PAPER MACHINE CLOTHING AND METHOD

Abstract

A paper machine clothing, in particular a press felt, for a machine for producing or processing a fibrous material web, includes a base structure and at least one layer of nonwoven fibers disposed on the base structure. The layer of nonwoven fibers has bonding fibers and further fibers. The bonding fibers and the further fibers differ in at least one material property, and at least some of the bonding fibers are connected to one or more further fibers and/or elements of the base structure by an integral joining connection, in particular a weld connection. A method for producing the clothing is also provided.

Claims

1-15. (canceled)

16. A clothing or press felt for a machine for producing or processing a fibrous material web, the clothing comprising: a base structure and at least one layer of nonwoven fibers disposed on said base structure; said at least one layer of nonwoven fibers including bonding fibers and further fibers; said bonding fibers and said further fibers differing in at least one material property; and at least some of said bonding fibers being connected by a weld connection to at least one of: one or more of said further fibers, or elements of said base structure.

17. The clothing according to claim 16, wherein said bonding fibers differ from said further fibers in that said bonding fibers substantially absorb NIR radiation in a wavelength range between 780 nm and 1100 nm, and said further fibers are entirely or substantially transparent for radiation in said wavelength range.

18. The clothing according to claim 16, which further comprises absorber additives disposed in or on said bonding fibers, said absorber additives absorbing NIR radiation in at least one wavelength range between 780 nm and 1100 nm.

19. The clothing according to claim 16, wherein said bonding fibers are provided in a proportion of less than 30 wt % of an entirety of said at least one layer of nonwoven fibers.

20. The clothing according to claim 19, wherein said proportion is less than 15 wt %.

21. The clothing according to claim 19, wherein said proportion is less than 8 wt %.

22. The clothing according to claim 16, wherein said bonding fibers are formed entirely or predominantly of a polymer material being identical to a polymer material forming said further fibers.

23. The clothing according to claim 16, wherein said bonding fibers are formed entirely or predominantly of a polymer material being different than a polymer material forming said further fibers.

24. The clothing according to claim 16, wherein said bonding fibers have a melting temperature being equal to or greater than a melting temperature of said further fibers.

25. The clothing according to claim 16, wherein said bonding fibers are formed entirely or predominantly of a polyamide, a copolyamide, a polyurethane or a polyether-block-polyamide copolymer (PEBA).

26. The clothing according to claim 16, wherein said further fibers include at least two types B1 and B2 of fibers, and said type B1 and type B2 fibers differ in at least one of titer or polymer material.

27. The clothing according to claim 16, wherein said at least one layer of nonwoven fibers is connected to said base structure by needling.

28. A method for producing a clothing or press felt for a machine for producing or processing a fibrous material web, the method comprising: a. placing a layer of nonwoven fibers on a base structure, the layer of nonwoven fibers including bonding fibers and further fibers differing in at least one material property; and b. forming material joining connections between the bonding fibers and the further fibers by controlled energy input.

29. The method according to claim 28, which further comprises providing the bonding fibers of the layer of nonwoven fibers as bonding fibers absorbing NIR radiation in an absorption wavelength range between 780 nm and 1100 nm, and carrying out the controlled energy input by irradiating in the absorption wavelength range.

30. The method according to claim 28, which further comprises carrying out the controlled energy input by irradiation from one side or from both sides of the layer of nonwoven fibers.

31. The method according to claim 28, which further comprises carrying out the irradiation along with a joining pressure acting onto the layer of nonwoven fibers.

32. The method according to claim 28, which further comprises: c. connecting the layer of nonwoven fibers to the base structure.

33. The method according to claim 28, which further comprises: c. connecting the layer of nonwoven fibers to the base structure by needling.

Description

[0062] The invention will be explained in more detail below with the aid of schematic figures, which are not true to scale.

[0063] FIG. 1 shows a detail of a clothing according to one aspect of the invention.

[0064] FIG. 2 shows a material joining connection according to a further aspect of the invention.

[0065] FIG. 1 schematically shows a small detail of a clothing according to one aspect of the invention. The clothing is in this case configured as a press felt. Here, the felt comprises a nonwoven layer 10 and a base structure 20, which is configured here as a base fabric 20. As an alternative, other base structures 20, for example a noncrimp or sheet structures, may however also be envisioned. The nonwoven layer 10 in this case comprises a number of bonding fibers 1 as well as further fibers 2. At a number of joining positions, the bonding fibers 1 are connected by means of material joining connections 4 to the further fibers 2. As shown by way of example in FIG. 1, the bonding fibers may also be connected to the base structure 20 by means of material joining connections 4. In FIG. 1, the joining connection 4 exists between a warp or weft thread of the woven base structure 20.

[0066] In some advantageous embodiments, the nonwoven layer 10 is furthermore also connected to the base fabric 20 by needling. This also leads to an additional mechanical connection of the nonwoven fibers to one another.

[0067] The felt shown in FIG. 1 comprises a nonwoven layer 10 only on one side, specifically on the paper side. As an alternative, a further nonwoven layer may be provided on the backing side. According to one aspect of the invention, this layer may be configured with or without bonding fibers.

[0068] The further fibers 2 of the nonwoven layer 10 may all be identical. Often, however, they will differ in properties such as the fiber diameter or titer, or sometimes also the polymer material used. In the example of FIG. 1, the bonding fibers 1 differ from the further fibers 2 in that they substantially absorb NIR radiation in a range between 780 nm and 1100 nm, while the further fibers are entirely or substantially transparent for radiation in this wavelength range. The material joining connections in the form of weld connections may thus be produced straightforwardly by means of NIR laser transmission welding.

[0069] FIG. 2 shows such a weld connection 4. In this case, a further fiber 2 is connected to a bonding fiber 1 by a weld connection. The bonding fiber 1 is in this case made of the same material as the further fiber 2, namely a polyamide. Using the same polymer material for both fibers 1, 2 has the advantage inter alia that the weld connection 4 is more homogeneous and more durable than when joining different materials. By addition of an absorber additive in the form of carbon black, the bonding fiber 1 has become substantially absorbent in the range between 780 nm and 1100 nm. In FIG. 2, the absorber additive was in this case added into the bonding fiber 1, which when using carbon black may be seen from the continuous black coloration. As an alternative, an absorber additive may also be provided only on the surface of the bonding fiber 1.

LIST OF REFERENCES

[0070] 1 bonding fiber [0071] 2 further fibers [0072] 3 base structure [0073] 4 material joining connections [0074] 10 nonwoven layer [0075] 20 base structure