DE102014019220A1 - Method and device for producing a band-shaped semifinished product - Google Patents

Abstract

The invention relates to a method for producing a strip - shaped semifinished product (15) comprising reinforcing fibers and matrix material in asymmetrical distribution, comprising the following steps: arranging at least two fiber bundles (5, 7, 9) one above the other so that each fiber bundle (5, 7, 9 ) forms a layer, wherein at least a first layer of matrix fibers and at least a second layer of reinforcing fibers, and connecting the layers together to form a band-shaped semi-finished product (15).

Description

The invention relates to a method and an apparatus for producing a band-shaped semi-finished product.

From the international patent application with the publication number WO 2013/086258 A1 For example, a process for impregnating at least one fiber roving with a polymer resin to form an asymmetric belt is provided, essentially providing that the at least one fiber roving be impregnated with the polymer resin by extrusion, thereby ultimately forming the belt. This approach is cumbersome and limited in terms of achievable embodiments of the tape.

The invention has for its object to provide a method and an apparatus, wherein said disadvantages are avoided.

The object is achieved by providing the subject matters of the independent claims. Advantageous embodiments emerge from the dependent claims.

The object is achieved in particular by providing a method for producing a band-shaped semifinished product, wherein the band-shaped semifinished product comprises reinforcing fibers and matrix material in an asymmetrical distribution, and wherein the method comprises the following steps: at least two fiber bundles are arranged one above the other, so that each fiber bundle has one Layer forms. The term "on top of each other" particularly refers to the fact that the fiber bundles, with their broad sides extending perpendicular to a longitudinal direction, are overlapped at least in regions, preferably completely overlapping. At least a first layer of matrix fibers and at least one second layer of reinforcing fibers are formed. In particular, the first layer consists of matrix fibers, and the second layer consists of reinforcing fibers. Therefore, a band-shaped semi-finished product formed in this way has an asymmetrical distribution of fibers because the layer structure is separated into matrix fibers on the one hand and reinforcing fibers on the other hand. When arranging the fiber bundles one above the other, mixing of matrix fibers and reinforcing fibers is thus preferably at least largely avoided, wherein mixing is preferably completely avoided. The asymmetry of the band-shaped semifinished product results from the layer structure. The layers are finally connected together to form a band-shaped semi-finished product. In the context of the method, the matrix material is preferably introduced completely over the matrix fibers and not by extrusion. The method is easy to carry out and is not limited or at least to a much lesser extent with respect to the strip-shaped semi-finished products to be produced, as is the case known from the prior art.

In particular, an embodiment of the method is preferred in which the extrusion of matrix material is dispensed with. In particular, in this case shows that the matrix material is introduced exclusively via the matrix fibers in the band-shaped semifinished product, so that realize the advantages already described above in full.

However, in one embodiment of the method it is also possible for additional matrix material to be supplied by means of an extruder. However, in this case too, the main supply of matrix material preferably takes place through the matrix fibers.

The at least two fiber bundles are preferably unwound from at least two fiber spools, each fiber bundle being associated with a fiber spool from which the associated fiber bundle is unwound. In this case, in particular a first fiber coil has a fiber bundle, which consists of matrix fibers, wherein a second fiber coil has a fiber bundle, which consists of reinforcing fibers. Thus, the different fibers are already completely separated from each other in terms of their design and function on the fiber bobbins, which facilitates the asymmetric layer structure of the band-shaped semifinished product.

In the context of the method, fiber bundles are preferably combined with one another such that the band-shaped semi-finished product finally has a fiber volume content of reinforcing fibers to matrix material of preferably approximately 47% to approximately 53%.

An embodiment of the method is preferred, which is distinguished by the fact that several, preferably identical fiber bundles are juxtaposed and preferably glued together. In this way, a width of the resulting band-shaped semi-finished product is flexible and adjustable in the desired manner. In this case, preferably the juxtaposed fiber bundles partially overlap, so that they can be glued together in an overlap region. Thus, given a fiber bundle width, it is possible to produce a band-shaped semifinished product of almost twice the width, based on the width of the individual fiber bundles, by juxtaposing two identical fiber bundles with slight overlap. The width of the resulting band-shaped semi-finished product is then equal to twice the width of the individual fiber bundles minus the Overlap region. Of course, such a juxtaposition and bonding of fiber bundles is preferably carried out in layers, so that in each layer an equal width of the resulting band-shaped semi-finished product is realized. This results in a total of the entire layer structure homogeneously wide, band-shaped semi-finished product.

If two or more fiber bundles - viewed in the width direction - arranged side by side, they are preferably combined offset in height, so that a slight overlap in the edge region is possible. The juxtaposed fiber bundles are then overlapped on one another and connected to form a layer of the band-shaped semifinished product.

As part of the method, fiber bundles are preferably used, which have a substantially rectangular, preferably rectangular cross-section. Such fiber bundles exist as prefabricated rovings and can be used as far as possible within the scope of the method. They have in a cross-sectional plane perpendicular to its longitudinal extent seen a height and a width, wherein the width is preferably greater than the height. As part of the process, different fiber bundles are preferably arranged one above the other in the vertical direction, so that they lie on one another with their broad sides. In order to increase the width of the resulting ribbon-shaped semifinished product, it is possible to arrange identical fiber bundles in the width direction next to one another in each layer, optionally with slight overlap. These fiber bundles can then be glued together.

The process preferably uses standard reinforcing fiber bundles, in particular standard glass rovings or standard carbon fiber rovings with a standardized number of fibers, to produce strip-shaped semi-finished products of arbitrary width. In this case, preferably several of these standard rovings are fanned out and put together. The juxtaposed rovings are - as already stated - interconnected, in particular glued together.

Preferably, rovings are used which, seen in a cross-sectional plane perpendicular to the longitudinal direction of the rovings, have about 9 filaments in a height direction, having about 385 filaments in a widthwise direction in the cross-sectional plane. It is also possible to use rovings having 7 to 8 filaments in the height direction, having about 485 filaments in the width direction. Such rovings can be placed next to each other to increase the width of the resulting band-shaped semi-finished product. In this case, a resulting ribbon-shaped semi-finished product, for example, in the width direction about 970 filaments.

It is possible that a partially consolidated, ribbon-shaped semi-finished product has a height of at least 0.3 mm to at most 1.0 mm, preferably from at least 0.4 mm to at most 0.6 mm, preferably of 0.5 mm. The width of such a partially consolidated band-shaped semi-finished product may preferably be 6.35 mm. Alternatively, it is also possible that the width is about 8 mm or about 16 mm.

A height of a fully consolidated ribbon-shaped semi-finished product is preferably about 0.15 mm or 0.12 mm. The width of a fully consolidated semi-finished product may preferably be 6.35 mm, 8 mm or, if a plurality of standard rovings are juxtaposed, approximately 16 mm.

The process preferably uses matrix fibers which comprise a material or consist of a material selected from a group consisting of polyamide (PA), in particular PA 6 or PA 6.6, and polyphthalamide (PPA). The material is particularly preferably selected from a group consisting of PA 6 and PPA. A preferred matrix system is Lanxess Durethan B30S. The matrix fibers are preferably provided as a multifilament yarn on a fiber bobbin. Preferably, the multifilament yarn has a fineness of 300 tex f 280 without rotation, without turbulence on. Alternatively, it is possible that the multifilament yarn has a fineness of 600 tex.

In a preferred embodiment of the method, reinforcing fibers are used which comprise a material or consist of a material which is selected from a group consisting of glass and carbon. It is particularly preferred to use glass fibers and / or carbon fibers. The reinforcing fibers are preferably provided as a multifilament roving on a fiber bobbin. For glass fibers, a material is preferably used which has an LOI value (loss on ignition) of at least 0.1% to at most 0.5%, preferably from at least 0.15% to at most 0.3%. Also for carbon fibers, low LOI values are preferred, preferably in the preferred ranges given for glass. The glass fiber rovings particularly preferably have a fineness of 1200 tex. Carbon fiber rovings preferably have a fineness of 12 k, corresponding to 800 tex.

In the context of the method, a combination of reinforcing fibers and matrix fibers is particularly preferably used, wherein Reinforcing fibers Glass fiber rovings with a fineness of 1200 tex, and as reinforcement fiber rovings a PA 6 filament yarn with a fineness of 600 tex is used. In another particularly preferred embodiment of the process, a carbon roving having a fineness of 12 k, corresponding to 800 tex, and as reinforcing fibers a PA 6 filament yarn having a fineness of 600 tex is used as the reinforcing fiber.

An embodiment of the method is preferred, which is characterized in that the layers arranged one above the other are joined together by a sizing. This represents a simple and at the same time very suitable way of interconnecting the layers before a partial consolidation or complete consolidation of the strip-shaped semifinished product. It is possible to produce the band-shaped semi-finished product with different degrees of consolidation, in particular unconsolidated, partially consolidated or fully consolidated. The band-shaped semi-finished product holds together in each of these states of consolidation, in particular through the sizing. Preferably, the layers are glued together by the sizing. The size also causes a better connection of the reinforcing fibers with the matrix fiber material in the consolidation or Teilkonsolidieren the band-shaped semi-finished product.

Preferably, juxtaposed fiber bundles are connected to one another by means of a sizing to increase the width of the band-shaped semifinished product, in particular glued together.

Preferably, the process uses a size which is not crosslinked and is therefore still reactive. Particularly preferably, the size is soluble again with aqueous media.

An embodiment of the method is preferred, which is characterized in that the band-shaped semi-finished product is further processed unconsolidated. The band-shaped semi-finished product is preferably held together only by the sizing in this case. Incidentally, in the unconsolidated state, reinforcing fibers and matrix fibers are unfused next to each other. Such a band-shaped semi-finished product is very flexible and can therefore be used in a particularly diverse manner and especially even at very high degrees of deformation. However, if several layers of such a ribbon-shaped semifinished product are superimposed and then consolidated in a production of a component, this requires a very large amount of time, because a thick layer of fibers must be melted and impregnated.

Alternatively or additionally, as part of the process, the band-shaped semi-finished product is partially consolidated. In this case, the matrix fibers are not completely, but only partially melted, so that reinforcing fibers and matrix fibers are partially and in particular partially interconnected. As a result, the band-shaped semi-finished product is stabilized on the one hand, but on the other hand still has a high degree of flexibility. So it is still suitable for relatively high degrees of deformation, without being unstable or need a time-consuming Fertigkonsolidierung, as is the case with an unconsolidated band-shaped semi-finished product. Such a partially consolidated or partially impregnated semi-finished product is preferably used for laying components, for example by draping it into a forming tool or injection-molding tool and then reshaping and / or extrusion-coating it and thereby preferably completely consolidating it. It can be realized relatively high degrees of deformation.

In connection with a partial consolidation or partial impregnation also shows the following: The thermoplastic matrix is then partially present as a yarn, in part, the consolidation, that is, the melting and bonding with the reinforcing fibers into a solid composite material but already done. The result is a high, homogeneous application of the matrix and short flow paths for the same. Scraping of the matrix is prevented. Especially with more than three-layer structures only a pre-impregnation in favor of the formability of the semifinished product can be carried out, because in this case still high degrees of deformation are possible. Full impregnation preferably takes place subsequently in an injection molding process and / or in a forming process. By partial consolidation still unfilled gaps remain in the band-shaped semi-finished product, resulting in the better drapability of the semifinished product. Furthermore, no voltages are frozen, so that in particular no spiral spring effect results during winding or winding. This contributes significantly to increased occupational safety in dealing with the band-shaped semi-finished product.

Alternatively or additionally, the band-shaped semifinished product is completely consolidated in the context of the method. In particular, the strip-shaped semifinished product is preferably further used in a fully consolidated manner. A ribbon-shaped semi-finished product produced in this way is very stiff. It has in particular the properties of a spiral spring. Such a band-shaped semi-finished product is preferably used for winding or braiding.

An embodiment of the method is also preferred, which is characterized in that at least three layers are formed. In this case, according to one embodiment of the method, it is provided that at least two outer layers consist of matrix fibers, wherein at least one inner layer consists of reinforcing fibers. Particularly preferred is an exactly three-layered structure, wherein only three layers are formed, wherein the two outer layers consist of matrix fibers, and wherein an inner layer disposed between the two outer layers consists of reinforcing fibers.

A layer construction in which external layers of matrix fibers are seen is particularly suitable for winding. During winding of the band-shaped semifinished product, namely a scraping of the reinforcing fibers, ie in particular a violation of the same, must be avoided. Therefore, a band-shaped semi-finished product to be used for winding preferably has a core of reinforcing fibers and matrix material-enriched edge layers which protect the reinforcing fibers from abrasion.

Such a band-shaped semi-finished product used for winding is preferably completely consolidated. It is then stiff and contains no voids or other defects or imperfections. It is preferably wound up after its production on a spool. In this case, matrix material also penetrates into the layers, which previously consist of reinforcing fibers.

The fact that layers consist of reinforcing fibers or of matrix fibers therefore relates, in particular, to the arrangement before consolidation of the band-shaped semifinished product, after unwinding of the fiber bundles and the stacking of the layers. However, the consolidated strip-shaped semifinished product has a strongly asymmetrical distribution of the reinforcing fibers on the one hand and of the matrix material on the other hand, in particular in the form of the layers explained above.

Alternatively, in the context of the method, an at least three-layer structure is realized in which at least two outer layers consist of reinforcing fibers, wherein at least one inner layer consists of matrix fibers. Particularly preferred is an exactly three-layer structure, that is, a layer structure with only three layers, which has exactly two outer layers of reinforcing fibers, wherein between the two outer layers an inner layer is provided which consists of matrix fibers.

Such a layer construction comprising outer layers of reinforcing fibers and a core of matrix fibers is preferably used for braiding. If pipes or other structures are to be braided later from a strip-shaped semi-finished product, the strip-shaped semi-finished product is typically guided through a braiding head or a braiding wheel, whereby the ribbon-shaped semi-finished product is strongly pressed. If there is too much matrix material in its outer area, ie in the outer layers, it is scraped off in the braiding head, where it can fall down and contaminate the braiding head. Ribbon-shaped semi-finished products which are to be used for braiding therefore preferably have reinforcing fibers in their outer layers, which protect the inner matrix layer from abrasion.

Also intended for braiding, band-shaped semi-finished products are preferably completely consolidated and wound up on a spool. This results in the already mentioned advantages.

Alternatively, an embodiment of the method is preferred, wherein a multi-layered, alternating sequence of layers of matrix fibers and reinforcing fibers is formed. It is particularly preferred that an alternating sequence of more than three layers of matrix fibers and reinforcing fibers is provided. With such a layer structure, the band-shaped semifinished product can be adapted to a later use in a particularly flexible and versatile manner.

Preference is given to a multilayered layer structure with an alternating sequence of layers, wherein reinforcing fibers are arranged in outer layers, which are also referred to as edge layers. In particular, the edge layers preferably consist of reinforcing fibers. In the process, very particularly preferably, five layers are arranged one above the other, wherein-seen along the layer sequence from an outer edge layer-a first layer of reinforcing fibers, a second layer of matrix fibers, a third layer of reinforcing fibers, a fourth layer of matrix fibers, and a fifth layer of reinforcing fibers are provided, wherein the layers are preferably made of the fibers mentioned here.

Such a multi-layered strip-shaped semifinished product, in particular having more than three layers, is preferably used for laying.

Such a multi-layer, strip-shaped semifinished product, in particular with more than three layers, is particularly preferably partially consolidated, as a result of which a strip-shaped semifinished product which on the one hand is solid but on the other hand also very readily deformable is obtained. The strip-shaped semifinished product produced in this way is in particular limp, which and can be readily formed. For the production of a component is the preconsolidated, band-shaped semi-finished product preferably placed and then brought into a final mold in a press tool or in an injection mold. This is then - in particular under pressure and elevated temperature - a full consolidation. It is possible, for example, to form patches from a preconsolidated, band-shaped semi-finished product into corner regions in order to produce a multifunctional recess. When closing a forming tool, these patches then weld to a remaining component.

It is also preferred an embodiment of the method, which is characterized in that the band-shaped semi-finished product is wound. In this case - as already stated - preferably a - in particular exactly three-layer - construction with two outer layers of matrix fibers and at least one inner layer of reinforcing fibers used. Preferably, in this way, a roof cap, in particular for a convertible, or a front end support, in particular for a passenger car or a truck made. It is possible that a component produced in this way is subjected to a hydroforming process and / or an encapsulation with plastic for the production of connecting elements. It turns out that the band-shaped semi-finished product must be very uniform and in particular must have a high-precision width in order to be able to produce high-quality components by winding. It also shows that during winding - as well as laying - no ondulation of the band-shaped semi-finished product takes place. A wound structure is therefore poorly deformable in later process steps.

Alternatively, an embodiment of the method is preferred in which the band-shaped semi-finished product is braided. In this case - as stated above - preferably a layer structure with at least three - preferably exactly three - layers is used, wherein two outer layers of reinforcing fibers, wherein at least one inner layer of matrix fibers exists. During braiding, the reinforcing fibers provided in the edge region protect the inner matrix layer from abrasion. A braided ribbon-shaped semi-finished fiber product is preferably used to produce a cross member for a motor vehicle, in particular for arrangement below a cockpit. It is also possible that such a cross member for arrangement in the region of an instrument panel, in particular under an instrument panel of a motor vehicle, is produced. Such, produced by braiding cross member is well formed, especially in the area of a steering console of the motor vehicle. In this case, the cross member can be reshaped in particular by hydroforming. In addition, it is possible to overmould him with plastic, in particular connecting elements can be molded onto adjacent components of a motor vehicle body to the cross member.

When braiding an ondulation of the band-shaped semi-finished product takes place. The braided structure has similar properties as a fabric. It can be reshaped better than a wrapped structure.

Alternatively, an embodiment of the method is preferred, which is characterized in that the band-shaped semi-finished product is placed. In this case, it is preferable to use a multilayer structure, in particular having more than three layers, which has an alternating sequence of layers of matrix fibers and reinforcing fibers. In this case, reinforcing fibers are preferably provided in outer layers. A band-shaped semi-finished product intended for laying is preferably only partially impregnated or partially consolidated. In this way it is limp, soft and easy to form. It can therefore be laid and then brought into its final shape in a press tool or injection mold. It is also preferred - under pressure and elevated temperature - a full consolidation.

By laying the band-shaped semi-finished product is preferably a trunk cavity, a parcel shelf, a multi-function tray, a front flap, in particular for a truck, a support for a front flap, or a hybrid part with fiber-reinforced plastic, in particular in conjunction with an organic sheet manufactured. A carrier produced in this way is preferably formed by hydroforming, wherein particularly preferably connecting elements are molded onto the carrier by injection molding. To produce a multi-function tray, patches of preconsolidated strip-shaped semi-finished products can be shaped into corner areas, for example for producing a hat rack or trunk cavity. When closing a forming tool, these patches weld to a remaining component.

Overall, it is found that the band-shaped semi-finished product is preferably used for producing a fiber-reinforced component or for producing a component made of fiber-reinforced plastic.

It also shows that the method preferably does not end with the production of the band-shaped semi-finished product, but rather also relates to its use for producing a component. It is therefore preferably a method for the production and further processing of a band-shaped semifinished product, in particular a method for producing a component by means of the band-shaped semifinished product.

An embodiment of the method is also preferred, which is characterized in that matrix fibers with embedded nanoferrites are used, wherein the embedded nanoferrites are stimulated to consolidate the band-shaped semifinished product. In this case, the matrix material of the matrix fibers preferably comprises nanoferrites from Evonik Magsilica. For the matrix fibers, a matrix system of PA 6, in particular Lanxess Durethan B30S, with nanoferrites from Evonik Magsilica is particularly preferably used. Alternatively or additionally, a matrix system made of PPA with nanoferrites from Evonik Magsilica is preferably used. For heating and thus partial consolidation or complete consolidation of the ribbon-shaped semifinished product, the nanoferrites are preferably excited by microwave radiation or by induction. Nanoferrites offer a particularly favorable opportunity for melting or consolidating or partially consolidating a hybrid roving. Embedded in the matrix fibers are nanoferrites, which are excited by induction or microwave radiation and thus cause the material to heat up. This is a volumetric heating, so that the temperature can be set very well. This is preferably done by selective choice of a density and / or number of nanoferrites in the matrix material. Overheating can be avoided. This embodiment of the method makes it possible to ensure very well that only one, preferably very homogeneous, partial consolidation takes place in a pultrusion process. This is the case in particular because, by adjusting the density or number of nanoferrites in the matrix material on the one hand and by selecting the irradiated microwave power or inductive power, a temperature which is always adapted and useful for the selected task can be set in the material to be partially consolidated or consolidated ,

Particularly preferably, the matrix fibers are mixed with 3 wt .-% nanoferrites. This allows for efficient inductive or microwave induced volumetric heating before and in an impregnation zone. Only the matrix material and not the sizing are heated. The cross-linking of the size takes place later and promotes / facilitates a melt impregnation. Induction heating by means of nanoferrites reduces energy costs and allows a higher flow rate than when using infrared radiation. The nanoparticles reduce the viscosity of the matrix melt so that it flows more easily, and facilitate the impregnation, in particular a sheathing of each individual filament of the reinforcing fibers.

An embodiment of the method is possible in which, in addition or as an alternative to the inductive heating or the heating by means of microwaves, heating takes place by means of infrared radiation. Furthermore, it is possible that the sizing is dried by heating by infrared radiation.

In a preferred embodiment of the method, the band-shaped semi-finished product is produced by embedding a layer of reinforcing fibers between layers of thermoplastic fibers. In this case, the individual fiber bundles are spread and placed on each other, being guided over a roller, by means of which the fibers are provided with a liquid sizing. It is important that the reinforcing fibers are wetted with sizing. This acts as an adhesive so that the thermoplastic later adheres well to the surface of the reinforcing fibers. The sizing is then dried. Then the matrix material - namely the thermoplastic fibers - is melted. In a subsequent pultrusion device, the thermoplastic is melted and then cooled and thereby fixed, that is brought to a desired level. In this case, the width of the band-shaped semi-finished product can be adjusted with high accuracy. It is then preferably either a partial consolidation or a complete consolidation, the strip-shaped semifinished product produced in this way is rigid in a Vollkonsolidierung and contains no voids or other defects and defects more. The finished, band-shaped semi-finished product is preferably wound onto a spool.

The invention also includes a band-shaped semi-finished product having a multilayer construction with asymmetric distribution of reinforcing fibers and matrix material, made by arranging at least two fiber bundles one above the other so that each fiber bundle forms a layer, wherein at least a first layer of matrix fibers and at least one second layer consists of reinforcing fibers, wherein the layers are joined together to form the band-shaped semi-finished product. Particularly preferably, the band-shaped semi-finished product is produced according to one of the previously described embodiments of the manufacturing method. The advantages that have already been explained in connection with the method are realized.

Particularly preferred for the band-shaped semi-finished product is an at least three-layered structure, in particular exactly three-layered, wherein two outer layers of matrix fibers are provided, in particular before consolidation, according to a first exemplary embodiment, wherein an inner layer of reinforcing fibers is provided, wherein according to a second embodiment Embodiment at least two outer layers of reinforcing fibers are provided, wherein at least one inner layer of matrix fibers is provided, and wherein according to a third embodiment, a multi-layer, in particular more than three-layer construction is provided with an alternating sequence of layers of matrix fibers and reinforcing fibers.

The band-shaped semifinished product is preferably characterized by at least one feature, which is due to at least one method step of one of the previously explained preferred embodiments of the method.

The object is also achieved by providing an apparatus for producing a band-shaped semifinished product, which comprises reinforcing fibers and matrix material in asymmetric distribution, wherein the apparatus has an unwinding device, which is arranged for unwinding at least one matrix fiber bundle and at least one reinforcing fiber bundle. The device has a laying device which is set up for arranging the fiber bundles in layers one above the other. The apparatus also includes a pultrusion device configured to at least partially reflow the matrix fibers. By means of the pultrusion device a partial consolidation or a complete consolidation of the band-shaped semi-finished product is possible. But it is also possible not to use the pultrusion device and / or not to activate or not to heat, so that an unconsolidated, strip-shaped semi-finished fiber is formed. In connection with the device, the advantages that have already been explained in connection with the method are realized.

The device is preferably free of an extrusion device and in particular free of a device with which additional matrix material could be supplied to the strip-shaped semifinished product. With the aid of the device, the matrix material is thus preferably introduced completely via the at least one matrix fiber bundle. Alternatively, however, it is also possible for the device to have an extrusion device in order to supply additional matrix material to the strip-shaped semifinished product, at least to a small extent. However, it is preferably provided that a major amount of matrix material is introduced through the at least one matrix fiber bundle.

A preferred embodiment of the device has a take-off device with which the belt-shaped semi-finished product coming from the pultrusion device is withdrawn and, viewed in the direction of production and thus the longitudinal direction thereof, can be conveyed through the device and in particular through the pultrusion device.

A preferred embodiment of the device has a take-up device, which is set up to wind up the strip-shaped semifinished product produced. This is then transported in a particularly favorable manner and / or storable.

A preferred embodiment of the device comprises a spreading device which is adapted to set a width of the fiber bundles. Preferably, each fiber bundle is assigned a separate spreading device. In particular, a width of the band-shaped semi-finished product is also adjustable over the width of the fiber bundles. Particularly preferably, a width of at least 6 mm to at most 16 mm, preferably from at least 8 mm to at most 16 mm, is selected for the fiber bundles.

The spreading device preferably has a plurality of godets, particularly preferably a multi-stage, counter-rotating godet web. In this case, a fixed galette and an opposite, movable and preferably force-controlled galette are preferably arranged on both sides of the fiber bundles. Preferably, such a controllable godet pair is realized, which for measuring and / or for adjusting the fiber bundle width and preferably also for improving the spread - in particular force-controlled. In this case, at least one godet pair is preferably convex or concave in profile. Particularly preferably, in a pair of godets, a convex godet is paired with a concave godet.

The peripheral speed of the godets corresponds to the fiber bundle speed in the device. The fiber bundle width and also the spread of the fiber bundles is set by the force exerted by a godet pair and the godet cross section of the godet pair.

Preferably, the fiber bundles are also held by the godet web to tension, the voltage is particularly preferably controlled constant. It is possible to improve by an alternating pressure load on the individual godets a preimpregnation or impregnation. By an alternating pressure load on the godets, the spread of the fiber bundles is improved.

Particularly preferably, the spreader has a plurality of opposing godets, which are arranged at a small distance from each other - viewed opposite to each other along a fiber bundle.

An embodiment of the device is also preferred, which is characterized by a splicing device which is set up for separating and connecting fiber bundles. In this case, fiber bundles can in particular be knotlessly interconnected by means of the splicing device. This is preferably done with the use of multiple fiber bobbins so that never more fiber bundles strands are divided and reconnected at the same time, but temporally offset so that always enough fiber bundle strands are available, which can absorb the withdrawal forces, with a tearing of the fiber bundles is prevented. The device is thus preferably operated so that the different fiber spools, from which the fiber bundles are unwound, idle at different times and, correspondingly at different times, separate fiber bundles from idle spools and connect them to fiber bundles of new spools.

The splicing device is preferably set up for the knotless connection of fiber bundles by means of compressed air, mechanical interweaving, bonding, or welding, in particular by means of ultrasound or laser beam.

An embodiment of the device is also preferred, which is characterized by a pultrusion device which has a heating device which has a microwave source and / or an induction device. The pultrusion device is then adapted for volumetric heating of matrix fibers having embedded nanoferrites. Additionally or alternatively, it is possible that the heating device has at least one infrared radiator.

The pultrusion device preferably has a vibration excitation device for improving the process stability, so that the pultrusion device and also the fiber bundles or the band-shaped semi-finished product can be excited to vibrate. This reduces the adhesion of the band-shaped semifinished product in the pultrusion device. The vibration excitation device is preferably set up for ultrasound excitation of the pultrusion device transversely and / or longitudinally to the process direction, thus to the withdrawal direction of the band-shaped semifinished product.

A complete impregnation of the thermoplastic fiber reinforcement fibers in the pultrusion can be ensured in particular as follows: It is possible to spread the filaments in order to achieve a good penetration of the filament bundle, which is particularly suitable for viscous impregnation media. Alternatively or additionally, a penetration of the filament bundle can be achieved by a high media pressure in the pultrusion device and / or by increasing the media pressure from an inlet to an exit of the pultrusion device. When passing through a pultrusion device, which decreases in cross-section, a medium pressure builds up from the inlet to the narrowest point, since the molten matrix material is entrained by the reinforcing fibers. As a result of this pressure increase, air is forced out of the cavities by matrix material and can escape through the inlet opening. In this way, a complete impregnation of the reinforcing fiber filaments with matrix material is achieved in the pultrusion device. The medium temperature preferably corresponds to a melt temperature in the pultrusion device. In order to achieve good flowability, but no damage to the matrix material, it is preferable to select media temperatures of at least 260 ° C. to not more than 280 ° C. in the case of PA 6. For PPA, preference is given to media temperatures above 300 ° C. and recommendations for processing of PPA by injection molding. A uniform wetting of all filaments can preferably be promoted by foaming the matrix material.

The description of the manufacturing method on the one hand and the device for producing the band-shaped semi-finished product on the other hand are to be understood as complementary to each other. Features of the device that have been described explicitly or implicitly in connection with the manufacturing method are preferably individually or combined with each other features of a preferred embodiment of the device. Procedural steps that have been described explicitly or implicitly in connection with the device are preferably individually or combined with each other steps of a preferred embodiment of the method. This is preferably characterized by at least one method step, which is due to at least one feature of the device. The device is preferably characterized by at least one feature, which is due to at least one method step of a preferred embodiment of the production method.

The invention will be explained in more detail below with reference to the drawing.

Showing:

1 a schematic representation of an embodiment of an apparatus for producing a band-shaped semi-finished product;

2 a detailed view of the embodiment of the device according to 1 ;

3 a further detail of the embodiment of the device according to 1 , and

4 a further detail of the embodiment of the device according to 1 ,

1 shows a schematic representation of an embodiment of a device 1 for producing a band-shaped semi-finished product which has reinforcing fibers and matrix material in asymmetrical distribution. The device has an unwinding device 3 which is set up to process a plurality of fiber bundles, here a first fiber bundle 5 a second fiber bundle 7 and a third fiber bundle 9 , The fiber bundles 5 . 7 . 9 comprise at least one matrix fiber bundle and at least one reinforcing fiber bundle.

The device 1 also has a laying device 11 which is arranged to arrange the fiber bundles 5 . 7 . 9 in layers one above the other. In addition, the device 1 a pultrusion device 13 configured to at least partially melt matrix fibers of a matrix fiber bundle. In particular, the pultrusion device 13 set up to the resulting band-shaped semi-finished product 15 at least partially consolidate or fully consolidate. It is possible that the pultrusion device 13 is deactivated to an unconsolidated band-shaped semi-finished product 15 to create.

The unwinding device 3 points here for each fiber bundle 5 . 7 . 9 in each case a fiber coil, namely a first fiber coil 17 , a second fiber coil 19 , and a third fiber coil 21 , As part of the process for producing the band-shaped semi-finished product 15 become the fiber bundles 5 . 7 . 9 each from the fiber coils 17 . 19 . 21 settled. Here are the fiber coils 17 . 19 . 21 arranged one above the other.

The device 1 has a splicing device 23 which is arranged to separate and connect the fiber bundles 5 . 7 . 9 , This serves in particular to the fiber coils 17 . 19 . 21 to replace with spare spools when the fiber spools 17 . 19 . 21 drain. It is in 1 shown that behind the fiber spools 17 . 19 . 21 spare spools 25 are arranged, when emptying the fiber coils 17 . 19 . 21 can be placed in their position to replace them. The method for producing the band-shaped semi-finished product 15 is preferably performed so that the individual fiber coils 17 . 19 . 21 not idle at the same time, in particular always only one of the fiber coils 17 . 19 . 21 using the splicing device 23 through a spare spool 25 is replaced.

The unwinding device 3 has at least two fiber spools. But it is quite possible that they are more than those in 1 Having shown three fiber coils, in particular when a multi-layered, ribbon-shaped semi-finished product is to be produced, which has more than three layers.

On each of the fiber coils 17 . 19 . 21 either reinforcing fibers or matrix fibers are wound up. So can from the fiber coils 17 . 19 . 21 pure reinforcing fiber bundles or pure matrix fiber bundles are unwound, which are arranged one above the other in layers. In this way, an asymmetric distribution in the form of a layer structure in the resulting band-shaped semifinished product 15 realizable.

In a first embodiment of the manufacturing method for producing the band-shaped semifinished product 15 is it possible that the first fiber coil 17 and the third fiber coil 21 Have matrix fiber bundles. The first fiber bundle 5 and the third fiber bundle 9 are therefore pure matrix fiber bundles. The second fiber coil 19 has a reinforcing fiber bundle, so that the second fiber bundle 7 is a pure reinforcing fiber bundle. The fiber bundles 5 . 7 . 9 In this embodiment of the method, layers are arranged one above the other in such a way that a layer structure of two outer layers of matrix fibers and an inner layer of reinforcing fibers is formed. Such produced, band-shaped semi-finished product 15 is particularly suitable for winding.

In a second embodiment of the method, the first fiber coil 17 and the third fiber coil 21 preferably reinforcing fibers, so that the first fiber bundle 5 and the third fiber bundle 9 pure reinforcing fiber bundles are. The second fiber coil 19 preferably has matrix fibers, so that the second fiber bundle 7 is a pure matrix fiber bundle. In this way, a band-shaped semi-finished product 15 made of two outer layers of reinforcing fibers and an inner layer of matrix fibers. This band-shaped semi-finished product 15 is especially suitable for weaving.

Also possible is a multilayer structure with more than three layers and in particular alternating sequence of layers of matrix fibers and reinforcing fibers. In particular, a third embodiment of the method is preferred, in which five fiber coils are arranged one above the other and correspondingly five fiber bundles are unwound from the fiber coils. In this case, two outer fiber coils preferably have reinforcing fibers, the layer sequence then alternately a reinforcing fiber bundle, a matrix fiber bundle, a reinforcing fiber bundle, a matrix fiber bundle and again having a reinforcing fiber bundle. Such a formed band-shaped semi-finished product 15 is preferred in the pultrusion device 13 only partially consolidated and is particularly suitable for laying.

The pultrusion device 13 preferably has an in 1 Heating device, not shown, which preferably has a microwave source for volumetric heating embedded in the matrix fibers Nanoferriten. Alternatively or additionally, the heating device preferably has an induction device, which is likewise designed for volumetric heating of nanoforces embedded in the matrix fibers.

The device 1 preferably has a spreader 27 configured to set a width of the fiber bundles 5 . 7 . 9 , This is at the same time a width of the band-shaped semi-finished product 15 total adjustable.

Incidentally, it is possible for a plurality of identical fiber bundles to be arranged side by side, in particular with at least slight overlap, in order to produce wider, in particular multiply wide, semi-finished fiber products. For this purpose, corresponding fiber coils with identical fiber bundles above or next to each other at the unwinding device 3 be provided.

The device 1 also has a sizing device 29 which is adapted to apply a size to the fiber bundles 5 . 7 . 9 , The sizing serves as an adhesive, on the one hand, the fiber bundles 5 . 7 . 9 and thus the different layers of the band-shaped semifinished fiber product 15 on the other hand, to improve the adhesion of the thermoplastic matrix to the surface of the reinforcing fibers. The sizing is preferably carried out in a drying device 31 dried. At the same time it is possible that the matrix fibers already in the drying device 31 be at least partially melted, creating a prefixing of the fiber bundles 5 . 7 . 9 and thus the layers are relative to each other. In the pultrusion device 13 then takes place a partial or complete melting of the matrix fibers, and cooling and fixing the band-shaped semi-finished product 15 This is preferably brought exactly to the desired level. In this case, in particular, a width of the band-shaped semi-finished product 15 be set with high accuracy.

The device 1 further preferably has a trigger device 33 on, which for the withdrawal of the band-shaped semi-finished product 15 and in particular for conveying the same along the process direction of the device 1 is set up. In addition, the device 1 preferably a winding device 35 on, which is set up for winding the band-shaped semi-finished product 15 on a reel 37 ,

2 shows a schematic representation of a detail of the device 1 according to 1 , Identical and functionally identical elements are provided with the same reference numerals, so that reference is made to the preceding description. It shows 2a) a plan view of the device 1 and in particular to the laying device 11 , It is shown here that three identical fiber bundles, for example, according to the first fiber bundle 5 , so here's a first first fiber bundle 5 , a second first fiber bundle 5 ' and a third first fiber bundle 5 '' , are arranged side by side to a multi-wide, band-shaped semi-finished product 15 manufacture. It is in the plan view of 2a) to recognize that the corresponding fiber bundles 5 . 5 ' . 5 '' be arranged side by side, especially with slight overlap.

2 B) shows a side view of the device 1 , It turns out that the fiber bundles 5 . 5 ' . 5 '' offset in height to each other in the laying device 11 be guided so that they can be superposed with slight overlap in the edge region and so can be connected to a multiple-width layer.

3 shows a further schematic detail of the embodiment of the device 1 according to 1 , Identical and functionally identical elements are provided with the same reference numerals, so that reference is made to the preceding description. It shows 3 in particular a detailed view of the spreading device 27 , which also serves to bias the fiber bundles. This is schematic and exemplary for the first fiber bundle 5 shown. The spreader 27 in this case has a multi-stage, counter-rotating godet track, here offset to each other godets 39 are shown. In this case, the fiber bundle 5 in particular voltage constant are kept at a predetermined voltage, wherein an alternating pressure load on the godets 39 Impregnation or pre-impregnation can be improved. Furthermore, the spread is improved.

The godet track preferably has - what in 3 not shown - a combination of opposing godets, which form pairs of godets, wherein fixed godets are combined with movable, in particular force-controlled godets. In particular, the godet track preferably has a multiplicity of counter-rotating godets, which are arranged at a small distance from one another.

4 shows a further detailed representation of the device 1 , in particular the spreader 27 , Identical and functionally identical elements are provided with the same reference numerals, so that reference is made to the preceding description. It is at 4a) a first galette 39 represented, which is concave in profile. As already stated, the godets form a combination of a movable, force-controlled godet and a stationary godet. The paired godets are preferably shaped complementary to one another. In 4a) becomes the illustrated godet 39 against its associated complementary galette, which is not shown, with a first predetermined force F pressed. This results in a certain fiber bundle width, here, for example, the first fiber bundle 5 one. In 4b) is shown that the galette 39 is pressed with a second predetermined force against its associated complementary galette, which twice the first predetermined force F corresponds. In this case, the width of the first fiber bundle 5 reduced, and is smaller than that in the case of 4a) is.

In 4c) is a second galette 39 represented, which is convex. This is likewise pressed with the first predetermined force F against a further godet associated therewith, in particular with a complementary shape. This results in a width of the first fiber bundle 5 one that is smaller than in the case of 4a) ,

In 4b) is shown by means of the second galette 39 ' the second predetermined force, that is twice the first predetermined force F on the first fiber bundle 5 is exercised. This assumes a width that is greater than in the case of 4c) ,

Overall, it turns out that with the help of the device and the method in a simple and at the same time highly flexible, requirement-oriented, band-shaped semi-finished products 15 can be produced with asymmetric distribution of reinforcing fibers.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• WO 2013/086258 A1 [0002]

Claims (10)

Method for producing a band-shaped semifinished product ( 15 ) comprising reinforcing fibers and matrix material in asymmetric distribution, comprising the following steps: arranging at least two fiber bundles ( 5 . 7 . 9 ) over each other so that each fiber bundle ( 5 . 7 . 9 ) forms a layer, wherein - at least a first layer of matrix fibers and at least a second layer consists of reinforcing fibers, and - bonding the layers together to form a ribbon-shaped semifinished product ( 15 ). A method according to claim 1, characterized in that the layers are joined together by a sizing. Method according to one of the preceding claims, characterized in that the band-shaped semi-finished product ( 15 ) is processed without consolidation, partially consolidated or fully consolidated. Method according to one of the preceding claims, characterized in that at least three layers are formed, wherein - at least two outer layers of matrix fibers, wherein at least one inner layer consists of reinforcing fibers, or wherein - at least two outer layers of reinforcing fibers, wherein at least one internal layer consists of matrix fibers, or wherein - a multilayer, alternating sequence of layers of matrix fibers and reinforcing fibers is formed. Method according to one of the preceding claims, characterized in that the band-shaped semi-finished product ( 15 ) is wound, braided or laid. Method according to one of the preceding claims, characterized in that matrix fibers are used with embedded nanoferrites, the nanoferrites are encouraged to consolidate the band-shaped semi-finished product. Contraption ( 1 ) for producing a band-shaped semi-finished product ( 15 ), which comprises reinforcing fibers and matrix material in asymmetric distribution, with - an unwinding device ( 3 ) arranged for processing at least one matrix fiber bundle and at least one reinforcing fiber bundle, - a laying device ( 11 ) arranged for arranging the fiber bundles ( 5 . 7 . 9 ) in layers one above the other, and with - a pultrusion device ( 13 ), arranged for at least partially melting the matrix fibers. Contraption ( 1 ) according to claim 7, characterized by a spreading device ( 27 ) arranged to set a width of the fiber bundles ( 5 . 7 . 9 ). Contraption ( 1 ) according to one of claims 7 and 8, characterized by a splicing device ( 23 ) arranged for separating and connecting fiber bundles ( 5 . 7 . 9 ). Contraption ( 1 ) according to one of claims 7 to 9, characterized in that the pultrusion device ( 13 ) has a heating device which has a microwave source and / or an induction device.

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