Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B15/00—Pretreatment of the material to be shaped, not covered by groups B29B7/00 - B29B13/00
  • B29B15/08—Pretreatment of the material to be shaped, not covered by groups B29B7/00 - B29B13/00 of reinforcements or fillers
  • B29B15/10—Coating or impregnating independently of the moulding or shaping step
  • B29B15/12—Coating or impregnating independently of the moulding or shaping step of reinforcements of indefinite length
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B15/00—Pretreatment of the material to be shaped, not covered by groups B29B7/00 - B29B13/00
  • B29B15/08—Pretreatment of the material to be shaped, not covered by groups B29B7/00 - B29B13/00 of reinforcements or fillers
  • B29B15/10—Coating or impregnating independently of the moulding or shaping step
  • B29B15/12—Coating or impregnating independently of the moulding or shaping step of reinforcements of indefinite length
  • B29B15/14—Coating or impregnating independently of the moulding or shaping step of reinforcements of indefinite length of filaments or wires
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B13/00—Conditioning or physical treatment of the material to be shaped
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
  • B29C43/22—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of indefinite length
  • B29C43/24—Calendering
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2071/00—Use of polyethers, e.g. PEEK, i.e. polyether-etherketone or PEK, i.e. polyetherketone or derivatives thereof, as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2077/00—Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2101/00—Use of unspecified macromolecular compounds as moulding material
  • B29K2101/12—Thermoplastic materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y70/00—Materials specially adapted for additive manufacturing
  • B33Y70/10—Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y80/00—Products made by additive manufacturing
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/02—Elements
  • C08K3/04—Carbon
  • C08K3/041—Carbon nanotubes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/40—Glass
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K7/00—Use of ingredients characterised by shape
  • C08K7/02—Fibres or whiskers
  • C08K7/04—Fibres or whiskers inorganic
  • C08K7/14—Glass

Definitions

• the present invention relates to a method of manufacturing a fibrous material prepreg of thermoplastic polymer in dry powder form.
• the invention relates to a method of manufacturing a preimpregnated fibrous material comprising an impregnation step for the preparation of a preimpregnated fibrous material, especially at its core, of reduced and controlled porosity, to obtain ribbons of preimpregnated fibrous material, of calibrated dimensions, directly usable for the manufacture of three-dimensional composite parts.
• fibrous material means an assembly of reinforcing fibers. Before it is shaped, it is in the form of wicks. After shaping, it comes in the form of strips (or tape), or tablecloths. When the reinforcing fibers are continuous, their assembly constitutes a fabric or a nonwoven (NCF). When the fibers are short, their assembly constitutes a felt or a nonwoven.
• Such preimpregnated fibrous materials are especially intended for the production of lightweight composite materials for the manufacture of mechanical parts having a three-dimensional structure and having good mechanical and thermal properties.
• these fibrous materials are able to evacuate electrostatic charges. They therefore have properties compatible with the manufacture of parts in particular in the fields of mechanics, civil or military aeronautics, and nautical, automotive, oil and gas, particularly offshore, storage gas, energy, health and medical, army and armaments, sports and recreation, and electronics.
• Such preimpregnated fibrous materials are also referred to as composite materials. They comprise the fibrous material, constituted by the reinforcing fibers, and a matrix constituted by the impregnating polymer.
• the primary role of this matrix is to maintain the reinforcing fibers in a compact form and to give the desired shape to the final product. This matrix also ensures the charge transfer between the fibers and therefore conditions the mechanical strength of the composite.
• Such a matrix is also used to protect the reinforcing fibers against abrasion and an aggressive environment, to control the surface appearance and to disperse any fillers between the fibers. The role of this matrix is important for the long-term behavior of the composite material, particularly with regard to fatigue and creep.
• a good quality of the three-dimensional composite parts manufactured from preimpregnated fibrous materials passes in particular through control of the process of impregnating the reinforcing fibers with the thermoplastic polymer.
• band is used to designate strips of fibrous material whose width is greater than or equal to 400 mm.
• ribbon is used to designate ribbons of calibrated width and less than or equal to 400 mm.
• wick is also used to refer to the fibrous material.
• thermoplastic polymer or thermosetting polymer was carried out according to several processes which depend in particular on the nature of the polymer, the type of final desired composite material and its field of application. applications. Powder impregnation or extrusion technologies at the angle head of molten polymer are often used to impregnate the reinforcing fibers with thermosetting polymers, such as epoxy resins, for example, as described in patent WO2012 / 066241. A2.
• thermoplastic polymers in particular those with a high glass transition temperature, which have a melt viscosity that is too high to obtain satisfactory impregnation of the fibers and of the semi-finished products. or finishes of good quality.
• Another known method of impregnation is the continuous passage of the fibers in an aqueous dispersion of polymer powder or aqueous dispersion of polymer particles or emulsion or aqueous polymer suspension.
• a dispersion of powders of micrometric size (approximately 20 ⁇ ) is used.
• the fibers After soaking in the aqueous solution, the fibers are impregnated with the polymer powder.
• the process then involves a drying step of passing the fibers through impregnated in a first oven to evaporate the water absorbed during soaking.
• a heat treatment step of passing the impregnated and dried fibers into a second heating zone at high temperature is then required to melt the polymer to adhere, disperse and coat the fibers.
• the main disadvantage of this method is the homogeneity of the deposit which is sometimes imperfect. Another problem with this process is the drying time and the energy consumption which strongly affects the cost of production. In addition the particle size of the powders usually used is fine (typically 20 ⁇ of D50 by volume) and this also increases the final cost of the pre-impregnated ribbon or web.
• the drying step of this method induces porosity in the pre-impregnated fibers by evaporation of the water.
• the preimpregnated fibrous material then needs to be shaped into ribbons for example.
• the melting temperature of the polymers depends in particular on their chemical nature. It can be relatively high for poly (methyl methacrylate) (PMMA) polymers, or even very high for poly (phenylene sulfide) (PPS), poly (ether ether ketone) (PEEK) or poly ( ether ketone ketone) (PEKK) for example. Temperature Therefore, the heating temperature can rise to temperatures above 250 ° C, and even higher than 350 ° C, temperatures that are much higher than the boiling point and the flash point of the solvent, which are respectively 305 ° C and 150 ° C. C for benzophenone.
• the document EP 0 406 067 filed in the joint names of Atochem and the French State, as well as the document EPO 201 367 describe a technique for impregnating a fluidized bed of polymer powder.
• the fibers penetrate into a closed fluidization vessel where, with regard to EP 0 406 067, they are optionally separated from each other by means of rollers or corrugated rolls, the fibers being electrostatically charged by friction in contact with these rollers. or cylinders. This electrostatic charge allows the polymer powder to stick to the surface of the fibers and thus to impregnate them.
• the international application WO 2016/062896 describes a wicking of wick by an electrostatic process in voluntary charge, by grounding the wick and application of a potential difference between the tip of a spray gun or powder nozzles and the wick .
• the document WO2008 / 135663 describes, in a third variant, the production of an impregnated fiber ribbon.
• the fiber ribbon is already preformed prior to the impregnation step, in the form of a ribbon formed of fibers held together by means of contention.
• the ribbon thus preformed is previously charged with static electricity and immersed in an enclosure containing a fluidized bed of fine polymer particles suspended in the compressed air, so as to coat the ribbon with a layer of polymer coating.
• Such a document does not make it possible to impregnate one or more fiber strands simultaneously or a shaping, continuously, the pre-impregnated rovings in the form of ribbons.
• EP2586585 also describes the principle of impregnating fibers by passing them into a fluidized bed of polymer particles. On the other hand, he does not describe continuous shaping of one or more wicks thus impregnated, in the form of one or more unidirectional parallel ribbons.
• the international application WO 2015/121583 describes a method of manufacturing a fibrous material pre-impregnated by impregnation of said material in a fluidized bed and hot calendering of said wick.
• the hot calendering is carried out downstream of the impregnation device and makes it possible to homogenize the distribution of the polymer and the impregnation of the fibers.
• the porosity obtained is controlled and reproducible but not quantified.
• EP0335186 describes the possibility of using a calender or a press for compacting a composite comprising preimpregnated metal fibers, used for the manufacture of molded bodies for the shielding against electromagnetic radiation. It does not disclose impregnating one or more fiber strands and continuously shaping them into one or more unidirectional parallel strips by hot calendering.
• the document WO92 / 20521 describes the possibility of impregnating a wick of fibers by passing it in a fluidized bed of particles of thermoplastic powder.
• the fibers thus coated with polymer particles are heated in an oven or heater so that the polymer penetrates well and covers the fibers.
• a post-treatment of the obtained prepreg fibrous reinforcement can be to pass it through a polishing roll assembly to improve the impregnation with the still liquid matrix.
• One or more superposed fibrous reinforcements may further be placed between two rollers so as to form a band.
• Such a document does not make it possible to impregnate one or more strands of fibers and shaping, continuously, preimpregnated strands in the form of one or more unidirectional parallel strips.
• the quality of the pre-impregnated fibrous material tapes depends not only on the homogeneity of the impregnation of the fibers and therefore the control and reproducibility of the porosity of the preimpregnated fibrous material, but also the size and more particularly the width and thickness of the final ribbons. Regularity and control of these two dimensional parameters make it possible to improve the mechanical strength of the materials.
• this mode of impregnation melt does not allow to obtain high fiber levels or high production speeds because of the high viscosity of thermoplastic resins, especially when they have high glass transition temperatures, which is necessary to obtain high performance composite materials.
• the use of organic solvents usually involves the appearance of defects in the material as well as environmental, health and safety risks in general.
• the slitting of plies for obtaining calibrated ribbons and the splicing of these ribbons induces an additional cost of manufacture.
• the slitting also generates significant dust problems that pollute the ribbons of pre-impregnated fibrous materials used for robot removal and can cause malfunctions of the robots and / or imperfections on the composites. This potentially leads to robot repair costs, a shutdown of production and the scrapping of non-compliant products. Finally, during the slitting step, a not insignificant amount of fibers is deteriorated, inducing a loss of properties, and in particular a reduction of the mechanical strength and conductivity, ribbons of preimpregnated fibrous material.
• the invention therefore aims to remedy at least one of the disadvantages of the prior art.
• the invention aims in particular to provide a method of manufacturing a preimpregnated fibrous material, by an impregnation technique associating a control of the residence time in the impregnating device to a control of the development of said fibrous material to level of said device, and to obtain a preimpregnated fibrous material having impregnation of the fibers, particularly at the core, and controlled dimensions, with a reduced, controlled and reproducible porosity on which the performance of the final composite part depend.
• the subject of the invention is a process for manufacturing a preimpregnated fibrous material comprising a fibrous material made of continuous fibers and at least one thermoplastic polymer matrix, comprising a step of impregnation, particularly at the core, of said material. fibrous in the form of a wick or several parallel locks with at least one thermoplastic polymer matrix in the form of a powder.
• the invention also relates to a unidirectional ribbon of preimpregnated fibrous material, in particular ribbon wound on a reel, characterized in that it is obtained by a method as defined above.
• the invention further relates to a use of the tape as defined above in the manufacture of three-dimensional parts.
• Said manufacture of said composite parts concerns the fields of transport, in particular automobile, oil and gas, in particular offshore, gas storage, civil or military aeronautics, nautical, railway; renewable energy, in particular wind turbine, tidal turbine, energy storage devices, solar panels; thermal protection panels; sports and recreation, health and medical, ballistics with weapon or missile parts, security and electronics.
• the invention also relates to a three-dimensional composite part, characterized in that it results from the use of at least one unidirectional tape of preimpregnated fibrous material as defined above.
• the subject of the invention is a process for manufacturing a preimpregnated fibrous material comprising a fibrous material made of continuous fibers and at least one thermoplastic polymer matrix, characterized in that said preimpregnated fibrous material is produced in a single unidirectional ribbon or in a plurality unidirectional parallel ribbons and in that said method comprises a step of impregnation, in particular at the core, of said fibrous material in the form of a wick or of several parallel locks by said thermoplastic polymer in the form of a powder, said impregnation step being carried out with said at least one thermoplastic polymer and said fibrous material whose D90 / D10 ratio by volume of the thermoplastic polymer particles is from 1.5 to 50, in particular from 2 to 10, and the diameter ratio average volume (D50) of the thermoplastic polymer particles on the average diameter unit fibers of said fibrous material is from 3 to 40, excluding a process for impregnating an aqueous suspension of a material fiber consisting of carbon fibers by a thermoplastic poly
• the inventors have unexpectedly found that, on the one hand, the control of the residence time in the powder makes it possible to impregnate the fibrous material with the thermoplastic polymer matrix, in particular at the core with a well-controlled powder (resin) ratio and on the other hand that below a D50 of 25 ⁇ , the size of the particles is too small to be fluidized or correctly projected, in particular by gun (s) or dusting nozzle (s) at the inlet of a roller, which leads to a poor implementation and therefore poor impregnation.
• Thermoplastic, or thermoplastic polymer is understood to mean a material that is generally solid at ambient temperature, that can be semi-crystalline or amorphous, and that softens during an increase in temperature, in particular after passing its glass transition temperature (Tg). and flows at a higher temperature when it is amorphous, or can present a blunt fusion at the passage of its so-called melting temperature (Tf) when it is semi-crystalline, and which becomes solid again during a decrease in temperature below its crystallization temperature (for a semi-crystalline) and below its glass transition temperature (for an amorphous).
• Tg glass transition temperature
• Tf melting temperature
• Tg and Tf are determined by Differential Scanning Calorimetry (DSC) according to standard 1 1357-2: 2013 and 1 1357-3: 2013 respectively.
• thermoplastic polymer As regards the polymer constituting the impregnating matrix of the fibrous material, it is advantageously a thermoplastic polymer or a mixture of thermoplastic polymers. This polymer or mixture of thermoplastic polymers is crushed in powder form so that it can be used in a device such as a tank, in particular in a fluidized bed.
• the device in the form of a tank, in particular in a fluidized bed, can be open or closed.
• thermoplastic polymer or thermoplastic polymer blend further comprises carbonaceous fillers, in particular carbon black or carbon nanofillers, preferably chosen from carbon nanofillers, in particular graphenes and / or carbon nanotubes, and or carbon nanofibrils or mixtures thereof.
• carbonaceous fillers in particular carbon black or carbon nanofillers, preferably chosen from carbon nanofillers, in particular graphenes and / or carbon nanotubes, and or carbon nanofibrils or mixtures thereof.
• said thermoplastic polymer comprises at least one additive, especially chosen from a catalyst, an antioxidant, a thermal stabilizer, a UV stabilizer, a light stabilizer, a lubricant, a filler, a plasticizer, a flame retardant, a nucleating agent , a chain extender and a dye or a mixture thereof.
• thermoplastic polymer or thermoplastic polymer blend may further comprise liquid crystal polymers or cyclized poly (butylene terephthalate), or mixtures containing them, such as the CBT100 resin marketed by CYCLICS CORPORATION.
• liquid crystal polymers or cyclized poly (butylene terephthalate), or mixtures containing them such as the CBT100 resin marketed by CYCLICS CORPORATION.
• thermoplastic polymers forming part of the impregnation matrix of the fibrous material can be chosen from:
• PA aliphatic, cycloaliphatic polyamides
• PPAs polyphthalamides
• polyureas in particular aromatic
• polymers and copolymers of the family of acrylics such as polyacrylates, and more particularly polymethyl methacrylate (PMMA) or its derivatives
• PAEK polyaryletherketone
• PEEK polyetheretherketone
• PAEKK polyaryletherketone ketones
• PEKK polyetherketone ketone
• polyarylsulfides in particular polyphenylene sulfides (PPS),
• polyarylsulphones in particular polyphenylene sulphones (PPSU),
• polystylenes in particular polypropylene (PP);
• PLA polylactic acid
• PVA polyvinyl alcohol
• PVDF polyvinylidene fluoride
• PTFE polytetrafluoroethylene
• PCTFE polychlorotrifluoroethylene
• thermoplastic polymer when said thermoplastic polymer is in a mixture, it is added to the tank in powder form previously obtained by “dry blend” or compound or directly into the tank in the form of “dry blend".
• it is added in powder form previously obtained by “dry blend” or directly into the tank in the form of “dry blend” and the mixture is a mixture of PEKK and PEI.
• the proportion by weight of polymer P1 and P2 is from 1 -99% to 99-1%.
• the PEKK / PEI mixture is from 90-10% to 60-40% by weight, in particular from 90-10% to 70-30% by weight.
• the thermoplastic polymer may be the non-reactive final polymer that will impregnate the fibrous material or a reactive prepolymer, which will also impregnate the fibrous material, but is capable of reacting on itself or with another prepolymer, depending on the chain ends being carried. by said prepolymer, after impregnation, or with a chain extender and in particular during heating at a heating calender.
• said prepolymer may comprise or consist of at least one reactive (polyamide) prepolymer carrying on the same chain (ie on the same prepolymer), two terminal functions X 'and Y' functions respectively coreactive with each other by condensation, more particularly with X 'and Y' being amine and carboxy or carboxy and amine respectively.
• said prepolymer may comprise or consist of at least two polyamide prepolymers which are reactive with one another and each carrying two identical terminal functions X 'or Y' (identical for the same prepolymer and different between the two prepolymers), said function X 'of a prepolymer that can react only with said function Y' of the other prepolymer, in particular by condensation, more particularly with X 'and Y' being amino and carboxy or carboxy and amine respectively.
• said prepolymer may comprise or be composed of at least one prepolymer of said thermoplastic polyamide polymer carrying n terminal reactive functions X, chosen from: -NH2, -CO2H and -OH, preferably NH2 and -CO2H with n being 1 to 3, preferably 1 to 2, more preferably 1 or 2, more particularly 2 and at least one Y-A'-Y chain extender, with A 'being a hydrocarbon biradical, of non-polymeric structure, carrying of 2 identical terminal reactive functional groups Y, reactive by polyaddition with at least one function X of said prepolymer a1), preferably with a molecular mass of less than 500, more preferably less than 400.
• n terminal reactive functions X chosen from: -NH2, -CO2H and -OH, preferably NH2 and -CO2H with n being 1 to 3, preferably 1 to 2, more preferably 1 or 2, more particularly 2 and at least one Y-A'-Y chain extender, with A 'being
• the number-average molecular weight Mn of said final polymer of the thermoplastic matrix is preferably in a range from 10,000 to 40,000, preferably from 12,000 to 30,000. These Mn values may correspond to inherent viscosities greater than or equal to 0.8 such determined in m-cresol according to ISO 307: 2007 but changing the solvent (use of m-cresol in place of sulfuric acid and the temperature being 20 ° C).
• Said reactive prepolymers according to the two options mentioned above have a number-average molecular weight Mn ranging from 500 to 10,000, preferably from 1,000 to 6,000, in particular from 2,500 to 6,000.
• Mn are determined in particular by the calculation from the rate of terminal functions determined by potentiometric titration in solution and the functionality of said prepolymers. Mn masses can also be determined by size exclusion chromatography or by NMR.
• the polyamide may be a homopolyamide or a copolyamide or a mixture thereof.
• the polymers constituting the matrix are chosen from polyamides (PA), in particular chosen from aliphatic polyamides, in particular PA1 1 and PA12, cycloaliphatic polyamides, and semi-aromatic polyamides (polyphthalamides) which may be modified by urea units, and copolymers thereof, polymethyl methacrylate (PPMA) and copolymers thereof, polyetherimides (PEI), polyphenylene sulfide (PPS), Poly (phenylene sulfone) (PPSU), polyetherketoneketone (PEKK), polyetheretherketone (PEEK), fluorinated polymers such as polyvinylidene fluoride (PVDF).
• PA polyamides
• PA polyamides
• the VDF content must be greater than 80% by weight, or even better 90% by weight, to ensure good mechanical strength to the structural part, especially when it is subjected to thermal and chemical stresses.
• the comonomer may be a fluorinated monomer such as, for example, vinyl fluoride.
• PAEK PolyArylEtherKetone
• PEK polyether ketones PEEK poly (ether ether ketone) and polyetherketone
• ketone) PEKK Poly (ether ketone ether ketone ketone) PEKEKK or PA high temperature glass transition Tg).
• said thermoplastic polymer is selected from amorphous polymers whose glass transition temperature is such that Tg> 80 ° C and / or from semi-crystalline polymers whose melting point T f is> 150 ° C.
• thermoplastic polymer is:
• polyamide 6 PA-6
• PA-1 1 PA-1 1
• PA-12 polyamide 1 2
• PA-66 PA-66
• PA-46 polyamide 610
• PA-610 polyamide 612
• PA-1010 PA-1010
• PA-1012 polyamide 1012
• PA-1012 polyamide 1012
• a semi-aromatic polyamide optionally modified with urea units, in particular a semi-aromatic polyamide of formula X / YAr, as described in EP1505099, in particular a semi-aromatic polyamide of formula A XT in which A is chosen from a unit obtained from an amino acid, a unit obtained from a lactam and a unit having the formula (diamine Ca).
• the pattern (diamine in Ca) being chosen among the linear or branched aliphatic diamines, the cycloaliphatic diamines and the alkylaromatic diamines and the (Cb diacid) unit being chosen from linear or branched aliphatic diacids, cycloaliphatic diacids and aromatic diacids;
• XT denotes a unit obtained from the polycondensation of a diamine in Cx and terephthalic acid, with x representing the number of carbon atoms of the diamine in Cx, x being between 6 and 36, advantageously between 9 and 18, in particular a polyamide of formula A 6T, A 9T, A 10T or A 1 1 T, A being as defined above, in particular a polyamide PA 6 / 6T, 66 / 6T, 6I / 6T, MPMDT / 6T, PA1 1 / 10T, 1 1 / 6T / 10T, MXDT / 10T or MPMDT / 10T, BACT / 10T, MXD6 and MXD10 and block copolymers, especially polyamide / polyether (PEBA).
• PEBA polyamide / polyether
• T is terephthalic acid
• MXD is m-xylylene diamine
• MPMD is methylpentamethylene diamine
• BAC is bis (aminomethyl) cyclohexane.
• the fibers of constitution of said fibrous material they are in particular fibers of mineral, organic or vegetable origin.
• the fibers of mineral origin mention may be made of carbon fibers, glass fibers, basalt fibers, silica fibers, or silicon carbide fibers, for example.
• the fibers of organic origin mention may be made of thermoplastic or thermosetting polymer-based fibers, such as semi-aromatic polyamide fibers, aramid fibers or polyolefin fibers, for example.
• they are based on amorphous thermoplastic polymer and have a glass transition temperature Tg greater than the Tg of the polymer or thermoplastic polymer mixture of constitution of the impregnation matrix when the latter is amorphous, or greater than the Tf of the polymer or mixture of thermoplastic polymer constitution of the impregnation matrix when the latter is semi-crystalline.
• they are based on semicrystalline thermoplastic polymer and have a melting temperature Tf greater than the Tg of the polymer or thermoplastic polymer mixture of constitution of the impregnation matrix when the latter is amorphous, or greater than the Tf of the polymer or mixture of thermoplastic polymer constitution of the impregnation matrix when the latter is semi-crystalline.
• the organic fibers constituting the fibrous material during impregnation with the thermoplastic matrix of the final composite.
• the fibers of vegetable origin mention may be made of natural fibers based on flax, hemp, lignin, bamboo, silk, especially spider, sisal, and other cellulosic fibers, in particular viscose fibers. These plant-based fibers can be used pure, treated or coated with a coating layer, in order to facilitate the adhesion and impregnation of the thermoplastic polymer matrix.
• the fibrous material may also be a fabric, braided or woven with fibers. It can also correspond to fibers with holding wires.
• organic fibers may be mixed with the mineral fibers to be impregnated with thermoplastic polymer and form the preimpregnated fibrous material.
• the locks of organic fibers may have several grammages. They can also have several geometries.
• the fibers may be in the form of short fibers, which then compose the felts or nonwovens which may be in the form of strips, sheets, or pieces, or in the form of continuous fibers, which make up the 2D fabrics, the braids or unidirectional (UD) or non-woven fibers.
• the fibers constituting the fibrous material may also be in the form of a mixture of these reinforcing fibers of different geometries.
• the fibers are continuous.
• the fibrous material is constituted by continuous fibers of carbon, glass or silicon carbide or their mixture, in particular carbon fibers. It is used in the form of a lock or several locks.
• said fibrous material is made of glass fibers and said ratio D507 average diameter of the unit fibers is from 3 to 15, in particular from 3 to 10.
• said fibrous material is made of glass fibers and said ratio D50 / average diameter of the unit fibers is from 4 to 15, in particular from 4 to 10.
• said fibrous material is made of carbon fibers and said ratio D50 / average diameter of the unit fibers is from 10 to 40.
• thermoplastic impregnating polymers In pre-impregnated materials also known as "ready-to-use", the polymer or mixture of thermoplastic impregnating polymers is distributed uniformly and homogeneously around the fibers.
• the thermoplastic impregnation polymer In this type of material, the thermoplastic impregnation polymer must be distributed in a manner that more homogeneous possible within the fibers to obtain a minimum of porosities, ie a minimum of voids between the fibers.
• porosities in this type of material can act as points of concentration of stress, during a mechanical tensile stress for example, and which then form fracture initiation points of the pre fibrous material. -impregnated and weakened mechanically.
• a homogeneous distribution of the polymer or polymer mixture thus improves the mechanical strength and the homogeneity of the composite material formed from these preimpregnated fibrous materials.
• the level of fibers in said impregnated fibrous material is 45 to 65% by volume, preferably 50 to 60% by volume, especially 54 to 60% by volume.
• the measurement of the impregnation rate can be carried out by image analysis (use of microscope or camera or digital camera, in particular), a cross section of the ribbon, by dividing the surface of the tape impregnated with the polymer. by the total surface of the product (surface impregnated plus surface of the porosities).
• image analysis use of microscope or camera or digital camera, in particular
• a cross section of the ribbon by dividing the surface of the tape impregnated with the polymer. by the total surface of the product (surface impregnated plus surface of the porosities).
• the porosity rate of said preimpregnated fibrous material is between 0% and 30%, especially from 1% to 10%, in particular from 1% to 5%.
• the porosity rate corresponds to the closed porosity rate and can be determined either by electron microscopy or as being the relative difference between the theoretical density and the experimental density of said preimpregnated fibrous material as described in the examples of this section. invention.
• Said impregnation step is carried out by powder deposition, fluidized bed or by projection by means of spray gun (s) or powder coating nozzle (s).
• it is carried out by fluidized bed in an impregnation tank.
• An exemplary unit for implementing the fluidized bed manufacturing method in an impregnating tank is described in the international application WO 2015/121583 and is represented in FIG. 1, with the exception of the tank (otherwise known as the tank).
• impregnation which in the case of the invention comprises a fluidized bed provided with a loading part ( Figure 3) which can be a compression roller ( Figure 4)).
• the compression roller can be fixed or rotatable.
• the impregnation step of the fibrous material is carried out by passing one or more locks in a continuous impregnation device, comprising a tank (20), in particular comprising a fluidized bed (22) of polymer powder.
• the polymer (s) or polymer powder is suspended in a gas G (air for example) introduced into the tank and circulating in the tank through a hopper 21.
• the wick or wicks are circulated in this fluidized bed 22.
• the tank may have any shape, in particular cylindrical or parallelepipedal, in particular a rectangular parallelepiped or a cube, advantageously a rectangular parallelepiped.
• the tank may be an open or closed tank.
• it is open.
• the tank is then equipped with a sealing system so that the polymer powder can not leave said tank.
• thermoplastic polymer matrix is in powder form, in particular in suspension in a gas, in particular air, but can not be dispersed in a solvent or in water.
• Each wick to be impregnated is unwound from a device (10) reels (1 1) under the traction generated by cylinders (not shown).
• the device (10) comprises a plurality of reels (1 1), each reel for unwinding a wick to impregnate.
• the device (10) comprises a plurality of reels (1 1), each reel for unwinding a wick to impregnate.
• Each reel (1 1) is provided with a brake (not shown) so as to apply a tension on each strand of fibers.
• an alignment module (12) makes it possible to arrange the fiber locks parallel to one another. In this way the fiber locks can not be in contact with each other, which makes it possible to avoid mechanical degradation of the fibers by friction between them.
• the fiber wick or the parallel fiber locks then pass into a tank (20), in particular comprising a fluidized bed (22), provided with a loading piece which is a compression roll (23) in the case of Figure 1.
• the fiber lock or the parallel fiber locks then spring out of the tank after impregnation after checking the residence time in the powder.
• docking part any system on which the wick has the ability to scroll in the tank.
• the docking piece can have any shape from the moment the wick can scroll on.
• FIG. 1 An example of a docking piece, without restricting the invention to it, is detailed in FIG.
• This impregnation is performed to allow the polymer powder to penetrate the core of the fiber wick and adhere to the fibers sufficiently to support the transport of the powdered wick from the tub.
• the or wicks pre-impregnated with the powder is (are) directed (s) then to a heating calendering device, with possibility of preheating before calendering and optional heating post-calendering.
• this impregnation step may be completed by a step of covering the wick or pre-impregnated wicks, just at the outlet of the fluidized bed powder (22) impregnation vat (22), and just before the calendering shaping step.
• the airlock of the tank (20) (fluidized bed 22) can be connected to a covering device (30) which can comprise a cover angle head, as is also described in the patent EP0406067.
• the overlay polymer may be the same or different from the fluidized bed polymer powder. Preferably, it is of the same nature.
• Such a covering not only makes it possible to complete the fiber impregnation step in order to obtain a final polymer volume content in the desired range and to avoid the presence on the surface of the pre-impregnated wick, of a level of fibers that is locally too high. important, which would interfere with the welding of the steps during the manufacture of the composite part, in particular for obtaining fibrous materials known as "ready to use” good quality, but also to improve the performance of the composite material obtained.
• the process of the invention as indicated above is carried out by the dry method, excluding an electrostatic process in voluntary charge.
• voluntary charge means that a potential difference is applied between the fibrous material and the powder.
• the charge is notably controlled and amplified.
• the powder grains then impregnate the fibrous material by attracting the charged powder opposite the fiber.
• the powder can be electrically charged, negatively or positively, by different means (potential difference between two metal electrodes, mechanical friction on metal parts, etc.) and charge the fiber inversely (positively or negatively).
• the method of the invention does not exclude the presence of electrostatic charges which could appear by friction of the fibrous material on the elements of the unit of implementation before or at the level of the tank but which are in any case involuntary loads.
• the level of fibers in said impregnated fibrous material is 45 to 65% by volume, preferably 50 to 60% by volume, in particular 54 to 60% by volume.
• an optional de-sizing step can be performed before the fibrous material passes into the tank.
• sizing refers to the surface treatments applied to the reinforcing fibers at the end of the die (textile sizing) and on the fabrics (plastic sizing).
• the "textile" size applied to the filaments at the outlet of the die consists of depositing a bonding agent ensuring the cohesion of the filaments between them, reducing abrasion and facilitating subsequent handling (weaving, draping, knitting) and avoiding formation. electrostatic charges.
• the "plastic" or “finish” size applied to the fabrics consists in depositing a bridging agent whose roles are to ensure a physico-chemical bond between the fibers and the resin and to protect the fiber from its environment.
• the level of fibers in said impregnated fibrous material is from 50 to 60%, in particular from 54 to 60% by volume.
• the residence time in the powder is from 0.01 s to 10 s, preferably from 0.1 s to 5 s, and in particular from 0.1 s to 3 s.
• the residence time of the fibrous material in the powder is essential for the impregnation, especially at the core, of said fibrous material.
• the level of polymer matrix impregnating the fibrous material is too great and the mechanical properties of the preimpregnated fibrous material will be poor.
• the vessel used in the process of the invention comprises a fluidized bed and said impregnation stage is carried out with simultaneous expansion of said wick or said wicks between the inlet and the outlet of said fluidized bed.
• fluidized bed inlet corresponds to the vertical tangent of the edge of the vessel which comprises the fluidized bed.
• outlet of the fluidized bed corresponds to the vertical tangent of the other edge of the vessel which comprises the fluidized bed.
• the distance between the inlet and the outlet of the tank corresponds to the diameter in the case of the cylinder, to the side in the case of a cube or to the width or length in the case of a rectangular parallelepiped.
• the development consists in singling out as much as possible each constituent filament of said wick from the other filaments which surround it in its nearest space. It corresponds to the transverse spreading of the wick.
• the transverse spreading or the width of the wick increases between the inlet of the fluidized bed (or of the vessel comprising the fluidized bed) and the outlet of the fluidized bed (or of the vessel comprising the fluidized bed) and thus allows improved impregnation, especially at the core of the fibrous material.
• the fluidized bed can be open or closed, in particular it is open.
• the fluidized bed comprises at least one mating piece, said bit or said bits being in contact with a part or the whole of the surface of said at least one mating piece.
• FIG. 3 details a tank (20) comprising a fluidized bed (22) with a height-adjustable, height-adjustable bartack (82).
• the wick (81 a) corresponds to the wick before impregnation which is in contact with a part or the totality of the surface of the said at least one piece of docking and thus runs partially or totally on the surface of the piece of baiting ( 82) said system (82) being immersed in the fluidized bed where the impregnation takes place. Said wick then leaves the tank (81b) after checking the residence time in the powder.
• Said bit (81 a) may or may not be in contact with the edge of the bowl (83a) which may be a rotating or fixed roll or a parallelepipedal edge.
• said wick (81 a) is in contact or not with the edge of the tank (83a).
• the edge of the tank (83b) is a roller, in particular cylindrical and rotary.
• Said bit (81b) may or may not be in contact with the edge of the bowl (83b) which may be a roller, in particular a cylindrical and rotary or fixed roll, or a parallelepipedal edge.
• the edge of the bowl (83b) which may be a roller, in particular a cylindrical and rotary or fixed roll, or a parallelepipedal edge.
• said wick (81b) is in contact with the edge of the tank (83b).
• the edge of the tank (83b) is a roller, in particular cylindrical and rotary.
• said wick (81 a) is in contact with the edge of the tank (83a) and the edge of the tank (83b) is a roller, in particular cylindrical and rotating and said wick (81 b) is in contact with the edge of the tank (83b), and the edge of the tank (83b) is a roller, in particular cylindrical and rotating.
• said mating piece is perpendicular to the direction of said wick or said locks.
• said development of said wick or said wicks is performed at least at said at least one part of the baiting.
• the blooming of the wick is therefore mainly at the level of the mating part but can also be performed at the edge or edges of the tank if there is contact between the wick and said edge.
• said at least one mating piece is a convex, concave or cylindrical compression roll.
• the convex form is favorable to the development whereas the concave form is unfavorable to the blooming although it is nevertheless carried out.
• compression roll means that the wicking bit rests partially or completely on the surface of said compression roller, which induces the development of said wick.
• said at least one compression roll is of cylindrical shape and the percentage of opening of said wick or said locks between the inlet and the outlet of said fluidized bed is between 1% and 400%, preferably between 30% and 400%. preferably between 30% and 150%, preferably between 50% and 150%.
• the development is a function of the fibrous material used. For example, the blooming of a carbon fiber material is much greater than that of a flax fiber.
• the development is also a function of the number of fibers or filaments in the wick, their average diameter and their cohesion by the size.
• the diameter of said at least one compression roller is from 3 mm to 500 mm, preferably from 10 mm to 100 mm, in particular from 20 mm to 60 mm.
• the compression roller is cylindrical and not grooved and in particular is metallic.
• the mating part is at least one compression roll
• a single compression roll is present in the fluidized bed and said impregnation is performed at the angle ⁇ formed by said wick or said locks between the inlet of said compression roller and the vertical tangent to said compression roller.
• the angle ⁇ formed by said wick or said wicks between the inlet of said compression roller and the vertical tangent to said compression roller allows the formation of an area in which the powder will concentrate thus leading to a "wedge effect" which with the simultaneous development of the wick by said compression roller allows impregnation over a larger width of wick and thus improved impregnation compared to techniques of the improved prior art.
• the coupling with the controlled residence time then allows a thorough impregnation.
• the angle ⁇ is from 0 to 89 °, preferably 5 ° to 85 °, preferably from 5 ° to 45 °, preferably from 5 ° to 30 °.
• a value of the angle ai equal to 0 ° therefore corresponds to a vertical fiber. It is obvious that the height of the cylindrical compression roller is adjustable thus allowing to position the fiber vertically.
• the edge of the tank (83a) is equipped with a roller, in particular a cylindrical and rotary roller on which said wick or said wicks runs, thus leading to a prior development.
• one or more difficulties are present downstream of the vessel comprising the fluidized bed at which blooming is initiated.
• the blooming is initiated at the said one or more of the aforementioned obstacles and continues at the edge of the tank (83a).
• Fig. 4 discloses an embodiment, but not limited thereto, to a single compression roll, with a vessel (20) comprising a fluidized bed (22) in which a single cylindrical compression roll is present and showing the angle CH.
• the arrows at the fiber indicate the direction of travel of the fiber.
• the level of said powder in said fluidized bed is at least at the mid-height of said compression roller.
• the angle ⁇ 1 is as defined above.
• the two compression rollers are of identical or different shape and chosen from a convex, concave or cylindrical shape.
• the two compression rollers are identical and cylindrical non-corrugated and in particular metal.
• the diameter of the two compression rollers may also be the same or different and is as defined above.
• the diameter of the two compression rollers is identical.
• the two compression rollers R 1 and R 2 may be at the same level with respect to each other and relative to the bottom of the vessel (FIGS. 6 and 7) or offset relative to one another and relative to each other. at the bottom of the tank, the height of the compression roller Ri being greater or smaller than that of the compression roller R2 relative to the bottom of the tank ( Figures 5 and 8).
• said impregnation is therefore performed at the angle ⁇ formed by said wick or said wicks between the inlet of said compression roller Ri and the vertical tangent to said compression roller on one face of said wick and at the level of the angle 02 formed by said wick or said wicks between the inlet of said compression roller R2 and the vertical tangent to said compression roller R2 on the opposite side of said wick which is obtained by passing over the roller R2.
• said lock in this embodiment is subject to expansion at each angle ⁇ 1 and ⁇ 2.
• FIG. 6 describes an embodiment, without being limited thereto, to two compression rolls R 1 and R 2, R 1 preceding R 2, with a vessel (20) comprising a fluidized bed (22) in which the two compression rollers cylindrical, at the same level and side by side, are present and showing the case where said one or more wicks emerge between said compression rolls R 1 and R 2.
• the angle ⁇ 2 is equal to 0 and said one or more bits pass over the roller R2.
• the arrows at the fiber indicate the direction of travel of the fiber.
• said wick or said strands pass (nt) between said said compression rollers R 1 and R 2 and spring (ent) after being in contact with a part or the whole of the surface of said compression roller R2.
• said wick or said wicks is (are) in input contact with a part or the totality of the surface of said compression roller Ri and spring (ent) outside the compression roller R2 after being in contact with a part or all of the surface of said compression roller R2, under the roller R2, the angle O 2 being formed by said wick or said wicks between the inlet of said compression roller R2 and the vertical tangent to said compression roller R2.
• the angle a2 90 °.
• Said impregnation is therefore performed at the angle ⁇ formed by said wick or said wicks between the inlet of said compression roller Ri and the vertical tangent to said compression roller on one side of said wick and at the angle 02 formed by said wick or said wicks between the inlet of said compression roller R2 and the vertical tangent to said compression roller R2 on the same face of said wick, but the blooming also impregnates the other face.
• said lock in this embodiment is subject to expansion at each angle ⁇ 1 and ⁇ 2.
• Figure 7 shows an exemplary embodiment with two compression rollers R1 and R2 at the same level relative to each other.
• the distance between the two compression rollers R 1 and R 2 is 0.15 mm to the length equivalent to the maximum dimension of the vessel, preferably ranging from 10mm to 50mm and the difference in height between the two compression rollers R 1 and R 2 is from 0 to the height corresponding to the maximum height of the vessel subtracted from the diameters of the two compression rollers, preferably from 0.15mm to the height corresponding to the maximum height of the tank subtracted diameters of the two compression rollers, more preferably at a height difference of between 10mm and 300mm, R2 being the upper compression roll.
• FIG. 8 describes an embodiment, without being limited thereto, to two compression rolls R 1 and R 2, R 1 preceding R 2, with a vessel (20) comprising a fluidized bed (22) in which two cylindrical compression rollers at different levels are present and showing the angle ai and 02.
• the diameter of the compression rollers R 1 and R 2 is shown as identical in FIGS. 5, 6, 7 and 8, but the diameter of each cylindrical compression roll may be different, the diameter of the compression roll R 1 may be greater or smaller than that of the compression roller R2 in the range as defined above.
• the diameter of the two compression rollers is identical. It would not depart from the scope of the invention if the compression roller Ri was greater than the compression roller R2.
• a third compression roll R3 is additionally present and situated between the compression rollers R 1 and R 2 in the height direction (FIG. 9 ).
• said wick or said wicks is (are) in input contact with a part or the totality of the surface of said compression roller Ri and then with a part or the totality of the surface of said compression roller R3 and spring (ent) after having has been in contact with a part or the whole of the surface of said compression roller R2.
• said impregnation is performed on a face of said wick or said wicks at the angle ⁇ formed by said wick or said wicks between the inlet of said at least one compression roller Ri and the vertical tangent to the compression roller Ri as well as at the angle formed by said wick or said wicks and the vertical tangent to the compression roller R3 and on the other side at the angle 02 formed by said wick or said wicks and the tangent vertical to the R2 compression roll.
• the angle O 2 formed by said wick or said wicks between the inlet of said at least one roller R2 and the vertical tangent to said compression roll R2 is from 180 ° to 45 °, in particular from 120 ° to 60 °.
• the angle ⁇ is from 0 ° to 180 °, advantageously from 45 ° to 135 °.
• FIG. 9 describes an embodiment, without being limited to it, with a tank (20) comprising a fluidized bed (22) with two compression rollers R 1 and R 2, R 1 preceding R 2, and a third compression roll R 3 and showing CM angles,
• the diameter of the compression rollers R 1, R 2 and R 3 is shown as the same in FIG. 9 but the diameter of each cylindrical compression roll may be different, or two compression rolls may have the same diameter and the third a different diameter greater than lower, in the range as defined above.
• the diameter of the three compression rollers is identical.
• a second control of the development of said wick or said wicks is performed at the compression roller R3 and a third control of the development is performed at the compression roller R3.
• the residence time in this third variant is as defined above.
• the level of said powder in said fluidized bed is at least at the mid-height of said compression roller R2. It would not be departing from the scope of the invention if in this third variant, said wick or said wicks is (are) in contact with some or all of the surface of said compression roller Ri and then with some or all of of the surface of said compression roller R2 and spring (ent) after being in contact with a part or the whole of the surface of said compression roller R 3 .
• the tank used in the method of the invention does not have a fluidized bed but comprises a spray gun (s) or powder coating nozzle (s) at the inlet of said roll. powder and said impregnation step is carried out with simultaneous expansion of said wick or said wicks between the inlet and the outlet of the tank.
• the residence time in the fluidized bed of powder is controlled and the tank can be provided with the same parts for docking, in particular one or more compression rollers as defined above.
• the residence time in the tank is from 0.01 s to 10 s, preferably from 0.1 s to 5 s, and in particular from 0.1 s to 3 s.
• the present invention relates to a method as defined above characterized in that a single thermoplastic polymer matrix is used and the thermoplastic polymer powder is fluidizable.
• fluidisable means that the air flow rate applied to the fluidized bed is between the minimum fluidization flow rate (Umf) and the minimum bubbling flow rate (Umf) as represented in FIG. 17.
• the volume diameter D90 of the particles is 50 to 500 ⁇ , preferably 120 to 300 ⁇ .
• the volume diameter D10 of the particles is from 5 to 200 ⁇ , advantageously from 35 to 100 ⁇ .
• the average volume diameter of the thermoplastic polymer powder particles is between 30 and 300 ⁇ , in particular from 50 to 200 ⁇ , more particularly from 70 to 200 ⁇ .
• the volume diameters of the particles are defined according to ISO 9276: 2014.
• the "D50” corresponds to the average diameter by volume, ie the value of the particle size which divides the particle population examined in exactly two parts.
• the "D90” corresponds to the value at 90% of the cumulative curve of the particle size distribution in volume.
• the "D10" corresponds to the corresponds to the size of 10% of the particle volume.
• a creel is present before the vessel comprising a fluidized bed for controlling the tension of said wick or said wicks at the inlet of the vessel comprising a fluidized bed.
• one or more difficulties are present after the tank comprising the fluidized bed.
• the pre-impregnated wick (the parallel wicks), optionally covered with (s) a molten polymer, is (are) shaped into a single unidirectional ribbon or a plurality of parallel unidirectional ribbons, by means of a continuous calendering device comprising one or more heating calandres.
• the heating calenders of the calendering device are coupled to rapid heating means which make it possible to heat the material not only at the surface but also at the core.
• the wick blooming at the vessel outlet (20) comprising a fluidized bed (22) then shrinks under the effect of heating, which contributes to inserting the molten polymer between the fibers of the wick thereby reducing the porosity of said wick and promoting impregnation, particularly at the heart of said wick.
• the mechanical stress of the calenders coupled to these rapid heating means makes it possible to eliminate the presence of porosities and to homogeneously distribute the polymer, especially when the fibrous material is a so-called "ready-to-use" material.
• this hot calendering not only allows the impregnating polymer to be heated so that it penetrates, adheres and uniformly covers the fibers, but also to control the thickness and the width of the pre-fibrous material tape (s). -imginagné.
• the heating calenders in order to be able to produce a plurality of unidirectional parallel ribbons, that is to say as many ribbons as parallel strands pre-impregnated, passed in the fluidized bed, the heating calenders, referenced (51), (52), (53) in the diagram of Figure 1, advantageously comprise a plurality of grooves (73) calender, in accordance with the number of ribbons. This number of grooves can for example go up to 200.
• a SYST slave system also allows to regulate the pressure and / or spacing E between the rollers (71), (75) of the calender (70), so as to control the ep thickness of the ribbons.
• Such a shell (70) is shown schematically in Figure 2 described below.
• the calendering device comprises at least one heating radiator (51).
• it comprises several heating calandres (51), (52), (53) connected in parallel and / or in series with respect to the direction of travel of the fiber strands.
• the successive calendering step is carried out progressively with pressures between the rollers which are increasing (in the direction of travel of the process) and / or a spacing between the rollers which decreases (in the direction of travel of the process).
• each calender of the calendering device has an integrated heating system by induction or by microwaves, preferably by microwaves, in order to heat the polymer or mixture of thermoplastic polymers.
• the polymer or mixture of polymers comprises carbon-containing fillers, such as carbon black or carbon nanofillers, preferably chosen from carbon nanofillers, in particular graphenes and / or carbon nanotubes and / or carbon nanofibrils or their mixtures, the effect of heating by induction or by microwaves is amplified by the presence of these charges which then lead the heat to the heart of the material.
• each calender (51), (52), (53) of the device is coupled to a rapid heating device (41), (42), (43), located before and / or after each calender, in order to rapidly transmit thermal energy to the material and perfect the impregnation of the fibers with the molten polymer.
• the rapid heating device may for example be chosen from the following devices: a microwave or induction device, an IR or laser infrared device or other device allowing direct contact with the heat source such as a device with a flame or a hot gas.
• a microwave or induction device is very advantageous, in particular when it is coupled with the presence of carbon nanofillers in the polymer or polymer blend since carbon nanofillers amplify the heating effect and transmit it to the core of the material.
• the method may further comprise a step of heating the wicks of the fibers, prior to said impregnation with, as a preferred heating means, heating by microwaves as for the heating system of said heating shell.
• a subsequent step is to wind the precoated and shaped ribbon (s).
• the unit (100) for implementing the method comprises a winding device (60) comprising as many coils (61) as ribbons, a coil (61) being assigned to each ribbon.
• a splitter (62) is generally provided to deflect the pre-impregnated ribbons to their respective coils (61), while preventing the ribbons from touching to avoid any degradation.
• FIG. 2 shows schematically the detail of the grooves (73) of a calender (70) sectional view.
• a calender (70) includes an upper roller (71) and a lower roller (75).
• One of the rollers for example the upper roll (71), comprises a crenellated part (72), while the other roll, that is to say the lower roll (75) in the example, comprises a grooved part (76), the shape of the grooves being complementary to the shape of the projections (72) of the upper roll.
• the spacing E between the rollers (71), (75) and / or the pressure exerted by the two rollers against one another makes it possible to define the dimensions of the grooves 73), and in particular their thickness ep and width I.
• Each groove (73) is provided to house a fiber wick which is then pressed and heated between the rollers. The wicks then turn into parallel unidirectional ribbons whose thickness and width are calibrated by the grooves (73) of the calenders.
• Each calender advantageously comprises a plurality of grooves, the number of which can be up to 200, so as to produce as many ribbons as there are grooves and pre-impregnated locks.
• the calendering device further comprises a central device, referenced SYST in FIG. 1, controlled by a computer program provided for this purpose, which makes it possible to simultaneously regulate the pressure and / or the spacing of the calendering rollers of all the Unit 100 grilles.
• the unidirectional ribbon (s) thus manufactured has (s) a width I and a thickness ep adapted for robot removal in the manufacture of parts in three dimensions, without the need to be split at the good width.
• the width of the ribbon (s) is advantageously between 5 and 400mm, preferably between 5 and 50mm, and even more preferably between 5 and 15mm.
• the process for manufacturing a preimpregnated fibrous material which has just been described thus makes it possible to produce preimpregnated fibrous materials with high productivity, while permitting particularly high impregnation of the fibers and the control and reproducibility of the porosity, thus allowing control and reproducibility of the performance of the final composite article.
• the impregnation especially at the core around the fibers and the absence of porosities are ensured by the impregnation step in the tank by controlling the residence time in said powder, in particular a tank comprising a fluidized bed, and "effect of corner ", coupled with the simultaneous development of the wick at the compression roll or rolls.
• the materials obtained are semi-finished products in the form of ribbons calibrated in thickness and in width, and having a low porosity.
• the method thus makes it possible to produce calibrated ribbons of preimpregnated fibrous material suitable for the manufacture of composite parts in three dimensions, by automatically depositing said ribbons by means of a robot.
• thermoplastic polymer of the ribbon obtained with the process according to the invention is a polymer whose glass transition temperature is such that Tg> 80 ° C or a semicrystalline polymer whose melting temperature Tf> 150 ° C.
• thermoplastic polymer is:
• polyamide 6 PA-6
• PA-1 1 PA-1 1
• PA-12 polyamide 1 2
• PA-66 PA-66
• PA-46 polyamide 610
• PA-610 polyamide 612
• PA-1010 PA-1010
• PA-1012 polyamide 1012
• PA-1012 polyamide 1012
• copolyamides of these in particular 1010/1 1, 1010/12 etc ...
• an aromatic polyamide optionally modified with urea units, in particular a polyphthalamide, in particular a semi-aromatic polyamide of formula X / YAr, as described in EP1505099, in particular a semiaromatic polyamide of formula A / XT in which A is selected from a pattern obtained from an amino acid, a pattern obtained from a lactam and a pattern corresponding to the formula (diamine in Ca). (diacid in Cb), with a representing the number of carbon atoms of the diamine and b representing the number of carbon atoms of the diacid, a and b each being between 4 and 36, advantageously between 9 and 18;
• XT denotes a unit obtained from the polycondensation of a diamine in Cx and terephthalic acid, with x representing the number of carbon atoms of the diamine in Cx, x being between 6 and 36, advantageously between 9 and 18, in particular a polyamide of formula A 6T, A 9T, A 10T or A 1 1 T, A being as defined above, in particular a polyamide PA 6 / 6T, 66 / 6T, 6I / 6T, PA1 1 / 10T, 1 1 / 6T / 10T, MXDT / 10T or MPMDT / 10T, BACT / 10T aramid, and block copolymers, especially polyamide / polyether (PEBA).
• PEBA polyamide / polyether
• the fibrous material of the ribbon obtained with the process according to the invention is made of carbon fiber.
• thermoplastic polymer of the ribbon obtained with the process according to the invention is a semi-aromatic polyamide, in particular chosen from PA 1 1, PA 12, PA 1 1/1010, PA 12/1010, PA 1 1 / 10T, PA 1 1 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T and PA BACT / 10T and the fibrous material of the ribbon obtained with the process according to the invention is carbon fiber.
• said tape whose thermoplastic polymer is a polyamide chosen from PA 1 1, PA 12, PA 1 1/1010, PA 12/1010, PA 1 1 / 10T, PA 1 1 / 6T / 10T, PA MXDT / 10T, PA MPMDT / 10T and PA BACT / 10T is used for civil or military aeronautics or automotive.
• thermoplastic polymer of the ribbon obtained with the process according to the invention is PEKK.
• the fibrous material of the ribbon obtained with the process according to the invention is made of carbon fiber.
• thermoplastic polymer of the ribbon obtained with the process according to the invention is PEKK and the fibrous material of the ribbon obtained with the process according to the invention is made of carbon fiber.
• thermoplastic polymer of the ribbon obtained with the process according to the invention is PEI.
• the fibrous material of the ribbon obtained with the process according to the invention is made of carbon fiber.
• the thermoplastic polymer of the ribbon obtained with the process according to the invention is PEI and the fibrous material of the ribbon obtained with the process according to the invention is made of carbon fiber.
• thermoplastic polymer of the ribbon obtained with the process according to the invention is a mixture of PEKK and PEI, preferably 90-10% to 60-40%, in particular 90-10% to 70-30% by weight.
• the fibrous material of the ribbon obtained with the process according to the invention is made of carbon fiber.
• thermoplastic polymer of the ribbon obtained with the process according to the invention is a mixture of PEKK and PEI and the fibrous material of the ribbon obtained with the process according to the invention is made of carbon fiber.
• the present invention relates to the use of the ribbon of preimpregnated fibrous material, as defined above, in the manufacture of three-dimensional composite parts.
• said manufacture of said composite parts relates to the fields of transport, in particular automobile, oil and gas, in particular offshore, gas storage, civil or military aeronautical, nautical, railway; renewable energy, in particular wind turbine, tidal turbine, energy storage devices, solar panels; thermal protection panels; sports and recreation, health and medical, ballistics with weapon or missile parts, security and electronics.
• the present invention relates to a three-dimensional composite part, characterized in that it results from the use of at least one unidirectional tape of preimpregnated fibrous material as defined above.
• the fibrous material is chosen from carbon fiber and fiberglass.
• the thermoplastic polymer used to impregnate the carbon fiber is chosen from a polyamide, in particular an aliphatic polyamide such as PA 1 1, PA 12, PA 1 1/1010 or PA 12/1010, or a semi-aromatic polyamide, in particular especially a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T or a PA MPMDT / 10T, or PA BACT / 10T, PEKK and PEI or a mixture thereof.
• a polyamide in particular an aliphatic polyamide such as PA 1 1, PA 12, PA 1 1/1010 or PA 12/1010
• a semi-aromatic polyamide in particular especially a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T or a PA MPMDT / 10T, or PA BACT / 10T, PEKK and PEI or a mixture thereof.
• the thermoplastic polymer used to impregnate the glass fiber is chosen from a polyamide, especially an aliphatic polyamide such as PA 1 1, PA 12, PA 1 1/1010 or PA 12/1010, or a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, or PA BACT / 10T, PEKK and PEI or a mixture thereof.
• a polyamide especially an aliphatic polyamide such as PA 1 1, PA 12, PA 1 1/1010 or PA 12/1010, or a semi-aromatic polyamide, in particular a PA 1 1 / 10T, a PA 1 1 / 6T / 10T, a PA MXDT / 10T, a PA MPMDT / 10T, or PA BACT / 10T, PEKK and PEI or a mixture thereof.
• the level of fibers in said fibrous material is 45 to 65% by volume, preferably 50 to 60% by volume, in particular 54 to 60% by volume. .
• Table I groups advantageous embodiments according to the process of the invention carried out in a tank comprising a fluidized bed for a carbon fiber or glass fiber wick with one or more cylindrical compression rolls (s). ) not fluted:
• Polyamide glass 1 0.1 to 5 5 to 85
• Polyamide glass 1 0.1 to 5 5 to 45
• Polyamide glass 1 0.1 to 5 5 to 30
• Polyamide glass 1 0.1 to 3 5 to 85
• Polyamide glass 1 0.1 to 3 5 to 45
• Polyamide glass 1 0.1 to 3 5 to 30
• Polyamide glass 2 0.1 to 5 5 to 85
• Polyamide glass 2 0.1 to 5 5 to 45
• Polyamide glass 2 0.1 to 5 5 to 30
• Polyamide glass 2 0.1 to 3 5 to 85
• Polyamide glass 2 0.1 to 3 5 to 45
• Polyamide glass 2 0.1 to 3 5 to 30
• PEKK glass 1 0.1 to 5 5 to 85
• PEKK glass 1 0.1 to 5 5 to 45
• PEKK glass 1 0.1 to 5 5 to 30
• PEKK glass 2 0.1 to 5 5 to 85
• PEKK glass 2 0.1 to 5 5 to 45
• PEKK glass 2 0.1 to 3 5 to 85
• PEKK glass 2 0.1 to 3 5 to 45
• PEKK glass 2 0.1 to 3 5 to 30
• PEKK glass 3 0.1 to 5 5 to 30
• PEI glass 1 0.1 to 5 5 to 85
• PEI glass 1 0.1 to 5 5 to 45
• PEI glass 1 0.1 to 5 5 to 30
• PEI glass 1 0.1 to 3 5 to 85
• PEI glass 2 0.1 to 5 5 to 85
• PEI glass 2 0.1 to 5 5 to 45
• PEI glass 2 0.1 to 5 5 to 30
• PEI glass 2 0.1 to 3 5 to 85 1 19 Glass PEI 2 0.1 to 3 5 to 45
• the PEKK may be in admixture with PEI and the PEI may be in admixture with PEKK in the proportions defined above.
• the roller R2 is above the roller Ri relative to the bottom of the tank, in particular H2-H1 is from 1 cm to 30 cm, preferably from 1 to 10 cm, in particular from 1 cm to 3 cm, in particular about 2 cm and the angle O 2 is from 0 to 90 °, in particular from 25 to 45 ° C. in particular from 25 to 35 ° and the wick passes above R2.
• the roller R2 is above the roller Ri relative to the bottom of the tank, in particular H2-H1 is included from 1 cm to 30 cm, in particular about 2 cm and the angle O 2 is from 90 to 180 ° C, in particular from 1 to 135 °, especially from 1 to 125 °, and the lock passes below R2.
• the ratio D50 / average diameter of the unit fibers is from 3 to 15, in particular from 4 to 15.
• the ratio D50 / average diameter of the unit fibers is from 3 to 10, in particular from 4 to 10.
• the ratio D50 / average diameter of the unit fibers is from 10 to 40.
• the roller R2 is above the roller Ri relative to the bottom of the tank, in particular H2 -H1 is included from 1 cm to 3 cm, in particular about 2 cm and the angle o 2 is from 25 to 45 ° C, in particular from 25 to 35 ° and the wick goes above R2; and when the fiber material is fiberglass, then the ratio D50 / average diameter of the unit fibers is from 3 to 15, especially from 4 to 15, in particular from 3 to 10, in particular from 4 to 10.
• the roller R2 is above the roller Ri relative to the bottom of the tank, in particular H2-H1 is included from 1 cm to 3 cm, especially about 2 cm and the angle o 2 is from 80 to 45 ° C, in particular 60 to 45 ° and the wick goes below R2, and when the fibrous material is fiberglass, then the report
• the average diameter of the unit fibers is from 3 to 15, in particular from 4 to 15, in particular from 3 to 10, in particular from 4 to 10.
• the roller R2 is above the roller Ri relative to the bottom of the tank, in particular H2-H1 is included from 1 cm to 3 cm, in particular about 2 cm and the angle o 2 is from 25 to 45 ° C, in particular from 25 to 35 ° and the wick goes above R2; and when the fibrous material is carbon fiber, then the ratio D507 average diameter of the unit fibers is from 10 to 40.
• the roller R2 is above the roller Ri relative to the bottom of the tank, in particular H2-H1 is included from 1 cm to 3 cm, especially about 2 cm and the angle o 2 is from 80 to 45 ° C, in particular from 60 to 45 ° and the wick goes below R2, and when the fibrous material is carbon fiber, then the ratio D50 / average diameter of the unit fibers is from 10 to 40.
• Figure 1 shows a diagram of an implementation unit of the method of manufacturing a preimpregnated fibrous material according to the invention.
• Figure 2 shows a sectional diagram of two rollers constituting a calender as used in the unit of Figure 1.
• FIG. 3 details a tank (20) comprising a fluidized bed (22) with a height-adjustable, height-adjustable bartack (82).
• the edge of the tank inlet is equipped with a rotating roller 83a on which the wick 81a runs and the edge of the tank outlet is equipped with a rotary roller 83b on which the wick 81b runs.
• Fig. 4 shows a single-roll embodiment with a vessel (20) comprising a fluidized bed (22) in which a single cylindrical compression roll is present and showing the angle CM.
• the arrows at the fiber indicate the direction of travel of the fiber.
• FIG. 5 presents an embodiment, without being limited thereto, to two compression rolls R 1 and R 2, R 1 preceding R 2, with a vessel (20) comprising a fluidized bed (22) in which the two compression rollers cylinders are at different heights from the bottom of the tank (R2 to a height h above Ri at a height Hi) are present and showing the angle ai and 02.
• the arrows at the fiber wick indicate the direction of travel of the wick.
• FIG. 8 shows an exemplary embodiment with a vessel (20) comprising a fluidized bed (22) in which two cylindrical compression rolls R 1 and R 2, R 1 preceding R 2, at different levels are present and showing the angle CM and 02 and the wick passing under the roller R2.
• Figure 9 shows an embodiment with a vessel (20) comprising a fluidized bed (22) with two compression rollers R1 and R2, R1 preceding R2, and a compression roll R3 and showing the angles CM, 02 and 03.
• FIG. 10 shows a photograph taken under a scanning electron microscope of a sectional view of a 1 ⁇ 4 "carbon fiber wick (Toray fiber 12K T700S ⁇ 0 ⁇ , diameter 7 ⁇ ) impregnated with a polyamide PA PA MPTM / 10T powder.
• D50 1 15 ⁇ according to the process of the invention (as described in Example 2, after calendering).
• the image analysis gives a porosity of 5% excluding the edges of the tape.
• the ratio D50 / diameter 16.4.
• the ratio D50 / diameter 7.
• FIG. 14 shows a binocular photograph of a sectional view of a 1 ⁇ 2 "carbon fiber wick (SGL grade AA, 50K, diameter 7 ⁇ ) impregnated with a polyamide powder MPMDT / 10T of ⁇ ⁇ ⁇ ⁇ according to the process of the invention (as described in Example 4, after calendering).
• Figure 17 shows fluidization as a function of airflow.
• the air flow rate applied to the fluidized bed must be between the minimum fluidization flow rate (Umf) and the minimum bubbling flow rate (Umf)
• the ratio D50 / diameter 1.8, ie ⁇ 3.
• the results are shown in FIG. 15 (PA 1 1 example 1) and 16 (PA1 1 example 1a) show poor impregnation at heart, linked to the fact that the powder is too thin (and has a size distribution too narrow) to be properly fluidized. In particular, many instabilities are present in the fluidized bed (presence of bubbles) which disturb the impregnation process. In addition, in both examples (glass and carbon) the fiber wick expanded by the fluidized bed has difficulty retaining the powder because of its small particle size.
• Example 2 general procedure for impregnating a fibrous material (carbon fiber) with a polyamide powder in a fluidized bed with a single roll
• the fibrous material (1 ⁇ 4 "carbon fiber wick) was prepreged with a polyamide (PA 1 1 / 6T / 10T and MPMDT / 10T of defined particle size) were prepared according to this procedure and are presented in Figures 10 and 1 1.
• Figure 10 corresponds to the MPMDT / 10T, Figure 11 to PA 1 1 / 6T / 10T.
• Example 3 general procedure for impregnating a fibrous material (glass fiber) with a polyamide powder (PA11 and 11 / 6T / 10T) in a fluidized bed with a single roll
• the fibrous material (1200 tex fiberglass mesh) was preimpregnated with different polyamides (PA1 1 and 1 1 / 6T / 10T) according to this procedure and are shown in FIGS. 12 and 13.
• FIG. PA1 1 and Figure 13 to PA 1 1 / 61710T This demonstrates the effectiveness of the process of impregnation with a dry powder in a fluidized bed with a compression roll and control of the residence time in the powder.
• Example 4 general procedure for impregnating a fibrous material with a polyamide powder in a fluidized bed with two rollers
• the fibrous material (1 ⁇ 2 "carbon fiber wick) impregnated with a polyamide MPMDT / 10T) was prepared according to this procedure and is shown in FIG. 14 (binocular view).
• the impregnation rate is 40%.
• Porosity was determined by image analysis on a 1 ⁇ 2 "carbon fiber wick impregnated with MPMDT / 10T.) It is 5%.
• thermoplastic matrix The density of the thermoplastic matrix
• the weight of the reinforcement is the weight of the reinforcement:
• the number of samples must be at least 30 for the result to be representative of the studied material.
• Me ir ⁇ a mass of the sample measured in air.
• the variation of the mass ratio of fibers is supposed to be directly related to a variation of the matrix level without taking into account the variation of the quantity of the fibers in the reinforcement.
• the porosity is then the relative difference between theoretical density and experimental density.

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• 2016
  • 2016-12-22 FR FR1663209A patent/FR3061069B1/fr not_active Expired - Fee Related
• 2017
  • 2017-12-20 CN CN201780078449.1A patent/CN110099776A/zh active Pending
  • 2017-12-20 US US16/471,876 patent/US20200122359A1/en not_active Abandoned
  • 2017-12-20 WO PCT/FR2017/053730 patent/WO2018115738A1/fr unknown
  • 2017-12-20 KR KR1020197016931A patent/KR20190095291A/ko unknown
  • 2017-12-20 EP EP17829262.9A patent/EP3558613A1/fr not_active Withdrawn
  • 2017-12-20 JP JP2019534175A patent/JP2020501949A/ja active Pending

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