EP2138615A1 - Method for producing a multi-axial fibre clutch, unidirectional fibre layers and method for its production, multi-axial fibre clutch and composite part with a matrix - Google Patents

Abstract

The method for producing a multi-axial wire structure in the form of an endless web, which is present in a transport device and moves itself with the transport device in its longitudinal direction, comprises broadening the fibers in an expanding process before displacing to unidirectional fiber layers, where each fiber is deformed to a strip, whose weight per unit area is highly 300 g/m 2>, and consecutively placing the unidirectional fiber layers with their fibers in the form of individual segments (5) in alternating longitudinal direction by using a laying device. The method for producing a multi-axial wire structure in the form of an endless web, which is present in a transport device and moves itself with the transport device in its longitudinal direction, comprises broadening the fibers in an expanding process before displacing to unidirectional fiber layers, where each fiber is deformed to a strip, whose weight per unit area is highly 300 g/m 2>, consecutively placing the unidirectional fiber layers with their fibers in the form of individual segments (5), which lie next to each other and consist of strips (3a, 3b), in alternating longitudinal direction by using a laying device, and temporarily fixing the unidirectional fiber layers at the transport device, where the longitudinal direction of the strips and the segments runs at an angle to the longitudinal direction of the resulting web-like wire structure. The raw material of the unidirectional fiber layers are made of fibers consisting of filaments, where the fibers are provided with a size. A transverse coherence is given to the individual strips in a manner before joining to the segments. The strips that closely lie next to each other remain within the segment in an unbondable manner. The segments pass through the entire placing process in an unbondable condition of the strip in the segment. Coherence takes place between the strips and between the segments of the different unidirectional fiber layers by temporarily fixing at the transport device. During placing process, a gripper (6) of the laying device pulls the strips over the transport device transverse to the formation of the segments. An equalization of different mechanical longitudinal stresses between the individual strips takes place in co-operation between the traction force of the gripper and the restoring force of the strips. The adhesion effect of the size between the filaments of the fibers and/or strips is reduced by targeted effect on the fibers and/or strips. The already broadened fibers are provided as finished intermediate product on disk coils, are removed by a wrap creel and are led to the gripper. A defined slippage of the strips is provided in the gripper and the ends of the segments turned away to the gripper are fixed into a clamping device (8) during the equalization of the different mechanical longitudinal stresses of all strips. The already expanded fibers of the finished intermediate product are provided on a common coil body of the disk coils, on which two already expanded fibers are winded next to each other. The broadening of the fibers takes place in a multi-axial machine for the production of the multi-axial wire structure. The fibers removed by the wrap creel pass through a stationarily arranged spreading unit and are led into the gripper in the form of broadened strips. All strips are fixed into the gripper during the equalization of the different mechanical longitudinal stresses and the restoring force of the strip is introduced by the coils of the wrap creel and to the spreading unit. The wrap creel is controllably moved together with the spreading unit as a common structural unit in a way, where the distance (L) is targetedly changed between the common structural unit and the laying device. The movement of the structural unit takes place at the strips in accordance with the requirement of the laying device varying in the unit of time, so that the fibers pass through the spreading unit with constant speed. The ends of the segments are fixed into the gripper for the equalization of the different mechanical longitudinal stresses of the individual strips. The segments are placed next to each other in a gas-free manner or are placed with an overlap or with a distance to each other. The targeted effects are mechanically, thermally or chemically carried out before, during or after the spreading. A cohesion medium is introduced before placing the segments on the fiber layers, is thermally activated after placing the segments and binds the fiber layers with one another. The adjacent strips are placed in a gas-free manner, placed with the overlap or placed spatially apart from each other. The transport device is a movable carrier, which is textile layer of the wire structure. After placing all the unidirectional fiber layers, the multi-axial wire structure is supplied to a connecting station, in which all fiber layers are sutured with one another, knitted or calendared. The transport device consists of conveyor chains, which shortly and slightly diverge transverse to its transport direction before fixing the layers. Each of the fibers is separately spreaded. The fibers are guided in different levels during spreading, so that all fibers freely lie in a lateral manner. The fibers of the unidirectional fiber layers consist of discontinuous filaments. The material of the fibers is carbon, ceramic, glass and/or aramide or consists of pre-products or intermediate products. The number of filaments is 12K. Independent claims are included for: (1) an unidirectional fiber layer; (2) a method for producing an unidirectional fiber layer; (3) a coil body; (4) a multi-axial wire structure; and (5) composite part.

Description

The invention relates to methods for producing a multiaxial yarn layer according to the preambles of claims 1 and 4. Both methods of this kind are known from the EP 0 972 102 B1 known. The multiaxial fabric scrims to be produced by the process are used primarily for the production of fiber-reinforced parts made of plastic, wherein the scrim is embedded in a matrix of a plastic.

In this application, the term "fiber" is used synonymously with cable, filament, filament cable or roving. In each case, a single fiber or thread is meant, which consists of a plurality of individual filaments and as a starting material has a cross-section of approximately circular or polygonal shape, but may also already have a flattened cross section in the manner of a rectangle with rounded corners , When such fibers are required in the form of very thin layers or plies, they are made for cost reasons by widening or spreading thick cables, each consisting of 12,000 (K number 12) or much more filaments.

According to the EP 0 972 102 B1 the fibers of the starting material are withdrawn from supply spools, widened in a Spreizaggregat and placed next to each other in the form of the resulting flat strips, so that a thin, flat layer is formed, which has a width of at least 5 cm and a basis weight of at most equal to 300 g / m ² should have. This layer is used as unidirectional layer for the construction of the multi-axial thread layer, wherein several unidirectional fiber layers are stored with changing directions on top of each other.

For better handling it is prescribed that the resulting unidirectional layers by an additional measure, a transverse cohesion is awarded, which extends over the entire width of this layer and thus on all bands from which this layer is formed. The bands are thus held together by the transverse cohesion. The measures for providing the transverse cohesion are known; Matting by a jet of pressurized water, the needles, the application of a chemical binder or the application of a thermo-fusible thread laid transversely over the unidirectional layer. The methods mentioned influence the desirable planar and smooth formation of the unidirectional layers. This can have a disturbing effect on the formed multiaxial netting which, in view of the later loading in a fiber-reinforced component, should have as homogeneous a texture as possible and a smooth surface on the outside.

According to the EP 0 972 102 B1 For example, the unidirectional sheets formed from the starting material and provided with cross-cohesion are first wound up on supply reels, which are later brought to the multiaxial machines for the construction of the multiaxial scrim. There, the layers are removed from the supply spools and brought over a transport device, where they are stored by means of a special installation device in individual cut segments on the transport device or an already existing unidirectional layer. To store the transport device can be stopped so that it can only be operated intermittently. The EP 0 972 102 B1 But also already describes a way to store the segments in continuously moving transport device. Here, the cut segments are temporarily fixed by means of pliers to a carrier which moves a short distance far above the transport device and in the direction thereof, wherein the respective held segment is transferred from the carrier to the transport device. There is also the term "Leger clamping device" for this purpose. Since according to the EP 0 972 102 B1 the individual bands within the segments are interconnected by the transverse cohesion, it is not possible to compensate for any difference in the length or the mechanical stress of the individual bands with each other. The quality of the resulting Multiaxialgeleges can be affected.

A comparable procedure is also from the FR-A-2180606 known. After that, construction parts from aviation technology and aerospace are to be produced with a smooth surface and low weight; Examples include propeller blades and turbine blades. The starting material is carbon fibers with a K number of 10 and more, which are widened by calibration to a basis weight between 90.4 and 123 g / m ² . The thickness of the resulting bands is given as 0.09 to 0.17 mm, and up to 282 of these bands should be arranged side by side. A simple recalculation shows that layers with a width of the order of 1000 mm are formed. Here, too, several of these layers are to be arranged one above the other in alternating directions to build up a multiaxial yarn layer, which then enters as reinforcement in a fiber-reinforced composite component such as a propeller blade.

In the FR-A-2180606 it is stipulated that the fibers of the starting material are provided with a size (matière d'encollage) for better processing. This is now a matter of course, because the common fibers of the starting material, so especially carbon fibers are made and sold at all only with the order of a size. A sizing not only wraps the fiber from the outside, but also penetrates into the interior of the fiber, makes the filaments smoother and holds the fiber together by adhesion, which facilitates textile processing. A sizing also protects the fiber against corrosion and abrasion, improves the adhesion to the matrix and protects against mechanical damage.

Incidentally, according to the FR-A-2180606 the widened bands placed next to one another are given transverse cohesion by means of a special measure, ie they are connected to one another. For this purpose, it is proposed to apply heat-fusible threads to the bands at regular intervals transversely to the longitudinal direction of the bands, which indeed hold the bands together but are not intended to pass through them. Also in this case, a cross-connection thus takes place with a material application and mutual fixing of the bands. This contradicts the requirement for a smooth surface and leads to the fact that length and tension differences between the individual adjacent bands can form.

In the two aforementioned known methods, a widened band is first produced by spreading the fibers of the starting material, which is stored as an intermediate to several bands next to each other or as a single band on supply reels. This semi-finished product is then brought to the multi-axial machine and withdrawn there again and stored in the form of segments to unidirectional thread layers. In operating jargon, such a procedure is referred to as "offline spreading". In contrast, the so-called "online spreading" is already known, in which the spreading unit is located directly next to the multi-axial machine and works in time with the laying device.

From the DE 10 2005 008 705 B3 is an apparatus for feeding slivers to a knitting machine out, in which the fibers of the starting material on their way from a creel to the laying device, ie in the "online process" widened. The fibers of the starting material already have the form of ribbons and are further widened in the device. For this purpose, the slivers of the starting material are individually withdrawn from spools and performed on the way from the creel to the band-laying device at a distance from each other and gradually widened by means of heating and pressure rollers. At the output of the device, a heating channel is arranged with the final spreading unit.

This heating channel is preceded by a tape storage. The band-laying device for storing the unidirectional layers is in the DE 10 2005 008 705 B3 not treated further. The intermittent and periodically fluctuating decrease of the spread bands by the band-laying device is compensated by the band-memory controlled in time with the band-laying device. As a result, at least on their way from the spool of the creel to the tape storage, the slivers can be withdrawn from the spools at a constant speed. In the heating channel with the final spreading unit, however, the belt speed must constantly change in accordance with the operation of the band-laying device, and it also phases of stoppage are required. This requires, inter alia, an adjustment of the heating power in the heating channel and is contrary to the requirement for a uniform as possible installation.

Finally, the older, not previously published European patent application concerns the applicant with the number 07 011 718.9 a method for applying a unidirectional fiber layer as well as a corresponding device and a multi-axial machine in which the creel is moved together with the Spreizaggregat as a common structural unit controlled in such a way that the distance between the common structural unit and the laying device is selectively changed ; In this case, the movement of the common structural unit takes place in accordance with the changing in the unit time requirement of the laying device on fiber share. With this older proposal it is achieved that the fibers of the starting material are not only withdrawn from the supply spools at a constant speed, but also pass through the spreader unit at a constant speed, which then also applies to the widened belts. Details of this older proposal are in the embodiment of this application on the basis of FIGS. 7 to 9 explained. The proposal according to the application 07 011 718.9 is a further contribution to the ever-present goal of laying the unidirectional fiber layers as evenly as possible and thus to create a multi-axial filament fabric with a homogeneous structure.

The invention is also based on the object that in the method according to the preambles of claims 1 and 4, the unidirectional fiber layers are stored evenly.

The first solution of this object is achieved with the entirety of the features of claim 1; the second solution is indicated by the entirety of the features of claim 4.

The first solution of the problem is based on the surprising finding that it is not necessary to give the fiber layer formed from the individual ribbons a transverse cohesion, which extends in summary over the entire layer width and also connects the individual bands together. With the techniques now available for the formation of the segments and their laying, it is possible to lay the bands even in the side unconnected state parallel to each other lying evenly. In addition, however, achieved by the embodiment according to claim 1 that differences in length and in the mechanical longitudinal stress between the individual bands can be compensated during the installation. There is also no difficulty in giving the widened ribbons a transverse cohesion that extends only across the width of a single ribbon. For this purpose, only a separate tape guide is required, for example, a tape guide in several levels or floors, with adjacent bands are laterally spaced from each other and thus are exposed laterally.

It is then sufficient that a cohesion between the bands of an unidirectional fiber layer and between the segments of the various unidirectional fiber layers by the usual temporary fixing takes place at the transport device.

The solution according to claim 4 is based on the recognition that the fibers which are important in practice, especially the carbon fibers, are only available in a commercial form in which they are provided with a size or another adhesive. The effect of the size can be reduced by targeted action. So it is e.g. It is known to lower the adhesion between the filaments of a fiber by heating, thereby reducing the effect of the size. By targeted action on the size and a suitable guidance of the fibers in the spread area is achieved according to the second invention proposal, that although the broadening of the fibers is made into bands and stabilized, but that adjacent bands remain essentially unconnected laterally. By the bands in this state undergo the entire laying process, a compensation of different mechanical longitudinal stresses is possible in cooperation between the tensile force of the gripper of the laying device with the restoring force of the bands. It is also sufficient in this case that the cohesion between the bands and segments within the unidirectional position is effected by the temporary fixing to the transport device.

The complete absence of measures to achieve a transverse cohesion in the procedure according to claim 4 brings the particular advantage that the flat and smooth arrangement of the unidirectional fiber layer is not disturbed and that no distortions or different mechanical longitudinal stresses between the individual bands are to be feared How easily occurs, if, for example, according to the prior art, heat-meltable Threads are applied at regular intervals transversely to the longitudinal direction of the adjacent bands.

Further developments of the methods according to the invention are specified in claims 2, 3 and 5 to 22.

In this case, the claims 5 to 8 relate to the assignment of the spreading process to the inventive method. These can be carried out in the method of offline spreading, but also of online spreading. In offline spreading according to claim 5, the gripper must be operated with a defined slip of the bands, and the restoring force of the bands in the compensation of the different mechanical longitudinal stresses is applied by a clamping device, which is already present in the laying device. The coils should be designed as disc coils. It is particularly advantageous if the already spread as an intermediate product bands are provided on at least one common bobbin a disc coil, with several spread bands are wound side by side, but have no connection with each other, so are unconnected.

If the method is operated according to the principle of online spreading, cf. claims 7 and 8, the fibers of the starting material may be present on cheeses or on disc coils in the creel. In the arrangement on disc coils only one fiber should be wound on each disc coil. In this case, the gripper must grasp the adjacent belts firmly, ie without any slippage, and guide them over the transport device. The restoring force of the bands comes about in these cases by the coils of the creel and also by the spreader. Dienlich here is that the coils are usually equipped with drain brakes anyway. By the gripper without any slip pulls the bands of the resulting segment against the restoring force of the coil and Spreizaggregat on the transport device, a compensation of the mechanical longitudinal stresses between the individual bands is performed in this case.

What has been said about claims 7 and 8 applies to online spreading with stationary or together with the creel moved spreading unit. However, there is a peculiarity in the case of claim 8, when the common structural unit of creel and Spreizaggregat performs their return movement, ie during the installation process. In this case, the already mentioned clamping device holds the supply ends of the bands to the laying device. The clamping device now effectively replaces the gripper, and in this way comes again a compensation of the mechanical longitudinal stresses by the pulling action of the common structural unit of spreader and creel realized.

The method according to the online spreading according to claim 8, wherein the creel is moved together with the spreading unit as a common unit according to the changing in the unit time needs of the laying device to tapes back and forth, is particularly advantageous because then the fibers of the starting material the Go through the spreading unit at a constant speed. The procedure according to the earlier European patent application 07 011 718.9 is thus adopted as training in the method according to claim 8 of the present application.

Particularly noteworthy are further the different ways to act in accordance with claims 10 and 11 in a targeted manner to the provided with a sizing fibers and / or bands. The targeted action can be carried out before, during or after spreading, wherein the method is performed so that the spreading process is successfully carried out and stabilized, while an adhesion effect is laterally avoided between the individual bands. The targeted action may be mechanical, e.g. By rolling a lateral vibration is applied to the bands. A thermal action takes place by heating, but also a chemical treatment or an activating irradiation is possible.

Particularly advantageous is the possibility according to claim 12 that before depositing the segments on one of the fiber layers, a cohesive is applied, which initially remains latent, but is thermally activated after the laying of the segments and the deposited fiber layers together. The cohesion agent may e.g. be applied in the form of a powder before laying on the bevy of bands that together form a segment. Likewise, such a powder can also be applied to an unidirectional layer already laid down on the transport device in order to connect the next unidirectional layer to be applied as soon as the cohesive effect of the cohesive agent is activated.

Activation can take place after all unidirectional fiber layers have been deposited, ie the multiaxial fabric is finished. The cohesion agent can also be activated occasionally during the laying process, if there is a risk that the support of the superimposed unidirectional layers on the transport device is not sufficient and thus the uniform storage is at risk.

The invention also relates to an undirectional fiber layer according to claim 23, which is useful in carrying out the method according to claim 1. Further developments of this unidirectional fiber layer are specified in claims 24 to 27. Claim 28 then sets forth a method of making such a unidirectional fiber sheet as an intermediate by winding a number of ribbons side by side on a disk bobbin, the bands each having transverse cohesion but being unconnected laterally.

Claims 29 and 30 relate to the corresponding unidirectional fiber layer which is useful in carrying out the method according to claim 4 and the corresponding method for producing this unidirectional fiber layer as an intermediate.

Also used as an intermediate product is a bobbin having a unidirectional fiber layer according to claim 31, while claims 32 to 35 relate to a multiaxial netting as can be made according to claim 1, optionally with one or more further developments according to the subclaims directed thereon.

Finally, claim 36 is directed to a composite part, i. directed to a fiber-reinforced component, which is produced by a method according to any one of claims 1 to 20.

• Fig. 1 zeigt schematisch in zwei Teildarstellungen 1a und 1 b, wie beim Spreizen einer Faser die Filamente in die flache Form des Bandes übergehen.
• Fig. 2 stellt in stark vereinfachter Form drei unterschiedliche Phasen beim Zusammenwirken der Schlichte mit zwei Filamenten innerhalb einer Faser beim Spreizen dar.
• Fig. 3 ist eine Prinzipdarstellung und verdeutlicht in zwei Teildarstellungen gemäß den Fig. 3a und 3b anhand einer ersten Ausführungsform, wie dank des erfindungsgemäßen Verfahrens bei der Ablage einer unidirektionalen Faserlage unterschiedliche mechanische Spannungen und Längen zwischen den Bändern eines abzulegenden Segments ausgeglichen werden können.
• Fig. 4 erläutert die Vorteile des erfindungsgemäßen Verfahrens an einer zweiten Ausführungsform.
• Fig. 5 zeigt eine Möglichkeit, wie im Zuge der Verbreiterung den einzelnen Bändern eine Querkohäsion erteilt werden kann, ohne dass Querkohäsion zwischen den Bändern zustande kommt.
• Fig. 6 zeigt verschiedene Möglichkeiten, wie die Station zur Einwirkung auf die Fasern und/oder Bänder angeordnet sein kann, wenn Maßnahmen zum Aufbringen von Querkohäsion nicht beabsichtigt sind.
• Figur 7 ist die Seitenansicht einer Multiaxialmaschine, bei der Spulengatter und Spreizaggregat auf einem gemeinsamen Laufwagen angeordnet sind.
• Figur 8 zeigt eine Ansicht von oben auf das Innere des Laufwagens gemäß Figur 7.
• Figur 9 verdeutlicht im Sinne einer Prinzipskizze das Zusammenwirken aller Funktionsteile der Multiaxialmaschine gemäß den Figuren 7 und 8.
• Figur 10 zeit die Verwendung einzelner Kreuzspulen für das Ausgangsmaterial und einer Scheibenspule mit mehreren Bändern, die seitlich unverbunden sind, als Vorrat für die Segmente.

The invention will be explained in more detail with reference to schematically illustrated embodiments. In the figures, the following is shown:

• Fig. 1 shows schematically in two partial representations 1a and 1b, as when spreading a fiber, the filaments in the flat shape of the band pass.
• Fig. 2 represents in a greatly simplified form three different phases in the interaction of the sizing with two filaments within a fiber during spreading.
• Fig. 3 is a schematic diagram and illustrates in two partial representations according to the Fig. 3a and 3b Based on a first embodiment, how can be compensated for by the inventive method in the storage of a unidirectional fiber layer different mechanical stresses and lengths between the bands of a segment to be deposited.
• Fig. 4 explains the advantages of the method according to the invention in a second embodiment.
• Fig. 5 shows a possibility, how in the course of widening the individual tapes can be given a transverse cohesion without cross cohesion between the tapes.
• Fig. 6 Figure 4 shows various ways in which the station can be arranged to act on the fibers and / or bands, if measures for applying cross-cohesion are not intended.
• FIG. 7 is the side view of a multi-axial machine, are arranged in the creel and spreading unit on a common carriage.
• FIG. 8 shows a view from above of the interior of the carriage according to FIG. 7 ,
• FIG. 9 illustrates in the sense of a schematic diagram the interaction of all functional parts of the multi-axial machine according to the FIGS. 7 and 8 ,
• FIG. 10 the use of individual source packages and a disc coil with multiple tapes unconnected laterally as a supply to the segments.

In Fig. 1 is shown in the partial view a very schematically a cross section through a single fiber 1, which may be a carbon fiber. The fiber, for which the term thread, cable or filament cable is customary, is composed of a large number of filaments 2. The range of interest here may be carbon fibers 1 with K numbers of 12 to 50 and more, ie carbon fibers of 12000 to 50,000 filaments 2 and more. For economic reasons, thin unidirectional yarn layers are produced by drawing the fibers 1 as a starting material according to the partial illustration a and broadening them into spreading devices. The fibers of the starting material need not have a cross section in the form of a polygon or approximately circular cross section, as shown here. Also common is the commercial form of sliver, which already has a flattened cross-section of approximately rectangular shape, but for practical applications is still much too thick, so also has to be broadened.

It is desirable to have a widening in which a grammage of the widened band 3 and the unidirectional layer formed thereby is set to 300 g / m ² and less. Ideally, such a broadened fiber 1 would have a cross-section, as in the section in the partial view b of Fig. 1 is shown. The thickness of the band 3 would be about the

Diameter of a single filament 2 correspond. In practice, it comes at most to an approximation to this condition.

In the process of broadening the behavior of the size 4 is important. The common fibers 1 of the starting material, so especially carbon fibers are produced and sold only with the order of a size. As Fig. 1 4, the sizing 4 not only envelopes the fiber 1 from the outside, but also penetrates into the interior of the fiber 1, makes the filaments 2 smoother and holds the fiber 1 together by adhesion, which facilitates textile processing. The size 4 also protects against corrosion and abrasion, improves the adhesion to the matrix and protects against mechanical damage.

The adhesion effect of the size 4 is hindering the spreading of the fibers 1 of the starting material. Through targeted thermal, mechanical or chemical action on the fibers 1 and / or bands 3, the effect of the size 4 and thus the adhesion between the filaments 2 can be weakened, whereby spreading is facilitated and the spread state is stabilized. The thermal weakening of the adhesion is particularly well known in that the fibers are transported through a heating device in which the sizing also heats up and partially or completely loses its effect. Mechanical action may be to vibrate the fibers transversely. Finally, the chemical action is possible by a diluent or solvent in a certain concentration acts on the fibers and thus also on the sizing. In Fig. 2 the conditions are shown schematically.

Between two filaments 2 there is a membrane-like compound through the size 4, which is first stretched when widening the fiber 1, cf. Fig. 2a , In the illustration according to Fig. 2b the connecting sizing 4 is already overstretched; it can be seen that the widened band 3 has the tendency to return elastically at least partially to the initial state. According to Fig. 3b the connecting sizing 4 is broken; So there is no connection between the filaments. 2

By weakening, for example, by heating the influence of the size 4 on the adhesion between the filaments 2, intermediate states can be set in which a continuous broadening of the cable 1 is achieved, but otherwise the advantageous effect of the size 4 is retained as far as possible.

The advantageous for the spreading process reduction of the adhesion between the filaments 2 also affects the behavior of the bands 3, which is a segment 5 (see. Fig. 3 ) next to each other placed and stored to build a unidirectional position. Namely, between the adjacent bands 3 is no longer adhesion, if the effect of the size 4 has been reduced. The bands of a segment thus have no connection with each other. According to the method of the invention, this supposed disadvantage is transformed into an advantage in that the bands 3 remain unconnected in the segment 5 and in this state undergo the deposition process. This procedure has the advantage that differences in the mechanical longitudinal stress, which inevitably exist between the individual bands of a segment 5, can be compensated shortly before the final transfer of the segment 5 to the laying device of the laying device.

In Fig. 3 the conditions are shown in a first embodiment. It is assumed that the already widened bands 3a, 3b are obtained from a supplier and brought as an intermediate product to the location of the multi-axial machine. In business jargon, this is called "offline spreading". The bands 3a, 3b are already formed by the method according to the invention by being laterally without significant adhesion or cohesion effect, so remain unconnected when juxtaposed. The bands 3a, 3b can each be deducted from disk coils of a creel and brought together until they are parallel to each other. According to FIG. 3 However, the bands 3a, 3b are provided on a common bobbin of a disc coil 12, wherein the bands 3a, 3b are unconnected laterally. The representation of such a disk coil 12 in concrete form shows FIG. 10 , where cheeses 17 are shown there for the starting material. The respective front end of this parallel fiber bundle is pulled by a gripper 6 across the transport unit, transferred to the Leger clamping device, separated from the remaining parallel fiber bundle and finally attached to the transport device. This type of laying can be done with intermittent or continuously moving transport device.

Fig. 3 shows only the parts needed to understand the principle. With 6 of the gripper is designated, which pulls the consisting of two bands 3a, 3b segment 5 across the transport device, not shown, which extends below the segment 5 and consists for example of two conveyor chains. The pulling direction is indicated by the directional arrow 7. A clamping device 8 serves to hold the segment 5 until it is separated by means of the separator 9 from the parallel fiber bundle supplied. Thus, the single segment 5 is present as an independent part and is stored by a Leger clamping device 16 on the transport device, not shown.

The FIGS. 3a and 3b show the state of the segment 5 just before its laying by the Leger clamping device. According to Fig. 3a the segment 5 is not stored homogeneously; because the upwardly facing bulge 10 on the upper band 3a in the illustration indicates a difference in length and thus a different mechanical longitudinal stress in the segment 5. According to the method of the invention, the tapes 3a and 3b are not connected laterally because adhesion is not present and no measures are taken to achieve transverse cohesion between the tapes 3a and 3b.

Furthermore, despite sufficient tensile force, the gripper 6 allows slippage of the bands 3a and 3b during the pulling movement. Through specific material selection in the parts of the gripper 6 that grip the bands 3a, 3b, it is possible to achieve that the gripper 6, on the one hand, transmits a sufficient tensile force, but, on the other hand, allows a slippage movement of the bands 3a, 3b in the gripper 6 in a targeted manner. A compensating movement already comes about when the gripper 6 pulls the front ends of the bands 3a, 3b, which form the segment 5, across the transport means. The decisive factor, however, is that the gripper 6 at the conclusion of its installation movement, when the clamping device 8 is closed, once again performs a brief tensioning movement and thereby unifies the mechanical longitudinal stress of the bands 3a, 3b. This may be a very short movement in the millimeter range, which the gripper 6 performs once again with respect to the clamping device 8 at the cutting end of the segment 5. Immediately thereafter, the segment is transferred to the Leger clamping device.

The tighter tensioned band 3b thus slides last in the pulling movement in the gripper 6, while the slacker band 3a is pulled taut and last in the area between the gripper 6 and the clamping device 8 has the same mechanical longitudinal tension as the band 3b. This final state is in Fig. 3b shown, in which the change is also visible on the supernatant of the belt 3a against the belt 3b outside of the gripper 6.

The method according to the invention can also be carried out on multi-axial machines in which the fibers of the starting material are brought to the machine and widened on the machine itself. This procedure is also referred to in business jargon as "online spreading". Common are stationary arranged spreading units, which are located between the creel and the laying device. Although it is provided at the output of the creel, a compensation loop for the fibers, can not be prevented that the widened bands of the laying device are supplied with periodically changing running speed. For the possibility already described, to bring about a compensation of different mechanical longitudinal stresses between the individual bands of a segment when laying the segments, nothing changes.

The restoring force of the belts, which acts against the pulling force of the gripper, can not only be brought about in the case of on-line spreading, not only by the disk coils of the creel, but also by the spreading unit. This is all the more true, since the bands anyway do not pass through the stationarily arranged spreading units at a constant speed, insofar as there is no fundamentally new disadvantage due to the retroactive effect of the compensating movement. Under certain circumstances, the clamping device for the compensating movement, which is already present, can optionally also be used.

A further tightening and equalizing of the segments 5 can be carried out by a conveyor in the form of conveyor chains these diverge slightly at the inlet to the final connection station, including the located on the conveyor chains fasteners for the ends of the segments 5 also a slip of the bands 3a, 3b must allow. The prerequisite is in any case that the individual bands within a segment 5 and thus also the segments 5 are largely free of adhesion and free of cohesion, ie laterally unconnected and can move against each other. This also applies if each band 3a, 3b has transverse cohesion per se.

FIG. 4 is a schematic compilation that summarizes the details discussed so far and prepares the following illustrations. Denoted at 11 is a processing station in which all the facilities required for spreading and further treating the fibers and / or belts are summarized. The illustration shows a closed clamping device 8 and a gripper 6 in the end position. The voltage compensation is already done, with the required restoring force to the gripper 6 through the coil of the creel and / or a spreader is done.

In FIG. 5 is shown a way how the fibers 1 a, 1 b of the starting material initially widened together and then treated separately in pairs. The fibers 1a, 1b already have the starting shape of a relatively thick band and are therefore drawn off from disk coils 12. With a starting form of fibers which have approximately circular cross-section, cheeses are the standard solution. The fibers 1a, 1b are passed through the rollers 13 of a spreading unit and thereby undergo a widening to bands 3a, 3b. By means of guide rollers 14, the widened bands 3a, 3b are separated in pairs by further treating a first group 3a in a first higher level and a second group of bands 3b in a second, lower level. The bands 3a, 3b in each floor are also laterally spaced from each other. With 15 an influencing station is designated, with the targeted on the bands 3a of the upper floor is acted upon. A corresponding processing station 15 may also be provided for the bands 3b of the lower floor. The influence may be that the bands 3a, 3b are heated, whereby the effect of the size and the mutual adhesion of the filaments 2 in the bands 3a, 3b is reduced. In this way, the broadening of the fibers 1a, 1b to ribbons 3a, 3b achieved by the spreading is stabilized. In addition, the lateral adhesiveness of the bands is reduced, so that the bands 3a, 3b remain virtually unconnected when they are brought together again after passing through the last deflection roller 14. Similarly, the interference station 15 or a further adjunct station may serve to apply a transverse cohesive to each of the bands 3a, 3b separately. The type of tape guide causes also in this case, that after leaving the processing station 11, although each of the bands 3a, 3b additionally has a transverse cohesion, but that this transverse cohesion is not effective between the bands 3a, 3b.

Furthermore, in such an influencing station 15, a cohesive agent can be applied to the bands 3a, 3b, which initially remains latent but can be activated at a desired time when two unidirectional layers are deposited on one another. The activation can be done for example by heat or irradiation.

Depending on the type of fiber to be laid, it is not always necessary to treat the tapes 3a, 3b to specifically influence their adhesion behavior on different floors. FIG. 6 shows a process guide in the event that the targeted influence is effective even with adjacent bands 3a, 3b. If the effect of the sizing is so far weakened that the spreading effect is maintained and the adhesion between the filaments is reduced, so are also in this case before bands 3a, 3b, which can be shifted in the longitudinal direction to compensate for length and voltage differences against each other.

Moreover, in FIG. 6 schematically shown that the influencing station 15 in the running direction 7 of the bands 3a, 3b seen before, can be arranged exactly above or behind the rollers 13 of the Spreizaggregates. It is always important to enable the spreading process by targeted action on the fibers 1a, 1b and / or bands 3a, 3b at all, but also to maintain the spreading result and to achieve that the spread bands 3a, 3b remain unconnected, too if they are parallel next to each other.

The inventive method can be carried out with particular advantage in such multi-axial machines in which the spreading unit is not arranged stationary, but is moved together with the creel as a common structural unit controlled. The movement of this structural unit is carried out in accordance with the changing in unit time requirements of the laying device on tapes, in such a way that the fibers of the starting material are withdrawn at a constant speed of the bobbin creels and also go through the spreading unit at a constant speed. Such a multi-axial machine and its method are in the older, but not previously published European patent application of the applicant with the number 07 011 718.9 presented and described in detail. It can be referred in this respect to this earlier application.

For better understanding of the present application, but the most important details of the earlier application are described below with reference to the FIGS. 7 to 9 described. In contrast to the previous description with the FIGS. 1 to 6 the reference numbers begin in the FIGS. 7 to 9 with the number 21.

In FIG. 7 is denoted by the reference numeral 21, a machine frame, which can form a lateral attachment of a multi-axial machine, see. this the FIG. 9 , The machine frame 21 has a track in the form of guide rails 22. In this, the common structural unit in the form of a carriage 23 by means of rollers 24 is movable. The carriage 23 carries a creel 25 and a spreading unit 26, which is designed as a continuous unit. The creel 25 consists of a plurality of coils 27 on which individual fibers 28, for example carbon fibers or aramid fibers, are wound up as the coil material.

The individual fibers 28 are withdrawn via pulleys 29 of the coils 27 and guided by the spreading unit 26. For the arrangement of the coil 27 and the guide roller 29, it is crucial that the deducted individual fibers 28 do not touch each other before entering the Spreizaggregat 26. The coils 27 are equipped with braking devices to allow the tension in the stripped fibers 28 to be adjusted and controlled. The pulleys 29, as well as any existing guide eyelets or similar guide members must have a smooth surfaces so that they do not damage the sensitive coil material. In order to exclude mutual contact of the withdrawn fibers 28, the individual coils 27 and guide roller 29 are not only offset in height but also laterally, cf. the FIG. 8 , For the execution of the spreading unit 26 numerous proposals are known. For example, the fibers 28 may be widened by passing over rollers which vibrate or are heated in their axial direction. Also the treatment with rotating, curved rollers for the purpose of spreading or widening belongs to the prior art. The different methods can also be used together. The aim of this treatment is always to transform the thick individual fibers 28 of the starting material, especially carbon fibers, into flat bands 30 having a weight per unit area of at most 300 g / m ² , which lie parallel next to one another. In the FIGS. 8 and 9 the bands 30 are shown lying close together. However, it is also possible a different arrangement way, as the basis of the FIGS. 1 to 6 has already been executed.

In FIG. 9 It is shown how the arranged on a carriage 23 structural unit of creel 25 and spreading unit 26 of the multi-axial machine is spatially associated with and cooperates with this. Of the multi-axial machine only the two conventional conveyor chains 32a, b are indicated, the upper halves move in the transport device according to the directional arrows 38. An arrow 39 indicates the laying direction of the belts 30 provided on the carriage 23.

The fiber bundle 30 provided by the carriage 23 is transferred to the conveyor chains 32a, b by means of a laying device 33. Their function is to take over a portion of the warp provided on the carriage 23 of the bands 30, to lead over the conveyor chains 32a, b, separate from the endless supply and finally pass to the fastening devices, which on the conveyor chains 32a, b are located. As the FIG. 9 shows the machine frame 21 is arranged for the carriage 23 in the laying direction 39 of the bands 30 laterally adjacent to the multi-axial machine. In other words, the carriage 23 with the creel 25 and the spreading unit 26 moves back and forth in the direction of laying 39 of the belts 30 in a controlled manner.

In the DE 102 14 140 B1 The applicant is already described and illustrated a laying device with which a fiber bundle provided by an endless supply, transferred in cut-to-length sections via the conveyor chains 32a, b of a multi-axial machine and finally secured in clamping devices which are located on the conveyor chains. Such a laying device can also be considered for the broadened bands 30 assumed in the present application with a basis weight of at most 300 g / m ² .

The reference numeral 31 is in FIG. 9 denotes a releasable clamping device which serves as a holding and detecting means and the front free end of the spreading unit 26 leaving belts 30 holds until it is passed over the conveyor chains 32a, b. For this is a gripper 35, which is driven along a guide track 34 transversely to the conveying direction 38 of the conveyor chains 32a, b reciprocatingly movable. The guideway 34 therefore also runs in the laying direction 39 of the belts 30. When the clamping device 31 is released, the gripper 35 takes over the free ends of the belts 30 and guides them across the conveyor chains 32a, b. The band-shaped section of the fiber bundle 30 located above the two conveyor chains 32a, b is then separated from a separating device, not shown, which is located in the region of the clamping device 11, and thus becomes a separate segment 30a. The newly formed free ends of the still on the carriage located bands 30 are then held by the clamping device 31 again. By contrast, the cut-to-length segment 30a located above the conveyor chains 32a, b is gripped at its two ends by a laying device 36, which likewise belongs to the laying device 33, which is driven in the direction of the conveyor chains 32a, b to move back and forth. The leger clamping device 36 finally transfers the segment 30a to clamping devices, not shown, which are located on the conveyor chains 32a, b. The segment 30a has thus finally become part of the laid unidirectional fiber layer 37.

In FIG. 9 a movement phase is shown in which the clamping device 31 is closed and the gripper 35 has indeed already detected the free ends of the bands 30, but is still at rest. As a result, the carriage 23, the clamping device 31, the gripper 35 and the Leger clamping device 36 cooperate intermittently, the carriage 23 by the length L ( FIG. 9 ) is reciprocated in accordance with the movement of the gripper 35.

The compensation of differences in the longitudinal tension of the bands 30 also takes place in the multi-axial machine according to the FIGS. 7 to 9 in cooperation between the bobbins 27 of the creel 25, the spreading unit 26, the clamping device 31 and the gripper 35. When the gripper 35 performs its transport or laying stroke and a group of bands 30 across the conveyor chains 32a, 32b pulls, the restoring force the bands 30 applied by the coil 27 and the spreading unit 26. The gripper 35 must in this case, the bands 30 clamped firmly, so grab and pull without any slippage. When the front end of the group of bands 30 is severed and the carriage 23 moves back, the storage end of the bands 30 in the clamping device 31 is held slip-free. The carriage 23 exerts a pulling action on the newly arising stock end, wherein the required tensile force, which must act on the bands 30, comes about through the coils 27 and the spreading unit 26.

• die Fasern 28 des Ausgangsmaterials werden mit gleich bleibender Geschwindigkeit von den Spulen des Spulengatters 25 abgezogen;
• die Fasern 28 und Bänder 30 durchlaufen das Spreizaggregat 26 ebenfalls mit gleich bleibender Geschwindigkeit;
• im Zusammenwirken des Greifers 6, 35 mit der Rückstellkraft der Bänder 3, 3a, 3b, 30 kann ein Ausgleich von Spannungsunterschieden zwischen den einzelnen Bändern erfolgen, und
• (bei der Vorgehensweise nach Anspruch 4 der Anmeldung:) die ebene Anordnung und glatte Oberfläche der Segmente wird nicht durch von außen aufgeprägte Maßnahmen zur Bildung einer Querkohäsion gestört.

The result of the procedure according to FIGS. 7 to 9 is a very uniformly laid unidirectional layer 37. It is based on the following measures that the bands 30 combined into segments 30a are particularly flat and regular next to each other:

• the fibers 28 of the starting material are withdrawn at a constant speed from the spools of the creel 25;
• the fibers 28 and belts 30 also pass through the spreading unit 26 at a constant speed;
• in the interaction of the gripper 6, 35 with the restoring force of the bands 3, 3a, 3b, 30 can be done a balance of voltage differences between the individual bands, and
• (in the procedure of claim 4 of the application :) the planar arrangement and smooth surface of the segments is not disturbed by externally imprinted measures to form a transverse cohesion.

List of reference numbers FIGS. 1 to 6:

1, 1a, 1b

Fiber (starting material)

2

filament

3, 3a, b

Band (spread starting material)

4

plain

5

segment

6

grab

7

installation direction

8th

clamper

9

separator

10

bulge

11

processing station

12

pancake coils

13

Rolling of the spreading unit

14

deflection rollers

15

influencing station

16

Leger-clamping device

17

cheese

FIGS. 7 to 9:

21

Machine frame, side mounting

22

guide rails

23

common structural unit, carriage

24

castors

25

creel

26

Spreizaggregat

27

Kitchen sink

28

Fibers (starting material)

29

guide rollers

30

bands

30a

segment

31

Clamping device (holding and detecting device)

32a, b

conveyor chains

33

laying device

34

guideway

35

grab

36

Leger-clamping device

37

unidirectional location

38

Directional arrow for the conveying direction of the conveyor chains

39

Arrow for the laying direction of the bands

40

Motion arrow (gripper)

41

Movement arrow (Leger clamping device)

42

Motion arrow (carriage)

L

variable distance

Claims (36)

A method of making a multiaxial naps in the form of an endless web located on and moving in a longitudinal direction of a transport means, successively depositing unidirectional fiber layers of varying lengths along their fibers and temporarily fixed to the transport, with the following steps: a) the starting material of the unidirectional fiber layers are filament fibers which are provided with a size; b) before laying into a multiaxial netting, the fibers are widened in a spreading process, wherein each fiber is deformed into a ribbon whose basis weight is at most 300 g / m ² ; c) the unidirectional fiber layers are deposited in the form of juxtaposed individual segments, each of which consists of at least two bands, wherein the longitudinal direction of the bands and thus the segments extends at an angle to the longitudinal and direction of movement of the resulting web-shaped Fadengeleges;
characterized in that the following further method steps are provided: d) the individual tapes (3, 3a, 3b, 30) is given a transverse cohesion to the segments (5, 30a) prior to assembly in such a way that the adjacent bands (3, 3a, 3b, 30) within the segment (5, 30a) remain substantially unconnected; e) in this state, the segments (5, 30a) go through the entire deposition process, wherein a cohesion between the bands (3, 3a, 3b, 30) and between the segments (5, 30a) of the various unidirectional fiber layers by temporarily fixing the transport device takes place. A method according to claim 1, characterized in that during the depositing operation, a gripper (6, 35) pulls the belts (3, 3a, 3b, 30) across the transport device to form the segments (5, 30a), wherein in cooperation between the tensile force of the gripper (6, 35) and the restoring force of the bands (3, 3a, 3b, 30) a compensation of different mechanical longitudinal stresses between the individual bands (3, 3a, 3b, 30) takes place. A method according to claim 1 or 2, characterized in that when applying the transverse cohesion adjacent bands (3, 3a, 3b, 30) are laterally spaced from each other. A method of making a multiaxial plied fabric in the form of an endless web which is on a transport and moves therewith in its longitudinal direction, wherein a laying device successively deposits at least two unidirectional fiber layers with changing longitudinal direction of their fibers and these fiber layers temporarily on the transport device be fixed, with the following steps: a) the starting material of the unidirectional fiber layers are filament fibers which are provided with a size; b) before laying into a multiaxial netting, the fibers are widened in a spreading process, wherein each fiber is deformed into a ribbon whose basis weight is at most 300 g / m ² ; c) the unidirectional fiber layers are deposited in the form of juxtaposed individual segments, each of which consists of at least one band, wherein the longitudinal direction of the bands and thus the segments at an angle to the longitudinal direction of the resulting web-shaped Fadengeleges runs and a gripper of the laying device pulling the bands across the transport means to form the segments; characterized,
in that the adhesion action of the sizing (4) between the filaments (2) of the fibers (1. 1a, 1b, 28) and / or tapes (3, 3a, 3b, 30) before being laid is determined by acting on the fibers (1 , 1 a, 1 b, 28) and / or bands (3, 3a, 3b, 30) is reduced and the process is carried out in such a way that also closely adjacent bands (3, 3a, 3b, 30) remain substantially unconnected, and that the bands (3, 3a, 3b, 30) in this state undergo the entire laying operation, wherein in cooperation between the tensile force of the gripper (5, 30a) and the restoring force of the bands (3, 3a, 3b, 30) a compensation different longitudinal mechanical stresses between the individual bands (3, 3a, 3b, 30) takes place and the cohesion between the bands (3, 3a, 3b, 30) and segments (5, 30a) within the unidirectional position by the temporary fixing to the transport device he follows. Method according to one of claims 1 to 4, characterized in that the already spread belts (3a, 3b) are provided as finished intermediate on disc spools (12), withdrawn from a creel and fed to the gripper (6) a defined slip of the bands (3a, 3b) in the gripper (6) is provided and in balancing the different mechanical longitudinal stresses all bands (3a, 3b) on the gripper (6) facing away from the end of the segment (5) in a clamping device (8 ) are fixed. A method according to claim 5, characterized in that the already spread bands (3a, 3b) of the intermediate product are provided on at least one common bobbin of a disc coil (12) on which at least two spread bands (3a, 3b) are wound side by side but unconnected , Method according to one of claims 1 to 4, characterized in that the widening of the fibers (3a, 3b) takes place at the Multiaxialmaschine for producing the multi-axial Fadengeleges, wherein the withdrawn from a creel fibers (1, 1 a, 1 b) of the starting material pass through a stationary arranged spreading unit and in the form of widened bands (3a, 3b) are fed to the gripper (6), wherein the balancing of the different mechanical longitudinal stresses all bands (3a, 3b) are fixed in the gripper (6) and the restoring force the bands (3a, 3b) is applied by the coils of the creel and the spreader. Method according to one of claims 1 to 4, characterized in that the following method steps are provided: a) the widening of the fibers (28) takes place on the multiaxial machine for producing the multiaxial yarn layer, the fibers (28) drawn off from a creel (25) passing through a spreading unit (26); b) the creel (25) is moved together with the Spreizaggregat (26) as a common structural unit (23) controlled in such a way that the distance L between the common structural unit (23) and the laying device (33) is selectively changed ; c) the movement of the common structural unit (23) takes place in accordance with the requirement of the laying device on belts (30) that changes in unit time such that the fibers (28) of the starting material pass through the spreading unit (26) at constant speed, d) to compensate for different mechanical longitudinal stresses between the individual bands (30) of a segment (30 a) whose ends are fixed in the gripper (35), and the restoring force of the bands (30) of the coils (27) of the creel (25) and the spreading unit (26) applied. Method according to one of claims 1 to 8, characterized in that the segments (5, 30a) are stored off-gas side by side or with an overlap or with a distance to each other. Method according to one of claims 4 to 9, characterized in that the targeted action before, during or after the spreading is carried out. A method according to claim 10, characterized in that the targeted action is carried out mechanically, thermally or chemically. Method according to one of claims 1 to 11, characterized in that before depositing the segments (5, 30a) on one of the fiber layers, a cohesive is applied, which is thermally activated after the laying of the segments (5, 30a) and the fiber layers together combines. Method according to one of claims 1 to 12, characterized in that adjacent bands are stored without a gap, with overlapping or spaced from each other. Method according to one of claims 1 to 13, characterized in that the transport device is a moving carrier. A method according to claim 14, characterized in that the carrier is a textile layer of the multiaxial yarn layer itself. Method according to one of claims 1 to 15, characterized in that after filing all unidirectional fiber layers, the multiaxial scrim is fed to a connection station in which all fiber layers are sewn together, forfeited or calendered. A method according to claim 12, characterized in that the transport device consists of transport chains, which diverge slightly shortly before the fixing of the layers transversely to its transport direction. Method according to one of claims 1 to 17, characterized in that each fiber (1, 1 a, 1 b, 28) is spread separately. A method according to claim 18, characterized in that the fibers (1, 1a, 1 b, 28) are guided during spreading in different planes, so that all the fibers (1, 1a, 1 b, 28) are exposed laterally. Method according to one of claims 1 to 19, characterized in that the fibers (1, 1a, 1 b, 28) consist of at least one unidirectional fiber layer of discontinuous filaments. Method according to one of claims 1 to 20, characterized in that the material of the fibers (1, 1a, 1 b, 30 a) carbon, ceramic, glass, aramid, a mixture thereof or consists of their precursors or intermediates. Method according to one of claims 1 to 21, wherein the filament number of the fibers (1, 1a, 1 b, 30 a) is at least 12K. Unidirectional fiber layer having a basis weight of at most 300 g / m ² , consisting of a layer of parallel juxtaposed tapes, which are formed by widening fibers, which in turn consist of a plurality of continuous or discontinuous filaments and are provided as a starting material with a sizing , characterized in that each individual band (3, 3a, 3b, 30) is provided with a means for achieving a transverse cohesion, but that the adjacent bands (3, 3a, 3b, 30) are substantially unconnected. Unidirectional fiber layer according to claim 23, characterized in that the transverse cohesive agent is an adhesive which is applied before depositing the unidirectional layer and is activated after deposition. Unidirectional fiber layer according to Claim 24, characterized in that the transverse cohesive is a heat activatable agent. Unidirectional fiber layer according to claim 23, characterized in that the transverse cohesive is a chemical binder. Unidirectional fiber layer according to claim 23, characterized in that the transverse cohesion is applied by mechanically or hydraulically acting means. A method for producing a unidirectional fiber layer according to any one of claims 23 to 27, having a basis weight of at most 300 g / m ² as an intermediate product, wherein on a bobbin a plurality of closely and parallel juxtaposed tapes is wound, which are formed by widening of fibers formed from a plurality of filaments, characterized in that each individual band (3, 3a, 3b, 30) is provided with means for achieving transverse cohesion, but that the bands (3, 3a, 3b, 30) are laterally unwound wound on a bobbin (12) formed bobbin. Unidirectional fiber layer having a basis weight of at most 300 g / m ² , consisting of a layer of parallel juxtaposed tapes, which are formed by widening fibers, which in turn consist of a plurality of continuous or discontinuous filaments and are provided as a starting material with a sizing , characterized in that in the region of the boundary surfaces between the individual bands (3, 3a, 3b, 30), the adhesion effect of the size is reduced and the bands (3, 3a, 3b, 30) are substantially unconnected. A method for producing a unidirectional fiber layer according to claim 29, having a basis weight of at most 300 g / m ² as an intermediate product, wherein a coil body, a plurality of closely and parallel juxtaposed bands is wound, which are formed by widening fibers, which consists of a Variety of filaments are formed and provided with a size, characterized in that the adhesion of the size (4) is reduced and the bands (3, 3a, 3b, 30) incidentally querkohäsionsfrei and laterally unconnected to a disk coil (12) formed Bobbins are wound up. A bobbin having a unidirectional fiber ply as an intermediate in the manufacture of a multiaxial ply of any one of claims 28 or 30, wherein the unidirectional ply has a basis weight of at most 300 g / m ² and is formed of a plurality of closely spaced bands formed by widening of fibers, which in turn consist of a multitude of filaments,
characterized in that the bobbin as a disc coil (12) is formed and the bands (3, 3a, 3b, 30) of the unidirectional layer are laterally unconnected. Multiaxial scrim with the following features: a) the scrim consists of stacked unidirectional fiber layers; b) at least one fiber layer has a basis weight of at most 300 g / m ² and consists of parallel juxtaposed bands formed by widening fibers, which in turn consist of a plurality of continuous or discontinuous filaments and are provided as a starting material with a sizing ; c) the stacked unidirectional fiber layers are interconnected,
characterized, d) that the bands (3, 3a, 3b, 30) belonging to a unidirectional fiber layer are predominantly interconnected by the adjacent unidirectional fiber layers, e) that the lateral contact areas of the bands (3, 3a, 3b, 30) are substantially free of adhesion within a unidirectional fiber layer, f) and that the individual bands (3, 3a, 3b, 30) are each provided with a cross-cohesive agent. Multiaxial scrim with the following features: a) the scrim consists of stacked unidirectional fiber layers; b) at least one fiber layer has a basis weight of at most 300 g / m ² and consists of parallel juxtaposed bands formed by widening fibers, which in turn consist of a plurality of continuous or discontinuous filaments and are provided as a starting material with a sizing ; c) the stacked unidirectional fiber layers are interconnected,
characterized, d) that belonging to a unidirectional fiber layer bands (3, 3a, 3b, 30) are mainly interconnected by the adjacent unidirectional fiber layers, while e) the lateral contact areas of the bands (3, 3a, 3b, 30) are substantially free of adhesion within a unidirectional fiber layer, by reducing the adhesion of the size. Multiaxial scrim according to claim 32 or 33, characterized in that the material of the fibers (1, 1a, 1b, 30a) is carbon, ceramic, glass, aramid, a mixture thereof or consists of their precursors and intermediates. Multiaxial scrim according to one of claims 23 to 34, characterized in that the starting material used are fibers (1, 1a, 1b, 30a) with a filament number of at least 12K. Composite having a matrix and a reinforcing multiaxial scrim according to any one of claims 32 to 35 made according to a method of any one of claims 1 to 20.

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