US20070000554A1

US20070000554A1 - Fabric Belt

Info

Publication number: US20070000554A1
Application number: US11/455,066
Authority: US
Inventors: Arved Westerkamp
Original assignee: Voith Paper Patent GmbH
Current assignee: Voith Patent GmbH
Priority date: 2005-06-17
Filing date: 2006-06-16
Publication date: 2007-01-04
Also published as: DE102005028254A1; EP1734176A2; EP1734176A3

Abstract

A fabric belt, in particular mesh belt, for a machine for producing a fibrous web, has warp threads extending generally parallel to the belt running direction and weft threads extending generally transversely with respect to the belt running direction, are connected to each other by crossing. The weave obtained by the arrangement of the warp and weft threads relative to one another on the running side of the fabric belt in the transverse direction and considered for at least one inserted running-side weft thread in each case is produced by a combination of at least two different float lengths. In addition, a process for producing such a fabric belt is disclosed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under German Patent Application 10 2005 028 254.7, filed 17 Jun. 2005, the disclosure of which is expressly incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The invention relates to a fabric belt, in particular mesh belt, for a machine for producing a fibrous web, having warp threads extending generally parallel to the belt running direction and weft threads extending generally transversely with respect to the belt running direction, which are connected to each other by crossing. This can be, in particular, a forming fabric. It also relates to a process for producing such a fabric belt.
2. Discussion of Background Information
With the development and provision of weaving machines having a shaft capacity of more than 26 weaving shafts, new technological possibilities have resulted in relation to the fabrication of forming fabrics and their properties.
In this case, the coverage of the entire range of possible weave variants in the forming fabric sector by means of the future use of this technology to its full extent is seen as an important objective.

SUMMARY OF THE INVENTION

The invention is an improved fabric belt and an improved process of making the improved fabric belt. Here, in particular, the higher shaft capacity of the weaving shafts that is in the meantime available is used for the purpose of covering the greatest possible number of possible weave variants.
With regard to the woven fabric, this is achieved in that the weave obtained by the arrangement of the warp and weft threads relative to one another on the running side of the fabric belt in the transverse direction and considered for at least one inserted running-side weft thread in each case is produced by a combination of at least two different float lengths.
Weave normally designates the pattern produced by the arrangement of the warp and weft threads relative to one another.
In this case, the different float lengths can be defined in particular by a different number of successively raised or successively lowered parallel warp threads in the transverse direction.
The different float lengths provided on the running side of the fabric belt are preferably in each case oriented toward the machine side.
According to one embodiment of the fabric belt according to the invention, a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is in each case produced only for one inserted running-side weft thread.
As an alternative to this, a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt can also be produced in each case for a pair of weft threads following each other in the belt running direction.
In another embodiment, a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt can be produced in each case for a thread arrangement formed by three threads of weft threads following each other in the belt running direction.
As an alternative to this, a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt can in particular also be produced in each case for a thread arrangement formed by four threads of weft threads following each other in the belt running direction.
A further alternative embodiment of the fabric belt according to the invention is distinguished by the fact that a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is produced in each case for a thread arrangement formed by five threads of weft threads following each other in the belt running direction.
According to a further alternative embodiment, a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is produced in each case for more than five weft threads following each other in the belt running direction.
It is also advantageous in particular if the pitch number of the running-side weft threads following each other in the belt running direction varies.
In a preferred embodiment of the fabric belt according to the invention, the float lengths on the running side of the fabric belt vary over the entire repeat. Repeat is to be understood to mean the pattern unit of the fabric which repeats in the same way in terms of width and length.
The float lengths from the running side of the fabric belt preferably vary over the entire repeat in such a way that, in the pattern of the goods, the result is an irregularly distributed running-side fabric diagonal.
In a preferred embodiment of the fabric belt according to the invention, the number of warp threads producing the weave of the overall fabric belt, that is to say the paper-side and running-side weave, and extending generally parallel to the belt running direction is greater than 26. In other words, the overall repeat of the fabric belt according to the invention is preferably greater than 26 warp threads. With the looms which are currently available with a higher shaft capacity (>26 weaving shafts), these warp threads, if necessary, can therefore be raised or lowered individually, which also means in particular that a corresponding number of possible combinations of different float lengths is made possible.
It is also understood that the number of warp threads producing the weave and extending generally parallel to the belt running direction can also be less than 26.
As already mentioned, the fabric belt can in particular be a forming fabric.
The process according to the invention for producing a fabric belt, in particular a mesh belt, for a machine for producing a fibrous web, having warp threads extending generally parallel to the belt running direction and weft threads extending generally transversely with respect to the web running direction, which are connected to each other by crossing, is distinguished by the fact that the weave obtained by the arrangement of the warp and weft threads relative to one another on the running side of the fabric belt in the transverse direction and considered for at least one inserted running-side weft thread in each case is produced by a combination of at least two different float lengths.
Preferred refinements of this process are specified in the subclaims.
With the invention, therefore, a type of running-side weave is specified in which the float lengths have different lengths. In this case, the different lengths can be distributed over different numbers of thread pairings and/or arrangements. On the running side of the fabric, float lengths oriented toward the machine side of the fabric are arranged in such a way that the float lengths vary in a manner distributed over the entire repeat. The result in the pattern of the goods is therefore a substantially irregular distributed running-side fabric diagonal, which results in the markings in the paper, which are brought about by pressure pulses on the running side of the fabric on the paper machine, becoming distinctly more diffuse, and therefore the look-through in the paper is improved.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention if further described in the detailed description which follows, in reference to the noted drawing by way of non-limiting example of exemplary embodiment of the present invention, and wherein:
FIG. 1 shows a schematic view of the running side of a forming fabric having equal float lengths distributed symmetrically over the repeat, and
FIG. 2 shows a schematic view of the running side of a forming fabric having partly different float lengths distributed asymmetrically over the repeat.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

The particulars shown herein are by way of example and for purposed of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.
FIGS. 1 and 2 each show a schematic view of the running side of a forming fabric 10 and 12, respectively, for a machine that produces a fibrous web, which can in particular be a paper or board web. The forming fabrics are in each case at least partly formed by a fabric belt, in which warp threads 14 and 16 extending generally parallel to the belt running direction L and weft threads 18 and 20 extending generally transversely with respect to the belt running direction L are connected to one another by crossing.
In this case, in the two views of FIGS. 1 and 2, the dark areas in each case represent warps being raised (warp over weft) and the light areas in each case represent warps being lowered (warp under weft) in the fabric. The warp runs from top to bottom, for example, and the weft runs from left to right, for example.
In the illustration according to FIG. 1, equal float lengths l are distributed symmetrically over the repeat, as a result of which clear diagonals 22 are formed.
By contrast, FIG. 2 shows in a schematic view the running side of a forming fabric 12 according to the invention, in which at least partly different float lengths l₁, l₂are distributed asymmetrically over the repeat. As can be seen from FIG. 2, the result in this case is broken diagonals 24.
In the preferred embodiment, the weave obtained by the arrangement of the warp and weft threads 16, 20 relative to one another on the running side of the forming fabric 12 formed by a fabric belt in the transverse direction and considered for one inserted running-side weft thread 20 in each case is produced by a combination of at least two different float lengths l₁, l₂. The different float lengths l₁, l₂can in particular be defined by a different number of successively raised or successively lowered parallel warp threads 16 in the transverse direction, in the present case the different float lengths l₁, l₂provided on the running side of the forming fabric 12 in each case being oriented toward the machine side.
The number of warp threads 16 producing the overall weave and extending generally parallel to the belt running direction L is preferably greater than 26. In principle, however, this number can also be less than 26.
It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.

LIST OF DESIGNATIONS

10 Fabric belt, forming fabric
12 Fabric belt, forming fabric
14 Warp threads
16 Warp threads
18 Weft threads
20 Weft threads
22 Diagonal
24 Diagonal
L Belt running direction
l Float length
l₁Float length
l₂Float length

Claims

1. A fabric belt for producing a fibrous web, comprising a plurality of warp threads extending generally parallel to a belt running direction and a plurality of weft threads extending generally transversely with respect to the belt running direction, the warp threads and weft threads connected to each other by crossing, wherein a weave obtained by the arrangement of the warp and weft threads relative to one another on a running side of the fabric belt in the transverse direction and for at least one inserted running-side weft thread is produced by a combination of at least two different float lengths.

2. The fabric belt of claim 1, wherein the at least two different float lengths are defined by at least one of a different number of successively raised and successively lowered parallel warp threads in the transverse direction.

3. The fabric belt of claim 1, wherein the different float lengths provided on the running side of the fabric belt are oriented toward the machine side.

4. The fabric belt of claim 1, wherein a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is produced only for one inserted running-side weft thread.

5. The fabric belt of claim 1, wherein a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is produced for a pair of weft threads following each other in the belt running direction.

6. The fabric belt of claim 1, wherein a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is produced for a thread arrangement formed by three threads of weft threads following each other in the belt running direction.

7. The fabric belt of claim 1, wherein a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is produced for a thread arrangement formed by four threads of weft threads following each other in the belt running direction.

8. The fabric belt of claim 1, wherein a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is produced for a thread arrangement formed by five threads of weft threads following each other in the belt running direction.

9. The fabric belt of claim 1, wherein a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is produced for more than five weft threads following each other in the belt running direction.

10. The fabric belt of claim 1, wherein a pitch number of the running-side weft threads following each other in the belt running direction varies.

11. The fabric belt of claim 1, wherein the float lengths on the running side of the fabric belt vary over an entire repeat.

12. The fabric belt of claim 11, wherein the float lengths on the running side of the fabric belt vary over the entire repeat in such a way that the result in the pattern of the goods is an irregularly distributed running-side fabric diagonal.

13. The fabric belt of claim 1, wherein the number of warp threads producing the weave and extending generally parallel to the belt running direction is greater than 26.

14. The fabric belt of claim 1, wherein the number of warp threads producing the weave and extending generally parallel to the belt running direction is less than 26.

15. The fabric belt of claim 1, wherein the fabric belt is a forming fabric (12).

16. A process for producing a fabric belt for a machine for producing a fibrous web, comprising warp threads extending generally parallel to a belt running direction and weft threads extending generally transversely with respect to a web running direction, the warp threads and the weft threads being connected to each other by crossing, wherein a weave obtained by the arrangement of the warp and weft threads relative to one another on a running side of the fabric belt in the transverse direction and for at least one inserted running-side weft thread in each case is produced by a combination of at least two different float lengths.

17. The process of claim 16, wherein, in order to produce the different float lengths, at least one of an appropriately different number of parallel warp threads following each other in the transverse direction are raised and an appropriately different number of parallel warp threads following each other in the transverse direction are lowered.

18. The process of claim 16, wherein the different float lengths provided on the running side of the fabric belt are in each case oriented toward the machine side.

19. The process of claim 16, wherein a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is in each case produced only for one inserted running-side weft thread.

20. The process of claim 16, wherein a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is in each case produced for a pair of weft threads following each other in the belt running direction.

21. The process of claim 16, wherein a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is in each case produced for a trio of weft threads following each other in the belt running direction.

22. The process of claim 16, wherein a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is in each case produced for a quartet of weft threads following each other in the belt running direction.

23. The process of claim 16, wherein a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is in each case produced for a quintet of weft threads following each other in the belt running direction.

24. The process of claim 16, wherein a respective relative arrangement of at least partly different float lengths obtained in the transverse direction on the running side of the fabric belt is in each case produced for more than five weft threads following each other in the belt running direction.

25. The process of claim 16, wherein a pitch number of the running-side weft threads following each other in the belt running direction is varied.

26. The process of claim 16, wherein the float lengths on a running side of the fabric belt are varied over an entire repeat.

27. The process of claim 26, wherein the float lengths on the running side of the fabric belt are varied over the entire repeat in such a way that the result in the pattern of the goods is an irregularly distributed running-side fabric diagonal.

28. The process of claim 16, wherein the number of warp threads producing the weave and extending generally parallel to the belt running direction is chosen to be greater than 26.

29. The process of claim 16, wherein the number of warp threads producing the weave and extending generally parallel to the belt running direction is chosen to be less than 26.

30. The process of claim 16, wherein the fabric belt formed is a forming fabric.