Web of impregnated fibrous material, method for producing same and use thereof for producing three-dimensional composite parts - Patents.com

Abstract

The present invention relates to a web of impregnated fibrous material comprising N individual tapes of fibrous material laminated and / or bonded to one another, said N tapes being at least partially adhered to one another and capable of overlapping. According to the invention, the tapes of fibrous material comprise continuous fibers impregnated with at least one thermoplastic polymer and optionally a chain extender. The web has a cross section perpendicular to the axis of the fibers, which cross section has a cross section of S th In a cross section perpendicular to the fiber axis, the surface area S is substantially equal to the sum of the surfaces of the individual original tapes, and S th is equal to N x l x Ep, l representing the average width of the tape, Ep representing the average thickness of the tape, N being between 2 and 2,000, characterized in that the average thickness of each of the individual tapes is less than or equal to 150 μm, preferably less than or equal to 100 μm, in particular between 10 and 100 μm. [Selection diagram] None

Description

[Technical Field]

[0001] The present invention relates to a web of impregnated fibrous material comprising N individual tapes of fibrous material in the form of continuous fibres, stacked and / or bonded to one another, and which may at least partially overlap, and at least one thermoplastic polymer.

[0002] The present invention also relates to a method for producing an impregnated fibrous material in the form of a web, with reduced production costs and high production speeds.

[0003] The invention also relates to the use of an impregnated fibrous material in the form of a web for producing a three-dimensional composite part. [Background technology]

[0004] The production of fibrous materials impregnated with a thermoplastic polymer or a mixture of thermoplastic polymers, also referred to as thermoplastic resins, can be carried out by continuously passing the fibers through a molten bath of the thermoplastic polymer containing an organic solvent such as benzophenone, or through an aqueous dispersion as disclosed in EP 0 324 680, by continuously passing the fibers through a fluidized bed, or by continuously spraying the fibers, particularly electrostatically, or also by molten route, particularly pultrusion as disclosed in US 2014 / 0005331 (A1). This allows these impregnated fibrous materials to be molded in the form of calibrated strips or tapes that can be used to produce composite materials. These impregnated fibrous materials are used in the production of structural components with a view to maintaining mechanical strength comparable to that achieved with metallic structural components, ensuring electrostatic charge dissipation, and / or ensuring thermal and / or chemical protection, while at the same time reducing the weight of the material.

[0005] Such impregnated fiber materials are particularly intended for producing lightweight composite materials for the manufacture of machine parts having a three-dimensional structure and having good mechanical and thermal strength properties, as well as the ability to dissipate electrostatic charges, i.e. properties suitable for the manufacture of parts, in particular in the fields of machinery, aeronautics, automobiles, energy, architecture (buildings), health and medicine, sports and leisure, furniture and urban furniture, and electronics. The composite materials are thus used for the production of three-dimensional (3D) parts, and can be produced by known robot-assisted strip placement methods, such as the automated fiber placement (AFP) method. Summary of the Invention

[0006] In the present invention, "fibrous material" refers to an assembly of individual reinforcing fibers, which are provided in the form of individual tapes after being impregnated with resin.

[0007] The term "individual tape" refers to a semi-finished strip of small thickness, not calibrated in width and thickness, consisting of a single roving of fiber or a thin tape of one or more fiber rovings, calibrated in thickness and width.

[0008] In all instances, the thickness of the tape is 150 μm or less, preferably 100 μm or less.

[0009] The tapes are then laminated and / or bonded together in the form of a web, which is of calibrated thickness but not necessarily of calibrated width.

[0010] When the thickness and width are calibrated, it is called a calibrated web.

[0011] If the geometry of the three-dimensional composite part is not overly complex, it is advantageous to manufacture the composite part from a web, allowing for increased productivity in robotic placement (for molding) of the pre-finished product.

[0012] The fibers that can be used in the fibrous material composition can have various linear basis weights or yardages or thread counts or "tex" and / or various numbers in the roving. Similarly, the most commonly used rovings are composed of fibers with a density of 600 to 4,800 tex for glass fibers and 3,000 (3K), 6,000 (6K), 12,000 (12K), 24,000 (24K), 48,000 (48K), 50,000 (50K), or 400,000 (400K) for carbon fibers. For example, carbon fibers generally have diameters of approximately 7 to 8 μm, while glass fibers have diameters of approximately 13, 15, 17, or 20 μm.

[0013] Since the linear basis weight of the fibers is predetermined and therefore also the average width of the resulting tape, it is not possible to directly obtain a web with any average thickness, since this would require rovings with some fibers that are not on the market.

[0014] Therefore, to obtain webs of various sizes, individual tapes of a specified thickness, each having a roving number that is a multiple of 3K, 6K, 12K, 24K, 48K, 50K, or 400K, would need to be laminated and / or bonded to one another, and such tapes are not currently available on the market.

[0015] The present invention therefore relates to a web of impregnated fibrous material comprising N individual tapes of fibrous material laminated and / or bonded to one another, said N individual tapes being adhered to one another and capable of at least partially overlapping, said individual tapes of fibrous material comprising continuous fibres impregnated with at least one thermoplastic polymer and optionally a chain extender, said web having a cross section perpendicular to the fibre axis that is: S thIn a cross section perpendicular to the fiber axis, the surface area S is substantially equal to the sum of the surfaces of the individual original tapes, and S th is equal to N x l x Ep, l representing the average width of the tapes, Ep representing the average thickness of the tapes, N being between 2 and 2,000, and the average thickness of each of the individual tapes being less than or equal to 150 μm, preferably less than or equal to 100 μm, in particular between 10 and 100 μm.

[0016] In one embodiment, polyarylsulfides, in particular polyphenylene sulfide (PPS), are excluded from the definition of thermoplastic polymers. The expression "laminated and / or bonded" means that the tapes are physically bonded to each other. [Brief explanation of the drawings]

[0017] [Figure 1] 1 shows an example of a vessel provided with a support. [Figure 2] 1 shows an example of a vessel with a fluidized bed, where the support is a cylindrical compression roller. [Figure 3] An embodiment using a single compression roller, a vessel (30) with a spray gun (31) for spraying powder (32) is shown, in which a single cylindrical compression roller (33) is present and exhibits an angle α"1. [Figure 4] 1 shows a schematic of a single heating system for heating the pre-impregnated fibrous material and the use of three rollers to finish the impregnation. [Figure 5] 1 shows a photograph taken with an optical microscope of a cross section of a SGL, 50K carbon fiber roving impregnated with PA BACT / 10T polyamide powder with D50=108 μm (D90=198 μm and D10=48.3 μm) according to Example 1 and as disclosed in WO 2015 / 121583 (before calendering). [Figure 6]FIG. 1 shows a photograph taken with an optical microscope of the cross section of a SGL, 50K carbon fiber roving impregnated with PA BACT / 10T polyamide powder (41 / 59 molar ratio) with D50=108 μm (D90=198 μm and D10=48.3 μm) according to Example 2 of the present invention (before calendering). [Figure 7] An embodiment (40) of the lamination of three strips (obtained in FIG. 6) formed to 12.7 mm to obtain a web width of 12.7 mm is shown. [Figure 8] FIG. 1 shows a photograph taken with an optical microscope of a cross section of a Toray (T700 12k 31E) carbon fiber roving impregnated with PA11 / BACT polyamide powder (33 / 67 molar ratio) with D50=108 μm (D90=198 μm and D10=48.3 μm) according to Example 2 of the present invention (before calendering). [Figure 9] FIG. 1 shows a photograph taken with an optical microscope of a cross section of a Toray (T700 12k 31E) carbon fiber roving impregnated with PA6I / 6T polyamide powder (45 / 55 molar ratio) with D50=136 μm (D90=225 μm and D10=75 μm) according to Example 3 of the present invention (before calendering). [Figure 10] FIG. 1 shows a photograph taken with an optical microscope of the cross section of a carbon fiber roving (Toray T700 12k 31E carbon fiber) impregnated with PA MPMDT / 10T powder (41 / 59 molar ratio) with D50=157 μm (D90=301 μm and D10=58 μm) according to Example 4 of the present invention (before calendering). DETAILED DESCRIPTION OF THE INVENTION

[0018] The expression "adhered to one another" means that the tapes are joined or welded or fusion welded or glued together, in particular by a heating system.

[0019] The bonding is achieved without the use of external binders or adhesive-type external compounds, but only by melting the polymers present in the respective tapes.

[0020] Thus, the tapes cannot be placed flush above and below or next to each other without adhesive to each other.

[0021] The phrase "the N individual tapes can at least partially overlap" means that the individual tapes are not completely joined edge to edge and can therefore overlap adjacent tapes. This can also mean, for example, that two tapes are joined to each other and that a third tape is not 100% laminated on one of the two tapes but overlaps the two tapes. If the web is made up of at least two layers of tape, the phrase "the N tapes can at least partially overlap" can also mean that the individual tapes from one layer overlap the individual tapes from the layer below.

[0022] In other words, up to 50% of the surface of the tape can overlap with at least one other tape.

[0023] In particular, up to 40%, preferably up to 30%, more preferably up to 20%, even more preferably up to 10%, in particular up to 5% of the surface of the tape may overlap with at least one other tape.

[0024] The expression "substantially equal to the sum of the surfaces of each of the original individual tapes in a cross section perpendicular to the fiber axis" means that the cross-sectional area S of the web perpendicular to the fiber axis is equal to the theoretical area S th + / -25%, especially S th + / -10%, especially S th + / -5%, especially S th + / -2%, preferably S th -5%, even more preferably S th -10% and S th means it is equal to -25%.

[0025] This difference is due to the presence of pores at the contact surface of the tapes after assembly to form the web, or conversely, the reduction of residual pores in each tape during handling of the assembly.

[0026] Therefore, S th corresponds to the theoretical surface area of ​​a cross section perpendicular to the axis of the fibers in the web.

[0027] Throughout this disclosure, the width of a web corresponds to the average width and the thickness of a web corresponds to the average thickness, i.e., the average width and thickness over the entire length of the web, which means that the width and thickness can vary along the web.

[0028] Advantageously, in the absence of reheating, the impregnated fibrous material web is inflexible.

[0029] This means that the web cannot assume a complex shape at room temperature, and the web can assume a complex shape only above the Tg of the resin, preferably above the Tm of the resin if the resin is semi-crystalline at the Tm of the resin. In other words, the web does not have drapeability.

[0030] In one embodiment, the individual tapes are thin and consist of strips, the average thickness of which is less than or equal to 100 μm, in particular between 10 and 100 μm.

[0031] A method for verifying that the average thickness is 100 μm or less is to measure a statistically representative sample of the strip by non-destructive measurement means.

[0032] Throughout this disclosure, the width of a strip corresponds to the average width, and the thickness of a strip corresponds to the average thickness, i.e., the average width and thickness over the entire length of the strip. This means that the width and thickness may vary along the strip, but the thickness will be, on average, 100 μm or less. A way to ensure that the average thickness over the entire length of the strip is less than 100 μm is to measure it on a statistically representative sample of the strip by non-destructive measuring means.

[0033] The expression "uncalibrated width strip" means that the width of the strip is not constant, but is possibly equal to l+ / -20%, in particular l+ / -15%, in particular l+ / -10%, where l represents the average width.

[0034] The expression "uncalibrated thickness strip" means that the thickness of the strip is not constant over its entire length, but that the thickness can be equal to e+ / -20%, in particular e+ / -15%, in particular e+ / -10%, where e represents the average thickness.

[0035] Advantageously, the expressions "uncalibrated width" and "uncalibrated thickness" mean that the width is equal to l+ / -20% of the average width and the thickness is equal to e+ / -20% of the average thickness, respectively.

[0036] Advantageously, the expressions "uncalibrated width" and "uncalibrated thickness" mean that the width is equal to l+ / -20% of the average width and the thickness is equal to e+ / -15% of the average thickness, respectively.

[0037] Advantageously, the expressions "uncalibrated width" and "uncalibrated thickness" mean that the width is equal to l+ / -20% of the average width and the thickness is equal to e+ / -10% of the average thickness, respectively.

[0038] Advantageously, the expressions "uncalibrated width" and "uncalibrated thickness" mean that the width is equal to l+ / -15% of the average width and the thickness is equal to e+ / -20% of the average thickness, respectively.

[0039] Advantageously, the expressions "uncalibrated width" and "uncalibrated thickness" mean that the width is equal to l+ / -10% of the average width and the thickness is equal to e+ / -20% of the average thickness, respectively.

[0040] Advantageously, the expressions "uncalibrated width" and "uncalibrated thickness" mean that the width is equal to l+ / -15% of the average width and the thickness is equal to e+ / -15% of the average thickness, respectively.

[0041] Advantageously, the expressions "uncalibrated width" and "uncalibrated thickness" mean that the width is equal to l+ / -10% of the average width and the thickness is equal to e+ / -15% of the average thickness, respectively.

[0042] Advantageously, the expressions "uncalibrated width" and "uncalibrated thickness" mean that the width is equal to l+ / -15% of the average width and the thickness is equal to e+ / -10% of the average thickness, respectively.

[0043] Advantageously, the expressions "uncalibrated width" and "uncalibrated thickness" mean that the width is equal to l+ / -10% of the average width and the thickness is equal to e+ / -10% of the average thickness, respectively.

[0044] In another embodiment, the individual tapes consist of "thin tapes" with an average thickness of less than 100 μm, in particular between 10 and 100 μm.

[0045] A method for verifying that the average thickness is 100 μm or less is to measure a statistically representative sample of the thin tape by non-destructive measurement means.

[0046] Throughout this disclosure, the thickness of the thin tape corresponds to the average thickness, i.e., the average thickness over the entire length of the thin tape. This means that the thickness may vary along the thin tape, but the thickness is, on average, 100 μm or less. A way to verify that the average thickness over the entire length of the thin tape is less than 100 μm is to measure it on a statistically representative sample of the thin tape by non-destructive measuring means.

[0047] The width of the thin tape is calibrated and therefore constant over the entire length of the thin tape.

[0048] In the case of a web, the thickness corresponds to the average thickness, i.e. the average thickness over the entire length of the web, which means that the thickness may vary along the web.

[0049] In the case of a web, the width corresponds to the average width over the entire length of the web.

[0050] For a calibrated web, the width of the web is constant along the entire length of the web.

[0051] The expression "calibrated width" means that the width of the thin tape or calibrated web is constant over its entire length, and the width may be equal to l + / - 5%, in particular l + / - 2%, where l represents the average width.

[0052] The expression "calibrated thickness" means that the thickness of a thin tape or web, calibrated or uncalibrated, is constant over its entire length, and the thickness may be equal to e+ / -5%, in particular the thickness is equal to e+ / -2%, where e represents the average thickness.

[0053] Advantageously, the expressions "calibrated width" and "calibrated thickness" mean that the width is equal to l+ / -5% of the average width and the thickness is equal to e+ / -5% of the average thickness, respectively.

[0054] Advantageously, the expressions "calibrated width" and "calibrated thickness" mean that the width is equal to l+ / -5% and the thickness is equal to e+ / -2%, respectively, of the average width.

[0055] Advantageously, the expressions "calibrated width" and "calibrated thickness" mean that the width is equal to l+ / -2% of the average width and the thickness is equal to e+ / -5% of the average thickness, respectively.

[0056] Advantageously, the expressions "calibrated width" and "calibrated thickness" mean that the width is equal to l+ / -2% of the average width and the thickness is equal to e+ / -2% of the average thickness, respectively.

[0057] The expression "substantially equal" means that in a cross section perpendicular to the fiber axis, the surface area S of the web is equal to the sum of the surface areas of the cross sections of each of the original individual tapes, i.e., S th + / -25%, especially S th + / -10%, especially S th + / -5%, especially S th + / -2%, preferably S th -5%, even more preferably S th -10% and S th This means it's -25%.

[0058] N between 2 and 2,000 means that at a minimum: - two individual tapes are joined together to form a web having an average thickness of one individual tape and an average width substantially equal to the average width of two individual tapes; or - one of the two individual tapes is laminated to form a web having an average thickness substantially equal to the thickness of two individual tapes and an average width substantially equal to the average width of one individual tape; or - one of the two individual tapes is partially laminated to form a web having an average thickness that varies substantially between the average thickness of the individual tape and the average thickness of the two individual tapes, and an average width that is substantially between the average width of the individual tape and the average width of the two joined individual tapes.

[0059] Apart from the two tapes, there are three other configurations: - the individual tapes are joined together to form a strip having the average thickness of one individual tape and an average width substantially equal to the average width of the individual tapes, or - the individual tapes are laminated to form a strip having an average thickness substantially equal to the average thickness of the individual tapes and an average width substantially equal to the average width of one individual tape; or - A portion of each tape is joined and another portion of each tape is laminated together so that the total number of tapes from both portions is equal to N.

[0060] The expression "substantially equal" has the same meaning as above.

[0061] When more than two tapes (N tapes) are spliced ​​and laminated, the average thickness of the web may be constant across the width of the web, but may also vary across the width of the web depending on the calendering machine ultimately used to form it, with the total number of laminated and spliced ​​tapes equal to N between 2 and 2,000.

[0062] The web may have an average width greater than, less than, or equal to the sum of the average widths of the N individual tapes that are joined together, and an average thickness greater than, less than, or equal to the sum of the average thicknesses of the N individual tapes that are stacked together, because the joining and stacking, if any, may either reduce the porosity of each tape or create holes between the joined or stacked tapes.

[0063] This means that the actual surface area S of the web in a cross section perpendicular to the fiber axis is equal to the sum of the surface areas of each of the original individual tapes in a cross section perpendicular to the fiber axis, i.e., S th + / -25%, especially S th + / -10%, especially S th + / -5%, especially S th + / -2%, preferably S th -5%, even more preferably S th -10% and S th This is why it is -25%.

[0064] In one embodiment, the porosity level of each of the individual impregnated tapes is less than 10%, particularly less than 5%, especially less than 2%.

[0065] In another embodiment, the porosity level of said web of impregnated fibrous material is less than 10%, particularly less than 5%, especially less than 2%.

[0066] In yet another embodiment, the porosity level of each of the impregnated individual tapes is less than 10%, in particular less than 5%, in particular less than 2%, and the porosity level of said web of impregnated fibrous material is less than 10%, in particular less than 5%, in particular less than 2%.

[0067] Advantageously, the porosity level of the initial tape has a porosity between 5 and 10%, and the porosity level of the web is less than 5%.

[0068] Advantageously, the porosity level of the initial tape has a porosity between 2 and 5%, and the porosity level of the web is less than 2%.

[0069] Thus, in these last two embodiments, the appearance of the web is improved compared to the initial appearance of the individual tapes.

[0070] said web of fibrous material comprises Nl tapes across its width and Nep tapes across its thickness; TIFF0007737798000001.tif17170, and each individual tape comprises a number of fibers, in particular carbon fibers, selected from a number of multiples of 3,000 or 50,000 fibers.

[0071] Advantageously, each individual tape comprises several carbon fibers selected from m×12K fibers, n×24K fibers, p×48K, q×50K fibers and w×400K, where m is between 1 and 40, in particular between 1 and 4, n is between 1 and 20, q is between 1 and 10, p is between 1 and 10, in particular 1, and w is equal to 1.

[0072] The thickness of the web may be constant across the width of the web, ie, if the assembly of tapes all have the same thickness, the number of tapes of thickness Nep is the same at any point on the web.

[0073] Conversely, the thickness of the web may vary, in particular depending on the width of the web, i.e. if the tapes all have the same thickness, the number of tapes of thickness Nep will vary depending on the position considered across the width of the web.

[0074] In any case, the total number of tapes, N, is between 2 and 2,000.

[0075] The N tapes of the web of impregnated fibrous material as defined above may consist of the same fibrous material or of different fibrous materials, in particular of the same fibrous material.

[0076] Thus, for example, there may be at least one tape made of a carbon fiber based fibrous material and at least one tape made of a glass fiber based fibrous material.

[0077] It does not depart from the scope of the invention if at least one of the tapes is made of a fibrous material, for example a mixture of glass and carbon fibres.

[0078] Advantageously, said N tapes in said web of impregnated fibrous material as defined above are made of the same fibrous material.

[0079] It does not depart from the scope of the invention if the yards of fiber of the same or different properties are the same or different in both thickness (stacking of Nep tapes) and width (parallel or spliced ​​Nl tapes) within an assembly of N tapes.

[0080] Thus, for example, it is possible to bond and / or laminate a 50K carbon fiber based tape with a 24K carbon fiber based tape.

[0081] However, it is also possible to bond and / or laminate a 50K carbon fiber based tape with a glass fiber based tape having a basis weight equal to 2,400 Tex.

[0082] In one embodiment, the N tapes have the same individual average thickness and average width, and the average thickness of the web TIFF0007737798000002.tif7170 is TIFF0007737798000003.tif is equal to 9170xer, TIFF0007737798000004.tif9170 is the average number of tapes of thickness, er is the average thickness of each individual tape, and er is the average width of the web TIFF0007737798000005.tif10170 is TIFF0007737798000006.tif is equal to 9170×lr, TIFF0007737798000007.tif8170 is the average number of tapes in width and lr is the average width of an individual tape.

[0083] In this embodiment, the surface area S of the web in a cross section perpendicular to the fiber axis is equal to the theoretical surface area Sth of the web in a cross section perpendicular to the fiber axis: therefore, a porosity level between the average value calculated for the N tapes before assembly and the final web resulting from assembly is maintained. Another possible case is when the pores, all of which have the same porosity, can, for example, change location, i.e., from "internal" pores in each tape (i.e., in the core of each tape) to "external" pores resulting from pore generation during assembly, where the "internal" pores in each tape do not change during tape assembly and the "external" pores after assembly are negligible.

[0084] In another embodiment, the average thickness and average width of the N individual tapes are the same, and the average thickness of the web is TIFF0007737798000008.tif8170 is TIFF0007737798000009.tif9170×er, TIFF0007737798000010.tif10170 is the average number of tapes of thickness, er is the average thickness of each individual tape, and er is the average width of the web TIFF0007737798000011.tif9170 is TIFF0007737798000012.tif is less than 9170×lr, TIFF0007737798000013.tif9170 is the average number of tapes in width and lr is the average width of an individual tape.

[0085] In this embodiment, the holes in the individual tapes after assembly are reduced and the web can have a constant average thickness across its width or can have different thicknesses depending on where in the web is considered to be across its width.

[0086] In yet another embodiment, the average thickness and average width of the N individual tapes are the same, and the average thickness of the web is TIFF0007737798000014.tif9170 is TIFF0007737798000015.tif9170×er larger, TIFF0007737798000016.tif9170 is the average number of tapes of thickness, er is the average thickness of each individual tape, and er is the average width of the web TIFF0007737798000017.tif9170 is TIFF0007737798000018.tif9170×lr larger, TIFF0007737798000019.tif9170 is the average number of tapes in width and lr is the average width of an individual tape.

[0087] In this embodiment, holes are created between the assembled tapes and the web may have a constant average thickness across its width or may have different thicknesses depending on where in the width of the web is considered.

[0088] In this embodiment, the overall porosity level may still be maintained, but the pores may migrate from the inside to the outside of the tape during assembly of the tapes, towards the interface between the tapes.

[0089] In other words, if there are N tapes with porosity P / N therein, the total porosity is equal to P.

[0090] When the width and thickness of these tapes are assembled by stacking them, the porosity within each tape may decrease, then P' / N = P / N - ε / N, where ε / N is the decrease in porosity within each tape and is a result of the tape assembly method. But in parallel, holes may appear between the tapes after assembly, which is also a result of the tape assembly method, and then this porosity becomes P" / N.

[0091] If the total pore drop ε in the tape is equal to P″ generated between the rovings, the overall porosity level is maintained.

[0092] According to a first embodiment of the web of fibrous material, N tapes of the web of impregnated fibrous material as defined above are stacked, the number of width tapes Nl being equal to 1 and the number of thickness tapes Nep being between 2 and 2,000.

[0093] Thus, in this embodiment, there is only one tape width and 2-2000 tapes thickness.

[0094] According to a second form of the web of fibrous material, N tapes in the web of impregnated fibrous material defined above are joined together, the number of thickness tapes Nep being equal to 1 and the number of width tapes Nl being between 2 and 2,000.

[0095] Thus, in this embodiment, there is only one tape thickness and 2-2,000 tapes width.

[0096] According to a third form of the web of fibrous material, N tapes of the web of impregnated fibrous material as defined above are stacked and bonded together.

[0097] In this case, all scenarios are possible, with the thickness of the web being constant over its width, or with a thickness that varies depending on the point considered in its width.

[0098] In yet another embodiment, the N individual tapes have different average thicknesses and / or widths, and the average thickness of the web is: TIFF0007737798000020.tif9170 × the average thickness of each individual tape, and the average width of the web is TIFF0007737798000021.tif9170 x equal to the average width of each individual tape.

[0099] In a first alternative, the thickness of said web of impregnated fibrous material as defined above, consisting of said N laminated and / or spliced ​​tapes, may vary over its width.

[0100] In this alternative, regardless of whether the variation in thickness of the web as a function of position along the width of the web and its width is directly attributable to the variation in thickness from one tape to another, either there are a number of stacked tapes of the same thickness, or furthermore, depending on the point considered in its width, there are no stacked tapes of the same thickness, and the variation in the number of stacked tapes does not offset the variation in thickness from one tape to another, thereby allowing for a particular geometry for the web according to its width.

[0101] In a second alternative, the thickness of said web of impregnated fibrous material as defined above, consisting of said N laminated and / or spliced ​​tapes, is constant over its entire width.

[0102] This latter alternative allows for a number of stacked tapes of the same thickness to offset thickness variations from one tape to another.

[0103] The fiber content by volume of the various webs as defined above is constant for at least 70% of the volume of each of the N tapes of fibrous material laminated and / or bonded in the web, the N tapes can overlap at least partially, in particular for at least 80% of the volume of each of the N tapes of fibrous material laminated and / or bonded in the web, the N tapes can overlap at least partially, in particular for at least 90% of the volume of each of the N tapes of fibrous material laminated and / or bonded in the web, the N tapes can overlap at least partially, in particular for at least 95% of the volume of each of the N tapes of fibrous material laminated and / or bonded in the web, and the N tapes can at least partially overlap.

[0104] The fiber content is in the range of 45 to 65% by volume, preferably 50 to 60% by volume, and in particular 54 to 60% by volume, for each of the N tapes of fibrous material that are laminated and / or joined to the web, and the N tapes can at least partially overlap in the web of fibrous material.

[0105] Advantageously, the fiber content by volume of the various webs as defined above is constant for at least 70% of the volume of each of the N tapes of fibrous material laminated and / or bonded in said web, and said N tapes can overlap at least partially, in particular for at least 80% of the volume of each of the N tapes of fibrous material laminated and / or bonded in said web, and said N tapes can overlap at least partially, in particular for at least 90% of the volume of each of the N tapes of fibrous material laminated and / or bonded in said web. wherein the N tapes are capable of at least partially overlapping, in particular with at least 95% of the volume of each of the N tapes of fibrous material that are laminated and / or bonded in the web, and wherein the N tapes are capable of at least partially overlapping, and the fiber content is between 45 and 65% by volume, preferably between 50 and 60% by volume, in particular between 54 and 60%, for each of the N tapes of fibrous material that are laminated and / or bonded in the web, and wherein the N tapes are capable of at least partially overlapping in the web of fibrous material.

[0106] Advantageously, said N tapes of fibrous material of the web of fibrous material defined above are made of the same at least one thermoplastic polymer.

[0107] This means that each of the tapes is made of the same polymer, but the polymer in each tape may be a mixture of polymers, for example PEKK and PEI.

[0108] In another embodiment, the at least one thermoplastic polymer of the N tapes of assembled and / or bonded fibrous material may be different, provided that the polymers constituting the laminated and / or bonded tapes (the N tapes may at least partially overlap) are compatible or partially miscible.

[0109] In one embodiment, the web of fibrous material as defined above consists of Nep tapes stacked and Nl tapes bonded together, the number of thickness tapes Nep being between 1 and 4 and the number of width tapes Nl being between 1 and 94.

[0110] Advantageously, the number Nep of stacked tapes of thickness is the same for all Nl tapes, and the average thickness is constant over the width of said web.

[0111] In one embodiment, the number of thickness tapes Nep is selected from two and four, and the number of width tapes Nl is one.

[0112] The web is therefore one tape wide and two or four tapes thick.

[0113] In another embodiment, the number of thickness tapes Nep is 1 and the number of width tapes Nl is selected from 24 and 32.

[0114] The web is therefore of a single thickness across the width of 24 or 32 tapes.

[0115] In yet another embodiment, the number of thickness tapes Nep is 2 and the number of width tapes Nl is selected from 46, 62 and 92 tapes.

[0116] Advantageously, said webs made of fibrous material as defined above have cross-sectional surface dimensions, expressed by an average width and an average thickness, selected from the following: 300mm x 2mm; 200mm x 2mm; 150mm x 2mm; 100mm x 2mm; 596.9mm x 1mm; 393.7mm x 1mm; 292mm x 1mm; 200mm x 1mm; 150mm x 1mm; 100mm x 1mm; 15mm x 0.25mm, 15mm x 0.225mm, 14mm x 0.265mm, 14mm x 0.240mm, 12.7mm x 0.265mm, 12.7mm x 0.189mm, 596.9mm x 0.12mm; 393.7mm x 0.12mm; 292.1mm x 0.12mm.

[0117] According to another aspect, the invention relates to the use of a web of impregnated fibrous material, such as described above, for manufacturing three-dimensional composite parts by automated placement of said web by a robot.

[0118] All properties defined for the Web are valid for the above uses of the Web.

[0119] Advantageously, said manufacture of said composite parts relates to the transport sector, in particular automotive, oil and gas, in particular offshore, gas storage, aviation equipment, ships, railways; renewable energy, in particular wind energy, water turbines, energy storage devices, solar panels; thermal protection panels, sports and leisure, health and medicine, and electronics.

[0120] According to another aspect, the invention relates to a three-dimensional composite part, characterized in that it results from the use of at least one web of impregnated fibrous material as defined above.

[0121] All properties defined for the web are valid for the composite part.

[0122] According to yet another aspect, the present invention relates to a method for preparing a web of fibrous material as defined above, comprising a step of stacking and / or bonding said tapes of fibrous material as defined above, characterized in that said N tapes can at least partially overlap one another.

[0123] All the properties defined for the web are valid for the preparation method.

[0124] Advantageously, the laminating and / or joining process is carried out using at least one of the following systems: 1) heating the tape with at least one heating system, then passing the tape over at least one support provided with a heating system, and then passing the tape over a non-heated calendering machine; 2) passing the tape over at least one support provided with a heating system and then passing the tape over a heated calender; 3) heating the tape with at least one heating system and then passing the tape over a heated calender; 4) heating the tape with at least one heating system and then passing the tape through a warm drawing plate and over a heated calender; This is done by:

[0125] Advantageously, said at least one heating system is selected from infrared lamps, UV lamps, convection heating, microwave heating, laser heating and radio frequency (HF) heating.

[0126] In one embodiment, the above defined method comprises the step of: spareIt is characterized in that it further comprises a preliminary step of heating the impregnated fibrous material and terminating the impregnation to obtain an impregnated fibrous material consisting of a tape in the form of a strip having an average thickness of less than 100 μm, in particular between 10 μm and 100 μm, and optionally a step of shaping and calibrating rovings of the impregnated fibrous material or the parallel rovings to obtain an impregnated fibrous material consisting of a tape in the form of a thin tape having an average thickness of less than 100 μm, in particular between 10 μm and 100 μm.

[0127] In another embodiment, the method defined above comprises: spare To obtain the impregnated fibrous material, the fibrous material can be impregnated in particular by powder deposition, by melt route, in particular by pultrusion, by crosshead extrusion of a molten thermoplastic polymer and optionally a chain extender, by continuous flow of the fibers in an aqueous thermoplastic polymer powder dispersion and optionally a chain extender, or an aqueous thermoplastic polymer particle dispersion and optionally a chain extender, or an aqueous thermoplastic polymer emulsion, or in a suspension, by a fluidized bed with or without at least one support (E'), by spraying with a nozzle or a spray gun, by dry route in a tank with or without at least one support (E'). spare The method is characterized by further comprising a pre-impregnation step.

[0128] In yet another embodiment, the method as defined above is characterized in that it further comprises a step of shaping the web by means of at least one notched calender, possibly a heated calender.

[0129] Advantageously, the method defined above comprises the steps of: i) spareTo obtain the impregnated fibrous material, the fibrous material can be impregnated in particular by powder deposition, by melt passage, in particular by pultrusion, by crosshead extrusion of molten polymer, by continuous flow of the fibers in an aqueous polymer powder dispersion or aqueous polymer particle dispersion or aqueous polymer emulsion or suspension, by a fluidized bed with or without at least one support (E'), by spraying with a nozzle or spray gun, by dry passage in a tank with or without at least one support (E'). spare impregnation step; ii) The above spare heating the impregnated fibrous material and terminating the impregnation to obtain an impregnated fibrous material consisting of a tape in the form of a strip having an average thickness of less than 100 μm, in particular between 10 μm and 100 μm; iii) optionally shaping and calibrating the rovings of the impregnated fibrous material or the parallel rovings to obtain an impregnated fibrous material consisting of a tape in the form of a thin tape having an average thickness of less than 100 μm, in particular between 10 μm and 100 μm; iv) laminating and / or bonding N tapes of fibrous material, said N tapes being made of at least one of the following systems: 1) heating the tape with at least one heating system, then passing the tape over at least one support provided with a heating system, and then passing the tape over a heated calender; 2) passing the tape over at least one support provided with a heating system and then passing the tape over a heated calender; 3) heating the tape with at least one heating system and then passing the tape over a heated calender; 4) heating the tape with at least one heating system and then passing the tape through a warm drawing plate and over a heated calender; - stacking and / or bonding N tapes of fibrous material, which may be at least partially overlapping, by v) shaping the web by at least one notched calender, optionally a heated calender; The present invention is characterized by comprising:

[0130] Advantageously, the process as defined above is characterized in that it is carried out at a speed of at least 10 m / min, in particular at least 20 m / min, preferably at least 30 m / min.

[0131] Since the impregnation and shaping and calibration steps are independent of the method for preparing the web, production rate is not critical with respect to the method of the present invention and is therefore not a limiting factor in productivity.

[0132] Steps (i), (ii) and (iii) are disclosed in more detail below in the section entitled "Method for preparing tapes, especially in the form of strips and thin tapes."

[0133] Step iv) is disclosed in more detail in the section "Method for preparing a tape in the form of a web."

[0134] polymer matrix Thermoplastic resin or thermoplastic polymer refers to a material that is generally solid at room temperature; this material may be semi-crystalline or amorphous; if the material is amorphous, it may soften during heating, especially after its glass transition temperature (Tg), and flow at higher temperatures; or if semi-crystalline, it may exhibit a sharp transition once it has passed its so-called melting temperature (Tm), becoming solid again when the temperature is reduced below its crystallization temperature (for semi-crystalline) or below its glass transition temperature (for amorphous).

[0135] Tg and Tm are determined by differential scanning calorimetry (DSC) according to standards 11357-2:2013 and 11357-3:2013, respectively.

[0136] As regards the polymer constituting the impregnation matrix for the fibrous material, it is advantageously a thermoplastic polymer or a mixture of thermoplastic polymers, which can be ground into powder form so that it can be used in devices such as tanks, in particular in fluidized beds or in aqueous media.

[0137] The vessel-type apparatus, particularly in fluidized beds, can be an open or closed system.

[0138] In one embodiment, polyarylsulfides, in particular polyphenylene sulfide (PPS), are excluded from the definition of polymers that make up the impregnated matrix of the fibrous material.

[0139] Optionally, the thermoplastic polymer or blend of thermoplastic polymers further comprises a carbon-based filler, in particular carbon black or a carbon-based nanofiller, preferably selected from graphene, carbon nanotubes, carbon nanofibrils or blends thereof, which are capable of conducting electricity or heat and therefore, when heated, can facilitate melting of the polymer matrix.

[0140] Optionally, said thermoplastic polymer comprises at least one additive chosen among, inter alia, catalysts, antioxidants, heat stabilizers, UV stabilizers, light stabilizers, lubricants, fillers, plasticizers, flame retardants, nucleating agents, chain extenders and pigments, electrical conductors, thermal conductors or mixtures thereof.

[0141] Advantageously, said additives are chosen from among flame retardants, electrical conductors and thermal conductors.

[0142] According to another variant, the thermoplastic polymer or mixture of thermoplastic polymers may also comprise a liquid crystal polymer or a cyclized polybutylene terephthalate or a mixture containing a cyclized polybutylene terephthalate, such as the CBT100 resin sold by CYCLICS CORPORATION. These compounds make it possible to fluidize the polymer matrix in the molten state, in particular for better penetration into the core of the fiber. spare One or the other of these compounds will be chosen depending on the nature of the polymer, or mixture of thermoplastic polymers, used to make the impregnated matrix, in particular its melting temperature.

[0143] The thermoplastic polymers that make up the impregnated matrix of the fibrous material are: - polymers and copolymers from the family of aliphatic, cycloaliphatic or semi-aromatic polyamides (PA) (also called polyphthalamides (PPA)), - polyureas, in particular aromatic polyureas; polymers and copolymers from the acrylic family, such as polyacrylates, in particular polymethyl methacrylate (PMMA) or its derivatives; - polymers and copolymers from the family of poly(aryl ether ketones) (PAEK), such as polyether ether ketones (PEEK), or poly(aryl ether ketone ketones) (PAEKK), such as poly(ether ketone ketones) (PEKK), or derivatives thereof; - aromatic polyether-imide (PEI), - polyarylsulfides, in particular polyphenylsulfide (PPS), - polyarylsulfides, in particular polyphenylene sulfone (PPSU), - polyolefins, especially polypropylene (PP); - Polylactic acid (PLA), - Polyvinyl alcohol (PVA), fluorinated polymers, in particular polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE) or polychlorotrifluoroethylene (PCTFE), and mixtures thereof You can choose from:

[0144] In one embodiment, the thermoplastic polymer that is included in the impregnated matrix of fibrous material is: - polymers and copolymers from the family of aliphatic, cycloaliphatic or semi-aromatic polyamides (PA) (also called polyphthalamides (PPA)), polyureas, in particular aromatic polyureas; polymers and copolymers from the acrylic family, such as polyacrylates, in particular polymethyl methacrylate (PMMA) or its derivatives; - polymers and copolymers from the family of poly(aryl ether ketones) (PAEK), such as polyether ether ketones (PEEK), or poly(aryl ether ketone ketones) (PAEKK), such as poly(ether ketone ketones) (PEKK), or derivatives thereof; - aromatic polyether-imide (PEI), - polyarylsulfides, in particular polyphenylene sulfone (PPSU), - polyolefins, especially polypropylene (PP); - Polylactic acid (PLA), - Polyvinyl alcohol (PVA), fluorinated polymers, in particular polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE) or polychlorotrifluoroethylene (PCTFE), and mixtures thereof You can choose from:

[0145] Advantageously, when said polymer is a mixture of two polymers P1 and P2, the proportion, on a weight basis, of polymers P1 and P2 is between 1 and 99% and 99 and 1%.

[0146] Advantageously, said thermoplastic polymer is a blend, spare If the impregnation method uses dry powders, the mixture may be spare It comes in powder form either from dry blending before introduction into the bath for impregnation, or by dry blending directly in the bath, or even by milling of preformed compounds in an extruder.

[0147] Advantageously, this mixture consists of powders obtained by dry blending before being introduced into the tank or directly in the tank, such a mixture of two polymers P1 and P2 being a mixture of PEKK and PEI.

[0148] Advantageously, the PEKK / PEI mixture is from 90-10% to 60-40% by weight, in particular from 90-10% to 70-30% by weight.

[0149] The thermoplastic polymer is the final non-reactive polymer that impregnates the fibrous material, or leads to said final non-reactive polymer, which also impregnates the fibrous material, but spare After impregnation, depending on the chain ends it has, it can correspond to a reactive prepolymer which can react with itself or with another prepolymer or with a chain extender, in particular during heating in a heated calender, or also to a reactive thermoplastic prepolymer, optionally partially polymerized with said chain extender, and which has a number-average molecular mass (Mn) ranging from 500 to 10,000, preferably from 4,000 to 8,000. Depending on the Tg and / or Tm of the polymer used, the partially polymerized reactive thermoplastic prepolymer can be converted into the non-reactive final polymer by heating.

[0150] The expression "non-reactive polymer" means that the molecular weight can no longer be significantly changed, i.e., when used, its number average molecular weight (Mn) changes by less than 50% and therefore corresponds to the final polyamide polymer in the thermoplastic matrix.

[0151] Conversely, the expression "reactive polymer" means that the molecular weight of said reactive polymer changes during its production, as reactive prepolymers react together by condensation, substitution, or with chain extenders by polyaddition, without elimination of volatile by-products, to reach the final (non-reactive) polyamide polymer in the thermoplastic matrix.

[0152] According to a first possibility, said prepolymer may comprise or consist of at least one carrier-reactive prepolymer (polyamide) having, on the same chain (i.e. on the same prepolymer), two terminal functional groups X' and Y', in particular X' and Y' being amine and carboxy, or carboxy and amine, respectively, which become co-reactive functional groups with each other upon condensation.

[0153] In this first possibility, said at least one reactive thermoplastic prepolymer, optionally partially polymerized with said chain extender, has a number average molecular weight (Mn) ranging from 500 to 10,000, preferably from 4,000 to 8,000.

[0154] According to a second possibility, the prepolymers can comprise or consist of at least two polyamide prepolymers that are reactive towards one another, each prepolymer having two identical terminal functional groups X' or Y' (the same for the same prepolymer and different between the two prepolymers), said functional group X' of a prepolymer being capable of reacting, in particular by condensation, only with said functional group Y' of the other prepolymer, in particular X' and Y' being amine and carboxyl, respectively, or carboxyl-terminated amine.

[0155] In this second possibility, said at least one reactive thermoplastic prepolymer, optionally partially polymerized with said chain extender, has a number average molecular weight (Mn) ranging from 500 to 10,000, preferably from 4,000 to 8,000.

[0156] According to a third possibility, the prepolymer may comprise or consist of at least one prepolymer of said thermoplastic polyamide polymer having n terminal reactive functional groups X chosen from among: -NH2, -CO2H and -OH, preferably NH2 and -CO2H, where n is 1 to 3, preferably 1 to 2, more preferably 1 or 2, especially 2; and at least one chain extender Y-A'-Y, preferably having a molecular mass of less than 500, more preferably less than 400, where A' is a hydrocarbon disubstituent having two identical terminal reactive functional groups Y which are reactive by polyaddition with at least one functional group X of said prepolymer a1).

[0157] In this second possibility, said at least one reactive thermoplastic prepolymer, optionally partially polymerized with said chain extender, has a number average molecular weight (Mn) ranging from 500 to 10,000, preferably from 4,000 to 8,000.

[0158] The number average molecular weight Mn of the final polymer of the thermoplastic matrix is ​​preferably in the range of 10 000 to 40 000, preferably 12 000 to 30 000. These Mn values ​​may correspond to an intrinsic viscosity of 0.8 or more, determined in m-cresol according to standard ISO 307:2007, depending on the solvent change (m-cresol instead of sulfuric acid, temperature 20°C).

[0159] Said reactive prepolymers according to the two options given above have a number average molecular weight Mn ranging from 500 to 10,000, preferably from 500 to 6,000, in particular from 2,500 to 6,000.

[0160] The Mn is determined in particular by calculation from the terminal functional groups determined by potentiometric titration in solution and the proportion of functional groups in the prepolymer. The mass Mn can also be determined by steric exclusion chromatography or by NMR.

[0161] The nomenclature used to define polyamides is described in ISO standard 1874-1:2011 "Plastiques - Materials polyamides (PA) pour moulage et extrusion - Partie 1: Designation", in particular page 3 (Tables 1 and 2), and is well known to those skilled in the art.

[0162] The polyamide can be a homopolyamide or a copolyamide, or a mixture thereof.

[0163] Advantageously, the prepolymers constituting the matrix are chosen from polyamides (PA), in particular chosen from aliphatic, cycloaliphatic and semi-aromatic polyamides (polyphthalamides) optionally modified with urea units, and their copolymers, polymethyl methacrylate (PPMA) and its copolymers, polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), PVDF, polyetherketoneketone (PEKK), polyetheretherketone (PEEK), fluorinated polymers, such as polyvinylidene fluoride (PVDF).

[0164] In one embodiment, the prepolymers constituting the matrix are chosen from polyamides (PA), in particular chosen from aliphatic, cycloaliphatic and semi-aromatic polyamides (polyphthalamides) optionally modified with urea units, and their copolymers, polymethyl methacrylate (PPMA) and its copolymers, polyetherimide (PEI), polyphenylene sulfone (PPSU), PVDF, polyetherketoneketone (PEKK), polyetheretherketone (PEEK), fluorinated polymers, such as polyvinylidene fluoride (PVDF).

[0165] Regarding the fluorinated polymer, it is possible to use a homopolymer of vinylidene fluoride (VDF, which has the formula CH═CF), or a copolymer of VDF, which contains, by weight, at least 50% by weight of VDF and at least one other monomer copolymerizable with VDF. The VDF content must be greater than 80% by weight, or even better, 90% by weight, to ensure good mechanical and chemical resistance of the structural parts, especially when exposed to thermal and chemical stress. The comonomer must be a fluorinated monomer, such as vinyl fluoride.

[0166] For structural parts that must be resistant to high temperatures, besides fluorinated polymers, PAEKs (polyaryletherketones), such as poly(etherketone) PEK, poly(etheretherketone) PEEK, poly(etherketoneketone) PEKK, poly(etherketoneetherketoneketone) PEKEKK, or PAs with a high glass transition temperature Tg, are advantageously used according to the invention.

[0167] Advantageously, the thermoplastic polymer is an amorphous polymer, such as one having a glass transition temperature Tg≧80°C, in particular ≧100°C, in particular ≧120°C, in particular ≧140°C, or a semi-crystalline polymer, such as one having a melting temperature Tm≧150°C.

[0168] Advantageously, said at least one thermoplastic prepolymer is chosen from polyamide, PEKK, PEI and mixtures of PEKK and PEI.

[0169] Advantageously, said polyamide is chosen from aliphatic polyamides, cycloaliphatic polyamides and semi-aromatic polyamides (polyphthalamides).

[0170] Advantageously, said aliphatic polyamide prepolymer is: - selected from polyamide 6 (PA-6), polyamide 11 (PA-11), polyamide 12 (PA-12), polyamide 66 (PA-66), polyamide 46 (PA-46), polyamide 610 (PA-610), polyamide 612 (PA-612), polyamide 1010 (PA-1010), polyamide 1012 (PA-1012), polyamide 11 / 1010 and polyamide 12 / 1010, or mixtures thereof or copolyamides thereof, and block copolymers, in particular polyamide / polyether (PEBA), said semi-aromatic polyamides being optionally modified by urea units, in particular PA-MXD6 and PA-MXD6; MXD10, or semi-aromatic polyamides of formula X / YAr as disclosed in EP 1505099, in particular semi-aromatic polyamides of formula A / XT, where A is selected from units resulting from at least one amino acid, at least one unit resulting from a lactam, and at least one unit corresponding to the formula (Ca diamine, Cb diacid), where "a" represents the number of carbon atoms in the diamine and "b" represents the number of carbon atoms in the diacid, "a" and "b" each being between 4 and 36, advantageously between 9 and 18, and the units (Ca diamine) are selected from aliphatic diamines, linear or branched cycloaliphatic diamines and alkylaromatic diamines, and the units (Cb diacid) are selected from aliphatic diacids, linear or branched diacids, cycloaliphatic diacids and aromatic diacids, XT are units resulting from the polycondensation of Cx diamines and terephthalic acid (x represents the number of carbon atoms in the Cx diamine, x is between 6 and 36, advantageously between 9 and 18), in particular polyamides having the formula A / 6T, A / 9T, A / 10T or A / 11T (A is as defined above), in particular polyamides PA6 / 6T, PA66 / 6T, PA6I / 6T, PA MPMDT / 6T, PA PA11 / 10T, PA11 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA11 / BACT, PA BACT / 10T / 6T).

[0171] T corresponds to terephthalic acid, MXD corresponds to m-xylylenediamine, MPMD corresponds to methylpentamethylenediamine, and BAC corresponds to bis(aminomethyl)cyclohexane.

[0172] Advantageously, said polyamide is a semi-aromatic polyamide chosen from PA MPMDT / 6T, PA PA11 / 10T, PA11 / BACT, PA11 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T, PA11 / BACT / 6T, PA11 / MPMDT / 10T, PA11 / BACT / 10T, PA11 / MXDT / 10T.

[0173] Fiber material: As regards the fibres constituting said fibrous material, they are in particular continuous fibres of inorganic, organic or vegetable origin in the form of rovings.

[0174] Advantageously, each individual tape contains several fibers, in particular carbon fibers selected from a multiple of 3,000 or 50,000 fibers.

[0175] Advantageously, each individual tape comprises a number of carbon fibers chosen from m×12,000 fibers, n×24,000 fibers and p×50,000 fibers, 270,000 fibers or 400,000 fibers, where m is between 1 and 40, in particular between 1 and 4, n is between 1 and 20 and p is between 1 and 10, in particular 1.

[0176] Advantageously, the basis weight in the case of glass fibres is greater than or equal to 1,200 Tex, in particular greater than or equal to 2,400 Tex, or greater than or equal to 4,800 Tex.

[0177] Inorganic fibers include, for example, carbon fibers, glass fibers, basalt or basalt-based fibers, silica fibers or silicon carbide fibers.

[0178] Organic fibers include, for example, fibers based on thermoplastic or thermosetting polymers, such as semi-aromatic polyamide fibers, aramid fibers or polyolefin fibers. Preferably, they are based on amorphous thermoplastic polymers, and when the thermoplastic polymer mixture is amorphous, spare The impregnated matrix has a glass transition temperature Tg higher than that of the polymer or thermoplastic polymer blend that constitutes the matrix, or the thermoplastic polymer matrix is ​​semi-crystalline. spare They have a glass transition temperature Tg higher than the Tm of the polymer constituting the impregnation matrix or of the thermoplastic polymer matrix. Advantageously, they are based on semi-crystalline thermoplastic polymers, and when the thermoplastic polymer mixture is amorphous, spare The impregnated matrix has a melting temperature Tm higher than the Tg of the polymer or thermoplastic polymer blend that constitutes the matrix, or the thermoplastic polymer matrix is ​​semi-crystalline. spare The Tm is higher than the melting temperature Tm of the polymer or thermoplastic polymer matrix that constitutes the impregnation matrix. Therefore, there is no risk of the organic fibers that make up the fibrous material melting during impregnation with the thermoplastic matrix of the final composite. Plant fibers include natural flax, hemp, lignin, bamboo, silk, especially spider silk, sisal, and other cellulose fibers, especially viscose. These plant fibers can be used pure, or they can be treated or coated with a coating layer to facilitate adhesion and impregnation with the thermoplastic polymer matrix.

[0179] Plant fibers may also correspond to fibers that contain support threads.

[0180] These component fibers can be used alone or in a mixture. Thus, organic fibers are more easily absorbed by thermoplastic polymers. spare Mixed with impregnated inorganic fibers, spare An impregnated fibrous material can be formed.

[0181] Preferably, the fibrous material is composed of continuous carbon, glass or silicon carbide fibers or mixtures thereof, in particular carbon fibers. The fibrous material is used in the form of a roving or several rovings.

[0182] In impregnated materials, also known as "ready to use," the polymer or mixture of thermoplastic impregnating polymers is uniformly and homogeneously distributed around the fibers. In this type of material, the thermoplastic impregnating polymer must be distributed as uniformly as possible within the fibers to achieve minimal porosity, i.e., minimal empty space between the fibers. In fact, the presence of pores in this type of material can act as stress concentration spots, for example, during mechanical tensile stress, which in turn can form crack initiation points in the impregnated fiber material, mechanically damaging it. Therefore, the uniform distribution of the polymer or mixture of polymers improves the mechanical strength and homogeneity of composite materials formed from these impregnated fiber materials.

[0183] Thus, when the impregnated material is "ready for use", spare The proportion of fibres in the impregnated fibre material is between 45 and 65% by volume, preferably between 50 and 60% by volume, in particular between 54 and 60% by volume.

[0184] The impregnation rate can be measured by image analysis of the cross section of the ribbon (e.g., using a microscope or optical or digital camera equipment) by dividing the surface area of ​​the ribbon impregnated with polymer by the total surface area of ​​the product (impregnated surface + pore surface). To obtain a good quality image, a cut piece of ribbon is preferably coated in its transverse direction with a standard polishing resin and polished according to standard protocols, allowing the sample to be viewed under a microscope with at least 6x magnification.

[0185] Advantageously, the porosity level of said impregnated fibrous material is less than 10%, in particular less than 5%, in particular less than 2%.

[0186] It should be noted that pore-free levels are difficult to achieve, so that advantageously the porosity level is higher than 0%, but below the levels listed above.

[0187] The porosity level corresponds to the independent porosity level and can be determined either by electron microscopy or as the relative deviation between the theoretical density and the experimental density of the impregnated fibrous material, as described in the Examples section of the present invention.

[0188] Method for preparing tapes, especially in the form of strips and thin tapes Tapes of impregnated fibrous material in the form of strips or thin tapes, in particular single-layer tapes, can be applied in two or three steps, respectively: Due to the polymer matrix spare a first step of impregnation, a second step of heating to complete the impregnation by means of at least one support part (E) for the strip and at least one heating system, and a third step of shaping and calibrating the thin tape. It can be prepared by

[0189] Advantageously, said at least one heating system is selected from infrared lamps, UV lamps, convection heating, microwave heating, laser heating and radio frequency (HF) heating.

[0190] First step: spare Impregnation spare Producing impregnated fiber materials spare The first step of impregnation can be carried out according to techniques well known to those skilled in the art and can in particular be chosen from those disclosed above.

[0191] They can thus be prepared by powder deposition, by the melt route, in particular by pultrusion, by crosshead extrusion of molten polymer, by continuous flow of the fibers in an aqueous polymer powder dispersion or aqueous polymer particle dispersion or aqueous polymer emulsion or suspension, by a fluidized bed with or without at least one support (E'), by spraying with a nozzle or a spray gun, by the dry route in a tank with or without at least one support (E'), spare This can be done by impregnation techniques.

[0192] The support may be a concave, convex or cylindrical compression roller, in particular cylindrical.

[0193] FIG. 1 shows an example of a vessel provided with a support, and FIG. 2 shows an example of a vessel with a fluidized bed, where the support is a cylindrical compression roller.

[0194] The same vessel can be used without the fluidized bed and equipped with a spray gun.

[0195] spare Impregnation may also be carried out by providing one or more supports (E") upstream of said system, in particular spare It can also be carried out using a system such as that defined above, which is present before the bath in which the impregnation takes place.

[0196] It should be noted that the support portions (E) and (E") can be identical or different, irrespective of the material or shape and their characteristics (diameter, length, width, height, etc. as a function of shape).

[0197] Melting Path: spare The impregnation process can be carried out by the melt route, in particular by pultrusion.

[0198] By melting route spareImpregnation techniques are known by those skilled in the art and are described in the above references.

[0199] spare The impregnation step is carried out in particular by cross-head extrusion of the polymer matrix, passing the roving(s) through the cross-head and then through a heated die, the cross-head being able to have fixed or rotating supports over which the rovings pass, thus causing them to stretch and to deform. spare Impregnation is possible.

[0200] spare The impregnation can in particular be carried out as described in US 2014 / 0005331 (A1), with the difference that the resin supply is carried out on two sides of the roving and that there is no surface contact, leaving one of the two surfaces free of any resin.

[0201] Advantageously, spare The impregnation step is carried out by melt passage at high speed, ie at a passing speed of said roving of at least 5 m / min, in particular more than 9 m / min.

[0202] Fluidized bed: spare The impregnation process may be carried out in a fluidized bed.

[0203] An exemplary unit for carrying out a manufacturing method without a heating step using at least one support part is described in international application WO2015 / 121583.

[0204] This system is spare The use of a vessel with a fluidized bed for carrying out the impregnation process has been described and can be used in the context of the present invention.

[0205] Advantageously, the vessel with the fluidized bed is provided with at least one support part (E') (Fig. 1) which may be a compression roller (Fig. 2).

[0206] The support portion (E') must be understood to mean any system on which the rovings can move in the tank. The support portion (E') can have any shape as long as the rovings can pass through it.

[0207] An example of the support part (E') is disclosed in detail in FIG. 1, without limiting the invention thereto.

[0208] The support portions (E) and (E') can be identical or different, whether in terms of material or shape and their characteristics (diameter, length, width, height, etc., depending on the shape).

[0209] However, the support part (E') does not heat and is not heated.

[0210] Fiber materials spare The impregnation step is carried out in a continuous process comprising a vessel (10) provided with at least one support part (E') and a fluidized bed (12) of said polymer matrix powder. spare This is done by passing one or more rovings through an impregnation device.

[0211] The polymer matrix or polymer powder is suspended in a gas G (e.g., air) introduced into the vessel and circulates from a hopper (11) to the vessel (10). Rovings are circulated in this fluidized bed (12).

[0212] The vessel can have any shape, in particular a cylinder or parallelepiped, in particular a rectangular parallelepiped, or a cube, advantageously a rectangular parallelepiped.

[0213] The vessel (10) can be an open vessel or a closed vessel.

[0214] In the event that the vessel is sealed, then the vessel is equipped with a sealing system so that the polymer matrix powder cannot leave the vessel.

[0215] Therefore, this spare The impregnation step is carried out by the dry route, ie the thermoplastic polymer matrix is ​​in powder form, particularly suspended in gas, particularly air, but not dispersible in solvents or water.

[0216] spare Each roving to be impregnated is unwound from a device equipped with a reel under a traction force exerted by a cylinder (not shown).

[0217] Each reel is equipped with a brake (not shown) to apply tension to each fiber roving. In this case, an alignment module allows the fiber rovings to be arranged parallel to each other. In this way, the fiber rovings cannot come into contact with each other, which makes it possible to avoid mechanical damage to the fibers due to friction against each other.

[0218] 2, the fiber roving or parallel fiber rovings then enter a vessel (10) comprising a fluidized bed (12) provided with a support (E'), in particular a compression roller (24). The ... spare After impregnation, the tank is left.

[0219] The expression "residence time in powder" means the time during which the rovings are in contact with said powder in the fluidized bed.

[0220] If the fibrous material, such as a glass or carbon fiber roving, has a sizing, an optional step of resizing may be performed before the fibrous material passes through the vessel.

[0221] Advantageously, the vessel used comprises a fluidized bed comprising a support, said spare The impregnation step is carried out while simultaneously stretching the roving(s) between the inlet and outlet of the vessel containing the fluidized bed.

[0222] The expression "vessel inlet" corresponds to a vertical tangent to the edge of the vessel containing the fluidized bed.

[0223] The expression "outlet of the vessel" corresponds to a vertical tangent to the other edge of the vessel comprising the fluidized bed.

[0224] The stretching consists in isolating as far as possible each fiber that constitutes the roving from the other fibers that surround it in the nearest space, which corresponds to stretching the roving in the transverse direction.

[0225] In other words, the lateral separation or width of the roving increases between the entrance to the vessel with the fluidized bed and the exit from the vessel with the fluidized bed, thus increasing the fibrous material spare This allows for improved impregnation.

[0226] therefore, spare The use of at least one support (E'), in particular a cylindrical compression roller, in the impregnation step, compared to the methods from the prior art, spare This allows for improved impregnation.

[0227] The expression "compression roller" means that the passing roving is partially or completely positioned on the surface of said compression roller, which causes said roving to stretch.

[0228] Advantageously, the at least one compression roller is cylindrical and the elongation of the roving between the inlet and the outlet of the fluidized bed vessel is between 1% and 1000%, preferably between 100% and 800%, preferably between 200% and 800%, preferably between 400% and 800%.

[0229] The draw ratio is equal to 100 times the ratio of the final width of the roving to the initial width of the roving.

[0230] The diameter of the at least one compression roller is between 3 mm and 500 mm, preferably between 10 mm and 100 mm, in particular between 20 mm and 60 mm.

[0231] Below 3 mm, the deformation of the fibers caused by the compression rollers is too great.

[0232] Advantageously, the compression roller is cylindrical, has no undulations and is in particular made of metal.

[0233] If the support part (E') is, according to the first variant, at least one compression roller, a single compression roller is present in the fluidized bed, spare Impregnation takes place at the angle α1 formed by the roving between the entrance of the compression roller and a vertical tangent to the compression roller.

[0234] The angle α1 formed by the roving between the entrance of the compression roller and a perpendicular tangent to the compression roller allows for the formation of a region where the powder is concentrated, thus spreading across a larger roving width with the simultaneous stretching of the roving by the compression roller. spare Impregnation, thus improving the technique of the background art spare A "corner effect" is created which allows for improved impregnation.

[0235] Throughout this description, all angle values ​​presented are expressed in absolute terms.

[0236] Advantageously, the angle α1 is comprised between 0 and 89°, preferably between 5° and 85°, preferably between 5° and 45°, preferably between 5° and 30°.

[0237] Nevertheless, angles α1 between 0 and 5° may cause the risk of mechanical stress, which may result in fiber breakage, while angles α1 between 85 and 89° do not generate sufficient mechanical forces to produce the "corner effect".

[0238] The value of the angle α1 is therefore equal to 0°, corresponding to vertical fibers. It is clear that the height of the cylindrical compression roller is adjustable, thus making it possible to position the fibers vertically.

[0239] Advantageously, the inlet edge of the tank (23a) is provided with rollers, in particular cylindrical and rotating, over which the rovings pass, thus spare Stretching is effected before impregnation.

[0240] The "corner effect" caused by the angle α1 is spare Although this enhances impregnation, the stretching of the roving achieved by using a compression roller also results in a coating of the other surface of the roving. spare It is clear that it is possible to impregnate the spare Impregnation is enhanced on the surface of one side of the roving(s) at an angle α1 formed by the roving(s) between the entrance to the at least one compression roller R1 and a perpendicular tangent to the compression roller R1, while stretching is also enhanced on the surface of the other side. spare Allows for impregnation.

[0241] The angle α1 is as defined above.

[0242] Advantageously, the particles of the thermoplastic polymer powder have a volume diameter D90 of between 30 and 500 μm, advantageously between 80 and 300 μm.

[0243] Advantageously, the particles of the thermoplastic polymer powder have a volume diameter D10 of between 5 and 200 μm, advantageously between 15 and 100 μm.

[0244] Advantageously, the volume diameter of the particles of the thermoplastic polymer powder is comprised in a ratio D90 / D10 of between 1.5 and 50, advantageously between 2 and 10.

[0245] Advantageously, the particles of the thermoplastic polymer powder have a mean volume diameter D50 of between 10 and 300 μm, in particular between 30 and 200 μm, especially between 45 and 200 μm.

[0246] The volume diameters of the particles (D10, D50 and D90) are defined by the standard ISO9276:2014.

[0247] "D50" corresponds to the mean diameter by volume, i.e., the particle size value that divides the tested particle population exactly in half.

[0248] "D90" corresponds to the value at 90% of the cumulative curve of the particle size distribution by volume.

[0249] "D10" corresponds to the size of 10% of the particle volume.

[0250] According to other variants, two, three or more rollers may be present in the fluidized bed.

[0251] Spraying with a spray gun: Fiber materials spare The impregnation process can also be carried out by continuous spraying, using a tank equipped with one or more nozzles or one or more guns that spray polymer powder onto the fibrous material at the entrance roller. spare This can be done by feeding one or more rovings into an apparatus for impregnation.

[0252] A polymer-based powder or polymer is sprayed onto the surface of the fibrous material in a bath, in particular by means of a nozzle or spray gun near the support of the compaction roller (at the entrance). The rovings are circulated in this bath.

[0253] A non-limiting example using a spray gun is shown in FIG.

[0254] All the features of the support, in particular the compression roller, the stretching and the angle α1 causing the corner effect, detailed for the fluidized bed are also valid for spraying with a spray gun.

[0255] According to other variants, there are two, three or more rollers, each of which has a spray gun.

[0256] Second step: spare Heating of the impregnated textile material and completion of impregnation therefore, spare The impregnation step can be carried out by any means provided with or without at least one support (E').

[0257] The presence of the support allows the roving to be stretched, spare The impregnation is improved. However, the presence of this support means that the heating system, provided with at least one support part (E), is unable to complete the impregnation. spare It is not essential as long as it is present after the impregnation step.

[0258] The expression "support part (E)" refers to any system over which rovings can pass. The support part (E) can have any shape as long as the rovings can pass over it. The support part can be fixed or rotating.

[0259] The heating system is any system that generates heat or any system that generates radiation, capable of heating the support part (E).

[0260] The heating system can be selected from infrared lamps, UV lamps, convection heating, microwave heating, laser heating and radio frequency (HF) heating.

[0261] The support part (E) is therefore electrically conductive and absorbs the radiation generated by the heat.

[0262] The expression "thermally conductive support part (E)" means that the support part (E) is made of a material that is able to absorb and conduct heat.

[0263] It can also be a heating system using radio frequency, microwave or laser.

[0264] In this case, the support part neither conducts heat nor absorbs heat-generated radiation.

[0265] The expression "non-thermally conductive support part (C)" means that the support part (E) is made of a material that is not able to absorb and conduct heat.

[0266] Said at least one support part (E) is located or provided in the environment of the heating system, ie is not outside the heating system.

[0267] Advantageously, said heating system is mounted on said at least one support part (E) and has a sufficient level so that the polymer present on the roving surface can melt but does not destroy said polymer.

[0268] Nevertheless, the heating system can either only comprise the at least one support part (E) or can also comprise a part of the roving outside the support system (E), the part of the roving being located in front of and / or behind the support system (E).

[0269] An illustration of the heating system and three supports (E) corresponding to R'1, R'2 and R'3 is shown in FIG. 4, but is in no way limited thereto.

[0270] It is clear that a second heating system can be present below the support, thus allowing uniform melting of the polymer on the two surfaces of the roving.

[0271] The heating system shown in Figure 4 is a horizontal system. However, the heating system can be vertically oriented, with the rovings still passing vertically through the support.

[0272] As a result, this heating step: spare During the impregnation step, it is possible to complete the impregnation of the rovings previously carried out and to obtain a uniform impregnation, in particular of the core.

[0273] The expression "uniform" means that the impregnation is uniform and that there is no drying out, i.e. no non-impregnated fibers, and conversely, no areas of pure resin without fibers over at least 95% of the volume of the tape made of impregnated fiber material.

[0274] Effectively, spare Whatever the system used for the impregnation process, in particular spare If the impregnation step is carried out by use of a supported part (E'), such as in a fluidized bed comprising at least one support, as described above, the first stretching is carried out during said step.

[0275] As the roving passes partially or entirely over the support portion (E'), a first stretching of the roping occurs at the compression roller corresponding to the support portion (E') due to the "corner effect", and as the roving passes partially or entirely over the support portion (E), a second stretching occurs at the compression roller corresponding to the support portion (E) during the heating step.

[0276] The heating system can be divided into two, thus consisting of two heating systems, namely a first heating system in front of said support part (E) and a second heating system comprising said support part. It is then very clear that the distance between the two heating systems is sufficient to ensure that the polymer remains in a molten state.

[0277] The two heating systems may be of the same or different nature and may have the same or different power outputs.

[0278] As the polymer melts on the surface of the roving, this second stretching is preceded by a contraction of the roving while the roving passes through a heating system before passing partially or completely over the support (E).

[0279] This second stretching combined with the melting of the polymer matrix due to the heating system and the contraction of the rovings results in spare It is possible to make the impregnation uniform, thus terminating the impregnation and thus having impregnation of the core, and to have a high fiber content by volume, in particular a constant value that is at least 70% of the volume of the tape, in particular at least 80% of the volume of the tape, in particular at least 90% of the volume of the tape, in particular at least 95% of the volume of the tape, and to reduce the porosity.

[0280] therefore, spare The roving, which has a width l1 before impregnation, spare After impregnation, the width l2>l1 is melted and the molten polymer is spareAfter the impregnated fiber material is shrunk, the width l3 <l2>It has l1.

[0281] After passing over the support portion, a second expansion of the fibrous material containing the molten polymer results in a material having a width l4 approximately equal to l2 and an average thickness of less than 100 μm.

[0282] This impregnated fibrous material then consists of a tape in the form of a strip of uncalibrated average width and thickness.

[0283] Advantageously, the inlet of the first compression roller R'1 and the outlet of the last compression roller R i The stretching ratio during the heating step between the outlet and the sheet is about 0 to 300%, particularly 0 to 50%.

[0284] The various stretching steps during the heating step, combined with the melting of the thermoplastic polymer and the shrinkage of the roving during said heating step, make it possible to produce, after the heating step, an impregnated fiber content of 45% to 65% by volume, preferably 50 to 60% by volume, in particular 54 to 60% (fiber contents that cannot be reached by conventional techniques by the melt route), in which the fiber level and distribution by volume over the entire length of said fibrous material is substantially equal to the average value on one side of the mid-plane of the fibrous material, thus obtaining in particular a single-layer fibrous material.

[0285] Below 45% fibres the reinforcement is not interesting in terms of mechanical properties.

[0286] Above 65%, the limit value of the method is reached and the mechanical properties are lost again.

[0287] It is quite clear that the average thickness e4 depends on the impregnated fiber content, the average thickness being in particular less than 100 μm for impregnated fiber contents between 45% and 65% by volume.

[0288] Without passing through the support (E) spare By heating the impregnated fibrous material it is possible to obtain tapes with an average thickness of more than 100 μm but less than 150 μm.

[0289] Advantageously, the porosity level in said impregnated fibrous material is less than 10%, in particular less than 5%, especially less than 2%.

[0290] Forming and calibration process: Obtaining thin tapes The steps of shaping the roving or said parallel rovings and calibrating said impregnated fibrous material, if performed, are performed after exiting the second heating system.

[0291] This step can be carried out directly after leaving the second heating system, in which case the speed of travel of the rovings is the same in the second and third heating systems, or it can be delayed, which means that the speed of travel of the rovings can be different between the second and third heating systems.

[0292] This step can be carried out according to one of the following embodiments: 1) Passing a strip over one or more supports (defined as (E)), at least one of which is notched (or grooved), wherein the average width of the strip is less than the notched (or grooved) support.

[0293] At least one of said supports is placed under a third heating system, in particular an IR, microwave, radio frequency or laser heating system, in particular an IR heating system having a power output (for each strip or stack of parallel strips) between 0.1 W and 10 kW, more preferably between 0.1 and 6 kW, more preferably between 0.1 and 3 kW, even more preferably between 0.6 and 3 kW, even more preferably between 0.6 and 1.8 kW.

[0294] Advantageously, said at least one notched roller (41) is located first and is outside the third heating system (45). Advantageously, the second notched support (44) is located at the outlet of the third heating system and outside said third heating system.

[0295] By passing over the unnotched supports (42) and (43), the strip is allowed to expand again to the width of the notched supports.

[0296] The diameter of the notched support(s) (41) and (44) is between 12 mm and 50 mm, in particular between 12 mm and 30 mm.

[0297] The diameter of the unnotched support(s) (42) and (43) is between 10 mm and 50 mm, in particular between 10 mm and 30 mm.

[0298] After passing under the third heating system, the strip is shaped to the width of the notched support at the outlet of the third heating system and passes through heated calenders (46) mounted in series and each equipped with a 1 kW IR system, the power delivered to which is variable, at the level of the heated calenders (46) outside the third heating system, to obtain a thin tape with a thickness of less than 100 μm.

[0299] FIG. 7 (after a single reel is used and has passed through the IR2 system) discloses an exemplary embodiment and is not limited to that embodiment.

[0300] Although the supports before IR3 and below IR3 are shown in Figure 7 at the same level, they can be at different heights, as can the second heating system. The notched supports can also have the same or different diameters as the unnotched supports.

[0301] 2) Passing the strip over one or more supports (as defined in (E)), at least one of which is notched (or grooved), the average width of the strip being greater than the notched (or grooved) support.

[0302] The support is placed under a third heating system, in particular an IR, microwave, radio frequency or laser heating system, in particular an IR heating system having a power output between 0.1 W and 10 kW, more preferably between 0.1 and 6 kW, more preferably between 0.1 and 3 kW, even more preferably between 0.6 and 3 kW, even more preferably between 0.6 and 1.8 kW. Advantageously, the at least one notched roller is positioned first.

[0303] Passing over the first notched edge, it is possible to reduce the width of the strip to less than the width of the notched groove. Advantageously, the second notched support is at the outlet of the third heating system, having a groove with a width greater than the width of the strip.

[0304] After passing under the third heating system, the strip is shaped to the width of the notched support at the outlet of the third heating system and passes through heated calendering machines mounted in series and each equipped with a 1 kW IR system, at the level of the heated calendering machines outside the third heating system, to obtain a thin tape with a thickness of less than 100 μm.

[0305] A calendering system with controlled pressure and roll gap as disclosed in WO2015 / 121583 can be used for both embodiments.

[0306] In order to gather the impregnated fibre material to the correct width, the support is in particular a fixed or rotating notched roller or may even be a counter-rotating roller, in particular a fixed roller.

[0307] The notched roller may also have rounded edges at the lateral contact points with the substrate to avoid damaging the fibers at the edges of the thin tape.

[0308] The expression "rounded edges" means that the bottom of the notch is concave or convex in shape.

[0309] The impregnated fibrous material then, after passing over a calendering system, consists of a tape in the form of a thin layer tape having a final average width of less than 14 mm.

[0310] Advantageously, the first embodiment of the molding and calibration steps is preferred.

[0311] The thin tape has an average thickness of less than 100 μm when the content of impregnated fibers is between 45% and 65% by volume.

[0312] Advantageously, said thin tape has a final average width of less than 14 and an average thickness of between 10 μm and 100 μm, for a content of impregnated fibers of between 45% and 65% by volume.

[0313] This therefore makes it possible to work at high travel speeds and thus reduce production costs.

[0314] Advantageously, the process according to the invention is carried out at a speed of at least 10 m / min, in particular at least 20 m / min, preferably at least 30 m / min.

[0315] Lamination and / or bonding processes Several embodiments are possible: 1) After the step of impregnating and obtaining the strips (tapes) disclosed above, or after the optional step of shaping and calibration in the thin tapes (tapes) defined above, a step of laminating and / or joining at least two tapes can be carried out, said N tapes at least partially overlapping.

[0316] This step can be performed in several embodiments: - In a first variant (Figure 7), said at least two strips are stacked and / or joined by passing over one or more supports (defined by (E)), at least one of which is notched (grooved).

[0317] At least one of said supports is placed under a third heating system, in particular an IR, microwave, radio frequency or laser heating system, in particular an IR heating system having a power output between 0.1 W and 10 kW, more preferably between 0.1 and 6 kW, more preferably between 0.1 and 3 kW, even more preferably between 0.6 and 3 kW, even more preferably between 0.6 and 1.8 kW.

[0318] Advantageously, a first notched (grooved) support of the desired size allows stacking and / or joining to the desired size outside the third heating system.

[0319] The strips, now laminated and / or bonded to the desired dimensions, are then passed over at least one unnotched support under said third heating system and then over a second notched support also under said third heating system.

[0320] Advantageously, two unnotched supports are present below said third heating system.

[0321] After passing under the third heating system, at the outlet of the third heating system the shaped strip is laminated and / or bonded up to the width of the notched support, and when it passes at the level of the heated calendering machine outside the third heating system, a web is obtained, which is mounted in series and each equipped with a 1 kW IR system with variable power (as a percentage of the maximum power),

[0322] In a second variant, the first notched roller of the first variant is also placed under a third heating system.

[0323] - in a third variant, said at least two strips pass over at least one support, possibly notched, provided with a heating system, to obtain a web, and then pass through a heated calender mounted in series, each equipped with a 1 kW IR system with variable power (as a percentage of the maximum power), at the level of the heated calender outside the third heating system.

[0324] The notched or unnotched supports used in the first, second and third variants have the following characteristics: The diameter of the notched support(s) (41) and (44) is between 12 mm and 50 mm, in particular between 12 mm and 30 mm.

[0325] The diameter of the unnotched support(s) (42) and (43) is between 10 mm and 50 mm, in particular between 10 mm and 30 mm.

[0326] - in a fourth variant, said at least two strips are heated by at least one heating system to obtain a web, which is then passed through a heated calender equipped with 1 kW IR systems mounted in series and each with variable power (as a percentage of the maximum power), at the level of the heated calender outside the third heating system.

[0327] In this embodiment, there is no support in the heating system.

[0328] - in a fifth variant, said at least two strips are heated to obtain a web and then passed through a heated calendering machine with warm drawing plates mounted in series, each equipped with a 1 kW IR system with variable power (as a percentage of the maximum power), at the level of the heated calendering machine outside the third heating system.

[0329] In this embodiment, there is no support in the heating system.

[0330] 2) The step of laminating and / or joining at least two strips is carried out under IR2 during the impregnation step to obtain the strips defined above.

[0331] Said at least two stacked and / or joined strips are then subjected to one of the five variants of the first embodiment disclosed above.

[0332] Generally, the heating system, with or without a support, is at a temperature above the Tm of the polymer, and the heated calenders mounted in series are at a temperature between the Tg and Tm of the polymer, advantageously between Tg + 50°C and Tg + 80°C, as determined by ISO 11357-2:2013.

[0333] Advantageous embodiments of the present invention Advantageously, the fiber material is chosen from carbon fibers and glass fibers.

[0334] Advantageously, the fibrous material is carbon fibre and each individual tape comprises several carbon fibres chosen from m×12,000 fibres, n×24,000 fibres and p×50,000 fibres, m being between 1 and 40, in particular between 1 and 4, n being between 1 and 20 and p being between 1 and 10, in particular 1.

[0335] Advantageously, the thermoplastic polymer used to impregnate the carbon fibers is a semi-aromatic polyamide.

[0336] Advantageously, the thermoplastic polymer used to impregnate the carbon fibers is a semi-aromatic polyamide chosen from PA MPMDT / 6T, PA PA11 / 10T, PA11 / BACT, PA11 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T, PA11 / BACT / 6T, PA11 / MPMDT / 10T, PA11 / BACT / 10T, PA11 / MXDT / 10T, PEEK, PEKK and PEI, or mixtures thereof.

[0337] Advantageously, the fibrous material is glass fibre and the basis weight for the glass fibre is greater than or equal to 1,200 Tex, in particular greater than or equal to 2,400 Tex, greater than or equal to 4,800 Tex.

[0338] Advantageously, the thermoplastic polymer used to impregnate the glass fibres is a semi-aromatic polyamide.

[0339] Advantageously, the thermoplastic polymer used to impregnate the glass fibres is a semi-aromatic polyamide chosen from PA MPMDT / 6T, PA PA11 / 10T, PA11 / BACT, PA11 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T, PA11 / BACT / 6T, PA11 / MPMDT / 10T, PA11 / BACT / 10T, PA11 / MXDT / 10T, PEEK, PEKK and PEI, or mixtures thereof.

[0340] Advantageously, of carbon fiber based fiber material spare The impregnation is carried out in a fluidized bed, followed by a step of heating to terminate the impregnation, to obtain an impregnated fibrous material consisting of a tape in the form of a strip having an average thickness of less than 100 μm, in particular between 10 μm and 100 μm, said heating step immediately followed by spare This is followed by an impregnation step.

[0341] Advantageously, the thermoplastic polymer constituting the tape in strip form used to impregnate the carbon fibres is a semi-aromatic polyamide.

[0342] Advantageously, the thermoplastic polymer constituting the tape in strip form used to impregnate the carbon fibres is a semi-aromatic polyamide chosen from PA MPMDT / 6T, PA PA11 / 10T, PA11 / BACT, PA11 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T, PA11 / BACT / 6T, PA11 / MPMDT / 10T, PA11 / BACT / 10T, PA11 / MXDT / 10T, PEEK, PEKK and PEI, or mixtures thereof.

[0343] Advantageously, the lamination and / or joining of N tapes of fibrous material in the form of strips, which can be at least partially overlapping, is carried out by heating said strips with at least one heating system, then passing said strips over at least one notched support provided with a heating system and then over a heated calender.

[0344] Advantageously, of carbon fiber based fiber material spare The impregnation is carried out in a fluidized bed, followed by a heating step, a step of terminating the impregnation, and a step of shaping and calibrating, to obtain an impregnated fibrous material consisting of a tape in the form of a thin tape having an average thickness of less than 100 μm, in particular between 10 μm and 100 μm, said heating step immediately followed by spare This is followed by an impregnation step.

[0345] Advantageously, the lamination and / or joining of N tapes of fibrous material in the form of thin tapes, which can be at least partially overlapping, is carried out by heating said tapes with at least one heating system, then passing said tapes over at least one notched support provided with a heating system and then over a heated calender.

[0346] Advantageously, the thermoplastic polymer constituting the tape in the form of a thin tape used to impregnate the carbon fibres is a semi-aromatic polyamide.

[0347] Advantageously, the thermoplastic polymer constituting the tape in the form of a thin tape used to impregnate the carbon fibers is a semi-aromatic polyamide chosen from PA MPMDT / 6T, PA PA11 / 10T, PA11 / BACT, PA11 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T, PA11 / BACT / 6T, PA11 / MPMDT / 10T, PA11 / BACT / 10T, PA11 / MXDT / 10T, PEEK, PEKK and PEI, or mixtures thereof.

[0348] Advantageously, of glass fiber based fibrous material spare The impregnation is carried out in a fluidized bed, followed by a step of heating to terminate the impregnation, to obtain an impregnated fibrous material consisting of a tape in the form of a strip having an average thickness of less than 100 μm, in particular between 10 μm and 100 μm, said heating step immediately followed by spare This is followed by an impregnation step.

[0349] Advantageously, the thermoplastic polymer constituting the tape in strip form used to impregnate the glass fibres is a semi-aromatic polyamide.

[0350] Advantageously, the thermoplastic polymer constituting the tape in strip form used to impregnate the glass fibres is a semi-aromatic polyamide chosen from PA MPMDT / 6T, PA PA11 / 10T, PA11 / BACT, PA11 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T, PA11 / BACT / 6T, PA11 / MPMDT / 10T, PA11 / BACT / 10T, PA11 / MXDT / 10T, PEEK, PEKK and PEI, or mixtures thereof.

[0351] Advantageously, the lamination and / or joining of N tapes of fibrous material in the form of strips, which may be at least partially overlapping, is carried out by heating said strips by means of at least one heating system, then passing said strips over at least one support provided with a heating system and then over a heated calender.

[0352] Advantageously, of glass fiber based fibrous material spare The impregnation is carried out in a fluidized bed, followed by a step of heating to terminate the impregnation, to obtain an impregnated fibrous material consisting of a tape in the form of a thin tape having an average thickness of less than 100 μm, in particular between 10 μm and 100 μm, said heating step immediately followed by spare This is followed by an impregnation step.

[0353] Advantageously, the thermoplastic polymer constituting the tape in the form of a thin tape used to impregnate the glass fibres is a semi-aromatic polyamide.

[0354] Advantageously, the thermoplastic polymer constituting the tape in the form of a thin tape used to impregnate the glass fibres is a semi-aromatic polyamide chosen from PA MPMDT / 6T, PA PA11 / 10T, PA11 / BACT, PA11 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T, PA BACT / 10T, PA BACT / 6T, PA BACT / 10T / 6T, PA11 / BACT / 6T, PA11 / MPMDT / 10T, PA11 / BACT / 10T, PA11 / MXDT / 10T, PEEK, PEKK and PEI, or mixtures thereof.

[0355] Advantageously, the lamination and / or joining of N tapes of fibrous material in the form of thin tapes, which can be at least partially overlapping, is carried out by heating said tapes with at least one heating system, then passing said tapes over at least one support provided with a heating system and then over a heated calender.

[0356] 1 shows a vessel (10) with a fluidized bed (12) with supports, the height of which (22) is adjustable. The inlet edge of the vessel is equipped with rotating rollers 23a, over which the rovings 21a pass, and the outlet edge of the vessel is equipped with rotating rollers 23b, over which the rovings 21b pass.

[0357] FIG. 2 describes an embodiment using a vessel (10) with a single compression roller, fluidized bed (12), in which there is a single cylindrical compression roller (24), exhibiting an angle α1.

[0358] The arrows on the fibers indicate the direction of fiber passage.

[0359] FIG. 3 shows an embodiment using a single compression roller, a vessel (30) with a spray gun (31) for spraying powder (32), in which there is a single cylindrical compression roller (33) and which exhibits an angle α″1.

[0360] The arrows on the fibers indicate the direction of fiber passage.

[0361] Figure 4 shows spare 1 shows a schematic diagram of a single heating system for heating the impregnated fibrous material and the use of three rollers to terminate the impregnation.

[0362] FIG. 5 shows a photograph taken with an optical microscope of the cross section of a SGL, 50K carbon fiber roving impregnated with PA BACT / 10T polyamide powder with D50=108 μm (D90=198 μm and D10=48.3 μm) according to Example 1 and as disclosed in WO 2015 / 121583 (before calendering).

[0363] The method according to WO2015 / 121583 results in a fibrous material that is too thick (181 μm), lacks uniformity in some areas of the impregnated roving and also large pores, and poor distribution of the fibers.

[0364] The diameter of the fibers represents 7 μm.

[0365] FIG. 6 shows a photograph taken with an optical microscope of the cross section of a SGL, 50K carbon fiber roving impregnated with PA BACT / 10T polyamide powder (41 / 59 molar ratio) with D50=108 μm (D90=198 μm and D10=48.3 μm) according to Example 2 of the present invention (before calendering).

[0366] The diameter of the fibers represents 7 μm.

[0367] The resulting strip has an average thickness of less than 88 μm with a fiber content of 55% by volume.

[0368] FIG. 7 shows an embodiment (40) of the stacking of three strips (obtained in FIG. 6) formed to 12.7 mm to obtain a web of width 12.7 mm.

[0369] This embodiment involves passing three fibrous materials in parallel through a second heating system, then stacking the three strips at the level of a first notched support (41) (diameter 13 mm, grooves 12.7 mm) outside the infrared system (45 (IR3)), then two unnotched supports (42) and (43) (diameter 20 mm) and one notched support (44) (diameter 13 mm, grooves 12.7 mm), below an IR system (45) and heated calenders (46) mounted in series, each equipped with an IR system of 1 kW, the power of which is variable.

[0370] FIG. 8 shows a photograph taken with an optical microscope of the cross section of a Toray (T700 12k 31E) carbon fiber roving impregnated with PA11 / BACT polyamide powder (33 / 67 molar ratio) with D50=108 μm (D90=198 μm and D10=48.3 μm) according to Example 2 of the present invention (before calendering).

[0371] The diameter of the fibers represents 7 μm.

[0372] The resulting strip has an average thickness of less than 63 μm with a fiber content of 55% by volume.

[0373] FIG. 9 shows a photograph taken with an optical microscope of the cross section of a Toray (T700 12k 31E) carbon fiber roving impregnated with PA6I / 6T polyamide powder (45 / 55 molar ratio) with D50=136 μm (D90=225 μm and D10=75 μm) according to Example 3 of the present invention (before calendering).

[0374] The diameter of the fibers represents 7 μm.

[0375] The resulting strip has an average thickness of less than 63 μm with a fiber content of 55% by volume.

[0376] FIG. 10 shows a photograph taken with an optical microscope of the cross section of a carbon fiber roving (Toray T700 12k 31E carbon fiber) impregnated with PA MPMDT / 10T powder (41 / 59 molar ratio) with D50=157 μm (D90=301 μm and D10=58 μm) according to Example 4 of the present invention (before calendering).

[0377] The diameter of the fibers represents 7 μm.

[0378] The resulting strip has an average thickness of less than 63 μm with a fiber content of 55% by volume. [Example]

[0379] Example 1 Preparation of a 12.7 mm wide and 250 μm thick web Single-layer fiber material (SGL, 50K carbon fiber) impregnated with BACT / 10T (41 / 59 molar ratio) The following steps were performed: Four cylindrical and fixed rollers with a diameter of 8 cm are present upstream of the vessel with the fluidized bed over which the rovings move.

[0380] The rollers are spaced 54 cm apart (distance between the central axis of the first roller and the central axis of the last roller).

[0381] Fluidized bed spare Impregnation process - Cylindrical compression roller R1 in a trough (L=500mm, l=500mm, H=600mm), diameter 25mm, as shown in Figure 2 - 0.3 seconds dwell time on powder - Angle α1 is 25° - For BACT / 10T powder, D50 = 108 μm (D10 = 48.3 μm, D90 = 198 μm). - The rim of the tank is equipped with fixed rollers.

[0382] spare Finishing the heating and impregnation of the impregnated fiber material The heating system disclosed in FIG. 4 is used, but with eight fixed cylindrical rollers R'1 to R'8, each having a diameter of 8 mm.

[0383] The traveling speed of the roving is 10 m / min.

[0384] The infrared generator used has a total power of 25 kW, the height between the infrared generator and the upper roller is 4 cm, and the height between the infrared generator and the lower roller is 9 cm.

[0385] The angles α'1 to α'8 are all the same, 25°.

[0386] The height h is 20 mm.

[0387] The length l is 1000 mm.

[0388] The eight rollers are spaced 43 mm apart.

[0389] FIG. 6 shows the resulting impregnated fiber material (strip) with a thickness of 88 μm.

[0390] The resulting fibrous material is a single layer material, which has low porosity with impregnation uniformity and very good distribution of the fibers.

[0391] Lamination process Figure 7 details this process.

[0392] The three strips obtained in the previous step are stacked at the level of a first notched support (41) (diameter 13 mm, grooves 12.7 mm) outside the infrared system (45 (IR3)), then the three stacked strips are passed under the IR system (45) over two unnotched supports (42) and (43) (diameter 20 mm), then over a notched support (44) (diameter 13 mm, grooves 12.7 mm) and finally over heated calenders (46) mounted in series, each equipped with an IR system of 1 kW.

[0393] The resulting web has a width of 12.7 mm and a thickness of 250 μm.

[0394] Example 2 Preparation of a web with a width of 12.4 mm and a thickness of 189 μm Single-layer fiber material (Toray T700 12k 31E carbon fiber) impregnated with PA11 / BACT powder (33 / 67 molar ratio) with D50 = 114 μm (D10 = 56 μm, D90 = 199 μm). The preparation of the strips and their subsequent lamination used the same procedures as in Example 1. The notched support has a 12.4 mm groove.

[0395] The resulting web had a density of 194 g / m 2 The width is 12.4 mm and the thickness is 189 μm for a basis weight of carbon fiber.

[0396] Example 3 Preparation of a web with a width of 12.4 mm and a thickness of 189 μm Single-layer fiber material (Toray T700 12k 31E carbon fiber) impregnated with PA6I / 6T powder (45 / 55 molar ratio) with D50 = 136 μm (D90 = 225 μm, D10 = 75 μm). The preparation of the strips and their subsequent lamination used the same procedures as in Example 1. The notched support has a 12.4 mm groove.

[0397] The resulting web had a density of 194 g / m 2 The width is 12.4 mm and the thickness is 189 μm for a basis weight of carbon fiber.

[0398] Example 4 Preparation of a web with a width of 12.4 mm and a thickness of 189 μm Single-layer fiber material (Toray T700 12k 31E carbon fiber) impregnated with PA MPMDT / 10T powder (41 / 59 molar ratio) with D50 = 157 μm (D90 = 301 μm, D10 = 58 μm). The preparation of the strips and their subsequent lamination used the same procedures as in Example 1. The notched support has a 12.4 mm groove.

[0399] The resulting web had a density of 194 g / m 2 The width is 12.4 mm and the thickness is 189 μm for a basis weight of carbon fiber.

Claims

1. 1. A web of impregnated fibrous material comprising N individual tapes of fibrous material laminated and / or bonded to one another, the N individual tapes being adhered to one another and capable of at least partially overlapping, the individual tapes of fibrous material comprising continuous fibers impregnated with at least one thermoplastic polymer and optionally a chain extender, the web having a cross section perpendicular to the axis of the fibers of: ｔｈ In a cross section perpendicular to the fiber axis, represented as S, the surface area is substantially equal to the sum of the surfaces of each of the original individual tapes, and S ｔｈ is equal to N×l×Ep, where l represents the average width of the tapes and Ep represents the average thickness of the tapes, N is between 2 and 2,000, and the average thickness of each of the individual tapes is 150 μm or less, said at least one thermoplastic polymer has a number average molecular weight (Mn) in the range of 500 to 10,000, said at least one thermoplastic polymer is selected from polyamide, PEKK, PEI, and mixtures of PEKK and PEI, said polyamide being selected from aliphatic polyamides, cycloaliphatic polyamides, and semi-aromatic polyamides, and the porosity level in said web of impregnated fibrous material is less than 10%.

2. 1. A web of impregnated fibrous material comprising N individual tapes of fibrous material laminated and / or bonded to one another, the N individual tapes being adhered to one another and capable of at least partially overlapping, the individual tapes of fibrous material comprising continuous fibers impregnated with at least one thermoplastic polymer and optionally a chain extender, the web having a cross section perpendicular to the axis of the fibers of: ｔｈ In a cross section perpendicular to the fiber axis, represented as S, the surface area is substantially equal to the sum of the surfaces of each of the original individual tapes, and S ｔｈ 1. A web of impregnated fibrous material, wherein N is equal to N×l×Ep, where l represents the average width of the tapes and Ep represents the average thickness of the tapes, N is between 2 and 2,000, and the average thickness of each of the individual tapes is 150 μm or less, the at least one thermoplastic polymer has a number average molecular weight (Mn) in the range of 500 to 10,000, the at least one thermoplastic polymer is selected from polyaryletherketones (PAEK); polyaryletherketoneketones (PAEKK); aromatic polyetherimides (PEI); polyarylsulfones; polyarylsulfides; polyamides; PEBA, polyacrylates; polyolefins; and mixtures thereof, the polyamides being selected from aliphatic polyamides, cycloaliphatic polyamides, and semi-aromatic polyamides, and the porosity level in the web of impregnated fibrous material is less than 10%.

3. the web comprises Nl tapes across its width and Nep tapes across its thickness, 3. A web of impregnated fibrous material according to claim 1 or 2, characterized in that each individual tape comprises several carbon fibres selected from m x 12K fibres, n x 24K fibres, p x 48K, q x 50K fibres and w x 400K fibres, where m is between 1 and 40, n is between 1 and 20, q is between 1 and 10, p is between 1 and 10 and w is equal to 1.

4. The average thickness and average width of the N individual tapes are the same, and the average thickness of the web is but, ×er, is the average number of tapes of thickness, er is the average thickness of each individual tape, and but, × lr, 4. A web of impregnated fibrous material according to claim 3, characterized in that lr is the average number of tapes of width and lr is the average width of each of the individual tapes.

5. The average thickness and average width of the N individual tapes are the same, and the average thickness of the web is but, xer, is the average number of tapes of thickness, er is the average thickness of each individual tape, and but, × lr, 4. A web of impregnated fibrous material according to claim 3, characterized in that lr is the average number of tapes of width and lr is the average width of each of the individual tapes.

6. The average thickness and average width of the N individual tapes are the same, and the average thickness of the web is but, Larger than xer, is the average number of tapes of thickness, er is the average thickness of each individual tape, and but, × larger than lr, 4. A web of impregnated fibrous material according to claim 3, characterized in that lr is the average number of tapes of width and lr is the average width of each of the individual tapes.

7. 7. A web of impregnated fibrous material according to any one of claims 3 to 6, characterized in that N tapes are stacked together, the number of width tapes Nl being equal to 1 and the number of thickness tapes Nep being between 2 and 2,000.

8. 7. A web of impregnated fibrous material according to claim 3, characterized in that N tapes are joined together, the number of thickness tapes Nep being equal to 1 and the number of width tapes Nl being between 2 and 2,000.

9. 7. A web of impregnated fibrous material according to any one of claims 3 to 6, characterized in that N tapes are stacked and bonded to one another.

10. 4. A web of impregnated fibrous material according to claim 3, characterized in that the N individual tapes have different average thicknesses and / or widths.

11. 11. A web of impregnated fibrous material according to any one of claims 1 to 10, characterized in that the thickness of the web of N tapes stacked and / or bonded to one another can vary over its width.

12. 12. A web of impregnated fibrous material according to any one of claims 1 to 11, characterized in that the thickness of the web of N tapes stacked and / or bonded to one another is constant over its entire width.

13. 13. A web of impregnated fibrous material according to any one of claims 1 to 12, characterized in that the volumetric fibre content is constant for at least 70% of the volume of each of the N tapes of fibrous material stacked and / or bonded together in the web, and that the N tapes can at least partially overlap.

14. 13. A web of fibrous material according to any one of claims 1 to 12, characterized in that the fibre content is between 45 and 65% by volume for each of the N tapes of fibrous material that are stacked and / or bonded to the web, and that the N tapes can at least partially overlap in the web of fibrous material.

15. 15. A web of impregnated fibrous material according to any one of claims 1 to 14, characterized in that the tape of fibrous material does not comprise a chain extender and the at least one thermoplastic polymer is an amorphous polymer, the glass transition temperature of which is Tg ≥ 80°C, or a semi-crystalline polymer, the melting temperature of which is Tm ≥ 150°C.

16. A web of impregnated fibrous material according to any one of the preceding claims, characterized in that the at least one thermoplastic polymer has a number average molecular weight (Mn) in the range of 4,000 to 8,000.

17. 17. The web of fibrous material of claim 16, characterized in that the at least one partially polymerized reactive thermoplastic prepolymer comprises at least one reactive prepolymer having two terminal functional groups X′ and Y′, respectively, on the same chain, which react together by condensation, X′ and Y′ being amine and carboxyl, or carboxy and amine, respectively.

18. 17. The web of fibrous material of claim 16, wherein the at least one partially polymerized reactive thermoplastic prepolymer comprises at least two polyamide prepolymers reacted together, each having two identical terminal functional groups X' or Y', wherein the functional group X' of one prepolymer can react only with the functional group Y' of the other prepolymer.

19. The at least one reactive thermoplastic prepolymer partially polymerized with the chain extender is selected from the group consisting of: a1) —NH ２ , -CO ２ at least one reactive thermoplastic prepolymer having n reactive terminal functional groups X selected from H and —OH, where n is 1 to 3; a2) at least one chain extender Y-A'-Y, where A' is a hydrocarbon disubstituent bearing two identical terminal reactive functional groups Y reactive by polyaddition with at least one functional group X' of said prepolymer a1).

20. 20. A web of fibrous material according to any one of the preceding claims, characterized in that the N tapes of fibrous material consist of the same at least one thermoplastic polymer.

21. The aliphatic polyamide is selected from polyamide 6 (PA-6), polyamide 11 (PA-11), polyamide 12 (PA-12), polyamide 66 (PA-66), polyamide 46 (PA-46), polyamide 610 (PA-610), polyamide 612 (PA-612), polyamide 1010 (PA-1010), polyamide 1012 (PA-1012), polyamide 11 / 1010, polyamide 12 / 1010, or mixtures thereof or copolyamides and block copolymers thereof, and the semi-aromatic polyamide is a semi-aromatic polyamide which may be modified with urea units, or a semi-aromatic polyamide of formula A / XT, where A is a unit derived from an amino acid, a unit derived from a lactam, and a unit derived from a diamine. (Cb diacids) [where "a" represents the number of carbon atoms in the diamine, "b" represents the number of carbon atoms in the diacid, and "a" and "b" are each between 4 and 36], the units (Ca diamines) are selected from aliphatic diamines, linear or branched alicyclic diamines, and alkylaromatic diamines, and the units (Cb diacids) are selected from aliphatic diacids, linear or branched diacids, alicyclic diacids, and aromatic diacids; 21. A web of fibrous material according to any one of claims 1 to 20, characterized in that X. T represents units resulting from the polycondensation of a Cx diamine and terephthalic acid, where x represents the number of carbon atoms in the Cx diamine and x is between 6 and 36.

22. 22. A web of fibrous material according to any one of claims 1 to 21, characterized in that the fibrous material comprises continuous fibres selected from carbon, glass, silicon carbide, basalt or basalt-based silica, natural fibres, or amorphous thermoplastic fibres having a Tg higher than the glass transition temperature Tg of the polymer or polymer blend, or semi-crystalline thermoplastic fibres having a Tm higher than the Tg of the polymer or polymer blend, or a mixture of two or more of said fibres, The web, wherein the polymer mixture is amorphous.

23. 22. A web of fibrous material according to any one of claims 1 to 21, characterized in that the fibrous material comprises continuous fibres selected from carbon, glass, silicon carbide, basalt or basalt-based silica, natural fibres, or amorphous thermoplastic fibres having a Tg higher than the Tm of the polymer or polymer blend, or semi-crystalline thermoplastic fibres having a Tm higher than the melting temperature Tm of the polymer or polymer blend, or a mixture of two or more of said fibres, The web wherein the polymer blend is semi-crystalline.

24. 24. A web of fibrous material according to any one of the preceding claims, characterized in that the thermoplastic polymer further comprises a carbon-based filler.

25. 25. A web of fibrous material according to any one of claims 1 to 24, characterized in that the thermoplastic polymer further comprises, as an additive, a liquid crystal polymer or a cyclic poly(butylene terephthalate), or a mixture containing said liquid crystal polymer or said cyclic poly(butylene terephthalate).

26. It consists of Nep tapes stacked together and Nl tapes joined together, and the number of tapes with a thickness of Nep ｊ 26. A web of fibrous material according to any one of claims 4 to 25, characterized in that N is between 1 and 4 and the number of tapes in width Nl is between 1 and 94.

27. 27. A web of fibrous material according to claim 26, characterized in that the number of thickness tapes Nep is selected from 2 and 4, and the number of width tapes Nl is 1.

28. 27. A web of fibrous material according to claim 26, characterized in that the number of thickness tapes Nep is 1 and the number of width tapes Nl is chosen from 24 and 32.

29. 27. A web of fibrous material according to claim 26, characterized in that the number of thickness tapes Nep is 2 and the number of width tapes Nl is selected from 46, 62 and 92.

30. 30. A web of fibrous material according to any one of claims 1 to 29, characterized in that the web has cross-sectional surface dimensions, represented by average width and average thickness, selected from the following, respectively: 300mm x 2mm; 200mm x 2mm, 150mm x 2mm; 100mm x 2mm; 596.9mm x 1mm; 393.7mm x 1mm; 292mm x 1mm; 200mm x 1mm; 150mm x 1mm; 100mm x 1mm; 15mm x 0.25mm, 15mm x 0.225mm, 14mm x 0.265mm, 14mm x 0.240mm, 12.7mm x 0.265mm, 12.7mm x 0.189mm, 596.9mm x 0.12mm; 393.7mm x 0.12mm; 292.1mm x 0.12mm.

31. 31. Use of a web of fibrous material as defined in any one of claims 1 to 30 for manufacturing a three-dimensional composite part by automated placement of said web by a robot.

32. 32. Use according to claim 31, characterized in that the production of the composite parts relates to the transport sector, oil and gas, gas storage, aviation equipment, ships and railways; renewable energy, energy storage devices, solar panels; thermal protection panels, sports and recreation, health and medicine, and electronics.

33. A three-dimensional composite part, characterized in that it is obtained from the use of at least one web of impregnated fibrous material as defined in any one of claims 1 to 30.

34. 31. A method for preparing a web of fibrous material as defined in any one of claims 1 to 30, comprising a step of stacking and / or bonding the tapes of fibrous material, wherein the N tapes can at least partially overlap.

35. The laminating and / or bonding process may be carried out using at least one of the following systems: 1) heating the tape with at least one heating system, then passing the tape over at least one support provided with a heating system, and then passing the tape over a heated calender; 2) passing the tape over at least one support provided with a heating system and then passing the tape over a heated calender; 3) heating the tape with at least one heating system and then passing the tape over a heated calender; 4) heating the tape with at least one heating system and then passing the tape through a warm drawing plate and over a heated calender; 35. The method of claim 34, wherein the method is performed by:

36. a previous step of heating the fibrous material pre-impregnated with the thermoplastic polymer and optionally with a chain extender to terminate the impregnation and obtain an impregnated fibrous material consisting of a tape in the form of a strip having an average thickness of less than or equal to 100 μm; Optionally, shaping and calibrating the rovings of the impregnated fibrous material or the parallel rovings to obtain an impregnated fibrous material consisting of a tape in the form of a thin tape having an average thickness of less than or equal to 100 μm, 36. The method of claim 34 or 35, further comprising:

37. 37. The method according to any one of claims 34 to 36, characterized in that it further comprises a previous step of pre-impregnating the fibrous material.

38. 38. The method of any one of claims 34 to 37, further comprising shaping the web by means of at least one notched calender, possibly a heated calender.

39. below: i) pre-impregnating a fibrous material to obtain a pre-impregnated fibrous material; ii) heating said pre-impregnated fibrous material and terminating the impregnation to obtain an impregnated fibrous material consisting of a tape in the form of a strip having an average thickness of less than or equal to 100 μm; iii) optionally shaping and calibrating the rovings of the impregnated fibrous material or the parallel rovings to obtain an impregnated fibrous material consisting of a tape in the form of a thin tape having an average thickness of less than or equal to 100 μm; iv) stacking and / or joining N tapes of fibrous material in the form of strips or thin tapes, said N tapes being able to at least partially overlap; v) shaping the web by at least one notched calender, optionally a heated calender; 39. The method of any one of claims 34 to 38, comprising:

40. 40. A method according to any one of claims 34 to 39, characterized in that it is carried out at a speed of at least 10 m / min.

41. 40. A method according to any one of claims 34 to 39, characterized in that it is carried out at a speed of at least 10 m / min.

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