MXPA06008004A - A fibre mat and a method of manufacturing a fibre mat - Google Patents

Abstract

The invention relates to a method of manufacturing a fibre mat adapted for use in the manufacture of a fibre-reinforced device, said fibre mat comprising at least two essentially longitudinally extending and parallel batches offibres. Novel aspects of the method according to the invention involves that the method comprises that the batches are joined by holder means that span above or below each batch, whereby the holder means impart an influence to each batch which is essentially symmetrical about an axis situated longitudinally between the batches. A symmetrical influence about an axis longitudinally between the batches accomplishes that influence from one side is matched by influence from an opposite side. Hereby it is prevented that the batch will undulate. Simultaneously the batches are clearly separated, whereby resin is more easily conducted longitudinally of the batches.

Description

FIBER MAT AND METHOD OF MANUFACTURE OF FIBER MAT DESCRIPTION OF THE INVENTION The invention relates to a method of manufacturing a fiber mat adapted for use in the manufacture of a fiber reinforced device, the fiber mat comprises at least two batches of fibers extending essentially longitudinally and parallel, optionally in combination with one or more carrier layers and a fastener such as a strand or the like. The invention is further related to a fiber mat and the use of a fiber mat. It is commonly known to use fiber mats consisting of unidirectional batches of fibers to build laminates for various fiber reinforced plastic objects including, for example, large objects, i.e., sheets for wind power plants, for use in the fiber industry. boats, the airplane industry, the vehicle industry and for structural elements. The batches can be fixed to the underlying layers of other batches or a felt carrier layer by means of stitches for what is referred to as a "knitted seam". In popular terms, that kind of sewing is described as a zigzag stitching made with a thread through each of the individual batches of the mat. However, the knitting stitch is associated with the drawback that the fibers are altered by the stitch and acquire a sinusoidal curved line shape in the longitudinal direction of the fibers with a "twist" for the attachment of each strand to the stitch. Carrier layer which is due to the pulling forces of the thread. In the case of batches of thin fibers, for example carbon fiber with thicknesses of less than 7 μm, the respective batches are fastened in such a way, when they are knitted with knitted stitches, so that they undulate in a different undulating manner in the same direction. the longitudinal direction. Such undulating batches are completely undesirable and involve a marked reduction in strength properties in the finished laminate and particularly when it comes from compressive strength. If the tension in the strand is reduced to counteract the wavy, the effect is that the batches can be compressed to be flat which can result in a reduced and damaged molding process, since the distribution of the resin becomes more difficult , since the compressed batches can have a blocking effect on the transport of the resin in the thickness direction of the laminate. This can be applied when the oldering technique used is the VARTM process (Vacuum Assisted Resin Transfer Molding). As indicated, during the molding process the relevant resin is sucked into the dry layers of fiber mats by means of. subatmospheric pressure in the mold. Therefore, it is very important that the resin be longitudinally or transversely flowing layers in a comparatively unimpeded manner and at a certain depth of the layers. An object of the invention is to provide a fiber mat and a method of making a fiber mat, wherein the batches of fibers are joined in a manner by which the batches do not undulate and which therefore do not involve a loss of resistance in compression. It is also an additional objective to avoid that batches of fibers are compressed during molding and have a damaged effect on the transport of the resin. Other objectives will be evident from the description. The novel aspects of the method according to the invention involve that the method comprises the joining of the batches by the fastener that encompasses each batch in an angle such that the fastener influences in each batch essentially symmetrically about an axis located longitudinally between the lots. The symmetric influence around an axis longitudinally between the lots means that the influence from one side is made to coincide with the influence from the opposite side. Therefore, the batch is avoided; however, due to the symmetric influence it can be sufficiently powerful to fix the batch to the effect that it is not compressed to be flat during molding. Simultaneously, the batches remain clearly separated, so that the resin is transported more easily longitudinally, transversally and in depth, in relation to the batches. Without the undulations, the lots are straight and direct and therefore have superior properties in compression. In two embodiments, the fastener may comprise at least one strand which is transported in a predetermined pattern above or below, respectively, of each of the batches. Therefore, the method can be practiced in plants of the prior art for making fiber mats, wherein the process • Processing includes stitching. In one embodiment, the strand can be configured transversely to the batches in a direction which is essentially perpendicular to the longitudinal direction of the batches. Therefore, the influence on the strand over the lots becomes symmetric around an axis between the lots. According to a preferred embodiment, at least one strand can be transported in a pattern comprising transverse seams. The seams - Crosses can be smoothed so that they are symmetrical and therefore eliminate the influence on the lots between them. According to a preferred embodiment, at least one strand is transported in a pattern comprising stitches that are longitudinally distributed between the lots. According to a preferred embodiment, the fiber mat further comprises at least one first carrier layer on which the batches are secured by the fastener. When batches are secured to the carrier layer, the carrier layer helps keep the batches together. By using a very thin carrier layer, the draping of the bound lots is maintained, while simultaneously retaining the advantages referred to above. In addition, the production technical advantages are carried out since, when an underlying carrier layer is used, it is only necessary to keep the fastener means transverse to the batches on the upper face and not on the lower face. According to a further preferred embodiment, the strand can be transported in stitches having a lencorresponding to one to ten times the width of the neighboring lot, whereby it is carried out that an appropriate lenis imparted to the stitches and by therefore at the distance between the securing points of the batches on the carrier layer. Too close stitches will mean that an unnecessarily excessive amount of thread will be used, while too long stitches mean imprecise assurance of the lots. A further preferred embodiment may comprise a means that is provided to handle a number of strands, and a means for handling a carrier layer and a number of batches of fibers, and wherein most of the batches are secured by the steps of : a) a number of needles, each having a needle eyelet which is a set of first positions between the batches transported through the carrier layer from a side which is located opposite the batches; b) at least two strands with a size adapted to each eye; c) the buttonholes are closed; d) the needles are pushed through the carrier layer in such a way that at least two strands form a loop; e) the buttonholes are opened, and the threads are let go; f) each needle is transported through the loop that has been formed in step d) of at least two strands; g) the needles in a set of deviated positions are transported through the carrier layer; h) at least two other strands that have an adequate size for the buttonhole; i) the needles are pulled through the carrier layer so that at least two strands form a loop; wherein each of the two strands, before step b) are transported from opposite sides above or below the neighboring batch of fibers. In this way, the binding of the batches is ensured as the threads are fixed against the carrier layer in seams that are secured through the carrier layer by the loops. In this way, the method can be carried out longitudinally with respect to the batches and will therefore be suitable for automated processing since the steps can be performed again and again to produce fiber mats of a very long len A further preferred embodiment may comprise providing means for managing a number of threads and a means for handling a carrier layer and a number of batches of fiber, and wherein most of the batches are set in the stages of: j) a number of needles, each having a needle eyelet, which is in a set of first positions between the batches transported through the carrier layer from a side that is located opposite the batches; k) at least two strands have an adequate size for each eyelet; 1) the buttonholes close; m) the needles are pulled through the carrier layer in such a way that at least two strands form a loop; n) the eyelets are opened, and the threads are let go; o) each needle is transported through the loop that is formed in step m) of at least two strands; p) the needles in a set of deviated positions in the container layer are transported through the carrier layer; k) at least one strand has a size for the eye; r) the needles are pulled through the carrier layer such that at least one thread forms a loop; wherein each of the two strands is transported, before step k) in a predetermined pattern, which includes from opposite sides above or below, respectively, a neighboring lot of fibers and longitudinally between a first and second neighboring lots.

In this way the method can be carried out longitudinally of the batches and furthermore it will be suitable for an automated process since the steps can be repeated again and again to produce very large fiber mats. By this method it is further carried out that the seams can also be distributed longitudinally in the batches, and that all the threads are used to form all the loops, so that savings in the number of threads can be generated. In a further preferred embodiment,. the fastener may comprise a second carrier layer which is fixed to the first carrier layer by at least three rows or joints joints which extend in parallel, whereby the first and second carrier layers with the joints form a number of conduits in the which are distributed batches. Therefore, the first and second carrier layers can cooperate for an accurate closure of the batches of fibers and therefore they are not allowed to ripple. In addition, it is ensured that the resin can be transported easily in the area between two neighboring conduits. By a specific embodiment, the joints or rows of joints can be formed by a process that is selected from a group comprising sewing, gluing and welding. These procedures are easy to carry out and simultaneously provide reliable operation. When the joints are made in rows there may be a distance between the joints longitudinally to the lots, so it is also allowed that the resin can be transported more easily across the lots, between the joints. According to a convenient embodiment, the first carrier layer can be selected from a group comprising a material which is permeable to resin, which is included in the form of fibers placed diagonally or transversely in relation to the batches of fibers, a material not woven, braided fibers and woven fibers include glass fibers. According to another preferred embodiment, the strands can be transported with a tension force which is adapted in such a way that a rounded contour is imparted to the batches in the transverse direction. In this way it is ensured that there is ample space for transporting resin between neighboring lots. According to a further preferred embodiment, the amount of fibers in the batches can be adapted in relation to the size of the ducts whereby a rounded contour is imparted to the batches in the transverse direction. Therefore, in this embodiment, too, ample space is provided to transport the resin between neighboring lots. Agree . With a convenient embodiment, the batches may comprise fibers which are selected from a group comprising glass fibers, carbon fibers, fibers having less electrical resistance than glass fibers and combinations of fibers of various materials. The novel aspects of the fiber mat according to the invention involve that it is adapted for use in the manufacture of a fiber reinforced device and that it comprises at least two batches of fibers extending essentially longitudinally and parallel, wherein the batches are joined by a fastener that covers each batch at an angle for the effect that each batch is influenced, which influence is essentially symmetrical about an axis located longitudinally between the batches. A symmetrical influence about an axis longitudinally between the batches is carried out in such a way that the influence of one side is made to coincide with the influence of the opposite side. In this way, the batches are prevented from undulating. In addition, it is carried out that the batches can be tightly fixed so that they are prevented from compressing to be flat during molding. Simultaneously, the batches are clearly separated, so that the resin is transported more easily in the transverse direction, longitudinally and deep in the lots. If in the undulations, the lots are straight and direct and therefore have superior compression properties. Suitable embodiments of the fiber mat appear in claims 17-26. A fiber mat according to one or more of claims 16-26 can advantageously be used in RTM molding of a fiber-reinforced device or VARTM, laid by hand or prepeg (wet or dry), respectively. Precisely, by a VARTM molding, the improved property with respect to conductivity is particularly advantageous. According to a particularly advantageous embodiment, the aforementioned fiber mats can be used in the molding of a device which is configured to form a blade for a wind power plant including, for example, the cover of a blade or a beam of reinforcement. Such vanes have a very large length and a portion of the fibers are often distributed so that they extend to • through the full length of the blade. In this way, the improved property with respect to the resin conductivity is particularly advantageous. Also the improved properties in compression have a great value, since both sides of the blade can be exposed to large loads that resist compression. A more detailed description of the invention provided with respect to the figures exemplifying embodiments of the invention follows: Figure 1 is a sectional view, seen from the top, of a fiber mat according to the invention; Figure 2 is a sectional view, seen from the top, of an alternative configuration of a fiber mat according to the invention; Figure 3 is a sectional view, seen from the top, of a fiber mat of the prior art; Figure 4 is a schematic view of the transport of two strands in a pattern; Figure 5 is a schematic view of the transport of three strands in a pattern; Figures 6-12 are schematic views of the transport of one or more strands, respectively, in different patterns; and Figure 13 shows a further embodiment of a fiber mat according to the invention, seen at an inclined angle in a front view, laterally and from the upper part. Figure 1 shows a fiber mat 1 comprising a number of batches of fiber 2 that are fixed to a non-visible carrier layer 3. The fastener in the form of strands 6 and 11 keeps the batches securely attached to the non-visible carrier layer. The strands 6 and 11 are transported so as to comprise transverse seams 10 and straight seams 9 which are distributed in parallel with the batches 2. The seams 10 influence the batches 2 symmetrically about an axis 5 longitudinally between the batches, as described in • the figure. Each batch 2 has a width B, but may also have other widths, and likewise, different types of fibers may exist from one batch to the other and within individual batches. Therefore, batches comprising glass fibers and carbon fibers mixed in a fixed ratio can exist. Figure 2 shows a fiber mat 1 comprising a number of batches of fibers 2 which are secured to a non-visible carrier layer 3 '. The fastener means in the form of strands 6 and 11 keeps the batches 2 secured to the non-visible carrier layer. The strands 6 and 11 are transported so as to compress the transverse seams 10. The seams influence the batches 2 symmetrically around an axis not shown longitudinally between the batches, and in this way prevent the 2 curl. An apparent line of symmetry will appear from FIG. 1. Between rows 2, individual loops 14 will appear that fix the stitches 10. FIG. 3 shows a fiber mat 1 of the prior art with batches 2 of fibers. By means of a strand 6, the batches 2 are fixed by knitted stitching which extend in a zigzag-like pattern. which are non-symmetrical about any longitudinal axis of the lots. A built-in curve emphasizes the manner in which the batches 2 are undulated, which is, as previously mentioned, undesired. Figure 4 shows a fiber mat 1 comprising a carrier layer 3 which is simply delineated and presented transparently. The batches of fibers are not shown. The strands 6 and 11 are transported so as to comprise transverse seams. Furthermore, the figure shows that the strands 6, 11 are pulled as one descends within a loop 14 that is to be perceived as being distributed on one side of the carrier layer 3, while the stitches 10 are distributed on the opposite side of the layer 3 carrier. In Figure 11 a corresponding modality is shown. The batches not shown are distributed between the carrier layer 3 and the seams 10. The transport of the strands 6 and 11 is carried out so that a needle not shown, which has a buttonhole is in a first position between the batches not shown, is transported through the carrier layer 3 from one side which is placed opposite the batches, and two strands 6, 11, which have a size for each buttonhole, follow each of the buttonholes that are closed and the threads are secured in the buttonholes. Then, the needle is pulled through the carrier layer 3 so that the two strands 6, 11 form a loop 14, following the buttonhole which opens and the threads are free. Then, the needle is transported through the loop 14 that has been formed of the two strands 6, 11 that were made before, after which the needle is again in a deviated position of the carrier layer 3, transported through the same and two other strands with placed by the buttonhole and pulled through the carrier layer, so that a new loop is formed, and so on. The threads in this way are transported in such a way that they influence the batches not shown symmetrically by the threads and therefore will not ripple. Figure 5 also shows a fiber mat 1 which also comprises a carrier layer 3 which is simply delineated and shown as transparent. Batches of the fibers are not shown. This seam comprises the transport of three strands 6, 7 and 11 which are transported in a manner that includes both transversal and longitudinal seams 9 and 10. Furthermore, the figure also shows the strand 7 alone and the strands 6, 7 and 11 together, respectively, which are pulled down in a loop 14 that is to be perceived as distributed on one side of the carrier layer 3, while the strands Seams 9 and 10 are located on the opposite side of the carrier layer 3. In Figure 12 a corresponding modality is shown. The batches not shown are distributed between the carrier layer 3 and the seams 9 and 10. The transport of the strands 6, 7 and 11 is carried out by a needle not shown with an eyelet that is in a first position between the lots. not shown, transported through the carrier layer 3 from a side placed opposite the batches and three strands 6, 7 and 11 that are placed in each buttonhole, after which the buttonhole is closed, the strands are attached to the buttonhole. The needle is then pulled through the carrier layer 3 whereby the three strands 6, 7 and 11 form a loop 14 after which the eye is opened and the strands are released. Subsequently the needle is transported through the loop 14 which is formed by the three strands 6, 7 and 11 that have been formed before, after which the needle is in a position deviated from the carrier layer 3, and is transported back to through it and a strand 7 that is placed in the buttonhole and pulled through the carrier layer, so that it forms a new loop, and so on. In this way, the strands are transported in such a way that they influence the batches not shown, symmetrically by the strands and therefore will not undulate. Figures 6-12 show embodiments comprising eg the manner in which the strands according to the invention can be transported so as to influence one or more batches of fibers symmetrically. The carrier layer is not shown in Figures 6-8 and 10-12. Instead of this the circles 8 indicate points of passage of the strands where one or more needles, respectively, are transported through the carrier layer not shown and have pulled the strand or threads down through the carrier layer where after a loop is formed, not shown. A loop will appear from figure 4 and figure 5. The needles are then taken through the loop and in a deviated position are again transported upwards, through the carrier layer and at least one strand is drawn downwards as far as possible. length of a new loop formed, and so on. For purposes of a review, carrier layer 3 and loop 14 are not shown in Figures 6-8 and 10-12. The delineated union of the lots in Figure 9 is without a carrier layer and here the circles indicate the place where one or more needles, respectively, are transported on the other side of the lots.

In Figure 6, two strands 6 and 11 are transported in seams extending perpendicular to. the longitudinal direction of the lots and longitudinally thereof, respectively, see the seams designated as 16 and 9. In this context, a seam should be seen as the strand which is between two successive points of passage, indicated by the circles 8. In Figure 7, two strands 6 and 11 are transported in seams comprising the straight seams 9 and the transverse seams. In Figure 8 two strands 6 and 11 are transported in seams that only comprise transverse seams. Figure 9 schematically shows a union of two batches without a carrier layer, wherein the four strands 6 and 11 are transported in transverse seams above as well as below the batches, whereby the strands influence each batch symmetrically around each batch. an axis longitudinally of the lots. Figure 10 shows the transport of two strands 6 and 11. In the case of three lots 2, eight strands can be used, but six will be sufficient, since the outer ones are taken alone in 9 straight stitches that do not help to secure lots 2. Strands 6 and 11 are transported through a point of passage 8 in a first position 17. The strands are then taken diagonally in each of their directions in the form of transverse seams 10 and towards positions 19 and 21, respectively, after which they are again carried together at position 20. When looking longitudinally at lots 2, position 18 is the next one observed in relation to position 17; however, in position 18 two other strands are worn together, although preferably with the same set of needles not shown. Therefore, a loop of strands 6 and 11 is made, not shown, by the strands that are joined in position 18 and again in position 20. Loops not shown in this way are caused to be placed longitudinally between the positions 17 and 18 as well as 18 and 20. Figure 11 shows another way of transporting the strands. In principle, the difference compared to Figure 10 is that the transverse seams 10 are distributed at intervals in which they were created by a set of transverse seams 10 which are replaced by a set of straight seams 9. The strands 6 and 11 are transported through a passage point 8 in a first position 17. The strands are then transported diagonally each in their direction, in the form of transverse seams towards the positions 19 and 23, respectively, after which are transported in straight seams to the position 20 and 24, respectively, after which they are assembled again in the position 21. In this way a loop not shown of the strands 6 and 11 is elaborated by means of the strands that are they are brought together to position 18 and again in position 20. By this mode a more flexible mat design mode is completed which can be smoothed more easily on a curved or double curved molded surface, for example in connection with the molding of VARTM. Figure 12 shows the way to transport three strands. In principle, the difference with respect to Figures 10 and 11 is that the third strand 7 is transported only essentially at the seams 9 longitudinally between the lots. The loops not shown are formed as shown in Figure 5 from an alternating seam 7 and three strands 6, 7 and 11. By this mode, a mat with a greater drape is obtained which is easier to smooth on a surface of curved or double curved mold, for example in relation to a VARTM molding. In the embodiments shown in Figures 10-12, the needles not shown are preferably kept in the same place, while the strands move laterally and the various longitudinal positions of the lots 2 are obtained by displacement of the batches 2., which include the carrier layer, not shown. The opposite is also possible, but it is hardly practical. Of course in practice, the examples that. shown in Figures 6-12 will comprise many more batches 2, since the width B of batches 2 can typically be a few millimeters. In this case, of course, more threads need to be used but the same fundamental principles apply. Figure 13 shows an embodiment of a fiber mat 1 comprising a first carrier layer 3 and a second carrier layer 12 which are joined to produce a number of conduits 13 in which batches 2 of the fibers can be distributed. The carrier layers 3, 12 can be connected continuously or in rows of joints, that is to say for example with a distance between the joints. Joints can be made, for example, by stitching, gluing or welding. The carrier layers 3, 12 are preferably made of a material which is a non-woven material, permeable to resin, braided fibers or woven fibers, including glass fibers. It will be understood that the invention, as described in the present description and in the figures, can be modified or changed but still remain within the protective scope of the following patent claims.

Claims (28)

1. A method for manufacturing a fiber mat adapted for use in the manufacture of a fiber-reinforced device, the fiber mat comprises at least two batches of fibers extending substantially parallel and longitudinally, wherein the method comprises that the fibers Bundles are joined by a fastener that encompasses each batch at an angle such that the fastener imparts an influence to each batch influence which is essentially symmetrical about an axis located longitudinally between the batches. Method as described in claim 1, wherein the fastener comprises at least one strand which is conveyed in a predetermined pattern over at least one of the batches. Method as described in claims 1 to 2, wherein the fastener comprises at least one strand which is conveyed in a predetermined pattern below at least one of the batches. 4. Method as described in one or more of claims 2 to 3, wherein at least one strand is transported in a pattern comprising transverse seams. Method as described in one or more of claims 2 to 4, wherein at least one of the strands is transported in a pattern comprising seams that are to be distributed longitudinally between the batches. Method as described in one or more of claims 1 to 5, wherein the fiber mat further comprises at least one additional carrier layer; and in the method comprises that the batches are fixed to the carrier layer with the fastener means. Method as described in one or more of claims 2 to 6, wherein the strand is transported in seams having a length corresponding to one to ten times the width of the neighboring lot. 8. A method as described in one or more of claims 2 to 7, wherein a means is provided for handling a number of strands and a means for handling a carrier layer and a number of fibers; and where most of the batches are secured by the steps of: a) a number of needles, each needle has an eyelet, where in a set of first positions between the batches transported through the carrier layer form a side which is located opposite the lots; b) at least two strands are placed in each buttonhole; c) the buttonholes are closed; d) the eyelets are pulled through the carrier layer so that at least two strands form a loop; e) the buttonholes are opened and the strands are released; f) each needle is transported through the loop that is formed in step d) of at least two strands; g) the needles in a set of deviated positions are transported through the carrier layer; h) at least two other strands are placed in the eyelets; i) the needles are pulled through the carrier layer so that at least two strands form a loop; wherein each of at least two strands is transported, before step b) from opposite sides above or below the neighboring fiber batches. 9. Method as described in one or more of claims 2 to 7, wherein means are provided for managing a number of strands and means for handling a carrier layer and a number of batches of fibers, and wherein the majority of the batches are secured in the stages of: j) a number of needles, each needle having a needle eyelet, wherein a set of first positions between the batches transported through the carrier layer form a side that is located opposite to the batches; k) At least two strands are placed in each buttonhole; 1) the buttonholes close; m) the needles are pulled through the carrier layer in such a way that at least two strands form a loop; n) the eyelets are opened, and the threads are released; o) each needle is transported through the loop that is formed in step m) of at least two strands; p) the needles in a set - - of deviated positions in the carrier layer are transported through the carrier layer; k) at least one strand is placed in the buttonhole; r) the needles are pulled through the carrier layer such that at least one thread forms a loop; wherein each of at least two strands is transported, before step k) in a predetermined pattern, preferably including from opposite sides above or below, respectively, a neighboring lot of fibers and longitudinally between a first and a second neighboring lots. A method as described in claim 6, wherein the fastening means comprises a second carrier layer which is secured to the first carrier layer by at least three rows or joints joints which extend in parallel, so that the first and second carrier layers with the joints form a number of conduits in which the batches are distributed. 11. Method as described in claim 10, wherein the joints or rows of joints are configured by a method that is selected from a group comprising sewing, gluing and welding. Method as described in one or more of claims 6 to 11, wherein the first carrier layer is selected from a group comprising a material which is permeable to resin, which is included in the form of fibers placed diagonally or transversely in relation to lots of fibers, a non-woven material, braided fibers and woven fibers, including glass fibers. Method as described in one or more of claims 1 to 9, wherein the strands are transported with a tension force adapted in such a way that a rounded contour is imparted to the batches in the transverse direction. 14. Method as described in the claim 10 or 11, wherein the quantity of fibers in the batches is adapted in relation to the size of the ducts with the effect that the rounded contour is imparted to the batches in the transverse direction. A method as described in one or more of claims 1 to 14, wherein the batches comprise fibers that are selected from a group comprising glass fibers, carbon fibers, fibers having less electrical resistance than glass fibers and combinations of fibers of different materials. 16. Fiber mat adapted for use in the manufacture of a fiber reinforced device, fiber mat which comprises at least two batches of fibers extending essentially longitudinally and parallel, wherein the batches are joined by a fastener which covers each batch at an angle, so that an influence is imparted to each batch, the influence is essentially symmetrical about an axis located longitudinally between the batches. 17. Fiber mat, as described in claim 16, wherein the fastener comprises at least one strand which is conveyed in a predetermined pattern over at least one of the batches. 18. Fiber mat, as described in claims 16 to 17, wherein the fastener means comprises at least one strand which is conveyed in a predetermined pattern below at least one of the batches. Fiber mat, as described in one or more of claims 17 to 18, wherein at least one strand is transported in a pattern comprising transverse seams. 20. Fiber mat, as described in one or more of claims 17 to 19, wherein at least one strand is transported in a pattern comprising seams that are longitudinally distributed between the batches. 21. Fiber mat, as described in one or more of claims 16 to 20, wherein the fiber mat further comprises at least one first carrier layer; and understands that the batches are secured to the carrier layer by the fastener. 2

2. Fiber mat, as described in one or more of claims 17 to 21, wherein the strand is transported in seams having a length corresponding to one to ten times the width of the neighboring lot. 2

3. Fiber mat, as described in claim 16, wherein the fastener comprises a second carrier layer which is secured to the first carrier layer by at least three joints or rows of joints extending in parallel, thereby the first and second carrier layers with the joints form a number of conduits in which the batches are distributed. Fiber mat, as described in claim 23, wherein the joints or rows of joints are configured in a process that is selected from a group comprising sewing, gluing and welding. 25. Fiber mat, as described in one or more of claims 16 to 24, wherein the first carrier layer is selected from a group comprising a material which is permeable to resin, which is included in the form of fibers. distributed diagonally or transversally in relation to batches of fibers, a non-woven material, braided fibers and woven fibers, including glass fibers. 26. Fiber mat, as described in one or more of claims 16 to 25, wherein the batches comprise fibers that are selected from a group comprising glass fibers, carbon fibers, fibers having less electrical resistance than the fibers. Glass fibers and fiber combinations of various materials. 27. Use of a fiber mat, as described in one or more of claims 16 to 26, wherein the use comprises VARTM molding of a fiber reinforced device. 28. Use as described in the claim 27, wherein a device that is configured to be a constituent in or part of a blade for a wind power plant is molded.