Abstract
A clothing for a machine for producing or processing a material web has a first and a second woven layer. The clothing has more first longitudinal threads than second longitudinal threads, but the number of first longitudinal threads is at most twice as large as the number of second longitudinal threads. Transverse threads of the second woven layer form contact floats on the machine contact side. Longitudinal threads of the first and second woven layer in each weaving repeat are arranged a first group and a second group. In the first group the longitudinal threads of the first and second layers are arranged precisely one above the other in the thickness direction of the clothing, while in the second group neither of two longitudinal threads of the first layer is arranged precisely above a single longitudinal thread of the second woven layer in the thickness direction of the clothing.
Claims
1-12. (canceled)
13. A clothing for a machine for producing or processing a material web, the clothing comprising: a first woven-fabric layer forming a web material contact side, said first woven-fabric layer being formed by interwoven first longitudinal threads that run in a clothing longitudinal direction and first transverse threads that run in a clothing cross direction; and a second woven-fabric layer forming a machine contact side, said second woven-fabric layer being formed by interwoven second longitudinal threads that run in the clothing longitudinal direction and second transverse threads that run in the clothing cross direction; said first woven-fabric layer and said second woven-fabric layer being connected to one another via binder threads; a number of first longitudinal threads in the clothing being greater than a number of second longitudinal threads, but being at most double the number of second longitudinal threads; and a weaving pattern of the clothing recurring in repeats, and the second transverse threads in each repeat forming at least two contact floats on the machine contact side, with all contact floats of the second transverse threads having a length of at most two; said first longitudinal threads and said second longitudinal threads in each repeat being disposed in a plurality of groups, with at least one first group and one second group, wherein the first group is formed of one first longitudinal thread and one second longitudinal thread that are disposed exactly on top of one another in a thickness direction of the clothing, while the second group is formed of two first longitudinal threads and one second longitudinal thread, and wherein none of the two first longitudinal threads of the second group is disposed exactly above the one second longitudinal thread of the second group in the thickness direction of the clothing.
14. The clothing according to claim 13, wherein said first longitudinal threads and said second longitudinal threads are dimensioned and disposed relative to one another in such a manner that, when viewed in a projection in the thickness direction of the clothing, said threads within a repeat form at least one free longitudinal strip.
15. The clothing according to claim 14, wherein the at least one free longitudinal strip is formed at all locations where different groups are disposed adjacent one another.
16. The clothing according to claim 13, wherein a number of said first groups differs from a number of said second groups in the clothing.
17. The clothing according to claim 13, wherein said second transverse threads form at most six contact floats on the machine contact side in each repeat.
18. The clothing according to claim 13, wherein the binding threads always run in pairs beside one another in the clothing cross direction, and said binding threads continue a weaving pattern on the web material contact side.
19. The clothing according to claim 18, wherein the binding threads continue the weaving pattern on the web material contact side in an alternating manner.
20. The clothing according to claim 13, wherein said first woven-fabric layer has a plain weave.
21. The clothing according to claim 13, wherein said first woven-fabric layer has a twill weave.
22. The clothing according to claim 21, wherein the twill weave of said first woven-fabric layer is a 2/1 twill weave.
23. The clothing according to claim 21, wherein the twill weave of said first woven-fabric layer is a 3/1 twill weave.
24. The clothing according to claim 21, wherein the twill weave of said first woven-fabric layer is a broken twill weave.
25. The clothing according to claim 21, wherein the twill weave of said first woven-fabric layer is a non-broken twill weave.
26. The clothing according to claim 13, wherein said second woven-fabric layer has a non-broken twill weave.
27. The clothing according to claim 13, wherein said second woven-fabric layer has a broken twill weave.
28. The clothing according to claim 13, wherein two neighboring contact floats of the second transverse thread are separated from one another by at most two second longitudinal threads.
29. The clothing according to claim 27, wherein two neighboring contact floats of the second transverse thread are in each case separated from one another by only one second longitudinal thread.
30. The clothing according to claim 13, being a forming screen for processing a tissue web.
31. The clothing according to claim 13 configured for producing a tissue web having a specific area weight between 8 g/m.sup.2 and 30 g/m.sup.2.
Description
[0028] Further advantageous features of the invention will be explained by means of exemplary embodiments with reference to the drawings, in which:
[0029] FIG. 1 shows a schematic illustration of a first embodiment of a clothing according to the invention in cross section, which has three contact flotations of a length of two, two and one per repeat;
[0030] FIG. 2 shows a schematic illustration of only the first and the second longitudinal threads of FIG. 1, which are disposed in groups;
[0031] FIG. 3a shows the weaving pattern of a first variant of the second layer of the woven fabric of FIG. 1, having a regular, non-interrupted twill weave;
[0032] FIG. 3b shows the weaving pattern of a second variant of the second layer of the woven fabric of FIG. 1, having an interrupted twill weave;
[0033] FIG. 4 shows the weaving pattern as in FIG. 3a, but with a somewhat different numbering;
[0034] FIG. 5 shows the complete weaving paths of all of the threads running in the clothing cross direction, including the binding threads, of the clothing according to the invention according to FIG. 4 within one repeat;
[0035] FIG. 6 shows the weaving pattern of the second layer of a second embodiment of the clothing according to the invention, which has four contact flotations per repeat, each having a length of one, having a plain weave;
[0036] FIG. 7 shows the complete weaving paths of all of the threads running in the clothing cross direction, including the binding threads, of the clothing according to the invention according to FIG. 6 within one repeat;
[0037] FIG. 8 shows the weaving pattern of the second layer of a third embodiment of the clothing according to the invention, which has four contact flotations having a length of two, one, two and one per repeat, having a regular, non-interrupted twill weave;
[0038] FIG. 9 shows the weaving pattern of the second layer of a fourth embodiment of the clothing according to the invention, which has four contact flotations having a length of two, two, two and one per repeat, having a regular, non-interrupted twill weave;
[0039] FIGS. 10a-b show the complete weaving paths of all of the threads running in the clothing cross direction, including the binding threads, of the clothing according to the invention according to a third embodiment; and
[0040] FIG. 11 shows the weaving pattern of only the second layer of the woven fabric of the third embodiment according to FIGS. 10a-b, having a regular, non-interrupted twill weave.
[0041] FIG. 1 in a schematic illustration shows a first embodiment of a clothing 10 according to the invention in cross section. The section plane shown here is defined by the clothing cross direction CD and the thickness direction T. This embodiment is distinguished in particular in that it has three contact flotations KF1, KF2 and KF3 per repeat, which have a length of two, two and one, respectively.
[0042] To be seen in FIG. 1 is a first woven-fabric layer L1 which provides a web contact side (at the top in FIG. 1), and a second woven-fabric layer L2 which provides a machine contact side disposed therebelow (at the bottom in FIG. 1). Both woven-fabric layers L1 and L2 are connected to one another by pairs of binding threads which extend substantially in the woven-fabric cross direction CD. The first woven-fabric layer L1 comprises first transverse threads QF1 which are interwoven with first longitudinal threads LF1. As is shown in FIG. 1, the first transverse threads QF1 can be mutually interwoven with the first longitudinal threads LF1 in a plain weave, so as to configure the first woven-fabric layer L1. Similarly, the second woven-fabric layer L2 comprises second transverse threads QF2 which are interwoven with second longitudinal threads LF2. The woven fabric 10 according to the invention here furthermore has the peculiarity that it comprises more first longitudinal threads LF1 than second longitudinal threads LF2, in this exemplary embodiment specifically 1.5 times as many first longitudinal threads LF1 as second longitudinal threads LF2. The first longitudinal threads LF1 as well as the first transverse threads QF1 have a noticeably smaller cross section than the second longitudinal threads LF2 and/or the second transverse threads QF2. In this way, a particularly fine and low-marking paper contact face of the first woven-fabric layer L1 can be provided, while the tensile loads which act on the clothing 10 in the intended use are primarily absorbed by the second woven-fabric layer L2.
[0043] The second transverse threads QF2 on the machine contact side (at the bottom in FIG. 1) of the clothing 10 have flotations, specifically so-called contact flotations KF1, KF2 and KF3, all of which are kept short, i.e. only guided below a second longitudinal thread or at most below two longitudinal threads disposed directly next to one another. This has an advantageous effect on the transverse stability of the clothing 10. The thickness of the clothing 10 in the region of the contact flotations KF1, KF2 and KF3 is reduced in comparison to the clothing with longer contact flotations known from WO 2008/068317 A1.
[0044] FIG. 2, in a schematic illustration, shows only the first longitudinal threads LF1 and the second longitudinal threads LF2 from FIG. 1 per repeat, but not the various transverse threads. It is highlighted by this illustration that the first longitudinal threads LF1 and the second longitudinal threads LF2 in each repeat are disposed in a plurality of groups G1 and G2, specifically at least one first group G1 and one second group G2, wherein the first group G1 is formed from one first longitudinal thread LF1 and one second longitudinal thread LF2 which are disposed exactly on top of one another in the thickness direction T of the clothing 10, while the second group G2 is formed from two first longitudinal threads LF1 and one second longitudinal thread LF2, wherein none of the two first longitudinal threads LF1 of the second group G2 is disposed exactly above the one second longitudinal thread LF2 of the second group G2 in the thickness direction T of the clothing 10. In the present exemplary embodiment, the two groups G1 and G2 continually alternate with one another. The first longitudinal threads LF1 and the second longitudinal threads LF2 here are dimensioned and disposed relative to one another in such a manner that, when viewed projected in the thickness direction T of the clothing 10, said threads within a repeat form at least one free longitudinal strip, wherein such a strip is preferably formed at all locations where different groups G1, G2 are adjacent to one another. The free longitudinal strips facilitate the de-watering of the material web on the material contact side (at the top in FIG. 1) toward the machine contact side (at the bottom in FIG. 1), this being illustrated by arrows in dashed lines in FIG. 2. The term free longitudinal strip consciously does not take into account that the transverse threads, not shown in FIG. 2, may impede the free de-watering, or at least in portions in the longitudinal direction of the clothing 10 (orthogonal to the image plane in FIG. 1 or 2) obstructs rectilinear de-watering in the thickness direction T of the clothing 10, from the web contact side of the clothing 10 to the machine contact side of the clothing 10.
[0045] FIGS. 3a and 3b show two different variants of the weaving pattern of the second layer L2 of the clothing 10 from FIGS. 1 and 2. The columns of this chessboard-like illustration of the weaving pattern correspond to the second longitudinal threads LF2, whereas the lines correspond to the second transverse threads QF2. Where an x is marked in the box, the corresponding second transverse thread QF2 at the top, i.e. toward the web contact side of the clothing 10, is guided over a corresponding second longitudinal thread LF2. Conversely, where there is no x in the box, or the box is empty, the corresponding second transverse thread QF2 is guided below the corresponding second longitudinal thread LF2, thus forming a contact flotation KF1, KF2 or KF3 on the machine contact side of the clothing 10. Shown once again below the weaving pattern, for the purpose of visualization, is the profile of the weaving path of a second transverse thread QF2, specifically of that second transverse thread denoted as number 1 in the weaving pattern illustrated thereabove.
[0046] The two variants shown in FIGS. 3a and 3b differ from one another in that the second layer L2 in the first variant according to FIG. 3a has a regular, non-interrupted twill weave, whereas the second layer L2 in the second variant according to FIG. 3b has an interrupted twill weave. The rib of the respective twill weave is indicated by a diagonally running dashed line in FIGS. 3a and 3b. In the second variant according to FIG. 3b, the 12 second transverse threads QF2 of the repeat can be subdivided into 4 groups, or portions, of identical size, wherein each group, or each portion, per se again has a regular, non-interrupted twill weave.
[0047] FIGS. 4 and 5 show once again in more detail the weaving pattern of the first variant according to FIG. 3a, wherein in more detail here means that the weaving paths of all threads in one repeat of the clothing 10 are illustrated in FIG. 5, thus also the weaving paths of the first longitudinal threads LF1 and the first transverse threads QF1 of the first layer L1, and the weaving paths of the binding threads connecting the two layers L1 and L2. Accordingly, there is a different numbering of the second longitudinal threads LF2 and second transverse threads QF2 of the second layer L2 in FIG. 4 in comparison to FIG. 3a, whereby FIG. 4 otherwise corresponds to FIG. 3a. Each second pair of threads extending substantially in the cross direction in FIG. 5 is a pair of binding threads, wherein illustrated by a dotted line in each case is one binding thread of the pair of binding threads. The binding threads, conjointly with the first transverse threads QF1 and the first longitudinal threads LF1, form a plain weave on the web material contact side.
[0048] FIG. 4 shows that the second woven-fabric layer L2, in the case of the first variant of the first embodiment too, is a multi-rib twill, because there are two twill ribs of dissimilar widths.
[0049] FIGS. 6 and 7 show the weaving paths of a second embodiment of the clothing according to the invention. The latter differs from the first embodiment primarily in that the second layer has four contact flotations per repeat, wherein each individual contact flotation has a length of one. In this way, the second layer has a plain weave. The type of illustration of the second embodiment corresponds to that of FIGS. 4 and 5 for the first embodiment, respectively.
[0050] Two further embodiments of the clothing according to the invention are illustrated in FIGS. 8 and 9, wherein the illustration corresponds to that in FIGS. 3a and 3b, because only the weaving pattern of the second layer per repeat is also shown here. The third embodiment according to FIG. 8 is distinguished in that there are four contact flotations per repeat, which have a length of two, one, two and one. In contrast, the fourth embodiment according to FIG. 9 is distinguished in that there are only three contact flotations which have in each case a length of two. The second woven-fabric layer, in the third as well as the fourth embodiment, has in each case a regular, non-interrupted multi-rib twill weave.
[0051] FIGS. 10a, 10b and 11 describe a third, particularly preferred embodiment of the present invention. FIGS. 10a and 10b show the entire profile of the first transverse threads QF1, the second transverse threads QF2 and the binding threads relative to the first longitudinal threads LF1 and the second longitudinal threads LF2 in two complete repeats of the clothing 10. In FIGS. 10a and 10b, the first transverse threads QF1, the second transverse threads QF2 and the binding threads, which all extend in the cross direction of the clothing, are denoted as Weft 1 to Weft 40, whereas the first longitudinal threads LF1 and the second longitudinal threads are simply numbered using the numerals 1 through 26. As can be gathered from these figures, a complete repeat thus comprises eight first longitudinal threads LF1, specifically the longitudinal threads numbered 1, 3, 4, 6, 8, 9, 11 and 13, whereas the longitudinal threads numbered 14, 16, 17, 19, 21, 22, 24 and 26 only represent a first repetition, and five second longitudinal threads LF2, specifically the longitudinal threads numbered 2, 5, 7, 10 and 12, whereas the longitudinal threads numbered 15, 18, 20, 23 and 25 only represent a first repetition. In this way, the ratio of first longitudinal threads LF1 to second longitudinal threads LF2 is 8:5. This differentiates the third embodiment from the first two embodiments, in which this ratio was 3:2. In this way, particularly fine surfaces can be formed on the web material contact side.
[0052] In a manner similar to what has been described in the context of the first embodiment in FIG. 4, FIG. 11 shows only the weaving pattern of the second woven-fabric layer L2, illustrated twice next to one another. In the present third exemplary embodiment, each second transverse thread QF2 of a complete repeat of the second layer L2 has in each case two contact flotations, specifically one of the length 1, and one of the length 2. By way of example, a specific weaving path is illustrated once again at the bottom in FIG. 11, specifically that from the second transverse thread QF2 numbered 2, according to the uppermost line in the chessboard-like illustration thereabove.
[0053] As can furthermore be gathered from FIG. 11, the second layer L2 has a regular, non-interrupted twill weave, wherein the widths of the ribs differ from one another, however. This is therefore a multi-rib twill here too.
LIST OF REFERENCE SIGNS
[0054] 10 Clothing [0055] CD Clothing cross direction [0056] G1 First group [0057] G2 Second group [0058] KF1 First contact flotation [0059] KF2 Second contact flotation [0060] KF3 Third contact flotation [0061] L1 First layer [0062] L2 Second layer [0063] LF1 First longitudinal thread [0064] LF2 Second longitudinal thread [0065] QF1 First transverse thread [0066] QF2 Second transverse thread [0067] T Thickness direction
