Method for manufacturing a strip of composite material intended to form a tubular structure and corresponding installation

Abstract

Method for manufacturing a composite material strip intended to form a tubular structure and corresponding installation The method comprises: - butt application of end regions (64A, 64B) of disjointed strip parts (60A, 60B), - application of heat and pressure to achieve a welded joint between the end regions (64A, 64B); At least one end region (64A, 64B) has a rear zone (72A, 72B) and a front zone (66A, 66B) projecting from the rear zone (72A, 72B), the front zone (66A, 66B) being delimited by two lateral edges (68, 70) each having at least one point located away from a respective extension of each lateral edge (74, 76) of the rear zone (72A, 72B). The front area (66A) of an end region (60A) of a first part of strip (60A) is located opposite an end region (64B) of a second part of strip (60B) when the end regions (64A, 64B) are butted together.Figure for the abbreviation: figure 2.

Description

Title of the invention: Method for manufacturing a strip of composite material intended to form a tubular structure and corresponding installation

[0001] The present invention relates to a method of manufacturing a strip of composite material intended to form a tubular structure, the method comprising the following steps:

[0002] - end-to-end application of end regions of disjointed strip parts, each strip portion being formed from a polymer matrix and fibers or film embedded in the matrix,

[0003] - application of heat and pressure to make a welded joint between the end regions.

[0004] Such a strip of composite material is for example intended to form a tubular structure of a pipe, in particular a thermoplastic composite pipe (“Thermoplastic Composite Pipe” or TCP), or a hybrid flexible pipe (“Hybrid Flexible Pipe” or HFP).

[0005] Such tubular structures are manufactured in particular by winding at least one strip of composite material around a support, and by welding the successive windings of strip together with a high-temperature weld, for example carried out using a laser.

[0006] Such a technique is particularly suitable when the composite strip comprises a polyetheretherketone (PEEK) matrix which provides the tubular structures with excellent mechanical properties, in conjunction with the reinforcing fibers it contains.

[0007] Such pipes thus have the advantage of being light, while being very resistant to the internal pressure located in the pipe, or to the external pressure applied in the pipe.

[0008] Composite strips intended for the formation of such internal structures are currently produced by manufacturing several strip parts in one piece, then butt welding the strip parts together, to produce a strip of greater length, which is compatible with the length of the pipe to be produced.

[0009] A weld joint is formed between the free ends of successive strip portions. In this regard, WO2021 / 094718 describes a method for making welds on composite strip portions. The end regions of the strip portions are brought end to end and are welded together after applying heat.

[0010] Even if the welding is carried out with great care, any significant variation in thickness at the junction can lead, when the windings of the strip are exposed to the laser in order to produce the tubular structure, to a local increase in temperature at the junction, which can reach more than 550°C.

[0011] At this temperature, flash or local combustion phenomena may appear. Combustion debris, contaminants, or holes are then formed around the junction. In addition, crack initiations and / or adhesion defects may appear in this area.

[0012] These phenomena occurring at the junctions between the strip parts are therefore troublesome, insofar as the maximum achievable length of a unitary strip part is generally of the order of 500 m, which implies several junctions along the strip, if the latter has a substantial length.

[0013] An object of the invention is therefore to provide a method for manufacturing a strip of composite material from unitary strip parts assembled end to end, without adhesive or glue, in which the subsequent welding of the composite strip to form a tubular structure is not substantially affected by the presence of the junctions between the unitary strip parts.

[0014] For this purpose, the invention relates to a manufacturing method as defined above, characterized in that at least one end region has a rear zone in which the lateral edges of the strip portion are parallel to each other, and a front zone projecting from the rear zone, the front zone being delimited by two lateral edges each having at least one point, in particular at least one segment, placed away from a respective extension of each lateral edge of the rear zone, between the respective extensions of each lateral edge of the rear zone,

[0015] the front zone of an end region of a first strip portion being located opposite an end region of a second strip portion during the end-to-end application of the end regions.

[0016] The method according to the invention may comprise one or more of the following characteristics, taken in isolation or in any technically possible combination:

[0017] - the application of heat and pressure involves the induction heating of a heating region of a metal support on which the end regions of the strip parts are arranged;

[0018] - the method comprises arranging an induction coil opposite the region heating the metal support, and the circulation of a variable electric current in the induction coil to generate heat by Joule effect by currents induced in the heating region;

[0019] - the method comprises moving a pressure application wedge on the heating region, and applying pressure to the end regions of the parts of strip between the metal support and the shim;

[0020] - when applying the end regions end to end, at least one side edge of the front area is an inclined side edge, the angle of inclination of the inclined side edge relative to the longitudinal axis of the strip portion in the end region is between 20° and 80°, in particular between 30° and 60°, even more in particular between 35° and 55°;

[0021] - when applying the end regions end to end, the front area of ​​the region end comprises an inclined side edge and an additional inclined side edge, the additional inclined side edge being inclined relative to the longitudinal axis of the strip portion at an angle of inclination opposite to the angle of inclination of the inclined side edge relative to the longitudinal axis of the strip portion;

[0022] - the additional inclined side edge intersects with the inclined side edge at a point end of the strip part;

[0023] - each end region has a rear area in which the side edges of the strip portion are parallel to each other, and a front area projecting from the rear area, the front area being delimited by two lateral edges each having at least one point, in particular at least one segment, placed away from a respective extension of each lateral edge of the rear area, between the respective extensions of each lateral edge of the rear area, the front area of ​​an end region of a first strip portion being located opposite the rear area of ​​an end region of a second strip portion when the end regions are applied end to end;

[0024] - applying heat and pressure to weld the end regions between it is carried out without application of material, in particular without application of a film to the surface of each end region;

[0025] - when applying the end regions end to end, the overlap between the end region of a first strip portion and the end region of a second strip portion, measured along the longitudinal axis of each end region, is greater than 10 mm, and is in particular between 15 mm and 30 mm;

[0026] - the matrix is ​​made of a polymer chosen from PEK (polyetherketone), PEEK (polyetheretherketone), PEEKK (polyetheretherketoneketone), PEKK (polyetherketoneketone), PEKEKK (polyetherketoneetherketoneketone), PAI (polyamide-imide), PEI (polyether-imide), PSU (polysulfone), PPSU (polyphenylsulfone), PES (polyethersulfone), PAS (polyarylsulfone), PPE (polyphenylene ether), PPS (polyphenylene sulfide), LCP (liquid crystal polymers), PPA (polyphthalamide), their copolymers and / or their mixtures, and wherein the fibers are chosen from carbon fibers, glass fibers, aramid fibers, and / or basalt fibers, the fibers advantageously forming a matt, or in which the film is a polyketone yarn, particularly unfilled PEEK (polyetheretherketone).

[0027] The invention also relates to the use of at least one strip of composite material produced by the manufacturing method as defined above to form, advantageously by winding and heating, a tubular structure, in particular a tubular structure of a flexible pipe.

[0028] The invention also relates to an installation for manufacturing a strip of composite material intended to form a tubular structure, the installation comprising:

[0029] a supply or manufacturing station suitable for supplying disjointed strip portions, each strip portion being formed from a polymer matrix and fibers embedded in the matrix,

[0030] a welding station comprising a support having a heating region intended for the end-to-end application of the end regions, and a device for applying heat and pressure to produce a welded junction between the end regions,

[0031] characterized in that the supply and manufacturing station comprises a cutting apparatus configured to form at least one end region having a rear zone in which the lateral edges of the strip portion are parallel to each other, and a front zone projecting from the rear zone, the front zone being delimited by two lateral edges each having at least one point, in particular at least one segment, placed away from a respective extension of each lateral edge of the rear zone, between the respective extensions of each lateral edge of the rear zone.

[0032] The installation according to the invention may comprise one or more of the following characteristics, taken in isolation or in any technically possible combination:

[0033] - the support is a metal support, the device for applying heat and pressure being suitable for heating by induction the heating region of the metal support on which the end regions of the strip parts are arranged, the device for applying heat and pressure comprising an induction coil placed opposite the heating region of the metal support, and a source of variable electric current suitable for supplying the induction coil to generate heat by Joule effect by currents induced in the heating region;

[0034] - the heat and pressure application device comprises a movable wedge applying pressure to the heating region, suitable for applying pressure to the end regions of the strip portions between the metal support and the shim;

[0035] - the cutting device comprises a base defining a groove for receiving a strip portion, and a cutting wedge, mounted to move relative to the base between a loading / unloading position for a strip portion and a cutting position for the strip portion, the cutting apparatus advantageously comprising guides for moving the cutting wedge.

[0036] The invention will be better understood on reading the following description, given solely by way of example, and made with reference to the appended drawings, in which:

[0037] - [Fig.l] [Fig.l] is a schematic view of a strip of composite material obtained by the manufacturing process according to the invention;

[0038] - [Fig.2] [Fig.2] is a schematic view of two composite strip parts intended to be welded together end to end when implementing the method according to the invention, each strip part having a free end region in the shape of a point;

[0039] - [Fig.3] [Fig.3] is a partial perspective schematic view of a substation welding of a first installation for manufacturing composite strips according to the invention;

[0040] - [Fig.4] [Fig.4] is a schematic view of a block diagram representing a installation for manufacturing a flexible pipe including a tubular structure manufactured from the composite strip of [Fig.l];

[0041] - [Fig.5] [Fig.5] is a schematic view of a laser welding station for the strip composite manufactured by the process according to the invention;

[0042] - [Fig.6] [Fig.6] is a partially exploded perspective view of an example of flexible pipe comprising a tubular structure made from a plurality of composite strips obtained by the method according to the invention; and

[0043] - [Fig.7] [Fig.7] is a schematic perspective view of a cutting apparatus for the production of parts of composite strips intended to be welded together.

[0044] A method according to the invention is intended to manufacture a strip 2 made of composite material, an example of which is partially shown in [Fig. 1] and which will subsequently be designated by the term “composite strip”.

[0045] The composite strip 2 is intended to be wound and welded to produce a tubular structure 4, in particular an internal tubular structure 4 of a flexible fluid transport pipe 10, an example of which is visible in [Fig.6].

[0046] The flexible pipe 10 is for example a thermoplastic composite pipe (“Thermoplastic Composite Tube” or TCP) or a hybrid flexible pipe (“Hybrid Flexible Pipe” or HFP) in the example of [Fig.6].

[0047] The tubular structure is for example a tubular structure 4 for reinforcing the flexible pipe 10.

[0048] The flexible pipe 10 comprises a central section 12 illustrated in part on the [Fig.6]. It comprises, at each of the axial ends of the central section 12, an end cap (not visible).

[0049] With reference to [Fig. 6], the pipe 10 delimits an internal passage 13 for the circulation of a fluid, advantageously a petroleum fluid. The internal passage 13 extends along an axis A-A', between the upstream end and the downstream end of the pipe 10. It opens out through the end pieces

[0050] The flexible pipe 10 is intended to be arranged across a body of water in a fluid exploitation installation, in particular hydrocarbons. The body of water is, for example, a sea, a lake or an ocean. The depth of the body of water at the level of the fluid exploitation installation is, for example, between 500 m and 4000 m. The fluid exploitation installation comprises a surface assembly and a bottom assembly (not shown) or two surface assemblies which are advantageously connected to each other by the flexible pipe 10.

[0051] The surface assembly is for example floating. It is advantageously formed by a floating production, storage and offloading unit called FPSO (Floating Production, Storage and Offloading), a floating unit dedicated to liquefied natural gas called FLNG (Floating Liquified Natural Gas), a semi-submersible platform or an offloading buoy. Alternatively, the surface assembly is a fixed rigid structure of the "jacket" type or an oscillating structure secured to the seabed which may be for example a TLP (Tension Leg Platform).

[0052] In this example, the flexible pipe 10 is a partially or totally submerged flexible riser pipe which connects the bottom assembly to the surface assembly. Alternatively, the flexible pipe 10 is totally submerged in the body of water and connects, for example, two bottom assemblies (not shown) together.

[0053] Another variant consists of a flexible pipe 10 partially submerged in the body of water and connecting, for example, two surface assemblies (typically an unloading buoy and an FPSO). This is particularly the case for flexible lines of the OOL type (“Oil Offloading Line” in English).

[0054] As illustrated by [Fig.6], the pipe 10 delimits a plurality of concentric layers around the axis A-A', which extend continuously along the central section 12 to the end pieces located at the ends of the pipe.

[0055] In the example of [Fig.6], the pipe 10 comprises at least one internal tubular sheath 20 based on polymer material advantageously constituting a pressure sheath, and the tubular reinforcement structure 4, applied around the tubular sheath 20 and being linked to it. As a variant, the pipe 10 is devoid of an internal tubular sheath 20, the tubular reinforcement structure 4 then being sealed.

[0056] The pipe 10 further advantageously comprises a plurality of tensile armor plies 24, 25 arranged externally relative to the tubular reinforcement structure 4 while not being connected to the tubular reinforcement structure 4.

[0057] Advantageously, and depending on the desired use, the pipe 10 further comprises anti-wear layers 26, interposed between the tubular reinforcement structure 4 and the tensile armor plies 24, 25, as well as within the tensile armor plies 24, 25. It further advantageously comprises a reinforcing tape 28, wound around the tensile armor plies 24, 25 and an external sheath 30, intended for the protection of the pipe 10.

[0058] In a known manner, the tubular sheath 20 is intended to confine in a sealed manner the fluid transported in the passage 13. The tubular sheath 20 also has the function of protecting the tubular reinforcement structure 4 against abrasion linked to the presence of abrasive particles, for example sand, within the fluid transported in the passage 13.

[0059] The tubular sheath 20 is formed from a polymer material, preferably thermoplastic. For example, the polymer forming the tubular sheath 20 is based on a polyolefin such as polyethylene, based on a polyamide such as PA11 or PA12, or based on a fluorinated polymer such as polyvinylidene fluoride (PVDF).

[0060] Alternatively, the tubular sheath 20 is formed from a high-performance polymer such as PEK (polyetherketone), PEEK (polyetheretherketone), PEEKK (polyetheretherketoneketone), PEKK (polyetherketoneketone), PEKEKK (polyetherketoneetherketoneketone), PAI (polyamide-imide), PEI (polyether-imide), PSU (polysulfone), PPSU (polyphenylsulfone), PES (polyethersulfone), PAS (polyarylsulfone), PPE (polyphenylene ether), PPS (polyphenylene sulfide), LCP (liquid crystal polymers), PPA (polyphthalamide) and / or mixtures thereof or in a mixture with PTFE (polytetrafluoroethylene) or PFPE (perfluoropolyether).

[0061] The thickness of the tubular sheath 20 is for example between 1 mm and 20 mm.

[0062] The tubular sheath 20 is formed from a tube made of polymer material, a strip made of assembled polymer material, or an impregnated polymer mat.

[0063] When the tubular sheath 20 is formed from a tube, it is advantageously obtained by extrusion of a thermoplastic tube chosen in particular from the polymers mentioned above.

[0064] When the tubular sheath 20 is formed from a strip of assembled polymer material, it is advantageously produced by extruding and winding thermoplastic strips of a polymer as described above. Preferably, the turns of a first layer are joined (edge ​​to edge without overlap) and the turns of an upper layer are arranged so as to have an overlap of two lower adjacent strips ensuring the sealing of the tubular sheath 20.

[0065] According to the preferred embodiment, the flexible pipe 10 is devoid of an internal carcass, and it is designated by the English term “smooth bore”. The internal surface of the tubular sheath 20 directly delimits the internal passage 13.

[0066] According to a variant not shown, the flexible pipe comprises an internal carcass located inside the tubular sheath 20, and it is designated by the English term “rough bore”. The internal carcass has the function of increasing the crushing resistance of the flexible pipe, and it is formed for example from a profiled metal strip, wound in a spiral. The turns of the strip are advantageously stapled to each other, which makes it possible to absorb the crushing forces.

[0067] In the example shown in [Fig. 6], the flexible pipe 10 comprises an internal armor layer 24, and an external armor layer 25 around which the outer sheath 30 is arranged.

[0068] Each armor layer 24, 25 comprises longitudinal armor elements 50 wound at long pitch around the axis A-A' of the pipe.

[0069] By "long pitch wound" is meant that the absolute value relative to the A-A' axis of the helix angle is less than 50°, and is typically between 25° and 45°.

[0070] The armor elements 50 of a first ply 24 are generally wound at an opposite angle relative to the armor elements 50 of a second ply 25. Thus, if the winding angle relative to the axis A-A' of the armor elements 50 of the first ply 24 is equal to + q>, q> being between 25° and 45°, the winding angle relative to the axis A-A' of the armor elements 50 of the second ply 25 arranged in contact with the first ply 24 is for example - q>, with q> between 25° and 45°.

[0071] The armor elements 50 are for example formed by metal wires. Alternatively, the armor elements 50 are formed by flat composite wires or ribbons reinforced with carbon fibers.

[0072] Since the tubular reinforcement structure 4 may have low tensile strength and tend to elongate under the effect of axial forces, the armor plies 24, 25 absorb the axial forces and thus prevent the tubular reinforcement structure 4 from elongating.

[0073] The outer sheath 30 is intended to prevent the permeation of fluid from the outside of the flexible pipe 10 towards the inside. It is advantageously made of a polymer material, in particular based on a polyolefin, such as polyethylene, based on a polyamide, such as PAU or PA 12, or based on a fluorinated polymer such as polyvinylidene fluoride (PVDF).

[0074] The thickness of the outer sheath 30 is for example between 5 mm and 15 mm.

[0075] Each anti-wear layer 26 is formed for example of PA (polyamide), PE (polyethylene), PVDF (polyvinylidene fluoride), PEEK (polyetheretherketone), PEKK (polyetherketoneketone). An anti-wear layer 26 is disposed between the tubular reinforcement structure 4 and the first tensile armor ply 24. Another anti-wear layer 26 is placed between each pair of armor plies 24, 25, advantageously as indicated in API Standard 17J, 4th edition May 2014.

[0076] The reinforcing tape 28 is formed, for example, from a high-strength anti-buckling layer. This layer is, for example, made of aramid. The tape is wound around the outermost armor ply 25, between the armor ply 25 and the outer sheath 30, advantageously as indicated in API Standard 17J, 4th edition May 2014.

[0077] In this example, the tubular reinforcement structure 4 is applied directly to the tubular sheath 20. It is assembled on the tubular sheath 20 to form an assembly linked with the tubular sheath 20.

[0078] The tubular reinforcement structure 4 is here a composite structure. It comprises at least one, preferably a plurality of laminated composite reinforcement layers, and optionally, an anti-delamination layer interposed between at least two reinforcement layers.

[0079] Each laminated reinforcing layer comprises a superposition of reinforcing composite layers. The thickness of each composite layer is generally between 0.10 mm and 0.30 mm, for example between 0.12 mm and 0.17 mm, or between 0.22 mm and 0.27 mm.

[0080] In the example shown in [Fig.6], each composite reinforcement layer comprises a polymer matrix 40 and reinforcing fibers 42 embedded in the matrix 40. As a variant, at least one composite reinforcement layer comprises a film embedded in the polymer matrix 40.

[0081] Preferably, the matrix 40 is formed from a polymer, in particular a thermoplastic polymer. The polymer of the tubular sheath 20 is advantageously of the same nature as that of the matrix 40. By "of the same nature", it is meant, within the meaning of the present invention, that the polymer of the tubular sheath 20 and the polymer of the matrix 40 are capable of melting and forming an intimate mixture, without phase separation, after cooling.

[0082] For example, the polymer forming the matrix 40 is based on a polyolefin such as polyethylene, based on a polyamide such as PA11 or PA 12, or based on a fluorinated polymer such as polyvinylidene fluoride (PVDF).

[0083] Alternatively, the matrix 40 is formed from a high-performance polymer such as PEK (polyetherketone), PEEK (polyetheretherketone), PEEKK (polyetheretherketoneketone), PEKK (polyetherketoneketone), PEKEKK (polyetherketoneetherketoneketone), PAI (polyamide-imide), PEI (polyether-imide), PSU (polysulfone), PPSU (polyphenylsulfone), PES (polyethersulfone), PAS (polyarylsulfone), PPE (polyphenylene ether), PPS (polyphenylene sulfide), LCP (liquid crystal polymers), PPA (polyphthalamide) and / or their mixtures or in a mixture with PTFE (polytetrafluoroethylene) or PFPE (perfluoropoly ether).

[0084] The reinforcing fibers 42 are for example carbon fibers, glass fibers, aramid fibers, and / or basalt fibers.

[0085] The reinforcing fibers 42 generally have a maximum tensile strength greater than 2 GPa, advantageously greater than 3 GPa and for example between 3 GPa and 6 GPa, as measured at 23°C according to Standard ASTM D885M - 10A(2014)el.

[0086] In the present application, the terms “maximum tensile strength” and “tensile strength” have the same meaning and designate the ultimate tensile strength measured during a tensile test applied in the longitudinal direction of the reinforcing fibers.

[0087] Furthermore, the reinforcing fibers 42 advantageously have a tensile modulus greater than 50 GPa, for example between 70 GPa and 500 GPa, in particular between 50 GPa and 100 GPa for glass fibers, between 100 GPa and 500 GPa for carbon fibers and between 50 GPa and 200 GPa for aramid fibers, as measured at 23°C according to Standard ASTM D885M - 10A(2014)el.

[0088] In the present application, the terms "tensile modulus", "Young's modulus" and "tensile modulus of elasticity" have the same meaning and designate the modulus of elasticity measured during a tensile test.

[0089] The density of the reinforcing fibers 42 is generally between 1.4 g / cm3 and 3.0 g / cm3.

[0090] The reinforcing fibers 42 are for example arranged unidirectionally in the matrix 40. They are then parallel to each other. Alternatively, the reinforcing fibers 42 are crossed in two orthogonal directions, or are arranged randomly in the matrix (not shown).

[0091] The diameter of the reinforcing fibers 42 is for example less than 100 microns, and is notably between 4 microns and 10 microns for carbon reinforcing fibers.

[0092] Preferably, each composite reinforcing layer of the tubular structure 4 is formed from a winding of at least one composite strip 2 manufactured by the method according to the invention and an example of which is visible in [Fig.l].

[0093] Each composite strip 2 has several layers of fibers 42 embedded in an elongated matrix 40. It has a length greater than at least 10 times its width and at least 10 times its thickness.

[0094] For example, the length of each composite strip 2 is greater than 100 m and is generally between 100 m and 4500 m. The width of each composite strip 2 is in particular between 6 mm and 50 mm. The thickness of each composite strip 2 is advantageously between 0.1 mm and 1 mm.

[0095] Each composite strip 2 thus has, at 23°C, a tensile modulus greater than 10 MPa, in particular between 30 GPa and 170 GPa, as measured by Standard NF EN 2561, January 1996, an elongation at break greater than 0.3%, in particular between 1% and 5%, as measured by Standard NF EN 2561, January 1996, and a maximum tensile strength greater than 100 MPa, and in particular between 350 MPa and 3500 MPa as measured by Standard NF EN 2561, January 1996.

[0096] Advantageously, each composite strip 2 comprises a PEEK or PVDF matrix reinforced by unidirectional carbon fibers oriented parallel to the longitudinal axis of the strip.

[0097] As will be seen below, during the production of each reinforcing layer, the or each composite strip 2 is wound in a helix around the axis A-A' of the tubular sheath 20, and is heated to cause the partial melting of the matrix 40, and the bonding with the successive turns of the composite strip 2, and / or with the adjacent layers which may be other reinforcing layers, anti-delamination layers or the tubular sheath 20.

[0098] The absolute value of the winding helix angle y of each composite strip 2 relative to the axis A-A' of the pipe 10 is for example between 50° and 85°, preferably between 55° and 80°. This ensures elongation of the composite under the effect of the internal pressure, and adequate cooperation with the armor plies 24, 25.

[0099] The combination of a winding angle y of the composite strips 2 with an absolute value of between 50° and 85°, advantageously between 55° and 80°, preferably between 60° and 80°, with a winding angle q> of the armor elements 50 with an absolute value of between 25° and 45°, prevents the elongation of the tubular reinforcement structure 4 by compensation effect produced by the armor plies 24, 25.

[0100] The optimal combination between the winding angles y, q> drastically reduces the stresses in the tubular assembly formed by the internal sheath 20 and the tubular reinforcement structure 4, and therefore the thickness necessary to resist the bending, internal pressure and / or crushing (“collapse”) forces.

[0101] Furthermore, thanks to the axial stiffness of the tubular reinforcement structure 4, the tensile armor plies 24, 25, in cooperation with the tubular reinforcement structure 4, better resist axial compression under the external pressure conditions of the deep seabed.

[0102] Furthermore, the angle q> of winding of the armor elements 50 with an absolute value between 25° and 45°, taken in combination with the angle y of winding of the composite strips 2 with an absolute value between 50° and 85°, allows compression of the tubular reinforcement structure 4, reducing the minimum bending radius (MBR).

[0103] The admissible tensile deformation at the extrados of the tubular assembly formed by the internal sheath 20 and the tubular reinforcement structure 4 is greater than 1%, advantageously greater than 2%, preferably greater than 3%. This deformation induces the winding radius compatible with most manufacturing and installation equipment.

[0104] According to the invention, with reference to [Fig. 1], the composite strip 2 is formed from a plurality of strip parts 60A, 60B which are assembled together end to end by welding to produce a junction 62.

[0105] The number of strip parts 60A, 60B joined end to end to form a strip 2 is for example greater than or equal to 2, and is in particular between 2 and 20.

[0106] The number of strip parts 60A, 60B may be equal to 2, in particular when the strip 2 breaks during manufacture or if a visible defect in the strip 2 is noticed when the machine is stopped.

[0107] The number of strip parts 60A, 60B may be greater, in particular when manufacturing a strip 2 of great length, for example greater than 350 m, and in particular of the order of 1000 m. In this case, at least 3 strip parts 60A, 60B of the order of 300 m are assembled.

[0108] As illustrated by [Fig.2], each strip portion 64A, 64B comprises a polymer matrix 40, and reinforcing fibers 42, as described above.

[0109] Each strip portion 60A, 60B has an end region 64A, 64B intended to be applied to the end region 64B, 64A of another strip portion 60B, 60A to form the junction 62 by welding.

[0110] In the example illustrated by [Fig.2], each end region 64A, 64B comprises a male front zone 66A, 66B having at least one edge 68, 70 inclined relative to a longitudinal axis F-F' of the strip portion 60A, 60B. It further has a rear zone 72A, 72B having lateral edges 74, 76 parallel to each other and parallel to the axis F-F', the rear zone 72A, 72B being intended to be brought into contact with the front zone 66B, 66A of another strip portion 60B, 60A.

[0111] As will be seen below, the superposition of two end regions 64A, 64B having a male front zone 66A, 66B surprisingly makes it possible, despite the increase in thickness compared to a male-female splice, to nevertheless obtain an assembly which retains adequate flexibility for the winding and unwinding of the strip 2.

[0112] The excess thickness is distributed in a symmetrical manner and reaches its maximum at an imaginary line 71 which is the intersection of the two male front zones 66A and 66B. This excess thickness is however much less than in the case of an overlap of end regions without a bevel. Furthermore, the shear stress decreases towards the imaginary line 71 and increases up to the tip of the front zone 66A, 66B.

[0113] In this example, the length of the end region 64A, 64B is greater than 5 mm, in particular greater than 10 mm, and is for example between 15 mm and 25 mm. This length corresponds to the length of the junction 62 on the composite strip 2 obtained after welding.

[0114] Preferably, each front zone 66A, 66B has a length H between 1 / 3 of the width L of the rear zone 72A, 72B and the width L of the rear zone 72A, 72B.

[0115] This length H is notably between 5 mm and 15 mm, notably between 8 mm and 12 mm.

[0116] The width L is advantageously between 10 mm and 30 mm, in particular 12 mm, 18 mm, 22 mm or 25 mm.

[0117] Thus, each junction 62 has a minimal excess thickness while sufficiently preserving the tensile strength and the curvature during installation.

[0118] As will be seen below, such a configuration keeps the energy of the laser beam intended for the assembly of the tubular reinforcement structure 4 substantially constant despite a local excess thickness.

[0119] This unexpectedly avoids varying the energy of the laser beam following a change in the thickness of the strip 2 and therefore causing a variation in the heating temperature of the strip 2 which can repeatedly reach 550°C.

[0120] Problems related to overheating or underheating are therefore largely avoided. It is known that the slightest overheating can generate flashes, or conversely, the slightest underheating can cause insufficient fusion of the strip (unconsolidated or stuck, therefore delamination or bubbling).

[0121] Another surprising advantage of the superposition of the end regions 64A, 64B having male front zones 66A, 66B is that the reinforcing fibers 42 are bonded over a sufficient length to withstand forces. The excess matrix 40 fills and impregnates the shorter fibers 42 across the width away from the center, as if there were no junction. Surprisingly, micrographic sections of the junction 62 show no singularity.

[0122] Each front zone 66A, 66B projects from the respective rear zone 72A, 72B. It is delimited by two lateral edges 68, 70 each having at least one point, in particular at least one segment, placed away from the respective extension of each lateral edge 74, 76 of the rear zone 72A, 72B.

[0123] The front zone 66A, 66B thus has at its free end a width strictly less than that of the rear zone 72A, 72B. Advantageously, the width of the front zone 66A, 66B decreases continuously from the rear zone 72A, 72B towards the free end.

[0124] Advantageously, each front zone 66A, 66B comprises an inclined edge 68 and an additional inclined edge 70 which extend on either side of the longitudinal axis F-F'. In this example, the inclined edge 68 and the additional inclined edge 70 intersect on the strip portion 60A, 60B and together define an end point 78 of the strip portion 60A, 60B. The front zone 66A, 66B thus has a triangular shape having the end point 68 as its apex.

[0125] The angle of inclination 0 of the inclined edge 68 relative to the longitudinal axis F-F' is for example between 20° and 80°, in particular between 30° and 60°, even more in particular between 35° and 55°.

[0126] The additional inclined edge 70 advantageously has an inclination angle -0 opposite to the inclination angle 0 of the inclined edge 68.

[0127] The angle of inclination -0 of the additional inclined edge 70 is for example between -20° and -80°, in particular between -30° and -60°, even more in particular between -35° and -55°.

[0128] The length H of the front zone 66A, 66B, taken along the axis F-F' between the end point 78 and the projection onto the axis F-F' of the points of intersection of the inclined edges 68, 70 with the respective lateral edges 74, 76, is equal to the length of the rear zone 72A, 72B intended to receive the front zone 66B, 66A of the other strip portion 60B, 60A.

[0129] The method for manufacturing the strip 2 is implemented in a manufacturing installation shown schematically in [Fig.3].

[0130] The installation advantageously comprises a station 82 for supplying or manufacturing strip parts 60A, 60B, comprising if necessary an apparatus 84 for cutting each inclined edge 68, 70. The installation comprises a welding station 86 intended to weld together the end regions 64A, 64B thus formed.

[0131] The supply or manufacturing station 82 is suitable for supplying or manufacturing strip parts 60A, 60B made of composite material having a matrix 40 and fibers 42 as described above.

[0132] The maximum length of the strip portions 60A, 60B formed in the station 82 is for example less than 5000 m. This length is for example greater than 350 m and in particular between 500 m and 1500 m.

[0133] In one embodiment, the outline of the strip portions 60A, 60B initially supplied or manufactured by the station 82 is rectangular. The cutting apparatus 84 is then capable of producing by cutting each inclined edge 68, 70 in the region end 64A, 64B of each strip portion 60A, 60B. The cutting is carried out with a blade and / or by laser cutting.

[0134] In the example illustrated by [Fig.7], the cutting apparatus 84 comprises a base 200 defining a groove 202 for receiving a portion of strip, a cutting wedge 204, mounted to move relative to the base 200 between a loading / unloading position for a portion of strip 60A, 60B and a cutting position for the portion of strip 60A, 60B. The cutting apparatus 84 advantageously comprises guides 206 for moving the cutting wedge 204.

[0135] The base 200 has an end 208 with a contour cutout identical to the contour of the front zone 66A, 66B of each end region 64A, 64B.

[0136] The cutting wedge 204 also has a cutting end 210 with a contour identical to the contour of the front zone 66A, 66B of each end region 64A, 64B. The cutting end 210 is provided with at least one blade 211 projecting towards the base 200 along the contour of the cutting end 210.

[0137] The movement guides 206 are for example formed by parallel rods 212 projecting from the base 200. Each rod 212 is received in a complementary through passage 214 provided through the cutting wedge 204.

[0138] To carry out the cutting, a portion of strip 60A, 60B initially supplied or manufactured by station 82 with a rectangular outline is introduced into the groove 202 of the base 200, the cutting wedge 204 occupying its loading / unloading position.

[0139] The cutting wedge 204 is then passed into its cutting position in the vicinity of the base 200. The blades 211 located at the cutting end 210 cut the lateral edges 68, 70 of the front zone 66A, 66B, along the contour of the cutting end 208 of the base 200.

[0140] Alternatively, the strip portions 60A, 60B supplied or manufactured by the station 82 have the or each inclined edge 68, 70 in the end region 64A, 64B of each strip portion 60A, 60B. The installation is then without a cutting station 84.

[0141] As illustrated by [Fig.3], the welding station 86 comprises a metal support 88, intended to be heated preferably by induction, and advantageously, at least one induction coil 90 intended to be placed opposite a heating region 91 of the metal support 88, and at least one movable wedge 92 for applying pressure.

[0142] Alternatively, the welding station 86 comprises a non-inductive heating device.

[0143] The wedge 92 is movable relative to the metal support 88 between a retracted position for placing the end regions 64A, 64B of the strip parts 60A, 60B and a position for applying pressure to the end regions 64A, 64B of the strip parts 60A, 60B.

[0144] The metal support 88 has an upper surface 94 intended to receive each strip portion 60A, 60B in support and to place the end regions 64A, 64B in superposition on one another in the heating region 91 opposite the induction coil 90.

[0145] The metal support 88 is for example made of aluminum or tool steel.

[0146] The induction coil 90 is capable of being powered by a variable electric current from a source (not shown), to generate in the heating region 91 of the metal support 88, located opposite the coil 90, induced currents capable of heating the metal support 88 by the Joule effect.

[0147] The thickness of the metal support 88 up to the surface 94, taken in the heating region 91 opposite the induction coil 90 is for example less than 5 mm, and is notably between 1 mm and 3 mm.

[0148] The currents induced by the coil 90 in the heating region 91 are capable of increasing the temperature of the metal support 88 in the heating region 91 to a temperature higher than the melting temperature of the polymer, i.e. 340°C and in particular to a temperature between 345°C and 360°C for a PEEK matrix. Heating by induced currents preferably makes it possible to obtain a temperature rise gradient greater than 15°C / s, in particular between 17°C / s and 25°C / s.

[0149] This temperature is sufficient to cause at least partial melting of the polymer matrix 40 of the end regions 64A, 64B.

[0150] The wedge 92 internally defines an imprint 96 of parallelepipedal volume and of width corresponding to the width of the strip 2 taken between the parallel lateral edges 74, 76.

[0151] The wedge 92 is movable relative to the upper surface 94 of the metal support 88 between the retracted position and the position applied to the metal support 88.

[0152] When applied to the surface 94, the shim 92 applies pressure to the superimposed end regions 64A, 64B, ensuring mixing between the polymer matrices 40 and the reinforcing fibers 42 of each of the end regions 64A, 64B to produce the junction 62 after cooling.

[0153] A method of manufacturing the composite strip 2 in the installation will now be described.

[0154] Initially, the strip parts 60A, 60B are manufactured separately from each other and / or are supplied in the supply and / or manufacturing station 82.

[0155] In the case where the strip portions 60A, 60B initially have a rectangular outline, the end regions 64A, 64B are brought into the cutting apparatus 84 to be cut there and form the inclined edge 68 and the additional inclined edge 70, with the tilt angle 0 or -0 defined above.

[0156] This being done, the strip portions 60A, 60B are arranged on the upper surface 94 of the metal support 88.

[0157] In the heating region 91, the front zone 66A of an end region 64A of a first strip portion 60A is arranged in contact with the rear zone 72B of an end region 64B of a second strip portion 60B, above the latter.

[0158] As a result, the front area 66B of the end region 64B of the second strip portion 60B is disposed below the rear area 72A of the end region 64A of the first strip portion 60A.

[0159] This being done, the welding station 86 is activated to form the junction 62. For this purpose, an alternating current is supplied to the induction coil 90, which generates induced currents in the metal support 88, and heating of the upper surface 94 by Joule effect.

[0160] This heating causes at least partial melting of the polymer matrix 40 of the end regions 64A, 64B.

[0161] The movable wedge 92 is then moved from its retracted position to its position applied to the end regions 64A, 64B of the strip portions 60A, 60B. The polymer matrices 40 of the end regions 64A, 64B mix and form the junction 62.

[0162] Then, with the power supply to the coil 90 cut off, the polymer matrix 40 in the region of the junction 62 cools and solidifies to form the junction 62.

[0163] It should be noted that the trace of the inclined edges 68, 70 of each end region 64A, 64B advantageously remains visible on the outer surface of the strip 2, even after welding.

[0164] The strip 2 is then possibly wound onto a reel, so that it can be used in an installation 98 for manufacturing the flexible pipe 10, shown schematically in [Fig.4].

[0165] The installation 98 comprises a station 100 for supplying the sheath 20, possibly a pre-compaction station 102, a station 104 for forming the tubular structure 4 and possibly a post-compaction station 106.

[0166] The installation 98 advantageously comprises a station 108 for winding the armor layers 24, 25 and a station 110 for forming the outer sheath 30.

[0167] The supply station 100 of the sheath 20 is suitable for manufacturing and / or unwinding the sheath 20 along a longitudinal axis A-A', with a view to its introduction into the successive stations 102, 104, 106. The sheath 20 thus defines a cylindrical external surface 112 (see in particular [Fig.5]) on which the tubular structure 4 is formed.

[0168] The forming station 104 is illustrated schematically in [Fig. 5]. It comprises a frame 120 delimiting a central passage 122 for circulation of the sheath 20 along a central axis A-A', an apparatus 124 for parallel winding of a plurality of strips 2 on the external surface 112 defined here by the sheath 20, and at least one device 126 for heating the strips 2.

[0169] The training station 104 further comprises a compacting device 128.

[0170] The frame 120 here comprises a fixed structure fixed to the ground, at least one element of rotary support formed by a mobile cage 132 mounted to rotate on a fixed structure around the central axis A-A', and a mechanism 134 for driving the mobile cage 132 in rotation relative to the fixed structure.

[0171] The movable cage 132 comprises a drum 136 rotating around the central axis A-A' and a support 138 carried by the drum 136 away from the central axis A-A'.

[0172] The central passage 122 passes through the drum 136.

[0173] The winding apparatus 124 is mounted on the support 138 of the movable cage 132 to be driven in rotation jointly with the movable cage 132 around the axis A-A'.

[0174] The winding apparatus 124 comprises a plurality of unwinders 142, and elements (not shown) for guiding the strips 2 coming from each unwinder 142 to guide them towards the external surface 112 while keeping them parallel.

[0175] Each unwinder 142 is capable of unwinding at least one strip 2 intended to form a reinforcing layer.

[0176] Each unwinder 142 comprises at least one reel on which at least one strip 2 is wound.

[0177] The guide elements comprise guides for aligning the strips 2 parallel to each other along an axis inclined relative to the central axis A-A' by an angle equal to the helix angle y, to allow the strips 2 coming from each unwinder 142 to be wound in a helix around the external surface 112 during the rotation of the movable cage 132 around the axis A-A'.

[0178] The heating apparatus 126 is also carried by the support 138 of the mobile cage 132. It is placed opposite the external surface 112, at the region of application of the strips 2 on the external surface 112. It comprises for example a laser, a lamp, in particular a xenon lamp, an infrared lamp, a pulsed light device, an ultrasonic welding device and / or a hot air blowing device.

[0179] The heating apparatus 126 is capable of softening, advantageously of melting, the thermoplastic matrix 40 of the strip 2 to allow its complementary application on the external surface 112.

[0180] In this example, the compacting device 128 comprises a frame common with the frame 120 of the forming station 104. It comprises at least one train of rollers 150 carried by the movable cage 132 to be driven jointly in rotation with the movable cage 132 around the central axis A-A' relative to the external surface 112. The compacting device 128 further comprises an approach mechanism 152, suitable for moving each roller train 150 towards the central axis A-A'.

[0181] The compacting device 128 is for example of the type described in the Applicant's patent application FR3079162.

[0182] A method of manufacturing a tubular structure 4 according to the invention in the installation 98 will now be described, in the example of the production of a flexible pipe 10.

[0183] Initially, the sheath 20 is manufactured and / or supplied in the supply station 100. It is brought to the station 104 for forming the structure 4, and is moved in translation through the station 104 for forming the structure 4 along the axis A-A', by a translation drive device.

[0184] Advantageously, before the station 104, the sheath 20 passes into the pre-compaction station 102. The sheath 20 first passes into a heating device 126, to bring its external surface 112 to a temperature greater than 100°C, and in particular between 100°C and 350°C.

[0185] Roller trains 150 are driven in rotation around the sheath 20. The rollers are applied to the external surface 112 to make it as cylindrical as possible.

[0186] Then, the sheath 20 is introduced into the central passage 122 of the training station 104.

[0187] In this station 104, a plurality of reinforcing layers are formed from the bands 2.

[0188] For each reinforcement layer, a plurality of strips 2 are unwound in parallel from the unwinders 142 of the winding apparatus 124. The guide elements keep the strips 2 parallel to each other, with controlled play.

[0189] The parallel strips 2 pass in front of the heating apparatus 126, where they are advantageously heated to a temperature between 150°C and 450°C, said temperature depending on the nature of the thermoplastic polymer constituting the matrix 40 of the strips 2.

[0190] When the matrix 40 of the strips 2 is made of PEEK (melting point of the order of 350°C), the heating temperature of the strips 2 by the heating apparatus 126 is advantageously between 350°C and 450°C, preferably between 380°C and 420°C. When the matrix 40 of the strips 2 is made of PVDF (melting point of the order of 180°C), the heating temperature of the strips 2 by the heating apparatus 126 is advantageously between 180°C and 280°C, preferably between 200°C and 250°C. This advantageously leads to at least partial melting of the matrix 40.

[0191] The mobile cage 132 being driven in rotation around the axis A-A', and the sheath 20 moving in translation along the axis A-A', the strips 2 are wound in a helix around the external surface 112 defined by the sheath 20 or defined by a layer formed around the sheath 20, with a helix angle equal to y.

[0192] Immediately after their winding, the roller train 150 driven in rotation jointly with the movable cage 132 is applied to the bands 2.

[0193] Then, the tubular structure 4 thus formed passes into the post-compaction station 106. The external surface 112 of the tubular structure 4 is then softened as it passes through a heating apparatus, then is compacted again by rotating roller trains 150. The rollers of the roller trains 150 roll along a helical trajectory along the respective strips 2, ensuring minimal disorganization of the reinforcing fibers 42.

[0194] Advantageously, the operations of pre-compaction (station 102), formation of the tubular structure (station 104) and post-compaction (station 106) are repeated (loop 101 in [Fig.2]) to form other reinforcement layers with other strips 2, as described previously.

[0195] The tubular structure 4 is thus manufactured layer by layer by adding, at each passage through the station 104, a new outer layer of thickness substantially equal to that of a strip 2. These operations can be repeated several dozen times, in particular when the strip(s) 2 have a thickness significantly less than the final thickness of the wall of the tubular structure 4.

[0196] In addition, the characteristics of the strips 2 and / or the laying and / or compaction parameters can be modified each time a new layer is added. For example, it is possible to modify the helix angle of the strips 2, in particular to cross the fibers of two superimposed layers.

[0197] Then, the tubular structure 4 passes into the winding station 108, to allow the armor plies 24, 25 to be put in place.

[0198] The armor elements 50 of the tensile armor plies 24, 25 are wound around the tubular reinforcement structure 4, in a manner not connected to the tubular reinforcement structure 4. Advantageously, an anti-wear layer 26 is interposed between the tubular reinforcement structure 4 and the first tensile armor ply 24, and between each pair of tensile armor plies 24, 25.

[0199] Then, advantageously, a reinforcing tape 28 is wound around the outermost tensile armor ply 25.

[0200] Next, in the outer sheath forming station 110, the outer sheath 30 is formed around the armor plies 24, 25.

[0201] The composite strips 2 manufactured by the method according to the invention are therefore particularly suitable for use in the formation of a tubular structure 4 of a flexible pipe 10 in a station 104 comprising a heating apparatus 126, for example a laser.

[0202] For the manufacture of the strip 2, the use of a welding station 86 operating by induction, associated with the use of disjointed strip portions 60A, 60B having an end region 64A, 64B having at least one inclined edge 68, 70 makes it possible to produce a welded joint 62 between strip portions 60A, 60B which is robust, while having a low stiffness, and a tension resistance adequate to be unwound from each unwinder 142 and wound on the external surface 112.

[0203] The presence of the junctions 62 produced by welding between the parts of the strips 60A, 60B using induction heating avoids locally producing high temperatures when passing through the station 104, in particular when this station comprises a laser heating device 126. No flash or combustion effect is observed at the junction 62.

[0204] The junction 62 between the strip parts 60A, 60B remains simple and quick to produce, and does not produce holes, debris, or areas with detachment.

[0205] The end regions 64A, 64B of the strip portions 60A, 60B can be easily prepared by simple cutting, with a view to their welding.

[0206] The application of heat and pressure to weld the end regions 64A, 64B together is performed without applying a film to the surface of each end region 64A, 64B.

[0207] It is thus possible to produce a continuous strip of great length, directly usable for the manufacture of tubular structures 4, in particular within a flexible pipe 10 intended for great depths.

[0208] In a variant (not shown), at least one end region 64A, 64B has a male front zone 66A, 66B which is not necessarily triangular.

Claims

Claims

1. A method of manufacturing a strip (2) of composite material, intended to form a tubular structure (4), the method comprising the following steps: - end-to-end application of end regions (64A, 64B) of disjointed strip portions (60A, 60B), each strip portion (60A, 60B) being formed of a polymer matrix (40) and fibers (42) or a film embedded in the matrix (40), - application of heat and pressure to produce a junction (62) by welding between the end regions (64A, 64B), characterized in that at least one end region (64A, 64B) has a rear zone (72A, 72B) in which the lateral edges (74, 76) of the strip portion (60A, 60B) are parallel to each other, and a front zone (66A, 66B) in which the lateral edges (74, 76) of the strip portion (60A, 60B) are parallel to each other, 66B) projecting from the rear area (72A, 72B), the front area (66A, 66B) being delimited by two lateral edges (68, 70) each having at least one point, in particular at least one segment,placed away from a respective extension of each lateral edge (74, 76) of the rear zone (72A, 72B), between the respective extensions of each lateral edge (74, 76) of the rear zone (72A, 72B), the front zone (66A) of an end region (60A) of a first strip portion (60A) being located opposite an end region (64B) of a second strip portion (60B) during the end-to-end application of the end regions (64A, 64B), and the application of heat and pressure comprises the induction heating of a heating region (91) of a metal support (88) on which the end regions (64A, 64B) of the strip portions (60A, 60B) are arranged.,

2. A method according to claim 1, wherein arranging an induction coil (90) opposite the heating region (91) of the metal support (88), and circulating a variable electric current in the induction coil (90) to generate heat by Joule effect by currents induced in the heating region (91).

3. A method according to claim 2, comprising moving a pressure applying shim (92) over the heating region (91), and applying pressure to the end regions (64A, 64B) of the strip portions (60A, 60B) between the metal support (88) and the shim (92).

4. Method according to any one of the preceding claims, wherein, when applying the end regions (64A, 64B) end to end, at least one side edge (68, 70) of the front area (66A; 66B) is an inclined side edge, the angle of inclination (0) of the inclined side edge (68, 70) relative to the longitudinal axis (F-F') of the strip portion (60A, 60B) in the end region (64A, 64B) is between 20° and 80°, in particular between 30° and 60°, even more in particular between 35° and 55°.

5. A method according to any preceding claim, wherein, when applying the end regions (64A, 64B) end to end, the front area (66A; 66B) of the end region (64A, 64B) comprises an inclined side edge (68) and an additional inclined side edge (70), the additional inclined side edge (70) being inclined relative to the longitudinal axis (F-F') of the strip portion (60A, 60B) by an angle of inclination (-0) opposite to the angle of inclination (0) of the inclined side edge (68, 70) relative to the longitudinal axis (F-F') of the strip portion (60A, 60B).

6. The method of claim 5, wherein the additional inclined side edge (70) intersects with the inclined side edge (70) at an end point (78) of the strip portion (60A, 60B).

7. A method according to any one of the preceding claims, wherein each end region (64A, 64B) has a rear area (72A, 72B) in which the lateral edges (74, 76) of the strip portion (60A, 60B) are parallel to each other, and a front area (66A, 66B) projecting from the rear area (72A, 72B), the front area (66A, 66B) being delimited by two lateral edges (68, 70) each having at least one point, in particular at least one segment, placed away from a respective extension of each lateral edge (74, 76) of the rear area (72A, 72B), between the respective extensions of each lateral edge (74, 76) of the rear area (72A, 72B), the front area (66A) of an end region (60A) of a first strip portion (60A) being located opposite the rear area (72B) of an end region (64B) of a second strip portion (60B) when the end regions (64A, 64B) are applied end to end.

8. A method according to any preceding claim, wherein the application of heat and pressure to weld the end regions (64A, 64B) together is carried out without application of material, in particular without application of a film to the surface of each end region (64A, 64B).

9. A method according to any one of the preceding claims, wherein, when applying the end regions (64A, 64B) end to end, the overlap between the end region (64A) of a first strip portion (60A) and the end region (64B) of a second strip portion (60B), measured along the longitudinal axis (F-F') of each end region (64A, 64B), is greater than 10 mm, and is in particular between 15 mm and 30 mm.

10. A method according to any one of the preceding claims, wherein the matrix (40) is made of a polymer selected from PEK (polyetherketone), PEEK (polyetheretherketone), PEEKK (polyetheretherketoneketone), PEKK (polyetherketoneketone), PEKEKK (polyetherketoneetherketoneketone), P AI (polyamide-imide), PEI (polyether-imide), PSU (polysulfone), PPSU (polyphenylsulfone), PES (polyethersulfone), PAS (polyarylsulfone), PPE (polyphenylene ether), PPS (polyphenylene sulfide), LCP (liquid crystal polymers), PPA (polyphthalamide), their copolymers and / or their mixtures, and wherein the fibers (42) are selected from carbon fibers, glass fibers, aramid fibers, and / or basalt fibers, the fibers advantageously forming a mat, or wherein the film is a polyketone yarn, in particular unfilled PEEK (polyetheretherketone).

11. Use of at least one strip of composite material (2) produced by the manufacturing method according to any one of the preceding claims to form, advantageously by winding and heating, a tubular structure (4), in particular a tubular structure (4) of a flexible pipe (10).

12. Installation for manufacturing a strip (2) of composite material intended to form a tubular structure (4), the installation comprising: a supply or manufacturing station (82) suitable for supplying disjointed strip parts (60A, 60B), each strip part (60A, 60B) being formed from a polymer matrix (40) and fibers (42) embedded in the matrix (40), a welding station (86) comprising a support (88) having a heating region (91) intended for the end-to-end application of the end regions (64A, 64B), and a device for applying heat and pressure to produce a junction (62) by welding between the regions end region (64A, 64B), the supply and manufacturing station (82) comprising a cutting apparatus (84) configured to form at least one end region (64A, 64B) having a rear area (72A, 72B) in which the lateral edges (74, 76) of the strip portion (60A, 60B) are parallel to each other, and a front area (66A, 66B) projecting from the rear area (72A, 72B), the front area (66A, 66B) being delimited by two lateral edges (68, 70) each having at least one point, in particular at least one segment, placed away from a respective extension of each lateral edge (74, 76) of the rear area (72A, 72B), between the respective extensions of each lateral edge (74, 76) of the area rear (72A, 72B), wherein the heat and pressure application device comprises a metal support (88) having a heating region on which the end regions (64A, 64B) of the strip portions (60A, 60B) are intended to be arranged,the heat and pressure application device being suitable for inductively heating the heating region (91) of the metal support (88).,

13. Installation according to claim 12, in which the device for applying heat and pressure comprises an induction coil (90) placed opposite the heating region (91) of the metal support (88), and a variable electric current source suitable for supplying the induction coil (90) to generate heat by Joule effect by currents induced in the heating region (91).

14. Installation according to claim 13, in which the heat and pressure application device comprises a movable pressure application wedge (92) on the heating region (91), suitable for applying pressure to the end regions (64A, 64B) of the strip portions (60A, 60B) between the metal support (88) and the wedge (92).

15. Installation according to any one of claims 12 to 14, in which the cutting apparatus (84) comprises a base (200) defining a groove (202) for receiving a portion of strip (60A, 60B), a cutting wedge (204), mounted movably relative to the base (200) between a position for loading / unloading a portion of strip (60A, 60B) and a position for cutting the portion of strip (60A, 60B), the cutting apparatus (84) advantageously comprising guides (206) for moving the cutting wedge (204).

Images