WEB CONNECTION AND PAPER MACHINE FABRIC

Abstract

A web connection for a fabric of a machine for producing or processing a fibrous material web includes a first web end with first longitudinal thread ends, a second web end with second longitudinal thread ends, and at least one connection element which extends in the transverse direction of the resultant fabric. The connection element has an upper face and a lower face, and the first longitudinal thread ends and the second longitudinal thread ends solely contact and bond to the upper face of the connection element, in particular the thread ends are welded thereto. The fabric with a paper side and a running side. The fabric has at least one first web layer with at least one such web connection which is arranged such that the lower face of the at least one connection element is oriented in the direction of the running side of the fabric.

Claims

1-9. (canceled)

10. A woven fabric connection for a clothing of a machine for producing or processing a fibrous web, the woven fabric connection comprising: a first woven fabric end having first longitudinal thread ends and a second woven fabric end having second longitudinal thread ends, and at least one connecting element which extends in a transverse direction of the clothing to be formed; said at least one connecting element having an upper side and a lower side; said first longitudinal thread ends and said second longitudinal thread ends being in contact exclusively with said upper side of said at least one connecting element; and said first longitudinal thread ends and said second longitudinal thread ends being connected in a materially integral manner to said upper side of said at least one connecting element.

11. The woven fabric connection according to claim 10, wherein said first and second longitudinal thread ends are welded to said upper side.

12. The woven fabric connection according to claim 10, wherein said at least one connecting element is one of a plurality of connecting elements, and said first and second longitudinal thread ends are in each case in contact exclusively with said upper side of said connecting elements and are connected in the materially integral manner to said connecting elements.

13. The woven fabric connection according to claim 12, wherein said plurality of connecting elements are two or three connecting elements.

14. The woven fabric connection according to claim 12, wherein all of said connecting elements are threads.

15. The woven fabric connection according to claim 10, wherein said at least one connecting element is a thread.

16. The woven fabric connection according to claim 10, wherein a diameter of said at least one connecting element is larger than a diameter of the interwoven transverse threads of said first woven fabric end and of said second woven fabric end.

17. The woven fabric connection according to claim 16, wherein the diameter of said at least one connecting element is greater by more than 10% than the diameter of the interwoven transverse threads of the first woven fabric end and of the second woven fabric end.

18. The woven fabric connection according to claim 16, wherein the diameter of said at least one connecting element is greater by more than 30% than the diameter of the interwoven transverse threads of the first woven fabric end and of the second woven fabric end.

19. A clothing for a machine for producing or processing a fibrous web, the clothing comprising: a web-contacting paper side and a running side facing away from the web to be produced or processed; at least one first woven fabric tier having at least one woven fabric connection according to claim 10; said at least one woven fabric connection being disposed with the lower side of the at least one connecting element being oriented in the direction of said running side of the clothing.

20. The clothing according to claim 19, wherein said first woven fabric tier has a plurality of said woven fabric connections, and wherein all of said woven fabric connections are disposed with the lower side of the respective said connecting elements being oriented in the direction of said running side of the clothing.

21. The clothing according to claim 19, further comprising at least one or a plurality of further woven fabric tiers which likewise have a respective said woven fabric connection, wherein the first woven fabric tier is disposed closer to the paper side of the clothing than the further woven fabric tiers.

22. The clothing according to claim 19, further comprising at least one further woven fabric tier being a circular-woven fabric tier.

23. The clothing according to claim 19, wherein the clothing is a press felt and the paper side of the clothing is a non-woven tier which is connected to said first woven fabric tier by needle-punching.

24. A seam clothing for a machine for producing or processing a fibrous web, the clothing comprising: a web-contacting paper side and a running side facing away from the web; a basic structure formed by a woven fabric piece being folded at two fold locations and deposited onto itself to configure a two-tier woven fabric; said woven fabric piece having two woven fabric ends connected to one another by a woven fabric connection according to claim 10; wherein seam loops are formed at the fold locations and wherein an endless woven fabric loop is generated by connecting the seam loops by a pintle element to form a pintle seam; said woven fabric connection being disposed such that the lower side of the at least one connecting element is facing in the direction of an interior of the two-tier woven fabric.

25. The seam clothing according to claim 24, wherein said woven fabric connection is disposed in that tier of the two-tier woven fabric that is closer to the paper side of the clothing, and wherein a lower side of the connecting element is oriented in a direction of the running side of the clothing.

26. The seam clothing according to claim 24, wherein said woven fabric connection is disposed in that tier of the two-tier woven fabric that is closer to the running side, and wherein the lower side of the connecting element is oriented in a direction of the paper side of the clothing.

Description

[0080] The invention will be explained in further detail hereunder by means of schematic figures in which:

[0081] FIGS. 1a and 1 b explain a woven fabric connection according to one aspect of the present invention;

[0082] FIG. 2 shows a woven fabric connection according to a further aspect of the invention;

[0083] FIGS. 3a to 3d show cross sections of potential connecting elements according to various aspects of the invention;

[0084] FIG. 4 shows further potential cross sections for connecting elements according to various aspects of the invention;

[0085] FIG. 5 shows a clothing according to a further aspect of the invention;

[0086] FIGS. 6a and 6b each show a clothing according to a further aspect of the invention; and

[0087] FIGS. 7a to 7e show a potential production process for a woven basic structure for a clothing, in particular according to one aspect of the present invention.

[0088] FIG. 1a shows a first woven fabric end 2a and a second woven fabric end 2b, which are to be connected by means of a woven fabric connection 1. This here can be, for example, two ends of a single woven fabric piece which is rendered endless by the woven fabric connection. However, this can also be woven fabric ends 2a, 2b of two different woven fabric pieces, which are joined by the woven fabric connection 1.

[0089] The first woven fabric end 2a here has first longitudinal thread ends 3a, and the second woven fabric end 2b here has second longitudinal thread ends 3b. In order to generate longitudinal thread ends 3a, 3b of sufficient length for the woven fabric connection 1, some transverse threads 6 of the non-depleted woven fabric have been removed at the two woven fabric ends 2a, 2b. It is often advantageous for between two and five transverse threads 6 to be removed per woven fabric end 2a, 2b.

[0090] It is shown in FIG. 1b how the two woven fabric ends 2a, 2b from FIG. 1a are combined. Provided here are three connecting elements 4 in the form of connecting threads 4 which run in the transverse direction of the subsequent clothing.

[0091] The connecting elements 4 here have an upper side 4a and a lower side. The first longitudinal thread ends 3a and the second longitudinal thread ends 3b are disposed such that said longitudinal thread ends 3a, 3b are in contact exclusively with the upper sides 4a of the connecting elements 4. For producing the woven fabric connection 1, the connecting elements 4 are connected in a materially integral manner to the upper sides 4a of the connecting elements 4. The materially integral connection can advantageously be generated by welding, in particular by (laser) transmission welding. If the longitudinal thread ends 3a, 3b are from a polyamide, as is customary in many clothings, said longitudinal thread ends 3a, 3b are entirely or largely transparent to light in the NIR range. If at least the upper side 4a of the connecting elements 4 is designed to be absorbent to light from this range, for example by adding a suitable absorber additive such as carbon blackthe longitudinal thread ends 3a, 3b can be radiated with a suitable NIR laser light, the absorbent upper sides 4a of the connecting elements 4 being heated and welded to the longitudinal thread ends 3a, 3b. The process is usually carried out by applying a specific joining pressure.

[0092] Alternatively however, the material integral connection can also, for example, be implemented by other welding methods such as ultrasonic welding, or adhesively bonded connections.

[0093] The woven fabric connection 1 shown in FIG. 2 is a special embodiment of the woven fabric connection 1 from FIG. 1b. The connecting elements 4 here are embodied in the form of connecting threads 4 which have a larger diameter in comparison to transverse threads 6 in the non-depleted woven fabric of the woven fabric ends 2a, 2b. This leads to more stable welded connections, the reason for the latter being that the contact pressure force applied when welding the woven fabric ends 2a, 2b better presses the longitudinal thread ends 3a, 3b and the connecting elements 4 into one another in the connecting region, and generally larger contact areas on the thread connections are generated. Nevertheless, woven fabric connections 1 having only minimal deviations in terms of the thickness in comparison to the non-depleted woven fabric are obtained by simultaneously compressing and welding.

[0094] In this way, woven fabric connections 1 having connecting elements 4 with diameters of 0.5 mm instead of 0.4 mm for the transverse threads 6 of the non-depleted woven fabric, and strengths increased by 30-90%, can be obtained, for example. However, the thickness of the connecting zone 1 was comparable in both cases and largely identical to the thickness of the non-depleted woven fabric.

[0095] Another example is a 1.5-tier or 2-tier woven fabric in which, for example, the threads running in the transverse direction lie next to one another so densely that said threads as a result are slightly disposed upward and downward, as a result of which a thicker and more voluminous woven fabric is created. As a result, in the case of transverse threads 6 and longitudinal threads of the longitudinal thread ends 3a, 3b with a diameter of in each case, for example, 0.4 mm, the woven fabric per se can have a thickness of 1.2 mm, for example. (The diameters stated are to be understood only as exemplary potential values. The invention is however not limited to these values). If threads with a diameter of 0.4 mm were likewise to be used as connecting elements 4 here, the thickness of the woven fabric connection, being about 0.8 mm, would be significantly less than that of the remaining woven fabric. This can lead inter alia to undesirable marks in the paper produced.

[0096] A solution here can also lie in the use of thicker connecting elements 4. In the case of a diameter of the connecting elements of 0.8 mm, conjointly with the diameter of the longitudinal thread ends 3a, 3b of 0.4 mm, this results in 1.2 mm and thus the same thickness for the woven fabric connection as for the woven fabric. As has been described above, the diameter of the connecting elements 6 may even be slightly (e.g. 10% or 20%) more. As a result of simultaneous compressing and welding, woven fabric connections 1 having only minimal deviations in terms of the thickness in comparison to the non-depleted woven fabric are also obtained again.

[0097] While woven fabric connections 1 having the desired thicknesses can be generated as a result, it may however arise on occasions that the woven fabric connection 1 thus created, as a result of the comparatively thick connecting elements 4, is quite heavy, or else hard, and especially also quite non-compressible, in comparison to the non-depleted woven fabric. This can be alleviated in that the connecting elements 4 by a suitable choice of the material (e.g. while using an elastomer), and/or by suitable shaping of the cross sections thereof, are provided with a certain elasticity. Examples to this end are advantageously shown in FIGS. 3a-3d and 4.

[0098] Moreover, the connecting elements 4 in FIG. 2 have been inserted at a spacing which is larger than the spacing of the transverse threads 6 in the non-depleted woven fabric of the woven fabric end 2a, 2b. In order for the longitudinal thread ends 3a, 3b to be generated here, four transverse threads 6 at the woven fabric ends 2a, 2b have been in each case removed in an exemplary manner, but only 3 transverse threads have been inserted as connecting elements 4 for the woven fabric connection 4. As a result, somewhat more open woven fabric connections 1 which have a reduced material density are received upon connecting.

[0099] Moreover, the connecting region 1 which is relatively rigid per se (all longitudinal thread ends 3a, 3b and all connecting elements 4 are ideally welded to one another at all contact points) is somewhat more flexible. Both effects have an advantageous effect, for example when needle-punching the woven ground fabric tiers to fibrous non-woven tiers of a press felt.

[0100] In order to be able to carry out the material integral connection efficiently by means of laser transmission welding, it is advantageous for the connecting elements 4 at least on the upper side 4a thereof to be embodied so as to be absorbent. As has already been described above, to this end the entire connecting element can be embodied so as to be absorbent by means of an absorber additive. However, it is also possible for only parts of the connecting element 4 to be absorbent. FIG. 3a shows a classic core/casing thread in which only the casing 8 is absorbent while there is a relatively large degree of freedom in the design of the core 7. This core can again be from a polyamide, for example. However, it is also possible for the core 7 to be made from other materials, for example an elastomer polyurethane. The elastic properties of the connecting element 4, which are increased as a result, can prove advantageous.

[0101] FIGS. 3b, 3c, and 3d show variants of these connecting elements 4 from mixed materials.

[0102] To be seen in FIGS. 3b and 3c are half-and-half threads 4, once having a round cross section, and once having a rectangular cross section. The upper part, for example the upper half, here is from an absorbent casing material 8, and the lower part is from a non-absorbent core material 7.

[0103] FIG. 3d shows a variant of FIG. 3c. In the case of a rectangular connecting element 4 here, only the surface of the upper side 4a is from an absorbent material 8. The latter can be applied to the connecting element prior to welding, for example. Suitable materials are commercially available under the trade name Clearweld, for example.

[0104] The connecting elements 4 shown here are intended only to demonstrate the diversity of possibilities. The invention is not limited to these examples.

[0105] FIG. 4 shows further potential cross sections for the connecting elements 4 according to various aspects of the invention. The compressibility and elasticity can be varied also in the case of threads from a single material by way of suitable shaping, for example in the shape of an X, a Y, or a wedge. Moreover, the contact area of the connecting elements having the longitudinal thread ends can be increased without generating an excess of material density in the woven fabric connection.

[0106] Alternatively however, connecting elements 4 shaped in such a manner as shown in FIG. 4 can have a core 7 which is surrounded by an absorbent casing material 8.

[0107] FIG. 5 shows a clothing 10 according to a further aspect of the invention. The clothing 10 is embodied as a press felt. Said clothing 10 comprises a non-woven tier 13 which makes available the paper side 11 of the clothing 10. The non-woven tier 13 is disposed on a first woven fabric tier 14 and fastened by needle-punching, for example. The first woven fabric tier 14 here has a woven fabric connection 1 which connects a first woven fabric end 2a having first longitudinal thread ends 3a and a second woven fabric end 2b having second longitudinal thread ends 3b to one another. Provided to this end in the clothing 10 of FIG. 5 are three connecting elements 4 which extend in the transverse direction of the clothing 10. The connecting elements 4 here are materially connected, in particular welded, to the first longitudinal thread ends 3a and the second longitudinal thread ends 3b exclusively by way of the upper side 5 of said connecting elements 4.

[0108] The woven fabric connection 1 is disposed such that the lower side 5b of the connecting elements 4 is oriented in the direction of the running side 12 of the clothing 10. This arrangement of the woven fabric connection 1 influences the marking tendency of the press felt 10. The, optionally overlapping, longitudinal thread ends 3a, 3b point toward the paper side 13, and the transversely disposed threads of the connecting elements 4 point toward the running side 12. As a result of the relatively densely packed longitudinal threads 3a, 3b (approx. double the threaded density in the connecting region 1), potential mechanical marks emanating from the connecting elements 4 are minimized. This is all the more important because the transverse threads of the connecting elements 4 in advantageous embodiments have a larger mutual spacing than the transverse threads 6 in the non-depleted woven fabric.

[0109] Examples of clothings 10 according to further aspect of the present invention are also shown in FIGS. 6a and 6b. As opposed to FIG. 5 however, the clothings 10 shown here, or additionally to the first woven fabric tier 14, have in each case one further woven fabric tier 15, wherein the first woven fabric tier 14 is disposed closer to the paper side 11 of the clothing 10 than the further woven fabric tiers 15. The further woven fabric tiers 15 in these illustrations likewise have at least one woven fabric connection 1 according to one aspect of the present idea. In the clothings 10 shown in FIGS. 6a and 6b, these woven fabric connections 1 are disposed substantially on top of one another. However, it can frequently be advantageous for the woven fabric connections 1 of the first woven fabric tier 14 and the woven fabric connections 1 of the further woven fabric tier 15 not to be disposed directly on top of one another but to be mutually offset in the machine longitudinal direction (MD) and to have an MD spacing of more than 10 cm or more than 100 cm, for example.

[0110] The difference between FIG. 6a and FIG. 6b lies in the orientation of the woven fabric connection 1 in the further woven fabric tier 15. In the clothing 10 of FIG. 6a the woven fabric connection 1 is oriented like the first woven fabric tier 14. The longitudinal thread ends 3a, 3b point toward the paper side 13, and the transversely disposed threads of the connecting elements 4 point toward the running side 12. In contrast, in the clothing 10 of FIG. 6b the woven fabric connection 1 is oriented exactly the opposite way. Such an arrangement of the woven fabric connections 1 can in many cases be favorable from the point of view of production technology. In this way, the woven fabric connection 1 of the further woven fabric tier 15 can be closed simply by transmission welding, for example, in that the connecting region is irradiated with laser light from the running side, for example. This light can then penetrate the usually transparent longitudinal thread ends 3a, 3b and is absorbed by the upper sides 5 of the connecting elements, as a result of which the materially integral connection is generated. In the embodiment as in FIG. 6 this is not possible because the energy would be absorbed by the lower sides 5b of the connecting elements 6. Welding of the upper sides 5 to the longitudinal thread ends 3a, 3b is thus impossible.

[0111] FIGS. 7a to 7e show a potential production process for a woven basic structure for a clothing 10, in particular for a clothing 10 according to one aspect of the present invention.

[0112] A woven fabric piece in the process is folded at two fold locations 20 and deposited onto itself such that the two woven fabric ends 2a, 2b touch or overlap one another (FIGS. 7a and 7b). The two woven fabric ends 2a, 2b subsequently are connected to one another by a woven fabric connection 1. To this end, the longitudinal thread ends 3a, 3b by way of one or a plurality of connecting elements 4 are usually connected to one another in a materially integral manner. The connecting elements 4, in the form of threads, extend in the transverse direction of the clothing 10, for example. The connection here is performed in such a manner that the longitudinal thread ends 3a, 3b are in contact exclusively with the upper side of the connecting element 4, or the connecting elements 4, and are connected in a materially integral manner, in particular welded, to the latter. In order for the woven fabric connection to be adapted, a number of transverse threads 6 can be removed from the woven fabric ends 2a, 2b so as to increase the length of the longitudinal thread ends 3a, 3b. As is shown in FIG. 7c, the woven fabric connection 1 is advantageously oriented such that the lower side 5b of the at least one connecting element 4 points in the direction of the interior of the two-tier woven fabric being created. As has already been described, the materially integral connections can thus be implemented simply by means of transmission welding.

[0113] For producing a seam clothing 10, in particular of a press felt 10, seam loops 21 are formed at the fold locations 20. To this end, a certain number of transverse threads 6 are removed from the woven fabric at these locations. This removal often takes place prior to folding and depositing the clothing 10 onto itself.

[0114] By combining the seam loops 21 and connecting the latter by means of a pintle element so as to form a pintle seam 22, an endless woven fabric loop can be produced from the two-tier woven fabric, said endless woven fabric loop being able to be used as a basic structure for a clothing 10. The two possibilities shown in FIGS. 7d and 7e are available here.

[0115] In FIG. 7d, the seam loops 21 have been combined such that the woven fabric connection 1 is disposed in that tier that is closer to the paper side 11. It results in the process that the woven fabric connection 1 is disposed such that the lower side 5b of the at least one connecting element 4 is oriented in the direction of the running side 12 of the clothing 10. Such a woven fabric loop as in FIG. 7d can thus also be used as the first woven fabric tier 14 in a clothing 10 according to one aspect of the invention.

[0116] An alternative is shown in FIG. 7e. The seam loops 21 here have been combined such that the woven fabric connection 1 is disposed in that tier that is closer to the running side 12. It results in the process that the woven fabric connection 1 is disposed such that the lower side 5b of the at least one connecting element 4 is oriented in the direction of the paper side 11 of the clothing 10. Such a woven fabric loop as shown in FIG. 7e, not least owing to the simple production thereof, can also be advantageously used as the woven fabric tier 14, optionally also as the first woven fabric tier, in a clothing 10.

LIST OF REFERENCE SIGNS

[0117] 1 Woven fabric connection [0118] 2a First woven fabric end [0119] 2b Second woven fabric end [0120] 3a First longitudinal thread end [0121] 3b Second longitudinal thread end [0122] 4 Connecting element [0123] 5 Upper side [0124] 5b Lower side [0125] 6 Transverse threads [0126] 7 Core [0127] 8 Casing [0128] 10 Clothing [0129] 11 Paper side [0130] 12 Running side [0131] 13 Non-woven tier [0132] 14 First woven fabric tier [0133] 15 Further woven fabric tier [0134] 20 Fold location [0135] 21 Seam loop [0136] 22 Pintle seam