EP1837440B1 - Method for manufacturing a felt sheet and felt sheet - Google Patents

Description

The invention relates to a method for producing a felt with a carrier embedded in a fiber matrix of at least two superimposed yarn layers, of which at least one as Längfadengelege consisting of parallel longitudinal threads, and at least one as Querfadengelege consisting of parallel transverse threads are formed , wherein transverse threads are present, which are continuous across the width of the felt belt. The invention further relates to such a felt belt, in particular as a paper machine felt.

Especially in the field of papermaking belts, felt belts are known in which a carrier consisting of textile plastic threads is embedded in a fiber matrix of synthetic fibers. Such papermaking belts are used primarily as press felts in the press section of a paper machine. The preparation of the fiber matrix takes place in such a way that on the carrier one or more non-woven fabric layers are needled on one or both sides.

In the generic felt belt, the carrier is not made of a fabric, but of at least two superposed yarn layers. A scrim has at a distance from one another parallel arranged threads, which are not integrated with each other unlike fabrics and knitted fabrics. The filament scrims are arranged so that the threads of adjacent scrim intersect, and as a rule so that a scrim is formed as Längsfadengelege with extending in the longitudinal direction of the felt longitudinal filaments and a scrim as Querfadengelege transverse transverse threads.

Such a felt belt is in the form of an endless press felt in the US 4,781,967 disclosed. For the production of the felt belt first modules are formed, which consist either completely of a fiber layer or a combination of fiber layer and scrim. For the production of these modules is on the US 3,613,258 directed. The individual modules are then superposed and bonded together without the use of binding threads, in part using extruded polymeric material. How the connection of the individual modules creates an endless felt belt, is the US 4,781,967 not to be taken.

Due to the use of hot melt adhesive fibers or adhesive, the press felts are according to the US 4,781,967 relatively dense (cf. US Pat. No. 6,425,985 B1 , Column 1, lines 38 to 47) and stiff. This limits the usefulness of such felt belts in paper machines.

In the EP 1 359 251 A1 is also disclosed a carrier of at least two superposed yarn layers, wherein the carrier may also be covered with a fiber layer. The preparation of the carrier takes place in such a way that the longitudinal threads between two thread trees are clamped parallel to each other and then the transverse threads are placed over the longitudinal threads. Then, the transverse threads are fused with the longitudinal threads by means limited to their crossing points heating to melting temperature. The filaments can be heated by means of a laser beam if the filaments are provided by means of an additive which promotes the absorption of the laser beam.

Although in this process a very dimensionally stable carrier is obtained. Prerequisite, however, is that the longitudinal and transverse threads lie flat against each other, which requires a certain thread shape. This thread shape in turn counteracts the embedding of the carrier in a fiber matrix by needling nonwoven layers. Therefore, such carriers are only limitedly suitable for the production of press felts and are primarily for use in the dryer section of a paper machine and then determined without a fiber layer or fiber matrix.

In the EP 0 464 258 A1 a method for producing a felt belt is described, in particular as a press felt, in which the carrier is constructed in that a carrier web strip, the width of which is substantially smaller than the intended width of the carrier, helically wound on two spaced rollers until the intended Width of the carrier is reached. Simultaneously or subsequently, the carrier is covered with nonwoven strips in the same manner and the nonwoven web thus formed is needled to the carrier. The oblique side edges of a felt belt constructed in this way are then trimmed, resulting in straight side edges which extend in the running direction.

In this type of manufacture of the carrier, the longitudinal threads extend at an angle to the longitudinal direction of the felt belt due to the winding process, and there are no continuous transverse threads, so that the transverse strength of the felt is not very high. In order to obtain a better transverse strength, it has been proposed to join the edges of the carrier web strips together, for example by sewing ( US 5,360,656 ). When made of yarn-based carriers, the edges of the carrier web strip after the EP 0 947 623 A1 connected by the fact that the transverse threads of the Querfadengeleges interlock at the edges and there is a connecting thread placed on and welded to the intermeshing sections of the transverse threads. However, this has the disadvantage that in the region of the edges, a strip is formed, which due to the different arrangement and density of the threads other properties, in particular a lower permeability than the other surfaces of the felt belt. This can lead to marks on the paper web.

To remedy this is in the EP 1 209 283 A1 has been proposed to form the edges of the carrier web strip meandering with successive projections and recesses and the Trägerbahnstreifen to put together so that the projections and recesses interlock, wherein the projections completely fill the recesses. The connection of the edges is then done via connecting means, such as seams or adhesive tapes. However, this also results in changes in the properties of the finished felt in the area of the interlocking edges.

The invention has for its object to provide a method for producing a felt with a built-up longitudinal and transverse thread and embedded in a fiber matrix carrier with which a felt with high transverse strength in a simple and thus cost-effective manner and with the same properties over the width can be produced.

1. a) für jedes Längsfadengelege wird ein erstes Trägermodul wie folgt hergestellt:
   1. aa) es wird eine erste Hilfsträgerbahn in einer Breite hergestellt, die geringer ist als die Breite des fertigen Filzbandes;
   2. ab) die erste Hilfsträgerbahn wird mit Fäden zusammengebracht, welche die Eigenschaft haben, Laserenergie zu absorbieren und mittels Laserenergie zumindest oberflächlich und zumindest partiell auf Schmelztemperatur bringbar zu sein;
   3. ac) durch Einwirkung eines Laserstrahls werden die Fäden mit der ersten Hilfsträgerbahn verbunden;
   4. ad) die erste Hilfsträgerbahn wird vor, während oder nach dem Aufbringen der Fäden wendelförmig bis zu einer Breite gewickelt, die, gegebenenfalls nach Beschnitt der Seitenränder, der zur Herstellung des fertigen Filzbandes notwendigen Breite entspricht;
2. b) für jedes Querfadengelege wird ein zweites, das erste vollständig abdeckendes Trägermodul wie folgt hergestellt:
   1. ba) es werden zunächst einzelne Trägermodulabschnitte mit einer Erstreckung in einer Richtung hergestellt, die der zur Herstellung des fertigen Filzbandes notwendigen Breite entspricht;
   2. bb) die Trägermodulabschnitte bestehen jeweils aus der Kombination einer zweiten Hilfsträgerbahn und darauf befestigten Fäden, die die Eigenschaft haben, Laserenergie zu absorbieren und mittels Laserenergie zumindest oberflächlich und zumindest partiell auf Schmelztemperatur bringbar zu sein;
   3. bc) die Verbindung zwischen Hilfsträgerbahn und Fadengelege ist durch Einwirkung eines Laserstrahls auf die Fäden hergestellt worden;
   4. bd) zur Herstellung eines Trägerbandes werden die Trägermodulabschnitte auf das erste Trägermodul in dessen Längsrichtung hintereinander derart auf- und aneinander gesetzt, dass ein zweites Trägermodul mit Fäden entsteht, die sich quer zu den Fäden des ersten Trägermoduls erstrecken;
3. c) zur Herstellung des Filzbandes wird auf zumindest einer Seite der Trägermodule wenigstens eine Faservliesschicht unter Ausbildung der Fasermatrix aufgenadelt. Grundgedanke der Erfindung ist es also, den Träger dadurch herzustellen, dass für jedes Längsfadengelege ein endloses Trägermodul durch wendelförmiges Aufwickeln wenigstens einer Hilfsträgerbahn mit darauf vorher, währenddessen oder nachher aufgelaserten Längsfäden ein- oder mehrlagig angefertigt wird und dass auf dieses Trägermodul ebenfalls aus einer Hilfsträgerbahn und darauf aufgelaserten Fadengelege bestehende Trägermodulabschnitte ein- oder mehrlagig so aufgelegt werden, dass die Fäden in Querrichtung verlaufen, und dass schließlich eine Faservliesschicht zur Verbindung der Trägermodule und zur Ausbildung der Fasermatrix aufgenadelt wird. Dabei ist es nicht schädlich, wenn hierdurch die Hilfsträgerbahnen weitgehend zerstört werden, da sie lediglich dazu dienen, die Fäden während des Herstellungsvorgangs in den vorgesehenen Positionen zu halten. Dies übernimmt nach Aufnadeln der Faservliesschicht(en) die Fasermatrix.

This object is achieved according to the invention by a method having at least the following method steps:

1. a) for each longitudinal thread layer, a first carrier module is produced as follows:
   1. aa) a first auxiliary carrier web is produced in a width which is smaller than the width of the finished felt belt;
   2. ab) the first auxiliary carrier web is brought together with threads which have the property of absorbing laser energy and being able to be brought to melting temperature at least superficially and at least partially by means of laser energy;
   3. ac) by the action of a laser beam, the threads are connected to the first auxiliary carrier web;
   4. ad) the first auxiliary carrier web is wound helically, before, during or after the application of the threads, to a width which, if necessary after trimming of the side edges, corresponds to the width necessary for producing the finished felt strip;
2. b) for each transverse thread layer, a second, first completely covering, backing module is made as follows:
   1. ba) first individual carrier module sections are produced with an extension in one direction, which corresponds to the necessary for the production of the finished felt strip width;
   2. bb) the carrier module sections each consist of the combination of a second auxiliary carrier web and threads fastened thereon, which have the property of absorbing laser energy and being capable of being brought to melting temperature at least superficially and at least partially by means of laser energy;
   3. bc) the connection between the auxiliary carrier web and the scrim has been produced by the action of a laser beam on the threads;
   4. bd) for the production of a carrier tape, the carrier module sections on the first carrier module in the longitudinal direction one behind the other in such a way and put together that a second carrier module is formed with threads extending transversely to the threads of the first carrier module;
3. c) for the production of the felt belt at least one nonwoven layer is pinned on at least one side of the carrier modules to form the fiber matrix. The basic idea of the invention is therefore to produce the carrier in that, for each longitudinal thread layer, an endless carrier module is made by winding winding at least one auxiliary carrier web with longitudinal threads previously burned on it, subsequently or subsequently, and also on an auxiliary carrier web and onto this carrier module one or more layers are laid on it so that the threads run in the transverse direction, and that finally a non-woven fabric layer for the connection of the carrier modules and the formation of the fiber matrix is pinned. It is not detrimental if this causes the auxiliary carrier webs are largely destroyed, since they only serve to keep the threads during the manufacturing process in the intended positions. This takes over after needling the nonwoven layer (s) the fiber matrix.

With the aid of this method, felt tapes can be produced by taking advantage of the advantages of a winding process in a simple and cost-effective manner. Since they have continuous transverse threads, they have a high transverse strength. The felt tapes are also distinguished by the fact that their properties, in particular the water permeability which is important for use in a paper machine, are uniform over their area.

In an embodiment of the invention it is provided that threads are used which contain an additive which the Make filaments absorbent for the laser beam. Examples of such additives are NIR-active substances which are active in the near infrared and absorb, for example, in the wavelengths 808 nm, 940 nm, 980 nm or 1064 nm. For example, carbons or colorless additives such as Clearweld® from Gentex or Lumogen® IR from BASF are suitable for this purpose. The additive preferably extends over the entire length of the threads. In this case, the additive may be incorporated in the threads and / or applied to the surface of the threads. When the additive is incorporated, the weight fractions should be from 0.10% to 2.5%.

The auxiliary carrier webs may consist of a non-woven fabric and / or a plastic network, as for example from the EP 0 285 376 B . EP 0 307 182 A . WO 91/02642 or WO 92/17643 is known, and / or a film preferably made of plastic. As far as a nonwoven fabric is used, it should have a basis weight of 20 to 150 g / m ² , wherein for the application of the method according to the invention, a basis weight of 30 to 60 g / m ^{2 is} sufficient. The nonwoven fabric may also contain hot melt adhesive fibers.

Basically, the subcarrier webs should be made of a material that absorbs laser energy much less than the filaments or absorbs no laser energy. These are usually the usual thermoplastic materials, such as polyamide 4.6, 6, 6.6, 6.10, 6.12, 11, 12 and polyester, polypropylene, etc. Also, the threads themselves may be made of the aforementioned materials except for the additive, expediently from the same as that used for the auxiliary carrier webs. The same applies to the finally aufhnadelnde (s) Faservliesechieht (s), wherein in the case of several layers different fiber fineness can be provided, and preferably so that the finest Faserfeinheiten come to rest on the paper side surface of the felt.

According to the invention it is further provided that the threads are arranged parallel to the side edges of the auxiliary carrier webs, preferably at equal intervals. Due to the helical winding process of the first auxiliary carrier web, the longitudinal threads do not extend exactly in its longitudinal direction after completion of the felt belt, but rather slightly obliquely thereto.

Since the first carrier module is produced by means of a helical winding process, it is sufficient if the auxiliary carrier web used for the winding is produced in a width of 0.2 to 1.5 m. The second auxiliary carrier web expediently has an extension transverse to the applied or applied threads of 0.5 to 6 m, preferably 3 to 6 m. The production of the carrier module sections can be done in such a way that first an auxiliary carrier web of greater length produced and the threads are lasered and that then the thus formed band at intervals, which corresponds to the necessary for the production of the finished felt belt width of the felt belt is divided. The preparation of the second auxiliary carrier web can be carried out by means of the methods known in the art.

The felt belt is produced endlessly, since even the first carrier module is endless and the respective second carrier module from the carrier module sections is likewise assembled into an endless module.

In order to ensure that there is no displacement of filaments in the production process, the first auxiliary carrier web or the carrier module sections, preferably both, should be joined together at their adjacent edges. This can be done in different ways.

On the one hand, the edges can be overlapped and then joined together in the overlapping area. Conveniently, this is done so that one of the two edges in a width of 10 to 50 mm is not covered with threads and this edge is then brought to overlap with the adjacent, provided with threads edge. The connection of the two edges can then be done by welding by means of ultrasound or gluing. For this purpose, the threads themselves can be used by being applied again in the edge region with a laser beam. But the edges can also be sewn together. The thickening in the overlapping area is irrelevant because of the low thickness of the auxiliary carrier web, especially since it is largely destroyed during the later needling of the fiber fleece layer.

Thickening does not occur when the edges are butted together. In this case, the connection of the edges may be effected by providing the edges with successive complementary projections and recesses, and then placing the edges against one another so as to engage with their projections and recesses, and finally by protruding one against the other lying edges are joined together. In this case, the connection of the projections can take place in that over the projections at least one thread, preferably parallel to the other threads, runs and this at least one thread - it can also be several parallel threads - is connected to a part or all projections.

Procedurally, there are two alternatives available. In the first alternative, at least one thread is placed over the projections after the interlocking of the projections and recesses and then attached to them. Alternatively, however, it may be provided that even before the meshing of the projections and recesses - preferably with the laying and fastening of the remaining threads - at least one thread on the projections and recesses of at least one edge of the first Subcarrier and / or second auxiliary carrier web placed and secured to the projections and that after the intermeshing of the projections and recesses of the at least one thread is also attached to projections of the abutting edge. The attachment of the at least one thread prior to engagement may be limited to one of the two edges of the first and / or second auxiliary carrier web, but also on both edges, preferably symmetrically in such a way that the thread or the threads up to a half the width (transverse to the longitudinal direction) of the projections go.

The shape of the projections and recesses is relatively free. Examples are the EP 1 209 283 A1 refer to. Preferably, the projections should fill the recesses over the entire surface. The attachment of the at least one thread can be done in various ways, but preferably so that even for this purpose a laser energy-absorptive thread is taken and then it is attached by means of a laser beam to preferably all projections.

Conveniently, the threads running over the edges should correspond to the other threads, so be identical to them. Furthermore, the threads should be applied to the edges in a number and at a distance that after the meshing of the projections and recesses, the thread density in the region of the edges does not deviate from the thread density otherwise. Both measures serve to achieve uniform properties across the surface of the felt belt.

The invention furthermore relates to a felt belt which has been produced by means of the method according to the invention and accordingly has a carrier embedded in a fiber matrix of at least two yarn layers arranged one above the other, wherein transverse threads are present which are continuous across the width of the felt belt and wherein Threads have the property to absorb laser energy, so that they are at least superficially and at least partially brought to melting temperature by means of laser energy. According to the invention, the longitudinal threads extend at an angle to the longitudinal direction of the felt belt. This design makes it possible to produce the felt with the help of a winding process and consequently in a simple and cost-effective manner, without sacrificing the advantage of continuous transverse threads and thus high transverse strength. By embedding the carrier in a fiber matrix, it is not necessary to connect the longitudinal and the transverse threads with each other. It is enough just to superimpose them.

The oblique position of the longitudinal threads is achieved by the helical winding process during the production of the first longitudinal thread module and optionally further first longitudinal thread modules. It is also possible to wind the first auxiliary carrier sheet in multiple layers, preferably in such a way that the longitudinal threads under a cross very acute angle, suitably so that the angle to the longitudinal direction of the felt belt are equal in magnitude, the course of the longitudinal threads is mirrored so.

The property of being able to absorb laser energy can be obtained with the aid of the above-described additives. The threads may be formed as monofilaments, which also bicomponent threads come into question, in which then contains only one of the two components, the additive. Preferably, the bicomponent filaments should have a core and a surrounding sheath, the additive then being contained only in the sheath.

As an alternative to or in combination with monofilaments, the threads of at least one laid fabric can also be formed as multifilaments consisting of individual filaments. In this case, only a portion of the individual filaments needs to be provided with the additive, with a maximum proportion of 50% being sufficient. When exposed to the laser beam, the multifilaments stiffen due to the welding of the individual filaments also partially with each other.

But there are also monofilament threads from, for example, two to twelve monofilaments in question, although not all monofilaments need to be provided with additives here. It is sufficient if a maximum of 50% of such additives have. Here too, welding is the result the individual monofilaments with each other a stiffening of the threads.

According to the invention it is further provided that alternately different threads are used, for example, alternating monofilaments and multifilaments, monofilaments and threads or multifilaments and threads. But also the material can be used alternately, for example by alternating threads of polyamide 6 and 6.10 or alternating polyamide 6 and 6.12 or alternating polyamide 6.6 and polyester are used.

A useful felt tape is already created when only a longitudinal thread and a cross thread Gelgege are present. A higher strength is achieved if the carrier consists of at least two longitudinal thread located and at least one Querfadengelege. But it is also possible a reverse structure of a Längsfadengelege and two Querfadengelegen. For high structural requirements at least two Längsfadengelege and at least two Querfadengelege can be combined. In all cases, it is expedient if the longitudinal thread layer and the transverse thread layer alternate in each case.

The transverse threads need not extend exactly at right angles to the longitudinal direction of the felt belt. There is also the possibility that the transverse threads at an angle of 75 ° to 125 °, preferably 80 ° to 100 °, to the longitudinal direction run the felt tape. If the carrier has at least two Querfadengelege, it is possible to arrange the transverse threads so that the transverse threads of a Querfadengeleges and the transverse threads of the other Querfadengeleges intersect, preferably symmetrically, so that the transverse threads of a Querfadengeleges at the same angle from the vertical to the longitudinal direction of the felt belt deviate as the transverse threads of the other Querfadengeleges, only with the opposite sign.

The longitudinal threads and / or the transverse threads should have the same distance from each other over the surface to achieve uniform properties. It is expedient if the distance between the longitudinal threads and the distance of the transverse threads is the same. But it can also be different. Likewise, other threads can be used for the longitudinal threads than for the transverse threads, but also identical threads.

Figur 1

eine Draufsicht auf eine Vorrichtung zur Herstellung eines ersten Trägermoduls für das erfindungsgemäße Filzband;

Figur 2

eine Draufsicht auf einen Ausschnitt der Hilfsträgerbahn zur Herstellung des ersten Trägermoduls in vergrößerter Darstellung;

Figur 3

eine Draufsicht auf einen Ausschnitt des ersten Trägermoduls mit darauf aufgelegten Trägermodulabschnitten für die Herstellung des zweiten Trägermoduls;

Figur 4

einen Längsschnitt durch das erfindungsgemäße Filzband mit den ersten und zweiten Trägermodulen gemäß den Figuren 1 bis 3;

Figur 5

eine Draufsicht auf eine Modifikation des Trägers des Filzbandes gemäß Figur 4 ohne Fasermatrix;

Figur 6

eine Draufsicht auf einen Ausschnitt der Hilfsträgerbahn zur Herstellung des ersten Trägermoduls in vergrößerter Darstellung.

In the drawing, the invention is illustrated by means of exemplary embodiments. Show it:

FIG. 1

a plan view of an apparatus for producing a first carrier module for the felt tape according to the invention;

FIG. 2

a plan view of a section of the auxiliary carrier web for the production of the first carrier module in an enlarged view;

FIG. 3

a plan view of a section of the first carrier module with it placed on the carrier module sections for the production of the second carrier module;

FIG. 4

a longitudinal section through the felt according to the invention with the first and second carrier modules according to the FIGS. 1 to 3 ;

FIG. 5

a plan view of a modification of the carrier of the felt according to FIG. 4 without fiber matrix;

FIG. 6

a plan view of a section of the auxiliary carrier web for the production of the first carrier module in an enlarged view.

In the FIG. 1 shown device 1 has two spaced rollers 2, 3, which have parallel axes of rotation and are driven in the same direction. At a distance from the lower roll 2 is a supply roll 4, on which a nonwoven strip 5 low basis weight is wound. From the supply roll 4, the nonwoven strip 5 is withdrawn when driving the rollers 2, 3 and wikkelt on the two rollers 2, 3. In this case, the supply roll 4 is moved in the direction of the arrow A, that is parallel to the axes of rotation of the rollers 2, 3. In this way, the nonwoven strip 5 is helically progressing to the right wound on the rollers 2, 3. The feed of the supply roll 4 in the direction of arrow A is dimensioned so that the nonwoven strips 5 come to rest on each other. So that it does not come to tilting, the supply roll 4 is set correspondingly inclined. The winding process is continued until a nonwoven ribbon is produced by means of the nonwoven strip 5, whose width corresponds approximately to the width of the felt before thermosetting, which is to be produced by means of the nonwoven ribbon.

In the enlargement according to FIG. 2 are three partial webs 6, 7, 8 of the nonwoven strip 5 shown. It can be seen that the nonwoven strip 5 - and thus the partial webs 6, 7, 8 - on both longitudinal edges 9, 10 have complementary wave-shaped courses, so that alternately projections - by way of example denoted by 11 - and complementary recesses - exemplified by 12 - arise. In the partial webs 6, 7, the projections 11 and recesses 12 mesh with each other like a tooth, wherein the projections 11 fill the recesses 12 over the entire surface. The partial web 8 is shown spaced from the partial web 7. In fact, it enters the device 1 in such a way that the projections 11 engage in the recesses 12 in the same way as is the case with the adjacent edges 9, 10 of the partial webs 6, 7. Moreover, the left to the sub-web 6 subsequent sub-web is omitted.

How out FIG. 2 can also be seen (and in FIG. 1 not shown), are on the nonwoven strip 5 extending in the longitudinal direction extending longitudinal threads - exemplified by 13 - applied in parallel and at equal distances from each other, the longitudinal edges 9, 10, however, are left threadless. The longitudinal threads 13 are made of a thermoplastic and are provided with an additive that makes them absorbable for laser energy. The longitudinal threads 13 are selectively welded to the nonwoven strip 5 by the action of a transverse reciprocating laser beam. The connection can be made even before winding the Faservlieestreifens 5 on the supply roll 4 in a corresponding device. In this case, there is no pure nonwoven strip 5 on the supply roll 4, but a nonwoven strip 5 provided with longitudinal threads 13.

How out FIG. 2 can be seen, are on the longitudinal edges 9, 10 and the projections 11 three further longitudinal threads - exemplified by 14 - applied. They are identical to the longitudinal threads 13 and thus absorbent for laser energy. They are like the longitudinal threads 13 with a laser beam selectively heated to melting temperature and thereby connect with the projections 11. As a result, the edges 9, 10 and thus the partial webs 6, 7, 8 connected to each other. The longitudinal threads 14 on the longitudinal edges 9, 10 have the same distances from each other and to the adjacent longitudinal threads 13, so that the thread density in the region of the longitudinal edges 9, 10 corresponds to that in the remaining area.

In the example according to FIG. 2 However, it is not excluded that a reverse order is selected, that is, first the connection of the partial webs 6, 7, 8 by means of longitudinal threads 14 produced and then the remaining longitudinal threads 13 are applied. This can be done in each case in separate devices, which cause the laying of the longitudinal threads 13, 14 on the one hand and the fastening by means of a laser on the other. However, there is also the possibility to perform this in one operation, when this device between the rollers 2, 3 is arranged and at the same time the longitudinal threads 13, 14 are placed next to each other and fixed. In this case, however, it is necessary that the two rollers 2, 3 are moved counter to the direction of the arrow A and the supply roll 4 is held stationary.

FIG. 3 shows - in about the scale according to FIG. 1 , but significantly opposite FIG. 2 reduced - a first carrier module 16 fragmentary, which has been prepared by the helical winding process, as it turns out FIG. 1 results in continued until the intended width of the felt belt before thermosetting. On the still on the device 1 located carrier module 16 then support module sections 17, 16, 19 are placed. These carrier module sections 17, 18, 19 are constructed in the same way as the nonwoven strips 5, from which the first carrier module 16 has been produced. Each consists of a nonwoven web 20, 21, 22, are applied to the transverse threads - for example, each with 23, 24, 25 - applied. The transverse threads 23, 24, 25 are identical to the longitudinal threads 13, 14 of the carrier module 16 (in FIG. 3 omitted) and are therefore also in the same way by means of a laser beam to the nonwoven webs 20, 21, 22 attached. They each have the same distance from each other. The carrier module sections 17, 18, 19 are placed with the transverse threads 23, 24, 25 at the bottom on the first carrier module 16, so that the transverse threads 23, 24, 25 contact the longitudinal threads 13, 14 have.

The carrier module sections 17, 18, 19 have transverse edges 26 to 31, - which are left free of transverse threads 23, 24, 25. They are in the same manner as the longitudinal edges 9, 10 of the nonwoven strip 5 with successive projections - exemplified by 32 -, and with complementary recesses - exemplified by 33 - provided. At the upper transverse edge 27 of the lower carrier module section 17, the lower transverse edge 28 of the middle carrier module section 18 is set so that its projections 32 and recesses 33 engage in a tooth-like manner. About the protrusions 32 are three transverse threads - exemplified by 34 - placed and attached to them. About these transverse threads 34 are the two carrier module sections 17, 18 connected to each other. The attachment can also be done here by means of a laser beam.

Although the upper carrier module section 19 is placed on the first carrier module 16. For connection to the middle carrier module section 18, the upper carrier module section 19 must still be displaced towards the central carrier module section 18 in such a way that the projections 32 on the lower transverse edge 30 fit into the recesses 33 on the upper transverse edge 29 of the central carrier module section 18 in the same way between the carrier module sections 17, 18. Then also here three more transverse threads can be placed and connected to the projections 32. In this way, further carrier module sections are successively applied to the respectively preceding carrier module section and respectively connected thereto until the first carrier module 16 is completely covered by carrier module sections 17, 18, 19. The carrier module sections 17, 18, 19 then form a total of a second carrier module 35. In principle, any number of further first and second carrier modules can then be constructed in principle.

FIG. 4 shows the combination of the first carrier module 16 with the longitudinal threads 13 and the nonwoven strip 5 and the second carrier module 35, consisting of the Trägermododulabschnitten 17, 18, 19, which are connected to each other at the edge regions 36, 37 (here in deviation to FIG. 3 only two transverse threads 34 extend over the edge regions 36, 37). On the upper side of the second carrier module 35 and the lower side of the first carrier module 16 are non-woven fabric layers 38, 39. They are connected to the two carrier modules 16, 35 in that the in FIG. 4 shown unit of a needle machine is supplied. There, the fiber layers 38, 39 are compacted to form a fiber matrix and partially introduced into the spaces between the longitudinal and transverse threads 13, 14, 23, 24, 25, 34. In this case, the nonwoven strip 5 and the nonwoven webs 20, 21, 22 are largely destroyed. After leaving the needling machine and then thermofixing is an endless felt belt with a carrier 40, consisting of a Längsfadengelege 41 and a Querfadengelege 42, available, which can be used for example as press felt in a paper machine.

FIG. 5 shows a modified support 43 with a Längsfadengelege 44 and two Querfadengelegen 45, 46. The Längsfadengelege 44 consists of parallel spaced equally spaced longitudinal threads - exemplified by 47 - while the Querfadengelege 45, 46 respectively from parallel and spaced transverse threads are made. Of the transverse threads 48, 49, only a part is shown. The Querfadengelege 45 is disposed on the top and the Querfadengelege 46 on the underside of the Längsfadengeleges 44. The transverse threads 48 of the Querfadengeleges 45 are at a certain positive angle to the vertical on the longitudinal threads 47 obliquely. The transverse threads 49 of the Querfadengeleges 46 are set to the same amount, but negative angle to the vertical to the longitudinal threads 47 obliquely.

The Längsfadengelege 44 has been obtained by preparing a first carrier module in the manner described above. The Querfadengelege 45, 46 have been prepared by that corresponding carrier module sections on both sides of the first carrier module - or on one side of the carrier module and thus contiguous - have been applied and joined together. The production is carried out in the same manner as in the second support module 35 in the Ausfflhrungsungsform according to the FIGS. 1 to 4 , The obliquity of the transverse threads 48, 49 has been achieved in that the Triger module sections have been made rectangular before they have been placed obliquely on the first carrier module.

FIG. 6 represents an analog representation of FIG. 2 but the manufacturing process is different. The same reference numbers are used for the same parts.

As in the case according to FIG. 2 , Three partial webs 6, 7, 8 of the nonwoven strip 5 are partially shown. The partial webs 6, 7, 8 each have at both longitudinal edges 9, 10 complementary wavy projections 11 made of nonwoven fabric and complementary recesses 12. In the sub-webs 6, 7, the projections 11 and recesses 12 already engage each other like a tooth, while this is not the case with the sub-web 8 in relation to the sub-web 7.

On the nonwoven strip 5 and thus on the partial webs 6, 7, 8 extend in the longitudinal direction longitudinal threads - exemplified with 13 - parallel and at equal distances from each other. They are selectively welded to the nonwoven strip 5 by the action of a transverse reciprocating laser beam.

In contrast to the procedure in the embodiment according to FIG. 2 are - as shown in particular the part of web 8 - preferably together with the longitudinal threads 13 further longitudinal threads - exemplified by 14 - applied to the nonwoven strip 5, which extend over the projections 11 and recesses 12, on both longitudinal edges 9, 10. This Longitudinal threads 14 are welded to the projections 11 by the action of a laser beam in the same manner as the longitudinal threads 13 with the nonwoven strip 5. The longitudinal threads 14 have the same distances and extend parallel to each other and to the longitudinal threads 13. Only two longitudinal threads 14 are laid over the projections 11 and the recesses 12 so that more than half of the extension of the projections 12 remains free transversely to the extent of the longitudinal threads 13, 14.

The application of the longitudinal threads 13, 14 on the nonwoven strip 5 can be carried out before the winding of the provided with the longitudinal threads 13, 14 nonwoven strip 5 on the supply roll 4 in a corresponding device. However, there is also the possibility of the longitudinal threads 13, 14 applied only during or after unwinding of the nonwoven strip 5 from the supply roll 4 and then the sub-webs 6, 7, 8 adjoin one another such that the projections 11 engage in the recesses 12 like a toothing. As can be seen from the examples of the partial webs 6, 7, the longitudinal threads 14 complement each other by the complete engagement of the projections 11 and recesses 12 such that the thread density in this area is equal to the thread density of the longitudinal threads 13 in the remaining area and in this way uniform Längsfadengelege arises (the fact that the already juxtaposed partial webs 6, 7 in the region of the projections 11 and recesses 12 are covered only by three longitudinal threads 14, while on the projections 11 and recesses 12 of the two not contiguous partial webs 7, 8 in total four longitudinal threads 14 extend, based only on a graphical inaccuracy). After intermeshing the longitudinal threads 14 are connected at the longitudinal edge 9 with the projections 11 at the longitudinal edge 10 by the action of a laser beam. Conversely, the longitudinal threads 14 are also connected at the longitudinal edge 10 with the projections 11 at the adjacent longitudinal edge 9 by means of lasers.

The type of connection of the longitudinal edges 9, 10 described above can also in the connection of the carrier module sections 17, 18, 19 according to FIG. 3 be applied accordingly. The carrier module sections 17, 18, 19 are then not only provided with the transverse threads 23, 24, 25, but additionally - and applied simultaneously with the transverse threads 23, 24, 25 - with transverse threads 34, which extend over the projections 32 and recesses 33 , Only then are the carrier module sections 17, 18, 19 juxtaposed and, like the partial webs 6, 7, 8, connected to one another in the manner described above.

Claims (37)

1. A method for producing a felt sheet having a carrier (40, 43) embedded into a fibre matrix comprising at least two thread layers (41, 42, 44, 45) arranged one over the other, at least one of which is in the form of a longitudinal thread layer (41, 44) consisting of longitudinal threads (13, 14, 44) extending in parallel, and at least one of which is in the form of a transverse thread layer (42, 45, 46) consisting of transverse threads (23, 24, 25, 48, 49) extending in parallel, transverse threads (23, 24, 25, 48, 49) being provided which are continuous over the width of the felt sheet, characterised by at least the following procedural steps:

   a) for each longitudinal thread layer (41, 44) a first carrier module (16) is produced as follows:

   aa) a first auxiliary carrier sheet (5) is produced in a width which is smaller than the width of the finished felt sheet;

   ab) the first auxiliary carrier sheet (5) is brought together with threads (13, 14) which have the property of absorbing laser energy and, by means of laser energy, being able to be brought to melting temperature at least on the surface and at least partially;

   ac) by the effect of a laser beam the threads (13, 14) are connected to the first auxiliary carrier sheet (5) ;

   ad) the first auxiliary carrier sheet (5) is wound like a coil before, during or after applying the threads (13, 14), into a width which, optionally after trimming the side edges, corresponds to the width necessary for producing the finished felt sheet;

   b) for every transverse thread layer (42, 45, 46) a second carrier module (35), totally covering the first, is produced as follows:

   ba) individual carrier module sections (17, 18, 19) are initially produced with an extension in a direction which corresponds to the width necessary for the production of the finished felt sheet;

   bb) the carrier module sections (17, 18, 19) respectively consist of a combination of a second auxiliary carrier sheet (20, 21, 22) and threads (23, 24, 25, 48, 49) fastened to the latter which have the property of absorbing laser energy and being able to be brought, by means of laser energy, to melting temperature, at least on the surface and at least partially;

   bc) the connection between the second auxiliary carrier sheet (20, 21, 22) and the threads (23, 24, 25, 48, 49) has been produced by the effect of a laser beam upon the threads (23, 24, 25, 48, 49);

   bd) in order to produce a carrier sheet the carrier module sections (17, 18, 19) are placed on and against one another on the first carrier module (16) in the longitudinal direction of the latter such that a second carrier module (35) is produced with threads (23, 24, 25, 48, 49) which extend transversely to the threads (13, 14) of the first carrier module (16);

   c) in order to produce the felt sheet at least one fibre fleece layer (38, 39) is pinned onto at least one side of the carrier modules (16, 35) such as to form the fibre matrix.
2. The method according to Claim 1, characterised in that threads (13, 14, 23, 24, 25, 47, 48, 49) are used which contain an additive, and which enable the threads (13, 14, 23, 24, 25, 47, 48, 49) to absorb the laser beam.
3. The method according to Claim 1 or 2, characterised in that a fibre fleece and/or a network and/or a foil is used for the auxiliary carrier sheets (5, 20, 21, 22).
4. The method according to any of Claims 1 to 3, characterised in that fibre fleeces are produced with a mass per unit area of 20 to 150 g/m², preferably 30 to 60 g/m².
5. The method according to any of Claims 1 to 4, characterised in that the threads (13, 14, 23, 24, 25, 47, 48, 49) are arranged parallel to the parallel side edges of the auxiliary carrier sheets (5, 20, 21, 22).
6. The method according to any of Claims 1 to 5, characterised in that the first auxiliary carrier sheet (5) is produced in a width of 0.2 m to 1.5 m.
7. The method according to any of Claims 1 to 6, characterised in that the second auxiliary carrier sheets (20, 21, 22) are produced in an extension transverse to the threads of 0.5 to 6 m.
8. The method according to any of Claims 1 to 7, characterised in that the first auxiliary carrier sheet (5) and/or the carrier module sections (17, 18, 19) are connected to one another at their edges (9, 10, 26 to 31) lying against one another.
9. The method according to Claim 8, characterised in that the edges are overlapped and are connected to one another in the overlap region.
10. The method according to Claim 9, characterised in that the edges are stitched and/or welded and/or adhesively bonded to one another.
11. The method according to Claim 8, characterised in that the edges (9, 10, 26 to 31) are abutted against one another.
12. The method according to Claim 11, characterised in that the edges (9, 10, 26 to 31) are provided with consecutive, complementary projections (11, 32) and recesses (12, 33), and that the edges (9, 10, 26 to 31) are laid against one another so that they engage with one another with their projections (11, 32) and recesses (12, 33), and that projections (11, 32) of the edges (9, 10, 26 to 31) lying against one another are connected to one another.
13. The method according to Claim 12, characterised in that after the projections (11, 32) and recesses (12, 33) have engaged with one another at least one thread (14, 34) is laid over the projections (11,32) and is fastened to them.
14. The method according to Claim 12, characterised in that before the projections (11, 32) and recesses (12, 33) engage with one another, at least one thread is laid over the projections (11, 32) and recesses (12, 33) and is fastened to the projections (11, 32) at at least one edge (9, 10, 26 to 31), and that after the projections (11, 32) and recesses (12, 33) have engaged with one another the at least one thread (14, 34) is also fastened to the projections (11, 32) of the abutting edge (9, 10, 26 to 31).
15. The method according to Claim 14, characterised in that at least one thread (14, 34) is attached to the projections (11, 32) of both edges (9, 10, 26 to 31) of the auxiliary carrier sheets (5, 20, 21, 22).
16. The method according to any of Claims 12 to 15, characterised in that the threads (14, 34) extending over the edges (9, 10, 26 to 31) correspond to the other threads (13, 23, 24, 25, 47, 48, 49).
17. The method according to any of Claims 12 to 16, characterised in that the threads (14, 34) are applied to the projections in a number and at a distance such that after engaging with one another in the region of the edges (9, 10, 26 to 31) the thread density does not deviate from the normal thread density.
18. A felt sheet, in particular a paper machine felt, having a carrier (40, 43) embedded into a fibre matrix comprising at least two thread layers (41, 42, 44, 45, 46) arranged one over the other, at least one of which is in the form of a longitudinal thread layer (41, 44) consisting of longitudinal threads (13, 14 47) extending in parallel, and at least one of which is in the form of a transverse thread layer (42, 45, 46) consisting of transverse threads (23, 24, 25, 48, 49) extending in parallel, transverse threads (23, 24, 25, 48, 49) being provided which are continuous over the width of the felt sheet, and the threads (13, 14, 23, 24, 25, 47, 48, 49) having the property of absorbing laser energy and, by means of laser energy, being able to be brought to melting temperature by means of laser energy, at least on the surface and at least partially, characterised in that for every longitudinal thread layer (41, 44) a carrier module (16) is produced by coil-like winding of at least one auxiliary carrier sheet (5) with the longitudinal threads (13, 14, 47), so that the longitudinal threads (13, 14, 47) extend at an angle to the longitudinal direction of the felt sheet.
19. The felt sheet according to Claim 18, characterised in that the longitudinal and the transverse threads are only laid on top of one another.
20. The felt sheet according to Claim 18 or 19, characterised in that the threads (13, 14, 23, 24, 25, 47, 48, 49) contain an additive that makes them able to absorb laser energy.
21. The felt sheet according to any of Claims 18 to 20, characterised in that the threads (13, 14, 23, 24, 25, 47, 48, 49) of at least one thread layer (41, 42, 44, 45, 46) are in the form of monofilaments.
22. The felt sheet according to any of Claims 18 to 21, characterised in that the threads of at least one thread layer are in the form of multifilaments consisting of individual filaments.
23. The felt sheet according to any of Claims 18 to 22, characterised in that the threads of at least one thread layer are in the form of monofile yarns consisting of at least two monofilaments.
24. The felt sheet according to Claim 20 and Claim 21 or 22, characterised in that maximum one half of the individual filaments or monofilaments are provided with the additive.
25. The felt sheet according to any of Claims 18 to 24, characterised in that different threads are provided alternately.
26. The felt sheet according to Claim 25, characterised in that threads made, alternately, of polyamide 6 and 6.10 or threads made, alternately, of polyamide 6 and 6.12 or threads made, alternately, of polyamide 6.6 and polyester are provided.
27. The felt sheet according to Claim 25 or 26, characterised in that monofilaments and yarns alternately, yarns and multifilaments alternately, or monfilaments and multifilaments alternately are provided.
28. The felt sheet according to any of Claims 18 to 27, characterised in that the carrier consists of at least two longitudinal thread layers and at least one transverse thread layer.
29. The felt sheet according to any of Claims 18 to 27, characterised in that the carrier (43) is made of at least one longitudinal thread layer (44) and at least two transverse thread layers (45, 46).
30. The felt sheet according to any of Claims 18 to 28, characterised in that the carrier is made of at least two longitudinal thread layers and two transverse thread layers.
31. The felt sheet according to any of Claims 18 to 30, characterised in that longitudinal thread layers (44) and transverse thread layers (45, 46) alternate.
32. The felt sheet according to any of Claims 18 to 31, characterised in that the transverse threads (23, 24, 25, 48, 49) extend at an angle of 75° to 120°, preferably 80° to 100°, to the longitudinal direction of the felt sheet.
33. The felt sheet according to Claim 32, characterised in that the transverse threads (23, 24, 25, 48, 49) extend at an angle to the longitudinal direction of the felt sheet that is greater or smaller than 90°C.
34. The felt sheet according to any of Claims 18 to 33, characterised in that the carrier (43) has at least two transverse thread layers (45, 46) and the transverse threads (48) of the one transverse thread layer (45) and the transverse threads (49) of the other transverse thread layer (46) cross.
35. The felt sheet according to Claim 34, characterised in that the transverse threads (48) of the one transverse thread layer (45) deviate from the perpendicular to the longitudinal direction of the felt sheet by the same angle as the transverse threads (49) of the other transverse thread layer (46).
36. The felt sheet according to any of Claims 18 to 35, characterised in that the longitudinal threads (13, 14, 47) and/or the transverse threads (23, 24, 25, 48, 49) are spaced apart equally from one another.
37. The felt sheet according to Claim 36, characterised in that the distance between the longitudinal threads (13, 14, 47) and the distance between the transverse threads (23, 24, 25, 48, 49) is equal.

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