Papermaking belt

Abstract

To provide a papermaking belt in which warpage of ends during use is suppressed.SOLUTION: A papermaking belt is used in a paper machine and has a first surface on which a wet paper is disposed and a second surface on the opposite side of the first surface. The papermaking belt has a reinforcement fiber substrate layer including at least one layer of woven fabric. At least one layer of the woven fabric has a double- or more layered texture. The layered texture has first yarns and second yarns disposed in parallel. The first yarns are disposed nearer to the first surface than the second yarns. The second yarns are disposed nearer to the second surface than the first yarns. The fineness of the first yarn is larger than the fineness of the second yarn.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a papermaking belt. [Background technology]

[0002] A papermaking machine that removes moisture from paper stock generally includes a wire part, a press part, and a dryer part, which are arranged in this order along the transport direction of the wet paper.

[0003] In each part of such a papermaking machine, various types of papermaking belts are used for the purpose of transporting wet paper, squeezing wet paper, etc. Examples of such papermaking belts include a wet paper transport belt (transfer belt) for transporting and transferring wet paper, and a shoe press belt used in a shoe press mechanism.

[0004] Regarding the transfer of wet paper using a wet paper transport belt in the press part, currently known paper machines are closed draw paper machines that transfer wet paper in a closed draw. In the press part of a closed draw paper machine, the wet paper is transported while being placed on a papermaking felt or a wet paper transport belt, so there is no place where the wet paper runs alone, and the occurrence of paper breaks is prevented. For this reason, closed draw paper machines are excellent in terms of suitability for high-speed operation and operational stability.

[0005] Patent document 1 proposes a papermaking belt having two layers of resin material, one layer placed on the CD support layer side and the other layer placed on the front side, with the aim of preventing warping of the edges caused by the different shrinkage characteristics of different materials and finishing processes, etc. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] WO 03 / 071030 Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, when a papermaking belt is used, it may be used together with an automatic guide device, a so-called guider, in order to prevent the papermaking belt from meandering. The guider generally detects the width direction end of the running papermaking belt and adjusts the running position of the papermaking belt. Here, if the end of the papermaking belt is warped, the guider cannot detect the exact position of the papermaking belt and cannot appropriately adjust the running position of the papermaking belt. As a result, it becomes difficult to use the papermaking belt stably.

[0008] Furthermore, papermaking belts are generally used in the presence of water, i.e., in a wet state. Therefore, the occurrence of warping at the ends of the papermaking belt must also be considered in a wet state. The papermaking belt described in Patent Document 1 is intended to simply prevent warping at the ends of the papermaking belt as a finished product, and does not take into consideration warping at the ends in a wet state.

[0009] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a papermaking belt in which curling of the ends during use is suppressed. [Means for solving the problem]

[0010] As a result of intensive research to achieve the above object, the present inventors have found that the base fabric layer constituting the papermaking belt has a relatively large effect on the warping of the end portion of the papermaking belt during use. Furthermore, they have found that the warping of the end portion of the papermaking belt can be suppressed by adopting a woven fabric having a layered structure as the base fabric layer and controlling the fineness of the yarn of the layered structure. As a result of further research, they have arrived at the present invention.

[0011] The gist of the present invention is as follows. [1] A papermaking belt used in a papermaking machine, the papermaking belt having a first surface on which a wet paper is placed and a second surface opposite to the first surface, A reinforcing fiber substrate layer including at least one layer of woven fabric, At least one layer of the woven fabric has two or more plies, The overlapping structure has first and second yarns arranged in parallel, the first thread is disposed closer to the first surface than the second thread, and the second thread is disposed closer to the second surface than the first thread; A papermaking belt, wherein the first yarns have a greater fineness than the second yarns. [2] The papermaking belt according to [1], wherein the second yarn is crimped. [3] The papermaking belt according to [1] or [2], wherein the second yarn is a multifilament twisted yarn. [4] The papermaking belt according to any one of [1] to [3], wherein the first yarns and the second yarns are arranged along a machine direction of the papermaking belt. [5] The papermaking belt according to any one of [1] to [4], which does not have a batt layer. [6] The woven fabric having the overlapping structure further includes a third yarn woven with the first yarn and the second yarn, The papermaking belt according to any one of [1] to [5], wherein the third yarn is a twisted monofilament yarn. [7] The woven fabric having the overlapping structure further includes a third yarn woven with the first yarn and the second yarn, the overlapping structure has a repeating unit that can simultaneously form a repeat in which the third yarn passes through the first surface side of K first yarns and through the second surface side of L first yarns, and a repeat in which the third yarn passes through the first surface side of M second yarns and through the second surface side of N second yarns, The papermaking belt according to any one of [1] to [6], which satisfies the relationship K / L≧N / M. [8] The woven fabric having the overlapping structure further includes a third yarn woven with the first yarn and the second yarn, The papermaking belt according to any one of [1] to [7], wherein the number of crossing points between the first yarn and the third yarn in a complete structure is greater than the number of crossing points between the second yarn and the third yarn in a complete structure. [9] The papermaking belt according to any one of [1] to [8], which is a wet paper web transfer belt.

[10] The papermaking belt according to any one of [1] to [8], which is a shoe press belt. Effect of the Invention

[0012] With the above-mentioned configuration, it is possible to provide a papermaking belt in which warping of the end portions during use is suppressed. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a cross-sectional view in the cross machine direction showing an example of a papermaking belt according to a preferred embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of a reinforcing fiber substrate of a papermaking belt according to a preferred embodiment of the present invention. [Diagram 3] FIG. 3 is a complete structure diagram of the woven fabric of the reinforcing fiber substrate of the papermaking belt according to a preferred embodiment of the present invention. [Figure 4] FIG. 4 is a complete structure diagram of a woven fabric of a reinforcing fiber substrate in a papermaking belt according to a preferred embodiment of the present invention. [Diagram 5] FIG. 4 is an enlarged cross-sectional view of a reinforcing fiber substrate of a papermaking belt according to a modified example of the present invention. [Figure 6] FIG. 4 is a complete structure diagram of a woven fabric of a reinforcing fiber substrate included in a papermaking belt according to a modified example of the present invention. [Figure 7] FIG. 4 is a complete structure diagram of a woven fabric of a reinforcing fiber substrate included in a papermaking belt according to a modified example of the present invention. [Figure 8] FIG. 8 is a cross-sectional view in the cross machine direction of a papermaking belt according to another modified example of the present invention. [Figure 9]FIG. 9 is a schematic diagram for explaining a preferred embodiment of a method for producing a papermaking belt according to the present invention. [Figure 10] FIG. 10 is a schematic diagram for explaining a preferred embodiment of a method for producing a papermaking belt according to the present invention. [Figure 11] FIG. 11 is a schematic view for explaining another preferred embodiment of the method for producing a papermaking belt according to the present invention. [Figure 12] FIG. 12 is a schematic diagram for explaining another preferred embodiment of the method for producing a papermaking belt according to the present invention. [Figure 13] FIG. 13 is a schematic diagram for explaining a method for evaluating the warpage at the end portion of the wet paper web transfer belt used in the examples. [Figure 14] FIG. 14 is a schematic diagram for explaining a method for evaluating the warpage at the end of the wet paper web transfer belt used in the examples. [Figure 15] FIG. 15 is a schematic diagram showing an example of a papermaking belt and an automatic guide device mounted on a papermaking machine. [Figure 16] FIG. 16 is a schematic diagram for explaining the relationship between the warp at the end of the papermaking belt and the detection unit (palm) of the automatic guide device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the papermaking belt according to the present invention will be described in detail with reference to the drawings.

[0015] <1. Relationship between papermaking belt and automatic guide device> First, prior to describing the papermaking belt according to the present invention, the relationship between the papermaking belt and the automatic guide device will be described. FIG. 15 is a schematic diagram showing an example of a papermaking belt and automatic guide device mounted on a papermaking machine, and FIG. 16 is a schematic diagram explaining the relationship between the warp at the end of the papermaking belt and the detection unit (palm) of the automatic guide device.

[0016] The papermaking belt 101 shown in Fig. 15 is an endless belt that runs via rolls. The automatic guide device 110 is a device that adjusts the running position of the papermaking belt 101 so that the running position of the papermaking belt 101 is not biased to the driving side or the anti-driving side of the papermaking machine during operation. The automatic guide device 110 constantly detects the position of the papermaking belt 101 and adjusts the running position of the papermaking belt 101 so that the papermaking belt 101 is in an appropriate position by changing the angle of the guide roll 102 with respect to the running direction of the papermaking belt 101.

[0017] To control the angle of the guide roll 102, a structure is generally used in which an end of an actuator 106 such as an air spring is connected to a bearing on one side of the guide roll 102, and a coil spring 107 is installed to balance the actuator 106 and the coil spring 107. By applying air pressure to the actuator 106, a bearing 108 on one side moves with a bearing 109 on the other end as a fulcrum. Then, the position of the guide roll 102 (the angle with respect to the running direction of the papermaking belt 101) is determined so that the force of the actuator 106 pressing the bearing 108 and the reaction force of the coil spring 107 are balanced.

[0018] In addition, a palm-type air pressure regulator 104 with a position detector is often used as a device that detects the position of the papermaking belt 101 and supplies the air pressure corresponding to the position to the actuator 106 of the guide roll 102. A constant air pressure (supply pressure) is supplied to the air pressure regulator 104 through a pressure reducing valve 105, while a palm 103 is brought into contact with the end of the running papermaking belt 101. Then, a change in the position of the end 1011 of the papermaking belt 101 is detected as a displacement of the contacting palm 103, and part or all of the supplied air is released to the atmosphere inside the air pressure regulator 104 due to the displacement of this palm 103, and the remaining pressure is used as the output pressure of the air pressure regulator 104. By supplying air at this output pressure to the actuator 106, the position of the guide roll 102 can be adjusted.

[0019] Here, the relationship between the palm 103 and the end 1011 of the papermaking belt 101 will be considered. As shown in FIG. 16, when the papermaking belt 101 is not warped (papermaking belt 101'), the end 1011' of the papermaking belt 101' contacts the palm 103 at an appropriate position, and the automatic guide device 110 can accurately detect the position of the papermaking belt 101'. On the other hand, when the end 1011 of the papermaking belt 101 is warped, the end 1011 is present at a distance D from the position that should be detected as a result of the end 1011 being warped, and problems such as the palm 103 being unable to contact the end 1011, the palm 103 contacting the end 1011 at a position away from the position where it should be contacted, or contacting a part of the automatic guide device 110 other than the palm 103 may occur.

[0020] In this way, when warping occurs in the papermaking belt 101, the automatic guide device 110 cannot accurately detect the position of the papermaking belt 101, and as a result, it becomes difficult to stably use the papermaking belt 101. Note that in the above explanation, the problems that can occur due to warping of the papermaking belt have been explained using as an example a palm-type automatic guide device that uses a palm as the automatic guide device, but similar problems can also occur in other mechanical automatic guide devices or optical automatic guide devices, since they detect the end of the papermaking belt and adjust the position of the papermaking belt. In view of these circumstances, the present inventors have developed a papermaking belt in which curling of the ends during use is suppressed, as described below.

[0021] <2. Wet paper transport belt (papermaking belt)> Next, a papermaking belt according to a preferred embodiment of the present invention will be described. FIG. 1 is a cross-machine cross-sectional view showing an example of a wet paper web transfer belt (papermaking belt) according to a preferred embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of a reinforcing fiber substrate of the wet paper web transfer belt shown in FIG. 1, and FIGS. 3 and 4 are complete structure diagrams of the woven fabric of the reinforcing fiber substrate of the wet paper web transfer belt shown in FIG. 1. In the drawings, the size of each member is appropriately exaggerated for ease of explanation, and the actual ratio and size of each member are not shown. Here, the cross-machine direction is also called "CMD", and the machine direction is also called "MD". In this embodiment, a wet paper web transfer belt is described as an example of a papermaking belt, but the papermaking belt of the present invention is not limited thereto.

[0022] The wet paper web transfer belt (papermaking belt) 1 shown in Fig. 1 is used for transporting and transferring a wet paper web W in the press part of a papermaking machine. The wet paper web transfer belt 1 is an endless belt. In other words, the wet paper web transfer belt 1 is a circular belt. The wet paper web transfer belt 1 is usually arranged so that its circumferential direction is along the machine direction (MD) of the papermaking system.

[0023] The wet paper web transfer belt 1 has a reinforcing fiber substrate layer 11, a first resin layer (wet paper web support side resin layer) 13 provided on one main surface (first surface 131) on the outer surface side of the reinforcing fiber substrate layer 11, and a second resin layer (roll side resin layer) 15 provided on the other main surface (second surface 151) on the inner surface side of the reinforcing fiber substrate layer 11, and is formed by laminating these layers. The first resin layer 13 is a layer that forms the outer surface (outer peripheral surface) of the ring formed by the wet paper web transfer belt 1.

[0024] The reinforcing fibrous substrate layer 11 is composed of a reinforcing fibrous substrate 111 and a resin 113. The resin 113 is present in the reinforcing fibrous substrate layer 11 as a matrix resin so as to fill gaps between the fibers in the reinforcing fibrous substrate 111. That is, a portion of the resin 113 is impregnated into the reinforcing fibrous substrate 111, while the reinforcing fibrous substrate 111 is embedded in the resin 113.

[0025] In this embodiment, the reinforcing fiber substrate 111 is a woven fabric having a double structure, and has a first warp thread 115, a second warp thread 117, and a weft thread 119. In the double structure of the reinforcing fiber substrate 111, the first warp thread 115 is arranged on the first surface 131 side (wet paper carrying side), and the second warp thread 117 is arranged on the opposite side to the first surface 131 side, that is, on the second surface 151 side (roll side). The first warp thread 115 and the second warp thread 117 are arranged in parallel. The first warp thread 115 and the second warp thread 117 are arranged in a direction perpendicular to the paper surface in Figs. 1 and 2, that is, along the machine direction (MD). On the other hand, the weft thread 119 is arranged approximately perpendicular to the first warp thread 115 and the second warp thread 117, that is, along the cross machine direction (CMD). The weft yarn 119 is interwoven with the first warp yarn 115 and the second warp yarn 117 . In addition, in order to facilitate understanding, part of the structure of the reinforcing fiber substrate 111 is shown diagrammatically in FIGS.

[0026] In this specification, the term "warp yarn" refers to a yarn arranged along the machine direction (MD) of the wet paper transfer belt (papermaking belt), i.e., the circumferential direction, and the term "weft yarn" refers to a yarn arranged along the cross machine direction (CMD) of the wet paper transfer belt (papermaking belt), i.e., a direction perpendicular to the circumferential direction and parallel to the first surface of the papermaking belt. In other words, the warp direction is set based on the machine direction of the papermaking belt and papermaking machine, i.e., the wet paper conveying direction, and the weft direction is set based on the cross machine direction of the papermaking belt and papermaking machine, i.e., the direction perpendicular to the wet paper conveying direction. In addition, the warp yarn does not have to be parallel to the machine direction (MD) of the papermaking belt, and may be arranged to have an angle of within ±10° with respect to the machine direction (MD) of the papermaking belt, for example. In addition, the weft yarn does not have to be parallel to the cross machine direction (CMD) of the papermaking belt, and may be arranged to have an angle of within ±10° with respect to the cross machine direction (CMD) of the papermaking belt, for example.

[0027] In this embodiment, the fineness of the first warp yarns 115 is greater than that of the second warp yarns 117. This suppresses warping of the ends, that is, the ends in the width direction (CMD) of the wet paper web transfer belt 1 during use.

[0028] More specifically, the inventors have found that the warping of the ends of a wet web transfer belt during use includes not only the initial warping present in the finished product immediately after manufacture, but also warping caused by wetting with water or the like during use and by mechanical action in a papermaking machine. Furthermore, the inventors have focused on the possibility that warping caused by swelling of the wet web transfer belt with water or the like during use may have the greatest impact on the warping of the ends of a papermaking belt during use.

[0029] The inventors have found that the warping of the end of the wet paper web transfer belt can be controlled by adjusting the fineness of two parallel yarns in the woven fabric, in which the reinforcing fiber substrate has a woven fabric having a layered structure. Specifically, the fineness of the first yarn on the first surface side on which the wet paper web is placed is made larger than the fineness of the second yarn on the opposite second surface side, so that the density of the wet paper web support side of the woven fabric increases, and as a result, the rigidity of the wet paper web support side increases. This prevents the end of the reinforcing fiber substrate provided with the woven fabric from warping toward the wet paper web support side. As a result of the above, warping of the end of the wet paper web transfer belt and warping toward the wet paper web support side during use are prevented. In this embodiment, the first warp yarn 115 is used as the first yarn, and the second warp yarn 117 is used as the second yarn.

[0030] As described above, the fineness of the first warp thread 115 may be larger than that of the second warp thread 117, and for example, the fineness of the first warp thread 115 is larger than that of the second warp thread 117 by 50 dtex or more, preferably 100 dtex or more, and more preferably 200 dtex or more. This makes it possible to more effectively suppress the warping of the end portion of the wet paper web transfer belt 1 during use. In addition, the fineness of the first warp thread 115 can be larger than that of the second warp thread 117 by, for example, 3000 dtex or less, preferably 2500 dtex or less, and more preferably 1000 dtex or less. This makes it possible to suppress the end portion of the wet paper web transfer belt 1 from warping toward the roll side due to the fineness of the first warp thread 115 being excessively larger than that of the second warp thread 117.

[0031] The fineness of the first warp threads 115 may be larger than that of the second warp threads 117, and is, for example, 500 dtex to 8000 dtex, preferably 1000 dtex to 6000 dtex, and more preferably 2000 dtex to 4000 dtex. This ensures sufficient rigidity of the reinforcing fiber substrate 111, and more effectively suppresses warping of the ends of the wet paper web carrying side and the roll side of the wet paper web transfer belt 1.

[0032] The fineness of the second warp threads 117 may be smaller than that of the first warp threads 115, and may be, for example, 500 dtex to 8000 dtex, preferably 1000 dtex to 6000 dtex, and more preferably 2000 dtex to 4000 dtex. This makes it possible to more effectively suppress warping of the end portions of the wet web transfer belt 1 while ensuring sufficient strength of the reinforcing fiber substrate 111 and thus the strength of the wet web transfer belt 1.

[0033] The fineness of the weft yarn 119 is not particularly limited, but is, for example, 500 dtex to 6000 dtex, preferably 800 dtex to 3000 dtex, and more preferably 1000 dtex to 2000 dtex. This ensures sufficient strength of the reinforcing fiber substrate 111 and thus the strength of the wet paper web transfer belt 1, while sufficiently suppressing waviness caused by weaving of the reinforcing fiber substrate 111.

[0034] Furthermore, the materials constituting the first warp thread 115, the second warp thread 117 and the weft thread 119 are not particularly limited, and the following can be used alone or in combination: polyester (polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), aliphatic polyamide (polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610, polyamide 612, etc.), aromatic polyamide (aramid), polyvinylidene fluoride, polypropylene, polyether ether ketone, polytetrafluoroethylene, polyethylene, wool, cotton, metal, etc. Any two or more of the first warp thread 115, the second warp thread 117, and the weft thread 119 may be made of the same material, or may be made of different materials.

[0035] Among the above, the first warp yarns 115 preferably contain one or more selected from the group consisting of polyester, aliphatic polyamide and aromatic polyamide (aramid), and more preferably contain one or more selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610 and polyamide 612. This allows the wet paper web transfer belt 1 to maintain both strength and dimensional stability during use.

[0036] Among the above, the second warp yarn 117 preferably contains one or more selected from the group consisting of polyester, aliphatic polyamide and aromatic polyamide (aramid), more preferably contains one or more selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610 and polyamide 612. This allows the strength and dimensional stability of the wet paper web transfer belt 1 to be maintained during use. In addition, since polyester, especially polyethylene terephthalate, is a material with relatively low water absorption, when polyester is used for the second warp yarn 117, swelling of the second warp yarn 117 due to water during use of the wet paper web transfer belt 1 is suppressed, and as a result, warping of the end of the wet paper web transfer belt 1 can be more effectively suppressed.

[0037] Among the above, the weft yarn 119 preferably contains one or more selected from the group consisting of polyester, aliphatic polyamide and aromatic polyamide (aramid), and more preferably contains one or more selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610 and polyamide 612. This allows the wet paper web transfer belt 1 to maintain both strength and dimensional stability during use.

[0038] Moreover, the first warp yarn 115, the second warp yarn 117, and the weft yarn 119 may be any type of yarn, and may be spun yarn (spun yarn) or filament yarn. However, from the viewpoint of ensuring the strength of the reinforcing fiber substrate 111, and in turn the wet paper web transfer belt 1, it is preferable that the first warp yarn 115, the second warp yarn 117, and the weft yarn 119 are all filament yarns. The first warp yarn 115, the second warp yarn 117, and the weft yarn 119 may be different types of yarns or the same type of yarns.

[0039] Examples of the filament yarn include twisted multifilament or monofilament yarn, paralleled multifilament and / or monofilament yarn, and single monofilament yarn.

[0040] Here, in this specification, the term "multifilament" refers to a filament composed of two or more single yarns. Usually, the single yarns constituting the multifilament have a fineness that cannot be used alone as a yarn of a reinforcing fiber substrate. Specifically, the fineness of the single yarns constituting the multifilament is, for example, less than 100 dtex, preferably 5 dtex to 50 dtex. Also, a monofilament is a filament consisting of one piece. Usually, the single yarns constituting the monofilament have a fineness that can be used alone as a yarn of a reinforcing fiber substrate. The fineness of the monofilament is, for example, 100 dtex to 6000 dtex, preferably 200 dtex to 2500 dtex.

[0041] The term "multifilament twisted yarn" refers to a twisted yarn using a multifilament as a raw yarn, and the term "multifilament drawn yarn" refers to a yarn obtained by drawing and aligning a plurality of single yarns that constitute the multifilament as a raw yarn.

[0042] When used as a multifilament or monofilament drawn yarn, the raw yarns are drawn so that the resulting filament yarn has a desired fineness, for example, to obtain the drawn yarn. In this case, the fineness of the single yarn constituting the multifilament raw yarn is preferably 5 dtex or more and less than 100 dtex, more preferably 5 dtex or more and 50 dtex or less. The fineness of the monofilament raw yarn is preferably 100 dtex or more and 1000 dtex or less, more preferably 100 dtex or more and 500 dtex or less.

[0043] When using a twisted yarn of multifilament or monofilament, a twisted yarn of a single twist or a single twist can be used. In the case of twisting, a plurality of raw yarns are aligned so as to have a thickness of, for example, 200 dtex or more and 2500 dtex or less, preferably 300 dtex or more and 2000 dtex or less, and the aligned raw yarns are twisted. Then, a plurality of, for example, 2 to 10, twisted raw yarns are aligned so as to have a desired fineness, and further twisted to obtain a twisted yarn of multifilament or monofilament. In this case, the number of twists in the first twist is not particularly limited, but is, for example, 0.05 times / cm or more and 20.0 times / cm or less, preferably 0.1 times / cm or more and 10.0 times / cm or less. The number of twists in the second twist is not particularly limited, but is, for example, 0.05 times / cm or more and 20.0 times / cm or less, preferably 0.1 times / cm or more and 10.0 times / cm or less.

[0044] In the case of single-twist, multiple raw yarns are aligned to the desired fineness, and the aligned raw yarns are twisted to obtain a single-twist multifilament or monofilament twisted yarn. In this case, the number of twists is not particularly limited, but is, for example, 0.05 turns / cm or more and 20.0 turns / cm or less, preferably 0.1 turns / cm or more and 10.0 turns / cm or less.

[0045] In the case of using twisted yarn, the fineness of the single yarn constituting the raw yarn of the multifilament is preferably 5 dtex or more and less than 100 dtex, more preferably 5 dtex or more and 50 dtex or less, and the fineness of the raw yarn of the monofilament is preferably 200 dtex or more and 1500 dtex or less, more preferably 300 dtex or more and 1000 dtex or less.

[0046] In addition, the first warp thread 115, the second warp thread 117, and the weft thread 119 may be appropriately processed. Examples of such processing include stretching and shrinking.

[0047] Of the above, the first warp yarn 115 preferably includes a monofilament, more preferably includes a twisted monofilament yarn, and further preferably includes a twisted monofilament yarn.

[0048] Among the above, the second warp yarn 117 preferably contains a multifilament, more preferably a twisted multifilament yarn, and even more preferably a twisted multifilament yarn. When a multifilament is used as the second warp yarn 117, the impregnation speed of the resin material from the second surface 151 side can be reduced during the manufacture of the wet paper web transfer belt 1, and a second resin layer 15 of sufficient thickness can be formed without forming a batt layer. As a result, it is possible to omit the batt layer, and warping of the end portion of the wet paper web transfer belt 1 is further suppressed.

[0049] Furthermore, the second warp yarns 117 are preferably subjected to a crimping process, so that the impregnation speed of the resin material from the second surface 151 side can be reduced during the manufacture of the wet paper web transfer belt 1, and the second resin layer 15 can be formed with a sufficient thickness.

[0050] Among the above, the weft yarn 119 preferably includes a monofilament, more preferably includes a twisted monofilament, and further preferably includes a twisted monofilament, whereby warping of the end portion of the wet paper web transfer belt 1 during use can be more effectively suppressed.

[0051] As described above, the reinforcing fiber base 111 is a woven fabric having a double structure with the first warp yarns 115 and the second warp yarns 117 as warps and the weft yarns 119 as wefts. The structure of the reinforcing fiber base 111 will be described below with reference to Figs. 2 to 4.

[0052] 2 and as described above, in the double weave of the reinforcing fiber substrate 111, the first warp thread 115 is disposed on the first surface 131 side (wet paper carrying side), and the second warp thread 117 is disposed on the opposite side to the first surface side, i.e., on the second surface 151 side (roll side). Then, the weft thread 119 is woven with the first warp thread 115 and the second warp thread 117 to form the woven structure of the reinforcing fiber substrate 111.

[0053] Specifically, the relationship between the first warp thread 115 and the weft thread 119 is such that the weft thread 119 passes over the first surface 131 side of one first warp thread 115 (1, 5, 9, 13, 17 in FIG. 2), and then passes over the second surface 151 side of three first warp threads 115 (2-4, 6-8, 10-12, 14-16, 18-20 in FIG. 2). Also, the relationship between the second warp thread 117 and the weft thread 119 is such that the weft thread 119 passes over the first surface 131 side of seven second warp threads 117 (4-10, 12-18 in FIG. 2), and then passes over the second surface 151 side of one second warp thread 117 (3, 11, 19 in FIG. 2). The overlapping structure of the reinforcing fiber substrate 111 has a repeating unit R so that the repeating relationship between the first warp thread 115 and the weft thread 119 and the repeating relationship between the second warp thread 117 and the weft thread 119 can be formed simultaneously.

[0054] In the following description, a woven fabric having a repeat unit capable of simultaneously forming a repeat in which a weft passes through the first surface side of K first warps and then passes through the second surface side 151 of L first warps 115, and a repeat in which a weft passes through the first surface side of M second warps and then passes through the second surface side of N second warps, is also referred to as "L / KN / M." Therefore, the woven fabric shown in FIG. 2 can be expressed as a "3 / 1 1 / 7" double weave.

[0055] It is preferable that the above-mentioned K, L, M, and N satisfy the relationship K / L≧N / M. This increases the density of the wet paper web-supporting (first surface 131) side of the woven fabric of the reinforcing fiber substrate 111, resulting in increased rigidity on the wet paper web-supporting side. Therefore, the reinforcing fiber substrate 111 is more effectively prevented from warping at its ends toward the wet paper web-supporting side, and warping of the ends of the wet paper web transfer belt 1 toward the wet paper web-supporting side during use is more effectively prevented. It is even more preferable that K, L, M, and N satisfy the relationship K / L>N / M.

[0056] FIG. 3 is a complete structure diagram showing the relationship between the first warp yarn 115 and the weft yarn 119 of the reinforcing fiber substrate 111. This complete structure diagram allows observation of which of the first warp yarn 115 and the weft yarn 119 is exposed to the first surface 131 side when the reinforcing fiber substrate 111 is viewed in plan from the first surface 131 side. In FIG. 3, the first warp yarn 115 is exposed to the first surface 131 side in the black portion, and the weft yarn 119 is exposed to the first surface 131 side in the white portion. In other words, the weft yarn 119 crosses the first warp yarn 115 and turns back in the white portion to form a crossing point (knuckle portion). In this embodiment, the number of crossing points between the weft yarn 119 and the first warp yarn 115 in the complete structure is 16.

[0057] FIG. 4 is a complete structure diagram showing the relationship between the second warp yarn 117 and the weft yarn 119 of the reinforcing fiber substrate 111. This complete structure diagram allows observation of which of the second warp yarn 117 and the weft yarn 119 is exposed to the second surface 151 side when the reinforcing fiber substrate 111 is viewed in plan from the second surface 151 side. In FIG. 4, the second warp yarn 117 is exposed to the second surface 151 side in the black portion, and the weft yarn 119 is exposed to the second surface 151 side in the white portion. In other words, the weft yarn 119 crosses the second warp yarn 117 and turns back in the white portion to form a crossing point (knuckle portion). In this embodiment, the number of crossing points between the weft yarn 119 and the second warp yarn 117 in the complete structure is eight.

[0058] Thus, in this embodiment, the number of intersections between the weft yarn 119 and the first warp yarn 115 in the complete design is greater than the number of intersections between the weft yarn 119 and the second warp yarn 117 in the complete design. This increases the density of the wet paper web-supporting (first surface 131) side of the woven fabric of the reinforcing fiber substrate 111, resulting in increased rigidity of the wet paper web-supporting side. Therefore, the reinforcing fiber substrate 111 is more effectively prevented from warping its ends toward the wet paper web-supporting side, and warping of the ends of the wet paper web transfer belt 1 toward the wet paper web-supporting side during use is more effectively prevented.

[0059] In addition to the specific woven fabric as described above, the reinforcing fiber substrate 111 may contain other woven fabrics and / or other fiber materials such as a lattice material in which warp and weft threads are overlapped without weaving. The reinforcing fiber substrate 111 may also contain threads arranged in a spiral shape along the circumferential direction. Furthermore, the fineness of the fibers constituting the reinforcing fiber substrate 111 may vary depending on the location where the fibers are used.

[0060] The material of the resin 113 contained in the reinforcing fiber substrate layer 11 is not particularly limited, and thermosetting resins such as urethane resin, epoxy resin, acrylic resin, etc., or thermoplastic resins such as polyamide resin, polyarylate resin, polyester resin, etc. can be used alone or in combination of two or more kinds, and preferably urethane resin can be used.

[0061] The urethane resin used for the resin 113 is not particularly limited, but may be, for example, a urethane resin obtained by curing a urethane prepolymer having an isocyanate group at the end, obtained by reacting a polyisocyanate compound with a polyol, together with a curing agent having an active hydrogen group. In addition, anionic, nonionic, or cationic self-emulsifying or forced emulsifying water-based urethane resins may be used.

[0062] As described above, the urethane resin includes, for example, a urethane resin obtained by curing a urethane prepolymer having an isocyanate group at the end, which is obtained by reacting a water-based urethane resin and / or a polyisocyanate compound with a polyol, together with a curing agent having an active hydrogen group. Note that any urethane resin is formed using a polyisocyanate compound, a polyol, and, if necessary, a curing agent. Therefore, the polyisocyanate compound, polyol, and curing agent that constitute the urethane resin will be described below.

[0063] Examples of the polyisocyanate compound include aromatic polyisocyanate compounds and aliphatic polyisocyanate compounds, and one of these can be used alone or two or more can be used in combination. Examples of the aromatic polyisocyanate compound include 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4'-methylenebis(phenylisocyanate) (MDI), p-phenylene diisocyanate (PPDI), dimethylbiphenylene diisocyanate (TODI), naphthalene-1,5-diisocyanate (NDI), 4,4-dibenzyl diisocyanate (DBDI), xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), polymethylene polyphenyl polyisocyanate (polymeric MDI), etc.

[0064] The aliphatic polyisocyanate compound is not particularly limited, but examples thereof include chain aliphatic polyisocyanates such as 1,6-hexamethylene diisocyanate (HDI) and 1,5-pentamethylene diisocyanate, and alicyclic polyisocyanates such as 1-isocyanate-3-isocyanatemethyl-3,5,5-trimethylcyclohexane (IPDI), dicyclohexylmethane-4,4'-diisocyanate (H12MDI), 1,3-cyclohexyl diisocyanate, 1,4-cyclohexyl diisocyanate (CHDI), and 1,4-bis-(isocyanatemethyl)cyclohexane (H6XDI). Among these, one type may be used alone, or two or more types may be used in combination.

[0065] Among the above, the polyisocyanate compound preferably contains one or more selected from the group consisting of 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4'-methylenebis(phenylisocyanate) (MDI), 1-isocyanate-3-isocyanatemethyl-3,5,5-trimethylcyclohexane (IPDI) and dicyclohexylmethane-4,4'-diisocyanate (H12MDI). This can improve the crack resistance, abrasion resistance and wet paper transport property (balance between adhesion and peelability between wet paper W and wet paper transport belt 1) of the wet paper transport belt 1.

[0066] The polyol compound is not particularly limited, and examples thereof include long-chain polyol compounds, for example, polyester polyols such as polycaprolactone polyol and polyethylene adipate, polyether polyols such as polyethylene glycol, polyoxypropylene glycol, polyhexamethylene ether glycol and polytetramethylene ether glycol (PTMG), polycarbonate polyols such as polycarbonate diol, polyether carbonate diol, polybutadiene polyol, perfluoropolyether polyol, and silicone polyols such as silicone diol, and these can be used alone or in combination of two or more.

[0067] The polycarbonate polyol is not particularly limited, but may be, for example, a polycarbonate polyol synthesized from a polycarbonate polyol raw material polyol and a polycarbonate source. The polycarbonate polyol raw material polyol is not particularly limited, but may be, for example, a linear or branched alkylene glycol having a carbon number of 2 to 20, or a hydroxyl-containing cyclic hydrocarbon having a carbon number of 2 to 20, and may be used alone or in combination of two or more. The linear alkylene glycol may be, for example, ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, undecanediol, dodecanediol, etc. Examples of the branched alkylene glycol include 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, etc. Examples of the hydroxyl group-containing cyclic hydrocarbon include hydroxyl group-containing alicyclic alkanes such as 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, etc.

[0068] Among the above, the polyol compound preferably contains at least one selected from the group consisting of polyether polyol, polycarbonate polyol and polyether carbonate diol, more preferably at least one selected from the group consisting of polytetramethylene ether glycol (PTMG) and polycarbonate polyol synthesized from hexanediol and a polycarbonate source. This can improve the crack resistance, abrasion resistance and wet paper transport property (balance of adhesion and peelability between the wet paper W and the wet paper transport belt 1) of the wet paper transport belt 1.

[0069] The curing agent having an active hydrogen group is not particularly limited, and one or more compounds selected from the group consisting of polyol compounds and polyamines can be used.

[0070] As the polyol compound that can be contained in the curing agent, in addition to the above-mentioned long-chain polyol compounds, various aliphatic polyol compounds and various alicyclic or aromatic polyol compounds can be used.

[0071] The aliphatic polyol compound is not particularly limited, and examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1, Examples of suitable alkylene glycol compounds include 12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, 1,20-icosanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, and 2-methyl-1,8-octanediol; as well as glycerin, ditrimethylolpropane, trimethylolpropane (TMP), pentaerythritol, and dihydroxymethylpropionic acid (DHPA).

[0072] The alicyclic polyol compound is not particularly limited, and examples thereof include 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, and the like. The aromatic polyol compound is not particularly limited, and examples thereof include hydroquinone bis-β-hydroxyethyl ether (HQEE), hydroxyphenyl ether resorcinol (HER), 1,3-bis(2-hydroxyethoxybenzene), 1,4-bis(2-hydroxyethoxybenzene), bisphenol A, alkylene oxide adducts of bisphenol A, bisphenol S, and alkylene oxide adducts of bisphenol S.

[0073] The polyamine is not particularly limited, and examples thereof include hydrazine, ethylenediamine, 4,4'-methylene-bis-(2-chloroaniline) (MOCA), dimethylthiotoluenediamine (DMTDA), diethyltoluenediamine (DETDA), trimethylene glycol di(p-aminobenzoate) (TMAB), 4,4'-methylene-bis-(3-chloro-2,6-diethylaniline) (MCDEA), 4,4'-methylene-bis-(2,6-diethylaniline) (MDEA), triisopropanolamine (TIPA), p-bis(aminocyclohexyl)methane (PACM), naphthalene-1,5-diamine, xylylenediamine, phenylenediamine, toluene-2,4-diamine, t-butyltoluenediamine, 1,2-bis(2-aminophenylthioethane), and 2-(2-aminoethylamino)ethanol.

[0074] Among the above, the curing agent preferably contains one or more selected from the group consisting of aliphatic polyol compounds and polyamines, more preferably one or more selected from the group consisting of ethylene glycol, butanediol, trimethylolpropane (TMP), dimethylthiotoluenediamine (DMTDA), and diethyltoluenediamine (DETDA). This can improve the crack resistance, abrasion resistance, and wet paper transportability (balance between adhesion and peelability between the wet paper W and the wet paper transport belt 1) of the wet paper web transfer belt 1.

[0075] Furthermore, the resin 113 of the reinforcing fiber substrate layer 11 may be crosslinked by a crosslinking agent. Examples of the crosslinking agent include various crosslinking agents such as carbodiimide-based, melamine-based, epoxy-based, and isocyanate-based crosslinking agents, which may be used alone or in combination of two or more. Furthermore, the crosslinking agent may be a crosslinking agent composition containing a solvent, a dispersant, a surfactant, and the like, or may be a liquid (for example, a solution, a dispersion, or an emulsion). Furthermore, when the crosslinking agent is in the form of a solution, the crosslinking agent may be an aqueous solution.

[0076] The above-mentioned crosslinking agent may be used by mixing with materials for constituting the urethane resin, such as a urethane prepolymer and a curing agent, or may be used by mixing with a dispersion of a water-based urethane resin.

[0077] Resin 113 may also contain one or a combination of two or more of inorganic fillers such as titanium oxide, kaolin, clay, talc, diatomaceous earth, calcium carbonate, calcium silicate, magnesium silicate, silica, and mica.

[0078] The composition and type of the resin 113 in the reinforcing fibrous substrate layer 11 may be different for each portion in the reinforcing fibrous substrate layer 11 or may be the same.

[0079] The first resin layer 13 is a layer provided on one main surface of the reinforcing fiber substrate layer 11 and is mainly composed of resin. The first resin layer 13 constitutes a first surface 131 on which the wet paper web W is placed on the main surface opposite to the main surface bonded to the reinforcing fiber substrate layer 11. That is, the wet paper web transfer belt 1 can carry the wet paper web W on the first surface 131 of the first resin layer 13 and transport the wet paper web W. In the illustrated embodiment, the wet paper web W is directly placed on the first surface 131. However, the wet paper web W may be indirectly placed on the first surface 131. For example, depending on the usage mode, another device, such as felt, may be placed between the first surface 131 and the wet paper web W, and the wet paper web W may be placed on the first surface 131 via the other device.

[0080] The material of the resin constituting the first resin layer 13 is not particularly limited, and for example, the various resins that can be used for the resin 113 of the reinforcing fibrous substrate layer 11 described above can be used alone or in combination of two or more. The resin constituting the first resin layer 13 may be the same as or different from the resin 113 of the reinforcing fibrous substrate layer 11 in terms of type and composition.

[0081] In addition, the resin constituting the first resin layer 13 may contain one or more inorganic fillers in combination, such as titanium oxide, kaolin, clay, talc, diatomaceous earth, calcium carbonate, calcium silicate, magnesium silicate, silica, and mica. By including such an inorganic filler in the resin constituting the first resin layer 13, the surface state of the first surface 131 of the first resin layer 13, such as the uneven state, surface roughness, and hydrophilicity, can be more easily controlled, and the function of transporting the wet paper web W in a state where it is attached (wet paper web adhesion) and the function of smoothly releasing the wet paper web W when transferring the wet paper web W to the subsequent stage (wet paper web releasability) required for the wet paper web transfer belt 1 can be more reliably achieved.

[0082] On the other hand, since the inorganic filler is less likely to absorb moisture than other parts constituting the wet web transfer belt 1 during use, it is likely to be a cause of warping at the ends of the wet web transfer belt 1. However, in this embodiment, since the wet web transfer belt 1 includes the reinforcing fiber base material 111 described above, warping at the ends of the wet web transfer belt 1 is sufficiently suppressed even when an inorganic filler is used.

[0083] Moreover, the first resin layer 13 preferably has a property of not allowing water to pass therethrough, that is, the first resin layer 13 is preferably water-impermeable.

[0084] The second resin layer (roll surface side resin layer) 15 is a layer provided on one main surface of the reinforcing fiber substrate layer 11 and is mainly composed of resin. The second resin layer 15 constitutes a second surface 151 for contacting a roll, which will be described later, on the main surface opposite to the main surface bonded to the reinforcing fiber substrate layer 11. When the wet paper web transfer belt 1 is in use, the second surface 151 comes into contact with the roll, so that the wet paper web transfer belt 1 can obtain power for transferring the wet paper web from the roll. In addition, the second surface 151 can be formed with unevenness by arranging the second warp yarns 117 on the second surface 151, which can prevent the so-called hydroplaning phenomenon in which the wet paper web transfer belt 1 and the roll slip.

[0085] The resin constituting the second resin layer 15 may be one or a combination of two or more of the resin materials that can be used for the first resin layer 13 as described above. The resin constituting the second resin layer 15 may be the same as or different from the resin constituting the first resin layer 13 or the resin 113 constituting the reinforcing fiber substrate layer 11 in terms of type and composition.

[0086] Similarly to the first resin layer 13, the second resin layer 15 may contain one or more types of inorganic fillers. The composition and type of the resin material and inorganic filler in the second resin layer 15 may be different for each portion in the second resin layer 15 or may be the same.

[0087] The dimensions of the wet paper web transfer belt 1 as described above are not particularly limited, and can be appropriately set according to the application. For example, the width of the wet paper web transfer belt 1 is not particularly limited, but can be set to 700 to 13,500 mm, preferably 2,500 to 12,500 mm. For example, the length (circumferential length) of the wet paper web transfer belt 1 is not particularly limited, but may be 4 to 35 m, and preferably 10 to 30 m.

[0088] The thickness of the wet paper web transfer belt 1 is not particularly limited, but may be, for example, 1.5 to 7.0 mm, and preferably 2.0 to 6.0 mm. Furthermore, the thickness of each portion of the wet paper web transfer belt 1 may be different or the same.

[0089] The above-described wet web transfer belt 1 can be manufactured, for example, by a manufacturing method for a wet web transfer belt according to this embodiment, which will be described later.

[0090] As described above, the wet paper web transfer belt 1 according to this embodiment includes a woven fabric in which the reinforcing fiber substrate 111 has a double weave, and the fineness of the first warp yarn 115 in the woven fabric is greater than the fineness of the second warp yarn 117. This suppresses warping of the ends, i.e., the ends in the width direction (CMD), of the wet paper web transfer belt 1 during use. As a result, the automatic guide device can detect the position of the wet paper web transfer belt 1 with higher accuracy and more appropriately control the position of the wet paper web transfer belt 1. Such a wet paper web transfer belt 1 can be used stably.

[0091] <2. Modifications> Next, some modified examples of the papermaking belt according to the above-mentioned embodiment will be described. Below, differences from the above-mentioned embodiment will be mainly described, and similar points will not be described. In addition, the modified examples described below and the features of the above-mentioned embodiment may be applied independently, or two or more of them may be applied in combination as long as it is technically permissible.

[0092] (2.1. First Modification) FIG. 5 is an enlarged cross-sectional view of a reinforcing fiber substrate of a wet paper web transfer belt (papermaking belt) according to a first modified example, and FIGS. 6 and 7 are complete structure diagrams of the woven fabric of the reinforcing fiber substrate of the wet paper web transfer belt of FIG. 5.

[0093] The wet paper web transfer belt 1A according to the first modification is different from the above-mentioned embodiment in that it has a reinforcing fibrous substrate 111A as shown in Figures 5 to 7 instead of the reinforcing fibrous substrate 111 in the above-mentioned embodiment, but is otherwise basically similar. The reinforcing fibrous substrate 111A will be described below.

[0094] The reinforcing fiber substrate 111A is a woven fabric having a double structure, and has a first warp thread 115A, a second warp thread 117A, and a weft thread 119A. In the double structure of the reinforcing fiber substrate 111A, the first warp thread 115A is arranged on the first surface side (wet paper carrying side, not shown), and the second warp thread 117A is arranged on the opposite side to the first surface side, that is, on the second surface side (roll side, not shown). The first warp thread 115A and the second warp thread 117A are arranged in parallel. The first warp thread 115A and the second warp thread 117A are arranged along the machine direction (MD). On the other hand, the weft thread 119A is arranged substantially perpendicular to the first warp thread 115A and the second warp thread 117A, that is, along the cross machine direction (CMD). The weft yarn 119A is interwoven with the first warp yarn 115A and the second warp yarn 117A.

[0095] Specifically, the relationship between the first warp thread 115A and the weft thread 119A is such that the weft thread 119A passes through the first surface side of one first warp thread 115A (1, 5, 9, 13, 17 in FIG. 5), and then passes through the second surface side of three first warp threads 115A (2-4, 6-8, 10-12, 14-16 in FIG. 5). The relationship between the second warp thread 117A and the weft thread 119A is such that the weft thread 119A passes through the first surface side of three second warp threads 117A (4-6, 8-10, 12-14, 16-18 in FIG. 5), and then passes through the second surface side of one first warp thread 115A (3, 7, 11, 15 in FIG. 5). The overlapping structure of the reinforcing fiber base 111A has a repeating unit R' so that the repeating relationship between the first warp thread 115A and the weft thread 119A and the repeating relationship between the second warp thread 117A and the weft thread 119A can be simultaneously formed. The weave structure of the reinforcing fiber base 111 shown in Fig. 5 described above can be expressed as a "3 / 1 1 / 3" double structure.

[0096] FIG. 6 is a complete structure diagram showing the relationship between the first warp yarn 115A and the weft yarn 119A of the reinforcing fiber substrate 111A. This complete structure diagram allows observation of which of the first warp yarn 115A and the weft yarn 119A is exposed to the first surface side when the reinforcing fiber substrate 111A is viewed in plan from the first surface side. In FIG. 6, the first warp yarn 115A is exposed to the first surface side in the black portion, and the weft yarn 119A is exposed to the first surface side in the white portion. In other words, the weft yarn 119A crosses the first warp yarn 115A and turns back in the white portion to form a crossing point (knuckle portion). In this modified example, the number of crossing points between the weft yarn 119A and the first warp yarn 115A in the complete structure is four.

[0097] FIG. 7 is a complete structure diagram showing the relationship between the second warp yarn 117A and the weft yarn 119A of the reinforcing fiber substrate 111A. This complete structure diagram allows observation of which of the second warp yarn 117A and the weft yarn 119A is exposed to the second surface side when the reinforcing fiber substrate 111A is viewed in plan from the second surface side. In FIG. 7, the second warp yarn 117A is exposed to the second surface side in the black portion, and the weft yarn 119A is exposed to the second surface side in the white portion. In other words, the weft yarn 119A crosses the second warp yarn and turns back in the white portion to form a crossing point (knuckle portion). In this modified example, the number of crossing points between the weft yarn 119A and the second warp yarn 117A in the complete structure is four.

[0098] In the wet paper web transfer belt 1A as described above, the fineness of the first warp threads 115A is also greater than the fineness of the second warp threads 117A, thereby achieving the same effects as those of the above-mentioned embodiment.

[0099] (2.2. Second Modification) 8 is a cross-machine cross-sectional view of a wet paper web transfer belt (papermaking belt) according to a second modified example. The wet paper web transfer belt 1B according to the second modified example differs from the above-mentioned embodiment in that it has a first resin layer 13B in which batt fibers are impregnated with a resin material and a second resin layer 15B in which batt fibers are impregnated with a resin material, instead of the first resin layer 13 and the second resin layer 15 in the above-mentioned embodiment.

[0100] The first resin layer 13B is obtained by impregnating a batt fiber layer formed on the reinforcing fiber substrate layer 11B with a resin material. Therefore, the first resin layer 13B includes batt fibers and a resin as a matrix. The resin material of the first resin layer 13B can be the same as the resin material of the first resin layer 13 in the above-mentioned embodiment. In addition, the material of the batt fibers can be one type or a combination of two or more types of materials that can be used for the reinforcing fiber substrate 111 in the above-mentioned embodiment.

[0101] The second resin layer 15B is obtained by impregnating the batt fiber layer formed on the reinforcing fiber substrate layer 11B with a resin material. Therefore, the second resin layer 15B includes batt fibers and a resin as a matrix. The resin material of the second resin layer 15B may be the same as the resin material of the first resin layer 13 in the above-mentioned embodiment. In addition, the material of the batt fibers may be one type or a combination of two or more types of materials that can be used for the reinforcing fiber substrate 111 in the above-mentioned embodiment.

[0102] In addition, batt fiber layers are disposed on both sides of the reinforcing fibrous substrate layer 11B following the formation of the first resin layer 13B and the second resin layer B as described above. Such batt fiber layers are formed by disposing batt fibers on both sides of the reinforcing fibrous substrate layer 11B and entangling the batt fibers with the reinforcing fibrous substrate layer 11B by needling. Therefore, although not shown, batt fibers are entangled with the reinforcing fibrous substrate 111B of the reinforcing fibrous substrate layer 11B. The other configurations of the reinforcing fibrous substrate layer 11B are similar to those of the reinforcing fibrous substrate 111 of the above-described embodiment.

[0103] As described above, in this modified example, the first resin layer 13B and the second resin layer 15B contain not only resin but also batt fibers. When the first resin layer 13B and the second resin layer 15B contain batt fibers in this way, moderate unevenness is generated on the first surface 131B of the first resin layer 13B and the second surface 151B of the second resin layer 15B. As a result, it becomes easier to control the adhesion and peelability of the wet paper web W on the first surface 131B. In addition, sufficient friction can be obtained against the contacting roll on the second surface 151B, and the power from the roll can be transmitted to the wet paper web transfer belt 1 more efficiently. In addition, the second surface 151B can also form unevenness by arranging batt fibers on the second surface 151B, which can prevent the so-called hydroplaning phenomenon in which the wet paper web transfer belt 1B and the roll slip.

[0104] Furthermore, when applying the resin material to form the first resin layer 13B and the second resin layer 15B, the rate at which the resin material penetrates into the batt fibers and the reinforcing fiber substrate layer 11B is lower than when the batt fibers are not present. As a result, the thicknesses of the first resin layer 13B and the second resin layer 15B can be made sufficient, and the durability and strength of the wet paper web transfer belt 1 can be made sufficient.

[0105] On the other hand, when batt fibers are included in a resin layer such as the first resin layer 13B and the second resin layer 15B, the batt fibers absorb moisture and swell, which generally tends to cause warping at the ends of the wet paper web transfer belt. However, the wet paper web transfer belt 1B includes the reinforcing fiber substrate layer 11B as described above, which suppresses warping at the ends of the wet paper web transfer belt 1B.

[0106] (2.3. Other Modifications) In the above-described embodiment, the woven fabric included in the reinforcing fiber substrate layer 11 has a double structure, but the present invention is not limited to this, and may have a triple or more layer structure. In this case, it is sufficient that any two parallel warp or weft threads in the layered structure of the woven fabric have the above-described fineness relationship. Preferably, of the parallel warp or weft threads in the layered structure of the woven fabric, the fineness of the thread closest to the first surface (wet paper support side) is greater than the fineness of the thread closest to the second surface (roll side).

[0107] In addition, in the above-mentioned embodiment, the first warp thread 115 and the second warp thread 117 of the woven fabric contained in the reinforcing fiber substrate layer 11 have the above-mentioned fineness relationship, but the present invention is not limited to this, and the woven fabric contained in the reinforcing fiber substrate layer may be a weft multi-weave, and for two parallel weft threads, the fineness of the weft thread on the first surface side (wet paper carrying side) may be greater than the fineness of the weft thread on the second surface side (roll side).

[0108] In addition, in the second modified example described above, the first resin layer 13B and the second resin layer 15B containing batt fibers are formed on both sides of the reinforcing fiber base layer 11B, but the present invention is not limited to this, and a resin layer containing batt fibers may be formed on only one side of the reinforcing fiber base layer.

[0109] <4. Method of manufacturing papermaking belts> Next, some examples of preferred embodiments of the manufacturing method of the papermaking belt of the present invention described above will be described. In this embodiment, a manufacturing method of the wet paper web transfer belt 1 will be representatively described as an example of the papermaking belt. The wet paper web transfer belt 1 may be manufactured by any method. In the following, as a manufacturing method of the wet paper web transfer belt 1, a back coat inversion manufacturing method and a front coat penetration manufacturing method will be representatively described.

[0110] First, the back coat inversion manufacturing method will be described with reference to Figs. 9 and 10. Figs. 9 and 10 are schematic diagrams for explaining a preferred embodiment of the manufacturing method of the papermaking belt according to the present invention. First, as shown in Fig. 9, an endless reinforcing fiber substrate 111 is wound so as to contact two rolls 21 arranged in parallel. At this time, the reinforcing fiber substrate 111 is arranged so that the first warp thread 115 of the reinforcing fiber substrate 111 contacts the roll 21. Next, while rotating the roll 21, a resin material for forming the second resin layer 15 is discharged from the resin discharge port 25 of the coater onto the surface of the reinforcing fiber substrate 111 from the side where the second warp thread 117 of the reinforcing fiber substrate 111 is arranged, that is, from the outside of the reinforcing fiber substrate 111 currently wound, and the resin material is applied using the coater bar 23. Next, the applied resin material is cured by heating to form the second resin layer 15.

[0111] Next, as shown in FIG. 10, the reinforcing fiber substrate 111 is inverted and laid so that the formed second resin layer 15 comes into contact with the roll 21. Thereafter, the resin material constituting the resin 113 of the reinforcing fiber substrate layer 11 and the first resin layer 13 is discharged onto the surface of the reinforcing fiber substrate 111 from the resin discharge port 25 of the coater, and the resin material is applied using the coater bar 23. As a result, the resin material is impregnated into the reinforcing fiber substrate 111 to form the resin 113, and a precursor of the first resin layer 13 is formed on the reinforcing fiber substrate 111. Then, the obtained resin laminate including the reinforcing fiber substrate 111 is heat-cured to obtain a wet paper web transfer belt 1 in which the first resin layer 13, the reinforcing fiber substrate layer 11, and the second resin layer 15 are laminated in this order. If necessary, the first surface 131 of the first resin layer 13 and / or the second surface 151 of the second resin layer 15 may be polished using a polishing device.

[0112] Next, the surface coat penetration manufacturing method will be described with reference to Figs. 11 and 12. Figs. 11 and 12 are schematic diagrams for explaining a preferred embodiment of the manufacturing method of the papermaking belt according to the present invention. First, as shown in Fig. 11, an endless reinforcing fiber substrate 111 is wound so as to contact two rolls 21 arranged in parallel. At this time, the reinforcing fiber substrate 111 is arranged so that the second warp thread 117 of the reinforcing fiber substrate 111 contacts the roll 21. Next, while rotating the roll, a resin material is discharged from the resin discharge port 25 of the coater onto the surface of the reinforcing fiber substrate 111 from the side where the first warp thread 115 of the reinforcing fiber substrate 111 is arranged, that is, from the outside of the reinforcing fiber substrate 111 currently wound, and the resin material is applied using the coater bar 23. The applied resin material can penetrate the reinforcing fiber substrate 111. Therefore, in this embodiment, it is possible to form not only the resin 113 contained in the reinforcing fiber substrate 111, but also the resin that constitutes the second resin layer 15, and it is possible to form the reinforcing fiber substrate layer 11 and the second resin layer 15 simultaneously.

[0113] Next, as shown in Fig. 12, the resin material of the first resin layer 13 is applied to the outer surface of the formed reinforcing fiber substrate layer 11. Specifically, the resin material is discharged from a resin discharge port 25 while rotating the formed reinforcing fiber substrate layer 11 and the second resin layer 15 by a roll 21, and the resin material is applied to the outer surface of the reinforcing fiber substrate layer 11. At the same time, the applied resin material is uniformly applied using a coater bar 23. The resin material constituting each layer may be applied as a mixture with the above-mentioned inorganic filler.

[0114] Next, the applied resin material is dried and cured. As a result, a wet paper web transfer belt 1 is obtained in which the first resin layer 13, the reinforcing fiber substrate layer 11, and the second resin layer 15 are laminated in this order from the outer surface. If necessary, the first surface 131 of the first resin layer 13 and / or the second surface 151 of the second resin layer 15 may be polished using a polishing device.

[0115] The present invention has been described in detail above based on a preferred embodiment, but the present invention is not limited to this, and each component can be replaced with any component that can perform a similar function, or any component can be added.

[0116] In the above description, the papermaking belt is a wet paper web transfer belt, but the present invention is not limited thereto. For example, the papermaking belt of the present invention may be a shoe press belt or other papermaking belt. EXAMPLES

[0117] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0118] 1. Manufacturing of wet paper transport belts Example 1 The wet paper web transfer belt according to Example 1 was manufactured by the surface coating penetration method as follows.

[0119] (i) Preparation of reinforcing fiber substrate First, a double warp-ply woven fabric having the following structure was prepared as a reinforcing fiber substrate. First warp yarn: 3810dtex monofilament twisted yarn made of polyamide 6 (Two 370 dtex polyamide 6 monofilaments were twisted together, and these were twisted together to form five strands. The first twist was 2.1 times / cm, and the second twist was 1.2 times / cm.) Second warp: 3333 dtex multifilament twisted yarn made of polyamide 6 (68 polyamide 6 filaments of 22.1 dtex were twisted together and then twisted into two strands. The first twist was 0.7 times / cm and the second twist was 0.7 times / cm.)

[0120] Weft: 1582dtex monofilament twisted yarn made of polyamide 610 (Two 370 dtex polyamide 610 monofilaments were twisted together, and these were then twisted together. The first twist was 3.1 times / cm, and the second twist was 2.2 times / cm.) · Weave: Upper and lower warp threads 35 / 5cm, weft threads 40 / 5cm, double warp weave (3 / 1 1 / 7, equivalent to the weaves in Figures 2 to 4)

[0121] (ii) Formation of a laminate First, the prepared endless reinforcing fiber substrate was hung on two rolls arranged in parallel. At this time, the reinforcing fiber substrate was hung on the rolls so that the second warp thread of the reinforcing fiber substrate was in contact with the rolls. While rotating the rolls, a urethane composition was applied to the surface of the reinforcing fiber substrate where the first warp thread was exposed. As the urethane composition, a mixture of a urethane prepolymer obtained by reacting a mixture of 2,4-tolylene diisocyanate (2,4-TDI) and 2,6-tolylene diisocyanate (2,6-TDI) with polytetramethylene ether glycol (PTMG), and dimethylthiotoluenediamine (DMTDA) as a curing agent was used.

[0122] When this urethane composition was applied, the urethane composition impregnated the reinforcing fiber substrate and penetrated the reinforcing fiber substrate, and a reinforcing fiber substrate layer and a second resin layer on the roll side were simultaneously formed. Next, the urethane composition for the first resin layer on each wet paper support side was applied to the outer surface of the formed reinforcing fiber substrate layer, and the first resin layer was laminated. The laminate, which was the first resin layer, the reinforcing fiber substrate layer, and the second resin layer in this order from the outermost layer, was heated and dried to obtain a semi-finished wet paper transfer belt. (iii) Polishing and buffing The surface of the wet paper web carrying side of the wet paper web transfer belt (semi-finished product) was polished with an abrasive cloth of #80 to #600 appropriately set in a polishing device. In addition, in order to adjust the surface roughness of the wet paper web contact surface, buffing was appropriately performed, and the arithmetic mean roughness of the wet paper web carrying surface of the wet paper web transfer belt of each example was set to 0.3 to 20 μm. In this way, the wet paper web transfer belt of Example 1 was completed. The dimensions of the wet paper transport belt were 20 m in length and 700 mm in width.

[0123] Example 2 A wet paper web transfer belt according to Example 2 was produced in the same manner as in Example 1, except that the reinforcing fiber substrate was changed as follows. The reinforcing fiber substrate used in Example 2 used the same first warp yarns, second warp yarns, and weft yarns as the reinforcing fiber substrate used in Example 1, while having a double warp weave (3 / 1 1 / 3, corresponding to the weaves in Figures 5 to 7).

[0124] Example 3 A wet web transfer belt according to Example 3 was produced in the same manner as in Example 1, except that the reinforcing fiber substrate was changed as follows. The reinforcing fiber substrate used in Example 3 had the same first warp yarns, second warp yarns and weave structure as the reinforcing fiber substrate used in Example 1, while the following weft yarns were used. Weft: Polyamide 610 monofilament single yarn, 1059 dtex

[0125] Example 4 A wet web transfer belt according to Example 4 was produced in the same manner as in Example 2, except that batt fiber layers were formed by needling batt fibers on both sides of the reinforcing fiber substrate. In Example 4, short fibers made of polyamide 66 and having a cut length of 76 mm and a 22 dtex were used as the batt fibers, and the first resin layer was formed on the side (wet paper support side) at 100 g / m 2 100 g / m on the side where the second resin layer is formed (roll side) 2 The batt fiber layer was formed to have a basis weight of 100 g / m2.

[0126] Comparative Example 1 A wet paper web transfer belt according to Comparative Example 1 was produced in the same manner as in Example 4, except that the reinforcing fiber substrate was changed as follows. First and second warps: 2271 dtex monofilament twisted yarn made of polyamide 6 (Two 370 dtex polyamide 6 monofilaments were twisted together, and these were twisted together into three strands. The first twist was 2.7 times / cm, and the second twist was 2.1 times / cm.) Weft: 1582dtex monofilament twisted yarn made of polyamide 610 (Two 370 dtex polyamide 610 monofilaments were twisted together, and these were then twisted together. The first twist was 3.1 times / cm, and the second twist was 2.2 times / cm.) · Weave: Upper and lower warp threads 35 / 5cm, weft threads 40 / 5cm, double warp weave (3 / 1 1 / 3, equivalent to the weaves in Figures 5 to 7)

[0127] 2. Evaluation The produced wet paper web transfer belts of Examples 1 to 4 and Comparative Example 1 were evaluated for the degree of warping at the ends by the following procedure. First, a test piece S having a length of 3.2 m and a width of 22 cm was cut out from the wet paper web transfer belt of each of Examples 1 to 4 and Comparative Example 1. Next, the test piece S of each of Examples 1 to 4 and Comparative Example 1 was immersed in water for 24 hours in a room at a room temperature of 20±2°C and a humidity of 50±10%.

[0128] Next, the longitudinal ends of the test pieces S of each of Examples 1 to 4 and Comparative Example 1 were made endless with a sewing thread. Then, each test piece S was hung between two parallel rolls 30 as shown in Fig. 13. Next, the rolls 30 were rotated to rotate the test piece S twice at a cloth speed of 4 m / min, while water 41 was sprayed onto the surface of the test piece from a sprayer 40.

[0129] After the spraying, the tension acting on the test piece S was adjusted to 5 kN / m, and the roll 30 was stopped. Then, as shown in FIG. 14, a metal ruler 50 was placed against the second resin layer side of the test piece S and adjusted to be horizontal, and the distance between the metal ruler 50 and the part of the test piece S farthest from the metal ruler 50 was measured as the selvage curl amount d1, d2. Note that the end of the test piece S may be warped toward the roll side, i.e., toward the metal ruler 50. In this case, the distance between the highest point near the center of the width of the test piece S and the metal ruler 50 was measured as the selvage curl amount. The selvage curl amount was measured at four points, and the average value was taken as the selvage curl amount of the test piece S.

[0130] The above evaluation results are shown in Table 1 together with the configurations of the reinforcing fiber substrates of Examples 1 to 4 and Comparative Example 1.

[0131] [Table 1]

[0132] As shown in Table 1, the wet web transfer belts according to Examples 1 to 4 had smaller edge curls and less warping at the ends compared to the wet web transfer belt according to Comparative Example 1. In the above evaluation, a test piece S having a width of 22 cm was used, but a wet web transfer belt that is put into an actual papermaking machine has a width of several meters, and the warping at the ends increases in roughly proportion to this.

[0133] In addition, when comparing Examples 1 and 2 with Example 3, the wet paper transfer belts of Examples 1 and 2, which used twisted monofilament yarns as the weft yarns, had a smaller amount of edge curl compared to Example 3, which used a single monofilament yarn. Furthermore, when comparing Example 1 and Example 2, the wet paper transfer belt of Example 1, which used a reinforcing fiber base material having a 3 / 1 1 / 7 weave, had a smaller amount of edge curl than Example 2, which used a reinforcing fiber base material having a 3 / 1 1 / 3 weave. [Explanation of symbols]

[0134] 1, 1A, 1B Wet paper conveyor belt (papermaking belt) 11, 11B Reinforcement fiber substrate layer 111, 111A, 111B Reinforced fiber substrate 113 Resin 115, 115A First warp thread 117, 117A Second warp thread 119, 119A Weft 13, 13B First resin layer 131, 131B First surface (wet paper contact surface) 151, 151B Second resin layer (roll contact surface)

Claims

1. A papermaking belt used in a papermaking machine, having a first surface on which a wet paper web is placed and a second surface opposite to the first surface, A reinforcing fiber substrate layer including at least one layer of woven fabric is provided. At least one layer of the woven fabric has a two or more layered structure, The overlapping structure has first and second yarns arranged in parallel, the first thread is disposed closer to the first surface than the second thread, and the second thread is disposed closer to the second surface than the first thread; A papermaking belt, wherein the first yarn has a fineness greater than the fineness of the second yarn.

2. 2. The papermaking belt of claim 1, wherein the second yarns are crimped.

3. 2. The papermaking belt of claim 1, wherein the second yarn is a multifilament twisted yarn.

4. The papermaking belt of claim 1 , wherein the first yarns and the second yarns are disposed along the machine direction of the papermaking belt.

5. 2. The papermaking belt of claim 1, which does not have a batt fiber layer.

6. The woven fabric having the overlapping structure further includes a third yarn woven with the first yarn and the second yarn, 2. The papermaking belt of claim 1, wherein the third yarn is a twisted monofilament yarn.

7. The woven fabric having the overlapping structure further includes a third yarn woven with the first yarn and the second yarn, the overlapping structure has repeating units that can simultaneously form a repeat in which the third yarn passes over the first surface side of K first yarns and over the second surface side of L first yarns, and a repeat in which the third yarn passes over the first surface side of M second yarns and over the second surface side of N second yarns, 2. The papermaking belt according to claim 1, which satisfies the relationship K / L≧N / M.

8. The woven fabric having the overlapping structure further includes a third yarn woven with the first yarn and the second yarn, 2. The papermaking belt according to claim 1, wherein the number of intersections between the first yarn and the third yarn in the complete design is greater than the number of intersections between the second yarn and the third yarn in the complete design.

9. 2. The papermaking belt according to claim 1, which is a wet paper web transfer belt.

10. 2. The papermaking belt according to claim 1, which is a shoe press belt.

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