the additional step of arranging auxiliary longitudinal guides at the first mould and translating said auxiliary guides along the direction X. The auxiliary guides can enlarge the diameter or the cross section of the elongated element being manufactured (if no tube is involved) or reduce the diameter or the cross section of the element if the first auxiliary guides have been used.

[0190] According to one embodiment of the invention, the method further comprises the step of bending the elongated element obtained at ambient temperature into a desired angle. An advantage of this manufacturing device is that the elongated element can be bent at room temperature.

[0191] The "ambient temperature" defined in this specification refers to a temperature between 15°C and 25°C.

[0192] Step ii)

[0193] The elongated textile preform obtained in step i) is then consolidated by heating and cooling the thermoplastic composite material strip.

[0194] More specifically, the thermoplastic composite tape is consolidated by melting and cooling it.

[0195] The heating and cooling steps serve to weld together the strips forming the different layers of the preform. The heating temperature is therefore determined according to the properties of the strip (10) chosen.

[0196] Step ii) is generally carried out at a pressure of 1 bar to 25 bar, in particular 5 bar to 10 bar, more in particular 6 bar to 8 bar.

[0197] Step ii) may be carried out in a mould, in particular outside the preform, more particularly in a closed mould.

[0198] According to an embodiment of step ii), the pressure is applied by means of a bladder inside the preform.

[0199] According to yet another embodiment of step ii), the insert is placed at the end of the preform obtained in step i), preferably outside the end of the preform. In other words, the inner surface of the insert may be in contact with the outer surface of the preform.

[0200] In particular, the insert can be metallic or made of a thermoplastic material, if appropriate a composite material.

[0201] Thus, during step ii), advantageously, the insert can be co-consolidated with the strip of the preform during the consolidation step ii). When pressure is applied by the bladder inside the preform, the strip of the preform is pressed against the inner wall of the insert, which in particular enables good consolidation of the preform and also improves welding and therefore improves the mechanical resistance between the preform and the insert.

[0202] In such embodiments, when the wrapping angle of the tape around the axis of the tube or hollow body is greater than 65°, the tape is preferably cut periodically to facilitate its consolidation.

[0203] Can

[0204] According to another aspect, the invention relates to a tank, in particular for storing a pressurized fluid, more particularly hydrogen, comprising at least one fabric and a consolidated elongated element, obtainable according to the method as defined above.

[0205] Typically, each end of the consolidated elongated element is provided with an insert. Specifically, it may include:

[0206] - at least one insert provided with an orifice for the ingress and egress of fluid; and, if appropriate

[0207] - An insert closing and consolidating the elongated element at one of its ends.

[0208] The consolidated elongated element may comprise an insert at each end thereof, the insert being provided with an orifice for letting fluid in and out. In this case, the consolidated elongated element is usually connected to the other elongated element by a connector.

[0209] In some embodiments, the tank comprises a plurality of elongated elements connected in series to each other by connectors.

[0210] More specifically, the first consolidated elongated element in series may be provided with an insert comprising an orifice for allowing fluid to enter; and the last consolidated elongated element may be provided with an insert closing it; each end of the intermediate consolidated elongated elements is provided with an insert provided with an orifice allowing fluid to circulate between the first and last elongated elements in series.

[0211] Advantageously, the can is conformable and can be inserted into very small volumes, such as a battery pack, particularly a battery pack for a motor vehicle.

[0212] Prefab

[0213] According to a further aspect, the present invention relates to an unconsolidated and elongated textile preform obtainable according to step i) of the method as defined above.

[0214] Battery Pack

[0215] According to a further aspect, the invention relates to a battery pack, in particular for a motor vehicle, comprising a tank as defined above for storing a fluid, more particularly hydrogen.

[0216] Detailed description with drawings

[0217] like Figure 1 and Figure 2The device according to the invention shown is indicated as a whole by the reference numeral 1 and is intended for manufacturing unconsolidated and elongated textile elements. To this end, the device 1 comprises a support 2 comprising a main longitudinal guide 3 in the X direction and at least two modules 4 arranged in series around the guide 3 in the X direction.

[0218] The main longitudinal guide 3 is fixed to the support 2. According to the embodiment shown, the main longitudinal guide 3 comprises a circular cross section and is therefore tubular. The invention is not limited to this form, and other forms of guides 3 are also compatible with the invention. The guide 3 is rectilinear and can comprise cross sections of different shapes, such as square, rectangular, quadrilateral, triangular, polygonal, circular, elliptical or mixed shapes and / or free shapes.

[0219] One side of the module 4 of the device 1 according to the invention comprises a feeding crown 5 surrounding a portion of the main longitudinal guide 3. According to the embodiment shown, the feeding crown 5 has substantially the form of a disc comprising a central hole in which the guide 3 is located.

[0220] The other side of module 4 comprises feeding means 6 arranged on crown 5. According to the embodiment shown, feeding means 6 are situated on one face of the disc and feed at least one strip 10 to guide 3 at an angle between -90° and 90° relative to direction X.

[0221] On the one hand, the belt 10 compatible with the present invention is flexible enough to be wrapped around the guide 3 . Figure 3 An elongated element 11 obtained by means of the device 1 of the invention is shown. Successive layers of strips 10 arranged at different angles allow the elongated element 11 obtained to retain its shape. Figure 4 A cross section of the elongated element 11 is shown, wherein the successive layers are visible.

[0222] Feeding means 6 arranged on the crown 5 feed at least one strip 10 towards the guide 3 at a chosen angle between -90° and 90° relative to the direction X. Each strip 10 is wound at least around the guide 3 or onto an already formed layer of strip 10, ie the upper layer, at a chosen overall feeding speed V1.

[0223] Each module 4 further comprises a drive device 15 for the crown 5. Figure 2 And in Figure 5 As can also be seen in FIG. 1 , drive means 15 are located on the face of crown 5 opposite to feed means 6. Drive means 15 of crown 5 are intended to rotate crown 5 around guide 3 at a rotation speed V2. According to the embodiment shown, drive means 15 comprise a motor and a control unit of the motor, so as to achieve the rotation speed V2 of crown 5, wherein the motor notably comprises a belt suitable for rotating crown 5. The invention is not limited to this configuration.

[0224] Figure 1 and Figure 2 The device shown comprises two modules 4. The feed device 6 of the first module 4 comprises two dispensers 20 for strips 10, while the feed device 6 of the second module 4 comprises only one dispenser 20 for strips 10. The feed devices 6 of the different modules 4 are in fact independent of one another. Thus, each module 4 can deliver strips 10 of different properties and a selected number of strips 10 per layer.

[0225] Figure 6 A module 4 is shown comprising six dispensers 20 of tapes 10. The dispensers 20 of tapes 10 are arranged around the feeding crown 5. According to the embodiment shown, the dispensers 20 for tapes 10 comprise a reel 21 fastened to one face of the crown 5 by pivoting means 22.

[0226] According to the illustrated embodiment, but not limited to the illustrated embodiment, the pivot device 22 includes a fixed portion 23 and a pivot portion 24 facing the reel 21. The reel 21 is free to pivot in the pivot portion 24, and the pivot portion is free to pivot relative to the fixed portion 23. Thereby, the reel 21 can be arranged in a desired configuration, and the pivot device 22 can be locked in the desired arrangement of the dispenser 20.

[0227] Figure 7 A particular embodiment of the invention is shown in which the dispenser 20 of the tape 10 further comprises: a knife 25 adapted to cut the tape 10 at the outlet of the dispenser 20; a motor M adapted to feed the tape after cutting; and an ultrasonic welding device 26 adapted to weld the tape 10 to the current layer or to the upper layer of the tape 10. Figure 7 The motor M, the knife 25 and the welding device 26 are schematically shown in FIG. 2 , and other embodiments are possible, in particular with devices acting on the belt 10 outside the dispenser 20 .

[0228] Figure 8 and Fig. 9 A particular embodiment of the invention is shown. The device 1 comprises three modules 4. The first module 4 comprises four dispensers 20 for the tape 10, each dispenser 20 placing the tape 10 along the advancing direction X, i.e. the angle between the tape 10 and the guide 3 is 0 degrees. The second module 4 comprises two dispensers 20 for the tape 10 and finally the third module 4 comprises only one dispenser 20 for the tape 10. The invention is not limited to such an embodiment.

[0229] To manufacture the elongated element 11 according to the invention, the first step consists in implementing the feeding device 6 on each module 4 of the device 1. To this end, each reel 21 comprising a selected tape 10 is provided on each feeding crown 5 of the device 1 according to the example shown.

[0230] Preferably, the reel delivers the same tape 10 for each module, and each module 4 may comprise a different type of tape reel 10 .

[0231] according to Figure 8 and Fig. 9 In the example shown, the tape 10 used has a width between 20 mm and 10 mm and a thickness of approximately 150 microns.

[0232] The second step of the method consists in parameterizing, on the one hand, the feed speed V1 of each module 4 and, on the other hand, the rotation speed V2 of each module 4. A precise and coordinated configuration of these two values ​​makes it possible to define, for each feed device 6, a desired angle between the belt 10 and the guide, which angle varies between -90° and 90° (excluding the two interval end values). For example, according to Figure 8 and Fig. 9 In the example of the device shown, the first layer of tape 10 is placed at an angle of about 0° relative to the direction X, the second layer of tape 10 is placed at an angle of about 80° relative to the direction X, and the third layer is placed at an angle of about -80° relative to the X direction.

[0233] An example of a configuration is to define a feed speed V1 substantially equal to one meter per minute and a rotation speed V2 of the two modules 4 (each distributing a strip 10 ) substantially equal to 360 revolutions per minute. The invention is not limited to this example.

[0234] Module 4 is then started.

[0235] Depending on the nature of the tape 10, a pulling aid 30 is employed to assist in pulling the tape 10 from the different layers of the element 11. Figure 8 and Fig. 9 In the embodiment shown, the first layer of tape 10 from the first module 4 is slid on the main guide 3 through the other two modules 4 used. The first layer of tape 10 can be slid alone, if its nature allows, or with manual assistance. The tapes 10 of the other layers are placed on the previous layer and then passed through the traction assistance device 30. The assistance device 30 is not always necessary for the implementation of the method, but can assist the sliding of the different layers in the direction X according to the nature of the tapes 10 used.

[0236] According to a particular embodiment, in particular the tape of the first layer is arranged at an angle of about 0° relative to the direction X, manual assistance is not necessarily required to advance said tape 10 .

[0237] According to another embodiment, once the other layers of tape 10 are superimposed on the first layer, the elongated element 11 is manufactured without assistance and the pulling aid 30 is no longer useful and can be removed. This can be a transitional start-up aid phase, which is necessary if the nature of the tape 10 used does not allow the tape to be effectively unwound from its reel 21.

[0238] The manufactured elongated element 11 can be stored by winding it on a storage reel, thereby facilitating subsequent processing. The elongated element 11 can also be cut during manufacture according to the desired size and according to the additional steps described below (eg by increasing or decreasing the size).

[0239] According to one embodiment (not shown), the storage reel is a pulling aid for the strip 10. In fact, during the winding of the textile element 11, the textile element 11 pulls the strip 10 forming it.

[0240] When the elongated element 11 has the desired dimensions, it can be cut.Another way of completing the method is to wait for the tape 10 to run out.

[0241] The obtained textile and unconsolidated elongated element 11 can finally be recycled. It can then be subjected to a consolidation step and, when the dimensions allow, a thermoforming step. During the consolidation of the elongated element 11, it is also possible to slightly modify the dimensions of the elongated element 11, in particular its circumference, by about 10-20%.

[0242] According to a particular embodiment, during manufacture, an auxiliary longitudinal guide (not shown) is provided at the first module 4. The auxiliary guide has a diameter or a cross section greater than that of the main guide 3, is placed upstream of the first module 4 and is translated in the direction of manufacture of the elongated element 11. The strip 10 of the different modules 4 is then placed on the auxiliary guide and, after passing through the auxiliary guide, is placed again on the main guide 3. Thus, the diameter or the cross section or the overall shape of the elongated element 11 can also be greatly increased during its manufacture. Fig.10 Such an elongated element 11 is shown in FIG.

[0243] As the diameter or cross section increases, strips 10 similar to those supplied by the corresponding module 4 can be added by means of ultrasonic welding devices 26 , making it possible to fill the openings which may be formed by the increase in the surface of the elongated element 11 . Fig.10 An example is shown in FIG. 1 , in which the tape 10 is added to a layer below an upper layer when the diameter of the element 11 increases, and the tape 10 is cut when the diameter of the element 11 decreases.

[0244] According to another embodiment of the invention, the elongated element 11 obtained by the device 1 is bent at ambient temperature according to a desired angle, such as Fig.11 The bending step can be done by hand at ambient temperature if the bending stiffness of the elongated element 11 obtained allows it.

[0245] According to another embodiment not shown, the elongated element 11 can also be consolidated by bonding a solid matrix at a layer of the strip 10 constituting the elongated element 11 .

[0246] Of course, various other modifications can be made to the invention within the framework of the attached claims.

[0247] Example

[0248] Example 1 (according to the present invention):

[0249] The resin constituting the matrix of the thermoplastic composite tape is 11 / BACT / 10T, and the fiber used is Hyosung 2550G10 carbon fiber, with a fiber content of 53% (by volume).

[0250] The composite material obtained with the composite tape had a tensile stress at break of 2700 MPa at 0° (fiber direction). The average width of the tape was 17 inches and the average thickness was 137 μm.

[0251] The position of the thermoplastic composite tape in the preform is + / - 55° from the axis of the tubular tank. The cross-sectional restriction of the preform corresponds to half of the initial diameter, allowing the metal inserts to be located outside the two ends of the preform.

[0252] The preform comprises 37 layers of thermoplastic composite tape.

[0253] The preforms were produced continuously at a speed of 1 m / min.

[0254] It was consolidated at 300°C and 6 bar pressure. The time for heating, holding at 300°C and cooling was 20 minutes.

[0255] The tank is a V-tank, ie it has no additional leakproof layer, the composite reinforcement ensuring the leakproof function in addition to bearing the pressure.

[0256] The total length of the tubular tank is 123m, the inner diameter of the central part is 110mm, the inner diameter of the restricted part is 55mm, and the transition between the central part and the restricted part is conical at an angle of 45°. The thickness of the composite reinforcement is 5mm. The stacking of the structure does not contain any weaving, and the warpage E is less than 0.5%. The burst pressure of the tank is 1605bar.

[0257] The tubular can obtained had a capacity of 10 liters and contained 2.98 kg of composite material.

[0258] Example 2 (according to the present invention):

[0259] The resin constituting the matrix of the thermoplastic composite tape is 11 / BACT / 10T, and the fiber used is Hyosung 2550G10 carbon fiber, with a fiber content of 53% (by volume).

[0260] The composite material obtained with the composite tape had a tensile stress at break of 2700 MPa at 0° (fiber direction). The average width of the tape was 17 inches and the average thickness was 137 μm.

[0261] The position of the thermoplastic composite tape in the preform is + / - 55° from the axis of the tubular tank. The cross-sectional restriction of the preform corresponds to half of the initial diameter, allowing the metal insert to be inserted into the preform.

[0262] The preform included 10 layers of thermoplastic tapes made of polyamide 11 with a width of 17 inches and a thickness of 200 μm, and 37 layers of thermoplastic composite tapes with an average width of 17 inches and a thickness of 137 μm.

[0263] The preforms were produced continuously at a speed of 1 m / min.

[0264] It was consolidated at 300°C and 6 bar pressure. The time for heating, holding at 300°C and cooling was 20 minutes.

[0265] The resin constituting the matrix of the thermoplastic composite tape is 11 / BACT / 10T, and the fiber used is Hyosung 2550 carbon fiber with a fiber content of 55% (by volume). The width of the tape is 17 inches. The stacking of the through structure does not contain any weaving, and the warpage E is less than 0.5%.

[0266] The length of the tubular tank is 1.33 m, the inner diameter of the central part of the composite reinforcement is 110 mm, the inner diameter of the restricted part is 55 mm, and the transition between the central part and the restricted part is conical at an angle of 45°. The thickness of the composite reinforcement is 5 mm, and the thickness of the polyamide 11 leakproof layer (consolidated by the thermoplastic tape included in the preform) is 2 mm. Therefore, the inner diameter of the central part of the tank is 106 mm, and the inner diameter of the restricted part is 51 mm.

[0267] The two layers are perfectly welded together and the tank is one piece. This type of tank is type 4.5 (the leakproof layer is chemically different from the composite base layer, but the two resins are partially miscible, which allows a perfect weld between them).

[0268] The bursting pressure of the tank is 1620 bar.

[0269] The obtained tubular tank had a capacity of 10.15 liters and comprised 3.22 kg of composite material and 0.89 kg of polyamide 11 lining.

[0270] Example 3 (according to the present invention):

[0271] As described in Example 2, six tubular tanks were connected by metal fittings (including threaded connections) with a diameter of 25 mm to form a conformable H2 tank for vehicles with a capacity of 61 liters (approximately). The tank consists of six tubular tanks and is subjected to the same pressure as the six tubular tanks alone, which is 1620 bar. The consolidation of the six preforms was carried out in parallel in six different closed molds at 300° C. and 6 bar pressure. The heating, 300° C. holding and cooling times were all 20 minutes.

[0272] The total weight of the composite material used was 19.3 kg.

[0273] The total build time for the complete conformable tank was 39 minutes, broken down as follows:

[0274] The prefabricated part manufacturing time is 6 × 1.21 = 7.26 minutes + cutting time, i.e. the total time required to place the prefabricated part for consolidation is 8 minutes

[0275] · Place 6 preforms in a mold with inserts within 3 minutes

[0276] Consolidation time for 6 preforms is 20 minutes

[0277] Demolding time for 6 preforms is 3 minutes

[0278] The assembly time for connecting 6 tubular tanks to each other is 5 minutes.

[0279] Embodiment 4 (comparative example):

[0280] A tank for use in a vehicle is produced with an internal volume of 61 litres, an external diameter of 400 mm, a length of 0.88 m (including the base) and a burst pressure of 1610 bar.

[0281] The tank is a Type IV tank with composite reinforcement on the outside, weighing 36.7 kg, and a polyethylene leakproof layer on the inside, weighing 5 kg. There is no adhesion between the leakproof layer and the composite reinforcement.

[0282] The composite reinforcement consists of an epoxy matrix and Toray carbon fibers, reference T700 S, with a fiber content of 70% by weight or 59% by volume (the density of the carbon fibers used is 1.8 and the density of the epoxy resin is 1.1). It is manufactured by wet winding: the dry fibers are unwound from the spindle and impregnated with the resin by passing through a bath containing a liquid precursor of the epoxy resin at a speed of 0.8 m / s at room temperature. 4 yarns are wound simultaneously on the liner. Each carbon yarn contains 1200 filaments (carbon yarn 12K) and has a linear density of 0.83 g / m. Taking into account the fiber content of 70% by weight, the linear density of each impregnated yarn is 1.18 g / m. Therefore, at a speed of 0.8 m / s, the parallel winding of all 4 yarns lasts about 2.7 h. This step is followed by polymerization of the resin in an oven at 60°C for 8 h.

[0283] It is thus found that the manufacture of a Type IV tank takes much longer than that of the conformable V tank of Example 3 according to the invention and consumes more composite material, so that the Type IV tank will be significantly heavier and more expensive, since the price of carbon fiber is the main factor in the cost of the tank. It is thus shown that the effectiveness of the composite reinforcement in the Type IV tank is at least 2 times lower than the effectiveness of the composite material constituting the V tank of Example 3: in fact, to contain the same volume of hydrogen (61 liters) while withstanding the same internal pressure of 1600 bar, a Type IV tank made of epoxy carbon composite material requires about 2 times more composite material than a conformable tank made of PPA carbon composite material.

Claims

1. A method of manufacturing a tank, in particular a tank for storing a pressurized fluid, said tank comprising a consolidated and elongated textile element, said method comprising the following steps: (i) producing an unconsolidated and elongated textile preform comprising a plurality of layers of thermoplastic composite tapes, each layer comprising at least one tape wound at a given angle, said preform being produced by means of an apparatus (1), said apparatus (1) comprising: - a support (2) comprising a main longitudinal guide (3) in the X direction, said guide (3) being attached to said support (2); and - at least two modules (4) arranged in series around said guide (3) along said direction X, each module (4) comprising: - a feed crown (5) which surrounds a portion of said guide (3); - a feeding device (6) arranged on the crown (5) suitable for feeding at least one strip (10) to the guide (3) at a winding angle between -90° and 90° with respect to the direction X and at a feeding speed V1, each strip (10) being suitable for being wound at least around the guide (3) or on an upper layer of a strip (10); and - means (15) for driving the crown (5), suitable for rotating the crown (5) around the guide (3) at a rotation speed V2, The method for manufacturing the prefabricated component comprises the following steps: - implementing said feeding device (6) on each said module (4), said feeding device (6) comprising a selected tape (10), said selected tape (10) comprising at least a tape of thermoplastic composite material; - configuring the feed speed V1 and the rotation speed V2 of each of the modules (4) and starting each module (4); - cutting of the elongated element (11) and / or exhaustion of the tape (10); and - recovering the resulting unconsolidated elongated textile preform; Step i) does not include any step of braiding the belt; (ii) consolidating said textile preform obtained in the previous step by heating and cooling said thermoplastic composite material strip, whereby said preform is consolidated and an elongated and consolidated textile element is obtained.

2. The method according to claim 1, wherein: The thermoplastic composite tape comprises: - continuous or discontinuous reinforcing fibers of inorganic material; and - Thermoplastic polymer composition.

3. The method according to claim 2, wherein: The reinforcing fibers of inorganic materials are: - impregnating the core or pre-impregnating it with a thermoplastic polymer composition, or - Blended with thermoplastic polymer fibers.

4. A method according to any one of the preceding claims, wherein: The thermoplastic composite tape comprises continuous fibers impregnated with a composition containing a thermoplastic polymer and has 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, more preferably greater than 120°C, when the polymer is amorphous, and a melting point greater than 150°C when the polymer is semi-crystalline.

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

6. The method according to claim 5, wherein: The polyamide is an aliphatic, cycloaliphatic or semiaromatic polyamide.

7. The method according to claim 6, wherein: The aliphatic polyamide is selected from PA5, PA5-10, PA6, PA66, PA6-10, PA6-12, PA6-18, PA9, PA10-10, PA10-12, PA11, PA12, and mixtures thereof.

8. The method according to claim 7, wherein: The semi-aromatic polyamide is selected from the group consisting of 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, PAMXDT / 10T, PAMPMDT / 4T, PAMPMDT / 6T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PABACT / 4T, PABACT / 10T / 6T, PA11 / 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 PA11 / MPMDT / 10T, PA11 / MXDT / 10T, PA11 / 5T / 10T and their mixtures.

9. A method according to any one of the preceding claims, wherein: The fibers of the thermoplastic composite tape are selected from glass fibers, carbon fibers, basalt fibers or fibers containing basalt.

10. A method according to any one of the preceding claims, wherein: The fibers of the thermoplastic composite tape are unidirectional, ie oriented all along the length of the tape.

11. A method according to any one of the preceding claims, wherein: The composite tape comprises a fiber content between 40% and 70% by volume of the thermoplastic composite tape, preferably between 50% and 60% by volume.

12. A method according to any one of the preceding claims, wherein: The selected tapes (10) also include non-composite tapes (10) of thermoplastic polymers.

13. The method according to claim 12, wherein: The non-composite thermoplastic polymer tapes (10) comprise a smaller mass fraction of the preform than the mass fraction of the thermoplastic composite tapes.

14. The method according to claim 13, wherein: The polymer composition forming the non-composite thermoplastic tape (10) comprises mainly polyamide, preferably semi-crystalline polyamide.

15. The method according to claim 14, wherein: The thermoplastic polymer composition of the thermoplastic composite tape (10) is compatible, in particular identical, to the composition of the non-composite thermoplastic polymer tape (10).

16. A method according to any one of the preceding claims, wherein: The thickness of the tape (10) is between 50 and 300 μm, in particular between 50 and 260 μm, more particularly between 60 and 170 μm.

17. A method according to any one of the preceding claims, wherein: The width of the strip (10) is between 5 mm and 50 mm, in particular between 10 mm and 15 mm.

18. A method according to any one of the preceding claims, wherein: Relative to said direction X, the winding angle of said tape (10) is between +90° and -90°.

19. The method according to claim 18, wherein: The winding angle is + / -54.8° to + / -10°, preferably + / -5°, more preferably + / -1°.

20. A method according to any one of the preceding claims, wherein: The textile preform produced in step i) comprises a variation in cross section, in particular a sequential variation along the direction X.

21. A method according to any one of the preceding claims, wherein: Said step ii) is carried out in a mould, in particular outside said preform, more particularly in a closed mould.

22. A method according to any one of the preceding claims, wherein: During said step ii), pressure is applied by means of a bladder inside said preform.

23. A method according to any one of the preceding claims, wherein: Prior to said step ii), an insert is placed at the end of said preform obtained in said step i), preferably outside the end of said preform.

24. The method according to claim 23, wherein: If appropriate, the insert is made of a composite thermoplastic material.

25. The method according to claims 23 and 24, wherein: In said step ii), said insert is co-consolidated with said strip (10) during said consolidation step ii).

26. Tank, in particular for storing a pressurized fluid, especially hydrogen, comprising at least one textile and consolidated elongated element, said element being obtainable according to the method of claims 1-25.

27. The tank according to claim 26, wherein Each of the consolidated elongated elements is provided at its end with an insert.

28. The tank according to claim 27, wherein The insert is: - an insert closing the elongated and consolidated element, or - An insert with orifices for letting said fluid in and out.

29. A tank as claimed in claims 26 to 28, comprising a plurality of consolidated elongate elements connected in series to each other by connectors.

30. An unconsolidated and elongated textile preform obtainable according to step i) of the method according to claims 1 to 25.

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

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