Fabrics and methods

Abstract

A seam felt for use in the press section of a machine for producing a fabric, in particular a fiber web, and a method for producing the same, the fabric having at least one base structure and at least one laminated fiber layer arranged on the base structure, the at least one laminated fiber layer being arranged on the side facing the fiber web, the fabric having at least one seam zone, in which the seam loops are connected to one another by at least one insert wire so as to make the fabric seamless, the at least one laminated fiber layer being divided in the area of ​​the seam zone by at least one cut, thereby forming seam flaps and seam wedges, wherein the laminated fiber layer comprises a quantity of bonding fibers in the area of ​​the seam zone, both in the seam flap and in the seam wedge, which bonding fibers are bonded to one or more further laminated fibers by welding.

Description

[Technical field]

[0001] The present invention relates to a seam felt for use in the press section of a machine for producing fabrics, in particular textile webs, according to the preamble of claim 1, as well as to a method for producing same according to claim 9.

[0002] With regard to fabrics for paper machines, in particular press felts, the development has already shifted from seamless fabrics to seam fabrics. The advantage for the user is that the seam fabrics can be easily installed on the machine. Furthermore, since it is not necessary to take measures for fitting the seamless fabrics in new installations, a great deal of construction effort can be saved.

[0003] A special seam felt is produced by means of a plug-in wire seam which joins the felt ends in the region of the backing. A nonwoven layer is applied and needled onto this backing, which is thus made seamless, at least on the paper side, but often also on the running side. Since this is advantageous from a production standpoint, the nonwoven layer is also needled on the plug-in wire seam.

[0004] To pull the felt into the paper machine, the seams of the felt must be reopened, which is possible without problems in the base fabric by removing the insert wires, but the nonwoven layer that has been needled across the seam must be unwound.

[0005] For this purpose, the paper-side nonwoven layer of one felt end is separated from the paper-side nonwoven layer of the other felt end in the region of the plug wire by an incision, which is made into the still-closed nonwoven after needling across the seam. This incision can be made vertically, but is preferably made slightly inclined, i.e. preferably at an offset of 5-30° from the vertical, so that seam flaps and seam wedges are formed.

[0006] After the felt is pulled in, the plug wire seam is closed again, for example by a plug wire in the form of a fiber bundle. However, the separated ends of the nonwoven support are not closed again with the same dimensions. At this point, the felt or the nonwoven support has different properties than the rest of the felt. Moreover, this point is also a weak point where the felt can be damaged, mainly by abrasion.

[0007] In order to improve the wear resistance, it is known from the prior art, for example from document DE 102019134837 A1, to reconnect the seam flap and the seam wedge to one another. For this purpose, in DE 102019134837 A1, additional connecting elements are used.

[0008] However, the drawback remains that the seam wedges, and especially the seam flaps, are themselves highly susceptible to wear.

[0009] The object of the present invention is therefore to propose a seam area for a fabric which is more abrasion resistant than the prior art, without adversely affecting the permeability of the seam area.

[0010] A further object of the present invention is to provide a fabric which is easy to manufacture and which can be easily loaded onto a machine.

[0011] This problem is solved according to the invention by the features of claim 1 as well as by a method according to claim 9.

[0012] Further advantageous embodiments of the invention are set forth in the dependent claims.

[0013] With regard to the fabric, this problem is solved by a seam felt for use in the press section of a machine for producing a fabric, in particular a fiber web, which has at least one base structure and at least one laminated fiber layer arranged on the base structure, the at least one laminated fiber layer being arranged on the side of the base structure facing the fiber web. The base structure may in particular be a base fabric.

[0014] The fabric has at least one seam zone, in which the seam loops are connected to one another by at least one insert wire to make the fabric seamless, and at least one laminated fiber layer is divided in the area of ​​the seam zone by at least one incision, thereby forming a seam flap and a seam wedge.

[0015] According to the invention, it is envisaged that at least one laminated fibrous layer comprises a certain amount of bonding fibres in the area of ​​the seam zone, both in the seam flaps and in the seam wedges, which bonding fibres are bonded to one or more further laminated fibres by welding.

[0016] In this case, it is assumed that no welding takes place between the lamination fibers of the seam flap and the lamination fibers of the seam wedge, so that the connecting fibers of the seam flap are only connected to the lamination fibers of the seam flap, whereas the connecting fibers of the seam wedge are only connected to the lamination fibers of the seam wedge.

[0017] In a preferred embodiment, the bonding fiber is assumed to at least partially absorb light having a wavelength in the NIR range of 780 nm to 3 μm. By the bonding fiber at least partially absorbing light having a wavelength in the NIR range of 780 nm to 3 μm, it is possible to perform transmission welding, for example laser transmission welding, of the laminated fibers.

[0018] Alternatively, this can also be done by a simultaneous welding method on the laminated fiber layers in the seam area. In this case, multiple laser beams are directed simultaneously or at short intervals from different directions at the area to be welded, and these laser beams have enough energy only at their intersection points to weld the fibers, thus causing material melting and material-connecting bonds at these points. For this, special fiber materials that are absorbent within a certain wavelength range are not necessarily required. The wavelength of the laser can be adjusted to the absorption of the fiber material. It is therefore desirable for the fiber material to only partially absorb the light of the laser, i.e. less than 50%, preferably less than 30%.

[0019] This method can be designed so gently that the properties of the seam zone, such as for example the permeability, are not or only slightly changed by the welding, which is an advantage over ultrasonic welding, for example, which is also possible in principle.

[0020] The welding of the binding fibers to the other layer fibers can also be distinguished from the use of so-called BiCo fibers or melt-adhesive fibers, which contain two components, for example polyamides with a sheath made of a copolyamide with a lower melting point. In this case, it is true that a bond between the layer fibers can also be produced by heating the felt and melting the corresponding BiCo fibers. Such a bond corresponds rather to gluing or brazing. In this case, such a bond is weaker than a weld and breaks relatively quickly during operation of the felt. The aim of high wear resistance is therefore not achieved to the same extent by such fibers or by such adhesive bonds as by the above-mentioned bonds by welding.

[0021] The binding fibers as part of the laminate fiber layer are also configured in this case as laminate fibers, so that they can also be processed without problems together with the remaining laminate fibers, which are not absorbing in the corresponding wavelength range.

[0022] Within the scope of the present application, a seam zone is understood to mean the area around the insert wire seam, in which the bonding fibers are bonded by welding to other lamination fibers of at least one laminated fiber layer.

[0023] The seam zone typically extends across the entire width of the fabric in the cross machine direction.

[0024] The inventors have realized that the welding of the laminated fibers in at least one laminated fiber layer clearly increases the internal strength of this section of the laminated fiber layer around the seam, which provides several advantages: firstly, the incisions for forming the seam flaps and seam wedges can be performed more easily and precisely if the seam zone is reinforced;

[0025] Furthermore, both resulting parts (flaps and wedges) are significantly more resistant to abrasion, i.e., cutting would normally result in smaller fragments of the laminated fibers, which could relatively easily peel off from the nonwoven composite. By welding the laminated fibers together, these fiber fragments are now no longer only mechanically (i.e., by entanglement) but also materially connected to the composite of the laminated fiber layers, so that this risk is at least significantly reduced.

[0026] Furthermore, the seam flap as a whole is significantly more shape-stable. The seam flap has a triangular shape - with a more or less acute angle depending on the incision angle. In this case, the leading edge of the triangle is generally a weak point, which can be bent away from the fabric surface due to the different loads in the paper machine. Due to the welding of the nonwoven fibers in the seam zone, this leading edge is reinforced and the risk of bending is reduced.

[0027] Such reinforced seam zones also facilitate easier loading of the fabric on the machine.

[0028] Due to the absence of welding between the seam flap and the seam wedge, the seam can be reopened if necessary.

[0029] In particular, the binding fibers may have the same fiber count as the other layer fibers or may have the same fiber count as some of the other layer fibers of the layer fiber layer. The layer fibers that are not binding fibers may advantageously consist of polyamides, for example PA6 or PA6.6. Such polyamides are advantageous because they are completely or sufficiently transparent to light having wavelengths in the NIR range of 780 [nm] to 3 [μm]. The use of NIR transmission welding is therefore possible without problems.

[0030] It is particularly advantageous if the binding fibers consist of the same polymer as the other layered fibers, in particular polyamide. If welding is carried out by NIR transmission welding, the binding fibers can be made at least partially absorbent for light of wavelengths in the NIR range of 780 nm to 3 μm by certain additives.

[0031] A suitable additive for this purpose is, for example, soot (industrial soot, "carbon black"). The black-colored binding fibers thereby also fulfill the advantageous secondary effect that the seam zones are easily recognizable as black or relatively dark transverse strips of the fabric and are therefore also easy to find for opening the seams.

[0032] Alternatively, the bonding fibers and the other layer fibers may not be made of the same polymer, but each may be made of a weld-compatible polymer.

[0033] Advantageously, such seam zones are relatively short in the longitudinal direction, i.e. in the running or machine direction of the fabric.

[0034] In a preferred configuration, it may be envisaged that the seam zone extends in the longitudinal direction of the fabric over less than 100 mm, in particular over less than 50 mm, preferably over 30 mm. Seam zones having a length of 10 mm or less may also be envisaged.

[0035] Such short seam zones of less than 100 mm achieve the desired objective of stabilizing the laminated fiber layers in the area of ​​the seam flaps and seam wedges, and are furthermore simple to manufacture.

[0036] When welding of the binding fibers is performed, for example, by laser transmission welding, it is advantageous if the seam zone can be formed in no more than one pass of the laser head.

[0037] Typical laser optics have a width of, for example, 30 mm. A seam zone of 30 mm length can therefore be formed with just one pass of the laser head across the width of the fabric.

[0038] Particularly long seam zones of more than 10 cm, in particular 50 cm, 100 cm or even more, are possible within the scope of the present invention, but the additional length does not provide any significant advantage for the durability of the seam zone, so that the additional effort for welding is not necessary.

[0039] Outside the seam zone, bonding fibers may also be present in the laminated fiber layers, but these bonding fibers are not welded. This may occur for manufacturing reasons. Advantageously, however, outside the seam zone, the proportion of bonding fibers in the laminated fiber layers is smaller than in the seam zone. Preferably, outside the seam zone, no bonding fibers are present in the laminated fiber layers.

[0040] It may prove advantageous if in at least one laminated fiber layer the proportion of bonding fibers in the seam zone that at least partially absorb light having a wavelength in the NIR range of 780 nm to 3 μm is between 5% and 40% by weight, in particular between 15% and 30% by weight.

[0041] The fabrics according to the various aspects of the invention, in particular the felts, may be provided with at least one further laminated fiber layer arranged on top of the laminated fiber layer, such a further laminated fiber layer being capable of providing in particular the upper paper-contacting surface of the fabric and not containing bonding fibers.

[0042] This allows the top surface of the seam zone to have approximately the same surface characteristics as the rest of the fabric.

[0043] Regarding the method, the above problem is solved by a method for manufacturing a fabric according to an aspect of the present invention, which comprises the following steps: a. preparing a base structure and making the base structure seamless by introducing an insert wire into seam loops that are crossed over one another; b. placing a laminated fibrous layer on the side of the base structure facing the fibrous web, the laminated fibrous layer comprising a predetermined amount of bonding fibers in the area of ​​the seam loops, the bonding fibers preferably at least partially absorbing light of wavelengths in the NIR range of 780 nm to 3 μm; c. needling at least one laminated fiber layer to a base structure; d. fusing the bonding fiber to another laminated fiber to form a seam zone; e. incising the seam zone, thereby forming a seam flap and a seam wedge; Contains:

[0044] In the method described therein, in particular no method step is provided for welding between the laminated fabric of the seam flaps and the laminated fabric of the seam wedges.

[0045] If step e.) is carried out after step d.), this has the advantage that the formation of the incisions can be carried out more simply and precisely, thus also avoiding undesired inadvertent welding between the seam flap and the seam wedge due to the subsequent welding.

[0046] Nevertheless, there may be applications in which step e.) is performed before step d.).

[0047] The intensity of the laser radiation can be adapted to the material structure and the desired strength of welding and structure retention. Advantageously, pressure can also be applied to the seam area during welding. For example, this can be carried out by NIR transmission welding using a NIR laser welder Novolas with roller optics from Leister at a wavelength of 840 nm. In this case, a roller width of 30 mm can be used. The seam area is treated in this example with a laser power of 450 W at 5 m / min and a roller pressure of 15 N.

[0048] The advantages of the invention over the prior art are also particularly evident in the manufacturing process: in the fabrics according to DE 10 2019 134 837 A1, it is essential that the welding process must already be carried out while the fabric is being loaded onto the machine. For this reason, extensive safety measures must be taken precisely when using laser welding.

[0049] In the method described here, step d.) can be carried out without problems by the manufacturer, where the fabric can be processed in specially adapted and safe welding stations. The cutting of the seam zones can also be carried out without problems by the manufacturer.

[0050] The fabric can be tensioned on the machine after opening of the insert wire seam and then made seamless by closing the insert wire seam again. Since no welding is done between the seam flap and the seam wedge, no welding step is required in the manufacturing machine.

[0051] The seam zone according to the present invention can in principle be combined with various measures known from the prior art to further improve the abrasion resistance.

[0052] Thus, for example, it may be envisaged - in an embodiment not currently claimed - that at least one connecting element is inserted between the seam flap and the seam wedge, the at least one connecting element being material-connectively connected, in particular welded, to the laminated fibres of the seam flap and / or the seam wedge.

[0053] Such connecting elements are described, for example, in DE 10 2019 134 837 A1.

[0054] In this case too, it may be envisaged that the at least one coupling element comprises a polymer material that at least partially absorbs light having wavelengths in the NIR range of 780 nm to 3 μm.

[0055] In this case, such bonding elements are capable of absorbing light in the same wavelength range as the bonding fibers of at least one of the laminated fibrous layers.

[0056] However, it may also be advantageous if such bonding elements absorb in other parts of the NIR range. This can be achieved, for example, by adding different additives, even when the same polymer (e.g. polyamide) is used. Advantageously, welding of the bonding elements (e.g. by transmission welding) is carried out at different wavelengths, so that it has no or only little adverse effect on the laminated fiber layers.

[0057] The at least one connecting element is preferably configured as a thread-like or strip-like connecting element.

[0058] By providing such a connecting element, the advantage - especially in terms of production technology - of eliminating the welding between the seam flap and the seam wedge is certainly lost, but in special applications this disadvantage can be offset by the further extension of the wear resistance of the seam area.

[0059] example: The following examples are intended to illustrate typical felts according to the embodiments of the present invention, as well as steps for their manufacture. The present invention is not limited to these examples. It is clear to the skilled artisan that the individual aspects of the examples (lamination fibers, absorbent body, method steps, etc.) can also be advantageously used within the scope of the present invention independently of the combination of these examples.

[0060] A PA6 laminated fiber of 44 dtex and having an absorption of more than 80% at 940 nm is mixed as a bonding fiber with a PA6 laminated fiber layer of 44 dtex in a ratio of 30:70. The mixture is carded to obtain a fiber having a thickness of 150 g / m 2 A laminated fiber layer is produced (nonwoven fabric X).

[0061] As absorbents it is possible to use, for example, finely dispersed absorbent powders, such as soot powder (as a rule 0.25 to 2% by weight), which are coextruded with the polyamide, or known inorganic absorbent powders, such as LaB6 (as a rule 0.15 to 0.75% by weight).

[0062] The exemplary felt is constructed with a woven base structure, the paper side of which in this case is further provided with a row of further laminated fiber layers. 150g / m 2 The first separate laminated fiber layer comprises PA6.6 fiber of 44 dtex. On top of this first separate laminated fiber layer, a "nonwoven fabric X" laminated fiber layer is then placed. On top of this laminated fiber layer, 150g / m 2A second separate laminated fiber layer is placed comprising PA6 fiber of 22 dtex. On top of that is placed a third separate laminated textile layer comprising 6.7 dtex PA6 fibre.

[0063] The running side of the base structure is 150g / m 2 There may be provided a fourth separate laminated fibrous layer comprising PA6 fibres of 22 dtex.

[0064] An example of this is that, important according to this aspect of the invention, the laminated fibrous layer containing bonding fibers may be only a part of the nonwoven support on the paper side of the felt, here even less than half of the nonwoven support on the paper side of the felt.

[0065] The production can be carried out by the usual methods known to those skilled in the art, in which the various laminated fiber layers are applied one after the other and fixed to the base structure by needlework, one after the other. After all the laminated fiber layers have been fixed by needlework, several intensive needlework cycles follow. The seam zone covering the seam (15 mm before and after the seam, respectively, 30 mm in total) is then treated with a NIR laser (Leister Novolas Basic AT with roller optics, 940 nm wavelength) with a pressing force of 15 N, a passing speed of 5 m / min and a laser power of 450 W. This results in fused fiber-fiber bonds in the seam zone, where some of the bonding fibers are partially or completely melted and bonds between several fibers are created as brazing joints.

[0066] The entire seam felt is then preferably subjected to a further heat setting process. After that, the pins / inserted wires inserted for the heat setting process are removed and the welded fiber top layer is cut open along the seam. The detailed procedures for the individual steps are known to those skilled in the art of press felt manufacturing.

[0067] In the following, the invention is explained further with reference to the drawings, to which the invention is not restricted in this case. [Brief description of the drawings]

[0068] [Figure 1] FIG. 1 shows a portion of a fabric according to the prior art. [Diagram 2] FIG. 2 illustrates a portion of a fabric according to an aspect of the present invention.

[0069] FIG. 1 shows a part of a fabric 1 known from the prior art. In this case, the fabric comprises a base structure 3, which is configured as a base fabric 3. Each end of the base structure has one seam loop 4 in each case. Such seam loops 4 can be formed, for example, by folding and overlapping the base structure 3. In this case, the seam loops 4 are formed by warp threads (MD yarns) 6 of the base fabric 3. In order to further form the seam loops 4, individual weft threads (CD yarns) of the base fabric can be removed. The fabric 1 is made seamless in that both seam loops 4 are crossed over each other and joined by the introduction of an insert wire 5, which in this case can be a single filament. The fabric 1 in FIG. 1 shows an insert wire 5, which is alternatively formed from multiple filaments. The skilled person is otherwise largely free to choose a suitable insert wire 5. The advantages of the invention can be achieved regardless of the choice of the insert wire 5.

[0070] The fabric 1 further comprises a laminated fibre layer 8 and a further laminated fibre layer 8b. In this case, the laminated fibre layer 8b on the running side can possibly be omitted. The laminated fibre layer 8 on the paper side is consistently applied onto the base structure 3, in particular by needling. In order to be able to open the fabric 1 for pulling into the machine, the laminated fibre layer 8 is opened by an incision 9 across the seam. This incision 9 can in principle also be made vertically. However, as is usually the case, the incision 9 is made obliquely, i.e. at an angle to the vertical, as shown in FIG. 1. This angle is preferably between 5° and 30°. This results in a seam flap 10 and a seam wedge 11. In this case, the seam flap 10 overlaps the seam wedge 11 in the closed fabric 1.

[0071] In cross section, the arrangement shown in Fig. 1 exemplarily has three connecting elements 20 inserted therein. These connecting elements 20 are each configured as threads extending across the entire transverse direction of the fabric 1 or the incision 9. As threads 20, for example, monofilaments, multifilament bundles or twisted threads can be used. Also, more or less than the three threads 20 shown can be used.

[0072] The connecting elements 20 may be evenly distributed over the height of the incision 9. Alternatively, an uneven distribution may also be advantageous, e.g. more connecting elements 20 being arranged near the base structure 3 than towards the paper side, or vice versa.

[0073] Figure 2 shows a fabric 1 according to an embodiment of the invention. In contrast to the fabric 1 shown in Figure 1, in this case the seam zone 2 of the laminated fibrous layer 8 is provided with bonding fibres that at least partially absorb light in the NIR wavelength range of 780 nm to 3 μm, which are bonded to one or more further laminated fibres by welding.

[0074] The seam zone 2 in this case extends over a predetermined section before and after the seam loop 4 and includes both a seam flap 10 and a seam wedge 11 .

[0075] In a preferred configuration, it may be envisaged that the seam zone 2 extends in the longitudinal direction of the fabric 1 over less than 100 mm, in particular over less than 50 mm, preferably over 30 mm. With such a short seam zone 2, the desired objective of stabilizing the laminated fibre layer 8 in the area of ​​the seam flap 10 and the seam wedge 11 is met. Moreover, a short seam zone is easily manufacturable. The connecting elements 20 shown in Fig. 1 are not provided in the configuration according to Fig. 2. However, in an alternative configuration according to another aspect of the invention, such connecting elements 20 may be provided.

[0076] The further laminated fibre layer 8b on the running side of the fabric 1 may also be omitted in alternative configurations of the invention.

[0077] Alternatively or additionally, a further laminated fibrous layer 8b may be disposed on the laminated fibrous layer 8 to provide the paper-contacting top surface of the fabric 1. Such a further laminated fibrous layer 8b typically does not have any binding fibers, or at least does not have any binding fibers that are bonded to one or more further laminated fibers by welding. However, it is also possible that the needling process causes individual binding fibers of the laminated fibrous layer 8 to penetrate completely or partially into the further laminated fibrous layer 8b, where individual welds to the further laminated fibers are created.

[0078] As shown in the range of illustrative examples, the laminated fibrous layer 8 containing bonding fibers may only be a part of the nonwoven support on the paper side of the felt 1, or even less than half of the nonwoven support on the paper side of the felt 1. [Explanation of symbols]

[0079] 1. Fabric 2. Seam Zone 3 Basic structure 4. Seam Loop 5 Plug-in Wires 6 Yarns in Machine Direction (MD) 7 Yarns in Cross Direction (CD) 8 Laminated fiber layer 8b Another laminated fiber layer 9 Cutting 10 Seam flap 11 Seam Wedge 15 Top surface in contact with paper 20 Connecting Elements

Claims

1. A seam felt for use in the press section of a machine for producing a fabric (1), in particular a fibrous web, comprising: The fabric (1) comprises at least one base structure (3) and at least one laminated fibrous layer (8) arranged on the base structure (3), the at least one laminated fibrous layer (8) being arranged on the side facing the fibrous web; The fabric (1) has at least one seam zone (2) in which seam loops (4) are joined to one another by at least one insert wire (5) to make the fabric (1) seamless; the at least one laminated fiber layer (8) is divided by at least one incision (9) in the region of the seam zone (2) to form a seam flap (10) and a seam wedge (11), the laminated fiber layer (8) comprises a predetermined amount of bonding fibers in both the seam flap (10) and the seam wedge (11) in the region of the seam zone (2), the bonding fibers being bonded to one or more other laminated fibers by welding, the bonding fibers of the seam flap (10) being bonded only to the laminated fibers of the seam flap (10), whereas the bonding fibers of the seam wedge (11) being bonded only to the laminated fibers of the seam wedge (11), and no bonding, particularly welding, is performed between the laminated fibers of the seam flap (10) and the laminated fibers of the seam wedge (11), The fabric (1) is characterized in that the area of ​​the seam zone (2) where the laminated fibers are joined by welding extends over less than 100 mm, in particular less than 50 mm, preferably 30 mm in the longitudinal direction of the fabric (1).

2. The fabric (1) according to claim 1, wherein the bonding fibers at least partially absorb light having wavelengths in the NIR range of 780 nm to 3 μm.

3. 3. The fabric (1) according to claim 1 or 2, wherein outside the seam zone (2), the proportion of bonding fibers in the laminated fibrous layer (8) is smaller than the proportion in the seam zone (2).

4. 4. The fabric (1) according to claim 3, wherein outside the seam zone (2), the laminated fibrous layer (8) is free of bonding fibers.

5. 3. The fabric (1) according to claim 1 or 2, wherein in the at least one laminated fiber layer (8), the proportion of bonding fibers in the seam zone (2) that at least partially absorb light in the NIR wavelength range of 780 nm to 3 μm is 5% to 40% by weight, in particular 15% to 30% by weight.

6. 3. The fabric (1) according to claim 1 or 2, wherein the binding fibers consist of the same polymer, in particular polyamide, as the other layer fibers, and / or the binding fibers are made at least partially absorbent for light with wavelengths in the NIR range of wavelengths between 780 nm and 3 μm by certain additives.

7. 3. The fabric (1) according to claim 1 or 2, wherein at least one further laminated fibrous layer (8b) is provided on the laminated fibrous layer (8) to provide a top surface of the fabric (1) that contacts the paper, the further laminated fibrous layer (8b) not containing bonding fibers.

8. A method for manufacturing a fabric (1) according to claim 1 or 2, comprising: a. preparing a base structure and making said base structure seamless by introducing interleaved wires (5) into seam loops (4) that are crossed over one another; b) placing a laminated fibrous layer (8) on the side of the base structure facing the fibrous web, the laminated fibrous layer (8) comprising a predetermined amount of bonding fibers in the area of ​​the seam loops (4), the bonding fibers preferably at least partially absorbing light of wavelengths in the NIR range of 780 nm to 3 μm; c) needling the laminated fibrous layer (8) onto the base structure (3); d. Welding the bonding fibers to the remaining laminated fibers to form a seam zone (2); e) cutting open the seam zone (2) to form seam flaps (10) and seam wedges (11), the area of ​​the seam zone (2) where the laminated fibres are welded together extending over less than 100 mm, in particular less than 50 mm, preferably 30 mm in the longitudinal direction of the fabric (1); A method comprising:

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