Method for manufacturing an axisymmetric fibre preform using a reusable take-up strip

Abstract

The invention relates to a method for manufacturing an axisymmetric fibre preform (280), the method comprising: - three-dimensional weaving of a fibre texture (200) in the form of a strip; - winding the fibre texture (200) onto a take-up spool (340); - winding the fibre texture (200) under tension onto an injection mould (430), wherein the fibre texture is unwound from the take-up spool (340). The method further comprises: - before the winding under tension of the fibre texture (200) onto the take-up spool (340), making a connection (50) between the fibre texture and a take-up strip (20) attached to the take-up spool (340); - after the winding of the fibre texture (200) onto the injection mould (430), breaking the connection (50). The connection (50) between the end of the fibre texture and the first end of the take-up strip exhibits flexibility in a transverse direction (DT).

Description

[0001] Description

[0002] Title of the invention: Method for manufacturing a revolution-shaped fiber preform using a reusable take-up strip

[0003] Technical Field

[0004] The present invention relates to the production of fibrous revolution preforms intended to constitute the fibrous reinforcement of revolution parts made of composite material.

[0005] Prior art

[0006] The field of application of the invention is more particularly the production of revolution parts in structural composite material, that is to say structural parts with fiber reinforcement densified by a matrix. Composite materials make it possible to produce parts having a lower overall mass than these same parts when they are made of metallic material.

[0007] In the case of a part of revolution shape, such as for example an aircraft engine casing, the fiber preform intended to form the reinforcement of the part is produced from a fiber texture wound on a support tool. The manufacture of a fan casing in organic matrix composite material is described in particular in document US 8,322,971.

[0008] More specifically, as illustrated in Figure 1, a strip-shaped fibrous texture 10 is woven in a single piece by three-dimensional (3D) weaving between a plurality of layers of warp yarns. The 3D weaving of the fibrous texture 10 is carried out in a Jacquard type loom 20, the weaving consisting of inserting weft yarns 12, creating a pattern, between warp yarns 11. Upon exiting the loom 20, the fibrous texture 10 is wound under tension onto a support tool or storage mandrel 30 having an external surface 30a on which the fibrous texture 10 is wound.

[0009] A fiber preform is then produced by winding the fiber texture 10 under tension onto an injection mold. As illustrated in FIG. 2, intermediate conveyor rollers 40 and 50 are used to homogenize the tension across the width of the fiber texture 10 during its winding under tension onto an injection mold 60, the texture 10 being unwound from the storage mandrel 30. The injection mold 60 is a mandrel onto the outer surface of which the fiber texture 10 is wound under tension, said outer surface having a shape corresponding to the composite material part to be produced.

[0010] At the end of the winding, that is to say after the completion of several turns of the fibrous texture 10 on the injection mold 60 so as to form a fibrous preform 80, the fibrous texture is cut by a knife 70 as illustrated in FIG. 3.

[0011] This winding solution has drawbacks. Indeed, it requires providing an excess length in the fibrous texture because it must be kept permanently under tension until the end of its winding on the injection mold. As shown in Figure 3, an excess length 15 of the fibrous texture 10 is present between the storage mandrel 30 and the injection mold 60 at the end of the winding in order to allow the fibrous texture 10 to be kept under tension. The excess length 15 is woven in the continuity of the texture 10 used to produce the preform 80. The start of the weaving of the fibrous texture 10 corresponding to the end of the winding, the excess length 15 is woven at the start of the fibrous texture 10 and fixed on the storage mandrel 30.

[0012] Since the excess length is linked to each fiber texture, it is eliminated as soon as the preform 80 is cut. The excess length 15 is then lost because it cannot be reused. This loss of material increases the manufacturing cost of the preform and the resulting composite material part.

[0013] Statement of the invention

[0014] It is therefore desirable to have a solution for producing fiber preforms by winding which does not have the aforementioned drawbacks.

[0015] For this purpose, according to the invention, a method is proposed for manufacturing a fiber preform of revolution intended for the manufacture of parts of revolution in composite material, the method comprising: - three-dimensional weaving between a plurality of layers of warp threads linked together by weft threads of a fiber texture in the form of a strip in a loom, the fiber texture extending in length in a longitudinal direction and in width in a transverse direction,

[0016] - winding the fibrous texture coming out of the loom onto a storage mandrel,

[0017] - winding under tension the fibrous texture onto an injection mold, the fibrous texture being unwound from the storage mandrel, characterized in that the method further comprises:

[0018] - before winding the fibrous texture under tension onto the storage mandrel, making a connection between one end of the fibrous texture and a first end of a take-up strip, a second end of the take-up strip being fixed to the storage mandrel,

[0019] - after winding the fibrous texture onto the injection mold, separating the connection between the end of the fibrous texture and the first end of the take-up strip, and in that the connection between the end of the fibrous texture and the first end of the take-up strip has flexibility in the transverse direction.

[0020] Thanks to the use of a take-up strip, the excess length of the fiber texture, usually used to maintain tension between the storage mandrel and the injection mold at the end of winding and sacrificed during cutting of the preform, is no longer necessary, this being replaced by the take-up strip which can be reused for the formation of new fiber preforms.

[0021] Furthermore, the connection made between the fibrous texture and the take-up strip, having flexibility in the transverse direction, adapts to the movements and conformation of the fibrous texture during its winding and generates almost no additional tension or stress in the formed preform.

[0022] According to a particular characteristic of the method of the invention, the connection between the end of the fibrous texture and the first end of the take-up strip is achieved by arranging a spiral fastener around superimposed portions of the end of the fibrous texture and the first end of the take-up strip and around at least two connecting rods placed respectively on said portions and extending in the transverse direction, each connecting rod having flexibility in the transverse direction.

[0023] According to another particular characteristic of the method of the invention, the connection between the end of the fibrous texture and the first end of the take-up strip is made by a zipper comprising first and second ribbons provided, along one of their edges, with attachment means and a slider which slides along the edges of the ribbons to lock or unlock the attachment means, the first ribbon being fixed to the first end of the take-up strip and the second ribbon being fixed to the end of the fibrous texture.

[0024] According to another particular characteristic of the method of the invention, the connection between the end of the fibrous texture and the first end of the take-up strip is made by sewing superimposed portions of the end of the fibrous texture and the first end of the take-up strip.

[0025] According to another particular characteristic of the method of the invention, the connection between the end of the fibrous texture and the first end of the take-up strip is made by sewing a folded portion of the end of the fibrous texture with a folded portion of the first end of the take-up strip.

[0026] According to another particular characteristic of the method of the invention, the length of the take-up strip is at least equal to a conveying distance between the storage mandrel and the injection mold.

[0027] According to another particular characteristic of the method of the invention, the connection made between the end of the fibrous texture and the first end of the take-up strip has an excess thickness corresponding to at most 150% of the thickness of the fibrous texture.

[0028] According to another particular characteristic of the method of the invention, the tension applied to the fibrous texture during its winding onto the injection mold is at least 2 N per thread or warp strand of the fibrous texture.

[0029] According to another particular characteristic of the method of the invention, the fibrous texture is woven with yarns made of carbon fibers, glass fibers or a mixture of carbon fibers and glass fibers. Brief description of the drawings

[0030] [Fig. 1] Figure 1 is a schematic view showing the weaving and storage on a support tool of a strip-shaped fibrous texture according to the prior art,

[0031] [Fig. 2] Figure 2 is a schematic side view showing the formation of a revolution fiber preform by tension winding of the fiber texture of Figure 1,

[0032] [Fig. 3] Figure 3 is a schematic side view showing the completion of the formation of a revolution fiber preform by tension winding of the fiber texture of Figure 1,

[0033] [Fig. 4] Figure 4 is a schematic perspective view of a Jacquard type loom,

[0034] [Fig. 5] Figure 5 is a schematic side view showing the weaving and storage of a fibrous texture in accordance with one embodiment of the invention,

[0035] [Fig. 6] Figure 6 is a schematic side view showing the formation of a revolution fiber preform by tension winding a fiber texture previously wound onto a storage mandrel of Figure 5,

[0036] [Fig. 7] Figure 7 is a schematic side view showing the completion of the formation of a revolution fiber preform by tension winding of a fiber texture previously wound onto a storage mandrel of Figure 5,

[0037] [Fig. 8] Figure 8 is a schematic perspective view of a fastening system for providing a connection between a take-up strip and a fibrous texture in accordance with one embodiment of the invention,

[0038] [Fig. 9] Figure 9 is a schematic perspective view of a fastening system for providing a connection between a take-up strip and a fibrous texture in accordance with another embodiment of the invention,

[0039] [Fig. 10] Figure 10 is a schematic perspective view of a fastening system for providing a connection between a take-up strip and a fibrous texture in accordance with another embodiment of the invention, [Fig. 11] Figure 11 is a schematic perspective view of a fastening system for providing a connection between a take-up strip and a fibrous texture in accordance with another embodiment of the invention.

[0040] Description of the embodiments

[0041] The invention applies generally to the production of revolution parts made of composite material such as aircraft engine casings, for example fan casings, these parts being obtained by producing revolution fiber preforms by winding and densifying these preforms with a matrix. These parts, such as aircraft engine casings, are of large dimensions, for various ranges of these engines, such as aircraft propulsion turbomachines, these casings being able to have a diameter of the order of one meter up to three and a half meters.

[0042] In accordance with the invention and as described in detail below, the present invention proposes to use a reusable take-up strip making it possible to wind a fibrous texture under tension during its storage and during its shaping without or with very little loss of material.

[0043] The method for producing a fibrous texture according to the invention begins with the formation of a fibrous texture in the form of a strip which is then wound onto a support tool. The fibrous texture is here intended to form a fibrous preform of an aircraft engine casing.

[0044] The fibrous texture is obtained by three-dimensional (3D) weaving carried out in a known manner using a jacquard-type loom on which a bundle of warp threads or strands has been arranged in a plurality of layers, the warp threads being linked by weft threads. In the example described here, the 3D weave is an "interlock" weave. By "interlock" weave, we mean here a weave weave in which each layer of weft threads links several layers of warp threads with all the threads of the same weft column having the same movement in the plane of the weave. Other known types of multi-layer weaving may be used, such as those described in WO 2006 / 136755. The fibrous texture according to the invention is woven from threads such as, in particular, but not exclusively, carbon fiber threads, glass fiber threads or a mixture of carbon fibers and glass fibers.

[0045] Figure 4 illustrates a loom 100 equipped with a Jacquard mechanism 101 supported by a superstructure not shown in Figure 4. The loom 100 also comprises a harness 110 consisting of a weaving board 111 and control threads or heddles 113, each heddle 113 being connected at one end to a control hook 1010 of the Jacquard mechanism 101 and at the other end to one of the return springs 102 fixed to the frame 103 of the loom 100. Each heddle 113 comprises an eyelet 114 crossed by a warp thread 201. The heddles 113 and their associated eyelet 114 extend in a zone in which the heddles 113 and the eyelets 114 are animated by a substantially vertical oscillating movement represented by the double arrow F. The heddles 113 are subjected to traction forces respectively exerted by the control hooks 1010 and by the return springs 102. The heddles 113 make it possible to lift certain warp threads

[0046] 201 following a defined weaving program. By lifting certain warp threads 201, the heddles 113 thus create a shed allowing the introduction of weft threads

[0047] 202 for 3D or multi-layer weaving of a fibrous texture 200 in the form of a strip or ribbon. The warp threads 201 are organized into a plurality of layers of warp threads C1 to Cn. A comb 120 present upstream of the shed packs each introduced weft thread by moving from upstream to downstream to a position corresponding to the closing of the shed. The warp threads 201 are brought from bobbins arranged on a creel (not shown in FIG. 1) upstream of the Jacquard mechanism 101 of the loom 100.

[0048] Figure 5 shows an installation 300 for manufacturing and storing a fibrous texture 200 according to one embodiment of the invention. The installation 300 comprises the weaving loom 100 described above, three transport rollers 310, 320 and 330 present downstream of the weaving loom 100 and a storage mandrel 340. The fibrous texture 200 is obtained at the outlet of the weaving loom 100, that is to say the zone from which the warp threads 201 are no longer woven with the weft threads 202. At the outlet of the weaving loom, the fibrous texture 200 extends lengthwise in a longitudinal direction D L , in width following a transverse direction D T and in thickness following a thickness direction D E .

[0049] The storage mandrel 340, also called the “take-up” mandrel, is rotated in the direction of rotation S 34o, the storage mandrel 340 being present downstream of the transport roller 330. The warp threads are drawn into the loom 100 by the storage mandrel on which the fibrous texture 200 is wound, the storage mandrel being able for example to be driven in rotation by an electric motor (not shown in FIG. 5) whose angular position is controlled in order to adjust the draw of the threads into the loom. The installation for the manufacture and storage of a fibrous texture can of course comprise a smaller or larger number of transport rollers.

[0050] According to the invention, a take-up strip 20 is used to connect the fibrous texture 200 to the storage mandrel 340. More precisely and as illustrated in FIG. 5, before the tensioned winding of the fibrous texture 200 onto the storage mandrel 340, a free end 210 of the fibrous texture 200 corresponding to the start of weaving of said texture is connected to a first end 21 of the take-up strip 20 by means of a connection 50. A second end 22 of the take-up strip 20 is fixed to the storage mandrel 340. The second end 22 of the take-up strip 20 is fixed to the storage mandrel 340 preferably with a fixing system which does not create excess thickness on the surface of the mandrel. For this purpose, the storage mandrel may have on its external surface a recess making it possible to house a device for fixing the second end 22 of the take-up strip 20 and to integrate the latter into the geometry of the mandrel without excess thickness.Those skilled in the art will easily envisage other embodiments of the device for fixing the end of the strip to the storage mandrel.

[0051] The take-up strip 20 preferably has a textile structure configured to apply a homogeneous tension to the fibrous texture when it is wound onto the storage mandrel and, consequently, a yarn take-up similar to that obtained when the fibrous texture is directly fixed to the storage mandrel. The take-up strip may, for example, have a three-dimensional weave similar to the weave of the fibrous texture. According to another example, the take-up strip may have a two-dimensional (2D) weave whose weave is defined to have a profile and deformation behavior similar to that of the fibrous texture.Similarly, the take-up band may be woven with yarns having a material different from that of the yarns of the fibrous texture provided that the take-up band allows a homogeneous tension to be applied to the fibrous texture when it is wound onto the storage mandrel and, consequently, a yarn take-up similar to that obtained when the fibrous texture is directly fixed onto the storage mandrel.

[0052] The connection 50 between the end 210 of the fibrous texture 200 and the first end 21 of the take-up strip has both good resistance in the longitudinal direction D L in order to support the tensile forces resulting from the tension to be applied to the fibrous texture during its winding and flexibility or deformability in the transverse direction D Tin order to follow the movements of the fibrous texture in this direction. For example, the transport roller(s) used to convey the fibrous texture to the storage mandrel or to an injection mold as described below, the storage roller and / or the injection mold may have on their axial width, corresponding to the transverse direction D T of the fibrous texture, a variable radius so as to define an external surface having a relief profile corresponding to that which one wishes to give to the fibrous preform and to the final part of revolution. Thanks to its flexibility or deformability in the transverse direction D T , the link 50 will follow the relief profile as it passes over it without creating tension or stress in the fibrous texture.

[0053] Several attachment systems are now described for making the connection 50 between the fibrous texture 200 and the take-up strip 20 and which are capable of resisting tensile forces in the longitudinal direction D. L while exhibiting good flexibility or deformability in the transverse direction D T .

[0054] In Figure 8, the connection 50 between the end 210 of the fibrous texture 200 and the first end 21 of the take-up strip 20 is made with a fastening system 60 which comprises at least one spiral 61 arranged around superimposed portions 210a and 21a respectively of the end 210 of the fibrous texture 200 and the first end 21 of the take-up strip 20. The fastening system 60 further comprises at least two connecting rods 62 and 63 extending in the transverse direction D. Trespectively on the portion 210a and on the portion 21a. The connecting rods make it possible to reinforce the connection by the spiral 61 between the superimposed portions 210a and 21a respectively of the end 210 of the fibrous texture 200 and of the first end 21 of the take-up strip 20 which comprise so-called “floated” warp threads, i.e. non-woven warp threads with weft threads. Thanks to its structure and its arrangement, the spiral 61 has good resistance in the longitudinal direction D L while exhibiting good flexibility or deformability in the transverse direction D T . The connecting rods 62 and 63 have flexibility in the transverse direction. The spiral and the connecting rods may be made of polyester or polyethylene in particular.

[0055] In Figure 9, the connection 50 between the end 210 of the fibrous texture 200 and the first end 21 of the take-up strip 20 is made with a fastening system consisting of a zipper 70 comprising first and second ribbons 71 and 72 fixed respectively to the first end 21 of the take-up strip 20 and to the end 210 of the fibrous preform 200 for example by sewing, gluing or any other suitable fastening means. The first ribbon 71 is provided along its edge with first attachment means 73 while the second ribbon is provided along its edge with second attachment means 74, the first and second attachment means 73 and 74 are intended to cooperate with each other to close the connection between the take-up strip and the fibrous texture.For this purpose, the zipper 70 further comprises a slider 75 which slides along the edges of the ribbons 71 and 72 to lock or unlock the first and second hooking means 73 and 74, FIG. 9 showing the zipper 70 in its locking position. Thanks to its structure and arrangement, the zipper 70 has good strength in the longitudinal direction D. L while exhibiting good flexibility or deformability in the transverse direction D T .

[0056] In Figure 10, the connection 50 between the end 210 of the fibrous texture 200 and the first end 21 of the take-up strip 20 is made with a fastening system 80 formed by one or more seams 81 connecting together superimposed portions 210a and 21a respectively of the end 210 of the fibrous texture 200 and of the first end 21 of the take-up strip 20. Thanks to its structure and its arrangement, the fastening system 80 has good resistance in the longitudinal direction D L while exhibiting good flexibility or deformability in the transverse direction D T .

[0057] In Figure 11, the connection 50 between the end 210 of the fibrous texture 200 and the first end 21 of the take-up strip 20 is made with a fastening system 90 formed by one or more seams 91 connecting together a folded portion 210b of the end 210 of the fibrous texture 200 and a folded portion 21b of the first end 21 of the take-up strip 20. Thanks to its structure and its arrangement, the fastening system 90 has good resistance in the longitudinal direction D L while exhibiting good flexibility or deformability in the transverse direction D T .

[0058] After connecting the free end 210 of the fibrous texture 200 corresponding to the start of the weaving thereof to the first end 21 of the take-up strip 20 by means of the connection 50 (figure 5), the fibrous texture 200 is wound onto the storage mandrel 340 as the texture is woven. When the desired length of the fibrous texture 200 has been woven and wound onto the storage mandrel, the method of the invention continues by winding the fibrous texture under tension onto an injection mold so as to form a fibrous preform intended to form the fibrous reinforcement of a revolution part made of composite material.

[0059] Figures 6 and 7 show the production of a fiber preform 280 obtained from the fiber texture 200 stored on the storage mandrel 340. The fiber preform is produced by winding the fiber texture 200 under tension onto a tool or injection mold 430, intermediate conveyor rollers 410 and 420 being used to homogenize the tension across the width of the fiber texture during its winding under tension onto the injection mold 430, the fiber texture 200 being unwound from the storage mandrel 340 (Figure 6). The injection mold 430 comprises a mandrel 431 on the external surface of which the fiber texture is wound under tension, said external surface having a shape corresponding to the composite material part to be produced.Figure 6 shows the winding of the fibrous texture 200 onto the injection mold 430 at a stage where the fibrous texture 200 has been fully unwound from the storage mandrel and where the take-up strip 20 bonded to the fibrous texture 200 by the bond 50 begins to be unwound from the storage mandrel 340.

[0060] At the end of the winding as shown in Figure 7, that is to say after the completion of several turns of the fibrous texture on the injection mold 430 so as to form a fibrous preform 280, a pad 460 is positioned in order to hold the preform 280 in place and prevent it from unwinding during the separation of the connection 50 between the end 210 of the fibrous texture 200 and the first end 21 of the take-up strip 20. In the example described here, the separation of the ends 210 and 21 is carried out by cutting with a knife 470 at the connection 50. In the case of a removable or detachable connection, such as for example with the attachment system 60 previously described, it is not obligatory to carry out a cut. However, in the case of a fastening system using one or more seams, the portions of the ends of the fibrous texture and the call strip are preferably cut.

[0061] The cutting is carried out just in front of the connection 50, which allows for only a very small loss of material in the fibrous structure 200 used to produce the preform 280. Indeed, the excess length of the fibrous texture, usually necessary to maintain the tension between the support tooling and the molding tooling at the end of the winding and sacrificed during the cutting of the preform, is here replaced by the take-up strip 20. The take-up strip 20 can be advantageously reused for the formation of new fibrous textures and preforms.

[0062] The sacrificial overlengths to be provided on the take-up strip and the fibrous texture for separation at the level of connection 50 are negligible compared to the useful lengths of the take-up strip and the fibrous texture.

[0063] The length of the take-up strip 20 is at least equal to the conveying distance between the storage mandrel 340 and the injection mold 430 in order to allow complete winding under tension of the fibrous texture 200 before its separation from the take-up strip.

[0064] The connection made between the end 210 of the fibrous texture 200 and the first end 21 of the take-up strip 20 has an excess thickness preferably corresponding to at most 150% of the thickness of the fibrous texture so as not to disturb the winding during passage over the conveyor rollers and to minimize the impact on the profile of the preform.

[0065] The tension or tensile force applied to the fibrous texture during its winding is at least 2 Newtons per warp yarn or strand of the fibrous texture. The connection between the end of the fibrous texture and the first end of the take-up strip preferably has a mechanical strength enabling it to withstand at least three times the winding tension. The connection therefore has a strength capable of preferably withstanding a tensile force of at least 4 Newtons per millimeter of width of the connection.

[0066] The take-up band may be woven with the same yarns as the fibrous texture such as, but not limited to, carbon fiber yarns, glass fiber yarns, or a mixture of carbon fibers and glass fibers. In the case of a fibrous texture woven in whole or in part with carbon fiber yarns, the take-up band may be woven with glass fiber yarns which are less expensive than carbon fiber yarns.

[0067] Once the fiber preform has been formed, it is densified using a matrix. Densification of the fiber preform consists of filling the porosity of the preform, in all or part of its volume, with a material constituting the matrix. The matrix can be obtained in a manner known per se using the liquid process. The liquid process consists of impregnating the preform with a liquid composition containing an organic precursor of the matrix material. The organic precursor is usually in the form of a polymer, such as a resin, possibly diluted in a solvent. The injection mold on which the fiber preform is present is sealed, for example with sectors forming a counter-mold defining a housing having the shape of the final molded part, the sectors and the injection mold respectively having the external shape and the internal shape of the casing to be produced.Then, the liquid matrix precursor, for example a resin, is injected into the entire housing to impregnate the entire fibrous part of the preform.

[0068] The transformation of the precursor into an organic matrix, namely its polymerization, is carried out by heat treatment, generally by heating the mold, after removal of any solvent and crosslinking of the polymer, the preform being always maintained in the mold having a shape corresponding to that of the part to be produced. The organic matrix can be obtained in particular from epoxy resins, such as, for example, the high-performance epoxy resin sold, or from liquid precursors of carbon or ceramic matrices. Such densification of a fibrous preform of revolution is described in particular in document US2017 / 266893.

[0069] This produces a piece of revolution made of composite material comprising a fibrous reinforcement made up of the preform densified by a matrix.

Claims

Claims

1. Method for manufacturing a fiber preform of revolution (280) intended for the manufacture of a part of revolution in composite material, the method comprising: - three-dimensional weaving between a plurality of layers of warp threads (201) linked together by weft threads (202) of a fibrous texture (200) in the form of a strip in a loom (100), the fibrous texture extending lengthwise in a longitudinal direction (D L ) and in width following a transverse direction (D T ), - winding the fibrous texture (200) at the outlet of the loom onto a storage mandrel (340), - winding under tension the fibrous texture (200) onto an injection mold (430), the fibrous texture being unwound from the storage mandrel (340), characterized in that the method further comprises: - before winding under tension the fibrous texture (200) onto the storage mandrel (340), making a connection (50) between one end (210) of the fibrous texture and a first end (21) of a take-up strip (20), a second end (22) of the take-up strip being fixed onto the storage mandrel (340), - after winding the fibrous texture (200) onto the injection mold (430), separating the connection (50) between the end (210) of the fibrous texture (200) and the first end (21) of the take-up strip (20), and in that the connection (50) between the end of the fibrous texture and the first end of the take-up strip has deformability in the transverse direction (D T ) in order to follow the movements of the fibrous texture in said transverse direction (D T ).

2. The method of claim 1, wherein the connection (50) between the end (210) of the fibrous texture (200) and the first end (21) of the take-up strip (20) is achieved by providing a spiral attachment (61) around superimposed portions (210a, 21a) of the end (210) of the fibrous texture (200) and the first end (21) of the take-up strip (20) and around at least two connecting rods (62, 63) placed respectively on said portions (210a, 21a) and extending in the transverse direction (D T ), each connecting rod having flexibility in the transverse direction.

3. Method according to claim 1, wherein the connection (50) between the end (210) of the fibrous texture (200) and the first end (21) of the take-up strip (20) is made by a zipper (70) comprising first and second ribbons (71, 72) provided, along one of their edges, with hooking means (73, 74) and a slider (75) which slides along the edges of the ribbons to lock or unlock the hooking means, the first ribbon (71) being fixed to the first end (21) of the take-up strip (20) and the second ribbon (72) being fixed to the end (210) of the fibrous texture (200).

4. Method according to claim 1, in which the connection (50) between the end (210) of the fibrous texture (200) and the first end (21) of the take-up strip (20) is made by sewing (81) superimposed portions (210a, 21a) of the end (210) of the fibrous texture (200) and the first end (21) of the take-up strip (20).

5. The method of claim 1, wherein the connection (50) between the end (210) of the fibrous texture (200) and the first end (21) of the take-up strip (20) is made by sewing (91) a folded portion (210b) of the end (210) of the fibrous texture (200) with a folded portion (21b) of the first end (21) of the take-up strip (20).

6. A method according to any one of claims 1 to 5, wherein the length of the take-up strip (20) is at least equal to a conveying distance between the storage mandrel and the injection mold.

7. A method according to any one of claims 1 to 6, wherein the connection (20) made between the end (210) of the fibrous texture (200) and the first end (21) of the take-up strip (20) has an excess thickness corresponding to at most 150% of the thickness of the fibrous texture (200).

8. A method according to any one of claims 1 to 7, wherein the tension applied to the fibrous texture (200) during its winding onto the injection mold is at least 2 N per warp thread of the fibrous texture.

9. A method according to any one of claims 1 to 8, wherein the fibrous texture (200) is woven with yarns made of carbon fibers, glass fibers or a mixture of carbon fibers and glass fibers.

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