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
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2101/00—Use of unspecified macromolecular compounds as moulding material
  • B29K2101/10—Thermosetting resins

Definitions

• the present invention relates to a method for producing a preform for a fiber composite component and to a method for producing a semi-finished textile product for a preform. Furthermore, the invention relates to a semi-finished textile product for producing a preform for a fiber composite component.
• preforms are made of binder-provided fiber layers (also called preform), which can also be provisionally brought into shape, and later in the context of processes such as RTM (resin transfer molding) method, RIM (resin injection molding) method or other vacuum and / or pressure-assisted injection process in a mold embedded in a matrix resin, which is then cured.
• RTM resin transfer molding
• RIM resin injection molding
• the preforms not only have the advantage of being flexible, but also shearable to a certain extent, so that they can also be incorporated into more complex molding tools.
• the binder has as an important function, the fibers of the preformed
• the binder is applied in powder form in a separate operation on the layers of reinforcing fibers, in which the binder powder is sintered or fused onto the fibers, so that it does not trickle out in subsequent transport or processing steps.
• this equipment makes the textile semi-finished products, to some extent, inherently rigid and lose their textile soft character. They are then only in the heated state, so hot transform, to make a preform.
• the binder fibers or filaments are thermoplastic based binders such as Polyesters, polyamides, polyethersulfones or mixtures thereof.
• thermoplastic based binders such as Polyesters, polyamides, polyethersulfones or mixtures thereof.
• a disadvantage is that such binder fibers or filaments have a high melting point and therefore must be heated to frequently over 200 ° C in order to ensure a sufficient dimensional stability of the preforms.
• these binder fibers or filaments are often poorly compatible with the matrix resin systems in the further processing of preforms into fiber composites.
• Fibrous layers and the nonwoven fabric layers are sewn together to the cohesion and thus the handling of the Fasergelegeantechnische
• the present invention is based on the object, the known
• the object is achieved by a method for producing a
• the object is achieved by a method for producing a semi-finished textile product for a preform with the steps:
• Long-chain reaction resins are here understood to mean solid resins without hardeners, ie unhardened thermosets, which therefore still have thermoplastic properties, but nevertheless have a certain brittleness in the cooled state.
• Webs are understood to mean a three-dimensional arrangement of fine endless thread or of a plurality of fine threads and / or thread fragments
• Fiber reinforcement layer so equipped with binder that it retains its textile deformation properties and draping a mold with the
• Fiber reinforcement layer in the cold state i. allowed without additional heating step before the deformation step. Because by the application by spraying it is possible that the binder before the impact on the fiber reinforcement layer already on the ambient air cools so far that it is at least partially solidified when hitting and forms a web.
• Fiber reinforcement layer in the desired form still needed a heat input.
• heating is sufficient which, by utilizing the thermoplastic properties of the long-chain reaction resins used as binders, leads to melting and thus adhesion of the binder to the fiber reinforcement layer.
• a complete melting of the binder is not required. This not only leads to a simplification, but overall to a significant
• the preparation of the binder as a web also has the advantage of a rapid, efficient and homogeneous impregnation of the preform with matrix resin in the
• the fiber reinforcement layers may be single, scrim layers, scrims, fabrics, knits, nonwovens, mats or braids, or combinations thereof.
• the layers forming a clutch are also called and form Ply in particular unidirectional, bi-directional, biaxial or multi-axial clutches.
• More complex layers may also be constructed of layers of unidirectional, bidirectional, biaxial and / or multiaxial layers, woven fabrics, nonwovens, mats, braids or combinations thereof.
• Fiber reinforcement layers may include, for example, synthetic fibers, glass fibers,
• Aramid fibers are particularly preferred synthetic fibers.
• Hybrid fibers are understood in particular to be fibers from combinations of the fiber materials mentioned.
• a further advantage is that the binder web is brittle and in the further processing or during handling and / or the transport before the further step of reshaping break off partially smaller fragments of the binder web and penetrate into the fiber reinforcing layer.
• the binder also spreads in the fiber reinforcement layer, allowing more efficient fixation of the
• Binders are selected which are compatible with the matrix resin, which are used in the further processing of different preforms to fiber composite components.
• the application of the binder in web form allows, in particular with the introduction of a binder nonwoven layer, to manage with significantly lower basis weights of the binder and still achieve a similar binding effect. This is especially true when using binder web based on long chain reaction resins that are solid at room temperature, and especially when using Duroplast based binder web.
• the binder web is sprayed with a basis weight in the range of 3 g / m 2 to 10 g / m 2 , preferably from 5 g / m 2 to 7 g / m 2 . It has proven to be advantageous when spraying the distance to
• Fiber reinforcement layer to be chosen such that the binder is not completely solidified when hitting the fiber reinforcement layer.
• an adhesive effect may occur which results in the binder web being fixed in position on the fiber reinforcement layer at least to a limited extent.
• This effect can be further increased by using binder based on long chain reaction resins which are solid at room temperature, especially thermoset-based, by taking advantage of the brittleness of the binder web and the frequent entanglement of fibrous fibers and fragments, which also causes slippage the web as a whole is reduced relative to the underlying fiber reinforcing layer.
• the special structure of a web which can be compared, for example, with the structure of cotton candy, the drapability and deformability of the fiber reinforcement layer provided with binder web are not appreciably affected even during cold forming.
• a binder with a melting point below 125 ° C, more preferably below 100 ° C is sprayed.
• a melting point below 125 ° C, more preferably below 100 ° C.
• Fiber composite component to be used Fiber composite component to be used.
• a low-melting binder is advantageous since energy can be saved in the production of the preform or in the equipment of fiber reinforcement layers, because low-melting binder need not be heated so much to be sprayed on.
• the web of binder is sprayed onto the underlying fiber reinforcing layer as a discontinuous pattern, such as a dot or line pattern.
• Fiber reinforcement layer is achieved without the binder web forms a coherent surface.
• spraying as a discontinuous pattern allows local variations in the amount of binder, which correspond to the required local binding effect for the respective preform, without major procedural effort can be adjusted. In this case, locally larger contiguous surfaces of the binder web can occur.
• Binder disposed above a second fiber reinforcement layer can also be equipped with a binder web.
• Fiber reinforcement layers are equipped with a binder web, are oriented advantageously on the mechanical requirements of the respective preform or on the resulting fiber composite component.
• the heating of the reformed fiber reinforcement layer (s) is performed by means of hot air and / or infrared radiation and / or microwave radiation.
• the heating of hot air is favored by the very permeable structure of a binder web and allows at relatively low process complexity, an efficient and rapid heating and fixing of the formed fiber reinforcement layer (s).
• Cooling of the preform by means of air, namely cold air, is preferably also carried out. Under certain circumstances, the same blower device can be used as when heating with hot air.
• these variants of the forming process allow to easily perform post-corrections, e.g. at the location of the textile semifinished product in the mold.
• the object is achieved by a semifinished textile product for producing a preform for a fiber composite component, which has on at least one fiber reinforcement layer a binder web based on long-chain reaction resins which are in the solid state at room temperature.
• the textile semi-finished product corresponds to the
• the binder web is based on long-chain reaction resins which are in the solid state at room temperature, in particular based on unhardened thermosets. This leads to a distribution of the binder by partial crumbling also within the fiber composite layer (s).
• the additional Verhakein single Spun fibers or fragments with the composite fiber layer (s) further increase the binding effect in the subsequent fixation of the preform shape.
• the web structure of the binder allows a good Drapiercite of the textile semifinished product, even in the cold state.
• the semi-finished textile product has a binder web with a
• Basis weight in the range of 3 g / m 2 to 10 g / m 2 , preferably from 5 g / m 2 to 7 g / m 2 , which is made possible by the special structure of the binder as a web.
• binders nonwoven layers with such a low basis weight are only available with difficulty and at very high costs, whereas such basis weights for binders can be achieved easily and inexpensively with the method described above.
• the binder web is applied in a discontinuous pattern, such as a dot or line pattern.
• a discontinuous pattern such as a dot or line pattern. This contributes to a low surface weight over the entire surface of the textile semifinished product, but at the same time allows a locally higher basis weight at points at which a particularly high binding effect is desired for the subsequent shape of the preform. This can be the case, for example, in the edge zone area.
• FIG. 1 shows a flow chart for the sequence of an embodiment of the method for producing a preform
• FIG. 2 schematically shows a first variant of the working steps for producing a semi-finished textile product as a precursor to the preform
• FIGS. 3a, b schematically show a detailed view of the structure of the weave in FIG.
• FIGS. 4a, b schematically show a second variant of the production steps
• FIGS. 5a, b show schematically ways of arranging the binder web on an underlying fiber layer
• FIG. 6 schematically shows a third variant of the working steps for producing a semi-finished textile product as a precursor to the preform.
• FIG. 1 shows the sequence of an embodiment of the method for producing a preform for a fiber composite component.
• Fiber reinforcement structure which has two fiber reinforcement layers, between which a binder web is arranged.
• the two fiber reinforcement layers are formed as gel layers, which together form a bidirectional scrim.
• the at least one fiber reinforcement layer may be formed as a scrim layers, scrims, woven, knitted, knitted, nonwoven, mat or braids, or a combination thereof.
• the scrims may be unidirectional, biaxial, bidirectional or multiaxial.
• the number and choice of the embodiment of the fiber reinforcement layer is determined primarily by the type and shape of the fiber composite component to be produced from the preform and the mechanical requirements imposed on it.
• Fiber reinforcement layer all fiber reinforcement layers equipped with binder web. Locally varying demands on the binding effect can be reacted by varying the density of the binder web. With more than two fiber reinforcement layers is advantageously between at least two
• Fiber reinforcement layers provided by the binder web.
• the fiber reinforcement layers are glass fibers, but they may also be carbon fibers, synthetic fibers, natural fibers, hybrid fibers, or combinations thereof.
• the type of fiber is advantageously takes into account which matrix resin in the further processing to a
• Fiber composite component will be used.
• a fiber reinforcement layer is formed (step 10 in FIG. 1).
• binder is applied by spraying as a web on the fiber reinforcement layer (step 12).
• the binder is preferably a non-cured thermoset-based binder.
• Particularly suitable longer molecule-chain resins have been found that are solid at room temperature and are also called hot melts, which is avoided by the application by spraying in web form a planar migration into the underlying fiber reinforcement layer and thereby good cold workability is possible.
• These are preferably epoxy resin systems without hardener.
• polyester or phenolic resin systems are also possible to use polyester or phenolic resin systems.
• the choice of binder material takes into account which matrix resin will be used in the further processing to form a fiber composite component. It is particularly advantageous to use resins which are based on the same monomers as the later matrix resin, although the polymers are shorter than the later matrix resin.
• a binder based on bisphenol A resins e.g. Shell's "Shell 1004" brand sprayed as a web
• novolaks are particularly preferably used as binders, all proposed solid resin systems without curing agents being used.
• the binder in order to spray the binder as a web, it may for example already be present in liquid form in a reservoir of a spraying device or between
• Reservoir and nozzle are liquefied by heating.
• the binder material cools and impinges on the fiber reinforcement layer in the partially or fully solidified state.
• the binder is characterized as fine
• Threaded web similar to cotton candy, or deposited as a thread of fine endless threads on the fiber reinforcement layer.
• Threaded web similar to cotton candy, or deposited as a thread of fine endless threads on the fiber reinforcement layer.
• binder web can be integrated, as it were, online through the spraying step into the production of the fiber reinforcement.
• an intermediate product is first prepared, which will be referred to hereinafter as semi-finished textile product and directly to a Preform can be further processed or stored and later, if necessary, can be further processed elsewhere.
• Process steps can be carried out continuously or discontinuously.
• the further processing of the semi-finished textile product to the preform comprises as essential steps the cold forming of the binder-spun fabric
• Fiber reinforcement layer (step 14) and the heating and subsequent
• step 16 Cooling the reshaped binderized fiber reinforcement layer (step 16).
• the textile semi-finished product is placed in a mold and draped there in such a way that it assumes this shape.
• a major advantage in terms of production, energy consumption and costs in terms of production technology is that this is possible at room temperature without warming up the textile semifinished product. Because the equipment with binder in web shape affects the textile properties of the fiber reinforcement layers and thus their formability only insignificantly.
• Heating with subsequent cooling is only necessary for fixing the mold.
• the binder is melted and solidified again, wherein the fiber reinforcement layers are kept in the desired shape.
• the heating, but also the cooling are carried out in particular by means of appropriately tempered air. This allows a special rapid temperature change.
• the preform can be removed from the mold. Possibly. it can still be aftertreated by surface treatments, singling or other processing steps. It can also be used as such in processes such as RTM (resin transfer molding) process, RIM (resin Injection molding method or other vacuum and / or pressure-assisted injection method are embedded in a mold in a matrix resin, the
• FIG. 2 schematically illustrates a first variant of the first steps of the production of a preform, specifically up to the production of the semi-finished textile product by means of the representative example of a two-way bidirectional fabric
• Bisphenol A resin base which is formed in the present example as a bidiagonal scrim.
• a first entry 101 of fiber reinforcement material is provided which forms a first fiberglass liner layer as a fiber reinforcement layer, the fiber reinforcement material i.a. can be supplied filiform or web-like.
• a binder web 107 is formed on the pad 101 using a sprayer 105 from which a swirling spray 109 exits.
• a second glass fiber layer layer is formed as a fiber reinforcement layer via a second entry 103. Both gel layers are arranged at + 45 ° and -45 ° to the direction indicated by the arrow machining direction and together form a bidiagonal scrim.
• Binder spun on bisphenol A resin-based bediagonal scrim is needle-punched or sewn for better handleability using the sewing or needle device 11.
• the needling is performed in particular to the two gel levels
• the binder web on unhardened Duroplastbasis already entangled by its brittleness with the underlying fiber reinforcement layer.
• the degree of solidification of the web upon impact can be changed.
• the web is not fully solidified when hitting the fiber reinforcement layer, so that at the contact points a kind of adhesive effect or a kind
• thermoset-based binder web also leads to partial crumbling so that web fragments also spread in the fiber reinforcing layer, resulting in mold fixing in the fiber-reinforced layer
• FIGS. 3 a, b in the plan view (FIG. 3 a) in the x-y plane and in section (FIG. 3 b) in the z-direction of a semifinished textile product 201, the structure of FIGS. 3 a, b, in the plan view (FIG. 3 a) in the x-y plane and in section (FIG. 3 b) in the z-direction of a semifinished textile product 201, the structure of FIGS. 3 a, b, in the plan view (FIG. 3 a) in the x-y plane and in section (FIG. 3 b) in the z-direction of a semifinished textile product 201, the structure of FIGS. 3 a, b, in the plan view (FIG. 3 a) in the x-y plane and in section (FIG. 3 b) in the z-direction of a semifinished textile product 201, the structure of FIGS. 3 a, b, in the plan view (
• Fiber reinforcement layer 205 is looked under which another, oriented in a different direction fiber reinforcement layer 203 is disposed.
• the fibrous fibers 207 have different lengths and curvatures and extend not only in the x-y plane but also perpendicular thereto in the z-direction. In part, they are broken into smaller fragments 209, as shown in the sectional view in Figure 3b, in which between two fiber reinforcement layers 205, 213 a binder web is arranged.
• the fragments 209 may be between the fibers of the
• Fiber reinforcement layer 205 trickle.
• Fiber reinforcing layers 205, 213 with each other fragments can also be pulled into the overlying fiber reinforcement layer 213.
• Spun fibers 207 connect to the fibers of the fiber reinforcement layer 205. How deep the spun fibers 207 penetrate into the adjacent fiber reinforcement layers 205 (in the z-direction example shown here) can be influenced by the brittleness of the binder material.
• FIGS. 4a, b a variant of the construction shown in FIG. 2 for producing a semifinished textile product is shown from the side (FIG. 4a) and from above (FIG. 4b).
• a first thread entry 301 on a in the arrow direction is shown from the side (FIG. 4a) and from above (FIG. 4b).
• Moving conveyor belt 305 a first fiber reinforcement layer 303 is formed. This is applied by means of a spraying device 307 with nozzle 309, from which forms a swirling spray jet 31 1, a binder web 313.
• the use of the conveyor belt 305 allows a high accuracy in depositing the first fiber reinforcement layer 303 and the application of the binder web 313.
• a second fiber reinforcement layer 315 is formed over the binder web 313 via a second thread entry 317.
• the fiber reinforcement layers 303, 315 with between lying binder web 313 are provided in the sewing device 319 with seams 323 and the textile semi-finished product 321 thus prepared is rolled up for further transport on a roll 325.
• the construction in FIGS. 4a, b differs from that shown in FIG. 2 in that the spray device 307 can be moved back and forth perpendicular to the transport direction of the treadmill 305 (indicated by the double arrow). This allows that
• Binder web 313 to apply as, for example, line pattern, as shown schematically and exemplified in the figures 5a, b. Any other disjoint pattern of application may also be selected.
• the web 505 is applied in a meandering line pattern on the fiber reinforcement layer 503.
• the web 515 is applied under relative movement of the
• Spraying device applied in parallel to the transport direction of the treadmill in a spiral line pattern on the fiber reinforcement layer 513.
• speed of the treadmill and speed of the spray can be very specific influence on the density of the web and its local basis weight take. In compliance with average basis weights of the
• Binders of 3 g / m 2 to 10 g / m 2 preferably from 5 g / m 2 to 7 g / m 2 can still achieve sufficient binder concentrations everywhere in order to produce more complex preforms can.
• the application in line patterns allows an optimized binding effect of the binder web without the application of a contiguous area of binder web would be necessary.
• the assignment with binder web depends on the fiber material, the
• Glass fiber multilayers with orientations of + 45 ° and -45 ° with intermediate web of binder preferably thermoset-based, for example on bisphenol A resin base, from which an L-profile with local spherical bulge would be produced, would be the largest part with about 5 -7 g / m 2 of binder spun. In the area of the spherical bulge, one would locally increase the binder concentration to about 10-12 g / m 2 , to the restoring forces of the fibers of the fiber reinforcement layers to dominate. Over the entire surface of the Glasmaschinegelege would
• Binder concentration on average below 10 g / m 2 .
• FIG. 6 shows a further variant of the structure from FIG. 2 for producing a semi-finished textile product as a precursor to the preform. It is a first
• Yarn entry 601 is provided, which is a first glass fiber layer as
• Fiber reinforcement layer forms.
• a binder web 607 is formed using a sprayer 605 from which a swirling spray 609 exits.
• a second thread entry 603 via a second thread entry 603 a second
• Glass fiber layer layer formed as a fiber reinforcement layer. Both gel layers are arranged at + 45 ° and -45 ° to the direction indicated by the arrow machining direction and together form a bidiagonal scrim.
• the web 623 of semi-finished textile made of binder with bobbin on bisphenol A resin-based bi-diagonal scrim is used for better handling using the
• the structure from FIG. 6 additionally has a scattering device 615 in order to add powdered additives 617 to the binder web 607 in the present example.
• the powder 617 of additives may, for example, be additives which influence the fire or flame behavior of the preform and of the fiber composite component produced therefrom. Also mechanical properties such as the toughness of the
• Fiber composite component can be influenced by the deliberate addition of additives as desired.
• the additive powder 617 can be fixed by means of a heating device 619, for example, by means of heat radiation 621 on the fiber reinforcement layer or in the binder web 607, in order to prevent excessively trickling out.
• the binder web can also form a higher number of contact points with the underlying fiber reinforcement layer.
• Binder material are added and sprayed together with this as a web.
• the additive (s) may also be in a separate
• additives that enhance the toughness of increase later fiber composite component also called Toughener, are often suitable for a job by spraying.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Nonwoven Fabrics (AREA)
• Reinforced Plastic Materials (AREA)
• Moulding By Coating Moulds (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

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• 2009
  • 2009-12-09 DE DE102009044834.9A patent/DE102009044834B4/de not_active Expired - Fee Related
• 2010
  • 2010-12-09 LT LTEP10790422.9T patent/LT2509759T/lt unknown
  • 2010-12-09 ES ES10790422.9T patent/ES2632362T3/es active Active
  • 2010-12-09 EP EP10790422.9A patent/EP2509759B1/de active Active
  • 2010-12-09 HU HUE10790422A patent/HUE034089T2/hu unknown
  • 2010-12-09 WO PCT/EP2010/069291 patent/WO2011070118A1/de active Application Filing
  • 2010-12-09 DK DK10790422.9T patent/DK2509759T3/en active
  • 2010-12-09 PT PT107904229T patent/PT2509759T/pt unknown

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