Paper maker fabric

Abstract

A fabric having a first woven fabric layer forming a paper side and made of first threads, and a second woven fabric layer made of second threads, the two woven fabric layers being connected by binder threads belonging to the first woven fabric layer such that at binding points the respective binder thread binds with one first thread on the paper side, then changes to the second woven fabric layer and binds with at least two second threads and then returns to the first woven fabric layer again and binds with a first thread on the paper side, wherein at binding points only one first thread is not bound by the said binder thread.

Claims

1. A paper maker fabric (1, 21) particularly usable as a forming fabric in a forming section of a paper making machine having a first woven fabric layer (2) forming a paper side on its outside and made of first threads (6, 7, 8) interwoven with one another, and a second woven fabric layer (3) forming a machine side on its outside and made of second threads (9, 10) interwoven with one another, the two woven fabric layers (2, 3) being connected to one another by intrinsic binder threads (7) belonging to the first woven fabric layer (2) such that at binding points (13) the respective binder thread (7) binds with a first thread (6a) extending transversely to the binder thread (7) by passing over its paper side, then changes to the second woven fabric layer (3) and binds with at least two adjacent second threads (9a, 9b) extending transversely to the binder thread (7) by passing over their machine side and then returns to the first woven fabric layer (2) again and binds with a first thread (6b) extending transversely to the binder thread (7) on the paper side, wherein at binding points (13) only one first thread (6c) extending transversely to the binder thread (7) is not bound by the said binder thread (7).

2. A paper maker fabric according to claim 1, wherein, the binder threads (7) extend transversely to the provided running direction of the paper maker fabric (1, 21).

3. A paper maker fabric according to claim 1, wherein, the binder threads (7) are weft threads.

4. A paper maker fabric according to claim 1, wherein, at least one binder thread (7) is provided within one weave pattern repeat of the first woven fabric layer (2).

5. A paper maker fabric according to claim 1, wherein, the binder threads (7) are separated from the respective adjacent binder threads (7) by at least one first thread (8) extending in the same direction and not being a binder thread (7), respectively.

6. A paper maker fabric according to claim 5, wherein, the binder threads (7) are separated from the respective adjacent binder thread (7) by more than one first thread (8) not being a binder thread (7).

7. A paper maker fabric according to claim 1, wherein, the first threads (6, 8) inclusive of their binder threads (7) form a plain weave on the paper side of the forming fabric (1, 21).

8. A paper maker fabric according to claim 1, wherein, the ratio of the number of the first threads (6) extending transversely to the binder threads (7) to the number of the second threads (9) extending transversely to the binder threads (7) amounts to 1:1, 2:1, 3.2, 4:3, 5:3 or 5:4.

9. A paper maker fabric according to claim 1, wherein, the second threads (9) extending transversely to the binder threads (7) are offset with respect to the first threads (6) extending transversely to the binder threads (7) so that the said second threads (9) are arranged below a gap between two adjacent first threads (6) extending transversely to the binder threads (7).

10. A paper maker fabric according to claim 1, wherein, said second threads (10) form floats (11) at the machine side passing a number of second threads (9) extending transversely to the floats (11) on the machine side, which is larger than the number of the second threads (9) which are bound by the second threads (10) between their floats (11).

11. A paper maker fabric according to claim 1, wherein, the threads (6, 9) extending in the running direction of the paper maker fabric (1, 21) are made of PET, PEN or of mixtures or copolymers of these materials and/or the threads (7, 8, 10) extending transversely to the provided running direction are made of PET, PA or mixtures or copolymers of these materials or blends of these materials with PU or other material suitable for use in the paper maker fabric.

12. A paper maker fabric according to claim 1, wherein, the threads (6, 7, 8, 9, 10) have a round, oval, or rectangular cross section or one with a profile being different to the above mentioned cross sections.

13. A paper maker fabric according to claim 1, wherein, threads are provided, which are twisted or braided from at least two monofilaments or multifilaments and/or which are provided with a coating, in particular made of urethane or acrylic, or using nanoparticles.

14. A paper maker fabric according to claim 2, wherein, at least one binder thread (7) is provided within one weave pattern repeat of the first woven fabric layer (2).

15. A paper maker fabric according to claim 3, wherein, at least one binder thread (7) is provided within one weave pattern repeat of the first woven fabric layer (2).

16. A paper maker fabric according to claim 2, wherein, the binder threads (7) are separated from the respective adjacent binder threads (7) by at least one first thread (8) extending in the same direction and not being a binder thread (7), respectively.

17. A paper maker fabric according to claim 3, wherein, the binder threads (7) are separated from the respective adjacent binder threads (7) by at least one first thread (8) extending in the same direction and not being a binder thread (7), respectively.

18. A paper maker fabric according to claim 4, wherein, the binder threads (7) are separated from the respective adjacent binder threads (7) by at least one first thread (8) extending in the same direction and not being a binder thread (7), respectively.

19. A paper maker fabric according to claim 5, wherein, the binder threads (7) are separated from the respective adjacent binder thread (7) by more than one first thread (8) not being a binder thread (7), and wherein the number of first threads (8) not being binder threads between two adjacent binder threads (7) is four at most.

20. A paper maker fabric (1, 21) particularly usable as a forming fabric in a forming section of a paper making machine having a first woven fabric layer (2) forming a paper side on its outside and made of first threads (6, 7, 8) interwoven with one another, and a second woven fabric layer (3) forming a machine side on its outside and made of second threads (9, 10) interwoven with one another, the two woven fabric layers (2, 3) being connected to one another by integral binder threads (7) belonging to the first woven fabric layer (2) such that at binding points (13) the respective binder thread (7) binds with a first thread (6a) extending transversely to the binder thread (7) by passing over its paper side, then changes to the second woven fabric layer (3) and binds with at least two adjacent second threads (9a, 9b) extending transversely to the binder thread (7) by passing over their machine side and then returns to the first woven fabric layer (2) again and binds with a first thread (6b) extending transversely to the binder thread (7) on the paper side, wherein at binding points (13) only one first thread (6c) extending transversely to the binder thread (7) is not bound by the said binder thread (7), wherein all the first threads extending in the same direction are interwoven as binder threads (7).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings, the invention is illustrated by means of exemplary embodiments. These show as follows:

(2) FIG. 1 a partial cross-section through a first woven paper maker fabric in accordance with the invention,

(3) FIG. 2 a partial cross-section through a second woven paper maker fabric in accordance with the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

(4) The paper maker fabric 1 shown in FIG. 1 has a first woven fabric layer 2 and a second woven fabric layer 3. The two woven fabric layers 2, 3 are laid over one another. The outside of the first woven fabric layer 2 forms the paper side 4 and the outside of the second woven fabric layer 3 forms the machine side 5 of the paper maker fabric 1.

(5) The first woven fabric layer 2 is made up of first longitudinal threads extending in the running direction of the paper maker fabric 1—identified for example by 6—and first transverse threads 7, 8 extending transversely to the latter, which both have a circular cross-section. The first transverse threads are composed of transverse binder threads 7 and first transverse threads 8 not being transverse binder threads 7. These two kinds of threads 7, 8 alternate one to another in the direction of the first longitudinal threads 6. The first transverse threads 7, 8 are in general interwoven in a plain weave.

(6) The second woven fabric layer 3 is made up by second longitudinal threads—identified for example by 9—extending in the running direction and by second transverse threads 10, of which a single second transverse thread 10 is shown. The second transverse threads 10 run such that they form floats 11 on the machine side passing under five second longitudinal threads 9. Between the floats 11, the second transverse threads 10 bind with one second longitudinal thread 9 in a knuckle 12. Due to the long floats 11 of the second transverse threads 10 one talks of a weft runner. The second longitudinal threads 9 have a circular cross-section as well as the second transverse threads 10, too. The ratio of the numbers of the first longitudinal threads 6 and the second longitudinal threads 9 is 1:1.

(7) At the binding point 13 the transverse binder thread 7 binds with a first longitudinal thread 6a by passing over its paper side, than changes from the first woven fabric layer 2 to the second woven fabric layer 3 by running nearly vertically, i.e. in thickness direction of the paper maker fabric 1, and binds in the second woven fabric layer 3 with two adjacent second longitudinal threads 9a, 9b by passing over their machine side. The two second longitudinal threads 9a, 9b are next to the knuckle 12 formed by the second transverse thread 10. Thereafter, the transverse binder thread 7 returns to the first woven fabric layer 2 and binds with a first longitudinal thread 6b. The first longitudinal threads 6a, 6b are separated by only one first longitudinal thread 6c. Consequently, at the binding point 13 only one first longitudinal thread 6c is being released from binding with the transverse binder thread 7, thus the plain weave structure being continued on the paper side of the forming fabric. Before and behind the binding point 13, the transverse binder thread 7 is interwoven with the other first threads 6, 8 in a plain weave, as well.

(8) FIG. 1 shows only one binding point 13. The number of binding points 13 can be chosen in accordance with the necessity to obtain a sufficient strong connection between the first and second woven fabric layers 2, 3. So, binding with two longitudinal second threads 9 can be realized at any point behind any knuckle 12.

(9) Another paper maker fabric 21 is illustrated in FIG. 2. It differs only slightly from the paper maker fabric 1 according to FIG. 1, and so here the reference numbers to be seen in FIG. 1 are used for the same parts in the woven paper maker fabric 21, and with regard to these parts, reference is made to the above mentioned description of the paper maker fabric 1 according to FIG. 1. The only difference is that in the paper maker fabric shown in FIG. 1 each second longitudinal thread 9 is exactly disposed below a single first longitudinal thread 6 forming pairs of first and second longitudinal threads 6, 9 lying one over the other, while the second longitudinal threads 9 of the paper maker fabric 21 are offset with respect to the first longitudinal threads 6 such that the second longitudinal threads 9 are disposed exactly below the middle of the gaps between the first longitudinal threads 6. A comparison between the two paper maker fabrics 1, 21 reveals that the course of the transverse binder thread 7 at the binding point 13 of the paper maker fabric 21 is more symmetrical than that of the transverse binder thread 7 in the paper maker fabric 1.

(10) It will be apparent to one of ordinary skill in the art that various modifications and variations can be made in construction or configuration of the present invention without departing from the scope or spirit of the invention. Thus, it is intended that the present invention cover all modifications and variations of the invention, provided they come within the scope of the following claims and their equivalents.