LAMINATED PAPER MACHINE CLOTHING

Abstract

The invention relates to a clothing (10) for a machine to manufacture or refine a fibrous web, in particular a paper, cardboard, or tissue web, comprising a substrate (40) and a grid structure (20) applied on the substrate (40), on which the fibrous web is transported when the clothing (10) is used as intended, wherein the grid structure (20′) comprises a plurality of first elements (24′), all of which aligned in a first direction, and a plurality of second elements (26′), all of which aligned in a second direction, which is different from the first direction, wherein the first elements (24′) penetrate the second elements (26′), forming the grid structure (20′), such that an underside of the first elements (24′) facing the substrate (40) and an underside of the second elements (26′) facing the substrate (40) are located in a common plane. In addition, the present invention relates to a method for producing such a clothing.

Claims

1. A method of making a paper product comprising: transporting a fibrous web on a multi-layer structured fabric to a press gap passage of a drying cylinder of a papermaking machine, the structured fabric comprising: a substrate; and a grid structure applied on the substrate, the grid structure having higher elasticity than the substrate, wherein the elasticity of the grid structure allows the grid structure to elastically deform in the press gap passage to enhance contact area between the fibrous web and the drying cylinder.

2. The method of claim 1, wherein the drying cylinder is a Yankee dryer.

3. The method of claim 1, wherein the grid structure comprises a plurality of first elements all of which are aligned in a first direction, and a plurality of second elements all of which are aligned in a second direction which differs from the first direction.

4. The method of claim 3, wherein the first elements are connected to the second elements at points where the first elements intersect the second elements.

5. The method of claim 3, wherein an underside of the first elements facing the substrate and an underside of the second elements facing the substrate are in a common plane.

6. The method of claim 3, wherein the plurality of first elements extend continuously across the structured fabric in the first direction and the plurality of second elements extend continuously across the structured fabric in the second direction.

7. The method of claim 3, wherein the entire top side, facing away from the substrate, of each first element is not in a common plane with the entire top side, facing away from the substrate, of each second element so as to form a pattern of parallel grooves across the structured fabric.

8. The method of claim 1, wherein the structured fabric is a structured through-air-dryer (TAD) sieve.

9. The method of claim 5, wherein a top of the first elements facing away from the substrate and a top of the second elements facing away from the substrate are not in a common plane.

10. The method of claim 5, wherein a distance between the underside and a top side of the first elements differs by at least 20% from a distance between the underside and a top side of the second elements.

11. The method of claim 5, wherein the grid structure further comprises at least a plurality of third elements, all of which are aligned in a third direction, which is oriented differently in reference to the first direction and the second direction, wherein an underside of the third elements facing the substrate is located in the common plane, which is defined by the underside of the first elements and the underside of the second elements.

12. The method of claim 1, wherein the substrate is a web comprising warp threads and weft threads.

13. The method of claim 1, wherein the grid structure comprises thermoplastic polyurethane, polyethylene terephthalate, polypropylene, polyamide or combinations thereof.

14. A papermaking machine, comprising: a drying cylinder configured to dry a fibrous web; and a multi-layer structured fabric that transports the fibrous web to a press gap passage of the drying cylinder, the structured fabric comprising: a substrate; and a grid structure applied on the substrate, the grid structure having higher elasticity than the substrate, wherein the elasticity of the grid structure allows the grid structure to elastically deform in the press gap passage to enhance contact area between the fibrous web and the drying cylinder.

Description

[0029] Based on exemplary embodiments, additional advantageous variants of the invention are explained with reference to the drawings. The features mentioned can be advantageously implemented not only in the combination shown, but also individually combined with each other. The non-scale figures show in detail:

[0030] FIG. 1A detail of a grid structure according to a first exemplary embodiment,

[0031] FIG. 2A section through plane II-II in FIG. 1,

[0032] FIG. 3A section through plane in FIG. 1,

[0033] FIG. 4A detail of a grid structure according to a second exemplary embodiment,

[0034] FIG. 5A section through plane V-V in FIG. 4, supplemented by an adhesive layer and a substrate.

[0035] The figures are described in more detail below. FIG. 1 shows a small detail of a grid structure 20, which is surrounded by a dashed line. Here, the direction of sight in FIG. 1 is focused on the underside 22 of the grid structure, i.e. on the side which faces the substrate 40 in the finished clothing (see FIG. 5). The grid structure 20 consists of a plurality of first elements 24, all of which are aligned parallel to each other and extend in FIG. 1 in a vertical direction, and a plurality of second elements 26, which are likewise formed parallel to each other and extend in the horizontal direction in FIG. 2. The first elements 24 and the second elements 26 penetrate each other in order to form the grid structure 20. The first elements 24 and the second elements 26 can be made from an extruded plastic, such as TPU, and then merged with each other to form a grid. In the present exemplary embodiment, the distance between the first elements 24 is constant and corresponds to the distance between the second elements 26, which is also constant. Thus, a regular arrangement of substantially rectangular, particularly square, openings 28 in the grid structure 20 results. Due to the manufacturing process, with which the first elements 24 and the second elements 26 are merged with each other, the openings 28 are not necessarily embodied with sharp edges, but can have slightly rounded corners, as shown in the present exemplary embodiment. The area, which is formed by an underside 30 of the first elements 24 and an underside 32 of the second elements 26, is substantially planar and represents in FIG. 1 at least 60% of the total area, i.e. the area which is surrounded by the dashed frame in FIG. 1. Thus, a sufficiently large contact area for a reliable connection of the grid structure 20 to the substrate 40 is also provided with simple means, such as an adhesive.

[0036] FIG. 2 shows a section through plane II-II in FIG. 1. Here, it can be seen that the first element 24 shows a greater thickness, i.e. dimension in a vertical direction in FIG. 2, than the second element 26. In other words, the measurement of the underside 30 is greater than a top 34 of the first element 24 than the measurement of the underside 32 to a top 36 of the second element 26. Because the underside 30 of the first element 24 and the underside 32 of the second element 26 lie in the same plane, a profiling of the top part of the grid structure 20 is yielded, which in the intended use of the clothing 10 (see FIG. 5) faces the fibrous web to be manufactured or to be refined. This profiling is advantageous to the fibrous web, which thus shows only the pattern of openings 28, but also the pattern of parallel grooves, that are yielded by the various heights of the first elements 24 and second elements 26. As can be seen in FIG. 2, the first 5 elements 24 can have a cross-section orthogonal to its longitudinal direction of extension, which is rounded at the top, so that the top 24 of the first element 24 is formed only by a line which runs in the longitudinal direction of extension of the first element 24. The second element 26 can be configured this way, as well, although with lower height. Preferably, both the first elements 24 as well as the second elements 26 show a substantially equal cross-section everywhere along orthogonal in reference to the entire length of the longitudinal extension, wherein the material on the intersection points of the first elements 24 and the second elements 26 can run as already described before, which can lead to rounded corners of the openings 28.

[0037] FIG. 3 shows a section through plane III-III in FIG. 1. For reasons of simplicity, only the first element 24 is shown in this figure and not the second elements 26, which are completely merged in this sectional view with the first element 24.

[0038] FIG. 4 shows a view identical to FIG. 1, but illustrating a second embodiment of a grid structure 20′. Identical features of the second embodiment are equipped with identical reference signs as shown in the first embodiment, but showing an apostrophe. In this respect, reference is made to the above description.

[0039] The second embodiment differs from the first embodiment only in that the distance between the second elements 26′ is greater than the distance between the first elements 24′. Thus, there are no substantially square, but rather essentially rectangular, openings 28′ with an oblong shape.

[0040] FIG. 5 shows a section through plane V-V in FIG. 4. This sectional view corresponds in the essential sectional view in FIG. 2 to the first embodiment. However, in FIG. 5, in addition to the grid structure 20′, the substrate 40 is also shown, which consists in this exemplary embodiment of a single-layer fabric with wharf and weft threads and an adhesive layer 38 arranged between the grid structure 20′ and the substrate 40. Thus FIG. 5 shows a section of the finished clothing 10 which is limited by a dashed frame.

[0041] The clothing 10 is produced by first generating the grid structure 20′ and the substrate 40 separately. Then, the grid structure 20′ is equipped with the adhesive layer 38 and then laminated onto the substrate.

[0042] Both in the first embodiment according to FIGS. 1-3, as well as in the second embodiment according to FIGS. 4 and 5, the first element 24, 24′ extends preferably in the machine direction, when the clothing 10 is used as intended, and the second elements 26, 26′ extend in the machine transverse direction. Alternatively, however, the first elements 24, 24′ can extend in the machine transverse direction and the second elements 26, 26′ in the machine direction.

LIST OF REFERENCE CHARACTERS

[0043] 10 Clothing [0044] 20, 20′ Grid structure [0045] 22 Underside of the grid structure [0046] 24, 24′ first elements [0047] 26, 26′ second elements [0048] 28, 28′ Openings [0049] 30 Underside of the first elements [0050] 32 Underside of the second elements [0051] 34 Top of the first element [0052] 36 Top of the second element [0053] 38 Adhesive layer [0054] 40 Substrate