Industrial fabric, support for manufacturing nonwoven fabric, and manufacturing method of nonwoven fabric

Abstract

To provide an industrial fabric having a knuckle portion higher and steeper than the other parts and capable of imparting a vivid pattern to a nonwoven fabric by the knuckle portion.SOLUTION: In an industrial fabric having warp yarns and weft yarns, the warp yarns contain a warp yarn A group consisting of n warp yarns and warp yarns B, and the warp yarns of the warp yarn A group are arranged in the order of a warp yarn A1, a warp yarn A2, ...and a warp yarn An with the warp yarns B interposed therebetween; and the weft yarns contain a weft yarn X group consisting of n weft yarns and weft yarns Y, and the weft yarns of the weft yarn X group are arranged in the order of a weft yarn X1, a weft yarn X2, ...and a weft yarn Xn with the weft yarns Y interposed therebetween. In the warp yarn A group, a warp yarn Am passes over a weft yarn Xm and then passes under the weft yarn Y and all the weft yarns constituting the weft yarn X group other than the weft yarn Xm. The warp yarn B passes under the weft yarn X group and passes over the weft yarn Y, and the warp yarns of the warp yarn A group pass over the weft yarns of the weft yarn X group. In a knuckle portion formed by such a manner, when a cross section in the warp yarn direction is observed, the warp yarns are in contact with 40% or more of the outer circumference of the weft yarns.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to industrial fabrics used in the manufacturing process of nonwoven fabrics, paper, etc., and more particularly to a support for nonwoven fabric manufacturing on which a fibrous web is placed when manufacturing nonwoven fabrics, and a method for manufacturing nonwoven fabrics using the support. [Background technology]

[0002] In the production of nonwoven fabrics, a fiber web is placed on a support for nonwoven fabric production (hereinafter simply referred to as "support") and subjected to a process of entangling and integrating the fibers. It is known that by appropriately selecting the configuration of the support, a pattern corresponding to the configuration of the support can be imparted to the surface of the nonwoven fabric, more specifically, to the surface of the nonwoven fabric that is in contact with the support. Various supports have been proposed for imparting desired patterns to nonwoven fabrics. For example, Patent Document 1 proposes a nonwoven fabric-forming belt having pattern-imparting protrusions arranged on the forming-side surface of the belt body. Patent Document 2 proposes a textured woven fabric formed from warp and weft yarns, in which at least one surface of the fabric is formed by a. a first pattern region consisting of a structure in which the warp yarns pass over continuous weft yarns to form long crimps (also referred to as "floats" or simply "floats") on the surface, and b. a second pattern region consisting of a structure in which the weft yarns pass over continuous warp yarns to form long crimps on the surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-327255 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-9013 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure relates to an industrial fabric, and provides an industrial fabric in which knuckle portions are formed on one surface by a "float" where specific warp yarns pass over weft yarns, and the knuckle portions are higher than other portions on the one surface and have a steep height change, making it possible to produce various nonwoven fabrics with clearly defined patterns using the knuckle portions. [Means for solving the problem]

[0005] The industrial fabric of the present disclosure is an industrial fabric having warp yarns and weft yarns, An industrial fabric having warp yarns and weft yarns, The warp yarns are n (where n is a positive natural number) warp yarns (warp yarn A1, warp yarn A2, ... warp yarn A n The warp threads constituting the warp thread group A and the warp thread B are arranged alternately, and the warp threads constituting the warp thread group A are arranged in a manner such that the warp thread A1, the warp thread A2, and the warp thread B are sandwiched between them. 2、 Warp A n are arranged in the order of The weft yarns are n weft yarns (weft yarn X1, weft yarn X2, ... weft yarn X n The wefts constituting the weft X group and the weft B are arranged alternately, and the wefts constituting the weft X group are arranged in the order of weft X1, weft X2, ..., weft X, with the weft Y sandwiched between them. n are arranged in the order of In the warp yarn A group, the warp yarn A m (1≦m≦n, n≧2, where m is a positive natural number) is the weft X m (1≦m≦n, n≧2 where m is a positive natural number) and warp thread A passes over m Weft X m Form a float for the weft Y and weft X m Passing under all the wefts constituting the group X except for the warp thread A m Weft Y and Weft X m It forms a sinking for all wefts constituting the weft group X other than The warp yarn B passes under the weft yarn X group and over the weft yarn Y, When a cross section in the warp direction is observed at a knuckle portion formed by passing a warp belonging to the warp yarn group A over a weft constituting the weft yarn group X, the warp yarn contacts 40% or more of the outer periphery of the weft yarn. It is an industrial fabric. [Effects of the Invention]

[0006] The industrial fabric of the present disclosure is an industrial fabric having warp yarns and weft yarns, and forms a group of warp yarns woven together so that certain warp yarns form floats relative to certain weft yarns and sink relative to other certain weft yarns, and the height of the knuckle portions formed by the floats is not only higher on the surface on which the knuckle portions are formed than in other parts, but the knuckle portions are also steep, in other words, on the surface of the industrial fabric on the side having the knuckle portions, the knuckle portions are formed as convex portions where the thickness of the industrial fabric changes abruptly. When an industrial fabric having such knuckle portions is used as a support for producing a nonwoven fabric, it becomes possible to more clearly apply a pattern corresponding to the height and arrangement of the knuckle portions to the nonwoven fabric. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing an example of a weave of an industrial fabric according to the present embodiment. [Figure 2] 1 is a photomicrograph showing a cross section in the warp direction of an example of an industrial woven fabric according to the present embodiment. [Figure 3] 10 is a weave diagram of another example of the industrial fabric of the present embodiment. [Figure 4] FIG. 2 is a cross-sectional view in the warp direction illustrating a method for measuring the angle indicating the steepness of the knuckle portion in the industrial woven fabric of the present embodiment. [Figure 5] 1 is a photograph of the surface of the nonwoven fabric produced in Example 1. [Figure 6] 1 is a photograph of the surface of the nonwoven fabric produced in Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0008] Supports used to impart patterns to the surfaces of various nonwoven fabrics, such as staple fiber nonwoven fabrics including spunlace nonwoven fabrics (also called hydroentangled nonwoven fabrics) and air-through nonwoven fabrics (also called thermally bonded nonwoven fabrics or heat-bonded nonwoven fabrics), and long fiber nonwoven fabrics such as spunbond nonwoven fabrics and meltblown nonwoven fabrics, have irregularities on the surface of the support on which the nonwoven fabric or a fiber assembly such as a fiber web (a precursor to the nonwoven fabric) is placed, corresponding to the pattern to be imparted to the nonwoven fabric, and the height of the convex parts is made higher than the support surface surrounding the convex parts, making it possible to impart a pattern to the nonwoven fabric or fiber assembly. In Patent Document 1, the convex parts correspond to pattern-imparting protrusions, and in Patent Document 2, they correspond to second pattern regions consisting of a structure that forms long crimps of weft yarns passing over warp yarns that are continuous on the surface of the fabric.

[0009] The inventors have investigated the configuration of an industrial fabric that does not require the provision of separate protrusions, and that can form clear patterns on the surface of a nonwoven fabric or fiber assembly, even when a relatively small pattern (in other words, a pattern in which the area of ​​the convex or concave portions that make up the pattern is small and can be seen when the surface of the manufactured nonwoven fabric is observed from the vertical direction (or thickness direction)) is formed on the nonwoven fabric, using the knuckle portions formed when one to several warp threads pass over the weft threads as the convex portions for forming the pattern.

[0010] Therefore, the inventors adopted a specific weave and made the warp yarns easy to bend, so that in the knuckle portion formed by the specific warp yarns passing over the weft yarns, the specific warp yarns contact 40% or more of the circumference of the weft yarns, forming a knuckle portion on the surface of an industrial woven fabric. As a result, the surface of the support on which the knuckle portion is provided is not only higher than the surface of the support surrounding the knuckle portion, but also the knuckle portion is steep, in other words, the height (apparent thickness) of the knuckle portion increases rapidly relative to the surface of the support surrounding the knuckle portion.

[0011] In the knuckle portion formed by weaving such a support, the warp yarns are deformed so as to fit closely to the weft yarns contained in the knuckle portion. Therefore, the knuckle portion does not have a gradual, smooth change in height (apparent thickness), but rather has a sharp convex portion with abrupt changes in height, and abrupt changes in height (apparent thickness) occur between the knuckle portion and the surrounding support surface. By transferring the shape of these convex portions to the surface of a fiber assembly such as a nonwoven fabric or fiber web, unevenness with abrupt changes in height (apparent thickness) is also formed on the surface of the nonwoven fabric. Because the unevenness has abrupt changes in height (apparent thickness), the changes are easily visible, making the outline of the pattern clearer. As a result, a clear pattern can be imparted to the surface of a fiber assembly such as a nonwoven fabric or fiber web. The configuration of the industrial woven fabric (hereinafter sometimes simply referred to as "woven fabric") of this embodiment will be described below.

[0012] The industrial fabric of this embodiment is an industrial fabric having warp yarns and weft yarns, An industrial fabric having warp yarns and weft yarns, The warp yarns are n (where n is a positive natural number) warp yarns (warp yarn A1, warp yarn A2, ... warp yarn A n The warp threads constituting the warp thread group A and the warp thread B are arranged alternately, and the warp threads constituting the warp thread group A are arranged in a manner such that the warp thread A1, the warp thread A2, and the warp thread B are sandwiched between them. 2、 Warp A n are arranged in the order of The weft yarns are n weft yarns (weft yarn X1, weft yarn X2, ... weft yarn X n The wefts constituting the weft X group and the weft B are arranged alternately, and the wefts constituting the weft X group are arranged in the order of weft X1, weft X2, ..., weft X, with the weft Y sandwiched between them. n are arranged in the order of In the warp yarn A group, the warp yarn A m (1≦m≦n, n≧2, where m is a positive natural number) is the weft X m (1≦m≦n, n≧2 where m is a positive natural number) and warp thread A passes over m Weft X mForm a float for the weft Y and weft X m Passing under all the wefts constituting the group X except for the warp thread A m Weft Y and Weft X m It forms a sinking for all wefts constituting the weft group X other than The warp yarn B passes under the weft yarn X group and over the weft yarn Y, When a cross section in the warp direction is observed at a knuckle portion formed by passing a warp belonging to the warp yarn group A over a weft constituting the weft yarn group X, the warp yarn contacts 40% or more of the outer periphery of the weft yarn. It is an industrial fabric.

[0013] FIG. 1 shows a weave structure of an embodiment in which n is 2. The warp thread group A consists of warp threads A1 and A2, and the weft thread group X consists of weft threads X1 and X2. The warp thread group A is arranged in the order of warp thread A1 and warp thread A2, with warp thread B sandwiched between two warp threads A, and the weft thread group X is arranged in the order of weft thread X1 and weft thread X2, with weft thread Y sandwiched between two weft threads X. In FIG. 1 (and drawings showing weave structures other than FIG. 1), the areas shaded in black correspond to the areas where the warp threads of the warp thread group A pass over the wefts of the weft thread group X to form the knuckle portion. In the weave structure of FIG. 1, in relation to the weft thread group X, the warp thread A1 passes over the weft thread X1 to form the knuckle portion, then passes under the weft thread X2, and then passes over X1 again. In the weave of the industrial woven fabric of the present invention, wefts belonging to weft group X and weft Y are arranged alternately, so that warp thread A1 passes over weft thread X1 to form a knuckle, then passes under weft thread Y adjacent to weft thread X1, then passes under weft thread X2 and weft thread Y, and then passes over weft thread X1 again. Therefore, warp thread A1 passes over three wefts on the surface opposite to the surface shown in Figure 1, forming a long crimp spanning multiple wefts.

[0014] Similarly, in relation to weft yarn group X, warp yarn A2 passes over weft yarn X2, then passes under weft yarn X1, and passes over X2 again. In the weave of the industrial woven fabric of the present invention, weft yarns belonging to weft yarn group X and weft yarn Y are arranged alternately, so warp yarn A2, like warp yarn A1, passes over weft yarn X2 to form a knuckle, then passes under weft yarn Y adjacent to weft yarn X1, then passes under weft yarn X1 and weft yarn Y, and passes over weft yarn X2 again. Therefore, warp yarn A2 also passes over three wefts on the surface opposite to the surface shown in FIG. 1, forming a long crimp spanning the three wefts. Warp thread B alternately passes under weft threads belonging to weft thread group X (i.e., weft thread X1, weft thread X2, etc.) and over weft thread Y. In Figure 1, the part where warp thread B passes over weft thread Y is shown in gray.

[0015] In this embodiment, at least some of the warp threads constituting warp thread group A have a property of easily bending or flexing in the thickness direction of the weave. Therefore, in a knuckle portion formed when a warp thread of warp thread group A having this property passes over a weft thread of weft thread group X, the warp thread contacts 40% or more of the outer periphery of the weft thread. As shown in FIG. 2, such a knuckle portion is located at a higher position on the surface of the woven fabric where the knuckle portion exists compared to other surface portions. In addition, since the warp threads are deformed along the cross-sectional shape of the weft thread, the convex portion (knuckle portion) formed when the warp thread passes over the weft thread is formed as a steep convex portion rather than a gentle slope. Furthermore, in this embodiment, the weft thread X m In the length direction (also called the CD direction or width direction of the weave), a knuckle portion is formed. m and weft X m Adjacent to the intersection of weft X m and warp thread B cross at weft thread X m There is a weave structure in which warp thread B passes under this, and this structure is also thought to make the knuckle part steeper.

[0016] At the knuckle portion, the warp yarns may contact 40% to 80% of the circumference of the weft yarns, particularly 50% to 75%, more particularly 55% to 75%, and even more particularly 60% to 70%.

[0017] As described above, at least some of the warp yarns constituting warp yarn group A have the property of easily bending or bending in the thickness direction of the weave. Warp yarns with such a property may be, for example, monofilaments having a horizontally elongated cross section when cut perpendicular to the longitudinal direction. When a monofilament having a horizontally elongated cross section (hereinafter referred to as a "flat monofilament") is used as a warp yarn by aligning its horizontal direction, i.e., its major axis or the long side of the rectangle circumscribing the cross section, parallel to the weft direction, it easily bends or bends in the warp direction and is likely to come into contact with the outer peripheral surface of the weft yarn over a longer distance along the outer peripheral surface of the weft yarn.

[0018] The cross-sectional shape of the flat filaments may be rectangular, oblong, rectangular with rounded corners, or rugby ball-shaped. The flatness of the flat filaments is determined by the ratio of the short side dimension to the long side dimension of the rectangle circumscribing the cross-section (aspect ratio). The aspect ratio of the flat filaments may be, for example, 1:1.1 to 1:5, 1:1.2 to 1:4, 1:1.3 to 1:3, 1:1.4 to 1:2.5, or 1:1.6 to 1:2.6. In particular, the ratio may be 1:1.5 to 1:2.0. For the same cross-sectional area, the larger the aspect ratio (i.e., the longer the horizontal length), the more easily the flat filaments will bend or flex in the thickness direction of the weave when combined with weft yarns to form a woven fabric. If the aspect ratio is too large, the breathability of the woven fabric will decrease. For example, when used as a support for entangling fibers with a high-pressure fluid flow, the high-pressure fluid flow will be less likely to pass through to the back side of the support, making it difficult to produce a nonwoven fabric.

[0019] Alternatively, to form the knuckle portion, the warps constituting warp thread group A and the wefts constituting weft thread group X may be monofilaments made of the same material, with at least some of the warps constituting warp thread group A having a diameter that is between 40% and 80% of the diameter of the wefts constituting weft thread group X. The smaller the diameter of monofilaments made of the same material, the more easily they bend or flex in the thickness direction of the weave when combined with weft threads to form a weave. Therefore, using warps with a small diameter makes it easier for the warps to contact the wefts over a longer distance along the outer periphery of the wefts at the knuckle portion. The diameter of the warps forming the knuckle portion may be between 45% and 75% of the diameter of the weft, and particularly between 50% and 70%.

[0020] Here, when either or both of the warp and weft yarns have a non-circular cross section, the diameter of the warp and weft yarns is the diameter of a circle having the same cross section.

[0021] Of the warp threads in group A, the flat monofilament or the warp thread with a smaller diameter than the weft threads in group X of weft threads may be, for example, one of the two warp threads in group A in the example shown in Figure 1, or may be all of the warp threads in group A. By making all of the warp threads in group A flat monofilaments or monofilaments with a smaller diameter, all of the areas where the warp threads in group A pass over the weft threads in group X of weft threads become knuckle portions suitable for forming patterns in the nonwoven fabric.

[0022] Warp yarn B may also be a flat monofilament or a warp yarn having a smaller diameter than the weft yarns of weft yarn group X. Furthermore, the warp yarns of warp yarn group A and warp yarn B may all be the same monofilament, in which case it is possible to avoid the need to change the type of warp yarn depending on the warp position, making it easier to produce the woven fabric and making the surface of the woven fabric uniform throughout.

[0023] When warp threads A and B are the same type of flat monofilament, the flat monofilament may be, for example, a monofilament circumscribing a cross section of a rectangle having a short side of 0.2 mm to 0.8 mm and a long side of 0.3 mm to 1.2 mm. The short side of the circumscribing rectangle may be 0.25 mm to 0.7 mm, particularly 0.28 mm to 0.6 mm, and the long side may be 0.4 mm to 1.1 mm, particularly 0.5 mm to 1.0 mm. When the weft is a monofilament having a circular cross section, the flat monofilament constituting the warp may have a long side that is 0.6 to 1.2 times the diameter of the weft.

[0024] The weft yarns X group and the weft yarn Y may be monofilaments having a circular cross section, for example. The weft yarns X group and the weft yarn Y may be monofilaments having the same diameter. In this case, the diameter of the monofilaments forming the weft yarns X group and the weft yarn Y may be, for example, 0.3 mm to 1.2 mm, particularly 0.4 mm to 1.0 mm. The diameter of the weft yarns of the weft yarns X group may be larger than the diameter of the weft yarn Y. By increasing the diameter of the weft yarns X group, the knuckle portion can be made higher and steeper. For example, when the diameter of the weft yarn Y is 0.3 mm to 1.2 mm, the diameter of the weft yarns of the weft yarns X group may be larger than the diameter of the weft yarn Y, for example, 0.05 mm to 0.8 mm, particularly 0.08 mm to 0.6 mm, and more particularly 0.1 mm to 0.5 mm.

[0025] The warp and weft threads constituting the support may be made of one or more materials selected from polyester, polyamide, polyolefin, polyether ether ketone, polyphenylene sulfide, and the like. The warp and weft yarns may be in a form other than monofilament, for example, multifilament or spun yarn. In the case of multifilament or the like, the fineness may be used instead of the diameter as an index of the thickness of the yarn.

[0026] When the weft yarns of the weft yarn group X are multifilament or spun yarns, it can be difficult to determine the percentage of the warp yarns of the warp yarn group A that contact the outer periphery of the weft yarns at the knuckle section formed by passing over the weft yarns of the weft yarn group X. In this case, as shown in Figure 4, the angle (acute angle) α formed by the tangent of the warp yarn 1 of the warp yarn group A with the horizontal plane 3 is measured at the point where the warp yarn 1 of the warp yarn group A intersects with the adjacent warp yarn 2 of the warp yarn group A in the warp direction cross section of the knuckle section. If this angle is 50 degrees or more, particularly 60 degrees or more, it corresponds to the industrial fabric of this embodiment. The angle becomes larger as the warp yarns are arranged more closely to the weft yarns. This angle measurement is also useful when both the warp and weft yarns are monofilament, as shown in Figure 2, or when the warp yarns of the warp yarn group A are multifilament or spun yarns. There is no particular upper limit to the angle (acute angle) α formed by the tangent of warp thread 1 of warp thread group A with horizontal plane 3 at the point where warp thread 1 of warp thread group A intersects with warp thread 2, which is the adjacent warp thread B. However, if the angle is too large, the weave density, particularly the weave density of the weft thread, becomes too high. Therefore, it is preferable that the angle be less than 90 degrees, and more preferably 85 degrees or less.

[0027] The weave density of the woven fabric of this embodiment may be, for example, 30 to 120 threads / inch for the warp yarns (combined warp yarns A and B), particularly 35 to 80 threads / inch, more particularly 40 to 60 threads / inch. The weave density of the weft yarns (combined weft yarns X and Y) may be, for example, 6 to 40 threads / inch, particularly 10 to 30 threads / inch, more particularly 12 to 20 threads / inch. The higher the weave density, the smoother the surface of the woven fabric will be. In addition, the higher the weave density of the weft yarns, the narrower the spacing between adjacent weft yarns, i.e., the spacing between the weft yarns of the weft yarn X group that form the knuckle portion and the adjacent weft yarn Y. As a result, the warp yarns (warp yarns of the warp yarn X group) that pass through the apex of the knuckle portion must pass under the weft yarn Y in a short distance, making the knuckle portion steeper. On the other hand, if the weaving density of the warp or weft yarns is too high, the yarns (filaments) must be woven at narrow intervals, which not only reduces productivity but also makes the knuckles too close to each other depending on the number of knuckles formed, which can make the pattern imparted to the nonwoven fabric unclear and make the yarn more susceptible to breakage.In addition, the filaments are woven under a heavy load, which can shorten the product life of the woven fabric.

[0028] As another example of this embodiment, Fig. 3 shows a weave of an embodiment where n is . The warp yarn group A is made up of warp yarns A1 to A4, and the weft yarn group X is made up of weft yarns X1 to X4. The warp yarn group A is made up of warp yarns A1, warp yarns A 2、 The warps belonging to warp group A are arranged in the order of warp A3 and warp A4, with warp B arranged on both sides of the warps belonging to warp group A (this results in a weave in which the warps belonging to warp group A and warp B are arranged alternately). The wefts belonging to weft group X are arranged in the order of weft X1, weft X2, weft X3, and weft X4, with weft Y arranged on both sides of the wefts belonging to weft group X (this results in a weave in which the wefts belonging to weft group X and weft Y are arranged alternately).

[0029] In the weave shown in FIG. 3, the relationship between the warps belonging to warp group A and weft group X will be described using warp thread A1. In the weave shown in FIG. 3, warp thread A1 passes over weft thread X1, then passes under weft threads other than weft thread X1, and then passes over X1 again. In the weave of the industrial woven fabric of the present invention, weft threads belonging to weft group X and weft thread Y are alternately arranged. Therefore, warp thread A1 passes over weft thread X1 to form a knuckle, then passes under weft thread Y adjacent to weft thread X1, and then passes under weft thread X2, weft thread Y, weft thread X3, weft thread Y, weft thread X4, and weft thread Y, and then passes over weft thread X1 again. Therefore, warp thread A1 passes over seven weft threads on the surface opposite to the surface shown in FIG. 3, forming a long crimp spanning multiple weft threads. Warp thread B repeatedly passes over warp thread X and under warp thread Y.

[0030] Although not described in detail, the relationship between the warps A2 to A4 and the wefts X2 to X4 is the same as that of the warp A1. That is, after passing over the weft X2 to form a knuckle, the warp A2 passes under the weft Y adjacent to the weft X2, and then passes under the weft X3, weft Y, weft X4, weft Y, weft X1, and weft Y, and then passes over the weft X2 again. After passing over the weft X3 to form a knuckle, the warp A3 passes under the weft Y adjacent to the weft X3, and then passes under the weft X4, weft Y, weft X1, weft Y, weft X2, and weft Y, and then passes over the weft X3 again. After passing over weft thread X4 to form a knuckle portion, warp thread A4 passes under weft thread Y adjacent to weft thread X4, then passes under weft thread X1, weft thread Y, weft thread X2, weft thread Y, weft thread X3, and weft thread Y, and then passes over weft thread X4 again.

[0031] In this example, because warp threads A are made up of four warp threads, the spacing in the weft direction of the knuckle sections formed when warp thread A1 passes over weft thread X1, for example, is longer than that of the woven fabric shown in Figure 1. By selecting the number of warp threads that make up warp threads A in this way, the spacing of the knuckle sections can be adjusted and a corresponding pattern can be formed on the nonwoven fabric.

[0032] The number of warp yarns constituting group A may be 2 to 6, particularly 2 to 4, particularly 2 to 3, and more particularly 2. If the number of warp yarns constituting group A is too large, the length of each long crimp portion becomes too long, which may reduce the strength of the woven fabric. Furthermore, as the length of each long crimp portion increases, the length that floats above the surface of the woven fabric increases. If such a surface is faced toward the machine side (e.g., the rotating roll side) during the production of nonwoven fabrics, etc., the contact time and area between the warp yarns and the moving parts of the machine (e.g., the rotating parts) increases, which may cause the warp yarns to break during use.

[0033] The shape of the knuckles can be changed by using two or more threads (e.g., monofilaments) pulled together for some or all of the warps that make up warp thread group A. For example, in Figure 1, if warp thread A1 is made up of two pulled warp threads and warp thread A2 is made up of a single warp thread, a fabric can be obtained in which knuckles of different sizes appear regularly. Alternatively, if all of the warps in warp thread group A are made up of two or more pulled warp threads, the knuckles can be made larger. Alternatively, the spacing between the knuckles can be reduced by using thinner warp and / or weft yarns.

[0034] By using warp thread B in the form of two or more parallel warp threads, the spacing in the weft direction of the knuckle portion can be increased. Alternatively, by using two or more weft yarns pulled together as the weft yarn Y, the intervals in the warp direction of the knuckle portion can be made larger.

[0035] When the industrial woven fabric of this embodiment is used as a support for nonwoven fabric production, the high, steep knuckle portions serve to impart a clear pattern to the nonwoven fabric. The industrial woven fabric of this embodiment may be used with the side opposite to the side on which the knuckle portions are formed as a conveying surface. In this case, the conveying surface is a generally smooth surface on which many long crimp portions are formed, and therefore the surface of the resulting nonwoven fabric can be relatively smooth with a lower degree of pattern clarity compared to when the side on which steep knuckle portions are formed is used as the conveying surface. In other words, when the side on which many long crimps are formed is used as the conveying surface, the difference in fiber density between the irregularities that make up the pattern on the surface of the nonwoven fabric tends to be relatively small.

[0036] The method for producing a nonwoven fabric using the woven fabric of this embodiment is not particularly limited, and may include, for example, a method for producing a short-fiber nonwoven fabric by entangling the fibers in a fiber web of short fibers using a high-pressure fluid flow (generally a high-pressure water flow) (also called a hydroentanglement method or a spunlace method), a thermal bond method (also called a thermal bonding method or a thermal adhesion method), or, in the case of a long-fiber nonwoven fabric, a nonwoven fabric produced by a spunbond method or a meltblown method.

[0037] In the hydroentanglement method, a fiber web is placed on one of the two surfaces of the woven fabric of this embodiment, on which steep protrusions (knuckle portions) are formed, and a high-pressure fluid stream (more specifically, a high-pressure water stream) is sprayed toward the fiber web while the fiber web is being transported. In the hydroentanglement method, a pattern corresponding to the knuckle portions is formed on the fiber web while the high-pressure water stream is spraying the fibers constituting the fiber web, rearranging and entangling the fibers. Therefore, the entanglement process of the fibers and the shaping process of the fiber web surface are performed simultaneously. Therefore, when the industrial woven fabric of this embodiment is used in the hydroentanglement method, a clearer pattern tends to be imparted, which is preferable.

[0038] In a method for producing a continuous fiber nonwoven fabric, such as a spunbond method or a meltblown method, the woven fabric of this embodiment can be used as a belt for depositing and transporting molten or softened fibers. In this case, a pattern corresponding to the knuckle portions is formed while the fibers in the spunbond web or meltblown web are melted or softened and deformable. In the thermal bonding method, the fabric of this embodiment can be used as a belt to support a fibrous web while it is subjected to a heat treatment, in which case the pattern corresponding to the knuckles is formed while the fibers are melted or softened and deformable.

[0039] Alternatively, since the industrial fabric of this embodiment has high, steep convex portions (knuckle portions) on one surface, by appropriately adjusting the spacing of the knuckle portions, it can be used as a conveyor belt with a small contact area with an object placed on the fabric. More specifically, when used as a dryer canvas for papermaking, the contact area with the paper being dried can be reduced, making it useful as a dryer canvas with excellent stain resistance. The method for narrowing the spacing of the knuckle portions is as described above. [Example]

[0040] Example 1 For the warp yarns constituting warp yarn group A and warp yarn B, polyester monofilaments were prepared with a rectangular cross section with rounded corners, the dimensions of the rectangle circumscribing the cross section being 0.605 mm long and 0.325 mm short. For the weft yarns constituting weft yarn group X and weft yarn Y, polyester monofilaments with a circular cross section and a diameter of 0.80 mm were prepared. Using these monofilaments, a fabric having the weave shown in Figure 1 was woven at a warp density of 47.0 ends / inch and a weft density of 17.0 ends / inch. After weaving, the fabric was heat-set at 180°C while applying a tension of 20 N / cm in the warp direction.

[0041] When the cross section of the obtained woven fabric in the warp direction was observed, it was found that at the knuckle formed by the warp yarns of warp group A passing over the weft yarns of weft group X, the warp yarns contacted 65.5% of the outer periphery of the weft yarns. Furthermore, when the cross section in the longitudinal direction was observed, at the knuckle where the warp yarns of warp group A intersected with warp yarn B, the warp yarns of warp group A formed an acute angle of 70 degrees with the horizontal plane.

[0042] Using the obtained woven fabric as a support, a nonwoven fabric was produced according to the following procedure. A fiber web was produced by mixing 80% by mass of rayon fiber (Corona (registered trademark), manufactured by Daiwabo Rayon Co., Ltd., fineness: 1.7 dtex, fiber length: 40 mm) and 20% by mass of thermal adhesive fiber (a concentric core-sheath composite fiber consisting of a core component of polypropylene and a sheath component of high-density polyethylene, product name NBF (registered trademark), manufactured by Daiwabo Co., Ltd., fineness: 1.7 dtex, fiber length: 51 mm), and using a parallel carding machine. The basis weight of this fiber web was approximately 50 g / m 2 It was.

[0043] [First water flow entanglement treatment (total entanglement treatment)] The above-mentioned fiber web was placed on a plain weave net with a warp diameter of 0.132 mm, a weft diameter of 0.132 mm, and a mesh count of 90. While the fiber web was traveling at a speed of 4 m / min, a columnar water stream at a water pressure of 2.0 MPa was sprayed onto the front surface of the fiber web, and then another columnar water stream at a water pressure of 2.0 MPa was sprayed onto the back surface of the fiber web. A nozzle with orifices with a hole diameter of 0.12 mm spaced 0.6 mm apart was used to spray the water stream. The distance between the surface of the fiber web and the orifices was 15 mm.

[0044] [Second water flow entanglement treatment (pattern formation treatment) The fiber web after the first hydroentanglement treatment was placed on the support obtained in the above example, with the back surface (the side later sprayed with the 2.0 MPa columnar water stream) facing upward and the front surface (the side previously sprayed with the 2.0 MPa columnar water stream) facing downward, i.e., toward the support. The support was oriented with the side with the knuckle portions facing upward, so that the knuckle portions were in contact with the fiber web. While the fiber web was traveling at a speed of 4 m / min, a columnar water stream at a water pressure of 2.0 MPa was sprayed once onto the front surface of the fiber web. The same nozzle as used in the first hydroentanglement treatment was used for spraying the water stream. The nonwoven fabric was then dried in a dryer adjusted to 135°C, and the sheath component of the thermally adhesive fiber contained in the fiber web was melted to thermally bond the fibers together, resulting in a patterned nonwoven fabric. A photograph of the surface of the resulting nonwoven fabric is shown in Figure 5.

[0045] The obtained nonwoven fabric had a pattern formed by the fiber density being lower in the areas corresponding to the knuckles than in other areas, and the pattern was clear and uniformly formed throughout the entire nonwoven fabric.

[0046] Example 2 A nonwoven fabric was produced under the same conditions as in Example 1, except that in the second hydroentanglement treatment, the side of the support opposite to the side on which the knuckles were formed (the side on which the long crimps were formed) was facing upward and that side was in contact with the fiber web. The surface of the obtained nonwoven fabric that had been in contact with the support had a pattern formed by the fiber density being lower in the areas corresponding to the long crimps formed on the support than in the other areas. However, on this surface, the difference in fiber density between the areas corresponding to the crimps and the other areas was smaller than the difference in fiber density between the areas corresponding to the knuckles and the other areas in Example 1, and the surface was relatively smooth and uniform.

[0047] The present disclosure includes the following aspects. (Aspect 1) An industrial fabric having warp yarns and weft yarns, The warp yarns are n (where n is a positive natural number) warp yarns (warp yarn A1, warp yarn A2, ... warp yarn An The warp threads constituting the warp thread group A and the warp thread B are arranged alternately, and the warp threads constituting the warp thread group A are arranged in a manner such that the warp thread A1, the warp thread A2, and the warp thread B are sandwiched between them. 2、 Warp A n are arranged in the order of The weft yarns are n weft yarns (weft yarn X1, weft yarn X2, ... weft yarn X n The wefts constituting the weft X group and the weft B are arranged alternately, and the wefts constituting the weft X group are arranged in the order of weft X1, weft X2, ..., weft X, with the weft Y sandwiched between them. n are arranged in the order of In the warp yarn A group, the warp yarn A m (1≦m≦n, n≧2, where m is a positive natural number) is the weft X m (1≦m≦n, n≧2 where m is a positive natural number) and warp thread A passes over m Weft X m Form a float for the weft Y and weft X m Passing under all the wefts constituting the group X except for the warp thread A m Weft Y and Weft X m It forms a sinking for all wefts constituting the weft group X other than The warp yarn B passes under the weft yarn X group and over the weft yarn Y, When a cross section in the warp direction is observed at a knuckle portion formed by passing a warp belonging to the warp yarn group A over a weft constituting the weft yarn group X, the warp yarn contacts 40% or more of the outer periphery of the weft yarn. industrial textiles. (Aspect 2) The industrial woven fabric of aspect 1, wherein at least some of the warp yarns constituting the warp yarn group A are monofilaments having a horizontally elongated cross section, and the horizontal direction of the horizontally elongated cross section is arranged parallel to the weft direction of the fabric. (Aspect 3) The industrial woven fabric according to aspect 1, wherein the monofilament has a horizontally elongated cross section, and the aspect ratio of the cross section is 1:1.1 to 1:5. (Aspect 4) The industrial woven fabric of aspect 1, wherein the warp yarns constituting the warp yarn group A and the weft yarns constituting the weft yarn group X are monofilaments made of the same material, and at least some of the warp yarns constituting the warp yarn group A have a diameter that is 50% or more and 100% or less of the diameter of the weft yarns constituting the weft yarn group X. (Aspect 5) The industrial woven fabric according to any one of aspects 1 to 4, wherein the diameter of the wefts constituting the group of wefts X is the same as or larger than the diameter of the wefts Y. (Aspect 6) The industrial woven fabric according to any one of aspects 1 to 5, wherein the number of warps constituting the warp threads A group and the number of wefts constituting the weft threads X group are 2 to 4. (Aspect 7) 7. A support for nonwoven fabric production, on which a fiber web is placed when a nonwoven fabric is produced, comprising the industrial fabric according to claim 1. (Aspect 8) The support for producing a nonwoven fabric according to embodiment 7, which is used to move a fibrous web under a high-pressure fluid stream when the fibers are entangled by the high-pressure fluid stream. (Aspect 9) A support for producing a nonwoven fabric according to embodiment 7, which is used to deposit a spunbond web or a meltblown web when producing a nonwoven fabric by a spunbond method or a meltblown method. (Aspect 10) Producing a fibrous web; subjecting the fiber web to a treatment for bonding and / or entangling the fibers constituting the fiber web while the fiber web is placed on the support for producing a nonwoven fabric of embodiment 8; A method for producing a nonwoven fabric, comprising: (Aspect 11) A method for producing a nonwoven fabric, comprising depositing filaments obtained by melt-spinning a thermoplastic resin onto the support for producing a nonwoven fabric of embodiment 7 while the thermoplastic resin is melted or softened. [Industrial Applicability]

[0048] The industrial woven fabric of the present disclosure is useful as a support for use in the production of nonwoven fabrics or as a dryer canvas for papermaking, because the high and steep knuckles enable the nonwoven fabric to have a distinct pattern or the knuckles enable the contact area between the fabric and an object placed thereon to be reduced. Alternatively, the industrial woven fabric of the present disclosure is useful as a support for producing nonwoven fabrics with a relatively smooth surface, when the surface opposite to the side on which the knuckles are formed is used as a surface on which a fibrous web is placed. [Explanation of symbols]

[0049] 1. Warp threads of warp thread group A 2 Warp thread B 3 horizontal plane

Claims

1. An industrial fabric having warp yarns and weft yarns, The warp yarns are n (where n is a positive natural number) warp yarns (warp yarns A １ , warp thread A ２ , ...warp thread A n The warp yarns constituting the warp yarn group A and the warp yarn B are arranged alternately, and the warp yarns constituting the warp yarn group A are arranged with the warp yarn B sandwiched between them. １ , warp thread A ２、 ...Warp A n are arranged in the order of The weft yarns are n weft yarns (weft yarns X １ , weft X ２ , ... weft X ｎ The wefts constituting the weft X group and the weft B are arranged alternately, and the wefts constituting the weft X group are arranged with the weft Y sandwiched between them. １ , weft X ２ , ... weft X ｎ are arranged in the order of In the warp yarn group A, the warp yarn A ｍ (1≦m≦n, n≧2, where m is a positive natural number) is the weft yarn X ｍ (1≦m≦n, n≧2, where m is a positive natural number) and passes over the ｍ Weft X ｍ A float is formed on the weft yarn Y and the weft yarn X. ｍ Passing under all the wefts constituting the weft group X other than the warp thread A ｍ Weft Y and Weft X ｍ The sinking is formed for all the weft yarns constituting the weft yarn group X other than The warp yarn B passes under the weft yarn X group and over the weft yarn Y, In a knuckle portion formed by passing a warp yarn belonging to the warp yarn group A over a weft yarn constituting the weft yarn group X, when a cross section in the warp direction is observed, the warp yarn contacts 40% or more of the outer periphery of the weft yarn. industrial textiles.

2. 2. The industrial fabric according to claim 1, wherein at least some of the warp yarns constituting the warp yarn group A are monofilaments having a horizontally elongated cross section, and the horizontal direction of the horizontally elongated cross section is arranged parallel to the weft direction of the fabric.

3. 3. The industrial fabric according to claim 2, wherein the monofilament has a horizontally elongated cross section, and the aspect ratio of the cross section is 1:1.1 to 1:

5.

4. 2. The industrial woven fabric according to claim 1, wherein the warp yarns constituting the warp yarn group A and the weft yarns constituting the weft yarn group X are monofilaments made of the same material, and at least some of the warp yarns constituting the warp yarn group A have a diameter that is in the range of 40% to 80% of the diameter of the weft yarns constituting the weft yarn group X.

5. 2. The industrial woven fabric according to claim 1, wherein the diameter of the weft yarns constituting the group of weft yarns X is the same as or larger than the diameter of the weft yarns Y.

6. 2. The industrial woven fabric according to claim 1, wherein the number of warp yarns constituting said warp yarn group A and the number of weft yarns constituting said weft yarn group X are 2 to 4.

7. A support for use in the production of nonwoven fabric, on which a fibrous web is placed when producing a nonwoven fabric, comprising the industrial fabric according to any one of claims 1 to 6.

8. 8. The support for producing nonwoven fabrics according to claim 7, which is used to move a fibrous web under a high-pressure fluid stream when the fibers are entangled by the high-pressure fluid stream.

9. 8. The support for producing nonwoven fabrics according to claim 7, which is used to deposit a spunbond web or a meltblown web when producing nonwoven fabrics by the spunbond method or the meltblown method.

10. Producing a fibrous web; The fiber web is placed on the support for producing a nonwoven fabric according to claim 7, and the fiber web is subjected to a treatment for bonding and / or entangling the fibers constituting the fiber web. A method for producing a nonwoven fabric, comprising:

11. A method for producing a nonwoven fabric, comprising depositing filaments obtained by melt-spinning a thermoplastic resin onto the support for producing a nonwoven fabric according to claim 7 while the thermoplastic resin is melted or softened.

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