Papermaker's fabric

Abstract

To provide a woven fabric for papermaking excellent in both running stability and dehydration property.SOLUTION: The paper-making woven fabric 1 includes a paper-making side layer including upper warps 4 and upper wefts 5 woven with each other, and a running side layer including lower warps 6 and lower wefts 7 woven with each other. The paper-making side layer and the running side layer contain weft self-binding yarns 8. In the complete design, a lower weft yarn 7 is woven in such a manner that it passes over two successive lower warp yarns 6 and then passes under the lower warp yarns 6. The weft self-binding yarns 8 include a weft self-binding yarn 8 (first weft self-binding yarn) woven so as to pass under at least two successive lower warp yarns 6 and pass over the lower warp yarns 6 before and after the lower warp yarns 6. The lower warp yarns 6 are adjacent to each other and form a lower warp yarn pair 10 in which two lower warp yarns are woven into the same lower weft yarn. The paired lower warps belonging to the same lower warp pair are woven with different first weft self-binding yarns.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a papermaking fabric comprising a running surface side layer and a papermaking surface side layer, both layers being bound to each other with self-binding yarns. [Background technology]

[0002] Papermaking fabrics are used as papermaking wires that transport wet paper in the wire part of a papermaking machine, etc. To meet the demands of improving the quality of the paper produced and increasing production efficiency through faster production speeds, papermaking wires are required to have running stability to run steadily without wrinkles or meandering, dewatering and breathability to remove as much water as possible from the raw material liquid, surface properties (paper surface properties) to prevent surface irregularities from being transferred and remaining on the paper, stain resistance to prevent clogging and adhesion of adhesive components, abrasion resistance to withstand wear, and the ability to maintain the thickness of the wet paper to ensure a uniform thickness of the paper produced.

[0003] A papermaking fabric comprising a running surface side layer and a papermaking surface side layer combines both properties by constructing the papermaking surface side layer with an emphasis on surface properties and the running surface side layer with an emphasis on abrasion resistance. The papermaking surface side layer and the running surface side layer are joined by binding yarns. Yarns that function both as weave-forming yarns and as binding yarns are called self-binding yarns, and self-binding yarns arranged in the weft direction are called weft-self-binding yarns or self-binding weft yarns. A papermaking fabric in which the papermaking surface side layer and the running surface side layer are bound to each other by self-binding yarns is also called a triple weave SSB (sheet support binder).

[0004] In the inventions of Patent Documents 1 to 3, for example, regarding such papermaking fabrics, in the complete design, each of the lower wefts (running surface side weft, bottom CD yarn, bottom CMD yarn) which are the wefts of the running surface side layer passes over two consecutive lower warps (running surface side warp, bottom MD yarn, bottom MD yarn) which are the warps of the running surface side layer, and passes under the lower warps in other parts, and the multiple lower wefts in the complete design are woven into the lower warps at positions offset by one from each other. In this way, the offsetting of the positions at which the lower wefts weave into the lower warps gives the papermaking fabric high strength in the diagonal direction, making it less susceptible to deformation and improving running stability.

[0005] Furthermore, for example, in the inventions described in Patent Documents 4 to 7, two adjacent lower warps (back warp, bottom MD yarn, auxiliary bottom MD yarn, lower surface side warp, bottom warp) form a pair, and a lower weft (back weft, bottom CMD yarn, lower surface side weft, bottom weft) is woven with respect to the pair of lower warps (passing over the two lower warps that form the pair and passing under the lower warps before and after them). As a result, the two lower warps that form the pair are close to each other, and the gap between the pair of lower warps and the other lower warps adjacent to them is wide. These gaps are aligned in a linear row in the warp direction, improving dewatering properties. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-248086 [Patent Document 2] Special Publication No. 2013-501153 [Patent Document 3] Japanese Patent Application Laid-Open No. 2007-84994 [Patent Document 4] Japanese Patent Application Publication No. 2019-178437 [Patent Document 5] Japanese Patent Publication No. 2022-31822 [Patent Document 6] Japanese Patent Application Publication No. 2023-16487 [Patent Document 7] Special Publication No. 2005-524781 Summary of the Invention [Problem to be solved by the invention]

[0007] Although the papermaking fabrics described in Patent Documents 1 to 3 provide good running stability, the lower warp threads tend to meander, shifting to the right or left, resulting in scattered gaps between the lower warp threads within the plane, resulting in insufficient dewatering performance in applications where the speed of dewatering the pulp raw material liquid is important.

[0008] Although the papermaking fabrics described in Patent Documents 4 to 7 have good dewatering properties, the connections between the lower warp pair and the adjacent lower warp are weak, and the papermaking fabric has only weak rigidity in the diagonal direction, making it prone to deformation and reducing running stability. In particular, the longer the distance (crimp) that the lower weft passes under the lower warp in order to improve abrasion resistance, the fewer the points of contact (entanglement) between the lower warp and the lower weft, resulting in a significant reduction in running stability.

[0009] In view of the above background, an object of the present invention is to provide a papermaking fabric having both good running stability and good dewatering properties. [Means for solving the problem]

[0010] The terms used in this specification and claims are explained below. "Weave" refers to the way warp and weft threads intertwine. "Complete weave" refers to the smallest unit of the basic weave of a fabric, and a fabric is woven by expanding the complete weave back and forth and left and right. With regard to the warp and weft threads, the papermaking side is referred to as "top" and the running side as "bottom." The "warp direction" is the direction in which the warp threads extend, roughly corresponding to the length direction (machine direction (MD)) of a papermaking fabric. The "weft direction" is the direction in which the weft threads extend, roughly corresponding to the width direction (cross-machine direction (CMD)) of a papermaking fabric and perpendicular to the warp direction. The "warp cross section" is a cross section of a papermaking fabric parallel to the thickness direction and warp direction, and the "weft cross section" is a cross section of a papermaking fabric parallel to the thickness direction and weft direction.

[0011] In order to solve the above-mentioned problems, one aspect of the present invention is a papermaking fabric comprising a papermaking surface side layer (2, 22, 32) including upper warp yarns (4) and upper weft yarns (5) woven together, and a running surface side layer (3, 23, 33) including lower warp yarns (6) and lower weft yarns (7) woven together, wherein the papermaking surface side layer and the running surface side layer include weft self-binding yarns (8, 38) that are woven into both the upper warp yarns and the lower warp yarns to form a woven fabric design, and in the complete design, the lower weft yarns are two continuous The weft self-binding yarns are woven so as to pass over the lower warp threads and pass under the lower warp threads before and after them, and the weft self-binding yarns include first weft self-binding yarns (8, 38a) which are woven so as to pass under at least two consecutive lower warp threads and pass over the lower warp threads before and after them, and the lower warp threads include pair-forming lower warp threads (6) which are adjacent to each other and form a set of two lower warp thread pairs (10) which are woven into the common lower weft thread, and a pair of pair-forming lower warp threads belonging to the common lower warp thread pair are woven into the different first weft self-binding yarns.

[0012] According to this aspect, the lower weft is woven into the lower warp pair, which increases the linearity of the lower warp, narrowing the gaps between the lower warp threads belonging to the same lower warp pair and widening the gaps between the lower warp threads belonging to different lower warp pairs. Thus, the gaps between the lower warp threads belonging to different lower warp pairs are wider in the weft direction and extend linearly in the warp direction, simplifying the water passage path and improving dewatering speed. Furthermore, the weft self-binding yarn weaves the lower warp threads belonging to different lower warp pairs, thereby connecting the lower warp pairs. This provides the papermaking fabric with high rigidity in the diagonal direction, making it less susceptible to deformation and improving running stability.

[0013] In the above embodiment, in the complete design, all the lower warps (6) may form the lower warp pairs (10).

[0014] According to this embodiment, the dewatering property of the papermaking fabric is further improved.

[0015] In the above embodiment, all of the weft self-bonding yarns (8) in the complete design may be the first weft self-bonding yarns (8).

[0016] According to this embodiment, the rigidity of the papermaking fabric in the diagonal direction is further improved.

[0017] In the above embodiment, the upper warp threads (4) and the lower warp threads (6) constituting the complete design may each have 10 threads, and the lower weft thread (7) may be woven into the lower warp threads so as to pass over two consecutive lower warp threads and under eight consecutive lower warp threads in sequence, and the first weft self-binding thread (8) may be woven into the upper warp threads and the lower warp threads so as to pass under two consecutive lower warp threads, between two pairs of the upper warp threads and the lower warp threads, over one upper warp thread, between one pair of the upper warp threads and the lower warp threads, over one upper warp thread, between one pair of the upper warp threads and the lower warp threads, over one upper warp thread, between one pair of the upper warp threads and the lower warp threads, over one upper warp thread, between two pairs of the upper warp threads and the lower warp threads in sequence.

[0018] In the above embodiment, the upper weft (5) includes a first upper weft (5a) that forms one row of plain weave by itself, and a second upper weft (5b) that forms a plain weave in cooperation with adjacent weft self-binding yarns (8, 38), and one second upper weft and two adjacent weft self-binding yarns may form two rows of plain weave in cooperation with each other.

[0019] According to this embodiment, at least one weft self-binding yarn is arranged between a pair of upper weft and lower weft and another pair of upper weft and lower weft, thereby suppressing misalignment between the papermaking surface side layer and the running surface side layer and reducing internal wear.

[0020] According to this embodiment, the papermaking surface side layer and the running surface side layer are in close contact with each other, and the thickness of the papermaking fabric 1 can be made thin.

[0021] In the above embodiment, the upper weft (5), the lower weft (7) and the weft self-binding yarn (8) constituting the complete design may be 15, 10 and 10, respectively (first embodiment).

[0022] According to this embodiment, the ratio of the number of weft threads forming the fabric of the papermaking surface side layer to the number of lower weft threads is relatively large, so the area supporting the fibers of the pulp raw material is large, the paper surface properties are good, and the yield of the fibers of the pulp raw material is improved.

[0023] In the above embodiment, the upper weft (5), the lower weft (7) and the weft self-binding yarn (8) constituting the complete design may be 15, 15 and 10, respectively (second embodiment).

[0024] According to this embodiment, the ratio of the number of lower weft yarns that come into contact with the rolls or foils of the papermaking machine to the number of weft yarns that form the fabric structure of the papermaking surface side layer is relatively large, which increases the wear resistance and extends the life of the papermaking fabric.

[0025] In the above aspect, the weft self-binding yarn (38) may further include a second weft self-binding yarn (38b) that passes under one of the lower warp threads and is woven in so as to pass over the lower warp thread before and after that (third embodiment).

[0026] Even if a second weft self-binding yarn that does not have the function of connecting warp pairs is mixed in as in this embodiment, the main effects of the present invention are not impaired.

[0027] In the above embodiment, the upper warp threads (4) and the lower warp threads (6) constituting the complete design each have 10 threads, the lower weft thread (7) is woven into the lower warp threads so as to pass over two consecutive lower warp threads and under eight consecutive lower warp threads in order, and the first weft self-binding thread (38a) passes under two consecutive lower warp threads, between two pairs of the upper warp threads and the lower warp threads, over one upper warp thread, between one pair of the upper warp threads and the lower warp threads, over one upper warp thread, between one pair of the upper warp threads and the lower warp threads, and between one pair of the upper warp threads and the lower warp threads. The second weft self-binding yarn (38b) may be woven into the upper warp and the lower warp so as to pass over the upper warp, between two sets of the upper warp and the lower warp, in order, repeatedly, and the second weft self-binding yarn (38b) may be woven into the upper warp and the lower warp so as to pass under one lower warp, between one set of the upper warp and the lower warp, over one upper warp, between one set of the upper warp and the lower warp, over one upper warp, between one set of the upper warp and the lower warp, over one upper warp, between three sets of the upper warp and the lower warp.

[0028] According to this embodiment, even in an embodiment including the second weft self-bonding yarn, a complete design can be formed in a rational manner. [Effects of the Invention]

[0029] According to the above-mentioned embodiment, a papermaking fabric having both good running stability and good dewatering properties can be provided. [Brief explanation of the drawings]

[0030] [Figure 1] A complete structure diagram of the papermaking fabric according to the first embodiment [Figure 2] 1 is a schematic weft cross-sectional view of a papermaking fabric according to a first embodiment (a cross-section perpendicular to the warp direction, i.e., a view from the weft cross-sectional direction). [Figure 3] 1 is a bottom view of the running surface layer of the papermaking fabric according to the first embodiment. [Figure 4]Photographs of a sample of a papermaking fabric according to the first embodiment (A: Photograph taken from below (arrow IVA in Figure B), B: Photograph of the cross section of the sample cut in the weft direction (cross section IV-IV in Figure A)) [Figure 5] A complete structure diagram of a papermaking fabric according to the second embodiment [Figure 6] Schematic weft cross-sectional view of a papermaking fabric according to a second embodiment. [Figure 7] A complete structure diagram of a papermaking fabric according to the third embodiment [Figure 8] Schematic weft cross-sectional view of a papermaking fabric according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a structure diagram of a papermaking fabric 1 according to a first embodiment, Fig. 2 is a schematic diagram of a weft cross section of the papermaking fabric 1, Fig. 3 is a schematic diagram of the running surface side layer 3 of the papermaking fabric 1 as viewed from below, and Fig. 4 is a photograph of a sample of the papermaking fabric 1. The papermaking fabric 1 is used as a wire in the wire part of a papermaking machine. As shown in Figs. 1 to 4, the papermaking fabric 1 comprises a papermaking surface side layer 2 and a running surface side layer 3. When the papermaking fabric 1 is attached to a papermaking machine and becomes endless in the length direction, the running surface side layer 3 is positioned on the inside and comes into contact with the roll that runs the papermaking fabric 1, and the papermaking surface side layer 2 is positioned on the outside and carries the pulp stock liquid.

[0032] The papermaking surface side layer 2 includes upper warps 4 extending in the warp direction and upper wefts 5 extending in the weft direction, and the upper warps 4 and upper wefts 5 are woven together. The running surface side layer 3 includes lower warps 6 extending in the warp direction and lower wefts 7 extending in the weft direction, and the lower warps 6 and lower wefts 7 are woven together. The papermaking surface side layer 2 and the running surface side layer 3 include weft self-binding yarns 8 that are woven with both the upper warps 4 and the lower warps 6 to form a fabric design, thereby binding the papermaking surface side layer 2 and the running surface side layer 3 together.

[0033] "#" (number sign) in Figures 1 to 3 indicates the number (No.) of the warp or weft in the complete design (the same applies to Figures 5 to 8). Warp Nos. 1 to 10 are upper warps 4. Warp Nos. 11 to 20 are lower warps 6. Weft Nos. 5n+1, 5n+2, and 5n+4 (n is an integer from 0 to 4) are upper wefts 5. Weft Nos. 5n+3 and 5n+5 (n is an integer from 0 to 4) (yarns with numbers enclosed in squares in Figure 1) are weft self-bonding yarns 8. Weft Nos. 26 to 35 are lower wefts 7.

[0034] The symbols in Fig. 1 will be explained below (the meaning of each symbol is the same in Figs. 5 and 7). At the locations where the upper weft 5 crosses the upper warp 4, a circle indicates that the upper weft 5 passes above the upper warp 4, and a location without a circle indicates that the upper weft 5 passes below the upper warp 4 (here, since the upper weft 5 is not woven into the lower warp 6, the upper weft 5 passing "below the upper warp 4" means that it passes between the upper warp 4 and the lower warp 6. This also applies to the second and third embodiments described below). At the locations where the weft self-bonding yarn 8 crosses the upper warp 4 and the lower warp 6, a triangle indicates that the weft self-bonding yarn 8 passes above the upper warp 4, a ▼ indicates that the weft self-bonding yarn 8 passes below the lower warp 6, and a location without either a triangle or a ▼ indicates that the weft self-bonding yarn 8 passes between the upper warp 4 and the lower warp 6. At the points where the lower weft 7 crosses the lower warp 6, the points marked with ■ indicate that the lower weft 7 passes over the lower warp 6 (here, since the lower weft 7 is not woven into the upper warp 4, when we say that the lower weft 7 passes "over the lower warp 6", we mean that it passes between the upper warp 4 and the lower warp 6. The same applies to the second and third embodiments described below), and the points without ■ indicate that the lower weft 7 passes under the lower warp 6. Note that the parts marked with ▼ are hatched with diagonal lines, and the parts marked with ■ are hatched with a diagonal grid.

[0035] As shown in FIG. 1, the complete design of the papermaking fabric 1 is composed of 10 upper warps 4, 15 upper wefts 5, 10 lower warps 6, 10 lower wefts 7, and 10 weft self-binding yarns 8. In the complete design, a total of seven upper wefts 5, lower wefts 7, and weft self-binding yarns 8 of weft Nos. 5n+1, 5n+2, 5n+3, 5n+4, 5n+5, 5n+26, and 5n+27 (n is an integer from 0 to 4) form a block 9, and the upper wefts 5, lower wefts 7, and weft self-binding yarns 8 of each block 9 are woven into the upper warps 4 and lower warps 6 at a position shifted by two upper warps 4 and two lower warps 6 to the right of the page in Fig. 1 (where the warp numbers are smaller) relative to the upper wefts 5, lower wefts 7, and weft self-binding yarns 8 of the other block 9 adjacent to the bottom of the page in Fig. 1 (where the weft numbers are smaller). The following explanation will mainly focus on the blocks 9 of the upper wefts 5, lower wefts 7, and weft self-binding yarns 8 of weft Nos. 1 to 5, 26, and 27.

[0036] As shown in Figures 1 and 2, the upper weft 5 includes a first upper weft 5a (wefts No. 5n+1 and 5n+2) that forms one row of plain weave by itself, and a second upper weft 5b (weft No. 5n+4) that forms the plain weave in cooperation with the adjacent weft self-binding yarns 8 (wefts No. 5n+3 and 5n+5). For example, one row of plain weave is formed by the portion of the second upper weft 5b of weft No. 4 that intersects with the upper warp 4 of warp Nos. 4 to 8, and the portion of the weft self-binding yarn 8 of weft No. 3 that intersects with the warp Nos. 1 to 3 and 9 to 10. Also, one row of plain weave is formed by the portion of the second upper weft 5b of weft No. 4 that intersects with the upper warp 4 of warp Nos. 1 to 3 and 9 to 10, and the portion of the weft self-binding yarn 8 of weft No. 5 that intersects with the warp Nos. 4 to 8. In this way, two rows of plain weave are formed by one second upper weft 5b and two weft self-binding yarns 8. Therefore, in the paper-making surface side layer 2, four rows of plain weave are formed in the weft direction of each block 9, and 20 rows of plain weave are formed in the weft direction of the complete design.

[0037] As shown in FIGS. 1 to 3, the lower weft 7 is woven into the lower warp 6 by repeatedly passing over two consecutive lower warps 6 and under eight consecutive lower warps 6 in this order. Regarding the way in which the lower weft 7 is woven into the lower warp 6, the lower warps 6 of adjacent warps No. 2m+11 and 2m+12 (m is an integer from 0 to 4) form a lower warp pair 10. In this embodiment, all the lower warps 6 are pair-forming lower warps that form the lower warp pair 10. A pair of lower warps 6 that form each lower warp pair 10 is woven into a common lower weft 7. For example, the lower weft 7 of weft No. 26 passes over the lower warps 6 of warps No. 19 and 20, and passes under the lower warps 6 of warps No. 11 to 18. The lower weft 7 of weft No. 27 passes over the lower warps 6 of warps No. 13 and 14, and passes under the lower warps 6 of warps No. 15-20 and 11-12. Thus, in the complete design, each lower weft 7 passes over one lower warp pair 10 and passes under the remaining four lower warp pairs 10. That is, the lower weft 7 of weft No. 5n+27 is woven into the lower warp 6, shifted by four lower warps 6 toward the left of the page in FIG. 1 (toward the direction of increasing warp numbers) relative to the lower weft 7 of weft No. 5n+26. Furthermore, two lower wefts 7 are woven in such a way that they pass over each lower warp pair 10 in the complete design.

[0038] The weft self-binding yarn 8 is woven into the upper warp yarns 4 and lower warp yarns 6 so as to pass repeatedly in this order under two consecutive lower warp yarns 6, between one set of upper warp yarns 4 and lower warp yarns 6, over one upper warp yarn 4, between one set of upper warp yarns 4 and lower warp yarns 6, over one upper warp yarn 4, between one set of upper warp yarns 4 and lower warp yarns 6, over one upper warp yarn 4, between one set of upper warp yarns 4 and lower warp yarns 6, over one upper warp yarn 4, and between two sets of upper warp yarns 4 and lower warp yarns 6. The weft self-binding yarn 8 of weft No. 5n+3 is woven in this order toward the left side of the paper in Figure 1, and the weft self-binding yarn 8 of weft No. 5n+5 is woven in this order toward the right side of the paper in Figure 1.

[0039] The weft self-binding yarns 8 belong to different lower warp pairs 10 and are woven so as to pass under two consecutive lower warps 6 adjacent to each other. In other words, a pair of lower warps 6 (pair-forming lower warps) in each lower warp pair 10 are woven with different weft self-binding yarns 8. For example, the lower warps 6 of warp Nos. 15 and 16 form the lower warp pair 10, and the lower warps 6 of warp Nos. 17 and 18 form the lower warp pair 10, and the weft self-binding yarn 8 of weft No. 3 passes under the lower warps 6 of warp Nos. 16 and 17, i.e., under two lower warps 6 that belong to different lower warp pairs 10 and are adjacent to each other. Similarly, the lower warps 6 of warp Nos. 11 and 12 form a lower warp pair 10, and the lower warps 6 of warp Nos. 19 and 20 form a lower warp pair 10, and the weft self-binding yarn 8 of weft No. 5 passes under the lower warps 6 of warp Nos. 20 and 11. In the complete design, two weft self-binding yarns 8 are woven in such a way that they pass under each of the rows of two adjacent lower warps 6 that belong to different lower warp pairs 10.

[0040] As shown in Figure 4, in order to improve the paper surface properties affected by the paper-making side layer 2 and the abrasion resistance affected by the running side layer 3, it is preferable that the upper warp 4 and upper weft 5 are relatively thin and the lower warp 6 and lower weft 7 are relatively thick. In order to improve the paper surface properties, it is preferable that the weft self-binding yarn 8 has approximately the same thickness as the upper weft 5.

[0041] The materials constituting the upper warp 4, upper weft 5, lower warp 6, lower weft 7, and weft self-binding yarn 8 are not particularly limited, but polyamide-based resins and polyester-based resins are preferred. The polyamide-based resin is preferably an aliphatic polyamide resin, and nylon is more preferred. Examples of nylon include nylon 66, nylon 6, nylon 12, nylon 11, nylon 610, and nylon 612. These may be used alone or in combination of two or more. The polyester-based resin is not particularly limited as long as it is a polyester composed of a dicarboxylic acid and a glycol, and may be polyethylene terephthalate (PET), polypropylene terephthalate, polybutylene terephthalate (PBT), polyethylene naphthalate, etc. These may be used alone or in combination of two or more. The upper warp 4, upper weft 5, lower warp 6, lower weft 7, and weft self-binding yarn 8 may be made of the same material or different materials. Each yarn may be made of a single material, or two or more different materials. Furthermore, each yarn may contain inorganic and / or organic fillers.

[0042] The effects of the papermaking fabric 1 will be described with reference to Figures 1 to 4. Because the lower weft 7 is woven into the lower warp pairs 10, the linearity of the lower warp 6 is increased, the gap between a pair of lower warp threads 6 (pair-forming warp threads) forming each lower warp pair 10 is narrowed, and the gap between adjacent lower warp pairs 10 is widened. In this way, the gap between adjacent lower warp threads 6 belonging to different lower warp pairs 10 is widened in the weft direction and extends linearly in the warp direction, simplifying the water passage path and improving dewatering speed.

[0043] The weft self-binding yarn 8 weaves two consecutive lower warps 6 belonging to different lower warp pairs 10, and therefore functions to connect the lower warp pairs 10. This improves the rigidity of the papermaking fabric 1 in the diagonal direction, making the papermaking fabric 1 less likely to deform, and improving running stability.

[0044] The weft self-binding yarn 8 passes between two sets of upper warps 4 and lower warps 6 on one side of the front and rear of the section where two lower warps 6 are woven in (where it passes under the lower warps 6), and passes between one set of upper warps 4 and lower warps 6 on the other side. In this way, the weft self-binding yarn 8 passes between a total of three sets of upper warps 4 and lower warps 6 on the front and rear of the section where the lower warp 6 is woven in. Compared to when this number is set to four or more sets, the length of the weft self-binding yarn 8 passing between the upper warps 4 and lower warps 6 is shorter, so the papermaking surface side layer 2 and the running surface side layer 3 are in closer contact with each other, and the thickness of the papermaking fabric 1 can be reduced.

[0045] Next, a papermaking fabric 21 according to a second embodiment will be described with reference to Figures 5 and 6. In the description, components common to or similar to those of the first embodiment will be denoted by the same reference numerals and explanations of the common parts will be omitted. Figure 5 is a weave diagram of the papermaking fabric 21, and Figure 6 is a schematic diagram of the weft cross section of the papermaking fabric 21. The second embodiment differs from the first embodiment in the number of bottom wefts 7 in the complete weave.

[0046] The papermaking fabric 21 is used as a wire in the wire part of a papermaking machine, and comprises a papermaking side layer 22 and a running side layer 23. The papermaking side layer 22 includes upper warp yarns 4 and upper weft yarns 5 woven together, the running side layer 23 includes lower warp yarns 6 and lower weft yarns 7 woven together, and the papermaking side layer 22 and the running side layer 23 include weft-binding yarns 8.

[0047] As shown in Figure 5, the complete design of papermaking fabric 21 is composed of 10 top warps 4, 15 top wefts 5, 10 bottom warps 6, 15 bottom wefts 7, and 10 weft self-binding yarns 8. Warp Nos. 1 to 10 are top warps 4. Warp Nos. 11 to 20 are bottom warps 6. Weft Nos. 5n+1, 5n+2, and 5n+4 (n is an integer from 0 to 4) are top wefts 5. Weft Nos. 5n+3 and 5n+5 (n is an integer from 0 to 4) (threads with numbers enclosed in squares in Figure 1) are weft self-binding yarns 8. Weft Nos. 26 to 40 are bottom wefts 7. In the complete design, a total of eight upper wefts 5, lower wefts 7, and weft self-binding yarns 8, namely wefts No. 5n+1, 5n+2, 5n+3, 5n+4, 5n+5, 5n+26, 5n+27, and 5n+28 (n is an integer from 0 to 4), form blocks 29, and the upper wefts 5, lower wefts 7, and weft self-binding yarns 8 of each block 29 are woven into the upper warp 4 and lower warp 6, shifted by two upper warp 4 and two lower warp 6 to the left of the paper in Figure 5 (toward the larger warp number) relative to the upper wefts 5, lower wefts 7, and weft self-binding yarns 8 of the adjacent block 29 located at the bottom of the paper in Figure 5 (toward the smaller weft number).

[0048] 5 and 6, the upper weft 5 includes a first upper weft 5a (weft Nos. 5n+1 and 5n+2) which forms one row of plain weave by itself, and a second upper weft 5b (weft No. 5n+4) which forms a plain weave in cooperation with adjacent weft self-binding yarns 8 (weft Nos. 5n+3 and 5n+5). In the paper-making surface side layer 22, four rows of plain weave are formed in the weft direction of each block 29, and 20 rows of plain weave are formed in the weft direction of the complete design.

[0049] The lower weft 7 is woven into the lower warp 6 so as to pass over two consecutive lower warps 6 forming a lower warp pair 10 and then under eight consecutive lower warps 6 in this order. In this embodiment, all the lower warps 6 are pair-forming lower warps that form the lower warp pair 10. In each block 29, the lower weft 7 of weft No. 5n+27 is woven into the lower warp 6 with a shift of four lower warps 6 relative to the lower wefts 7 of weft Nos. 5n+26 and 5n+28, and the lower wefts 7 of weft Nos. 5n+26 and 5n+28 are woven into the lower warp 6 with a shift of two lower warps 6 relative to each other. In the complete design, three lower wefts 7 are woven into each lower warp pair 10 so as to pass over it.

[0050] Although the warp numbers of the upper warp 4 and lower warp 6 into which the weft self-binding yarns 8 are woven are different from those of the first embodiment, the repeat pattern of weaving is the same as that of the first embodiment. Also, like the first embodiment, a pair of lower warps 6 in each lower warp pair 10 (pair-forming lower warps) are woven into different weft self-binding yarns 8.

[0051] The papermaking fabric 21 according to the second embodiment has the same effects as those of the papermaking fabric 1 according to the first embodiment (see FIGS. 1 to 4). The effects of the papermaking fabrics 1, 21 according to the first and second embodiments differ from each other in the following respects. The papermaking fabric 1 according to the first embodiment has 20 plain weave rows in the weft direction in the complete design, and 10 bottom wefts 7, for a ratio of 2:1. The papermaking fabric 1 according to the second embodiment has 20 plain weave rows in the weft direction in the complete design, and 15 bottom wefts 7, for a ratio of 4:3. As described above, in the papermaking fabric 1 of the first embodiment, the ratio of the number of weft yarns (top weft yarns 5 and weft self-binding yarns 8) forming the weave of the papermaking surface side layer 2 to the number of bottom weft yarns 7 is larger than that of the papermaking fabric 21 of the second embodiment, resulting in a larger area supporting the fibers of the pulp material, better paper surface properties, and higher fiber retention of the pulp material. Conversely, in the papermaking fabric 21 of the second embodiment, the ratio of the number of bottom weft yarns 7 that come into contact with the rolls and foils of the papermaking machine to the number of weft yarns forming the weave of the papermaking surface side layer 22 is larger than that of the papermaking fabric 1 of the first embodiment, resulting in higher abrasion resistance and a longer lifespan of the papermaking fabric 21. Furthermore, in the papermaking fabric 21 of the second embodiment, the use of lower weft yarns 7 with a relatively large fiber diameter increases the rigidity in the weft direction and improves running stability.

[0052] Next, a papermaking fabric 31 according to a third embodiment will be described with reference to Figures 7 and 8. In the description, components common to or similar to those of the first embodiment will be denoted by the same reference numerals and explanations of the common parts will be omitted. Figure 7 is a weave diagram of the papermaking fabric 31, and Figure 8 is a schematic diagram of the weft cross section of the papermaking fabric 31. The third embodiment differs from the first and second embodiments mainly in that it includes two types of weft self-bonding yarns 38.

[0053] The papermaking fabric 31 is used as a wire in the wire part of a papermaking machine, and comprises a papermaking side layer 32 and a running side layer 33. The papermaking side layer 32 includes upper warp yarns 4 and upper weft yarns 5 woven together, the running side layer 33 includes lower warp yarns 6 and lower weft yarns 7 woven together, and the papermaking side layer 32 and the running side layer 33 include weft self-binding yarns 38.

[0054] As shown in Figure 7, the complete design of the papermaking fabric 31 is composed of 10 top warps 4, 20 top wefts 5, 10 bottom warps 6, 20 bottom wefts 7, and 20 weft self-binding yarns 38. Warp Nos. 1 to 10 are top warps 4. Warp Nos. 11 to 20 are bottom warps 6. Of weft Nos. 1 to 40, odd-numbered yarns are top wefts 5. Of weft Nos. 1 to 40, even-numbered yarns are weft self-binding yarns 38. Weft Nos. 41 to 60 are bottom wefts 7. In the complete design, a total of 12 upper wefts 5, lower wefts 7, and weft self-binding yarns 38, namely wefts No. 8n+1, 8n+2, 8n+3, 8n+4, 8n+5, 8n+6, 8n+7, 8n+8, 8n+41, 8n+42, 8n+43, and 8n+44 (n is an integer from 0 to 4), form blocks 39, and the upper wefts 5, lower wefts 7, and weft self-binding yarns 38 of each block 39 are woven into the upper warp yarns 4 and lower warp yarns 6, shifted by four upper warp yarns 4 and four lower warp yarns 6 to the right of the paper in Figure 7 (toward the smaller warp yarn numbers) relative to the upper wefts 5, lower wefts 7, and weft self-binding yarns 38 of the other block 39 adjacent to the bottom of the paper in Figure 7 (toward the smaller weft yarn numbers).

[0055] 7 and 8, the upper weft 5 includes first upper weft 5a (weft Nos. 8n+1 and 8n+5) which form one plain weave row by itself, and second upper weft 5b (weft Nos. 8n+3 and 8n+7) which form a plain weave in cooperation with adjacent weft self-binding yarns 38 (weft Nos. 8n+2, 8n+4, 8n+6 and 8n+8). In the paper-making side layer 32, six plain weave rows are formed in the weft direction of each block 39, and 30 plain weave rows are formed in the weft direction of the complete design.

[0056] The lower weft 7 is woven into the lower warp 6 so as to pass over two consecutive lower warps 6 forming a lower warp pair 10 and then under eight consecutive lower warps 6 in sequence. In this embodiment, all the lower warps 6 are pair-forming lower warps that form the lower warp pairs 10. The lower weft 7 of weft No. k (k is an integer between 41 and 60) is woven into the lower warp 6, shifted by four lower warps 6 to the left of the paper in FIG. 7 (towards larger warp numbers) relative to the lower weft 7 of weft No. k-1 (when k=0 and the weft No. is 40, it is read as weft No. 60). In the complete design, four lower wefts 7 are woven into each lower warp pair 10 so as to pass over it.

[0057] The weft self-binding yarn 38 includes a first weft self-binding yarn 38a (weft yarns No. 8n+2, 8n+6 and 8n+8) having a repeating weaving pattern similar to that of the weft self-binding yarn 8 of the first and second embodiments (see Figures 1 to 6), and a second weft self-binding yarn 38b (weft yarn No. 8n+4) that weaves in one lower warp yarn 6 in the complete design. The first weft self-bonding yarns 38a of wefts No. 8n+2 and 8n+8 are woven into the upper warp threads 4 and lower warp threads 6 toward the right side of the paper in Figure 7 (the side where the warp thread numbers become smaller), and the first weft self-bonding yarn 38a of weft No. 8n+6 is woven into the upper warp threads 4 and lower warp threads 6 toward the left side of the paper in Figure 7, repeatedly passing under two consecutive lower warp threads 6, between a set of upper warp threads 4 and lower warp threads 6, over one upper warp thread 4 ... two sets of upper warp threads 4 and lower warp threads 6. The second weft self-binding yarn 38b is woven into the upper warp threads 4 and lower warp threads 6 so as to pass, in order, to the left of the paper in Figure 7, under one lower warp thread 6, between three sets of upper warp threads 4 and lower warp threads 6, over one upper warp thread 4, between one set of upper warp threads 4 and lower warp threads 6, over one upper warp thread 4, between one set of upper warp threads 4 and lower warp threads 6, over one upper warp thread 4, between one set of upper warp threads 4 and lower warp threads 6, and over one upper warp thread 4, between one set of upper warp threads 4 and lower warp threads 6.

[0058] In Figure 7, the location where the first weft self-bonding binding yarn 38a weaves the lower warp 6 is indicated by a ▼ mark and solid diagonal hatching, and the location where the second weft self-bonding binding yarn 38b weaves the lower warp 6 is indicated by a ▼ mark and dashed diagonal hatching. The position where the first weft self-bonding binding yarn 38a of weft No. 8n+6 weaves the lower warp 6 is shifted by two lower warps 6 to the right in Figure 7 from the position where the first weft self-bonding binding yarn 38a of weft No. 8n+2 weaves the lower warp 6. The position where the first weft self-bonding binding yarn 38a of weft No. 8n+8 weaves the lower warp 6 is shifted by two lower warps 6 to the left in Figure 7 from the position where the first weft self-bonding binding yarn 38a of weft No. 8n+2 weaves the lower warp 6. The position where the second weft self-bonding binding yarn 38b of weft No. 8n+4 weaves into the lower warp 6 is shifted by five lower warps 6 from the position where the first weft self-bonding binding yarn 38a of weft No. 8n+2 weaves into the lower warp 6 of an even warp number. In the complete design, three first weft self-bonding binding yarns 38a pass underneath two lower warps 6 that are adjacent to each other but belong to different lower warp pairs 10, and one second weft self-bonding binding yarn 38b passes underneath a lower warp 6 of an odd warp number.

[0059] In the first and second embodiments, all of the weft self-binding yarns 8 (see FIGS. 1 to 6) correspond to the first weft self-binding yarns 38a. In contrast, in the third embodiment, a first weft self-binding yarn 38a that weaves two adjacent lower warps 6 and a second weft self-binding yarn 38b that weaves only one lower warp 6 are mixed. Even if the first weft self-binding yarns 38a and the second weft self-binding yarns 38b are mixed in this way, the papermaking fabric 31, like the first and second embodiments, has the following advantages: improved dewatering speed due to the lower weft 7 being woven into the lower warp pair 10; improved running stability due to the weft self-binding yarn 8 weaving into two consecutive lower warps 6 that belong to different lower warp pairs 10; and reduced thickness of the papermaking fabric 31 due to the short length of the weft self-binding yarns 38 that pass between the upper warp 4 and the lower warp 6.

[0060] Although the specific embodiments have been described above, the present invention is not limited to the above-described embodiments and modifications, and can be implemented in a wide variety of ways. The papermaking fabrics 1, 21, and 31 may be fabrics used in papermaking machines other than paper machines (e.g., pulp machines). The papermaking surface side layers 2, 22, and 32 may have a weave other than plain weave. The papermaking fabrics 1, 21, and 31 may include lower warps 6 that do not form a lower warp pair 10. In this case, the weft self-binding yarn 8 and the first weft self-binding yarn 38a are woven so as to pass under three or more consecutive lower warps 6, each consisting of one lower warp 6 on the adjacent side of each adjacent lower warp pair 10 and the other lower warp 6 that does not form a pair therebetween. In addition, in the above embodiment, when forming a plain weave design on the papermaking surface side, two weft self-binding yarns 8, 38 and one upper weft yarn 5 work together to form two rows of plain weave, but two weft self-binding yarns may also work together to form one row of plain weave. [Explanation of symbols]

[0061] 1,21,31:Papermaking fabric 2, 22, 32: Paper-making surface layer 3, 23, 33: Running surface layer 4: Upper warp 5: Upper weft 5a: 1st upper weft 5b: Second upper weft 6: Lower warp 7: Lower weft 8: Weft self-binding yarn (1st weft self-binding yarn) 10: Lower warp pair 38: Weft self-binding thread 38a: 1st weft self-binding yarn 38b: 2nd weft self-binding yarn

Claims

1. A papermaking fabric comprising a papermaking surface side layer including upper warp yarns and upper weft yarns woven together, and a running surface side layer including lower warp yarns and lower weft yarns woven together, the papermaking surface side layer and the running surface side layer include weft binding yarns that are woven with both the upper warp and the lower warp to form a woven fabric, thereby binding the papermaking surface side layer and the running surface side layer together; In a complete organization, The lower weft passes over two consecutive lower warps and is woven in such a way that it passes under the lower warps before and after the two consecutive lower warps, The weft self-binding yarn includes a first weft self-binding yarn woven so as to pass under at least two consecutive lower warps and pass over the lower warps before and after the first weft-binding yarn, The lower warp yarns include pair-forming lower warp yarns that are adjacent to each other and form a pair of lower warp yarns that are woven into the common lower weft yarn, A papermaking fabric, wherein a pair of pair-forming lower warps belonging to a common lower warp pair are woven into different first weft self-binding yarns.

2. The papermaking fabric of claim 1 , wherein in the complete design, all of the lower warps form lower warp pairs.

3. 3. The papermaking fabric according to claim 1, wherein in the complete design, all of the weft self-binding yarns are the first weft self-binding yarns.

4. The number of the upper warp threads and the lower warp threads constituting the complete design is 10 each, The lower weft is woven into the lower warp so as to pass over two consecutive lower warps and under eight consecutive lower warps in turn, The papermaking fabric of claim 3, wherein the first weft self-binding yarn is woven into the upper warp and lower warp so as to pass in sequence under two consecutive lower warp threads, between two sets of upper warp threads and lower warp threads, over one upper warp thread, between one set of upper warp threads and lower warp threads, over one upper warp thread, between one set of upper warp threads and lower warp threads, over one upper warp thread, and between two sets of upper warp threads and lower warp threads.

5. The upper weft yarns include a first upper weft yarn that forms one row of plain weave by itself, and a second upper weft yarn that forms a plain weave in cooperation with the adjacent weft self-binding yarn, 5. The papermaking fabric according to claim 4, wherein one second upper weft yarn and two adjacent weft self-binding yarns cooperate to form two rows of plain weave.

6. 5. The papermaking fabric according to claim 4, wherein the number of the upper weft, the lower weft, and the weft self-binding yarns constituting the complete design is 15, 10, and 10, respectively.

7. 5. The papermaking fabric according to claim 4, wherein the number of the upper weft, the lower weft, and the weft self-binding yarns constituting the complete design is 15, 15, and 10, respectively.

8. 2. The papermaking fabric according to claim 1, wherein in the complete weft self-binding yarn, the weft self-binding yarn further includes a second weft self-binding yarn woven in so as to pass under one of the lower warp yarns and then over the lower warp yarn before and after that.

9. The number of the upper warp threads and the lower warp threads constituting the complete design is 10 each, The lower weft is woven into the lower warp so as to pass over two consecutive lower warps and under eight consecutive lower warps in turn, The first weft self-binding yarn is woven into the upper warp and the lower warp so as to pass repeatedly in this order under two consecutive lower warps, between two sets of the upper warp and the lower warp, over one upper warp, between one set of the upper warp and the lower warp, over one upper warp, between one set of the upper warp and the lower warp, over one upper warp, and between two sets of the upper warp and the lower warp, The papermaking fabric of claim 8, wherein the second weft self-binding yarn is woven into the upper warp and lower warp so as to pass in sequence under one lower warp, between one set of the upper warp and the lower warp, over one upper warp, between one set of the upper warp and the lower warp, over one upper warp, between one set of the upper warp and the lower warp, over one upper warp, between one set of the upper warp and the lower warp, over one upper warp, and between three sets of the upper warp and the lower warp.

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