WO2021013769A1 - Method for manufacturing preforms for composite materials - Google Patents

Method for manufacturing preforms for composite materials Download PDF

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Publication number
WO2021013769A1
WO2021013769A1 PCT/EP2020/070386 EP2020070386W WO2021013769A1 WO 2021013769 A1 WO2021013769 A1 WO 2021013769A1 EP 2020070386 W EP2020070386 W EP 2020070386W WO 2021013769 A1 WO2021013769 A1 WO 2021013769A1
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WO
WIPO (PCT)
Prior art keywords
application
application support
station
fibrous
preform
Prior art date
Application number
PCT/EP2020/070386
Other languages
French (fr)
Inventor
Yves GARDET
Maxime KOWALSKI
Boris DUCHAMP
Original Assignee
Institut De Recherche Technologique Matériaux, Métallurgie, Procédés
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Filing date
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Application filed by Institut De Recherche Technologique Matériaux, Métallurgie, Procédés filed Critical Institut De Recherche Technologique Matériaux, Métallurgie, Procédés
Publication of WO2021013769A1 publication Critical patent/WO2021013769A1/en

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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
    • B29B11/00—Making preforms
    • B29B11/14—Making preforms characterised by structure or composition
    • B29B11/16—Making preforms characterised by structure or composition comprising fillers or reinforcement
    • 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
    • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
    • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
    • B29C70/28—Shaping operations therefor
    • B29C70/40—Shaping or impregnating by compression not applied
    • B29C70/42—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles
    • B29C70/46—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using matched moulds, e.g. for deforming sheet moulding compounds [SMC] or prepregs
    • B29C70/48—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using matched moulds, e.g. for deforming sheet moulding compounds [SMC] or prepregs and impregnating the reinforcements in the closed mould, e.g. resin transfer moulding [RTM], e.g. by vacuum
    • 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
    • B29C31/00—Handling, e.g. feeding of the material to be shaped, storage of plastics material before moulding; Automation, i.e. automated handling lines in plastics processing plants, e.g. using manipulators or robots
    • B29C31/04—Feeding of the material to be moulded, e.g. into a mould cavity
    • B29C31/08—Feeding of the material to be moulded, e.g. into a mould cavity of preforms to be moulded, e.g. tablets, fibre reinforced preforms, extruded ribbons, tubes or profiles; Manipulating means specially adapted for feeding preforms, e.g. supports conveyors

Definitions

  • the present invention relates to the field of composite materials, and in particular to the manufacture of fiber preforms for processes of the resin transfer molding type. State of the art
  • the resin transfer molding process or RTM (standing for “Resin Tranfer Molding” and its derivatives (including C-RTM, for “Compression Resin Transfer Molding") allow the production of high performance composite materials in large series while ensuring good repeatability Usually, the RTM process is broken down into two stages: the manufacture of a fiber preform;
  • the production of the fibrous preform, or preforming consists in shaping fibrous reinforcements to form a fibrous skeleton called a “preform” constituting a textile semi-product.
  • a particularity of the RTM process is that it uses dry fibers, the resin being added once the reinforcing structure - the preform - has been completely built.
  • the injection of resin (or impregnation) into the preform is carried out in a rigid and closed mold, in order to transform the preform into a composite part, by injection of resin and then polymerization of the latter.
  • Preforming which consists of transforming textile materials (fibers, rovings or semi-finished products composed of wicks) can be carried out via various processes.
  • the fibers applied may be continuous flat fibers, of the roving type, for example carbon fibers consisting of a multitude of carbon threads or filaments.
  • the so-called controlled pick-and-place processes in English "pick and place" in which semi-products such as fabrics or NCF (non crimp fabrics, or textiles without steaming in French) are deposited and shaped. .
  • Each of the material feeds resulting from these technologies is carried to the level of a compacting press (also called a forming press), typically by depositing the fibrous / textile materials directly into the compacting tool.
  • a compacting press also called a forming press
  • a binder is also deposited in the textile structure or the binder may be directly contained in the fibrous / woven material.
  • the fibrous assembly can be subjected to heat treatment.
  • the fibers tend to wrinkle, and this technique does not allow the production of preforms of complex shapes.
  • US 2014/0175709 discloses a process for manufacturing a shaped preform.
  • a flat blank is made of dry fibrous material containing binder.
  • the blank is placed between two flat flexible diaphragms (rubber, silicone, etc.).
  • the preform blank is placed in the compaction with raised surfaces. Forming takes place under controlled vacuum and with the application of heat, resulting in a three-dimensional preform with the desired fiber density.
  • Each of the known fiber application methods involves a number of advantages and constraints.
  • the manufacturer selects one of the methods according to the specifications (mechanical, economic, etc.) of the final composite part.
  • WO 2020/002408 describes a process for manufacturing fiber preforms.
  • the production unit comprises a fiber cutting unit, a preforming tool with a transport / deposit unit, a heating station and a preform cutting unit.
  • a robot 54 deposits the fibers of the cutting unit on the transport / deposit unit.
  • the transport / deposit unit is mobile and moves with the fibers to the heating station and the preform cutting unit.
  • FR B 008 642 there is described a process for injection molding of composite parts, in which a fiber preform is 'consolidated' before injection of consolidation resin into a 'consolidation' tool, by applying a compacting pressure and by heating. the consolidation tool.
  • the object of the present invention is to provide an improved process for manufacturing fiber preforms.
  • the invention arises from the need to be able to combine in an operationally efficient manner 2 or 3 fiber application technologies, to obtain a so-called hybrid preform.
  • a preforming tool is generally a solid steel tool that can weigh up to a few tens of tons and is thermo-regulated by heat transfer fluids. For logistics issues (movement of large masses, fluid connection, energy consumption, etc.) this solution is not possible in a context of large-scale production.
  • the invention proposes the use of a so-called “application support” media defining an application surface on which the fibrous materials will be deposited, and which supports the assembly / the fibrous deposit during the process. application of the fibrous material as well as during the subsequent stages, and in particular during compaction.
  • the invention relates to a method of manufacturing a fiber preform for a composite comprising: providing an application support, movable, defining an application surface; a fibrous material application phase comprising: positioning the application support at at least one fiber application station, and
  • a compacting (or forming) phase comprising: positioning of the application support at a station for compacting the fibrous structure
  • the application support being placed, with the fibrous deposit, between the compacting tools and supporting the fibrous deposit during compaction, extraction of the application support and of the fiber preform obtained.
  • the fiber preform obtained can advantageously be supported by the application support.
  • the application support is said to be “mobile” in the sense that it can be moved from a station for applying fibrous materials to the compacting station, and in general between the different stations.
  • the application support is particularly advantageous for the hybridization of the preform, that is to say when it is desired to combine several fiber application technologies, in particular before a single and unique compacting phase.
  • the application support is moved near each fiber application station to form a hybrid deposit, which will be compacted at one time.
  • the application support is not a simple tool for transferring fiber structure blanks.
  • the fibrous materials are applied, at each application station, in contact, that is to say directly on the application surface of the application support and / or on the fibers already deposited in the application. previous application post.
  • the application support will advantageously have a three-dimensional shape taking up all or part of the geometry of the preform to be produced, taking into account the specificities of the fiber / textile structure (s) used (thicknesses, expansion, etc.).
  • the application support can be substantially flat, when flat preforms are desired.
  • the application support therefore constitutes a sort of three-dimensional plate which travels with the fibrous assembly, accompanying it during its formation and during compaction. It can also be called a “thin skin” because it takes up little space since it has a shape corresponding to the geometry of the desired preform.
  • the application support may for example consist of a set of substantially flat sections (forming panels), the geometries of which may be similar or vary, located in one or more panels, optionally completed by curved panels and / or openings for receiving movable mold parts.
  • the application support is also typically reusable, that is to say that it will be used in several cycles of manufacturing fiber preforms.
  • the application support is made of a polymer-based material, in particular of a fiber / polymer-based composite material.
  • the thickness of the application support generally depends on the choice of the composite material which constitutes it, and is also a function of the envisaged application, itself conditioning the mass, thermal inertia, rigidity, temperature behavior. , etc. Those skilled in the art will therefore choose an appropriate material for the application support, depending on the intended use.
  • the material of the application support is preferably chosen to have a certain rigidity which allows its shape to be retained.
  • a carbon / epoxy type composite will be preferred for the application support.
  • a carbon / BMI composite can be used for the application support.
  • the application support can have a thickness between 1 and 5 mm.
  • the thickness of the application support may be constant over its entire extent, or vary locally.
  • the material constituting the application support is advantageously chosen to be compatible with a potential preheating operation necessary for the activation of certain binders, in particular to ensure control of the geometry (controlled thermal expansion) over the temperature range 50 to 200 ° C.
  • the compaction phase includes heating the compaction tools.
  • the application support can advantageously be functionalized to take into account various aspects of the process for manufacturing the preform, respectively the composite. According to the variants, the application support is configured to allow the maintenance / relaxation / sliding of one or more textile structures during the different phases of the process.
  • the maintenance of textile structures is an aspect that results from the potential deformation or movement of the textile / fiber reinforcements during the transitic phases.
  • the relaxation of the textile must take place before the shaping step in order to be able to allow the textile to deform and swallow without constraints (except geometric).
  • These two “hold / release” operations can be performed by retention means integrated into the application support, which can be called “line grippers” in English.
  • the retention means can be designed to allow their actuation during the transitic phases and be deactivated / retracted during the shaping phase.
  • the retention means can take the form of a set of retractable needles mounted at one or more locations on the application support. The needles are kept protruding or retracted by a suitable mechanism. In the active configuration, these needles protrude and allow the fibrous deposit to be retained.
  • the retention means are configured to be deactivatable by the tools of the compacting station or by the displacement / gripping means.
  • the application face of the application support may comprise a non-stick surface treatment, in particular of the metallization or Teflon type.
  • a non-stick coating makes it possible to deal with the theme of sliding of textile / fibrous structures (which will allow their controlled swallowing, deformation during shaping).
  • pinouts spacing of fibers to allow an absence of material locally
  • Means compatible with the different movements of the pins and their kinematics will therefore be advantageously provided.
  • the application support could integrate a heating means, which can take the form of resistive heating lines, supplied by an outside source.
  • This heating means can be used for thermal activation of the binder, on all or part of the surface of the application support.
  • the application support can comprise all kinds of non-fibrous inserts, linked to the functionalities that one wishes to provide for the preform.
  • These inserts can be fixing elements or for the passage of material, for example stakes, cylinders or pins.
  • the inserts can also be sensors, for example mechanical stress sensor or RFID chip (by way of example, the dimensions of such sensors can be 50 * 20mm 2 or 30 * 30mm 2 or others).
  • the application support is advantageously designed to take into account the need for interfacing with the forming tool (compacting station). Indeed, since the application support is intended to be used in the production cycle, it will undergo loading / unloading cycles between the compaction tools.
  • the application support will therefore advantageously comprise referencing or centering means (for example through orifices, bosses or the like) cooperating with corresponding means in the compacting station. This makes it possible to guarantee positioning reproducibility at the level of the contact zones identified for its support.
  • the interfacing it is also desirable for the interfacing to allow the compressive forces exerted by the mold to be taken up on the application support.
  • the latter must be homogenized over the entire surface of the application support. Indeed, the application support by its constituents will typically have an elastic behavior for low deformations. To ensure that the 3D dimensions of the preform are respected, it is desirable to limit these elastic effects.
  • This homogenization can be ensured by functionalization of the tool by using, for example, areas of elastomers placed on the walls of the compression tools, the characteristics of which, in particular of positioning, hardness, or others, are chosen to homogenize the compressive forces. .
  • the means for referencing or centering the application support can be used for interfacing with the other stations, in particular stations for applying fibrous materials.
  • Other referencing / centering means could also be provided in the application support.
  • the application support can be designed to be the lower molding surface of the preform.
  • the application surface of the application support is structured to correspond partially or entirely to the desired shape of the preform.
  • the surface condition of the application support is produced to allow easy “release” of the preform.
  • the term “fibrous material” is understood to mean all kinds of materials composed of fibers or filaments, individual or in the form of rovings or sheets, structured (woven, braided, NCF) or not, also including all kinds of textiles.
  • the fibrous materials used in the context of the invention are suitable for forming, in the form in which they are applied or following their assembly on the application support, a fibrous reinforcement for a composite part.
  • the fibrous material is a raw fibrous material, optionally containing a binder.
  • the fibrous material comprises sub-preforms, that is to say fibrous / textile structures already compacted and / or shaped.
  • the application support therefore allows the deposition and assembly, in a complementary and / or stacked manner, of all kinds of fibers and textiles, as well as existing preforms, and their combination.
  • the compacting station can be of any type suitable for imparting its final shape or geometry to the preform.
  • the deposit or fibrous assembly is coherent and self-supporting.
  • the compaction station is generally designed as a press for compaction, stamping or stamping.
  • the compaction station generally comprises two tools (or molds) facing each other, movable towards one another, and having molding surfaces with complementary shapes, configured according to the shape of the desired preform.
  • the configuration of the tools is often three-dimensional, but it is possible to make flat preforms.
  • each tool may include independent mobile mold sub-parts, depending on the complexity of the 3D shapes to be achieve.
  • the application support constitutes a means of support of fibrous / textile assemblies whose handling and use are simple, and which allows compaction at ambient pressure, without the use of vacuum, for example in the solution of US 2014/0175709 .
  • the fiber application station (s) are work stations where fibrous materials are deposited on the application surface of the application support.
  • the material is deposited by any suitable technique, by hand by an operator or preferably in an automated manner, for example by application heads.
  • the present method is applicable with application stations operating according to known techniques. In practice, the fibrous materials are deposited directly against the application surface but for subsequent passes, fibrous materials can be deposited on a prior deposit, thus forming an assembly of fibrous materials.
  • the application stations may be of the type: fiber projection station, fiber placement station or station for depositing textile semi-products.
  • fiber materials will typically be deposited according to at least two different technologies, and therefore at the level of at least two distinct and separate fiber application stations.
  • the deposited fibrous material may contain a binder and / or a binder may be added, ie deposited on the application surface and / or on the fibrous materials, at the application stations or at a station. binder deposit.
  • a binder can be activated (polymerization) thermally or by photopolymerization.
  • the method may include a trimming step at a trimming station, in order to remove the excess material from the preform, and therefore to make it "net-shape".
  • the application support can also be used to support the preform during trimming. Alternatively, the trimming can be performed after separation of the preform from its application support.
  • the present invention has been developed in the context of the textile preforming process. However, the invention can be applied and / or transposed to other processes for the production of composites and can be generalized to all types of dry fiber / textile structures with or without reactive binders, whatever the application processes.
  • the invention also relates to a method of manufacturing a composite part comprising the following steps:
  • the invention relates to a system for manufacturing a composite part suitable for implementing the present method, comprising: at least one station for applying fibrous material; an application support defining an application surface; an optional preheating station; a compacting station configured to compact the fibrous material resting on the application support (12) between two tools having complementary molding faces; and means for moving the application support between the different stations.
  • the system includes one or more of the following features:
  • an injection station comprising two tools configured to define a molding cavity for receiving the preform resting on the application support and means for introducing a liquid polymer material into the molding cavity;
  • the application support comprises means for retaining fibrous deposits;
  • the application support comprises centering means able to cooperate with corresponding means provided in the application stations or in the compacting station or at the level of the gripping / displacement means of the application support.
  • FIG. 1 a principle view of the system for manufacturing fiber preforms, according to one embodiment of the invention
  • FIG. 2 a diagram illustrating the steps of the present method, with a system of the type of FIG. 1;
  • FIG. 1 represents a principle view of the system 10 for manufacturing fiber preforms according to the invention.
  • the system comprises: an application support 12 with an application face 12.1;
  • first fibrous material application station 14 eg. of the “pick and place” type
  • a second fibrous material application station 16 e.g. of the fiber projection type
  • This system is remarkable in that it uses a mobile and reusable application support 12, for the deposit of fibrous materials and their support as well as a robot.
  • manipulator 24 able to move in the system so as to move / manipulate the application support 12 between the different stations.
  • Robot 22 is just one example. Any kind of gripping and displacement means can be used for the application support 12 allowing the displacement of the application support 12 and the installation of the latter in the various stations. It is also possible to have a combination of manipulating robots, possibly with conveyors.
  • the stations 14 to 22 are, for their operating principle, known as such and are not the subject of the invention; they will therefore not be described in detail.
  • the reference sign 26 designates an injection station which allows the resin to be impregnated, by injection, in accordance with an RTM process.
  • Such an injection station comprises two rigid molding tools which define between them a cavity (or an air gap) configured to receive the preform.
  • the system 10, associated with the injection station 26, forms a system for the production of composite parts.
  • the application support 12 can be functionalized in order to provide for various problems of its use.
  • the application support can in particular comprise one or more of the following characteristics: referencing means, which can take the form of through openings, bosses, or the like, making it possible to facilitate the handling and / or referencing of the application support , that is to say the relative positioning of the application support with the tools of the different stations, and / or its handling / gripping by the robot or other means of handling / displacement of the application support
  • non-stick coating eg. metallization, teflon or equivalent, to facilitate the sliding of the fibrous folds
  • the retention means are preferably selectively operable.
  • the means of retention of fibrous deposits are preferably designed to be deactivatable, manually or automatically, during installation of the application support in the lower tool of the compaction station.
  • the retention means may comprise one or more sets of needles distributed in one or more regions of the application support. The needles are mounted in a retractable manner on the application support, so as to be by default projecting on the application surface, and automatically retracted when the tools of the compacting station are closed.
  • Fig. B shows a principle view of a variant of the preform 12.
  • the preform is a three-dimensional rectangular part.
  • the upper face 12.1 is an application face for fibrous materials.
  • the preform is shaped in three sections distributed in the length.
  • Reference sign 12.3 designates an opening in the first two sections (starting from the left) for the passage of a molding tool (see below).
  • the reference sign 12.4 designates two series of retractable hooking needles forming the gripper lines.
  • two centering holes 12.5 are provided for interfacing with the lower tool of the compaction station.
  • the dotted line 12.6 symbolizes resistive heating lines incorporated in the body of the application support 12.
  • the 3 sides of the application support 12 are substantially flat, with a small thickness, typically between 1 and 5 mm.
  • the application medium can be made from plies of carbon prepreg (approximately 1600 to 2000 g / m 2 ). The resistance is good for a service temperature up to 180 ° C.
  • the application support 12 used in the process can be recognized, the upper face of which, called the application surface 12.1, is intended to receive the fibrous materials at one or more fiber application stations.
  • the application support 12 is advantageously functionalized as in Fig.3.
  • the fibrous materials are deposited on the application support 12 during the application phase (Fig. 2b).
  • One or more layers of fibrous materials are deposited on the application face 12.1, and this at one or more fiber application stations.
  • the application support is positioned in a first application station for the deposition of fibrous material according to a first technology, for example projection of fibers 16.
  • One or more layers of fibers 42 can be formed.
  • application support can be moved to the next phase.
  • the particular advantage of the application support 12 is that it makes it possible to combine the technologies for depositing fibrous material.
  • the application support can therefore advantageously be moved / positioned and installed in another application station, for example of the “pick and place” type. In this station, folds of textile webs are then deposited on the layer or layers of fibrous material deposited at the first application station.
  • the deposited fibrous material may contain a binder and / or a binder may be added, ie deposited on the application surface and / or on the fibrous materials, at the application stations or at a station. binder deposit.
  • the application support which travels with the deposits of fibrous materials produced on its application face 12.1, will thus make it possible to easily combine the application technologies, to obtain a “hybrid” preform.
  • the deposit (s) of fibrous material 17 produced at one or more application stations are called deposits, sets or fibrous assemblies.
  • the retention needles 12.4 are preferably active.
  • the next optional phase is the preheating phase.
  • the fibrous assembly 17 of the application phase, supported by the application support 12, is subjected to a heat treatment (Fig.2c).
  • a heat treatment Fig.2c
  • the application support 12 with the fibrous assembly 44 (resulting from the application of fibers according to one or more technologies) is placed in a static or tunnel oven 18 (conveyor) to heat the fibrous assembly and soften the binder. and / or start the polymerization process.
  • the application support 12 is positioned at the level of the compaction station 20, in order to operate the compaction phase.
  • This comprises a press with two tools 20.1 arranged face to face, typically one above the other.
  • the two tools are rigid and have facing molding faces, complementary to each other.
  • Each tool 20.1 can be made up of several mold parts which can be moved independently.
  • the dotted line at the level of the upper tool 20.1 represents a central cavity 20.2 which receives a part of the mold, called a “punch” which projects out of the lower tool 20.1, and passes through an opening in the application support, such as opening 12. B.
  • the compaction begins with the positioning (installation) of the application support with the fibrous deposit on the lower molding face (dl), then the upper tool 20.1 is lowered (d2).
  • One of the sets of retention pins 12.4 is preferably deactivated prior to closing to allow some sliding of the fibrous material.
  • the two tools 20.1 are configured to approach each other in a complementary manner, in a configuration corresponding to the shape desired for the preform. Compaction is controlled to achieve the desired fiber density. This is the configuration of Fig. 2 d3). It is in this closed configuration that the punch is deployed through the opening 12.3.
  • the press is then opened (the tools are removed, cf. Fig. 2 d4) and the preform thus obtained, indicated 46 in contrast to the fibrous assembly 44, can be extracted.
  • the preform 46 and the application support 12 can be extracted separately.
  • the application support 12 is particularly interesting because it allows easy extraction of the preform 46. Instead of directly handling the preform, it is easier to grip the application support 12, which supports the preform 46.
  • the preform 46 is placed in an injection mold 26 which comprises two mold parts 26.1 of complementary shape and defining a mold cavity 26.2 in which the preform 46 is placed.
  • the preform 46 can be installed alone in the injection mold 26 but is in Figure 2 e) supported by the application support 12.
  • a resin, contained in a heating tank 26.4, is introduced, via a channel 26. B, in the mold cavity 26.2.
  • the mold 26 is heated to the temperature required for the polymerization.
  • the mold is then opened and the composite extracted.
  • the presence of the application support 12 facilitates demolding.

Abstract

The present invention concerns a system and method for manufacturing a fibrous preform for a composite. The system comprises at least one fibrous material application station (14, 16); an optional pre-heating station (18); a compacting station (20). The system further comprises an application support (12) defining an application surface (12.1), on which the fibrous materials are deposited at one or more application stations, before compacting the fibrous materials resting on the application support (12) between the tools (20.1) of the compacting station. Means (24) are provided for moving the application support (12) between the different stations.

Description

Procédé de fabrication de préformes pour matériaux composites Manufacturing process of preforms for composite materials
La présente invention concerne le domaine des matériaux composites, et en particulier la fabrication de préformes fibreuses pour des procédés du type moulage par transfert de résine. Etat de la technique The present invention relates to the field of composite materials, and in particular to the manufacture of fiber preforms for processes of the resin transfer molding type. State of the art
Le procédé de moulage par transfert de résine, ou RTM (de l'anglais « Resin Tranfer Moulding » et ses dérivés (dont le C-RTM, pour « Compression Resin Transfer Molding ») permettent la production de matériaux composites hautes performances en grande série tout en garantissant une bonne répétabilité. Habituellement, le procédé RTM est décomposé en deux étapes : la fabrication d'une préforme fibreuse ; The resin transfer molding process, or RTM (standing for "Resin Tranfer Molding" and its derivatives (including C-RTM, for "Compression Resin Transfer Molding") allow the production of high performance composite materials in large series while ensuring good repeatability Usually, the RTM process is broken down into two stages: the manufacture of a fiber preform;
l'injection de résine dans la préforme fibreuse. injecting resin into the fiber preform.
La réalisation de la préforme fibreuse, ou préformage, consiste à mettre en forme des renforts fibreux pour former un squelette fibreux appelé « préforme » constituant un semi-produit textile. Une particularité du procédé RTM est qu'il utilise des fibres sèches, l'apport de résine se faisant une fois la structure de renfort -la préforme- entièrement construite. L'injection de résine (ou imprégnation) dans la préforme est réalisée dans un moule rigide et fermé, afin de transformer la préforme en une pièce composite, par injection de résine puis polymérisation de celle-ci. Le préformage, qui consiste à transformer des matières textiles (fibres, mèches ou semi-produits composés de mèches) peut être réalisé via différents procédés. The production of the fibrous preform, or preforming, consists in shaping fibrous reinforcements to form a fibrous skeleton called a “preform” constituting a textile semi-product. A particularity of the RTM process is that it uses dry fibers, the resin being added once the reinforcing structure - the preform - has been completely built. The injection of resin (or impregnation) into the preform is carried out in a rigid and closed mold, in order to transform the preform into a composite part, by injection of resin and then polymerization of the latter. Preforming, which consists of transforming textile materials (fibers, rovings or semi-finished products composed of wicks) can be carried out via various processes.
On connaît des procédés de réalisation de préformes tridimensionnelles par projection de fibres, éventuellement associées à un liant. Les fibres déroulées depuis des bobines sont acheminées jusqu'à une tête de projection dans laquelle les fibres sont coupées par des couteaux rotatifs en segments de 10 à 50 mm, par exemple. La tête est montée à l'extrémité d'un bras robotisé pour faire une projection en continu de fibres coupées sur l'outillage telle qu'une surface moulante inférieure. Un tel procédé est par exemple décrit dans le EP 1 250 991. On connaît également des procédés dits de placement de fibres dans lesquels des fibres continues sont déposées au contact sur un outillage pour former plusieurs plis dans des orientations définies. Ce procédé d'application au contact est mis en œuvre au moyen d'une tête d'application de fibres comportant un rouleau d'application destiné à venir en contact contre l'outillage pour appliquer une bande formée d'une ou plusieurs fibres plates continues, et un système de guidage pour guider la ou les fibres sur ledit rouleau. Les fibres appliquées peuvent être des fibres plates continues, de type mèches, par exemple des fibres de carbone constituées d'une multitude de fils ou filaments de carbone. On connaît encore les procédés dits prise et dépose contrôlées (en anglais « pick and place ») dans lequel on vient déposer et mettre en forme des semi-produits tels que des tissus ou NCF (non crimp fabrics, ou textiles sans embuvage en français). There are known methods for producing three-dimensional preforms by spraying fibers, optionally associated with a binder. The fibers unwound from spools are conveyed to a projection head where the fibers are cut by rotary knives into segments of 10 to 50 mm, for example. The head is mounted at the end of a robotic arm to continuously project cut fibers onto tooling such as a bottom molding surface. Such a process is for example described in EP 1 250 991. Also known are so-called fiber placement methods in which continuous fibers are deposited in contact on a tool to form several folds in defined orientations. This contact application method is implemented by means of a fiber application head comprising an application roller intended to come into contact against the tool to apply a strip formed of one or more continuous flat fibers. , and a guide system for guiding the fiber or fibers on said roll. The fibers applied may be continuous flat fibers, of the roving type, for example carbon fibers consisting of a multitude of carbon threads or filaments. We also know the so-called controlled pick-and-place processes (in English "pick and place") in which semi-products such as fabrics or NCF (non crimp fabrics, or textiles without steaming in French) are deposited and shaped. .
Chacune des alimentations en matière issues de ces technologies est conduite au niveau d'une presse de compactage (dite aussi de formage), typiquement en déposant les matériaux fibreux/textiles directement dans l'outillage de compactage. Each of the material feeds resulting from these technologies is carried to the level of a compacting press (also called a forming press), typically by depositing the fibrous / textile materials directly into the compacting tool.
Selon les variantes, on dépose également un liant (« binder » en anglais) dans la structure textile ou le liant peut être directement contenu dans le matériau fibreux/tissé. Selon les cas de figure, l'assemblage fibreux peut être soumis à un traitement thermique. Afin d'augmenter les cadences, il a été proposé d'appliquer au contact les fibres sur un outillage de drapage sensiblement plan, puis de transférer l'ensemble des plis entre les outillages mâle et femelle (respectivement poinçon et matrice) d'une presse pour obtenir la préforme avec sa forme finale souhaitée. Suivant la forme de la préforme finale, les fibres ont tendance à se plisser, et cette technique ne permet pas la réalisation de préformes de formes complexes. According to the variants, a binder is also deposited in the textile structure or the binder may be directly contained in the fibrous / woven material. Depending on the circumstances, the fibrous assembly can be subjected to heat treatment. In order to increase the rates, it has been proposed to apply the fibers in contact on a substantially flat draping tool, then to transfer all the folds between the male and female tools (punch and die respectively) of a press. to obtain the preform with its desired final shape. Depending on the shape of the final preform, the fibers tend to wrinkle, and this technique does not allow the production of preforms of complex shapes.
Le US 2014/0175709 divulgue un procédé de fabrication de préforme façonnée. On fabrique d'abord une ébauche plane de matériau fibreux sec, contenant du liant. Dans le procédé, l'ébauche est placée entre deux diaphragmes plans et flexibles (caoutchouc, silicone, etc.). L'ébauche de préforme est placée dans l'outil de compactage avec des surfaces en relief. Le formage a lieu sous vide contrôlé et avec application de chaleur, permettant d'obtenir une préforme tridimensionnelle avec la densité fibreuse souhaitée. US 2014/0175709 discloses a process for manufacturing a shaped preform. First, a flat blank is made of dry fibrous material containing binder. In the process, the blank is placed between two flat flexible diaphragms (rubber, silicone, etc.). The preform blank is placed in the compaction with raised surfaces. Forming takes place under controlled vacuum and with the application of heat, resulting in a three-dimensional preform with the desired fiber density.
Chacune des méthodes d'application de fibres connues implique un certain nombre d'avantages et de contraintes. L'industriel sélectionne l'une des méthodes en fonction du cahier des charges (mécaniques, économiques, etc...) de la pièce composite finale. Each of the known fiber application methods involves a number of advantages and constraints. The manufacturer selects one of the methods according to the specifications (mechanical, economic, etc.) of the final composite part.
Le WO 2020/002408 décrit un procédé de fabrication de préformes fibreuses. L'unité de production comprend une unité de découpe de fibres, un outil de préformage avec une unité de transport/dépose, une station de chauffage et une unité de découpe de préformes. Un robot 54 dépose les fibres de l'unité de découpe sur l'unité de transport/dépose. L'unité de transport/dépose est mobile et se déplace avec les fibres vers la station de chauffage et l'unité de découpe de préformes. WO 2020/002408 describes a process for manufacturing fiber preforms. The production unit comprises a fiber cutting unit, a preforming tool with a transport / deposit unit, a heating station and a preform cutting unit. A robot 54 deposits the fibers of the cutting unit on the transport / deposit unit. The transport / deposit unit is mobile and moves with the fibers to the heating station and the preform cutting unit.
Dans le FR B 008 642 on décrit un procédé de moulage par injection de pièces composites, dans lequel une préforme fibreuse est 'consolidée' avant injection de résine de consolidation dans un outillage 'de consolidation', en appliquant une pression de compactage et en chauffant l'outil de consolidation. In FR B 008 642 there is described a process for injection molding of composite parts, in which a fiber preform is 'consolidated' before injection of consolidation resin into a 'consolidation' tool, by applying a compacting pressure and by heating. the consolidation tool.
Description Générale de l'invention General description of the invention
L'objet de la présente invention est de proposer un procédé amélioré de fabrication de préformes fibreuses. L'invention découle du besoin de pouvoir combiner de manière opérationnellement efficace 2 ou 3 technologies d'application de fibres, pour obtenir une préforme dite hybride. The object of the present invention is to provide an improved process for manufacturing fiber preforms. The invention arises from the need to be able to combine in an operationally efficient manner 2 or 3 fiber application technologies, to obtain a so-called hybrid preform.
Dans l'état de la technique, de manière classique, l'industriel sélectionne l'un des procédés d'application de fibres, en fonction du cahier des charges de la pièce composite finale, nécessitant chacun des infrastructures particulières. A ce jour, il n'existe pas de solution efficace permettant de combiner (hybrider) ces procédés pour la réalisation d'une préforme. Une solution possible d'hybridation résiderait dans le fait de déplacer l'outillage de préformage de poste en poste, avec potentiellement une adaptation de sa température aux besoins, généralement différents, de chacun des procédés d'application. Un outillage de préformage est généralement un outillage en acier massif pouvant peser jusqu'à quelque dizaines de tonnes et est thermo-régulé par fluides caloporteurs. Pour des questions de logistique (déplacement de masses importantes, branchement fluides, consommation énergétique, etc..) cette solution n'est pas envisageable dans un contexte de production à grande échelle. Dans ce contexte, l'invention propose l'utilisation d'un media dit « support d'application » définissant une surface d'application sur laquelle on va venir déposer les matériaux fibreux, et qui supporte l'assemblage/le dépôt fibreux pendant l'application du matériau fibreux ainsi que pendant les phases ultérieures, et notamment pendant le compactage. Selon un premier aspect, l'invention concerne un procédé de fabrication d'une préforme fibreuse pour un composite comprenant : la fourniture d'un support d'application, mobile, définissant une surface d'application ; une phase d'application de matériau fibreux comprenant : positionnement du support d'application au niveau d'au moins un poste d'application de fibres, et In the state of the art, conventionally, the manufacturer selects one of the methods of applying fibers, according to the specifications of the final composite part, each requiring specific infrastructures. To date, there is no effective solution for combining (hybridizing) these processes for the production of a preform. One possible hybridization solution would reside in moving the preforming tool from station to station, potentially adapting its temperature to the generally different needs of each of the application methods. A preforming tool is generally a solid steel tool that can weigh up to a few tens of tons and is thermo-regulated by heat transfer fluids. For logistics issues (movement of large masses, fluid connection, energy consumption, etc.) this solution is not possible in a context of large-scale production. In this context, the invention proposes the use of a so-called “application support” media defining an application surface on which the fibrous materials will be deposited, and which supports the assembly / the fibrous deposit during the process. application of the fibrous material as well as during the subsequent stages, and in particular during compaction. According to a first aspect, the invention relates to a method of manufacturing a fiber preform for a composite comprising: providing an application support, movable, defining an application surface; a fibrous material application phase comprising: positioning the application support at at least one fiber application station, and
application d'au moins un matériau fibreux sur la surface d'application du support d'application ; une phase de compactage (ou formage) comprenant : positionnement du support d'application au niveau d'un poste de compactage de la structure fibreuse, applying at least one fibrous material to the application surface of the application support; a compacting (or forming) phase comprising: positioning of the application support at a station for compacting the fibrous structure,
compression du dépôt fibreux dans le poste de compactage, le support d'application étant placé, avec le dépôt fibreux, entre les outils de compactage et supportant le dépôt fibreux pendant le compactage, extraction du support d'application et de la préforme fibreuse obtenue. Lors de l'extraction, la préforme fibreuse obtenue peut être avantageusement supportée par le support d'application. compression of the fibrous deposit in the compacting station, the application support being placed, with the fibrous deposit, between the compacting tools and supporting the fibrous deposit during compaction, extraction of the application support and of the fiber preform obtained. During extraction, the fiber preform obtained can advantageously be supported by the application support.
Le support d'application est dit « mobile » en ce sens qu'il peut être déplacé d'un poste d'application de matériaux fibreux au poste de compactage, et de manière générale entre les différents postes. Le support d'application est particulièrement intéressant pour l'hybridation de la préforme, c'est-à-dire lorsqu'on souhaite combiner plusieurs technologies d'application de fibres, notamment avant une seule et unique phase de compactage. Dans ce cas, le support d'application est déplacé auprès de chaque poste d'application de fibres pour former un dépôt hybride, qui sera compacté en une seule fois. The application support is said to be “mobile” in the sense that it can be moved from a station for applying fibrous materials to the compacting station, and in general between the different stations. The application support is particularly advantageous for the hybridization of the preform, that is to say when it is desired to combine several fiber application technologies, in particular before a single and unique compacting phase. In this case, the application support is moved near each fiber application station to form a hybrid deposit, which will be compacted at one time.
On appréciera ici que le support d'application n'est pas un simple outil de transfert d'ébauches de structures fibreuses. Dans le procédé, les matériaux fibreux sont appliqués, au niveau de chaque poste d'application, au contact, c'est-à-dire directement sur la surface d'application du support d'application et/ou sur les fibres déjà déposées au poste d'application précédent. It will be appreciated here that the application support is not a simple tool for transferring fiber structure blanks. In the process, the fibrous materials are applied, at each application station, in contact, that is to say directly on the application surface of the application support and / or on the fibers already deposited in the application. previous application post.
Le support d'application aura avantageusement une forme tridimensionnelle reprenant tout ou partie de la géométrie de la préforme à réaliser, en tenant compte des spécificités de ou des structures fibreuses/textiles utilisées (épaisseurs, foisonnement, etc.). Alternativement le support d'application peut être sensiblement plan, lorsque des préformes planes sont souhaitées. The application support will advantageously have a three-dimensional shape taking up all or part of the geometry of the preform to be produced, taking into account the specificities of the fiber / textile structure (s) used (thicknesses, expansion, etc.). Alternatively, the application support can be substantially flat, when flat preforms are desired.
Le support d'application constitue donc une sorte de plateau tridimensionnel qui voyage avec l'ensemble fibreux, l'accompagnant pendant sa formation et pendant le compactage. On peut aussi l'appeler « peau mince », car il est peu encombrant puisqu'il a une forme correspondant à la géométrie de la préforme désirée. Le support d'application peut par exemple être constitué d'un ensemble de sections sensiblement planes (formant des pans), dont les géométries peuvent être similaires ou varier, situées dans un ou plusieurs pans, optionnellement complété par des pans incurvés et/ou des ouvertures pour recevoir des parties de moule mobiles. Le support d'application est aussi typiquement réutilisable, c'est-à-dire qu'on va l'utiliser dans plusieurs cycles de fabrication de préformes fibreuses. The application support therefore constitutes a sort of three-dimensional plate which travels with the fibrous assembly, accompanying it during its formation and during compaction. It can also be called a “thin skin” because it takes up little space since it has a shape corresponding to the geometry of the desired preform. The application support may for example consist of a set of substantially flat sections (forming panels), the geometries of which may be similar or vary, located in one or more panels, optionally completed by curved panels and / or openings for receiving movable mold parts. The application support is also typically reusable, that is to say that it will be used in several cycles of manufacturing fiber preforms.
Selon des variantes, le support d'application est réalisé en matériau à base polymère, en particulier en matériau composite à base fibres/polymère. L'épaisseur du support d'application dépend de manière générale du choix du matériau composite qui le constitue, et est également fonction de l'application envisagée, elle-même conditionnant la masse, l'inertie thermique, la rigidité, le comportement en température, etc. L'homme du métier choisira donc un matériau approprié pour le support d'application, en fonction de l'utilisation envisagée. Le matériau du support d'application est préférablement choisi pour avoir une certaine rigidité qui permet de conserver sa forme. According to variants, the application support is made of a polymer-based material, in particular of a fiber / polymer-based composite material. The thickness of the application support generally depends on the choice of the composite material which constitutes it, and is also a function of the envisaged application, itself conditioning the mass, thermal inertia, rigidity, temperature behavior. , etc. Those skilled in the art will therefore choose an appropriate material for the application support, depending on the intended use. The material of the application support is preferably chosen to have a certain rigidity which allows its shape to be retained.
A titre d'exemple, pour une plage de mise en oeuvre des préformes entre 0 et 160°C, on privilégiera pour le support d'application un composite type carbone/époxy. Pour une plage supérieure en température, par ex. 160-240°C, on pourra employer pour le support d'application un composite carbone/BMI. By way of example, for a range of application of the preforms between 0 and 160 ° C., a carbon / epoxy type composite will be preferred for the application support. For a higher temperature range, eg. 160-240 ° C, a carbon / BMI composite can be used for the application support.
De manière générale, le support d'application peut avoir une épaisseur entre 1 et 5 mm. L'épaisseur du support d'application peut être constante sur toute son étendue, ou varier localement. In general, the application support can have a thickness between 1 and 5 mm. The thickness of the application support may be constant over its entire extent, or vary locally.
Le matériau constitutif du support d'application est avantageusement choisi pour être compatible avec une potentielle opération de préchauffage nécessaire à l'activation de certains binders, notamment pour assurer une maîtrise de la géométrie (dilatation thermique contrôlée) sur la plage de température 50 à 200°C. The material constituting the application support is advantageously chosen to be compatible with a potential preheating operation necessary for the activation of certain binders, in particular to ensure control of the geometry (controlled thermal expansion) over the temperature range 50 to 200 ° C.
Optionnellement, la phase de compactage inclut un chauffage des outils de compactage. Le support d'application peut-être avantageusement fonctionnalisé pour prendre en compte divers aspects du procédé de fabrication de la préforme, respectivement du composite. Selon les variantes, le support d'application est configuré pour permettre le maintien/le relâchement/le glissement d'une ou plusieurs structures textiles pendant les différentes phases du procédé. Optionally, the compaction phase includes heating the compaction tools. The application support can advantageously be functionalized to take into account various aspects of the process for manufacturing the preform, respectively the composite. According to the variants, the application support is configured to allow the maintenance / relaxation / sliding of one or more textile structures during the different phases of the process.
Le maintien des structures textiles est un aspect qui découle de la potentielle déformation ou mouvement des renforts textiles/fibreux durant les phases de transitiques. Le relâchement du textile doit intervenir avant l'étape de mise en forme pour pouvoir laisser le textile se déformer et s'avaler sans contraintes (hors géométriques). Ces deux opérations « maintien/relâchement » peuvent être assurées par des moyens de rétention intégrés au support d'application, que l'on peut nommer en anglais « line grippers ». Les moyens de rétention peuvent être conçus pour permettre leur actionnement durant les phases de transitique et être désactivés/ escamotés durant la phase de mise en forme. Par exemple, les moyens de rétention peuvent prendre la forme d'un ensemble d'aiguilles escamotables montées à un ou plusieurs endroits du support d'application. Les aiguilles sont maintenues en saillie ou rétractées par un mécanisme approprié. Dans la configuration active, ces aiguilles sont en saillie et permettent de retenir le dépôt fibreux. De préférence, les moyens de rétention sont configurés pour être désactivables par les outils du poste de compactage ou par les moyens de déplacement/préhension. The maintenance of textile structures is an aspect that results from the potential deformation or movement of the textile / fiber reinforcements during the transitic phases. The relaxation of the textile must take place before the shaping step in order to be able to allow the textile to deform and swallow without constraints (except geometric). These two “hold / release” operations can be performed by retention means integrated into the application support, which can be called “line grippers” in English. The retention means can be designed to allow their actuation during the transitic phases and be deactivated / retracted during the shaping phase. For example, the retention means can take the form of a set of retractable needles mounted at one or more locations on the application support. The needles are kept protruding or retracted by a suitable mechanism. In the active configuration, these needles protrude and allow the fibrous deposit to be retained. Preferably, the retention means are configured to be deactivatable by the tools of the compacting station or by the displacement / gripping means.
La face d'application du support d'application peut comprendre un traitement de surface anti-adhésif, notamment type métallisation ou téflonnage. La fourniture d'un revêtement anti-adhésif permet de traiter la thématique de glissement des structures textiles/fibreuses (qui va permettre leur avalement contrôlé, déformation lors de la mise en forme). The application face of the application support may comprise a non-stick surface treatment, in particular of the metallization or Teflon type. The provision of a non-stick coating makes it possible to deal with the theme of sliding of textile / fibrous structures (which will allow their controlled swallowing, deformation during shaping).
Lors de l'étape de mise en forme de la structure textile/fibreuse, des brochages (écartement de fibres pour permettre une absence de matière localement) peuvent être nécessaires. On prévoira donc avantageusement des moyens compatibles avec les différents mouvements des broches et leur cinématique. During the step of shaping the textile / fiber structure, pinouts (spacing of fibers to allow an absence of material locally) may be necessary. Means compatible with the different movements of the pins and their kinematics will therefore be advantageously provided.
Dans certaines variantes, le support d'application pourrait intégrer un moyen de chauffage, qui peut prendre la forme de lignes résistives chauffantes, alimentées par une source extérieure. Ce moyen de chauffage peut être utilisé pour l'activation thermique du liant, sur tout ou partie de la surface du support d'application. In certain variants, the application support could integrate a heating means, which can take the form of resistive heating lines, supplied by an outside source. This heating means can be used for thermal activation of the binder, on all or part of the surface of the application support.
Le support d'application peut comprendre toutes sortes d'inserts non-fibreux, liés aux fonctionnalités que l'on souhaite prévoir pour la préforme. Ces inserts peuvent être des éléments de fixation ou pour le passage de matière, par exemple piquets, cylindres ou broches. Les inserts peuvent aussi être des capteurs, par exemple capteur de sollicitations mécaniques ou puce RFID (à titre d'exemples, les dimensions peuvent de tels capteurs peuvent être 50*20mm2 ou 30*30 mm2 ou autres). The application support can comprise all kinds of non-fibrous inserts, linked to the functionalities that one wishes to provide for the preform. These inserts can be fixing elements or for the passage of material, for example stakes, cylinders or pins. The inserts can also be sensors, for example mechanical stress sensor or RFID chip (by way of example, the dimensions of such sensors can be 50 * 20mm 2 or 30 * 30mm 2 or others).
Par ailleurs, le support d'application est avantageusement conçu pour prendre en compte le besoin d'interfaçage avec l'outillage de mise en forme (poste de compactage). Effectivement, le support d'application ayant vocation à être utilisé en cycle de production, il va subir des cycles de chargement/déchargement entre les outils de compactage. Le support d'application comprendra donc avantageusement des moyens de référencement ou centrage (par exemple des orifices traversants, bossages ou autres) coopérant avec des moyens correspondants dans le poste de compactage. Cela permet de garantir une reproductibilité de positionnement au niveau des zones de contact identifiées pour son support. Furthermore, the application support is advantageously designed to take into account the need for interfacing with the forming tool (compacting station). Indeed, since the application support is intended to be used in the production cycle, it will undergo loading / unloading cycles between the compaction tools. The application support will therefore advantageously comprise referencing or centering means (for example through orifices, bosses or the like) cooperating with corresponding means in the compacting station. This makes it possible to guarantee positioning reproducibility at the level of the contact zones identified for its support.
Il est aussi souhaitable que l'interfaçage permette une reprise des efforts de compression exercés par le moule sur le support d'application. Ces derniers devront être homogénéisés sur l'ensemble de la surface du support d'application. En effet, le support d'application de par ses constituants aura typiquement un comportement élastique pour des faibles déformations. Pour garantir le respect des côtes 3D de la préforme, il est souhaitable de limiter ces effets élastiques. Cette homogénéisation peut être assurée par fonctionnalisation de l'outillage en utilisant par exemple des plages d'élastomères placées sur les parois des outils de compression, dont les caractéristiques, notamment de positionnement, dureté, ou autres, sont choisies pour homogénéiser les efforts de compression. It is also desirable for the interfacing to allow the compressive forces exerted by the mold to be taken up on the application support. The latter must be homogenized over the entire surface of the application support. Indeed, the application support by its constituents will typically have an elastic behavior for low deformations. To ensure that the 3D dimensions of the preform are respected, it is desirable to limit these elastic effects. This homogenization can be ensured by functionalization of the tool by using, for example, areas of elastomers placed on the walls of the compression tools, the characteristics of which, in particular of positioning, hardness, or others, are chosen to homogenize the compressive forces. .
Outre l'interfaçage avec le poste de compactage, les moyens de référencement ou centrage du support d'application peuvent être mis à profit pour l'interfaçage avec les autres postes, notamment les postes d'application de matériaux fibreux. On pourra également prévoir d'autres moyens de référencement / centrage dans le support d'application. In addition to interfacing with the compaction station, the means for referencing or centering the application support can be used for interfacing with the other stations, in particular stations for applying fibrous materials. Other referencing / centering means could also be provided in the application support.
Dans certaines variantes, le support d'application peut être conçu de façon à être la surface moulante inférieure de la préforme. Ainsi, la surface d'application du support d'application est structurée pour correspondre partiellement ou entièrement à la forme désirée de la préforme. Avantageusement, l'état de surface du support d'application est réalisé pour permettre un « démoulage » aisé de la préforme. In some variations, the application support can be designed to be the lower molding surface of the preform. Thus, the application surface of the application support is structured to correspond partially or entirely to the desired shape of the preform. Advantageously, the surface condition of the application support is produced to allow easy “release” of the preform.
Dans le présent texte, on entend par « matériau fibreux » toutes sortes de matériaux composés de fibres ou filaments, individuels ou sous forme de mèches ou de nappes, structurés (tissés, tressés, NCF) ou non, englobant également toutes sortes de textiles. Les matériaux fibreux utilisés dans le cadre de l'invention sont appropriés pour former, dans la forme dans laquelle ils sont appliqués ou suite à leur assemblage sur le support d'application, un renfort fibreux pour une pièce composite. En général, le matériau fibreux est un matériau fibreux brut, contenant éventuellement un liant. Dans certaines variantes, le matériau fibreux comprend des sous-préformes, c'est-à-dire des structures fibreuses/textiles déjà compactées et/ou en forme. Le support d'application permet donc le dépôt et l'assemblage, de manière complémentaires et/ou empilée, de toutes sortes de fibres et textiles, ainsi que de préformes existantes, et leur combinaison. In the present text, the term “fibrous material” is understood to mean all kinds of materials composed of fibers or filaments, individual or in the form of rovings or sheets, structured (woven, braided, NCF) or not, also including all kinds of textiles. The fibrous materials used in the context of the invention are suitable for forming, in the form in which they are applied or following their assembly on the application support, a fibrous reinforcement for a composite part. In general, the fibrous material is a raw fibrous material, optionally containing a binder. In some variants, the fibrous material comprises sub-preforms, that is to say fibrous / textile structures already compacted and / or shaped. The application support therefore allows the deposition and assembly, in a complementary and / or stacked manner, of all kinds of fibers and textiles, as well as existing preforms, and their combination.
Le poste de compactage peut être de tout type approprié pour conférer sa forme ou géométrie finale à la préforme. A l'issue du compactage, le dépôt ou assemblage fibreux est cohérent et auto-portant. Le poste de compactage est généralement conçu comme une presse permettant le compactage, l'emboutissage ou l'estampage. Le poste de compactage comprend en général deux outils (ou moules) se faisant face, déplaçables l'un vers l'autre, et ayant des surfaces moulantes aux formes complémentaires, configurées selon la forme de la préforme désirée. La configuration des outils est souvent tridimensionnelle, mais il est possible de faire des préformes planes. On notera aussi que chaque outil (chaque côté de moule) peut comporter des sous-parties de moules mobiles indépendantes, selon la complexité des formes 3D à réaliser. Le support d'application constitue un moyen de support d'assemblages fibreux/textiles dont la manipulation et l'usage sont simples, et qui permet un compactage à pression ambiante, sans usage de vide comme par exemple dans la solution du US 2014/0175709. Le ou les postes d'application de fibres sont des stations de travail où l'on va déposer sur la surface d'application du support d'application des matières fibreuses. La matière est déposée selon toute technique appropriée, à la main par un opérateur ou de préférence de manière automatisée, par exemple par des têtes d'application. Le présent procédé est applicable avec des postes d'application opérant selon les techniques connues. En pratique, les matériaux fibreux sont déposés directement contre la surface d'application mais pour des passes ultérieures on peut déposer des matériaux fibreux sur un dépôt préalable, formant donc un assemblage de matériaux fibreux. The compacting station can be of any type suitable for imparting its final shape or geometry to the preform. At the end of the compacting, the deposit or fibrous assembly is coherent and self-supporting. The compaction station is generally designed as a press for compaction, stamping or stamping. The compaction station generally comprises two tools (or molds) facing each other, movable towards one another, and having molding surfaces with complementary shapes, configured according to the shape of the desired preform. The configuration of the tools is often three-dimensional, but it is possible to make flat preforms. It will also be noted that each tool (each side of the mold) may include independent mobile mold sub-parts, depending on the complexity of the 3D shapes to be achieve. The application support constitutes a means of support of fibrous / textile assemblies whose handling and use are simple, and which allows compaction at ambient pressure, without the use of vacuum, for example in the solution of US 2014/0175709 . The fiber application station (s) are work stations where fibrous materials are deposited on the application surface of the application support. The material is deposited by any suitable technique, by hand by an operator or preferably in an automated manner, for example by application heads. The present method is applicable with application stations operating according to known techniques. In practice, the fibrous materials are deposited directly against the application surface but for subsequent passes, fibrous materials can be deposited on a prior deposit, thus forming an assembly of fibrous materials.
Les postes d'application peuvent être du type : poste de projection de fibres, poste de placement de fibres ou poste de dépose de semi-produits textiles. The application stations may be of the type: fiber projection station, fiber placement station or station for depositing textile semi-products.
Pour l'hybridation de renforts, on déposera typiquement des matériaux fibreux selon au moins deux technologies différentes, et donc au niveau d'au moins deux postes d'application de fibres distincts et séparés. For the hybridization of reinforcements, fiber materials will typically be deposited according to at least two different technologies, and therefore at the level of at least two distinct and separate fiber application stations.
Conventionnellement, la matière fibreuse déposée peut contenir un liant (binder) et/ou un liant peut être ajouté, i.e. déposé sur la surface d'application et/ou sur les matériaux fibreux, au niveau des postes d'application ou d'un poste de dépôt de liant. Un tel liant peut être activable (polymérisation) thermiquement ou par photopolymérisation. Conventionally, the deposited fibrous material may contain a binder and / or a binder may be added, ie deposited on the application surface and / or on the fibrous materials, at the application stations or at a station. binder deposit. Such a binder can be activated (polymerization) thermally or by photopolymerization.
Le procédé peut comprendre une étape de détourage au niveau d'un poste de détourage, afin d'enlever l'excédent de matière de la préforme, et donc de la rendre « net-shape ». Le support d'application peut également être utilisé pour supporter la préforme pendant le détourage. Alternativement le détourage peut être opéré après séparation de la préforme de son support d'application. La présente invention a été développée dans le cadre du procédé de préformage textile. Toutefois, l'invention peut être appliquée et/ou transposée à d'autres procédé de production de composites et est généralisable à tous types de structures fibreuses/textiles sèches avec ou sans binders réactifs, quels que soient les procédés d'applications. The method may include a trimming step at a trimming station, in order to remove the excess material from the preform, and therefore to make it "net-shape". The application support can also be used to support the preform during trimming. Alternatively, the trimming can be performed after separation of the preform from its application support. The present invention has been developed in the context of the textile preforming process. However, the invention can be applied and / or transposed to other processes for the production of composites and can be generalized to all types of dry fiber / textile structures with or without reactive binders, whatever the application processes.
L'invention concerne également un procédé de fabrication d'une pièce composite comprenant les étapes suivantes : The invention also relates to a method of manufacturing a composite part comprising the following steps:
- fabrication d'une préforme fibreuse conformément au procédé décrit dans la présente demande ; - Manufacture of a fiber preform in accordance with the process described in the present application;
introduction de la préforme dans un moule et injection de résine pour imprégner la préforme, optionnellement complété par un chauffage du moule. introduction of the preform into a mold and injection of resin to impregnate the preform, optionally completed by heating the mold.
Selon un autre aspect, l'invention concerne un système de fabrication d'une pièce composite adapté pour la mise en oeuvre du présent procédé, comprenant : au moins un poste d'application de matériau fibreux ; un support d'application définissant une surface d'application ; un poste de préchauffage optionnel ; un poste de compactage configuré pour compacter le matériaux fibreux reposant sur le support d'application (12) entre deux outils ayant des faces de moulage complémentaires ; et des moyens pour déplacer le support d'application entre les différents postes. According to another aspect, the invention relates to a system for manufacturing a composite part suitable for implementing the present method, comprising: at least one station for applying fibrous material; an application support defining an application surface; an optional preheating station; a compacting station configured to compact the fibrous material resting on the application support (12) between two tools having complementary molding faces; and means for moving the application support between the different stations.
Selon les variantes, le système comprend une ou plusieurs des caractéristiques suivantes : Depending on the variant, the system includes one or more of the following features:
- un poste d'injection comportant deux outils configurés pour définir une cavité de moulage pour accueillir la préforme reposant sur le support d'application et des moyens pour introduire un matériau polymère liquide dans la cavité de moulage ; an injection station comprising two tools configured to define a molding cavity for receiving the preform resting on the application support and means for introducing a liquid polymer material into the molding cavity;
- le support d'application comprend des moyens de rétention des dépôts fibreux ; - le support d'application comprend des moyens de centrage aptes à coopérer avec des moyens correspondants prévus dans les postes d'application ou dans le poste de compactage ou au niveau des moyens de préhension/déplacement du support d'application . Description détaillée à l'aide des figures - the application support comprises means for retaining fibrous deposits; the application support comprises centering means able to cooperate with corresponding means provided in the application stations or in the compacting station or at the level of the gripping / displacement means of the application support. Detailed description using figures
D'autres particularités et caractéristiques de l'invention ressortiront de la description détaillée d'au moins un mode de réalisation avantageux présenté ci-dessous, à titre d'illustration, en se référant aux dessins annexés. Ceux-ci montrent : Other features and characteristics of the invention will emerge from the detailed description of at least one advantageous embodiment presented below, by way of illustration, with reference to the appended drawings. These show:
[Fig. 1] : une vue de principe du système de fabrication de préformes fibreuses, selon un mode de réalisation de l'invention ; [Fig. 1]: a principle view of the system for manufacturing fiber preforms, according to one embodiment of the invention;
[Fig. 2] : un diagramme illustrant les étapes du présent procédé, avec un système du type de la Fig.l ; [Fig. 2]: a diagram illustrating the steps of the present method, with a system of the type of FIG. 1;
[Fig. B] : un vue de principe, en perspective, d'un mode de réalisation de support d'application. La présente invention sera maintenant décrite dans le contexte d'une application au procédé hybride de préformage textile. La figure 1 représente une vue de principe du système de fabrication 10 de préformes fibreuses selon l'invention. Le système comprend : un support d'application 12 avec une face d'application 12.1 ; [Fig. B]: a principle view, in perspective, of an application support embodiment. The present invention will now be described in the context of an application to the hybrid textile preforming process. FIG. 1 represents a principle view of the system 10 for manufacturing fiber preforms according to the invention. The system comprises: an application support 12 with an application face 12.1;
- un premier poste d'application de matière fibreuse 14, par ex. du type « pick and place » ; - a first fibrous material application station 14, eg. of the “pick and place” type;
un second poste d'application de matière fibreuse 16, par ex. du type à projection de fibres ; a second fibrous material application station 16, e.g. of the fiber projection type;
un poste de préchauffage 18 a preheating station 18
- un poste de compactage 20 - a compaction station 20
un poste de détourage 22. a trimming station 22.
Ce système est remarquable en ce qu'il utilise un support d'application 12 mobile et réutilisable, pour la dépose de matériaux fibreux et leur support ainsi qu'un robot manipulateur 24 apte à se déplacer dans le système de sorte à déplacer/manipuler le support d'application 12 entre les différents postes. Le robot 22 n'est qu'un exemple. On peut employer toute sorte de moyen de préhension et déplacement du support d'application 12 permettant le déplacement du support d'application 12 et l'installation de ce dernier dans les différents postes. On peut également avoir une combinaison de robots manipulateurs, éventuellement avec des convoyeurs. This system is remarkable in that it uses a mobile and reusable application support 12, for the deposit of fibrous materials and their support as well as a robot. manipulator 24 able to move in the system so as to move / manipulate the application support 12 between the different stations. Robot 22 is just one example. Any kind of gripping and displacement means can be used for the application support 12 allowing the displacement of the application support 12 and the installation of the latter in the various stations. It is also possible to have a combination of manipulating robots, possibly with conveyors.
Les postes 14 à 22 (ou stations) sont, pour leur principe de fonctionnement, connus en tant que tels et ne font pas l'objet de l'invention ; ils ne seront donc pas décrits en détail. Le signe de référence 26 désigne un poste d'injection qui permet l'imprégnation de la résine, par injection, conformément à un procédé RTM. Un tel poste d'injection comprend deux outils de moulage rigides qui définissent entre eux une cavité (ou un entrefer) configurée pour recevoir la préforme. Le système 10, associé au poste d'injection 26, forme un système de production de pièces composites. Le support d'application 12 peut être fonctionnalisé afin de pourvoir à différentes problématiques de son utilisation. Le support d'application peut notamment comprendre une ou plusieurs des caractéristiques suivantes : des moyens de référencement, pouvant prendre la forme d'ouvertures traversantes, de bossages, ou autres, permettant de faciliter la manipulation et/ou le référencement du support d'application, c'est-à-dire le positionnement relatif du support d'application avec les outils des différents postes, et/ou sa manipulation/préhension par le robot ou autre moyen de manipulation/déplacement du support d'application The stations 14 to 22 (or stations) are, for their operating principle, known as such and are not the subject of the invention; they will therefore not be described in detail. The reference sign 26 designates an injection station which allows the resin to be impregnated, by injection, in accordance with an RTM process. Such an injection station comprises two rigid molding tools which define between them a cavity (or an air gap) configured to receive the preform. The system 10, associated with the injection station 26, forms a system for the production of composite parts. The application support 12 can be functionalized in order to provide for various problems of its use. The application support can in particular comprise one or more of the following characteristics: referencing means, which can take the form of through openings, bosses, or the like, making it possible to facilitate the handling and / or referencing of the application support , that is to say the relative positioning of the application support with the tools of the different stations, and / or its handling / gripping by the robot or other means of handling / displacement of the application support
un revêtement antiadhésif, par ex. métallisation, téflonnage ou équivalent, pour faciliter le glissement des plis fibreux, a non-stick coating, eg. metallization, teflon or equivalent, to facilitate the sliding of the fibrous folds,
des moyens de rétention des dépôts fibreux configurés pour retenir les dépôts fibreux sur la surface d'application, en particulier lors du transport du support d'application entre les différents postes. Les moyens de rétention sont de préférence actionnables de manière sélective. En particulier, les moyens de rétention des dépôts fibreux sont préférablement conçus pour être désactivables, de manière manuelle ou automatique, lors de l'installation du support d'application dans l'outil inférieur du poste de compactage. Les moyens de rétention peuvent comprendre un ou plusieurs ensembles d'aiguilles répartis dans une ou plusieurs régions du support d'application. Les aiguilles sont montées de manière escamotable sur le support d'application, de sorte à être par défaut en saillie sur la surface d'application, et automatiquement escamotées lors de la fermeture des outils du poste de compactage. means for retaining the fibrous deposits configured to retain the fibrous deposits on the application surface, in particular during the transport of the application support between the different stations. The retention means are preferably selectively operable. In particular, the means of retention of fibrous deposits are preferably designed to be deactivatable, manually or automatically, during installation of the application support in the lower tool of the compaction station. The retention means may comprise one or more sets of needles distributed in one or more regions of the application support. The needles are mounted in a retractable manner on the application support, so as to be by default projecting on the application surface, and automatically retracted when the tools of the compacting station are closed.
La Fig. B représente une vue de principe d'une variante de préforme 12. La préforme est une pièce rectangulaire tridimensionnelle. La face supérieure 12.1 est une face d'application pour les matériaux fibreux. Dans l'exemple, la préforme est conformée en trois pans distribués dans la longueur. Le signe de référence 12.3 désigne une ouverture dans les deux premiers pans (en partant de la gauche) pour le passage d'un outil de moulage (voir plus bas). Le signe de référence 12.4 désigne deux séries d'aiguilles d'accrochage escamotables formant les lignes grippers. Par ailleurs, deux trous de centrage 12.5 sont prévus pour l'interfaçage avec l'outil inférieur du poste de compactage. Enfin, la ligne pointillée 12.6 symbolise des lignes résistives chauffantes incorporées dans le corps du support d'application 12. Fig. B shows a principle view of a variant of the preform 12. The preform is a three-dimensional rectangular part. The upper face 12.1 is an application face for fibrous materials. In the example, the preform is shaped in three sections distributed in the length. Reference sign 12.3 designates an opening in the first two sections (starting from the left) for the passage of a molding tool (see below). The reference sign 12.4 designates two series of retractable hooking needles forming the gripper lines. Furthermore, two centering holes 12.5 are provided for interfacing with the lower tool of the compaction station. Finally, the dotted line 12.6 symbolizes resistive heating lines incorporated in the body of the application support 12.
Les 3 pans du support d'application 12 sont sensiblement plats, avec une faible épaisseur, typiquement entre 1 et 5 mm. Le support d'application peut être fabriqués à partir de plis de prépreg carbone (environ 1600 à 2000 g/m2). La tenue est bonne pour une température de service jusqu'à 180°C. The 3 sides of the application support 12 are substantially flat, with a small thickness, typically between 1 and 5 mm. The application medium can be made from plies of carbon prepreg (approximately 1600 to 2000 g / m 2 ). The resistance is good for a service temperature up to 180 ° C.
On décrira maintenant en référence à la Figure 2 les différentes phases du présent procédé, tel qu'il peut être mis en œuvre dans un système 10 du type de la Figure 1. Fig.2 a). On reconnaît le support d'application 12 utilisé dans le procédé, dont la face supérieure dite surface d'application 12.1 est destinée à recevoir les matériaux fibreux au niveau d'un ou plusieurs postes d'application de fibres. Le support d'application 12 est avantageusement fonctionnalisé comme en Fig.3. Les matériaux fibreux sont déposés sur le support d'application 12 au cours de la phase d'application (Fig. 2b). On dépose une ou plusieurs couches de matériaux fibreux sur la face d'application 12.1, et cela au niveau d'un ou plusieurs postes d'application de fibres. Le support d'application est positionné dans un premier poste d'application pour le dépôt de matière fibreuse selon une première technologie, par exemple projection de fibres 16. On peut former une ou plusieurs couches de fibres 42. Après ce dépôt de matière fibreuse, le support d'application peut être déplacé vers la phase suivante. Toutefois, l'intérêt particulier du support d'application 12 est de permettre de combiner les technologies de dépôt de matériau fibreux. Toujours dans la phase d'application, le support d'application peut donc avantageusement être déplacé/ positionné et installé dans un autre poste d'application, par exemple du type « pick and place ». Dans ce poste, on dépose alors des plis de nappes textiles, sur le ou les couches de matière fibreuse déposées au premier poste d'application. With reference to FIG. 2, the various phases of the present method will now be described, as it can be implemented in a system 10 of the type of FIG. 1. FIG. 2 a). The application support 12 used in the process can be recognized, the upper face of which, called the application surface 12.1, is intended to receive the fibrous materials at one or more fiber application stations. The application support 12 is advantageously functionalized as in Fig.3. The fibrous materials are deposited on the application support 12 during the application phase (Fig. 2b). One or more layers of fibrous materials are deposited on the application face 12.1, and this at one or more fiber application stations. The application support is positioned in a first application station for the deposition of fibrous material according to a first technology, for example projection of fibers 16. One or more layers of fibers 42 can be formed. After this deposition of fibrous material, application support can be moved to the next phase. However, the particular advantage of the application support 12 is that it makes it possible to combine the technologies for depositing fibrous material. Still in the application phase, the application support can therefore advantageously be moved / positioned and installed in another application station, for example of the “pick and place” type. In this station, folds of textile webs are then deposited on the layer or layers of fibrous material deposited at the first application station.
Conventionnellement, la matière fibreuse déposée peut contenir un liant (binder) et/ou un liant peut être ajouté, i.e. déposé sur la surface d'application et/ou sur les matériaux fibreux, au niveau des postes d'application ou d'un poste de dépôt de liant. Conventionally, the deposited fibrous material may contain a binder and / or a binder may be added, ie deposited on the application surface and / or on the fibrous materials, at the application stations or at a station. binder deposit.
Le support d'application, qui voyage avec les dépôts de matières fibreuses réalisés sur sa face d'application 12.1, va ainsi permettre de facilement combiner les technologies d'application, pour obtenir une préforme « hybride ». Le ou les dépôts de matière fibreuse 17 réalisés au niveau d'un ou plusieurs postes d'applications sont appelés dépôts, ensembles ou assemblages fibreux. The application support, which travels with the deposits of fibrous materials produced on its application face 12.1, will thus make it possible to easily combine the application technologies, to obtain a “hybrid” preform. The deposit (s) of fibrous material 17 produced at one or more application stations are called deposits, sets or fibrous assemblies.
Lors du dépôt de matière fibreuse, les aiguilles de rétention 12.4 sont préférablement actives. When depositing fibrous material, the retention needles 12.4 are preferably active.
La phase suivante, optionnelle, est la phase de préchauffage. L'assemblage fibreux 17 de la phase d'application, supporté par le support d'application 12, est soumis à un traitement thermique (Fig.2c). Typiquement le support d'application 12 avec l'assemblage fibreux 44 (résultant de l'application de fibres selon une ou plusieurs technologies) est placé dans un four 18 statique ou à tunnel (convoyeur) pour chauffer l'assemblage fibreux et ramollir le liant et/ou entamer le processus de polymérisation. Après le passage dans le four, le support d'application 12 est positionné au niveau du poste de compactage 20, pour opérer la phase de compactage. Celui-ci comprend une presse avec deux outils 20.1 disposés face à face, typiquement l'un au-dessus de l'autre. Les deux outils sont rigides et ont des faces de moulage en regard, complémentaires l'une de l'autre. Chaque outil 20.1 peut être constitué de plusieurs parties de moule, déplaçables indépendamment. Dans l'exemple représenté, le trait pointillé au niveau de l'outil 20.1 supérieure représente une cavité centrale 20.2 qui reçoit une partie du moule, dite « punch » qui se projette hors de l'outil 20.1 inférieur, et passe à travers une ouverture dans le support d'application, telle que l'ouverture 12. B. The next optional phase is the preheating phase. The fibrous assembly 17 of the application phase, supported by the application support 12, is subjected to a heat treatment (Fig.2c). Typically the application support 12 with the fibrous assembly 44 (resulting from the application of fibers according to one or more technologies) is placed in a static or tunnel oven 18 (conveyor) to heat the fibrous assembly and soften the binder. and / or start the polymerization process. After passing through the oven, the application support 12 is positioned at the level of the compaction station 20, in order to operate the compaction phase. This comprises a press with two tools 20.1 arranged face to face, typically one above the other. The two tools are rigid and have facing molding faces, complementary to each other. Each tool 20.1 can be made up of several mold parts which can be moved independently. In the example shown, the dotted line at the level of the upper tool 20.1 represents a central cavity 20.2 which receives a part of the mold, called a “punch” which projects out of the lower tool 20.1, and passes through an opening in the application support, such as opening 12. B.
Le compactage commence par le positionnement (installation) du support d'application avec le dépôt fibreux sur la face de moulage inférieure (dl), puis l'outil 20.1 supérieur est abaissé (d2). L'une des séries d'aguilles de rétention 12.4 est préférablement désactivée avant la fermeture pour permettre un certain glissement du matériau fibreux. The compaction begins with the positioning (installation) of the application support with the fibrous deposit on the lower molding face (dl), then the upper tool 20.1 is lowered (d2). One of the sets of retention pins 12.4 is preferably deactivated prior to closing to allow some sliding of the fibrous material.
Lorsque la presse 20 est fermée, les deux outils 20.1 sont configurés pour se rapprocher de manière complémentaire, dans une configuration correspondant à la forme désirée pour la préforme. Le compactage est contrôlé pour obtenir la densité de fibres désirée. C'est la configuration de la Fig.2 d3). C'est dans cette configuration fermée que le punch est déployé à travers l'ouverture 12.3. When the press 20 is closed, the two tools 20.1 are configured to approach each other in a complementary manner, in a configuration corresponding to the shape desired for the preform. Compaction is controlled to achieve the desired fiber density. This is the configuration of Fig. 2 d3). It is in this closed configuration that the punch is deployed through the opening 12.3.
La presse est ensuite ouverte (les outils sont écartés, cf. Fig. 2 d4) et la préforme ainsi obtenue, indiquée 46 par contraste avec l'assemblage fibreux 44, peut être extraite. La préforme 46 et le support d'application 12 peuvent être extraits séparément. Mais, le support d'application 12 est particulièrement intéressant car il permet une extraction facile de la préforme 46. Au lieu de manipuler directement la préforme, il est plus aisé de saisir le support d'application 12, qui supporte la préforme 46. The press is then opened (the tools are removed, cf. Fig. 2 d4) and the preform thus obtained, indicated 46 in contrast to the fibrous assembly 44, can be extracted. The preform 46 and the application support 12 can be extracted separately. However, the application support 12 is particularly interesting because it allows easy extraction of the preform 46. Instead of directly handling the preform, it is easier to grip the application support 12, which supports the preform 46.
Pour l'obtention d'un composite, la préforme 46 est placés dans un moule d'injection 26 qui comprend deux parties de moule 26.1 de forme complémentaires et définissant une cavité de moulage 26.2 dans laquelle on place la préforme 46. La préforme 46 peut être installée seule dans le moule d'injection 26 mais est dans la figure 2 e) supportée par le support d'application 12. Une résine, contenue dans un réservoir chauffant 26.4, est introduite, via un canal 26. B, dans la cavité de moulage 26.2. Le moule 26 est chauffé à la température requise pour la polymérisation. Le moule est ensuite ouvert et le composite extrait. La présence du support d'application 12 facilite le démoulage. To obtain a composite, the preform 46 is placed in an injection mold 26 which comprises two mold parts 26.1 of complementary shape and defining a mold cavity 26.2 in which the preform 46 is placed. The preform 46 can be installed alone in the injection mold 26 but is in Figure 2 e) supported by the application support 12. A resin, contained in a heating tank 26.4, is introduced, via a channel 26. B, in the mold cavity 26.2. The mold 26 is heated to the temperature required for the polymerization. The mold is then opened and the composite extracted. The presence of the application support 12 facilitates demolding.

Claims

REVENDICATIONS
1. Procédé de fabrication d'une préforme fibreuse pour un composite comprenant : fourniture d'un support d'application (12), mobile, définissant une surface d'application (12.1) ; une phase d'application de matériaux fibreux comprenant : positionnement du support d'application (12) au niveau d'au moins un poste d'application de matériau fibreux (14, 16), et application d'au moins un matériau fibreux sur la surface d'application (12.1) du support d'application (12) ; une phase de compactage comprenant : positionnement du support d'application au niveau d'un poste de compactage (20) de la structure fibreuse, compression du dépôt fibreux (44) dans le poste de compactage (20), le support d'application (12) étant placé entre les outils de compactage (20.1) et supportant le dépôt fibreux pendant le compactage, extraction du support d'application (12) et de la préforme fibreuse (46) obtenue. A method of manufacturing a fiber preform for a composite comprising: providing an application support (12), movable, defining an application surface (12.1); a phase of applying fibrous materials comprising: positioning the application support (12) at at least one fibrous material application station (14, 16), and applying at least one fibrous material to the application surface (12.1) of the application support (12); a compacting phase comprising: positioning of the application support at the level of a compacting station (20) of the fibrous structure, compression of the fibrous deposit (44) in the compacting station (20), the application support ( 12) being placed between the compaction tools (20.1) and supporting the fibrous deposit during compaction, extraction of the application support (12) and of the fibrous preform (46) obtained.
2. Procédé de fabrication selon la revendication 1, comprenant une phase de préchauffage précédant la phase de compactage, dans laquelle le support d'application avec le(s) dépôt(s) fibreux est soumis à un traitement thermique.2. The manufacturing method according to claim 1, comprising a preheating phase preceding the compacting phase, in which the application support with the fibrous deposit (s) is subjected to a heat treatment.
B. Procédé de fabrication selon la revendication 1 ou 2, dans lequel la phase de compactage inclut un chauffage des outils de compactage. B. The manufacturing method according to claim 1 or 2, wherein the compacting phase includes heating the compacting tools.
4. Procédé de fabrication selon l'une quelconque des revendications précédentes, dans lequel lors de la phase d'application on dépose sur le support d'application un ou plusieurs matériaux fibreux en positionnant le support d'application à au moins un poste d'application de matériaux fibreux choisi parmi : un poste de projection de fibres (16), un poste de placement de fibres, et un poste de dépose de tissus (14). 4. The manufacturing method according to any one of the preceding claims, wherein during the application phase is deposited on the application support one or more fibrous materials by positioning the application support at at least one station. application of fibrous materials selected from: a fiber projection station (16), a fiber placement station, and a fabric placement station (14).
5. Procédé de fabrication selon la revendication 4, dans lequel lors de la phase d'application on dépose sur le support d'application un ou plusieurs matériaux fibreux à au moins deux desdits postes d'application de matériaux fibreux. 5. The manufacturing method according to claim 4, wherein during the application phase is deposited on the application support one or more fibrous materials at at least two of said application stations of fibrous materials.
6. Procédé de fabrication selon l'une quelconque des revendications précédentes, dans lequel le support d'application comprend des moyens (12.4) de rétention des dépôts fibreux. 6. The manufacturing method according to any one of the preceding claims, wherein the application support comprises means (12.4) for retaining fibrous deposits.
7. Procédé de fabrication selon l'une quelconque des revendications précédentes, dans lequel le support d'application comprend des moyens de centrage (12.5) aptes à coopérer avec des moyens correspondants prévus dans les postes d'application (14, 16) ou dans le poste de compactage ou au niveau des moyens de préhension/déplacement (24) du support d'application. 7. The manufacturing method according to any one of the preceding claims, wherein the application support comprises centering means (12.5) adapted to cooperate with corresponding means provided in the application stations (14, 16) or in the compacting station or at the level of the gripping / displacement means (24) of the application support.
8. Procédé de fabrication selon l'une quelconque des revendications précédentes, dans lequel après la phase de compactage, le support d'application avec la préforme est positionné dans un poste de détourage (22), la préforme étant séparée du support d'application à l'issue du détourage. 8. The manufacturing method according to any one of the preceding claims, wherein after the compacting phase, the application support with the preform is positioned in a trimming station (22), the preform being separated from the application support. after clipping.
9. Procédé de fabrication d'une pièce composite comprenant les étapes suivantes : fabrication d'une préforme fibreuse conformément au procédé selon l'une quelconque des revendications 1 à 8 ; introduction de la préforme (46) dans un moule (26) et injection de résine pour imprégner la préforme, optionnellement complété par un chauffage du moule. 9. A method of manufacturing a composite part comprising the following steps: manufacturing a fiber preform according to the method according to any one of claims 1 to 8; introduction of the preform (46) into a mold (26) and injection of resin to impregnate the preform, optionally completed by heating the mold.
10. Système de fabrication d'une pièce composite adapté pour la mise en oeuvre du procédé selon l'une quelconque des revendications 1 à 8, comprenant : au moins un poste d'application de matériau fibreux (14, 16) ; un support d'application (12) définissant une surface d'application (12.1) ; un poste de préchauffage (18) optionnel ; un poste de compactage (20) configuré pour compacter le matériaux fibreux reposant sur le support d'application (12) entre deux outils (20.1) ayant des faces de moulage complémentaires ; des moyens (24) pour déplacer le support d'application(12) entre les différents postes. 10. A system for manufacturing a composite part suitable for implementing the method according to any one of claims 1 to 8, comprising: at least one station for applying fibrous material (14, 16); an application support (12) defining an application surface (12.1); an optional preheating station (18); a compacting station (20) configured to compact the fibrous material resting on the application support (12) between two tools (20.1) having complementary molding faces; means (24) for moving the application support (12) between the different stations.
11. Système de fabrication d'une pièce composite selon la revendication 10, comprenant en outre un poste d'injection (26) comprenant deux outils configurés pour définir une cavité de moulage (26.2) pour accueillir la préforme (46) reposant sur le support d'application (12) et des moyens (26. S, 26.4) pour introduire un matériau polymère liquide dans la cavité (26.2). 11. A system for manufacturing a composite part according to claim 10, further comprising an injection station (26) comprising two tools configured to define a mold cavity (26.2) for receiving the preform (46) resting on the support. application (12) and means (26. S, 26.4) for introducing a liquid polymer material into the cavity (26.2).
12. Système de fabrication d'une pièce composite selon la revendication 10 ou 11, dans lequel le support d'application comprend des moyens de rétention des dépôts fibreux et/ou des moyens de centrage (12.5) aptes à coopérer avec des moyens correspondants prévus dans les postes d'application ou dans le poste de compactage ou au niveau des moyens de préhension/déplacement du support d'application. 12. A system for manufacturing a composite part according to claim 10 or 11, wherein the application support comprises means for retaining fibrous deposits and / or centering means (12.5) able to cooperate with corresponding means provided. in the application stations or in the compaction station or at the level of the gripping / displacement means of the application support.
PCT/EP2020/070386 2019-07-19 2020-07-17 Method for manufacturing preforms for composite materials WO2021013769A1 (en)

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FR1908224A FR3098749B1 (en) 2019-07-19 2019-07-19 Process for manufacturing preforms for composite materials

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4432716A (en) * 1981-03-20 1984-02-21 Lignotock Verfahrenstechnik Gmbh Apparatus for moulding three-dimensionally shaped moulded articles from binder-containing web-like non-woven fabrics
EP1250991A1 (en) 2000-12-29 2002-10-23 Ford Global Technologies, Inc. A processing system for the automated manufacture of preforms
US20140175709A1 (en) 2012-12-20 2014-06-26 Cytec Industries Inc. Method for forming shaped preform
DE102013009046A1 (en) * 2013-05-28 2014-12-04 Daimler Ag Method for forming a two-dimensional fiber semi-finished product and device
FR3008642A1 (en) 2013-07-22 2015-01-23 Safran INJECTION MOLDING PROCESS OF A COMPOSITE MATERIAL PART WITH PRIOR PRE-CONSOLIDATION OF THE FIBROUS PREFORM
WO2020002408A1 (en) 2018-06-26 2020-01-02 Schmidt & Heinzmann Gmbh & Co. Kg Preform tool at least for producing a preform of a composite component

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4432716A (en) * 1981-03-20 1984-02-21 Lignotock Verfahrenstechnik Gmbh Apparatus for moulding three-dimensionally shaped moulded articles from binder-containing web-like non-woven fabrics
EP1250991A1 (en) 2000-12-29 2002-10-23 Ford Global Technologies, Inc. A processing system for the automated manufacture of preforms
US20140175709A1 (en) 2012-12-20 2014-06-26 Cytec Industries Inc. Method for forming shaped preform
DE102013009046A1 (en) * 2013-05-28 2014-12-04 Daimler Ag Method for forming a two-dimensional fiber semi-finished product and device
FR3008642A1 (en) 2013-07-22 2015-01-23 Safran INJECTION MOLDING PROCESS OF A COMPOSITE MATERIAL PART WITH PRIOR PRE-CONSOLIDATION OF THE FIBROUS PREFORM
WO2020002408A1 (en) 2018-06-26 2020-01-02 Schmidt & Heinzmann Gmbh & Co. Kg Preform tool at least for producing a preform of a composite component

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FR3098749B1 (en) 2023-01-20

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