WOUND CLOTHING

Abstract

A clothing for a machine for producing a fibrous web, in particular a paper, board or tissue web, includes a first layer of first strips which are oriented parallel to one another, and a second layer of second strips which are oriented parallel to one another. The second layer is disposed on the first layer and is connected to the first layer. The adjacent first strips are spaced apart from one another and the adjacent second strips are also spaced apart from one another, so that a composite including the first layer and the second layer has a plurality of through openings for dewatering the fibrous web. A production method for producing a clothing of this type is also provided.

Claims

1-15. (canceled)

16. A clothing for a machine for producing a fibrous, paper, board or tissue web, the clothing comprising: a first layer of first strips oriented parallel and adjacent to one another, and a second layer of second strips oriented parallel and adjacent to one another, said second layer disposed on said first layer and connected to said first layer; said adjacent first strips being spaced apart from one another and said adjacent second strips being spaced apart from one another, forming a composite including said first layer and said second layer, said composite having a plurality of through openings for dewatering the fibrous web.

17. The clothing according to claim 16, wherein the clothing is a dryer fabric.

18. The clothing according to claim 17, wherein the dryer fabric is formed exclusively of said first layer and said second layer.

19. The clothing according to claim 16, wherein: said first strips are oriented at a first angle being greater than 0° and less than 90° relative to a cross-machine direction of the clothing; and said second strips are oriented at a second angle being greater than 90° and less than 180° relative to the cross-machine direction of the clothing.

20. The clothing according to claim 19, wherein said first angle lies between 45° and 80° relative to the cross-machine direction of the clothing, and said second angle lies between 100° and 135° relative to the cross-machine direction of the clothing.

21. The clothing according to claim 19, wherein said second angle corresponds to 180° minus said first angle.

22. The clothing according to claim 16, wherein said first strips have a substantially rectangular cross-sectional shape with a first thickness and a first width, and said second strips have a substantially rectangular cross-sectional shape with a second thickness and a second width.

23. The clothing according to claim 22, wherein said first thickness differs from said second thickness, and said thickness of said strips of one of said layers facing the fibrous web during an intended use is lower than said thickness of said strips of another of said layers facing away from the fibrous web during the intended use.

24. The clothing according to claim 22, wherein said first width corresponds substantially to said second width, and said first width and said second width have a value between 1 mm and 30 mm.

25. The clothing according to claim 22, wherein said first width corresponds substantially to said second width, and said first width and said second width have a value between 1 mm and 15 mm.

26. The clothing according to claim 16, wherein said through openings have a substantially rectangular or diamond shape.

27. The clothing according to claim 26, wherein all of said through openings have an identical shape.

28. The clothing according to claim 16, wherein said first strips and said second strips are connected integrally or welded to one another.

29. The clothing according to claim 16, wherein said first strips have a property absorbing radiation from a laser or NIR laser, and said second strips have a property differing from said property of said first strips.

30. The clothing according to claim 16, wherein at least one of said first strips or said second strips are formed either of: monoaxially stretched plastic or of biaxially stretched plastic, or a plastic provided with at least one of fillers or reinforcing fibers to increase strength.

31. The clothing according to claim 30, wherein said biaxially stretched film is cut into a shape of said strips.

32. The clothing according to claim 16, wherein at least one of said first strips or said second strips have perforations or laser-drilled perforations for increasing a permeability of the clothing.

33. The clothing according to claim 32, wherein said perforations or laser-drilled perforations are smaller than said through openings.

34. A method for producing the clothing according to claim 16, the method comprising: a) producing said first layer by winding said first strip helically over two rolls having mutually parallel longitudinal axes, and forming an interspace between windings of said first layer preventing side edges of said first strip from touching each other; b) producing said second layer on said the first layer by winding said second strip helically over the two rolls, and forming an interspace between windings of the second layer preventing side edges of said second strips from touching one another; and c) orienting said strips of said first and second layers to cross one another and to form a composite including said first layer and said second layer having a plurality of through openings for dewatering the fibrous web.

35. The method according to claim 34, which further comprises connecting said first layer integrally or by welding or by laser-welding to said second layer.

36. The method according to claim 35, which further comprises carrying out the step of connecting said first layer to said second layer during production of said second layer in step b) or as a separate step following step b).

37. The method according to claim 34, which further comprises subsequently at least one of re-treating, trimming or reinforcing side edges of the clothing.

Description

[0023] An exemplary embodiment of the clothing according to the invention and the production method according to the invention for such clothing will be described in more detail below with reference to FIGS. 1 to 3. In the drawing:

[0024] FIG. 1 shows a top view in the viewing direction orthogonal to the plane of the clothing of an imaginary detail of the same, which illustrates the structural design;

[0025] FIG. 2 shows a cross-sectional view of a first strip;

[0026] FIG. 3 shows a cross-sectional view of a second strip;

[0027] FIG. 4 shows a schematic view to illustrate the production method, wherein the production of the first layer by winding helically over two rolls is illustrated here; and

[0028] FIG. 5 shows a schematic view like FIG. 4 but from another viewing angle.

[0029] In FIG. 1, an imaginary detail of clothing 10 according to the invention, in particular a dryer fabric, is illustrated schematically, wherein the viewing direction is aligned orthogonally relative to the plane in which the clothing 10 lies. The machine direction MD of the clothing 10 points upward in FIG. 1 and extends in the vertical direction, whereas the cross-machine direction CD of the clothing 10 points to the right in FIG. 1 and is oriented in the horizontal direction. The clothing 10 is substantially formed from a first layer 12 which, during the intended use of the clothing 10 in the paper machine, can face away from the fibrous web, and a second layer 22, which is arranged on the first layer 12 and is firmly connected to the latter and which, during the intended use of the clothing 10 in the paper machine, can face the fibrous web. The first layer 12 comprises a plurality of first strips 14, which are all oriented parallel to one another, wherein immediately adjacent first strips 14 are spaced apart from one another, so that their side edges 16, 18 do not touch one another. Relative to the cross-machine direction CD, the first strips 14 are oriented at an angle α which, here, can be 70°, for example. The second layer 22 comprises a plurality of second strips 24, which are likewise all oriented parallel to one another, wherein immediately adjacent second strips 24 are spaced apart from one another so that their side edges 26, 28 do not touch one another. Relative to the cross-machine direction CD, the second strips 24 are oriented at an angle of 180°−α, here, therefore, at an angle of 180°−70°=110°, for example, so that the first strips 14 and the second strips 24 extend mirror-symmetrically relative to one another in relation to an imaginary plane aligned orthogonally to the plane of the image or fabric, which is oriented in the MD direction.

[0030] As can be seen in FIG. 2, the first strips 14 have a substantially rectangular cross-sectional shape, with a first thickness d1 and a first width b1. Likewise, the second strips 24 have a substantially rectangular cross-sectional shape, with a second thickness d2 and a second width b2, as can be seen in FIG. 3. In the present example, the first width b1, which, for example, can be 2.2 mm, corresponds to the second width b2. However, the first thickness d1, which, for example, can be 0.5 mm, is somewhat larger than the second thickness b2, which, for example, can be 0.3 mm. The first width b1 and the second width b2 are smaller than a spacing a between two adjacent first strips 14 and two adjacent second strips 24 (see FIG. 1). The gap or spacing a which thus results between two immediately adjacent strips 14, 24 of a corresponding layer 12, 22 can be 1 mm, for example.

[0031] In FIG. 1 it is possible to see clearly the diamond-shaped through openings 20 in the clothing 10 which are given by the two layers 12, 22. These through openings 20 are used to dry the fibrous web transported on the clothing 10. At the same time, during intended use, the clothing 10 according to the invention provides a large, largely flat, contact area both on the side facing away from the fibrous web and facing the drying cylinders and also the sides facing away from the fibrous web, which permits good heat transfer and thus efficient drying of the fibrous web.

[0032] The first strips 14 and the second strips 24 can be produced from a thermoplastic as monoaxially highly stretched monofilaments by means of an extrusion process, wherein the die of the extruder has a corresponding rectangular shape. Furthermore, the first strips 14 and the second strips 24 have been welded to one another at their respective crossing points, preferably with an NIR laser. To this end, the first strips 14 and/or the second strips 24 can have a laser light-absorbing property, in particular be colored black.

[0033] FIGS. 4 and 5 illustrate schematically from two different viewing angles a possible production process for the clothing 10 according to the invention, only the first layer 12 of the clothing 10 being shown in these two figures. Here, a first strip 14 is wound helically over two mutually spaced rolls 30, 32 having parallel longitudinal axes. The winding is carried out in such a way that the side edges 16, 18 of two immediately adjacent windings of the first strip 14 do not touch but have a spacing a from one another. Thus, even in the wrapped region of the two rolls 30, 32, their respective outer surface O can easily be seen.

[0034] Next, a second strip 24 would be wound helically over the two rolls 30, 32 and over the first strips 14 of the first layer 12 to form the second layer 22. The winding angle would be chosen such that the diamond-shaped through openings 20 illustrated in FIG. 1 would result. At the end, the side edges of the clothing 10 would be trimmed along the machine direction MD and reinforced to fix the free ends of the first strips 14 and the second strips 24. Optionally, the first strips 14 and/or the second strips 24 can additionally also be perforated, preferably by means of an appropriately powerful laser light source.

LIST OF DESIGNATIONS

[0035] 10 Clothing [0036] 12 First layer [0037] 14 First strip [0038] 16 Side edge [0039] 18 Side edge [0040] 20 Through opening [0041] 22 Second layer [0042] 24 Second strip [0043] 26 Side edge [0044] 28 Side edge [0045] 30 Roll [0046] 32 Roll [0047] α Angle [0048] CD Cross-machine direction [0049] b1 First width [0050] b2 Second width [0051] d1 First thickness [0052] d2 Second thickness [0053] MD Machine direction [0054] O Outer surface