Functionalized tapes for the manufacture of fiber-reinforced composite parts

Abstract

Functionalized tapes for the manufacture of fiber-reinforced composite parts A method for providing a functionalized veil or tape for the manufacture of fiber-reinforced composite parts, comprising depositing functional particles 12 in and / or on a veil or tape 11 by flowing a fluid 13 F through the veil or tape 11 to provide the functionalized veil or tape, wherein the veil or tape comprises reinforcing fibers and the fluid includes the functional particles.

Description

[Technical Field]

[0001] The present invention relates to a veil or tape comprising reinforcing fibers for producing fiber-reinforced composite parts, in particular to a functionalized veil or tape comprising reinforcing fibers for producing fiber-reinforced composite parts. [Background technology]

[0002] Automated layup of fiber-reinforced composites, for example by automated tape laying (ATL) and automated fiber placement (AFP), typically involves laying fiber tapes, fabrics, or tows onto a form, for example, using a robot or CNC machine. The tapes, fabrics, and tows may be binder-infused or resin-impregnated (also known as prepregs). The layup of fiber-reinforced composite parts can be accelerated by laying multiple courses simultaneously, laying multiple tapes, fabrics, or tows simultaneously, and / or increasing the width of the tapes, fabrics, or tows. ATL typically uses tapes having relatively wide widths of 2, 3, 6, 12, or 24 inches (nominal 51, 76, 152, 305, or 610 mm), while AFP typically uses tows (also known as ribbons) having relatively narrow widths of 1 / 8, 1 / 4, 1 / 2, or 1 inch (3.17, 6.35, 12.7, or 25.4 mm), although there is a movement to further increase tow widths up to 1.5 inches (38.1 mm). The choice of tape, fabric, or tow width is typically limited by the part curvature in two or three dimensions.

[0003] Functionalized veils or tapes (including functionally graded veils or tapes) may be used to transition between two different fiber-reinforced composite components with different properties, for example, different dielectric properties. By grading (also known as grading or tapering) the functional additives and / or functional layers, the properties can be varied across the width and / or along the length of the functional tape. For example, a conductive taper may be required to allow integration of a dielectric component (e.g., a radome) with a carbon fiber structural component of an airframe.

[0004] Conventional methods for providing functionalized veils or tapes containing reinforcing fibers for the manufacture of fiber-reinforced composite parts are relatively complex, expensive, and / or energy intensive. For example, conventional methods for providing functionally graded veils or tapes with resistive tapers rely on sputtering conductive particles onto the veil or tape and then integrating them into a ply layup.

[0005] Therefore, there is a need for improved production of functionalized veils or tapes comprising reinforcing fibers for the production of fiber-reinforced composite parts. Summary of the Invention

[0006] A first aspect provides a method for providing a functionalized veil or tape (more generally, a film) for the manufacture of a fiber reinforced composite part, the method comprising: depositing functional particles in and / or on the veil or tape by flowing a fluid through the veil or tape to provide a functionalized veil or tape; The veil or tape comprises reinforcing fibers; The fluid includes functional particles.

[0007] In this way, functionalized veils or tapes can be used to transition between two different fiber-reinforced composite components with different properties, e.g., different dielectric properties. For example, a conductive taper is needed to enable the integration of a dielectric component (e.g., a radome) with a carbon fiber structural component of an airframe. Other applications include EMI / RFI shielding, lightning strike protection, and tailored functionality. In contrast to conventional methods of providing functionalized veils or tapes containing reinforcing fibers for the manufacture of fiber-reinforced composite components, the method according to the first aspect is relatively simple, inexpensive, and / or less energy-intensive, since the functionalized veil or tape is provided by depositing functional particles in and / or on the veil or tape by flowing a fluid containing the functional particles through the veil or tape. In particular, the method according to the first aspect allows for a resistive taper in one single ply, thus reducing the complexity and features required at various points in a fiber-reinforced composite component, e.g., an airframe. For example, a non-uniform deposition of functional particles can be provided by depositing the functional particles non-uniformly in and / or on the veil or tape, such as by stepwise deposition, patterning, and / or masking of the functional particles, thereby providing graded or patterned properties, such as the electrical, thermal, magnetic, and / or structural properties of the veil or tape. In other words, such properties of the veil or tape can be tailored or customized for conductivity tapers, for example, to enable integration of dielectric components (e.g., radomes) with carbon fiber structural components of an airframe. For example, the method according to the first aspect allows for variable properties, such as conductivity, across a single reel of material, while the method may be varied in-line, allowing custom reels to be produced.

[0008] It should be understood that the fluid includes and / or is a carrier fluid for carrying the functional particles. Generally, the carrier fluid is inert and therefore does not react with the functional particles. Additionally and / or alternatively, the fluid includes and / or is a reactive fluid for reacting with (e.g., functionalizing) the functional particles and / or the reinforcing fibers, initiating or participating in a reaction between the functional particles and the reinforcing fibers to improve bonding or knotting therebetween. It should be understood that the veil or tape is permeable to the fluid but at most semi-permeable to the functional particles, thereby depositing at least a portion of the functional particles therein and / or thereon, e.g., on the reinforcing fibers and / or in the pores between them.

[0009] Veils are generally highly porous nonwoven membranes or sheets made from short, chopped reinforcing fibers and can be used as a surface layer on fiber-reinforced composite parts. Tapes are generally woven and / or knitted continuous fibers, or are provided by spreading one or more tows, for example. ATL typically uses tapes with relatively wide widths of 2, 3, 6, 12, or 24 inches (nominal widths of 51, 76, 152, 305, or 610 mm), while AFP typically uses tows (also known as ribbons) with relatively narrow widths of 1 / 8, 1 / 4, 1 / 2, or 1 inch (3.17, 6.35, 12.7, or 25.4 mm), although there is a movement to further increase the tow width up to 1.5 inches (38.1 mm). Sheets are generally nonwoven staple fibers or woven and / or knitted continuous fibers with relatively wide widths. Generally, a tow is a bundle (ie, not braided or woven) of continuous fibers.

[0010] In one example, the fluid includes and / or is a gas, such as air, or an inert gas, such as nitrogen, and / or a reactive gas, such as hydrogen, contained within a chamber. In this manner, the gas, including the functional particles dispersed or entrained therein, can be caused to flow through the veil or tape, for example, by pumping the gas therethrough.

[0011] In one example, the fluid comprises and / or is a liquid, e.g., an organic solvent such as acetone and / or propan-2-ol, and / or a polar and / or non-polar solvent such as contained in a tank. Non-polar solvents may be preferred to reduce and / or avoid water contamination of the veil or tape. In this manner, the liquid with the functional particles dispersed, entrained, or suspended therein may flow through the veil or tape, for example, by pumping the liquid therethrough.

[0012] In one example, flowing the fluid containing the functional particles through the veil or tape includes flowing the fluid containing the functional particles through the veil or tape using a fluidized bed.

[0013] It should be understood that the functional particles have the electrical, thermal, magnetic, and / or structural properties necessary to provide the desired respective properties of the pre-impregnated tape for the fiber-reinforced composite part. In one example, the functional particles comprise and / or are conductive particles, e.g., metallic particles such as Au, Ag, Ni, Cu, Al, etc., and / or non-metallic particles such as graphene, reduced graphene oxide, conductive oxides, etc. In one example, the functional particles include and / or are nanoparticles, microparticles, nanowires, nanosheets, flakes, etc.

[0014] In one example, the metal is a transition metal, for example, a first, second, or third row transition metal. In one example, the metal is Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, or Zn. In one example, the metal is Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, or Cd. In one example, the metal is Hf, Ta, W, Re, Os, Ir, Pt, Au, or Hg. In one example, the lattice is a lanthanide. In one example, the metal is La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, or Lu. In one example, the metal is an actinide. In one example, the metal is Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, or Es.

[0015] Generally, the functional particles comprise a metal, e.g., a pure or unalloyed metal or an alloy thereof, and may comprise any metal suitable for fusing by melting. Generally, the functional particles comprise a metal, e.g., a pure metal or an alloy, and may comprise any metal from particles, e.g., powder particles, and may be produced by atomization.

[0016] These functional particles can be created by atomization, such as gas atomization, water atomization, or other processes known in the art.

[0017] In one example, the functional particles comprise inorganic compounds. Inorganic compounds, such as ceramics comprising functional metals, can comprise, for example, oxides, silicates, sulfides, sulfates, halides, carbonates, phosphates, nitrides, borides, and hydroxides of the metal. These inorganic compounds can also include a second such metal, for example, a mixed oxide, such as a mixture of barium titanate and strontium titanate, such as (Ba,Sr)TiO. Functional particles include TCP (tricalcium phosphate), MCP (monocalcium phosphate), DCP (dicalcium phosphate), tetracalcium phosphate, hydroxyapatite, alpha-TCP, beta-TCP, titanium oxide (phytania), aluminum oxide (alumina), zirconium oxide (zirconia), yttrium oxide (yttria), yttria-stabilized zirconia, indium oxide, indium tin oxide, boron nitride, silicon carbide, boron carbide, tungsten carbide, beryllium oxide, zeolite, cerium oxide (ceria), tungsten disilicide, sodium silicate, platinum silicate, The coating may comprise zirconium nitride, tungsten nitride, vanadium nitride, tantalum nitride, niobium nitride, silicon boride, barium titanate, lead zirconate titanate, zinc oxide, potassium niobate, lithium niobate, sodium tungstate, sodium chloride, sodium nitrate, potassium nitrate, potassium chloride, magnesium chloride, calcium chloride, calcium nitrate, magnesium nitrate, strontium oxide, strontium phosphate, strontium titanate, calcium sulfate, barium sulfate, calcium carbonate, sodium carbonate and / or sodium fluoride, or mixtures thereof.

[0018] Preferably, the functional particles comprise a transition metal and / or an oxide thereof.

[0019] The functional particles can have regular shapes, such as spherical, cubic, or rod-like, and / or irregular shapes (also known as morphologies), such as spheroidal, flaky, or granular.

[0020] The inventors have determined that the size of the functional particles, e.g., diameter (or largest dimension of the aggregate), can affect their dispersion in the fluid and / or in the veil or tape and / or on the veil or tape. Non-uniform dispersion in the fluid can result in undesirable inhomogeneity in the functionalized veil or tape. Such undesirable inhomogeneity in the functionalized veil or tape can make the functionalized veil or tape unsuitable. Relatively small particles can adversely affect viscosity. Relatively large particles can result in clogging.

[0021] At least 50% by weight of the functional particles may have a diameter of at most 100 nm. In the case of regular shapes, the diameter may refer, for example, to the diameter of a sphere or rod, or the side of a rectangular prism. The diameter may also refer to the length of a rod. In the case of irregular shapes, the diameter may refer, for example, to the largest dimension of the particle. Again, particle size distribution may be measured by using light scattering measurement of particles in an instrument such as a Malvern Mastersizer 3000 configured to measure particle sizes from 10 nm to 3500 micrometers, where the particles are wet dispersed in a suitable carrier liquid (with an appropriate dispersant compatible with the particle surface chemistry and the liquid chemistry) according to the instrument manufacturer's instructions and assuming the particles are of uniform density.

[0022] In one example, the additive particles comprise and / or are nanoparticles and have a diameter in the range of 1 nm to 100 nm, preferably in the range of 10 nm to 90 nm, more preferably in the range of 15 nm to 85 nm, and most preferably in the range of 25 nm to 75 nm, such as 50 nm. In one example, the additive particles comprise and / or are nanoparticles and at least 50% by weight of the nanoparticles have a diameter in the range of 1 nm to 100 nm, preferably in the range of 10 nm to 90 nm, more preferably in the range of 15 nm to 85 nm, and most preferably in the range of 25 nm to 75 nm, such as 50 nm. In one example, the additive particles comprise and / or are nanoparticles and at least 90% by weight of the nanoparticles have a diameter in the range of 1 nm to 100 nm, preferably in the range of 10 nm to 90 nm, more preferably in the range of 15 nm to 85 nm, and most preferably in the range of 25 nm to 75 nm, such as 50 nm. In one example, the additive particles comprise and / or are nanoparticles, wherein at least 95% by weight of the nanoparticles have a diameter in the range of 1 to 100 nm, preferably in the range of 10 to 90 nm, more preferably in the range of 15 to 85 nm, and most preferably in the range of 25 to 75 nm, e.g., 50 nm. In one example, the additive particles comprise and / or are nanoparticles, wherein at least 99% by weight of the nanoparticles have a diameter in the range of 1 to 100 nm, preferably in the range of 10 to 90 nm, more preferably in the range of 15 to 85 nm, and most preferably in the range of 25 to 75 nm, e.g., 50 nm.

[0023] Particles of these sizes may be referred to as nanoparticles. Generally, nanoparticles tend to aggregate to reduce surface energy. Agglomerates are collections of a variable number of particles, and the aggregates may vary, for example, in the number and / or shape of the particles. Nanopowders are solid powders of nanoparticles, often containing micron-sized nanoparticle aggregates. These aggregates can be redispersed (at least to some extent) in the solid state, for example, using sonication. Nanoparticle dispersions are suspensions of nanoparticles in a liquid carrier, such as water or an organic solvent / organic matrix. Agglomeration may depend, for example, on temperature, pressure, pH, and / or viscosity. Particle aggregation can result in uneven dispersion of the particles in the fluid. Therefore, the appropriate particle size may also be a balance between reducing agglomeration and avoiding clogging during use, all in order to achieve uniform dispersion and the desired distribution on and / or within the functionalized veil or tape. Furthermore, the morphology of the particles (nanopowder or suspension) can affect dispersion in the fluid.

[0024] In one example, the additive particles include and / or are particulates and have a diameter in the range of 10 μm to 1000 μm, preferably 100 μm to 900 μm, more preferably 150 μm to 850 μm, and most preferably 250 μm to 750 μm, such as 500 μm. In one example, the additive particles include and / or are particulates and at least 50% by weight of the particulates have a diameter in the range of 10 μm to 1000 μm, preferably 100 μm to 900 μm, more preferably 150 μm to 850 μm, and most preferably 250 μm to 750 μm, such as 500 μm. In one example, the additive particles comprise and / or are fine particles, wherein at least 90% by weight of the fine particles have a diameter in the range of 10 μm to 1000 μm, preferably in the range of 100 μm to 900 μm, more preferably in the range of 150 μm to 850 μm, and most preferably in the range of 250 μm to 750 μm, such as 500 μm. In one example, the additive particles comprise and / or are fine particles, wherein at least 95% by weight of the fine particles have a diameter in the range of 10 μm to 1000 μm, preferably in the range of 100 μm to 900 μm, more preferably in the range of 150 μm to 850 μm, and most preferably in the range of 250 μm to 750 μm, such as 500 μm. In one example, the additive particles comprise and / or are microparticles, at least 99% by weight of the microparticles having a diameter in the range of 10 μm to 1000 μm, preferably in the range of 100 μm to 900 μm, more preferably in the range of 150 μm to 850 μm, and most preferably in the range of 250 μm to 750 μm, for example 500 μm.

[0025] In one example, the additive particles include and / or are nanoparticles and microparticles, as described above. In one example, the additive particles comprise microparticles in the range of 1% to 99% by weight of the particles, preferably in the range of 10% to 90% by weight, and more preferably in the range of 25% to 75% by weight, and nanoparticles, e.g., the balance nanoparticles, in the range of 99% to 1% by weight of the particles, preferably in the range of 90% to 10% by weight, and more preferably in the range of 75% to 25% by weight. In one example, the additive particles consist of nanoparticles and microparticles, as described above.

[0026] It should be understood that the reinforcing fibers provide a substrate for the functional particles and may be the same as or different from the reinforcing particles of the fiber-reinforced composite component. It should be understood that the veil includes and / or is a nonwoven sheet comprising unoriented, typically chopped, reinforcing fibers having a relatively lower specific mass (i.e., mass per unit area) and / or a relatively thinner thickness than the tape. In one example, the reinforcing fibers include and / or are electrically insulating reinforcing fibers. In a preferred embodiment, the reinforcing fibers include and / or are electrically insulating reinforcing fibers, and the functional particles include and / or are electrically conductive particles. In this manner, the electrical properties of the veil or tape may be stepped (e.g., tapered) or patterned, for example, across its width and / or along its length, to transition between fiber-reinforced composite components having different properties, e.g., different dielectric properties as described above.

[0027] In one example, the reinforcing fibers include and / or are electrically conductive reinforcing fibers. In a preferred embodiment, the reinforcing fibers include and / or are electrically conductive reinforcing fibers, and the functional particles include and / or are electrically insulating particles. In this manner, the electrical properties of the veil or tape may be stepped (e.g., tapered) or patterned, for example, across its width and / or along its length, to transition between fiber-reinforced composite components having different properties, e.g., having different dielectric properties as described above.

[0028] In one example, the reinforcing fibers comprise non-metallic fibers, e.g., glass fibers such as A-glass, E-glass, E-CR-glass, C-glass, D-glass, R-glass, S-glass, S-2-glass, and HS-glass; aerospace-grade or industrial-grade carbon fibers such as IM2A, IM2C, IM5, IM6, IM7, IM8, IM9, IM10, AS4, AS4A, AS4C, AS4D, AS7, HM50, and HM63; aramid fibers such as Kevlar®, Nomex®, and Technora®; ultra-high molecular weight polyethylene (UHMwPE) fibers such as Dyneema®; basalt fibers such as Basfiber® or Wiking® Super B; and / or mixtures thereof. In one example, the reinforcing fibers comprise metal and / or alloy fibers, e.g., titanium, aluminum, and / or copper and / or alloys thereof; stainless steel fibers; and / or mixtures thereof. In one example, the reinforcing fibers comprise a mixture of non-metallic and metallic fibers.

[0029] In one example, the reinforcing fibers have a diameter in the range of 2 μm to 100 μm, preferably in the range of 4 μm to 50 μm, more preferably in the range of 5 μm to 20 μm, and most preferably in the range of 6 μm to 10 μm, for example, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm. Typically, suitable carbon fibers have a diameter in the range of 5 μm to 10 μm, and suitable glass fibers have a diameter in the range of 4 μm to 20 μm.

[0030] In one example, the volume fraction of reinforcing fibers, V f is in the range of 50% to 100% of the volume of the veil or tape, preferably in the range of 60% to 95%, for example 70%, 80% or 90%. In this way, a relatively high volume fraction V of reinforcing fibers in the veil or tape is achieved. f can be provided.

[0031] In one example, the volume fraction of reinforcing fibers, V fis in the range of 30% to 90% by volume of the fiber reinforced composite part, preferably in the range of 40% to 80% by volume, more preferably in the range of 40% to 70% by volume, for example 40%, 45%, 50%, 55%, 60%, 65% or 70% by volume. Generally, the volume fraction V of the matrix, e.g., the first polymer composition, is m is V f +V m = 1, and the volume fraction V of the reinforcing fibers, e.g., the first set of reinforcing fibers f Thus, a relatively high volume fraction of reinforcing fibers in a fiber-reinforced composite part, V f can be provided.

[0032] In one example, the tape comprises aligned and / or continuous reinforcing fibers, e.g., woven and / or knitted continuous fibers. In one example, the reinforcing fibers have a length of at least 2 mm, preferably at least 10 cm, more preferably at least 1 meter, and most preferably at least 10 meters. It should be understood that the length of the reinforcing fibers is the total length of each reinforcing fiber. That is, the reinforcing fibers may comprise and / or be continuous fibers.

[0033] In one example, the veil comprises unaligned and / or discontinuous reinforcing fibers, e.g., short fibers, such as a mat thereof. In contrast to continuous fibers, short fibers typically have a length of less than 3 mm and tend to be randomly arranged or not perfectly aligned.

[0034] In one example, depositing functional particles in and / or on the veil or tape comprises depositing the functional particles non-uniformly in and / or on the veil or tape. In this manner, the deposition of the functional particles in and / or on the veil or tape is controlled. In this manner, the functional particles are deposited non-uniformly in and / or on the veil or tape, thereby controlling the properties of the veil or tape, as described above. It should be understood that non-uniformly depositing functional particles in and / or on a veil or tape provides a non-uniform distribution of deposited functional particles across the width and / or along the length of the veil or tape such that the content (i.e., concentration, level, amount) of deposited functional particles varies across the width and / or along the length of the veil or tape, e.g., by at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 or more times across the width and / or along the length of the veil or tape, e.g., varies according to a predetermined non-uniform distribution or pattern (i.e., controlled, as compared to random). In contrast, uniformly depositing functional particles in and / or on a veil or tape provides a uniform distribution of deposited functional particles across the width and / or along the length of the veil or tape such that the content (i.e., concentration, level, amount) of the deposited functional particles varies across the width and / or along the length of the veil or tape, for example, by a factor of at most 2, 1.75, 1.5, 1.25, 1.1, 1.05 or less across the width and / or along the length of the veil or tape.

[0035] In one example, non-uniformly depositing functional particles in and / or on the veil or tape comprises non-uniformly depositing functional particles in and / or on the veil or tape across its width and / or length. In this manner, the properties of the veil or tape may be graded (e.g., stepped or tapered, e.g., linear or non-linear) or patterned (e.g., periodic or non-periodic), for example, across its width and / or along its length, to transition between fiber-reinforced composite components having different properties, as discussed above.

[0036] In one example, depositing functional particles non-uniformly in and / or on a veil or tape comprises depositing functional particles in and / or on the periphery (i.e., edges) of the veil or tape, e.g., only in and / or on the periphery, e.g., for a printed circuit board (PCB).

[0037] In one example, depositing functional particles non-uniformly in and / or on the veil or tape comprises masking (also known as patterning) the veil or tape, for example, using a mask (also known as a pattern). This results in the deposition of functional particles corresponding to the mask. In one example, masking the veil or tape comprises placing the mask upstream of the veil or tape (i.e., with respect to the flowing fluid), for example, close to the veil or tape, facing the veil or tape, or in contact with the veil or tape. In this way, the fidelity of the correspondence of the deposited functional particles to the mask is improved. In one example, masking the veil or tape comprises placing the mask downstream of the veil or tape (i.e., with respect to the flowing fluid), for example, close to the veil or tape, facing the veil or tape, or in contact with the veil or tape. In this way, the gradation of the deposited functional particles relative to the mask is weakened, thereby resulting in a smooth (compared to abrupt) transition in the content of deposited functional particles on and / or in the veil or tape.

[0038] In one example, depositing the functional particles in and / or on the veil or tape comprises applying a magnetic field and / or an electric field while flowing a fluid containing the functional particles through the veil or tape. In this manner, the deposition of the functional particles in and / or on the veil or tape is further controlled. In one example, applying a magnetic field and / or an electric field while flowing a fluid containing the functional particles through the veil or tape comprises applying the magnetic field and / or an electric field parallel to or transverse to the flowing fluid. Additionally and / or alternatively, depositing the functional particles in and / or on the veil or tape comprises applying a magnetic field and / or an electric field without flowing fluid (e.g., in a stationary tank or chamber), whereby the functional particles are urged toward the veil or tape by the applied magnetic field and / or applied electric field and deposited on the veil or tape.

[0039] In one example, depositing functional particles in and / or on the veil or tape comprises depositing functional particles on the reinforcing fibers and / or within the pores therebetween.

[0040] In one example, the method comprises reacting functional particles. In this manner, functional particles are deposited in and / or on the veil or tape and then reacted. In one example, the method comprises functionalizing functional particles. In this manner, non-functional particles are deposited in and / or on the veil or tape and then functionalized. For example, metal oxide particles can be reduced to metal particles.

[0041] In one example, the method comprises dispersing and / or suspending functional particles in a fluid, such as a gas or a liquid, as described above.

[0042] In one example, flowing a fluid containing functional particles through a veil or tape comprising reinforcing fibers comprises applying a fluid pressure differential through the veil or tape (i.e., a pressure differential through the thickness of the veil or tape sufficient to cause the fluid to flow through the veil or tape, e.g., due to pumping and / or osmotic pressure differential), e.g., in a chamber or bath. In this manner, flowing the fluid containing functional particles through the veil or tape is prompted by the applied fluid pressure differential through the veil or tape. In one example, applying a fluid pressure differential through the veil or tape comprises pumping the fluid through the veil or tape, e.g., using a pump.

[0043] In one example, flowing a fluid containing functional particles through a veil or tape comprising reinforcing fibers comprises orienting the veil or tape relative to the flowing fluid, e.g., at an angle thereto, thus providing a non-uniform distribution of deposited functional particles across the width and / or along the length of the veil or tape.

[0044] In one example, for example, when the veil or tape is a prepreg, the reinforcing fibers are at least partially surrounded by the first polymer composition. This improves handling of the veil or tape. In one example, the veil or tape is a pre-impregnated veil or tape. In one example, the veil or tape is dry, i.e., not at least partially surrounded by the first polymer composition.

[0045] Generally, prepregs are "pre-impregnated" reinforcement fibers that already have a thermosetting polymer matrix material, such as an epoxy, or a thermoplastic resin matrix. The fibers can be in the form of a woven fabric, and the matrix is used to bond the fibers to each other and to other components during manufacturing. The thermosetting matrix is only partially cured to allow for easy handling, and this B-stage material requires low-temperature storage to prevent complete curing. Because heat promotes complete polymerization, B-stage prepregs are always stored in a refrigerated area. Thermoplastic matrices do not require such low-temperature storage. Therefore, composite structures built with prepregs often require ovens or autoclaves for curing. Prepregs, for example, allow for impregnation of fibers on a flat surface, followed by laying the impregnated fibers to provide the desired shape, which can otherwise be problematic to lay without a matrix.

[0046] The thermoplastic prepreg may be provided, for example, in the form of a unidirectional tape or in the form of a woven or sewn fabric.

[0047] In one example, the first polymer composition comprises a first thermoplastic selected from the group comprising acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), polycarbonate (PC), polyamide (PA), polystyrene (PS), high density polyethylene (HDPE), PC / ABS, polyethylene terephthalate (PETG), polyphenylsulfone (PPSU), high impact polystyrene (HIPS), polytetrafluoroethylene (PTFE), lignin, rubber, and / or polyaryletherketones (PAEK), such as polyetherketoneketone (PEKK), polyetheretherketone (PEEK), and polyetherimide (PEI). In one example, the first thermoplastic comprises, consists of, and / or is PEKK, PEEK, and / or PEI, preferably PEKK and / or PEEK, more preferably PEKK. Compared to PEEK, PEKK is more robust (i.e., less sensitive) to cooling rates, at least in part due to the wider range of allowable crystallinity.

[0048] In one example, the first polymer composition comprises a reactive thermoplastic resin, such as Elium®. Elium is a liquid monomer that can be processed like a thermoset, but upon reaction, is converted into a thermoplastic resin that can then be thermoformed, melted, and / or welded. Anionic polymerization of caprolactam (the monomer of polyamide-6, PA-6) is also suitable. Generally, reactive thermoplastic resins may be cured after application, for example, by heating and / or by using a catalyst included in the first polymer composition, thereby reacting its molecules to provide a thermoplastic with improved mechanical properties.

[0049] In one example, the first polymer composition includes a second thermoplastic (ie, a copolymer) as described above with respect to the first thermoplastic.

[0050] In one example, the first polymer composition comprises a thermosetting resin, such as an epoxy, benzoxazine, bismaleimide (BMI), polyimide, polyurethane, silicone, vinyl, amino, furan, phenolic and / or cyanate ester resin, and optionally a curing agent.

[0051] The selection of an appropriate first polymer composition for the reinforcing fibers is known.

[0052] In one example, the method comprises stretching, e.g., continuously, a porous / semi-permeable veil or tape across an angular pressure differential, whereby the forced / entrained movement of functional particles is non-uniformly distributed across the width of the veil or tape. This may be accomplished by setting the distance and / or location of a pump or vacuum source on one side of the veil or tape to induce stronger flow at specific locations along the width.

[0053] In one example, the method comprises varying and / or controlling the angle (i.e., orientation) at which the bale or tape is presented over a pump or vacuum source to utilize the pump direction and / or gravity to assist in distributing particles (particularly, but not limited to, colloids) toward the bottom end of the bale (relative to the flat portion). In one example, the angle (i.e., the angle between the bale or tape and the direction of fluid flow) is in the range of 5° to 85°, preferably in the range of 15° to 75°, more preferably in the range of 30° to 60°, e.g., 45°.

[0054] In both of these methods, the veil or tape is not uniform in its porosity / permeability (and has significant variations in pass-through size / aggregate pore size / channel width) and therefore behaves differently as a "filtration medium," so successive blockages of pores in the veil or tape can be utilized; this is useful for further passes of the process and / or for depositing particles (unblocked / undesired distribution) as the initially treated veil or tape, and the deposited particles can affect further deposition by changing pore characteristics (size, number - both of which affect flow) as well as through effects arising from the properties (or mere presence) of the deposited particles (i.e., for example, magnetic attraction, chemical reactions, viscosity effects such as skin formation or beading to affect surface finish). These effects can be utilized to further influence the particle distribution, for example, by applying a strong magnetic field over a specific area / edge, or exposing a portion of the veil or tape to a reactant (e.g., immersing the edge), to further change properties and / or function; this is a useful technique for reacting deposited products in situ, which would otherwise be a pathway for particles that are too large (or difficult to handle) to be embedded in the veil or tape.

[0055] The affected width can be adjusted by using a blocking plate in front of the bale or tape to block particle flow, or behind the bale or tape to reduce vacuum / negative flow draw through the bale or tape. Alternatively, a device (with appropriate / additional curtaining) can be passed over a portion of the bale or tape to create a narrow taper over the edge of the bale or tape, or when a machine that processes the entire size of the bale or tape is impractical; a large bale or tape disk can be gradient-applied when its edge is rotated through such a machine, or indeed, when the machine is sized from the center to the disk edge, increased travel speed at the edge can provide a more uniform coating where non-uniform deposition is desired.

[0056] In one example, the method comprises continuously dispersing, re-dispersing and / or agitating functional particles contained in the fluid, e.g., while flowing the fluid containing the functional particles through a veil or tape, e.g., by agitating using a mixer, e.g., by ultrasound, to maintain a dispersion, e.g., a uniform dispersion, of the functional particles in the fluid.

[0057] A second aspect provides an apparatus for providing a functionalized veil or tape comprising reinforcing fibers for the manufacture of fiber reinforced composite parts, the apparatus comprising: To provide a functionalized veil or tape, means are provided for depositing functional particles in and / or on a veil or tape comprising reinforcing fibers by flowing a fluid containing the functional particles through the veil or tape.

[0058] The functionalized veil or tape, reinforcing fibers, fiber reinforced composite part, deposit, functional particles and / or fluid may be as described in relation to the first embodiment.

[0059] In one example, the apparatus comprises a means for dispensing the dispersion onto one side of the veil or tape (such as a liquid / gas nozzle, hopper and / or electrostatically / magnetically charged or other means, e.g., resonant acoustic mixing agitator, etc.).

[0060] In one example, the device comprises means for creating a pressure differential through the thickness of the veil or tape by either pressurizing the dispensing side and subjecting the other side to a vacuum source or ambient pressure, at least two of the three being used to maintain the pressure differential and impart flow to the fluid.

[0061] A third aspect provides a functionalized veil or tape comprising reinforcing fibers having non-uniformly deposited functional particles therein and / or thereon, for example provided according to the method of the first aspect and / or using the apparatus according to the second aspect.

[0062] The functionalized veil or tape, reinforcing fibers, fiber reinforced composite part, deposit, functional particles and / or fluid may be as described in relation to the first embodiment.

[0063] A fourth aspect provides a method of manufacturing a fiber reinforced composite part, for example an aircraft composite part such as an airframe or part thereof, the method comprising: providing a first fiber reinforced composite component and providing a second fiber reinforced composite component, wherein the first fiber reinforced composite component and the second fiber reinforced composite component have different properties, such as electrical, thermal, magnetic and / or structural properties; Joining a first fiber reinforced composite component and a second fiber reinforced composite component; and transitioning between the first fiber reinforced composite component and the second fiber reinforced composite component, for example using a pre-impregnated tape provided according to the method of the first aspect and / or using an apparatus according to the second and / or third aspect.

[0064] It is known to provide a first fiber reinforced composite component and to provide a second fiber reinforced composite component, and it is generally known to join the first fiber reinforced composite component and the second fiber reinforced composite component.

[0065] In one example, joining the first fiber reinforced composite component and the second fiber reinforced composite component comprises, at least in part, joining the first fiber reinforced composite component and the second fiber reinforced composite component using a pre-impregnated tape.

[0066] A fifth aspect provides a fibre reinforced composite part, such as an aircraft composite part, for example an airframe or part thereof, comprising a functionalised veil or tape according to the third aspect.

[0067] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0068] [Figure 1] 1(a), (b), (c), and (d) schematically depict a method according to an exemplary embodiment. [Figure 2] 2(a), (b), (c), and (d) schematically depict the functional particle content of a functionalized veil or tape according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0069] 1(a) to 1(d) schematically depict a method according to an exemplary embodiment.

[0070] The method provides a functionalized veil or tape comprising reinforcing fibers for the manufacture of fiber-reinforced composite parts, the method comprising: To provide a functionalized veil or tape, the method comprises depositing functional particles 12 in and / or on a veil or tape 11 comprising reinforcing fibers (not shown) by flowing F a fluid 13 containing functional particles 12 through the veil or tape 11.

[0071] More specifically, as shown schematically in the exemplary embodiment depicted in FIGS. 1(a) through 1(d), a material (i.e., a fluid 13, specifically a liquid containing functional particles 12 in this example) is drawn through a veil or tape to create a deliberate spread of functional particles across the width of the veil or tape. By controlling the angle (i.e., orientation) at which the veil or tape is presented on the pump, the pump direction and / or gravity are utilized to help distribute particles (specifically, but not limited to, colloids) toward the bottom edge of the veil (relative to the flat portion). Additionally and / or alternatively, a device performing the same operation, such as a mask, may be brought over the veil or tape and maintained statically or dynamically moved during the method. Preferably, the mask includes a protrusion on a larger piece of the veil or tape (useful, for example, to apply a narrower, tapered width for grounding a circuit board, providing a visual appearance similar to a gold-plated border).

[0072] This process can be carried out by a combination of a means of distributing the dispersion on one side of the veil or tape (liquid / gas nozzles, hoppers and / or agitators, electrostatically / magnetically charged, etc.) and a means of creating a pressure difference through the thickness of the veil or tape by differentially pressurizing the dispensing side (liquid or vacuum pump on one side of the veil or tape and ambient pressure on the other side of the veil or tape to maintain the pressure difference and force flow through the media, etc.).

[0073] Uses of the functionalized veil or tape provided by the method according to the first aspect may include conductive distributions intended to reduce EM interference on substrates, including ground planes or ground edges integrated into PCB materials (e.g. FR4 PCB materials), in particular ground planes or ground edges where analog and digital circuits exist on the same substrate, Faraday cages / enclosures, etc.

[0074] Other civilian applications include coloring / dyeing and / or functionalizing materials for cleaning products, clothing and currency.

[0075] Wipes and sponge "mops" can, for example, deposit surfactant on the surface at the beginning of the wipe / mop movement and gradually add agents toward the end of the wipe / sponge to be absorbed into the remainder of the sponge and / or trailing desiccant.

[0076] Clothing items can have particles embedded within them through this process, potentially embedding precious metals into fine fabrics, while other methods may destroy the underlying veil or tape.

[0077] This technology can be used to gold-edge currency or high-value documents such as banknotes, bearer bonds, certificates, gold-edged securities, or promotional items (such as vouchers, invitations, etc.) to provide important visual cues or create a form of security marking.

[0078] A (uniform) porous / semi-permeable membrane / veil can be continuously pulled across an angled pressure difference, causing particle forced / entrained motion to be non-uniformly distributed across the width of the veil or tape. This can be done by varying the distance and / or location of the vacuum source on one side of the veil or tape to induce stronger flow at specific locations along the width, as in Figure 1(a).

[0079] Alternatively, the angle at which the bale or tape is presented on the liquid pump can be changed (as in Figure 1(b)) to use the pump direction and / or gravity to help distribute particles (particularly, but not limited to, colloids) towards the bottom end (relative to the flat portion) of the bale.

[0080] Both of these methods take advantage of the continuous plugging of the pores in the veil or tape, because the veil or tape is not uniform in porosity / permeability (significant variations in pass-through size / collection pore size / channel width) and therefore behaves differently as a "filtration medium." This can aid in further passing through the above processes and / or depositing particles (unblocked / undesired distributions). The initially treated veil or tape and the particles deposited therein can further influence deposition by modifying the pore characteristics (size, number—both of which affect flow, as shown in Figure 1(c)). Effects arising from the properties (or mere presence) of the deposited particles also play a role (magnetic attraction, chemical reactions, viscous effects such as skin formation and beading—which affect, for example, surface finish). These effects can be utilized to further influence the particle distribution, for example, by applying a strong magnetic field over a specific area / edge, or exposing a portion of the veil or tape to a reactant (e.g., immersing the edge), to further change properties and / or function; this is a useful technique for reacting deposited products in situ, which would otherwise be a pathway for particles that are too large (or difficult to handle) to be embedded in the veil or tape.

[0081] The affected width can be adjusted by using a blocking plate (i.e., mask) in front of the veil or tape to block particle flow, or behind the membrane to reduce vacuum / negative flow drawing through the veil or tape. Alternatively and / or additionally, a device (with appropriate / additional curtaining) (i.e., mask) can be passed over a portion of the veil or tape to create a narrow taper across the edge of the veil or tape, or when a machine that processes the entire size of the veil or tape is impractical; a large veil or tape disk can be gradient-applied when its edge is rotated through such a machine, or indeed, when the machine is sized from the center to the disk edge, increased travel speed at the edge can provide a more uniform coating, so a non-uniform deposition is desirable.

[0082] 2(a) through 2(d) schematically depict functional particle content of functionalized veils or tapes according to exemplary embodiments.

[0083] 2(a) schematically illustrates a linearly decreasing functional particle content of a functionalized veil or tape across its width. In this example, the method comprises controlling the angle (i.e., orientation) at which the veil or tape is presented on the pump to utilize pump direction and / or gravity to assist in distributing particles (particularly, but not limited to, colloids) toward the bottom end of the veil (relative to the flat portion). In this example, the angle is constant during the method, providing a linearly decreasing functional particle content of the functionalized veil or tape.

[0084] 2(b) schematically illustrates the functional particle content of a functionalized veil or tape decreasing nonlinearly across the width of the functionalized veil or tape. In this example, the method comprises changing the angle (i.e., orientation) at which the veil or tape is presented over a pump or vacuum source to utilize pump direction and / or gravity to help distribute particles (particularly, but not limited to, colloids) toward the bottom end of the veil (relative to the flat portion). In this example, the angle is not constant (i.e., varies) during the method, providing a nonlinearly decreasing functional particle content of the functionalized veil or tape.

[0085] 2(c) schematically illustrates the functional particle content of a functionalized veil or tape varying periodically across the width of the functionalized veil or tape. In this example, non-uniformly depositing functional particles in and / or on the veil or tape comprises masking the veil or tape to provide the periodic variation in the functional particle content of the functionalized veil or tape.

[0086] 2(d) schematically illustrates the non-periodically varying functional particle content of a functionalized veil or tape across its width. In this example, non-uniform deposition of functional particles in and / or on the veil or tape comprises masking the veil or tape and varying the angle (i.e., orientation) at which the veil or tape is presented above a pump or vacuum source to utilize the pump direction and / or gravity to help distribute particles (particularly, but not limited to, colloids) toward the bottom edge of the veil (relative to a plane) to provide the non-periodic variation in the functional particle content of the functionalized veil or tape.

Claims

1. 1. A method for providing a functionalized veil or tape for the manufacture of fiber reinforced composite parts, comprising: depositing functional particles in and / or on the veil or tape by flowing a fluid through the veil or tape to provide the functionalized veil or tape; the veil or tape comprises reinforcing fibers; The method wherein the fluid comprises functional particles.

2. The method of claim 1 , wherein the functional particles are conductive particles.

3. 3. The method of claim 1 or 2, wherein the reinforcing fibers are electrically insulating reinforcing fibers.

4. 4. The method according to any one of claims 1 to 3, wherein the veil comprises non-aligned and / or discontinuous reinforcing fibers or the tape comprises aligned and / or continuous reinforcing fibers.

5. 5. The method of claim 1, wherein depositing the functional particles in and / or on the veil or tape comprises depositing the functional particles non-uniformly in and / or on the veil or tape.

6. 6. The method of claim 5, wherein non-uniformly depositing the functional particles in and / or on the veil or tape comprises non-uniformly depositing the functional particles in and / or on the veil or tape across its width and / or length.

7. 7. The method of claim 5 or 6, wherein non-uniformly depositing the functional particles in and / or on the veil or tape comprises depositing the functional particles in and / or on a periphery of the veil or tape.

8. 8. The method of claim 5, wherein non-uniformly depositing the functional particles in and / or on the veil or tape comprises masking the veil or tape.

9. 9. The method of claim 1, wherein depositing the functional particles in and / or on the veil or tape comprises applying a magnetic and / or electric field while flowing the fluid through the veil or tape.

10. 10. The method of any one of claims 1 to 9, wherein depositing the functional particles in and / or on the veil or tape comprises depositing the functional particles on the reinforcing fibers and / or in the pores between them.

11. 11. The method of any one of claims 1 to 10, comprising reacting and / or functionalizing the functional particles.

12. 12. The method of any one of claims 1 to 11, comprising dispersing and / or suspending functional particles in the fluid.

13. 13. The method of any one of claims 1 to 12, wherein flowing the fluid through the veil or tape comprises applying a pressure differential to the fluid while flowing the fluid through the veil or tape.

14. 14. The method of any one of claims 1 to 13, wherein flowing the fluid through the veil or tape comprises directing the veil or tape relative to the flowing fluid.

15. 1. An apparatus for providing a functionalized veil or tape for the manufacture of fiber reinforced composite parts, comprising: means for depositing functional particles in and / or on said veil or tape by flowing a fluid through said veil or tape to provide said functionalized veil or tape; the veil or tape comprises reinforcing fibers; The apparatus, wherein the fluid comprises functional particles.

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