EP2128335B1 - Method for manufacturing a felt sheet - Google Patents

Description

The invention relates to a method for producing a felt belt, in particular a press felt for a paper, board or Tissuemaschine.

Felt tapes, in particular press felts for paper, board or tissue machines, generally have a basic structure providing the dimensional stability of the felt, which is needled on both sides with one or more nonwoven fabric layers.

Press felts can be provided either as endless belts or as seams. Formed as endless belts press felts have in comparison to press felts with seam the disadvantage that they are often difficult to install in the paper machine, as they can not be drawn as an open band in the machine.

The basic structure of today known press felts is usually woven. Woven structures have the disadvantage that they are often very expensive to produce.

In the prior art, for example, press felts with nonwoven basic structures are already proposed, in which the basic structure comprises, for example, a longitudinal thread scrim. Such a basic structure formed by a Längsfadengelege is, for example, from the US 4,495,680 known. Most of the previously known Längsfadengelege comprehensive press felts are designed as endless belts.

From the EP1808527A1 Furthermore, a method is known, with which a seamable press felt can be produced with a Längsfadengelege. In practice, however, this method has in some cases the disadvantage that the structure in an intermediate stage of production lacks the necessary stability in the longitudinal direction of the thread, which makes handling in the production process more difficult.

It is the object of the present invention to propose a method for producing a seam-like structure comprising a longitudinal thread scrim which does not have the above-mentioned disadvantages.

The object is achieved by methods according to claims 1 and 2.

The idea of the invention is first of all to produce a helically wound longitudinal thread layer and only in a subsequent step to apply a transverse reinforcement structure to the longitudinal thread layer and to connect it to the longitudinal thread layer. This creates a hose-like composite structure. Subsequently, opposing sections of the produced tubular composite structure are superimposed so that the tubular composite structure forms a flat structure whose length corresponds approximately to half the circumference of the tubular structure and which at its opposite longitudinal ends seam seams provided by the at least one helically wound longitudinal thread are formed. Then the flat structure is made endless by bringing the opposite seam loops together and joining them together. Furthermore, the mutually deposited portions of the flat structure are connected together to form a basic structure.

According to an alternative aspect of the invention, a plurality of flat structures are produced, which are joined together to form an endless belt at the seam loops. This means that the successive flat structures together form an endless belt.

In both alternatives of the invention, a "continuous loop" forming Längsfadengelege is first created, which has the required tensile strength for subsequent handling. Due to the alternative embodiment, it is possible to construct basic structures for press felts of virtually any length from identically constructed modules.

The at least one thread is, for example, helically wound around two mutually spaced and substantially parallel rollers, the progress of the helical winding, i. the winding direction, perpendicular to the two rolls takes place. Here, the length of a winding corresponds to the circumference of the tubular composite structure.

Advantageous embodiments and further developments of the invention are specified in the subclaims.

To produce the longitudinal thread scrim, only a single longitudinal thread can be wound helically. However, it is also possible to wind a set of longitudinal threads helically to form the longitudinal yarn layer.

The one or more longitudinal thread or longitudinal threads forming the longitudinal thread loop is or are advantageously designed as monofilament thread or as monofilament threads. By providing a longitudinal thread scrim composed of one or more longitudinal threads or longitudinal threads whose suture loops are formed by monofilaments, a press felt which is particularly easy to stitch is provided.

A preferred embodiment of the method according to the invention provides that the endless or forming of an endless belt before connecting the successive filed sections. Because the basic structure is first made endless before the successive layers or sections of the tubular composite structure are connected to one another and their relative position is thus fixed relative to one another, it is possible, for example, to correct length inequality and tension in the flat structure. Preferably, for this purpose, the flat or flat structures are tensioned in their or their longitudinal direction after endless movement. This can be done, for example, by passing the endless flat sheet or ribbon over a pair of spaced-apart and mutually parallel rolls and increasing the distance between the rolls in the longitudinal direction of the flat sheet.

An alternative embodiment of the invention provides that the endless making or forming of an endless belt takes place after the connection of the sections deposited on one another.

The invention provides that at least one carrier ply is applied to the longitudinal thread ply after the production of the longitudinal thread ply and before the application of the transverse reinforcing structure. Alternatively, it is also conceivable that the carrier layer is applied to the Längsfadengelege together with the transverse reinforcement structure. In this case, for example, the transverse reinforcement structure is first connected to the carrier layer before this arrangement is applied to and connected to the longitudinal thread layer. This can be done, for example, to fix the distance between successive thread windings before applying the transverse reinforcement structure. In this case, the transverse reinforcement structure, for example, has no direct contact with the Längsfadengelege, but is connected to the Längsfadengelege on the support layer.

The invention provides that the Längsfadengelege and the transverse reinforcement structure are connected to each other via the carrier layer. This means that the carrier layer is preferably arranged between the transverse reinforcement structure and the Längsfadengelege.

Further, the carrier layer may be formed, for example, alone or in combination by a non-woven fabric layer or a film layer.

The carrier layer formed as a nonwoven fabric layer preferably comprises hot melt adhesive fibers. In this case, it is conceivable, in particular, for the longitudinal thread layer to be bonded to the nonwoven layer by melting and re-solidifying the hot-melt adhesive fibers, and / or for connecting the transverse reinforcement structure to the nonwoven layer by melting and re-solidifying the hot-melt adhesive fibers.

Before melting the hotmelt adhesive fibers of the nonwoven fabric layer or, alternatively, it is furthermore conceivable for the nonwoven fabric layer to be needled with the longitudinal yarn layer and / or with the transverse reinforcement structure. In this case, the longitudinal thread layer and / or the transverse reinforcement structure are preferably at least partially embedded in the nonwoven layer. This means that the connection between the scrim and the carrier layer and / or between the transverse reinforcing structure and the carrier layer can be done by needling and / or by fusing. Alternatively or additionally, bonding is also conceivable.

If the longitudinal thread layer and the transverse reinforcement structure are to be joined to the nonwoven layer comprising the melt adhesive fibers by melting and re-solidifying the melt adhesive fibers, it makes sense if the longitudinal thread layer, the transverse reinforcement structure and the fiber layer together are hot calendered together, for example by passing them together around a heated roller ,

The transverse reinforcement structure preferably comprises a transverse thread arrangement. In this case, the transverse thread arrangement can be formed, for example, alone or in combination by: a woven fabric, knitted fabric, knitted fabric, leno fabric or a Querfadengelege.

If the transverse thread arrangement is, for example, a woven or knitted fabric, then this may comprise transverse threads and, in relation thereto, thin longitudinal threads, by means of which the transverse threads are held in position. However, the transverse threads can also be held in position by a film or non-woven fabric layer on which the transverse threads are fixed.

For cost-effective production of the basic structure, it is conceivable in a variant not belonging to the invention, for example, that the transverse reinforcement structure is formed by a plurality of transverse reinforcement modules extending only over a portion of the length of the longitudinal yarn layer, one behind the other as viewed to form the transverse reinforcement structure in the longitudinal direction of the felt belt the Längsfadengelege be arranged.

In this case, the transverse reinforcement modules preferably extend on the width of the longitudinal thread fabric.

1. a) seitliches Zuführen der Querverstärkungsmodulausgangsbahn zum Längsfadengelege, d.h. quer zur Längsrichtung des Längsfadengeleges, und
2. b) flächiges Ablegen der zugeführten Querverstärkungsmodulausgangsbahn auf dem Längsfadengelege,
3. c) Trennen des auf dem Längsfadengelege abgelegten Abschnitts der Querverstärkungsmodulausgangsbahn von der übrigen Querverstärkungsmodulausgangsbahn zur Ausbildung eines Querverstärkungsmoduls,
4. d) Bewegen des Längsfadengeleges in seiner Längsrichtung relativ zur Querverstärkungsmodulausgangsbahn auf einer Strecke, die im Wesentlichen der Breite der Querverstärkungsmodulausgangsbahn entspricht,
5. e) Wiederholen der Schritte a) bis d) so dass die Querverstärkungsmodule in Längsrichtung des Filzbandes hintereinander liegend angeordnet sind.

Preferably, in this case, the transverse reinforcement modules are provided by a transverse reinforcement module exit track, so that the laying of the transverse reinforcement modules on the longitudinal thread cover can take place as follows:

1. a) lateral feeding of the transverse reinforcement module exit web to the Längsfadengelege, ie transverse to the longitudinal direction of the Längsfadengeleges, and
2. b) planar deposition of the supplied transverse reinforcement module exit track on the longitudinal thread cover,
3. c) separating the section of the transverse reinforcement module exit track deposited on the longitudinal thread layer from the remaining transverse reinforcement module exit track to form a transverse reinforcement module,
4. d) moving the longitudinal yarn layer in its longitudinal direction relative to the transverse reinforcement module exit web over a distance substantially equal to the width of the transverse reinforcement module exit web,
5. e) repeating the steps a) to d) so that the transverse reinforcement modules are arranged one behind the other in the longitudinal direction of the felt belt.

In this case, the method is preferably carried out in such a way that, in the finished basic structure, each of the transverse reinforcement modules deposited on the longitudinal thread layer extends along the width of the longitudinal thread layer and the transverse reinforcement modules arranged one behind the other complete the length of the longitudinal thread layer.

The production of the basic structure is cost-effective, in particular, if the transverse reinforcement module exit web is present as a roll product and this is unwound from the roll during the lateral feed.

For cost-effective production of the carrier layer, preferably a winding method is also used, so that a carrier layer extending over the entire width of the felt belt can be produced by helically winding a part-width carrier web. Accordingly, a preferred embodiment of the invention provides that the carrier layer is produced by winding a carrier web which extends only in part over the intended width of the felt belt in the direction of the intended width of the felt belt in a helical manner, in particular to the intended width of the felt belt ,

When helically winding the carrier web depending on the requirement, for example. Whether the carrier layer is to be formed one or more layers, facing edges of the same are placed on impact or overlapping regions.

After preparation of the basic structure, it is particularly advantageous for achieving high dimensional stability when it is subjected to tensile stress in the longitudinal thread direction and subjected to a heat treatment.

Preferably, the seam loops which are brought together or connected to one another are connected to one another by a pintle wire.

For the formation of the felt belt, it is also useful if the basic structure is needled on its upper side with at least one nonwoven fabric layer and / or on its underside with at least one nonwoven fabric layer. In this case, for example, the outer of the nonwoven layers needled onto the upper side of the basic structure provides the paper side of the felt belt. Further, for example, the outer of the nonwoven fabric pads needled on the underside of the base structure provides the machine side of the felt belt.

In order to achieve a good connection of the one or more nonwoven fabric layer (s) to the basic structure, according to a further preferred embodiment of the invention, it is provided that the transverse reinforcement structure preferably comprises multifilament threads. In this case, the multifilament threads can be twisted in particular. Preferably, the transverse threads of the transverse reinforcement structure are formed as multifilament threads. The above-mentioned embodiment is particularly advantageous when the longitudinal thread (s) of the longitudinal thread scrim are formed as monofilament threads or monofilament threads.

To influence the volume structure and / or the surface structure of the nonwoven fabric layers, it is useful if the at least one nonwoven fabric layer which is needled on the upper side and / or on the underside of the basic structure, particulate polymer material is introduced, which attaches to fibers of the nonwoven fabric layer and forms a porous composite structure with the same.

It is conceivable in this context, for example., That the particulate polymer material is melted after its introduction into the nonwoven fabric layer and after which again solidify together with the fibers of the nonwoven fabric layer forms the porous composite structure.

Figur 1

eine erste Ausführungsform eines erfindungsgemäßen Verfahrens,

Figur 2

eine zweite Ausführungsform eines erfindungsgemäßen Verfahrens,

Figur 3

eine Variante des Aufbringens und Verbindens einer Querverstärkungsstruktur auf einem Längsfadengelege.

The invention will be further elucidated on the basis of schematic drawings which are not to scale. Show it.

FIG. 1

a first embodiment of a method according to the invention,

FIG. 2

a second embodiment of a method according to the invention,

FIG. 3

a variant of applying and connecting a transverse reinforcement structure on a Längsfadengelege.

The FIG. 1 shows a first embodiment of a method according to the invention for producing a basic structure of a press felt.

The FIG. 1a shows the production of a longitudinal thread scrim 1 of the basic structure. For this purpose, a pair of mutually parallel threads 2 are wound helically around two mutually spaced and substantially mutually parallel rollers 3, 4, wherein the progress of the helical winding, ie the winding direction, perpendicular to the two rollers in the direction of the intended width (CMD) the felt belt is made to the intended width of the felt belt. The length of a winding corresponds to the circumference of the yarn layer 1 thus formed.

In the in the FIG. 1b illustrated process step is applied to the scrim 1 a trained as a nonwoven fabric carrier layer 5, which can be subsequently needled, for example, with the scrim. The nonwoven fabric layer 5 contains melt adhesive fibers and extends over the length and the width of the yarn layer 1.

The Indian Figure 1c Process status shown comprises the steps of applying a trained as Querfadengelege 6 transverse reinforcement structure on the already provided with the fiber layer 5 Längsfadengelege 1 and connecting the same with the Längsfadengelege 1 to form a tubular composite structure 7. In the present case, the compound of the transverse reinforcement structure 6 with the Längsfadengelege 1 on the Nonwoven fabric layer 5 mediates. For this purpose, the sandwich of longitudinal yarn layer 1, nonwoven fabric layer 5 and Querfadengelege 6 is first needled and then hot calendered between a heated pair of rollers 8,9, whereby the subsequent step Nonwoven fabric layer 5 with the longitudinal thread layer 1 and with the Querfadengelege 6 by melting and re-solidify the hot melt adhesive fibers is connected. The composite structure 10 thus obtained is tubular.

By needling it is achieved that the longitudinal thread layer 1 and / or the transverse thread layer 6 at least in sections, in particular completely, are embedded in the fiber fleece layer 5.

In the in the Figure 1d 1, 12 of the tube-like structure 10 are deposited on each other such that the tube-like structure 10 forms a flat structure 13 whose length corresponds approximately to half the circumference of the tube-like structure 10 and which at its opposite longitudinal ends 14, 15th Seam loops 16, 17 which are provided by the helically wound longitudinal thread 2.

The Figure 1e shows the process steps of the endless making of the flat structure 13 by merging the opposite seam loops 16, 17 and connecting them together by means of a pintle wire 18 and the joining of the superimposed portions 11, 12 of the flat structure 13 to form a basic structure 19. In the present case, the connecting takes place For example, by means of a needle assembly 20.

In the present case, the continuous operation takes place before joining the sections deposited on one another. For this purpose, the flat structure 13 is stretched after the endless in its longitudinal direction MD. In the present case, this is done by guiding the endless flat structure 13 over a pair of spaced-apart and mutually parallel rollers 21, 22 and increasing the distance between the rollers 21, 22 in the longitudinal direction MD.

The FIG. 2 shows a base structure 19 'which is formed by a plurality of juxtaposed flat structures 13a-13i, which are connected to each other by means of plug wires 18a-18i at their merged seam loops 16a, 17b.

The FIG. 3 shows a variant of applying and connecting a transverse reinforcement structure on a Längsfadengelege.

For this purpose, a Längsfadengelege 23 is provided with a length and a width. A nonwoven fabric layer 24 which extends along the length and width of the longitudinal yarn layer and which is needled with the longitudinal yarn layer 23 to form a longitudinal reinforcement module 33 is laid on the longitudinal yarn layer 23, so that the longitudinal yarn layer is arranged inside the fiber nonwoven layer 24. Furthermore, a transverse reinforcement module exit web 25 having a length and a width wound on a roll 26 and provided as a roll is provided. The transverse reinforcement module output track 25 is fed laterally to the longitudinal reinforcement module 33 by guiding the respective free end 27 of the transverse reinforcement module output track 25 from one longitudinal edge 28 of the longitudinal reinforcement module 33 to the other longitudinal edge 29 of the longitudinal reinforcement module 33 (see arrow). After or during feeding, the transverse reinforcement module exit track 25 is deposited on the longitudinal reinforcement module 33. After depositing, the portion of the transverse reinforcement module output track 25 deposited on the longitudinal reinforcement module 33 is separated from the remaining transverse reinforcement module output track 25 to form a transverse reinforcement module 30a, 30b.

Alternatively, already during the laying of the transverse reinforcement module exit runway 25 on the longitudinal reinforcement module 33, the section of the transverse reinforcement module exit runway 25 to be deposited on the longitudinal reinforcement module 33 can be separated from the remaining transverse reinforcement module exit runway 25 to form a transverse reinforcement module 30a, 30b. As from the representation of FIG. 3 can be seen, the transverse reinforcement modules 30a, Cut 30b so that its length corresponds to the width of the longitudinal reinforcement module 33.

In the presentation of the FIG. 3 A transverse reinforcement module 30a has already been deposited onto the nonwoven fabric layer 24 according to the method just described, while at the moment of presentation, the transverse reinforcement module exit strip 25 is fed laterally to the longitudinal reinforcement module 33 and deposited after being deposited (not shown) such that the transverse reinforcement module 30b extends on the width of the longitudinal reinforcement module 33.

After depositing a transverse reinforcement module 30a on the longitudinal reinforcement module 33, the longitudinal reinforcement module 33 has been moved in its longitudinal direction MD relative to the transverse reinforcement module exit track 25 for a distance that substantially corresponds to the width of the transverse reinforcement module exit track 25. By repeating the previously described steps, it is achieved that the transverse reinforcement modules 30a, 30b,... Are arranged one behind the other in the longitudinal direction of the felt belt.

In the present case, the method is carried out in such a way that, in the completed basic structure 31, each of the transverse reinforcement modules 30a, 30b extending on the longitudinal reinforcement module 33 extends along the width of the longitudinal reinforcement module 33, and the transverse reinforcement modules 30a, 30b arranged one behind the other join to another transverse reinforcement module (not shown) complete a continuous position.

The stored and cut cross reinforcing modules 30a, 30b, ... are joined to the nonwoven fabric layer 24 and the longitudinal yarn layer 23 by exposing the longitudinal yarn layer 23, the nonwoven fabric layer 24 and the cross reinforcing modules 30a, 30b, ... disposed thereon to heat Pressure be subjected by being passed around the heated roller 32. As a result, the transverse reinforcement modules 30a, 30b, the non-woven fabric layer 24 and the longitudinal yarn layer 23 pressed together, which ensures a good composite.

Claims (21)

1. Method for manufacturing a felt sheet, in particular a press felt for a paper machine, comprising the following steps:

   a) manufacturing a longitudinal scrim by means of progressive helical winding of at least one longitudinal thread in the direction of the envisaged width of the felt sheet, in particular as far as the envisaged width of the felt sheet,

   b) applying a carrier layer to the longitudinal scrim,

   c) applying a transverse reinforcing structure to the carrier layer arranged on the longitudinal scrim and joining the same to the longitudinal scrim via the carrier layer to form a tube-like composite structure, the transverse reinforcing structure extending over the entire length of the longitudinal scrim,

   d) laying opposite sections of the tube-like structure on one another in such a way that the tube-like structure forms a flat entity, the length of which corresponds approximately to half the circumference of the tube-like structure and which, at its opposite ends on the long sides, provides seam loops, which are formed by the at least one helically wound longitudinal thread,

   e) making the flat entity endless by leading together the opposite seam loops and joining the same to each other,

   f) joining the sections of the flat entity laid on one another to form a base structure.
2. Method for manufacturing a felt sheet, in particular a press felt for a paper machine, comprising the following steps:

   a) manufacturing a longitudinal scrim by means of progressive helical winding of at least one longitudinal thread in the direction of the envisaged width of the felt sheet, in particular as far as the envisaged width of the felt sheet,

   b) applying a carrier layer to the longitudinal scrim,

   c) applying a transverse reinforcing structure to the carrier layer arranged on the longitudinal scrim and joining the same to the longitudinal scrim via the carrier layer to form a tube-like composite structure, the transverse reinforcing structure extending over the entire length of the longitudinal scrim,

   d) laying opposite sections of the tube-like structure on one another in such a way that the tube-like structure forms a flat entity, the length of which corresponds approximately to half the circumference of the tube-like structure and which, at its opposite ends on the long sides, provides seam loops, which are formed by the at least one helically wound longitudinal thread,

   e) providing at least one further structure manufactured by using steps a) to d),

   f) forming an endless sheet by lining up the plurality of flat entities and joining them to one another at the seam loops,

   g) joining the sections of each of the flat entities respectively laid on one another to form a base structure formed from the plurality of tube-like structures.
3. Method according to either of Claims 1 and 2,
   characterized in that
   making a sheet endless or forming an endless sheet is carried out before the sections laid on one another are joined.
4. Method according to Claim 3,
   characterized in that
   the flat entity/entities is or are tensioned in the longitudinal direction thereof after being made endless.
5. Method according to either of Claims 1 and 2,
   characterized in that
   a sheet is made endless or an endless sheet is formed after the sections laid on one another have been joined.
6. Method according to one of the preceding claims,
   characterized in that
   the carrier layer is formed, on its own or in combination, by: a fibrous nonwoven layer, a film layer.
7. Method according to one of the preceding claims,
   characterized in that
   the transverse reinforcing structure comprises an arrangement of transverse threads.
8. Method according to Claim 7,
   characterized in that
   the arrangement of transverse threads is formed, on its own or in combination, by: a woven fabric, a knitted fabric, a crocheted fabric, a transverse scrim, a gauze fabric.
9. Method according to one of the preceding claims,
   characterized in that
   the transverse reinforcing structure is formed by a plurality of transverse reinforcing modules which extend only over part of the length of the longitudinal scrim and which, in order to form the transverse reinforcing structure, are arranged lying one behind another on the longitudinal scrim, as viewed in the longitudinal direction of the felt sheet.
10. Method according to one of the preceding Claims 6 to 9,
    characterized in that
    the longitudinal scrim is joined to the fibrous nonwoven layer by needling.
11. Method according to Claim 10,
    characterized in that
    the longitudinal scrim is embedded in the fibrous nonwoven layer.
12. Method according to one of the preceding Claims 6 to 11,
    characterized in that
    the fibrous nonwoven layer comprises fusible adhesive fibres and the fibrous nonwoven layer is joined to the longitudinal scrim by the fusible adhesive fibres being melted and solidified again.
13. Method according to Claim 12,
    characterized in that
    the transverse reinforcing structure is joined to the fibrous nonwoven layer by the fusible adhesive fibres being melted and solidified again.
14. Method according to one of the preceding claims,
    characterized in that
    the carrier layer is manufactured by a carrier web extending only over part of the envisaged width of the felt sheet being wound progressively helically in the direction of the envisaged width of the felt sheet as far as the envisaged width of the felt sheet.
15. Method according to Claim 14,
    characterized in that
    during the helical winding of the carrier web, edges of the same pointing towards one another are laid edge to edge or overlapping locally.
16. Method according to one of the preceding claims,
    characterized in that
    the base structure according to step f) is placed under tensile stress in the longitudinal thread direction and subjected to a heat treatment.
17. Method according to one of the preceding claims,
    characterized in that
    the seam loops that are brought together are joined to one another by a seam wire.
18. Method according to one of the preceding claims,
    characterized in that
    the base structure is needled with at least one fibrous nonwoven layer on its top side and/or with at least one fibrous nonwoven layer on its underside.
19. Method according to Claim 18,
    characterized in that
    particulate polymer material is introduced into the at least one fibrous nonwoven layer needled on the top side and/or on the underside of the base structure, is deposited on the fibres of the fibrous nonwoven layer and forms a porous composite structure with the same.
20. Method according to Claim 18 or 19,
    characterized in that
    the particulate polymer material is melted following its introduction into the fibrous nonwoven layer and, after it has been solidified again, forms the porous composite structure together with the fibres of the fibrous nonwoven layer.
21. Method according to one of the preceding claims,
    characterized in that
    the longitudinal scrim is formed from at least one monofilament thread, and in that the transverse reinforcing structure comprises multi-filament threads.

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