Method for manufacturing a multilayer fluid storage tank

Abstract

The invention relates to a method for preparing a multilayer storage tank for fluid comprising the steps of: Heating at least one impregnated fibrous material comprising continuous fibers impregnated with at least one thermoplastic composition comprising at least one thermoplastic polymer, by a first infrared heating system or by contact with heating rollers (also called heating packs), to a temperature greater than or equal to the melting temperature or the glass transition temperature of said thermoplastic polymer, depending on whether said polymer is semi-crystalline or amorphous, Passing said heated impregnated fibrous material over one or more pack(s) with a tension measured at the outlet of the last pack of between 0.08 and 42 N / mm per impregnated fibrous material, preferably between 0.4 and 12.5 N / mm, more preferably between 1.7 and 12.5 N / mm, even more preferably between 4 and 12.5 N / mm;Deposition of one or more layer(s) of the impregnated fibrous material obtained in step (ii) onto a support. Figure for the abbreviation: Figure 3;

Description

Title of the invention: Method for manufacturing a multilayer fluid storage tank Scope of the invention

[0001] The present invention relates to a method for manufacturing a multilayer fluid storage tank, preferably a multilayer gaseous fluid storage tank, and the tank that can be obtained by this method. Technical background

[0002] The manufacturing quality of a thermoplastic composite tank and its performance / cost ratio depend on many criteria.

[0003] In the case of manufacturing composites from thermoplastic impregnated strips, there are criteria related to the material health of the material (impregnation quality, control of dimensional parameters etc...) as well as to its nature (type of fibers, type of resin, reinforcement rate etc...).

[0004] Criteria related to the placement of these tapes are also found. In the aeronautical field, for the manufacture of high-performance parts, automated tape laying (ATL) technologies can be used. This family of processes includes several technologies such as fiber placement (AFP), tape winding (for the manufacture of parts with rotating geometries), etc. In these techniques, robots unwind and place tapes of fibrous material(s) comprising fibers impregnated with at least one thermoplastic polymer at very precise locations using a robotic system. This system generally consists of a multi-axis robotic arm with a placement head attached to its end, within which the tapes pass. The head serves to guide these tapes and also to cut them when the robot changes trajectory during the manufacturing of the part.It also generally includes a gripping roller to apply mechanical pressure to the tape during its placement in order to better consolidate it with the composite layers already deposited.

[0005] A variant of these ATL systems is to position the mold of the composite part directly on the robot, the tapes being placed on a reel (or canter) to be unwound, then passing through different fixed heating systems before being wound / deposited on the mold of the part mounted on the robot.

[0006] The robotic deposition system is generally equipped with one or more heating means to heat the tape in order to melt, at least on the surface, the polymer it contains and thus allow it to adhere to the tape or support on which it is deposited.

[0007] Several heating methods can be used: Laser, Diode or LED, UV, hot air source, infrared etc... They heat the tape being deposited and sometimes they also slightly heat the support on which the tapes are deposited to facilitate adhesion and improve the quality of the deposited composite.

[0008] Infrared heating of ribbons is commonly used, particularly for manufacturing large parts such as fluid storage tanks. However, this type of heating, which is very slow compared to laser heating, for example, generally induces complete melting of the ribbon and consequently deconsolidation of said ribbon, leading to the formation of air or water bubbles within the molten polymer matrix. As a result, during the transition to the solid state, i.e., when the temperature drops below the crystallization temperature of the resin, undesirable porosities and a non-homogeneous distribution of the polymer matrix occur. These porosities and this non-homogeneous distribution of the polymer matrix are likely to alter the mechanical properties of the tank, and in particular its pressure resistance.These defects are all the more critical during the tank cycling phases (filling / emptying), potentially initiating cracking of the composite.

[0009] There is therefore a real need for a process for manufacturing a fluid storage tank from impregnated fibrous material (also called composite material) which makes it possible to overcome these disadvantages. Summary of the invention

[0010] A method for manufacturing a fluid storage tank has now been developed which improves the quality of deposition of impregnated fibrous material, and reduces the formation of porosity in said impregnated fibrous material during deposition.

[0011] This is made possible by implementing the impregnated fibrous material on one or more liners, said impregnated fibrous material being: - either heated by infrared radiation prior to or simultaneously with passage over said barriers, or heated by contact with heated rollers (or heated barriers); and - subjected to a tension measured at the last loading of between 0.08 and 42 N / mm per impregnated fibrous material, preferably between 0.4 and 12.5 N / mm, more preferably between 1.7 and 12.5 N / mm, even more preferably between 4 and 12.5 N / mm.

[0012] More specifically, the inventors were able to show that the tension generated by the passage of the impregnated fibrous material over the lugs, in combination with a possible tension applied at the hopper outlet, made it possible to exert pressure on The fibrous material is impregnated in a molten state to eliminate defects, such as the formation of air or water bubbles, before being deposited on the substrate surface. These bubbles can generate porosity and impair the mechanical strength of the resulting product. After the final loading step, the impregnated fibrous material is deposited onto a substrate, preferably heated, notably using infrared heating.

[0013] Thus, the invention relates primarily to a method for preparing a multilayer storage tank for fluid, comprising the steps of: - Heating at least one impregnated fibrous material comprising continuous fibers impregnated with at least one thermoplastic composition comprising at least one thermoplastic polymer, by a first infrared heating system or by contact with heating rollers (also called heating packs), to a temperature greater than or equal to the melting temperature or the glass transition temperature of said thermoplastic polymer, depending on whether said polymer is semi-crystalline or amorphous, - Passing said heated impregnated fibrous material over one or more carriage(s) with a tension measured at the outlet of the last carriage between 0.08 and 42 N / mm per impregnated fibrous material, preferably between 0.4 and 12.5 N / mm, more preferably between 1.7 and 12.5 N / mm, even more preferably between 4 and 12.5 N / mm; - Deposition of one or more layer(s) of the impregnated fibrous material obtained in step (ii) onto a support.

[0014] Preferably, in step ii), said fibrous material passes through at least 2, in particular at least 3 and more preferably at least 4 gates, in particular rotating ones.

[0015] Preferably, step (i) implements an enclosure including an infrared heater.

[0016] Preferably, all the containers are located within said enclosure and optionally have a self-contained cooling system, preferably independent of each other. In one embodiment, some of the containers are located outside said enclosure and have a self-contained heating system, preferably independent of each other, and some of the containers are located within said enclosure and optionally have a self-contained cooling system, preferably independent of each other. In another embodiment, all the containers are located outside said enclosure and have a self-contained heating system, preferably independent of each other.

[0017] In one embodiment, a compression element is attached to the support and applies a compression force of between 0.4 and 25 N / mm per impregnated fibrous material, ideally between 0.4 and 8.5 N / mm, ideally between 0.4 and 2.5 N / mm.

[0018] Preferably, the embrasure(s) have a diameter between 10 mm and 500 mm, preferably between 15 and 60 mm.

[0019] Preferably, the passage of said ribbon over the barrier(s) is carried out with a speed of travel between 0.1 and 600 m / min, in particular between 3 and 60 m / min and preferably between 15 and 50 m / min.

[0020] Preferably, in step (i), the impregnated fibrous material is heated by said first IR heating, to a temperature greater than or equal to:

[0021] at the melting temperature (Tf) if the thermoplastic polymer is semi-crystalline, in particular at a temperature between Tf and Tf + 100°C, preferably between Tf and Tf + 80°C, preferably between Tf + 20°C and Tf + 80°C; or

[0022] - at the glass transition temperature (Tg), if the thermoplastic polymer is amorphous, especially at a temperature between Tg and Tg + 130°C, preferably between Tg and Tg + 100°C.

[0023] Preferably, said at least one impregnated fibrous material is a web of impregnated fibrous material(s) comprising N unit ribbons of fibrous material(s) superimposed and / or joined, said N unit ribbons adhering to each other and being capable of overlapping at least partially, said unit ribbons of fibrous material(s) comprising continuous fibers impregnated with at least one thermoplastic polymer.

[0024] Preferably, the support is chosen from:

[0025] - a chuck, in particular a metal chuck;

[0026] - a tank base including in particular a metallic element, in particular made of aluminum;

[0027] - a sealing layer for the fluid storage tank, in particular for gas; or

[0028] - the fluid storage tank being manufactured comprising a layer internal barrier (or sealing layer) and at least one layer of impregnated fibrous material.

[0029] In one embodiment, the substrate is the sealing layer and during the deposition of the layer of impregnated fibrous material, the temperature of the surface on which the impregnated fibrous material is deposited is:

[0030] in the case where the polymer that mainly makes up the sealing layer is semi-crystalline, between Te - 20°C and Tf + 50°C where Te is the crystallization temperature and Tf is the melting temperature;

[0031] in the case where the polymer that mainly makes up the sealing layer is amorphous, greater than or equal to the Tg, preferably between Tg + 10 and Tg + 100°C.

[0032] This application also relates to a storage tank for a fluid that can be obtained according to the process described above and comprising a layer cohesive sealing with the impregnated fibrous material and characterized by a porosity rate of the impregnated fibrous material layers after deposition of less than 10% preferably less than 5% and even more preferably less than 2%. Brief description of the figures

[0033] To simplify the figures, only one fibrous material is represented, but it should be understood that the invention also covers a process involving several fibrous materials unrolled in parallel and deposited on the support to prepare the reservoir.

[0034] [Fig.1] Fig.1 represents a counter-example of the process according to the invention, in which an impregnated fibrous material (3) is heated in a melting furnace comprising an IR heating system (1) and is then directly deposited, without passing through liners, onto a support (4) included in a second infrared (IR) heating chamber (oven).

[0035] [Fig.2] Fig.2 represents a first embodiment of the process of the invention wherein an impregnated fibrous material (3) is heated in a first IR heating system (1) then passes through heating liners (2) positioned outside the IR oven before being deposited on a support (4) present in a second IR heating system (oven).

[0036] [Fig.3] Fig.3 represents a second embodiment of the process of the invention in which an impregnated fibrous material is heated in a first IR heating system (1) comprising containers (2) before being deposited on a support (4) placed in a second IR heating system (oven).

[0037] [Fig.4] Fig.4 represents a third embodiment of the process of the invention wherein an impregnated fibrous material (3) is heated in a first IR heating system (1) comprising liners (2) and then passes over a 4th heated liner (3) positioned outside the IR oven and in contact with the support itself placed in a second IR heating system (oven).

[0038] [Fig.5] Fig.5 represents the distances (height hl and length dl) between the barriers.

[0039] [Fig.6] Fig.6 represents the morphology of the impregnated fibrous material before heating.

[0040] [Fig.7] Fig.7 represents the morphology of the impregnated fibrous material after passage through the first IR heating system.

[0041] [Fig.8] The [Fig.8] represents the morphology of the ferrule of the reservoir obtained according to the process corresponds to the [Fig.1], comparative example.

[0042] [Fig.9] Fig.9 represents the morphology of the impregnated fibrous material after the passage on the first embarkation in the process shown in [Fig.2].

[0043] [Fig. 10] The [Fig. 10] represents the morphology of the impregnated fibrous material after passing through the 3 hoppers in the process shown in [Fig.2].

[0044] [Fig. 11] The [Fig. 11] represents the morphology of the tank ferrule obtained by implementing the process shown in the [Fig.2].

[0045] [Fig. 12] [Fig. 12] represents the morphology of the impregnated fibrous material after the 3rd embedding in the process shown in [Fig. 3].

[0046] [Fig. 13] The [Fig. 13] represents the morphology of the ferrule of the reservoir obtained by implementing the process shown in the [Fig.3].

[0047] [Fig. 14] The [Fig. 14] represents the morphology of the ferrule of the reservoir obtained by implementing the process shown in the [Fig.4].

[0048] [Fig. 15] Fig. 15 represents a fourth embodiment of the process of the invention in which an impregnated fibrous material (3) passes over 4 heated containers (2), the last of which is in contact with the support itself placed in a second IR heating system (oven).

[0049] [Fig. 16] [Fig. 16] represents the morphology of the tank ferrule obtained by implementing the process shown in [Fig. 15]. Detailed description

[0050] The invention is now described in more detail and in a non-limiting manner in the following description.

[0051] Unless otherwise indicated, all percentages relating to quantities are mass percentages.

[0052] This application relates to a process for preparing a multilayer storage tank for fluid comprising the steps of: i. Heating at least one impregnated fibrous material comprising continuous fibers impregnated with at least one thermoplastic composition comprising at least one thermoplastic polymer, by a first infrared heating system or by contact with heating rollers (also called heating packs), to a temperature greater than or equal to the melting temperature or the glass transition temperature of said thermoplastic polymer, depending on whether said polymer is semi-crystalline or amorphous, ii. Passing said heated impregnated fibrous material over one or more carriage(s) with a tension measured at the outlet of the last carriage between 0.08 and 42 N / mm per impregnated fibrous material, preferably between 0.4 and 12.5 N / mm, more preferably between 1.7 and 12.5 N / mm, even more preferably between 4 and 12.5 N / mm; iii. Deposition of one or more layer(s) of the impregnated fibrous material obtained in step (ii) onto a support.

[0053] The tension measured at the last loading is expressed in N / mm per impregnated fibrous material. Thus, the final measured tension must be multiplied by the width of the fibrous material used and by the number of fibrous materials used. Impregnated fibrous material Fibrous material

[0054] In this description, "fibrous material" means an assembly of reinforcing fibers. The impregnated fibrous material of the present invention is a fibrous material comprising continuous reinforcing fibers and being impregnated with a thermoplastic composition comprising at least one thermoplastic polymer.

[0055] The fibers constituting the fibrous material of the invention are preferably mineral fibers. The fibers can be used alone or in mixtures.

[0056] Among the fibers of mineral origin, we can mention carbon fibers, glass fibers, basalt or basalt-based fibers, silica fibers, or silicon carbide fibers, for example.

[0057] The fibrous material can also be a fabric, braided or woven with fibers.

[0058] It can also correspond to fibers with retaining threads.

[0059] Organic fiber strands can have various weights. They can also have various geometries. The constituent fibers of the fibrous material can also be in the form of a mixture of these reinforcing fibers of different geometries.

[0060] Preferably, the fibrous material consists of continuous fibers selected from glass fibers, carbon fibers, basalt or basalt-based fibers, in particular carbon fibers. It is used in the form of a strand or several strands.

[0061] The term "continuous fibers" means fibers whose aspect ratio, that is to say the ratio between diameter and length, is greater than 1000. The diameter of the fibers can be measured in particular by microscopy.

[0062] Preferably, the fibers are carbon fibers.

[0063] The fibrous material impregnated according to the invention can be in any form, in particular in the form of a ribbon (or tape), a strip or a sheet or a fabric made from an assembly (for example horizontal and / or vertical) of ribbon.

[0064] The term "strip" is used to designate strips of impregnated fibrous material with a width greater than or equal to 400 mm. The term "ribbon" is used for designate ribbons of impregnated fibrous material whose width is less than or equal to 400 mm.

[0065] The fibrous material impregnated according to the invention has a thickness, before infrared heating, of between 50 and 1000 pm, preferably between 50 and 300 pm, preferably between 50 and 200 pm, preferably between 100 and 200 pm.

[0066] The fibrous material impregnated according to the invention can be dried before the implementation of the process of the invention.

[0067] Preferably, the impregnated fibrous material comprises between 40 and 70% by volume of fibers, preferably between 50 and 70%, more preferably between 55 and 70%, even more preferably between 55 and 65% by volume, relative to the total volume of the impregnated fibrous material.

[0068] Preferably, the width of the impregnated fibrous material is between 5 and 300 mm, preferably between 5 and 100 mm, more preferably between 5 and 50 mm. Thermoplastic polymer

[0069] The fibrous material is impregnated with a thermoplastic composition comprising at least one thermoplastic polymer or a mixture of thermoplastic polymers.

[0070] A thermoplastic, or thermoplastic polymer, is defined as a material that is generally solid at room temperature, which may be semi-crystalline or amorphous, and which softens upon an increase in temperature, particularly after passing its glass transition temperature (Tg), and flows at a higher temperature when amorphous, or which may exhibit complete melting upon passing its so-called melting temperature (Tf) when semi-crystalline, and which becomes solid again upon a decrease in temperature below its crystallization temperature (for a semi-crystalline material) and below its glass transition temperature (for an amorphous material). Tg and Tf are determined by differential scanning calorimetry (DSC) according to standards EN 11357-2:2013 and EN 11357-3:2013 respectively.

[0071] Preferably, the thermoplastic composition comprises, relative to the total weight of the composition, at least 50% by weight of thermoplastic polymer or a mixture of thermoplastic polymers, preferably from 70 to 100% by weight.

[0072] Optionally, the thermoplastic composition according to the invention further comprises carbon fillers, in particular carbon black or carbon nanofillers, preferably selected from carbon nanofillers, in particular graphene and / or carbon nanotubes and / or carbon nanofibrils or mixtures thereof. These fillers conduct electricity and heat, and consequently improve the lubrication of the polymer matrix when heated.

[0073] Optionally, said thermoplastic composition comprises at least one additive, in particular selected from a catalyst, an antioxidant, a thermal stabilizer, a UV stabilizer, a light stabilizer, a lubricant, a filler, a plasticizer, a flame retardant, a nucleating agent, a chain extender and a dye or a mixture thereof.

[0074] According to another embodiment, the thermoplastic composition of the invention may further comprise liquid crystal polymers or cyclized poly(butylene terephthalate), or mixtures containing them, such as the CBT100 resin marketed by CYCLICS CORPORATION. These compounds notably allow the polymer matrix to be made more fluid in the molten state, for better penetration into the core of the fibers.

[0075] Thermoplastic polymers can be selected from:

[0076] - polymers and copolymers of the aliphatic polyamide (PA) family, cycloaliphatic or semi-aromatic PAs (also known as polyphthalamides (PPA));

[0077] - polyureas, in particular aromatic ones;

[0078] - polymers and copolymers of the acrylic family such as polyacrylates, and more specifically polymethyl methacrylate (PMMA) or its derivatives;

[0079] - polymers and copolymers of the polyarylether ketone (PAEK) family such as poly(ether ether ketone) (PEEK), or polyarylether ketones (PAEKK) such as poly(ether ketone) (PEKK) or their derivatives;

[0080] - aromatic polyetherimides (PEI);

[0081] - polyarylsulfides, in particular polyphenylene sulfides (PPS);

[0082] - polyarylsulfones, in particular polyphenylene sulfones (PPSU);

[0083] - polyolefins, in particular polypropylene (PP);

[0084] - polylactic acid (PLA);

[0085] - polyvinyl alcohol (PVA);

[0086] - fluorinated polymers, in particular poly(vinylidene fluoride) (PVDF), or the polytetrafluoroethylene (PTFE) or polychlorotrifluoroethylene (PCTFE), and mixtures thereof.

[0087] Preferably, the thermoplastic polymer is a polymer or copolymer from the polyamide family.

[0088] The nomenclature used to define polyamides is described in ISO1874-1:2011 "Plastics - Polyamide (PA) materials for molding and extrusion - Part 1: Designation", in particular on page 3 (tables 1 and 2) and is well known to those skilled in the art.

[0089] Advantageously, said thermoplastic polymer is:

[0090] - an aliphatic polyamide selected from polyamide 6 (PA-6), polyamide 11 (PA-11), polyamide 12 (PA-12), polyamide 66 (PA-66), polyamide 46 (PA-46), polyamide 610 (PA-610), polyamide 612 (PA-612), polyamide 1010 (PA-1010), polyamide 1012 (PA-1012), or a mixture thereof or a copolyamide thereof,

[0091] - a semi-aromatic polyamide, optionally modified by urea units, in particular a semi-aromatic polyamide of formula X / YAr, as described in EPI505099, in particular a semi-aromatic polyamide of formula A / XT in which A is selected from a motif obtained from an amino acid, a motif obtained from a lactam and a motif corresponding to the formula (diamine in Ca).(diacid in Cb), with a representing the number of carbon atoms of the diamine and b representing the number of carbon atoms of the diacid, a and b each being between 4 and 36, advantageously between 9 and 18, the (diamine in Ca) motif being selected from aliphatic diamines, linear or branched, cycloaliphatic diamines and alkylaromatic diamines and the (diacid in Cb) motif being selected from aliphatic diacids, linear or branched, cycloaliphatic diacids and aromatic diacids; X.T denotes a motif obtained from the polycondensation of a Cx diamine and terephthalic acid, with x representing the number of carbon atoms of the Cx diamine, x being between 6 and 36, advantageously between 9 and 18, in particular a polyamide of formula A / 6T, A / 9T, A / 10T or A / 1T, A being as defined above, in particular a PA 6 / 6T polyamide, a PA 66 / 6T, a PA 61 / 6T, a PA MPMDT / 6T, a PA MXDT / 6T, a PA PA11 / 10T, a PA 11 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, a PA BACT / 10T, a PA BACT / 6T, PA BACT / 10T / 6T, a PA 11 / BACT / 10T, PA 11 / BACT / 6T, PA 11 / MPMDT / 10T and PA 11 / MXDT / 10T, and block copolymers, notably polyamide / polyether (PEBA).

[0092] T corresponds to terephthalic acid, MXD corresponds to m-xylylene diamine, MPMD corresponds to methylpentamethylene diamine and BAC corresponds to bis(aminomethyl)cyclohexane.

[0093] The process according to the invention can utilize several impregnated fibrous materials in parallel, allowing, in particular, the parallel deposition, in step (iii), of several layers of impregnated fibrous material. For example, the process of the invention utilizes from 1 to 50 strips of impregnated fibrous material in parallel, preferably from 1 to 20, preferably from 1 to 8, preferably from 1 to 4. These impregnated fibrous materials may be identical or different; when they are different, the fibers and / or the thermoplastic polymer are different, or the proportions of fibers and thermoplastic polymer are different.

[0094] Each of the impregnated fibrous materials can be unwound at an average speed of between 0.1 and 600 m / min, preferably between 3 and 60 m / min, more preferably between 15 and 50 m / min. Preferably, the impregnated fibrous materials are unwound, preferably using a reeling device (i.e., a (e.g., a canter) equipped with a brake, for example, so as to optionally apply tension to each impregnated fibrous material. This tension is preferably between 0.4 and 8.5 N / mm per impregnated fibrous material, more preferably between 0.8 and 4.5 N / mm per impregnated fibrous material, and more preferably between 1.2 and 4.2 N / mm per impregnated fibrous material. This optional tension at the canter outlet is added to the tension induced by passing over the carriage(s) to obtain a tension measured at the outlet of the last carriage of between 0.08 and 42 N / mm per impregnated fibrous material, preferably between 0.4 and 12.5 N / mm, more preferably between 1.7 and 12.5 N / mm, and even more preferably between 4 and 12.5 N / mm.

[0095] Preferably, when several impregnated fibrous materials are used in the process, a guidance system is preferably used to put all the impregnated fibrous materials on the same plane and at the same altitude, preferably at the altitude of the 1st loading.

[0096] Preferably, the impregnated fibrous material is tangent to the first embedding. Heating of the impregnated fibrous material (step i)

[0097] The process of the invention includes a step (i) of heating the impregnated fibrous material by an infrared heating system or by passing over heated rollers.

[0098] The infrared heating system is, for example, an infrared furnace. It may consist of one or more infrared lamps. The distance between the lamps and the impregnated fibrous material is between 1 and 50 cm, preferably between 1 and 10 cm. The surface density of the infrared heating system is between 20 and 600 kW / m², preferably 20 to 200 kW / m².

[0099] Advantageously, this step allows the impregnated fibrous material to be brought to a temperature greater than or equal to the melting temperature of the thermoplastic polymer in the thermoplastic composition of the fibrous material, in the case of a semi-crystalline polymer, or greater than the glass transition temperature in the case of an amorphous polymer, so that it can be deposited onto the substrate and adhere to said substrate or, where applicable, to the previous layer of fibrous material. Upon exiting the infrared heating system, the impregnated fibrous material is considered to be in a molten state.

[0100] Preferably, the infrared heating system is characterized by a wavelength between 780 nm and 1400 mm for short infrared preferred for carbon fibers, or between 1400 and 3000 mm, preferably between 780 nm and 1400 mm.

[0101] In step (i), the impregnated fibrous material is heated to a higher temperature: - at the melting temperature (Tf) if the thermoplastic polymer is semi-crystalline, preferably at a temperature between Tf and Tf + 100°C, preferably between Tf and Tf + 80°C, preferably between Tf + 20°C and Tf + 80°C; or - at the glass transition temperature (Tg), if the thermoplastic polymer is amorphous, preferably at a temperature between Tg and Tg + 130°C, preferably between Tg and Tg + 100°C. Embarkation (step ii)

[0102] The process of the invention employs at least one mold. Advantageously, the transition of the impregnated fibrous material to a molten state on the mold(s) reduces the formation of porosity in said impregnated fibrous material. Advantageously, the porosity of the layer of impregnated fibrous material obtained by the claimed process is less than 10%, preferably less than 6%, more preferably less than 4%, and more particularly less than 2%.

[0103] In the context of the present invention, "frame" means any system on which the impregnated fibrous material has the possibility of moving; the impregnated fibrous material in the molten state rests partially or totally on the surface of said frame.

[0104] The container(s) of the invention may be of any shape. If the process uses several containers, these may be identical or different in terms of the material constituting the containers, their shape, diameter, length, etc. For example, the containers may be made of steel that has undergone a hard chrome surface treatment.

[0105] The bearings may be fixed or rotating; they are preferably rotating (and therefore have a shape of revolution), preferably with a controlled rotational speed (by brakes and / or motors, for example). Rotating bearings may be co-rotating or counter-rotating; they are preferably all counter-rotating. In one operating mode, some may be co-rotating and others counter-rotating. The tangential velocity at the surface of the bearings is, in absolute value (if a counter-rotating velocity is considered negative), between 1 and 50%, preferably between 1 and 10% of the flow speed of the impregnated fibrous materials.

[0106] Within the framework of the present invention, the sluices are said to be in co-rotation (and conversely in contra-rotation) if they rotate by generating a tangential velocity in the same direction (and inversely different) to that of the flow of the impregnated fibrous materials.

[0107] Preferably, the liners are compression rollers, in particular concave, convex or cylindrical, preferably cylindrical compression rollers. The liners of the cylindrical compression roller type may have a diameter between 10 mm and 500 mm, preferably between 15 and 60 mm.

[0108] The containers according to the invention preferably have an arithmetic mean roughness (Ra) of between 0.2 and 2 µm. The arithmetic mean roughness is measured with a roughness tester according to ISO 4288:1996.

[0109] The process involves at least one hopper, preferably at least two hoppers, preferably at least three hoppers, more preferably at least four hoppers, for example between 4 and 10 hoppers.

[0110] In the case where the process includes several containers, these are preferably mounted in series.

[0111] In the case where the process includes several shorings, particularly cylindrical shorings, the difference in height hl between each of the shoring centers is preferably zero (all the shorings are therefore at the same height), and otherwise it is at most 20 cm, preferably between 1 and 10 cm, and / or the horizontal distance dl between each of the shoring centers is preferably at least 5 cm, preferably between 5 and 50 cm. It should be noted that, depending on the roller diameters used, not all configurations of hl and dl are physically feasible because they would require the rollers to interpenetrate.

[0112] The swages apply mechanical tension to the impregnated fibrous material. This tension results from solid-on-solid friction of the fibrous material in contact with the swages. The tension generated by the individual swages can be amplified if an initial tension is applied at the swage outlet.

[0113] When there are several shorings, the impregnated fibrous material preferably passes alternately under one shoring and then over the next shoring and so on.

[0114] Advantageously, the tension generated by the shoring(s), combined with the arrangement of the shorings, the geometry of the shorings (in particular for example the value of Ra, the diameter), the unwinding speed, the rotation or not of the shorings and / or the initial tension at the outlet of the shoring makes it possible to obtain a tension value measured at the outlet of the last shoring of between 0.08 and 42 N / mm per impregnated fibrous material, preferably between 0.4 and 12.5 N / mm, more preferably between 1.7 and 12.5 N / mm, even more preferably between 4 and 12.5 N / mm.

[0115] Advantageously, the process of the invention may include a compression element in contact (or attached) with the support or reservoir being formed. This compression element makes it possible to apply a compressive force to the substrate; this compressive force can ideally be between 0.4 and 25 N / mm per impregnated fibrous material, ideally between 0.4 and 8.5 N / mm, ideally between 0.4 and 2.5 N / mm.

[0116] The compressive force is expressed in N / mm per impregnated fibrous material. Thus, the total compressive force must be multiplied by the width of the fibrous material used and by the number of fibrous materials used.

[0117] When a compression element is attached to the support or the tank being formed, then the tension measurement according to the invention is taken at the last attachment point before the compression element.

[0118] The voltage measurement at the output of the last carriage is carried out using a strain gauge placed at the end of this carriage.

[0119] The temperature at the level of the containers is preferably controlled to be between 50 and 450°C, preferably between 150 and 450°C, preferably between 200 and 450°C, preferably between 200 and 400°C. The temperature of each container can be controlled independently, and the temperature at each container may be the same or different. The containers may thus include a temperature control system that includes a heating system and a cooling system. The temperature is measured on the surface of the containers either by contact, for example using an integrated or flush-mounted thermocouple, or by contact, for example using a pyrometer or a thermal imaging camera.Preferably, the containers that are in the heating enclosure of stage (i) include a cooling system and the containers positioned outside the heating enclosure of stage (i) include a heating system.

[0120] In one embodiment, steps (i) and (ii) may be totally or partially simultaneous or totally dissociated. Thus:

[0121] - in an embodiment, in which steps (i) and (ii) are totally simultaneous, the heating of the fibrous material impregnated in step (i) is carried out in an enclosure comprising an infrared heating system and all the containers are placed in said enclosure;

[0122] - in an embodiment in which steps (i) and (ii) are totally Simultaneously, the heating of the fibrous material impregnated in step (i) is carried out in an enclosure comprising an infrared heating system and all the containers are placed in said enclosure and each container has a cooling system allowing its temperature to be regulated;

[0123] - in an embodiment in which steps (i) and (ii) are partially Simultaneously, the heating of the impregnated fibrous material in step (i) is carried out in an enclosure comprising an infrared heating system; some of the containers are placed in said enclosure and at least one container is located outside said enclosure. The container(s) outside said enclosure have(s) a temperature control system. The container(s) placed in the heating system may optionally have a cooling system for temperature control;

[0124] - in an embodiment in which steps (i) and (ii) are totally Separated, the barriers are all placed after the heating system (infrared or heating roller) and have their own temperature regulation system;

[0125] - in an embodiment in which steps (i) and (ii) are totally When separated, the liners are all placed after the heating system (infrared or heating roller) and have their own temperature regulation system, and the last liner is in contact with the surface of the tank. Preferably, in such a case, the compressive force applied by the liner attached to the support or the tank being formed is between 0.4 and 25 N / mm per impregnated fibrous material, ideally between 0.4 and 8.5 N / mm, ideally between 0.4 and 2.5 N / mm;

[0126] - in an embodiment in which steps (i) and (ii) are partially simultaneous, the heating of the impregnated fibrous material in step (i) is carried out in an enclosure comprising an infrared heating system, part of the liners are placed in said enclosure and at least one liner is outside said enclosure and the last liner outside said enclosure is attached to the support. Preferably, in such a case the compressive force applied by the liner attached to the support or the tank being formed is between 0.4 and 25 N / mm per impregnated fibrous material, ideally between 0.4 and 8.5 N / mm, ideally between 0.4 and 2.5 N / mm;

[0127] - in one embodiment the impregnated fibrous material is heated on heated rollers and the last roller is attached to the support.

[0128] The compression force can be measured by any method known to a person skilled in the art, and in particular by means of a pressure gauge on the axis of the robot holding the substrate or tank being manufactured and measures the force applied by the pressure roller on the tank, the value is then normalized by the width of the impregnated fibrous material.

[0129] Preferably, the barriers, when placed in the enclosure comprising the infrared heating system, are arranged so that the distance between The infrared emission source and the surface over which the impregnated fibrous material passes should be between 2 and 40 cm, preferably between 2 and 10 cm, preferably between 5 and 10 cm. Preferably, the infrared lamps are positioned below and above the barriers. Depositing onto a medium (step iii)

[0130] The process of the invention includes a step (iii) of depositing one or more layers of impregnated fibrous material onto a support to provide the multilayer reservoir. Preferably, the process includes depositing 2 to 500 layers of impregnated fibrous material, preferably 20 to 500 layers, preferably 50 to 500 layers, preferably 50 to 300 layers.

[0131] The support can be of any type allowing the manufacture of a tank for the storage of fluid, in particular gas. The support can in particular be:

[0132] - a chuck, in particular a metal chuck; in particular a steel chuck or made of aluminum, preferably aluminum.

[0133] - a tank base including in particular a metallic element, in particular made of steel or aluminum, preferably aluminum;

[0134] - an internal barrier layer of the fluid storage tank, in particular of gas also known as liner; or

[0135] - the fluid storage tank being manufactured comprising a layer internal barrier (or sealing layer or liner) and at least one layer of impregnated fibrous material or a layer of impregnated fibrous material supported by a sealing layer of the fluid storage tank, in particular of gas.

[0136] Preferably, the support is:

[0137] - an internal barrier layer (or sealing layer or liner) of the tank fluid storage, particularly of gases; or

[0138] - the fluid storage tank being manufactured comprising a layer internal barrier and at least one layer of impregnated fibrous material.

[0139] It must be understood that the process of the invention covers the deposition of the first layer of impregnated fibrous material on the support and also, following the progress of the process, the deposition of subsequent layers of impregnated fibrous material on the layers of impregnated fibrous material already deposited on the support (this embodiment corresponds to the case where the support is the fluid storage tank being manufactured comprising an internal barrier layer and at least one layer of impregnated fibrous material).

[0140] The internal barrier layer of the fluid storage tank, particularly for gases, also called the sealing layer, is preferably made of a composition comprising predominantly at least one semi-crystalline thermoplastic polyamide having a Tf, measured according to ISO 11357-3:2013, less than or equal to 280°C, preferably less than or equal to 260°C, preferably less than or equal to 230°C, and more particularly less than or equal to 200°C.

[0141] The term “majority” means that said at least one polyamide is present at more than 50% by weight relative to the total weight of the composition.

[0142] Advantageously, said at least one major polyamide is present at more than 60% by weight, in particular at more than 70% by weight, particularly at more than 80% by weight, more particularly greater than or equal to 90% by weight relative to the total weight of the composition.

[0143] This composition may also include shock modifiers and / or additives. However, the barrier layer must not release harmful compounds into the stored gas, nor contain particles likely to reduce its permeability. Therefore, those skilled in the art will ensure that the additives in the composition are chosen, as well as their concentration, in such a way as to prevent this release.

[0144] The additives can be selected from an antioxidant, a heat stabilizer, a UV absorber, a light stabilizer, a lubricant, an inorganic filler, a flame retardant, a nucleating agent, a plasticizer, a colorant, carbon black and carbon nanofillers.

[0145] Advantageously, said composition consists mainly of one or more semi-crystalline thermoplastic polyamides as defined above, 0 to 5% by weight of shock modifier, 0 to 5% by weight of additives, the sum of the constituents of the composition being equal, by weight, to 100%.

[0146] In one embodiment of the tank according to the invention, only one major polyamide is present in the sealing layer.

[0147] In order to make them absorbent, it is known to add various additives to them, including for example carbon black, which gives the polymer a black color and allows it to better absorb radiation suitable for welding.

[0148] The semi-crystalline thermoplastic polyamide can be a homopolyamide or a copolyamide.

[0149] Advantageously, the semi-crystalline thermoplastic polyamide included in the sealing layer has a ratio of the number of carbon atoms to the number of nitrogen atoms in the polyamide denoted C / N greater than or equal to 5, preferably greater than or equal to 8, in particular greater than or equal to 9, and more particularly greater than or equal to 10.

[0150] Preferably, the semi-crystalline thermoplastic polyamide is selected from PA410, PA 56, PA59, PA510, PA512, PA513, PA 514, PA6, PA 66, PA 69, PA610, PA612, PA614, PA618, PA1010, PA1012, PApipl0, PApipl2, PA1014, PA1018, PA1210, PA1212, PA1214, PA1218, PAU and PA12, preferably PA410, PA510, PA 69, PA610, PA 512, PA612, PA 514, PA614, PA618, PA1010, PA1012, PA1014, PA1018, PA1214, PA1218, PAU and PA12, PA 11 / 5T, PA 11 / 6T and PA11 / 10T, PA 11 or PA 12, and their mixture, are very preferred.

[0151] The motif content 11 in the semi-aromatic copolyamides is adjusted so that the copolyamide has a melting temperature less than or equal to 280°C, preferably less than or equal to 260°C, preferably less than or equal to 230°C, and more particularly less than or equal to 200°C.

[0152] In a preferred embodiment, said semi-crystalline thermoplastic polyamide is an aliphatic semi-crystalline thermoplastic polyamide.

[0153] Preferably, the semi-crystalline thermoplastic polyamide included in the sealing layer is an aliphatic semi-crystalline thermoplastic polyamide, in particular selected from PA410, PA 56, PA59, PA510, PA512, PA513, PA 514, PA6, PA 66, PA 69, PA610, PA612, PA614, PA618, PA1010, PA1012, PApipl0, PApipl2, PA1014, PA1018, PA1210, PA1212, PA1214, PA1218, PAU and PA12, preferably PA6, PA66, PA410, PA510, PA 69, PA610, PA 512, PA612, PA 514, PA614, PA618, PA PA1010, PA1012, PA1014, PA1018, PA1214, PA1218, PAU and PA12, very preferably PA 11 or PA12, and their mixture.

[0154] In particular, the aliphatic semi-crystalline thermoplastic polyamide is selected from polyamide 11 (PAU), polyamide 12 (PA12), polyamide 1010 (PA1010), polyamide 1012 (PA 1012), in particular PA11 and PA 12.

[0155] The composition constituting the sealing layer comprises a polyamide as defined above predominantly or a mixture of these polyamides defined above. This mixture is predominantly present in the composition.

[0156] Preferably, in the case where the polymers composing mainly the sealing layer and the matrix of the composite directly in contact with the sealing layer are semi-crystalline, the difference between the melting temperature (Tf) of the thermoplastic polymer of the impregnated fibrous material and the temperature (Tf) of the thermoplastic polymer of the sealing layer is between 0°C and 120°C, preferably from 0°C to 80°C.

[0157] Preferably, in the case where the polymers composing mainly the sealing layer and the matrix of the composite directly in contact with the sealing layer are amorphous, the difference between the glass transition temperature (Tg) of the thermoplastic polymer of the impregnated fibrous material and the thermoplastic polymer of the sealing layer is between 0 and 170°C, preferably from 0 to 80°C.

[0158] Preferably, in the case where the polymer mainly composing the sealing layer is semi-crystalline and the polymer mainly composing the matrix of the composite directly in contact with the sealing layer is amorphous, the difference between the glass transition temperature (Tg) of the thermoplastic polymer the component of the composite matrix and the temperature (Tf) of the thermoplastic polymer of the sealing layer is between 0 and 50°C, preferably from 0 to 20°C.

[0159] The impregnated fibrous material is deposited on the support in a molten state, allowing good adhesion of the different layers of impregnated fibrous material to each other and to the support.

[0160] To ensure that the impregnated fibrous material is in a molten state when deposited on the substrate, it is preferably necessary to control the temperature of said impregnated fibrous material. Various solutions can be implemented to achieve this:

[0161] - a check of the distance between the last boarding and the support, preferably this distance is between 0 (contact between the fitting and the support) and 30cm, preferably between 0 and 10cm, preferably between 1 and 10cm;

[0162] - an infrared heating element, for example, placed between the last embarkation and support to maintain adequate thermal insulation before removal;

[0163] - temperature regulation of the last onboard unit when it is in contact with the surface of the support.

[0164] Preferably, at the time of deposition of the impregnated fibrous material on the support, said impregnated fibrous material is at a temperature between Tf and Tf + 80°C, preferably between Tf + 30°C and Tf + 80°C, when said at least one thermoplastic polymer is a semi-crystalline polymer or between Tg and Tg + 100°C, if said at least one thermoplastic polymer is amorphous.

[0165] When the substrate is the sealing layer of the fluid storage tank, during the deposition of the layer of impregnated fibrous material, the temperature of the surface on which the impregnated fibrous material is deposited is preferably: - in the case where the polymer that mainly makes up the sealing layer is semi-crystalline, between Te - 20°C and Tf + 50°C where Te is the crystallization temperature and Tf is the melting temperature; - in the case where the polymer that mainly makes up the sealing layer is amorphous, greater than or equal to the Tg, preferably between Tg + 10 and Tg + 100°C.

[0166] Preferably, to reach these temperatures, the deposition step (iii) is carried out in a thermostatically controlled chamber, preferably using an infrared heating device.

[0167] To ensure optimal bonding between the layer of impregnated fibrous material and the substrate, it is preferable to add a compression element, attached to the tank being formed, which allows a compressive force to be applied during deposition. The compressive force can ideally be between 0.4 and 25 N / mm² per impregnated fibrous material, ideally between 0.4 and 8.5 N / mm², ideally between 0.4 and 2.5 N / mm².

[0168] This compression element can be of any type, including a cylindrical bar, a roller, a disc, etc. In a particular embodiment, this compression element is one of the supports mentioned above. This embodiment is particularly suitable for cases where the deposition angle between the impregnated fibrous material and the axis of the support is small, in particular less than 70° (the angle 0° being considered as being represented by the axis of rotation of the deposition support and 90° consisting of deposition by overlapping tapes concentrically), ideally when the angle is less than 55°. Reservoir

[0169] The tank according to the invention can be a tank for the mobile storage of gas, in particular hydrogen, i.e. on a truck for the transport of gas, in particular hydrogen, on a car for the transport of gas, in particular hydrogen and in particular the supply of hydrogen to a fuel cell for example, on a train for the supply of hydrogen or on a drone for the supply of hydrogen, but it can also be a stationary storage tank of gas, in particular hydrogen, at a station for the distribution of gas.

[0170] The term "gas" designates a constituent selected from air, oxygen (O2), nitrogen (N2), carbon dioxide (CO2), carbon monoxide (CO), argon (Ar), helium (He), methane (CH4), ethylene (C2H4), propane (C3H8), butane (C4HiO), liquefied natural gas (LNG), liquefied petroleum gas (LPG), hydrogen (H2), in particular hydrogen.

[0171] The tank according to the invention comprises at least one sealing layer as defined above and at least one reinforcing layer made up of layers of impregnated fibrous material, the sealing layer being cohesive with the at least one reinforcing layer.

[0172] The present invention also relates to the fluid storage tank obtainable by the process of the invention. This tank differs from tanks obtained by other processes because it is of type 4.5 or V. In other words, the sealing layer is cohesive with the composite reinforcement, or alternatively, there is no sealing layer, the composite reinforcement directly acting as the sealing layer. Preferably, this tank is large, typically with a diameter greater than 150 mm. Furthermore, thanks to the use of one or more liners according to the invention, the consolidation of the composite layers is excellent, and the residual porosity, measured on the composite layer, is low and typically less than 10%, preferably less than 5%, and even more preferably less than 2%. The porosity can be measured by microscopic analysis or according to the ISO 14127:2008 standards, particularly for carbon fibers, or ISO 1172:1999, particularly for glass fibers.

[0173] Two layers are considered non-cohesive when, by micrographic cross-section analysis or by non-destructive C-scan analysis, delamination of the layers is observed. Examples

[0174] In all the examples and counterexamples described below, a unidirectional impregnated fibrous material, with a width of 1.27 cm, is used to manufacture a tank by winding said fibrous material around a polyamide 11 liner.

[0175] The impregnated fibrous material used is composed of 55% by volume of Hyosung H2550 carbon fibers impregnated with a polyamide 11 (PAU) or polyphthalamide (PPA) resin, as applicable. When polyamide 11 is used, the trade name of the fibrous material is UDX® PAU. When polyphthalamide is used, the trade name of the fibrous material is UDX® PPA.

[0176] In all the figures the liner is shown in cross-section perpendicular to its axis, i.e. a cross-section taken from the part of the liner which allows the manufacture of the tank's shell (i.e. its cylindrical part).

[0177] The polymer compositions present in the impregnated fibrous material before passing through the IR oven have viscosities of 10 Pa.s at 230°C for the PA11 resin and 150 Pa.s at 300°C for the PPA resin (formulation 11 / BACT / 10T).

[0178] In all examples the impregnated fibrous material is conveyed from a winder (not shown in the figures) to the liner at a speed of 15 m / min.

[0179] The infrared oven is regulated at a temperature of 230°C or 300°C, respectively, when the polymer of the impregnated fibrous material is PA1 or PPA. This temperature allows the polymer of the impregnated fibrous material to melt. The heated impregnated fibrous material then passes over a series of 3 or 4 indentations with a diameter of 40 mm, all indentations being horizontally aligned (hl=0 mm) and spaced 50 mm apart (dl=50 mm). The external diameter of the liner is 400 mm. The indentations in the examples are fixed. The liner is placed in an open thermal chamber which allows the temperature of the liner surface to be regulated and then, after the first layer of impregnated fibrous material has been deposited, the temperature of the n-1 layer to be regulated.In examples 2 to 4, the liner is cooled from the inside (to 210°C when using UDX® PA11 and 250°C when using UDX® PPA), which heats its outer surface to a temperature sufficient for welding the different layers. In example 5, using a roller in contact with the liner allows the first layers of impregnated fibrous material to be deposited without heating the liner with an oven. Once these first layers have been deposited, the oven is turned on, as well as the internal cooling system of the liner, to finish the deposition of the different layers.

[0180] In the comparative example, there is no embarge in or out of the IR furnace.

[0181] In all cases, a tension is applied to the impregnated fibrous material at the outlet of the canter, which is multiplied by the presence of the barriers.

[0182] Passing through the melting furnace leads to a deconsolidation of the impregnated fibrous material. The examples below demonstrate that the tension induced by the various shorings generates a pressure at the shoring contact points which allows the impregnated fibrous material to reconsolidate.

[0183] In the following examples, the microscopy images are obtained using a Keyence VHX-7100 optical microscope, observation with a total magnification of x40. Comparative example 1

[0184] In this example no embargo is used, as shown in [Fig.1].

[0185] The fibrous material used in this example is UDX® PAU.

[0186] The tension applied to the impregnated fibrous material before it enters the furnace (i.e., at the furnace outlet) is 0.39 N / mm² and the feed speed is 15 m / min. The temperature of the impregnated fibrous material at the IR furnace outlet is 230°C. The temperature of the oven in which the liner is positioned is regulated so that the surface temperature of the liner when the first layer of impregnated fibrous material is deposited, and then the temperature of layer n-1, is 210°C.

[0187] Fig. 6 shows that the fibers of the fibrous material impregnated before passing through the IR oven are perfectly impregnated with the polymer, the porosity is very low and is not detectable on the section observed in optical microscopy at magnification of x40.

[0188] In the absence of embedding, the fibrous material impregnated at the exit of the IR furnace is significantly deconsolidated, as evidenced by the presence of porosities ([Fig.7]) which did not exist ([Fig.6]) before heating.

[0189] The part produced in this comparative example according to the process of [Fig.1] leads to a very porous part (porosity > 10%) as can be seen on the section of this composite part observed in optical microscopy at magnification of x40 ([Fig.8], liner not visible). Example 1 according to the invention

[0190] The fibrous material used in this example is UDX® PAU.

[0191] In this example, three heating packs are positioned between the oven outlet and the liner, as shown in [Fig. 2]. The oven temperature is 230°C. The packs are heated to 230°C by means of an electric heating cartridge placed inside said packs. The tension applied to the fibrous material The impregnated material before entering the oven (i.e., at the canter exit) has a tensile strength of 0.3 N / mm² and a feed speed of 15 m / min. The tension measured on the impregnated fibrous material at the exit of the last canter is 7.5 N / mm² of impregnated fibrous material. The temperature of the oven in which the liner is positioned is regulated so that the surface temperature of the liner when the first layer of impregnated fibrous material is deposited, and then the temperature of the n-1 layer, is 210°C.

[0192] The morphology of the impregnated fibrous material before entering the IR oven is the same as in comparative example 1 ([Fig.6]), because it has not yet been heated: the fibers of the impregnated composite material are perfectly impregnated with resin, the porosity is very low and undetectable on the section observed in optical microscopy at x40 magnification.

[0193] Upon exiting the IR furnace, the impregnated fibrous material is deconsolidated in accordance with what is observed in comparative example 1.

[0194] After passing through the first swaging stage, the impregnated fibrous material exhibits a reduced porosity ([Fig. 9]) compared to that observed directly at the furnace outlet ([Fig. 7]), even though the applied tension at the furnace outlet is lower (0.3 N / mm N vs. 0.39 N / mm). The addition of two further swaging stages further improves the reconsolidation of the impregnated fibrous material by reducing its porosity ([Fig. 10]), demonstrating the effectiveness of the swaging stages in reconsolidating the impregnated fibrous material after complete polymer melting.

[0195] The composite part obtained has a reasonably low porosity rate of 4%, as can be seen on the cross-section of this composite part observed under optical microscopy at x40 magnification ([Fig.11]). Example 2: The invention:

[0196] The fibrous material used in this example is UDX® PAU.

[0197] The process implemented in this example corresponds to that of [Fig. 3] with 4 jams in the IR furnace.

[0198] The tension applied to the impregnated fibrous material at the outlet of the furnace is 0.3 N / mm. The tension measured on the impregnated fibrous material at the outlet of the last tray is 10 N / mm of impregnated fibrous material. The trays in the furnace are not heated independently but are heated via the IR furnace and have a cooling system to regulate their temperature at 230°C. The temperature of the oven in which the liner is positioned is regulated so that the temperature of the liner when the first layer of impregnated fibrous material is deposited, and then the temperature of layer n-1, is 210°C.

[0199] Fig. 12 shows that the cumulative effect of the 4 obstructions present in the furnace, the initial tension at the furnace outlet (0.3 N / mm) and the IR furnace temperature of 230°C allows for a virtually perfect reconsolidation of the impregnated fibrous material after total melting of the polymer: the porosity is very low and not or very little detectable on the section observed in optical microscopy at magnification of x40.

[0200] The composite part obtained has a very low porosity rate of 2%, as can be seen on the cross-section of this composite part observed under optical microscopy at magnification of x40 ([Fig. 13]). Example 3 according to invention #:

[0201] The fibrous material used in this example is UDX® PPA.

[0202] The process implemented in this example corresponds to that of [Fig.4].

[0203] This process uses 4 containers, 3 of which are positioned in the IR furnace heated to 300°C. The fourth container, positioned outside the IR furnace, is heated to 300°C by means of an electric heating cartridge placed inside the container. Furthermore, this fourth container is in contact with the surface of the tank being manufactured, in the cylindrical section of the tank.

[0204] The tension applied to the impregnated fibrous material at the canter outlet is 0.3 N / mm. The tension measured on the impregnated fibrous material at the last liner not in contact with the support or tank being formed is 7.5 N / mm of impregnated fibrous material. The temperature of the oven in which the liner is positioned is regulated so that the liner temperature when the first layer of impregnated fibrous material is deposited, and then the temperature of layer n-1, is 250°C. The last liner in contact with the support or tank being formed applies a compressive force of 0.4 N / mm of impregnated fibrous material.

[0205] Figure 14 shows a cross-section of the resulting composite part, observed under an optical microscope at 40x magnification. Part of the tank was produced by helical winding of the impregnated fibrous material at angles between 15° and 30°. Bringing the last sprue exiting the IR furnace into contact with the surface of the tank being manufactured, and applying a force of 0.4 N / mm of impregnated fibrous material to this last sprue in contact with the tank, made it possible to apply sufficient contact pressure to obtain excellent consolidation of the layers, particularly those corresponding to the helical winding. The resulting porosity is very low (2%). Example 4 according to invention#:

[0206] The fibrous material used in this example is UDX® PAU.

[0207] The process implemented is shown in [Fig. 15] and employs four heated bar ends, heated by means of an electric heating cartridge placed inside the bars, at a temperature of 230°C. Furthermore, the fourth bar end is in contact with the surface of the tank being manufactured, in the cylindrical part of the tank by applying a compressive force of 0.4 N / mm of impregnated fibrous material.

[0208] The tension applied to the tape at the exit of the liner is 0.3 N / mm. The tension measured on the impregnated fibrous material at the exit of the last liner not in contact with the support or the tank being formed is 7.5 N / mm of impregnated fibrous material. The temperature of the oven in which the liner is positioned is regulated so that the temperature of the liner when the first layer of impregnated fibrous material is deposited, and then the temperature of layer n-1, is 210°C.

[0209] Figure 16 shows a cross-section of the composite part obtained, observed under an optical microscope at x40 magnification. Part of the reservoir obtained by helical winding of the impregnated fibrous material at angles between 15 and 30°. Bringing the last roll (the swaging) into contact with the surface of the reservoir and applying a compressive force of 0.4 N / mm of impregnated fibrous material to this last swaging in contact with the reservoir made it possible to apply sufficient contact pressure to obtain excellent consolidation of the layers, particularly those corresponding to the helical winding.

[0210] Table 1 below summarizes all the implementation conditions of the examples.

[0211] [Tables 1] Ex compa 1 EX 1 EX 2 EX 3 EX 4 Polymer PAU PAU PAU 11 / BACT / 10T PAU Fibers 55% by volume of Hyosung H2550 carbon fibers 55% by volume of Hyosung H2550 carbon fibers 55% by volume of Hyosung H2550 carbon fibers 55% by volume of Hyosung H2550 carbon fibers 55% by volume of Hyosung H2550 carbon fibers Exit tension 0.39 N / mm 0.3 N / mm 0.3 N / mm 0.3 N / mm 0.3 N / mm Spinning speed 15m / min 15m / min 15m / min 15m / min 15m / min Process Oven, no dams Oven + 3 dams Oven + 4 heating elements in 1st oven Oven + 3 heating elements in the oven + 1 heating element 4 heating elements, 1 of which is in contact Heating element in contact with the reservoir (see Tfour 230°C 230°C 230°C 300°C) - Heating element - 230°C 230°C 300°C 230°C Rotation speed of the barriers None None None None None Distance between the point of passage of the fibrous materials and the infrared heating source 5cm 5cm 5cm 5cm 5cm Ra of the barriers 0.4pm 0.4pm 0.4pm 0.4pm 0.4pm Power density of the IR used above the barriers 118kW / m2 118kW / m2 118kW / m2 118kW / m2 118kW / m2 Voltage (output barriers) 7.5 N / mm of impregnated fibrous material 10 N / mm of impregnated fibrous material 7.5 N / mm of impregnated fibrous material 7.5 N / mm of impregnated fibrous material Step iii) T liner = 210°C CT liner = 210°C CT liner = 210°C CT liner = 250°C CT liner = 210°C Compression force 0.4 N / mm of impregnated fibrous material 0.4 N / mm of impregnated fibrous material Results Fig 8 Porosity > 10% Fig 11 Porosity 4% Fig 13 Porosity 2% Fig 14 Porosity 2% Fig 16 Porosity 2%

Claims

Demands

1. A method for preparing a multilayer storage tank for fluid comprising the steps of: i. Heating at least one impregnated fibrous material comprising continuous fibers impregnated with at least one thermoplastic composition comprising at least one thermoplastic polymer, by a first infrared heating system or by contact with heating rollers (also called heating packs), to a temperature greater than or equal to the melting temperature or the glass transition temperature of said thermoplastic polymer, depending on whether said polymer is semi-crystalline or amorphous; ii. Passing said heated impregnated fibrous material over one or more pack(s) with a tension measured at the outlet of the last pack of between 0.08 and 42 N / mm per impregnated fibrous material, preferably between 0.4 and 12.5 N / mm, more preferably between 1.7 and 12.5 N / mm, even more preferably between 4 and 12.5 N / mm; iii.Deposition of one or more layer(s) of the impregnated fibrous material obtained in step (ii) onto a support.

2. A method according to claim 1, wherein in step ii), said fibrous material passes through at least 2, in particular at least 3 and more preferably at least 4 gates, in particular rotating ones.

3. A method according to claim 1 or 2, wherein step (i) employs an enclosure comprising an infrared heater.

4. A method according to claim 3, wherein all the containers are present in said enclosure and optionally have an autonomous cooling system, preferably independent of each other.

5. A method according to claim 3, wherein part of the containers are outside said enclosure and have an autonomous heating system preferably independent of each other and part of the containers are present in said enclosure and optionally have an autonomous cooling system preferably independent of each other.

6. A method according to claim 3, wherein all the containers are outside said enclosure and have an autonomous heating system, preferably independent of each other

7. A method according to any one of claims 1 to 6, comprising a compression element attached to the support and applying a compression force of between 0.4 and 25 N / mm per impregnated fibrous material, ideally between 0.4 and 8.5 N / mm, ideally between 0.4 and 2.5 N / mm.

8. A method according to any one of the preceding claims, wherein the hopper(s) have a diameter between 10 mm and 500 mm, preferably between 15 and 60 mm.

9. A method according to any one of the preceding claims, wherein the passage of said ribbon over the shoring or shorings is carried out with a speed of travel between 0.1 and 600 m / min, in particular between 3 and 60 m / min and preferably between 15 and 50 m / min.

10. A method according to any one of the preceding claims, wherein in step (i), the impregnated fibrous material is heated by said first IR heating, to a temperature greater than or equal to: - the melting temperature (Tf) if the thermoplastic polymer is semi-crystalline, in particular to a temperature between Tf and Tf + 100°C, preferably between Tf and Tf + 80°C, preferably between Tf + 20°C and Tf + 80°C; or - the glass transition temperature (Tg), if the thermoplastic polymer is amorphous, in particular to a temperature between Tg and Tg + 130°C, preferably between Tg and Tg + 100°C.

11. A method according to any one of the preceding claims, wherein said at least one impregnated fibrous material is a web of impregnated fibrous material(s) comprising N unit ribbons of fibrous material(s) superimposed and / or joined, said N unit ribbons adhering to each other and being capable of at least partially overlapping, said unit ribbons of fibrous material(s) comprising continuous fibers impregnated with at least one thermoplastic polymer.

12. A method according to any one of the preceding claims, wherein the support is selected from: - a mandrel, in particular a metal mandrel; - a tank base including in particular a metal element, in particular made of aluminum; - a sealing layer of the fluid storage tank, in particular of gas; or - the fluid storage tank being manufactured comprising an internal barrier layer (or sealing layer) and at least one layer of impregnated fibrous material.

13. A method according to claim 12, wherein the support is the sealing layer and during the deposition of the layer of impregnated fibrous material, the temperature of the surface on which the impregnated fibrous material is deposited is: - in the case where the polymer mainly composing the sealing layer is semi-crystalline, between Te - 20°C and Tf + 50°C where Te is the crystallization temperature and Tf is the melting temperature; - in the case where the polymer mainly composing the sealing layer is amorphous, greater than or equal to Tg, preferably between Tg + 10 and Tg + 100°C.

14. A fluid storage tank that can be obtained according to the process as defined in claims 1 to 13, comprising a sealing layer cohesive with the impregnated fibrous material and characterized by a porosity rate of the impregnated fibrous material layers after deposition of less than 10%, preferably less than 5%, and even more preferably less than 2%.