INDUSTRIAL FABRIC

Abstract

An industrial fabric 10 includes: first warps; second warps; first wefts; and second wefts. The first warps and the second warps are provided while being shifted in a weft direction. The first wefts and the second wefts are provided while being shifted in a warp direction. The second wefts are located on the upper surface side of the industrial fabric. The first warps are woven only into the first wefts. The second warps are woven into the first wefts and the second wefts.

Claims

1. An industrial fabric comprising: first warps; second warps; first wefts; and second wefts, wherein the first warps and the second warps are provided while being shifted in a weft direction, wherein the first wefts and the second wefts are provided while being shifted in a warp direction, wherein the second wefts are located on the upper surface side of the industrial fabric, wherein the first warps are woven only into the first wefts, wherein the second warps are woven into the first wefts and the second wefts, wherein a pair of the first warps are adjacent to each other in the weft direction so as to form a first warp pair, wherein a pair of the second warps are adjacent to each other in the weft direction so as to form a second warp pair, wherein the first wefts and the second wefts are arranged alternately, wherein the first warps have a weaving pattern of passing below all the second wefts and alternately going above and below the first wefts, and wherein the second warps form a weaving pattern of passing above one of the first wefts, one of the second wefts, and one of the first wefts in order and then passing below one of the second wefts, one of the first wefts, one of the second wefts, one of the first wefts, and one of the second wefts in order.

2. The industrial fabric according to claim 1, wherein the first warp pair and the second warp pair are arranged alternately in the weft direction.

3. The industrial fabric according to claim 1, wherein the adjacent first warps constituting the first warp pair are woven into the first wefts while being shifted from each other by one first weft with respect to the first wefts in the warp direction.

4. The industrial fabric according to claim 1, wherein a pair of the second warps constituting the second warp pair are woven into the second wefts while being shifted from each other by two second wefts with respect to the second wefts in the warp direction.

5. The industrial fabric according to claim 1, wherein the total number of the first warps and the second warps is eight and the total number of the first wefts and the second wefts is eight in a weave repeat that forms a repeating pattern of the industrial fabric.

6. The industrial fabric according to claim 3, wherein the weaving pattern of one of the first warps pairs and the weaving pattern of the other one of the first warp pairs are identical in a weave repeat that forms a repeating pattern of the industrial fabric.

7. The industrial fabric according to claim 1, wherein the density of the first warps and the density of the second warps are in the range of 90 percent to 140 percent.

8. The industrial fabric according to claim 1, wherein resin is applied to the upper surface of the industrial fabric.

9. The industrial fabric according to claim 1, wherein at least some of warps constituting the first warps or the second warps are conductive carbon yarns.

10. The industrial fabric according to claim 1, wherein the cross-sectional shape of the second wefts is elliptical or rectangular.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which:

[0008] FIG. 1 is a design diagram showing a weave repeat of an industrial fabric according to an exemplary embodiment.

[0009] FIG. 2A and FIG. 2B are a cross-sectional view in the warp direction along warps of the industrial fabric shown in FIG. 1.

[0010] FIG. 3 is a cross-sectional view along a first warp of the industrial fabric shown in FIG. 1.

[0011] FIG. 4A, FIG. 4B and FIG. 4C are a diagram for explaining loops formed by a second warp in the industrial fabric.

[0012] FIG. 5 is a diagram for explaining a small loop formed by the first warp.

DETAILED DESCRIPTION OF THE INVENTION

[0013] The invention will now be described by reference to the preferred embodiments. This does not intend to limit the scope of the present invention, but to exemplify the invention. In the following explanation, warps are threads extending along the direction of conveyance of paper materials, and wefts are threads extending in a direction that intersects the warps, when a multilayer weave for papermaking constitutes an endless belt. Further, an upper surface side means to be located on the side where the materials are conveyed out of the two sides of a belt for nonwoven fabrics, and a lower surface side means to be located mainly on the side where a drive roller is in contact out of the two sides of the belt for nonwoven fabrics. An obverse surface is a surface exposed on the upper surface side or the lower surface side.

[0014] Further, the term design diagram represents the minimum repeating unit of a weave texture and corresponds to a weave repeat of the weave. In other words, a weave repeat is repeated from front to back and left to right to form a weave. Further, knuckles refers to parts where a warp is exposed on the obverse surface after passing above or below a single or multiple wefts.

[0015] FIG. 1 is a design diagram showing a weave repeat of an industrial fabric 10 according to an exemplary embodiment. FIG. 2 is a cross-sectional view in the warp direction along warps of the industrial fabric 10 shown in FIG. 1. FIG. 2A shows a cross-section of a first warp pair composed of a first warp 1f and a first warp 2f, and FIG. 2B shows a cross-section of a second warp pair composed of a second warp 3s and a second warp 4s.

[0016] In the design diagram, warps are indicated by Arabic numerals, e.g., 1, 2, 3, and so on. Wefts are indicated by Arabic numerals with dashes, e.g., 1, 2, 3, and so on. The first warps and the first wefts are indicated by numbers with f, and the second warps and the second wefts are indicated by numbers with s.

[0017] In the design diagram, x marks indicate that the first and second warps are arranged above the first and second wefts, and unmarked squares indicate that the first and second warps are arranged below the first and second wefts.

[0018] An industrial fabric 10 shown in FIG. 1 includes first warps (1f, 2f, 5f, and 6f), second warps (3s, 4s, 7s, and 8s), first wefts (1f, 3f, 5f, and 7f), and second wefts (2s, 4s, 6s, and 8s). In a weave repeat that forms a repeating pattern of the industrial fabric 10, there are eight warps: the first warps (1f, 2f, 5f, and 6f); and the second warps (3s, 4s, 7s, and 8s), and there are eight wefts: the first wefts (1f, 3f, 5f, and 7f); and the second wefts (2s, 4s, 6s, and 8s).

[0019] The first wefts (1f, 3f, 5f, and 7f) may have a larger wire diameter than the second wefts (2s, 4s, 6s, and 8s) and be set to, for example, a size that is 1.5 to 3 times the wire diameter of the second wefts (2s, 4s, 6s, and 8s). In the weave repeat, there are four first warps (1f, 2f, 5f, and 6f), there are four second warps (3s, 4s, 7s, and 8s), there are four first wefts (1f, 3f, 5f, and 7f), and there are four second wefts (2s, 4s, 6s, and 8s). The relationship between the first and second wefts will be explained now with reference to FIG. 3.

[0020] FIG. 3 is a cross-sectional view along a first warp 1f of the industrial fabric 10 shown in FIG. 1. The first wefts (1f, 3f, 5f, and 7f) and the second wefts (2s, 4s, 6s, and 8s) are arranged alternately. This allows the second wefts to be arranged between the first wefts, which have a large wire diameter, so as to function as floating yarns.

[0021] The first wefts (1f, 3f, 5f, and 7f) and the second wefts (2s, 4s, 6s, and 8s) are provided while being shifted from each other in the warp direction. The first weft 1f and the second weft 2s are spaced apart from each other in the warp direction by a gap C, and the other first and second wefts also have the same gap C. The gap C between the first and second wefts serves as a space for weaving the first warp and the second warp around the first weft that serves as the axis.

[0022] The second wefts (2s, 4s, 6s, and 8s) are located on the upper side of the industrial fabric 10. A line L2 passing through the center of the plurality of second wefts (2s, 4s, 6s, and 8s) is located on the upper side of a line L1 passing through the center of the plurality of first wefts (1f, 3f, 5f, and 7f). This allows the second wefts (2s, 4s, 6s, and 8s) to function as floating yarns.

[0023] The description now returns to FIG. 1 and FIG. 2. The first warps (1f, 2f, 5f, and 6f) are woven only into the first wefts (1f, 3f, 5f, and 7f). The first warps are not woven into the second wefts and prevent the second wefts from being pulled to the lower surface side. The second warps (3s, 4s, 7s, and 8s) are woven into the first wefts (1f, 3f, 5f, and 7f) and the second wefts (2s, 4s, 6s, and 8s). The second warps are also woven into the second wefts, tying the second wefts to the first wefts.

[0024] The first warps (1f, 2f, 5f, and 6f) have a weaving pattern of passing below all the second wefts (2s, 4s, 6s, and 8s) and alternately going above and below the first wefts (1f, 3f, 5f, and 7f). This allows the first warps to be finely woven only into the first wefts.

[0025] A pair of first warps (1f and 2f) are adjacent to each other in the weft direction to form a first warp pair. The other pair of first warps (5f and 6f) are adjacent to each other in the weft direction to form a first warp pair in the same manner. The adjacent first warps (1f and 2f, and 5f and 6f) forming the first warp pairs are woven into the first wefts (1f, 3f, 5f, and 7f) while being shifted from each other by one first weft with respect to the first wefts in the warp direction. The first warps (1f, 2f, 5f, and 6f) form a weaving pattern of being woven into the first wefts (1f, 3f, 5f, and 7f) while alternately going above and below the first wefts. As shown in FIG. 2A, this allows a pair of first warps to be woven into the first wefts so as to sandwich the first wefts from above and below, and the second wefts are arranged to float on the upper surface side by the pair of first warps. The arrangement of the second wefts as floating yarns between the first wefts with a thick wire diameter makes the mesh of the industrial fabric 10 finer and suppresses the sticking-in of nonwoven fabric fibers.

[0026] In a weave repeat that forms a repeating pattern of the industrial fabric 10, the weaving pattern of one first warp pair (1f and 2f) and the weaving pattern of the other first warp pair (5f and 6f) are identical. More specifically, the weaving pattern of the first warp 1f and the weaving pattern of the first warp 5f are identical, and the weaving pattern of the first warp 2f and the weaving pattern of the first warp 6f are identical. Having the identical weaving patterns means that the first wefts into which the first warps are woven are the same.

[0027] A pair of second warps (3s and 4s) are adjacent to each other in the weft direction to form a second warp pair. The other pair of second warps (7s and 8s) are adjacent to each other in the weft direction to form a second warp pair in the same manner. The pairs of second warps (3s and 4s, and 7s and 8s) forming the second warp pairs are woven into the second wefts (2s, 4s, 6s, and 8s) in the warp direction while being shifted from each other by two second wefts with respect to the second wefts in the warp direction. In other words, the second warp 3s is woven so as to pass over the second weft 2s, and the second warp 4s is woven so as to pass over the second weft 6s. Thus, the weaving pattern of the second warp 3s and the weaving pattern of second warp 4s are shifted by two second wefts with respect to the second wefts.

[0028] The second warp 3s forms a weaving pattern of passing above one first weft 1f, one second weft 2s, and one first weft 3f in order and then passing below one second weft 4s, one first weft 5f, one second weft 6s, one first weft 7f, and one second weft 8s in order. Each of the other second warps (4s, 7s, and 8s) forms a weaving pattern of passing above one first weft, one second weft, and one first weft in order and then passing below one second weft, one first weft, one second weft, one first weft, and one second weft in order. In other words, each of the second warps (3s, 4s, 7s, and 8s) forms a common weaving pattern.

[0029] In a weave repeat that forms a repeating pattern of the industrial fabric 10, two second warp pairs (3s and 4s, and 7s and 8s) have a common weaving pattern. One second warp pair (3s and 4s) and the other second warp pair (7s and 8s) form a weaving pattern of being shifted from each other by one weft in the warp direction with respect to the first or second wefts. The second warp 3s and the second warp 7s are provided while being shifted from each other by one first weft with respect to the first wefts, and the second warp 4s and second warp 8s are provided while being shifted from each other by one first weft with respect to the first wefts. Thus, the two second warp pairs (3s and 4s, and 7s and 8s) share the same weaving pattern but are provided while being shifted from each other in the warp direction. This allows the first wefts and the second wefts to be woven evenly.

[0030] The first wefts (1f, 2f, 5f, and 6f) and the second wefts (3s, 4s, 7s, and 8s) are provided while being shifted from each other in the weft direction. For example, although the first warp 2f may come into contact with the second warp 3s in the weft direction, the warps are arranged so as not to overlap in the weft direction since the warps are both woven into the first weft 1f. The first warps (1f, 2f, 5f, and 6f) are also provided while being shifted from each other in the weft direction, and the second warps (3s, 4s, 7s, and 8s) are also provided while being shifted from each other in the weft direction. As a result, the eight warps are arranged side by side in the weft direction.

[0031] The first warp pairs (1f and 2f, and 5f and 6f) and the second warp pairs (3s and 4s, and 7s and 8s) are arranged alternately in the weft direction. By arranging the first warp pairs alternately one set at a time, spaces created between the warps and the wefts can be made uniform.

[0032] The density of the first wefts (1f, 2f, 5f, and 6f) and the density of the second wefts (3s, 4s, 7s, and 8s) are in the range of 90 percent to 140 percent. Since the density DW of the warps is large, the mesh (gaps) of the industrial fabric 10 are small, and the sticking-in of the fibers of the nonwoven fabric are less likely to occur, thus resulting in good releasability. This density DW of the warps is calculated by the following Expression 1.

[00001]$\begin{array}{cc}\mathrm{DW}=\left(DM/25.4\right)100& \mathrm{Expression}1\end{array}$

[0033] DW represents the warp density, D represents the diameter (in millimeters) of the warps, and M indicates a mesh count, which refers to the number of warps per inch. The diameter of the first warps and the diameter of the second warps may be the same.

[0034] Resin may be applied to the upper surface of the industrial fabric 10 to improve gripping force. For example, if the gripping force of the industrial fabric 10 is small, a nonwoven sheet to be formed may be folded due to the movement of the nonwoven sheet on the industrial fabric 10 at the time of the conveyance of the nonwoven sheet on the industrial fabric 10, which may lead to a decrease in the quality rate of nonwoven fabrics. Applying resin to the industrial fabric 10 improves the gripping force of the industrial fabric 10. Since the peak of a knuckle of a first warp is located on the inner side of the industrial fabric 10 than the peak of a second warp, when resin is applied to the industrial fabric 10, the resin attached to the peak of the knuckle of the first warp is less likely to come into contact with the press rolls or the like of a nonwoven manufacturing device, and even if the resin attached to the peak of the knuckle of the second warp peels off, it is possible to prevent peeling of all the resin throughout the entire industrial fabric 10.

[0035] At least some of the second warps (3s, 4s, 7s, and 8s) are conductive carbon yarns. All of the second warps (3s, 4s, 7s, and 8s) may be conductive carbon yarns. By weaving conductive carbon yarns into the industrial fabric 10, the industrial fabric 10 can be provided with a static electricity removing property. If static electricity is charged on the industrial fabric 10, the industrial fabric 10 and the nonwoven web may repel each other, making it impossible to form a good nonwoven fabric.

[0036] FIG. 4 is a diagram for explaining loops formed by a second warp in the industrial fabric 10. FIG. 4A shows a first loop 20a, FIG. 4B shows a second loop 20b, and FIG. 4C shows a third loop 20c. When the first loop 20a, the second loop 20b, and the third loop 20c are not to be distinguished, the loops are simply referred to as loops 20.

[0037] A loop 20 is formed by folding back a warp and forms a space for passing a first weft having a large wire diameter. When attaching the industrial fabric 10 to the nonwoven fabric manufacturing device, the operator wraps the industrial fabric 10 around a plurality of rolls and connects the two ends of the industrial fabric 10 so as to form an endless belt. When connecting the ends of the industrial fabric 10, the operator inserts a weft for looping into the loop 20. The weft for looping may have the same wire diameter as that of the first weft or may have a smaller wire than that of the first weft.

[0038] In FIG. 4, wefts for looping that are inserted into loops 20 are shown in black. If the shape of a loop 20 varies, it becomes difficult to insert a weft for looping, and the weft for looping is likely to get caught on the loop 20 when being inserted. The width of the industrial fabric 10 can be several meters or more, and when inserting a weft for looping having that length, it is desirable for the loop 20 to be well-shaped. Furthermore, when the weft for looping is inserted into the loop 20, the weft may get caught in the loop 20, causing the loop 20 to shift or tilt, resulting in differences in the breathability of the fabric in some parts.

[0039] The first loop 20a shown in FIG. 4A forms a large loop that allows two wefts for looping (5r and 7r) to pass through using the second warp 3s. Further, the second loop 20b shown in FIG. 4B forms a large loop that allows the two wefts for looping (5r and 7r) to pass through using the second warp 4s. The weft 1f located on the right side of the first loop 20a shown in FIG. 4A is a weft for looping and is woven by folding a warp that is not shown. The weft 3f located on the left side of the second loop 20b shown in FIG. 4B is a weft for looping and is woven by folding a warp that is not shown.

[0040] The third loop 20c shown in FIG. 4C forms a small loop that allows one weft for looping to pass through using the second warp 7s and the second warp 8s. The weft 5r for looping is inserted into the third loop 20c formed by the second warp 7s, and the weft 7r for looping is inserted into the third loop 20c formed by the second warp 8s. The loops 20 shown in FIGS. 4A to 4C are arranged in order along the weft direction. This connects both ends of the industrial fabric 10.

[0041] FIG. 5 is a diagram for explaining a small loop 22 formed by a first warp. The first warp 1f is folded back to form the small loop 22. One weft 5r for looping is inserted into the small loop 22. The first warp 1f is folded back and woven as the first warp 2f.

[0042] If the loop is formed by a warp into which only a second weft is woven, the position of the loop will be at a height that matches the second weft located on the upper surface side, and the loop will be formed protruding above the height of the first weft on the upper surface side. In the industrial fabric 10, since all the warps are woven into the first wefts with a large wire diameter, the loops 20 and the small loop 22 are all arranged to match the height of the first wefts, thus allowing the industrial fabric 10 to be formed well with less variation in position and shape of the loops 20. The stabilization of the shape of the loops 20 makes it easier to insert the wefts for looping and facilitates the process of joining the two ends of the industrial fabric 10. Further, the wefts for looping are less likely to get caught on the loops 20 when being inserted, which makes it possible to suppress the shifting or tilting of the loops 20, and the formation of marks resulting from the loops 20 on a nonwoven fabric placed on the loop 20 portion can thus be suppressed. The stabilization of the shape of the loops 20 makes it possible to form large loops.

[0043] As shown in FIGS. 4A to 4C, the industrial fabric 10 has both a large loop into which two wefts for looping can be inserted and a small loop into which one weft for looping can be inserted but is not limited to this form. For example, the industrial fabric 10 may have only a large loop into which two wefts for looping can be inserted or only a small loop into which one weft for looping can be inserted.

[0044] In the industrial fabric 10, the first and second warps are arranged in a row of two warps each. Therefore, a loop 20 can be formed, for example, by folding back the second warp 3s and weaving the second warp 3s into the adjacent second warp 4s.

[0045] Since the weaving patterns of the two first warp pairs are identical, i.e., the weaving pattern of the first warp 1f and the weaving pattern of the first warp 5f are identical and the weaving pattern of the first warp 2f and the weaving pattern of the first warp 6f are identical, the inclination direction of the loops can be aligned, making it easier to insert the wefts for looping.

[0046] An industrial fabric according to each of the above exemplary embodiments may be subjected to the following processing. For example, in order to improve the surface smoothness, the obverse surface side of the industrial fabric may be polished in the range of 0.02 to 0.05 mm. In particular, the obverse surface side may be polished by 0.02 mm or 0.03 mm.

[0047] Further, in order to suppress the fraying of yarns at a mesh (industrial fabric) edge, the mesh may be reinforced by coating with a polyurethane resin in the range of 5 mm to 30 mm, particularly in the range of 5 mm, 10 mm, or 20 mm, from the mesh edge. The coating of the mesh edge may be applied on one or both sides. The resin may be hot melt polyurethane and may be conductive.

[0048] In order to improve the wear resistance of a mesh edge, the mesh may be coated in the range of 20 mm to 500 mm (particularly 25, 50, 75, 100, 150, 250, 300, 350, or 400 mm) from the mesh edge with three to sixteen (particularly three, four, seven, eight, ten, twelve, fifteen, or sixteen) strips of resin of a width of about 7 mm over the entire length. The plurality of above-mentioned strips of polyurethane resin may be applied to both edges of the mesh or only to one side. The resin may be hot melt polyurethane.

[0049] The following is a list of preferred element ranges for an industrial fabric. The wire diameter of warps is preferably 0.10 mm to 1.0 mm, more preferably 0.2 mm to 0.6 mm, and particularly preferably 0.3 mm to 0.5 mm, where the warps include the first warps and the second warps. The diameter of the warps may be the same. The wire diameter of the wefts is preferably 0.10 mm to 1.2 mm, more preferably 0.2 mm to 1.0 mm, and particularly preferably 0.4 mm to 0.9 mm.

[0050] The second wefts may be composed of only PET wires or only polyamide wires, may be alternately interwoven PET and polyamide wires, or may be conductive carbon yarns. The first wefts may be composed of only PET wires, only polyamide wires, or alternately interwoven PET and polyamide wires, or may be conductive carbon yarns. Also, in order to reduce the driving load of the machine, low-friction yarns may be woven with the first wefts.

[0051] The air permeability is preferably 100 cm.sup.3/cm.sup.2/s to 600 cm.sup.3/cm.sup.2/s and more preferably 200 cm.sup.3/cm.sup.2/s to 400 cm.sup.3/cm.sup.2/s.

[0052] The mesh thickness is preferably 0.3 mm to 3.0 mm, more preferably 0.5 mm to 2.5 mm, and particularly preferably 1.0 mm to 2.5 mm. The usage applications mainly include usage as a nonwoven fabric belt and particularly as a spunbond nonwoven fabric conveying belt.

[0053] The cross-sectional shape of the warps and wefts according to each of the above-mentioned exemplary embodiments is not limited to a circular shape, and yarns having a quadrangular shape, a star shape, etc., and yarns having an elliptical shape, a hollow shape, a sheath-core structure shape, etc., can be used. In particular, by making the cross-sectional shape of the warps have a square shape, a rectangular shape, or an elliptical shape, the cross-sectional area of the yarns can be increased, and elongation resistance and rigidity can thus be improved. The cross-sectional shape of the second wefts being elliptical or rectangular reduces voids on the obverse surface of the industrial fabric 10 compared to a circular shape and thus allows for the suppression of the sticking of nonwoven fibers into the obverse surface of the industrial fabric 10.

[0054] Further, the yarn material can be freely selected as long as the yarn satisfies the desired characteristics, and polyethylene terephthalate, polyester, polyamide, polyphenylene sulfide, polyvinylidene fluoride, polypropylene, aramid, polyether ether ketone, polyethylene naphthalate, polytetrafluoroethylene, cotton, wool, metals, thermoplastic polyurethane, thermoplastic elastomers, etc., can be used. Needless to say, yarns prepared from a copolymer and yarns prepared by blending or adding various substances to such a material may be used according to the purpose. In general, polyester monofilaments having rigidity and excellent dimensional stability are preferably used as yarns constituting industrial fabrics.

INDUSTRIAL APPLICABILITY

[0055] The present invention relates to industrial fabrics used for producing non-woven fabrics.

REFERENCE SIGNS LIST

[0056] 1f first warp, lf first weft, 2f first warp, 2s second weft, 3s second warp, 3f first weft, 4s second warp, 4s second weft, 5f first warp, 5f first weft, 6f first warp, 6s second weft, 7s second warp, 7f first weft, 8s second warp, 8s second weft, 10 industrial fabric, 20a first loop, 20b second loop, 20c third loop