Felt for papermaking and method for producing the same

Abstract

The present invention provides a papermaking felt having a highly productive laminated structure using two or more plain woven base fabrics, in which no opening occurs when a flocked fiber layer is set or in use, and base fabrics can be bonded to each other, and a method for manufacturing the same. A papermaking felt characterized in that it comprises a combination of two or more base fabrics directly overlapped with each other, which are formed by MD wires in the felt travel direction (MD direction) and CD wires in the felt transverse direction (CD direction) and have a joint formed by a first MD end portion and a second MD end portion, and for all base fabrics having joints, when the maximum distance in the MD direction of the joints of the base fabrics is x (cm) and the minimum distance is y (cm), the following formulas (1) and (2) are satisfied: x≤750 (1), 10≤y (2).

Description

Technical Field

[0001] The present invention relates to a felt for papermaking and a method for producing the same. Background Art

[0002] A papermaking machine that removes water from the raw material of paper generally has a wire section, a press section, and a drying section. These wire sections, press sections, and drying sections are arranged in sequence along the conveying direction of the wet paper. The wet paper has a certain width in a direction (CD: Cross Machine Direction) perpendicular to the traveling direction (MD direction: Machine Direction) of the papermaking machine and moves in the papermaking machine in a belt shape. It is successively conveyed by papermaking tools installed in the wire section, press section, and drying section, while being squeezed out of water, and finally dried in the drying section.

[0003] The press device disposed in the press section is provided with a plurality of press devices arranged in series along the conveying direction of the wet paper. Each press device has an endless felt or a felt formed by connecting an end-shaped felt on a papermaking machine to form an endless felt, and a pair of rollers disposed up and down facing each other so as to sandwich a part of the felt therebetween (i.e., a roller press) or a roller and a cylindrical boot with a shoe plate inside (i.e., a shoe press), and the wet paper conveyed by the felt moving in the same direction at substantially the same speed is pressed by the felt and the rollers or the rollers and the cylindrical boot with a shoe plate inside, so that moisture is continuously removed from the wet paper.

[0004] The properties required of felt used in a pressing device include water squeezeability, smoothness, and migration stability. Water squeezeability refers to the ability to remove moisture from wet paper. In order to achieve this property, it is important that the felt has good compression recovery properties, that is, when the felt is not pressurized, there is space (void volume) in the felt for removing the moisture, and when the felt is pressurized, the density of the felt reaches the maximum, the volume of the space decreases, and the moisture is released to the outside of the felt. In addition, it is also important to maintain the water squeezeability during the use of the felt and that the removed moisture does not return to the wet paper again.

[0005] Smoothness refers to the smoothness of the wet paper surface and the felt surface (including the felt surface under pressure). The wet paper is pressurized through the felt, so the surface state of the felt is transferred to the wet paper surface. Therefore, in order to make the wet paper surface smooth, the felt surface (including the felt surface under pressure) must be smooth.

[0006] The migration stability refers to the fact that the endless felt arranged in the pressing device migrates stably without opening, breaking, deflection, distortion, vibration, fluctuation, etc.

[0007] There are various types of paper, such as newspaper, book paper, cardboard, household paper, etc., and there are also various types of papermaking machines for manufacturing these papers. At present, various types of felts for papermaking are manufactured in conjunction with these papers and papermaking machines, but generally speaking, the felt is formed by integrating a flocking fiber layer of a non-woven fiber material with a base fabric layer. The base fabric layer can be a woven fabric composed of, for example, monofilaments, monofilament yarns, multifilaments or multifilament yarns, and the woven fabric can be a single-layer product or a multi-layer product, or it can be said that it is a laminated structure obtained by stacking them. The yarn is generally a product obtained by extrusion molding of any one of the synthetic polymer resins such as polyamide resins or polyester resins used for this purpose by practitioners in the field of papermaking tool technology, animal fibers such as wool, and plant fibers such as cotton and linen.

[0008] The base fabric layer includes various types of woven fabrics, such as those woven endlessly on a loom (tubular weaving), or those woven with ends of a plain weave with ends sewn together to form an endless shape, or those woven with ends joined together in the mechanical transverse direction or the mechanical direction to form an endless shape. Among them, the base fabric woven endlessly on a loom (tubular weaving) or the base fabric woven with ends joined together in the mechanical transverse direction to form an endless shape (spiral base fabric) is called an endless base fabric.

[0009] Among them, the base fabric layer (papermaking felt) manufactured by tubular weaving has a seamless continuous surface and is therefore smooth. However, various papermaking machines have various sizes, so the base fabric layer corresponding to each needs to be manufactured in a completely customized manner. Therefore, in order to manufacture the base fabric layer by tubular weaving, each time the size is changed, it is necessary to change the loom settings slightly, which is very poor in productivity and yield.

[0010] In contrast, as an efficient method for manufacturing felt for papermaking, a method for joining the ends of a plain woven base fabric in the MD direction to each other is proposed (Patent Document 1). Specifically, the following method is disclosed: before providing a flocking fiber layer, the ends of the base fabric in the MD direction from which the horizontal yarns are removed are overlapped and pressed to join the ends to each other. It is also disclosed that the base fabric is used on the wet paper side and a laminated structure of a tubular woven base fabric is used on the papermaking machine side.

[0011] Prior art literature

[0012] Patent Literature

[0013] Patent Document 1: Japanese Patent Publication No. 2006-510812

[0014] Summary of the Invention

[0015] Technical problem to be solved by the invention

[0016] When the papermaking felt obtained by the production method disclosed in the above prior art has a laminated structure using a tubular woven base fabric on the papermaking machine side, productivity is extremely poor because half of the base fabric used is a tubular woven base fabric.

[0017] In addition, in the case of a laminated structure using only a plain woven base fabric, an opening of the joint may occur when the flocking fiber layer is set or the papermaking felt is used. The opening referred to in this specification means that the flocking fiber layer is set or the papermaking felt is used, and the joint opens. On the other hand, if a low tension is used when the flocking fiber layer is set in order to prevent an opening, the length of one of the base fabrics of more than two base fabrics will be left over, and the base fabrics cannot be bonded to each other, so the length of the base fabrics may not be adjusted, resulting in a decrease in productivity.

[0018] In the case of a felt with a laminated structure of more than 3 base fabrics, productivity can be improved by using more than half of the flat woven base fabrics. Specifically, in the case of 3 base fabrics, productivity can be improved by using 2 or 3 flat woven base fabrics. In the case of a felt with a laminated structure of more than 3 base fabrics, in addition to the flat woven base fabric, an endless base fabric can also be used. In this case, as with the felt with a laminated structure using only the flat woven base fabric, openings in the joints may occur when the flocking fiber layer is set or when the felt for papermaking is used. In addition, if low tension is used when setting the flocking fiber layer in order to prevent openings, the length of the base fabric may not be adjusted, resulting in reduced productivity.

[0019] An object of the present invention is to provide a papermaking felt having a laminated structure using two or more plain woven base fabrics, in which openings are suppressed and productivity is high, and a method for producing the same.

[0020] Technical solutions adopted to solve technical problems

[0021] After careful study, the inventors found that by making the distance of the joint in the MD direction within a certain range when setting the flocking fiber layer, the tension of the joints of multiple plain woven base cloths can be fully guaranteed until the flocking fiber layer is set or the felt for papermaking is used, thereby solving the problem of the invention in this application.

[0022] <1> A felt for papermaking, characterized in that it comprises a combination of two or more base fabrics directly overlapped each other, each of which is formed of MD wires in the felt running direction (MD direction) and CD wires in the felt transverse direction (CD direction) and has a joint portion formed by joining a first MD end portion and a second MD end portion, wherein for all the base fabrics having the joint portion, when the maximum distance in the MD direction of the joint portion of the base fabric is x (cm) and the minimum distance is y (cm), the following formulas (1) and (2) are satisfied:

[0023] x≤750 (1),

[0024] 10≤y (2).

[0025] <2> The papermaking felt according to <1>, wherein x satisfies the following formula (3):

[0026] x≤500 (3).

[0027] <3> The papermaking felt according to <1> or <2>, wherein y satisfies the following formula (4):

[0028] 51≤y (4).

[0029] <4> The papermaking felt according to any one of <1> to <3>, comprising two base fabrics having a joining portion.

[0030] <5> The papermaking felt according to any one of <1> to <3>, comprising three or more base fabrics having joined portions, wherein distances of the joined portions in the MD direction of the base fabrics are unequal to each other.

[0031] <6> The papermaking felt according to any one of <1> to <5>, further comprising an endless base fabric.

[0032] <7> The papermaking felt according to any one of <1> to <6>, wherein the ends in the MD direction of the base fabric having the joining portion are joined by welding.

[0033] <8> The papermaking felt according to any one of <1> to <7>, comprising a flocked fiber layer of a nonwoven fiber material.

[0034] <9> A method for producing a felt for papermaking, comprising:

[0035] (a) a step of directly overlapping two or more base fabrics of a combination formed by MD wires in a felt running direction (MD direction) and CD wires in a felt transverse direction (CD direction) and having a joint portion formed by a first MD end portion and a second MD end portion joined to each other;

[0036] (b) a step of arranging base fabrics so that, for all base fabrics having junctions, the maximum distance in the MD direction of the junctions of the base fabrics is x (cm) and the minimum distance is y (cm), the following equations (1) and (2) are satisfied:

[0037] x≤750 (1),

[0038] 10≤y (2);

[0039] (c) A step of integrating the base fabric and the flocked fiber layer overlapped in the step (b).

[0040] <10> The manufacturing method according to <9>, comprising:

[0041] In step (b), a step of overlapping the base fabrics in such a manner that x satisfies the following formula (3):

[0042] x≤500 (3).

[0043] <11> The manufacturing method according to <9> or <10>, comprising:

[0044] In step (b), a step of overlapping the base fabrics in such a manner that y satisfies the following formula (4):

[0045] 51≤y (4).

[0046] Effects of the Invention

[0047] The above structure can provide a papermaking felt having a laminated structure with good productivity using two or more plain woven base fabrics, in which no opening occurs when the flocking fiber layer is set or the papermaking felt is used, and a method for manufacturing the same can be provided.

[0048] Brief description of the attached figure

[0049] Figure 1 It is a schematic diagram of a base fabric of the present invention.

[0050] Figure 2 It is a schematic diagram of a product formed by overlapping two base fabrics whose ends in the MD direction are joined in the manufacturing process of the present invention.

[0051] Figure 3 It is a schematic diagram of a product formed in the manufacturing process of the present invention, in which three base fabrics are overlapped and the ends thereof are joined in the MD direction.

[0052] Figure 4 It is a schematic diagram of a product formed in the manufacturing process of the present invention, in which two base fabrics whose ends are joined in the MD direction and one endless base fabric are overlapped.

[0053] Modes for Carrying Out the Invention

[0054] Hereinafter, although the embodiment of the base fabric for papermaking felt and the manufacturing method thereof of the present invention will be described using drawings, the present invention is not limited to these examples.

[0055] In addition, unless otherwise defined in this specification, all technical terms and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art. All patents, applications and other publications (including information available on the Internet) referenced in this specification are incorporated herein by reference in their entirety.

[0056] The base fabric used for the papermaking felt of the present invention is formed of MD wires in the felt running direction (MD direction) and CD wires in the felt cross direction (CD direction).

[0057] The MD / CD direction of the plain woven base fabric (with end shape) is Figure 1 The arrows (MD / CD) indicate that when a papermaking felt is used in a papermaking machine, the MD direction is defined as the travel direction (rotation direction) of the felt, and the CD direction is defined as the direction transverse to the travel direction of the felt. Figure 1 The figure shows a first MD direction end 1 and a second MD direction end 2.

[0058] The MD / CD direction in the endless base fabric (endless state) is Figure 4 The wet paper side base fabric (the outermost base fabric) is indicated, and the running direction of the felt and the direction transverse to the running direction are defined in the same way as the plain woven base fabric.

[0059] The papermaking felt of the present invention is

[0060] A papermaking felt combination comprising two or more base fabrics (hereinafter also referred to as "base fabrics with a joining portion") formed by MD wires in the felt travel direction (MD direction) and CD wires in the felt transverse direction (CD direction) and having a joining portion formed by a first MD direction end portion and a second MD direction end portion joined together.

[0061] The papermaking felt of the present invention is characterized in that, for all base fabrics having a joint portion, the following formula (1) is satisfied when the maximum distance of the joint portion in the MD direction is x (cm):

[0062] x≤750 (1).

[0063] When x exceeds 750, openings are easily generated when the flocking fiber layer is set or the papermaking felt is used, and the length of the base fabric cannot be adjusted, which is not ideal. Here, the length of the base fabric cannot be adjusted means that the length of one side of the base fabric is redundant, resulting in wrinkles.

[0064] The distance between the joints in this specification refers to the shortest distance along the MD direction of the wet paper side base fabric when the joints of the base fabrics having the joints are moved in the vertical direction (the thickness direction of the base fabric) and it is assumed that they are all on the wet paper side base fabric (the outermost base fabric). In addition, when the joint has a width in the MD direction, it refers to the distance between the joints based on the center of the MD direction of the joint having the width.

[0065] The papermaking felt of the present invention is characterized in that, for all base fabrics having a joint portion, the maximum distance of the joint portion in the MD direction is 750 cm or less, preferably 500 cm or less, that is, the above formula (1) is satisfied, preferably the following formula (3) is satisfied:

[0066] x≤500 (3).

[0067] The papermaking felt of the present invention is characterized in that, for all base fabrics having a joint portion, the following formula (2) is satisfied when the minimum distance of the joint portion in the MD direction is y (cm):

[0068] 10≤y (2).

[0069] When y is less than 10, openings may occur, which is not ideal.

[0070] The papermaking felt of the present invention is characterized in that, for all base fabrics having a joint portion, the minimum distance of the joint portion in the MD direction is 10 cm or more, preferably 51 cm or more, that is, the above formula (2) is satisfied, preferably the following formula (4) is satisfied:

[0071] 51≤y (4).

[0072] Since the joint of the base fabric with the joint is close to the MD direction, the tension of the part is sufficient, and no opening will occur when the flocking fiber layer is set or when the papermaking felt is used. When the flocking fiber layer is set, tension is applied to make the base fabric longer than other base fabrics as tight as other base fabrics, but the joint without the flocking fiber layer may have a drop in tension or opening. However, the papermaking felt of the present invention applies tension to the joints that are close in the MD direction after the flocking fiber layer is set, so this problem will not occur.

[0073] When the distance in the MD direction of the joint of the base fabric is made closer, the flocking fiber layer is set earlier at the joint, and the length of the base fabric without the flocking fiber layer is longer. Since the length of each base fabric can be made equal in this state, the tension applied can be lower. In this way, the tension drop and the opening of each joint can be prevented.

[0074] As a result, a papermaking felt having a highly productive laminated structure can be obtained in which no opening occurs when the flocking fiber layer is set or during the use of the papermaking felt, and the base fabrics can be bonded to each other using two or more plain woven base fabrics (base fabrics having a joint portion provided by bonding). Here, in the papermaking felt of the present invention, for all the base fabrics used, two pieces can be overlapped, or three or more pieces can be overlapped. In the case where two base fabrics are overlapped, only the base fabric having a joint portion is used. In addition, in the case where three or more base fabrics are overlapped, only the base fabric having a joint portion can be used, or an endless base fabric can be used. In the case of using an endless base fabric, the papermaking felt of the present invention contains two or more base fabrics having a joint portion that are directly overlapped with each other.

[0075] On the other hand, when the distance between the joints of each base fabric is very close, vibration may be caused during the use of the papermaking felt. The flocking fiber layer is arranged on the base fabric in a repeated manner along the CD direction while the base fabric is moved in the MD direction. If the overlapping spacing of the flocking fiber layer at this time is in the same range as the distance between each joint, it may become a cause of vibration. On the other hand, the overlapping spacing of the flocking fiber layer is preferably in the range of 8 to 50 cm.

[0076] When tension is applied, the bonding force (shear tension) between the base fabric and the flocking fiber layer between the joints plays a role in supplementing the tension of the joints. Therefore, by making the distance between the joints above a certain distance, it is not easy to produce an opening in the joints, so it is preferred. Generally speaking, the bonding force (shear tension) between the base fabric and the flocking fiber layer between the joints plays a role in supplementing the tension of the joints when the distance between the joints is more than 10 cm.

[0077] As described above, the papermaking felt of the present invention may include two base fabrics having a joint portion, or may include three or more base fabrics.

[0078] In the case where there are more than 3 base fabrics with a joint, if the period of the joint is the same, it may become a cause of vibration, so the papermaking felt of the present invention is preferably that the distances in the MD direction of the joint of the base fabric are not equal to each other. In this specification, the distances in the MD direction of the joint of the base fabric in the papermaking felt are not equal to each other, which means that for the combination of 2 joints of the base fabric with a joint of more than 3 pieces, when all the distances between the joints are calculated, the combination with equal distances between the joints does not exist. For example, in the case where there are 4 base fabrics with a joint, there are 4 joints, and among the 5 kinds of combinations of 2 joints that can be considered (when each joint is set to a, b, c, d, between ab and bc, between ab and cd, between ab and bd, between ac and cd, between bc and cd), it is better that the combination with equal distances between the joints does not exist.

[0079] By making the distance of the joints of each base cloth in the MD direction within a certain range, when there are three or more base cloths with joints, the distances of all the joints are unequal, so it is less likely to cause vibration and opening of the joints, which is preferred.

[0080] As described above, the papermaking felt of the present invention may have a flocked fiber layer. The material constituting the flocked fiber layer is not particularly limited, but a nonwoven fiber material is preferably used.

[0081] The length of the papermaking felt of the present invention in the MD direction is preferably 1550 cm to 40000 cm, more preferably 2000 cm to 20000 cm. The length of the papermaking felt in the MD direction as used herein refers to the length of the wet paper side base fabric constituting the papermaking felt along the MD direction around the circumference.

[0082] By making the length of the felt for papermaking in the MD direction within the said range, when the flocking fiber layer is provided, the length of the base cloth without the flocking fiber layer is long. In this state, the lengths of the base cloths can be made equal, and a lower tension can be applied, which can prevent the tension drop and opening of each joint, and is therefore preferred.

[0083] As specific forms of the papermaking felt of the present invention, the following forms (a), (b), and (c) can be exemplified:

[0084] (a) a papermaking felt having two overlapping base fabrics whose first MD direction end portion and second MD direction end portion are joined;

[0085] (b) a papermaking felt having three or more base fabrics whose first MD direction end portion and second MD direction end portion are joined and stacked;

[0086] (c) Two or more base fabrics whose first MD direction end portion and second MD direction end portion are joined together are directly stacked, and then a papermaking felt having an endless base fabric is stacked.

[0087] When a papermaking felt is produced by overlapping two base fabrics having a joint portion, for example Figure 2 As shown, the joint of base fabric B' and the joint of base fabric B" can be overlapped in the MD direction. The distance of the joint can be considered as the closer (smaller) side and the farther (larger) side on the opposite side. In the papermaking felt of the present invention, the distance of the joint is defined as the closer (smaller) side. For example, when the maximum distance of the joint in the MD direction is less than 750 cm, the distance to the closer side can be less than 750 cm. In the case of two base fabrics, the distance 5 can be the maximum distance x or the minimum distance y.

[0088] When a papermaking felt is produced by stacking three or more base fabrics having a joint portion, for example Figure 3As shown, the joints of the three base fabrics B', B", and B'" can be overlapped in the MD direction. As with the case of two base fabrics, the three joints are arranged within 750cm, and the distance between the joints farthest apart in the MD direction is the maximum distance x (cm). Figure 3 In the case of , the distance 6 between the joint of the wet paper side base fabric and the joint of the base fabric between the wet paper side base fabric and the papermaking machine side base fabric (the innermost base fabric) is the maximum distance x, and the distance 7 between the joint of the papermaking machine side base fabric and the joint of the base fabric between the wet paper side base fabric and the papermaking machine side base fabric is the minimum distance y. Here, the distance 6 is greater than the distance between the joint of the wet paper side base fabric and the joint of the papermaking machine side base fabric, and the distance 7 is smaller than the distance between the joint of the wet paper side base fabric and the joint of the papermaking machine side base fabric.

[0089] When a papermaking felt is produced by overlapping two or more base fabrics having a joint portion with an endless base fabric, for example Figure 4 As shown, the papermaking machine side base fabric can be directly overlapped with the base fabric between the wet paper side base fabric and the papermaking machine side base fabric, and then the wet paper side base fabric can be overlapped with a tubular woven base fabric. Two base fabrics with a joint can overlap the joint of base fabric B" and the joint of base fabric B"' in the MD direction. In this case, as in the case of overlapping two base fabrics to manufacture a felt for papermaking, the closer (smaller) side is defined as the distance of the joint, and the distance 5 can be the maximum distance x or the minimum distance y.

[0090] In a felt having a laminated structure of more than three base fabrics, when two or more base fabrics having a joint portion are overlapped with an endless base fabric to produce a felt for papermaking, the positions of the base fabrics can be any position as long as at least two base fabrics having a joint portion are directly overlapped, and the other base fabrics having a joint portion and the endless base fabric can be at any position.

[0091] In addition, when there is a group of two or more base fabrics having a joint portion that directly overlap each other and a base fabric having a joint portion that overlaps each other and is not adjacent to each other, for all base fabrics having a joint portion, the distance in the MD direction of the joint portion can be within the range that satisfies equations (1) and (2).

[0092] The same is true for the case where two or more base fabrics with joints overlap directly, and the distance in the MD direction of the joints is within the range satisfying equations (1) and (2) for all base fabrics with joints. For example, in a felt with a laminated structure of five base fabrics, two base fabrics with joints, an endless base fabric, and two base fabrics with joints overlap, and the maximum distance in the MD direction of the joints is less than 750 cm, all four joints can be arranged within 750 cm.

[0093] Similarly, in the case where two or more base fabrics having a joint portion are overlapped in addition to directly overlapping each other, the distance in the MD direction of the joint portion can be within the range satisfying equations (1) and (2) for all base fabrics having a joint portion.

[0094] The ends of the base fabric having the joining portion in the MD direction can be joined by sewing with a sewing machine, stitching, adhesive, needle punching, melting, welding, etc. Among them, joining by welding is preferably performed from the viewpoint of ease of operation.

[0095] Furthermore, the joining methods of the plurality of base fabrics may be the same or different.

[0096] For all base fabrics used in the papermaking felt of the present invention, the constituent material of the fibers constituting the MD wires and CD wires of the base fabric is preferably a thermoplastic resin. For example, polyethylene resin, polypropylene resin, polystyrene resin, acrylic resin, such as polyethylene terephthalate, polyamide resin, acetal resin, carbonate resin, etc. can be used, among which polyamide resin is preferred. In addition, the constituent materials of the MD wires and CD wires may be the same or different.

[0097] The fiber constituting the MD wire and the CD wire may be in the form of monofilament, multifilament, staple fiber, or processed yarns such as textured yarns, bulked yarns, and stretched yarns subjected to crimping and bulking processes, and twisted yarns obtained by twisting these yarns. The cross-sectional shape of the fiber may be circular, approximately elliptical, polygonal, approximately star-shaped, approximately rectangular, and the like.

[0098] The fineness of the fibers constituting the MD and CD yarns is not particularly limited, but in the case of monofilaments, it is preferably from 89 to 2240 dtex (0.10 to 0.50 mm), more preferably from 200 to 1440 dtex (0.15 to 0.40 mm).

[0099] For all base fabrics used in the papermaking felt of the present invention, the MD wires and CD wires constituting the base fabric may be either one type or two or more types.

[0100] The base fabric may be a single-layer texture or a multi-layer texture, and the weaving structure is not particularly limited, and may be any of other structures such as plain weave, twill weave, satin weave, fancy weave, and combinations thereof. In addition, it is not limited to woven fabrics, and a lattice-shaped raw material in which chain warp yarns and chain weft yarns are arranged up and down may also be used.

[0101] For all base fabrics used in the papermaking felt of the present invention, the mass per unit area of ​​the base fabric is not particularly limited, but can generally be set to 100 to 800 g / m 2 , preferably 150 to 500 g / m 2The thickness of the base fabric is not particularly limited, but is usually 0.4 to 1.3 mm, preferably 0.6 to 1.1 mm. The density of the base fabric is not particularly limited, but is usually 0.25 to 0.55 g / cm 3 , preferably 0.35 to 0.45 g / cm 3 .

[0102] The base fabric of the papermaking felt of the present invention, except the base fabric with the joint portion, is not particularly limited, and may be any of a seamed base fabric, a plain woven stitched base fabric, a tubular woven base fabric, a spiral base fabric, and a non-woven base fabric. Among them, an endless base fabric such as a tubular woven or spiral base fabric is preferred from the viewpoint of smoothness.

[0103] As a preferred form of the endless base fabric, the constituent materials of the fibers constituting the MD wires and the CD wires, the form of the fibers, the fineness of the fibers, and the mass per unit area of ​​the base fabric can be adopted.

[0104] For all base fabrics used in the papermaking felt of the present invention, the size of the base fabric is not particularly limited as long as the size of the final product (papermaking felt) can be satisfied by overlapping a combination of base fabrics including two or more plain woven base fabrics whose MD direction ends are joined and directly overlapped.

[0105] The present invention also relates to a method for manufacturing a felt for papermaking, comprising: (a) directly overlapping two or more base fabrics formed of MD wires in a felt running direction (MD direction) and CD wires in a felt transverse direction (CD direction) and having a joint portion formed by joining MD end portions formed by a first MD end portion and a second MD end portion;

[0106] (b) a step of arranging base fabrics so that, for all base fabrics having junctions, the maximum distance in the MD direction of the junctions of the base fabrics is x (cm) and the minimum distance is y (cm), the following equations (1) and (2) are satisfied:

[0107] x≤750 (1),

[0108] 10≤y (2);

[0109] (c) A step of integrating the base fabric and the flocked fiber layer overlapped in the step (b).

[0110] The manufacturing method of the present invention preferably comprises: in the step (b), a step of overlapping the base fabrics so that x satisfies the following formula (3):

[0111] x≤500 (3).

[0112] The manufacturing method of the present invention preferably comprises: in the step (b), a step of overlapping the base fabrics so that y satisfies the following formula (4):

[0113] 51≤y (4). Example

[0114] Hereinafter, the papermaking felt of the present invention will be described in detail using Examples, but these Examples do not limit the present invention in any way.

[0115] Using the base fabrics with joints shown below, the papermaking felts of Examples 1 to 4 and Comparative Examples 1 and 2 were prepared. The ends in the MD direction were joined by ultrasonic welding, and two base fabrics with joints were overlapped. After flocking fiber layers were provided at the two joints, a predetermined tension was applied to make the lengths of the base fabrics equal.

[0116] Table 1 shows the distance in the MD direction of the joint of the base fabric, the presence or absence of an opening in the joint after the flocking fiber layer is provided, whether the base fabric length can be adjusted, and the overall value (OA value) of the vibration test.

[0117] Base fabric size: length (MD direction) 1550cm x width (CD direction) 500cm

[0118] [Table 1]

[0119] Table 1

[0120]

[0121] In addition, the following base fabrics with joints were used to make papermaking felts of Examples 5 to 10 and Comparative Examples 3 and 4. The ends in the MD direction were joined by ultrasonic welding, and three base fabrics with joints were overlapped. After the flocking fiber layer was set at the three joints, a predetermined tension was applied to make the lengths of the base fabrics equal. Among the three joints, the joint closest to the traveling direction was set as joint 1, followed by joint 2 and joint 3.

[0122] Table 2 shows the distance in the MD direction of the joint of the base fabric, the presence or absence of an opening in the joint after the flocking fiber layer is provided, whether the base fabric length can be adjusted, and the overall value (OA value) of the vibration test.

[0123] Base fabric size: length (MD direction) 1550cm x width (CD direction) 500cm

[0124] [Table 2]

[0125] Table 2

[0126]

[0127] In addition, the following base fabrics with joints and endless base fabrics were used to produce papermaking felts of Examples 11 to 14 and Comparative Examples 5 and 6. The ends of the base fabrics with joints in the MD direction were joined by ultrasonic welding, and two base fabrics were directly overlapped, and then a tubular woven base fabric was overlapped as a wet paper side base fabric. After the flocking fiber layer was set at the two joints, a predetermined tension was applied to make the lengths of the base fabrics equal.

[0128] Table 1 shows the distance in the MD direction of the joint of the base fabric, the presence or absence of an opening in the joint after the flocking fiber layer is provided, whether the base fabric length can be adjusted, and the overall value (OA value) of the vibration test.

[0129] Base fabric size: length (MD direction) 1550cm x width (CD direction) 500cm

[0130] [Table 3]

[0131] Table 3

[0132]

[0133] Whether the opening and base fabric length in Tables 1, 2, and 3 can be adjusted is an indicator for evaluating manufacturability. Regarding the evaluation method of the opening, after the flocking fiber layer is set, the flocking fiber layer on the joint surface of the wet paper side base fabric and the back of the joint of the papermaking machine side base fabric is removed, and the presence or absence of the opening of the joint is confirmed by naked eyes.

[0134] Regarding whether the length of the base fabric can be adjusted, after setting the flocking fiber layer, a tension of 3 kN / m was applied to 2 or 3 joints. When one circle of the flocking fiber layer was removed, it was visually confirmed whether there was any excess length of the base fabric (wrinkles, etc.).

[0135] Vibration is an indicator for evaluating running stability. The evaluation method is to measure the acceleration (overall value) in the pressure direction of FFT analysis at a speed of 1000m / min and a pressure of 100kg / cm. Generally speaking, when this value is less than 0.3, the vibration is considered good.

[0136] As can be seen from the table, by making the maximum distance of the joint in the MD direction of the base fabric with the joint part less than 750 cm and the minimum distance more than 10 cm, the base fabrics on the wet paper side and the papermaking machine side did not open. Regarding the adjustment of the base fabric length, when the maximum distance in the MD direction of the joint part is less than 750 cm, the length of each base fabric can be equal. Regarding vibration, it can be seen that when the minimum distance in the MD direction of the joint part is more than 51 cm and there are three base fabrics with the joint part, the distances in the MD direction of the joint part are not equal to each other, and the travel stability is good.

[0137] Explanation of symbols

[0138] B Base fabric

[0139] B' Wet paper side base fabric (base fabric with joints)

[0140] B” Papermaking machine side base fabric (base fabric with joints)

[0141] B"' Base fabric between the wet paper side base fabric and the papermaking machine side base fabric (base fabric with a joint)

[0142] B”” Wet paper side base fabric (cylindrical woven base fabric)

[0143] 1 First MD direction end area

[0144] 2 Second MD direction end area

[0145] 3 Wet paper side base cloth joint

[0146] 4 Jointing section of base fabric on the papermaking machine side

[0147] 5 Distance of the joint in the MD direction

[0148] 6 The joint between the wet paper side base fabric and the papermaking machine side base fabric

[0149] 7 Maximum distance of the joint in the MD direction

[0150] 8 Minimum distance of the joint in the MD direction

Claims

1. A felt for papermaking, characterized in that: A combination of two or more base fabrics directly overlapped with each other, which are formed by MD wires in the felt travel direction, i.e., the MD direction, and CD wires in the felt transverse direction, i.e., the CD direction, and have a joint formed by joining the MD direction ends formed by the first MD direction end and the second MD direction end, and for all the base fabrics having joints, when the maximum distance in the MD direction of the joints of the base fabrics is set to x and the minimum distance is set to y, the following formulas (1) and (2) are satisfied: x≤750 (1)， 10≤y (2)； The units of x and y are cm; The length of the papermaking felt in the MD direction is 1550 cm or more and 40000 cm or less; And among them, The fiber constituent material of the MD wire and CD wire is thermoplastic resin. The fiber is in the form of monofilament, multifilament, staple yarn or processed yarn, or twisted yarn obtained by twisting these yarns. The base fabric is a single-layer texture or a multi-layer texture.

2. The papermaking felt according to claim 1, wherein x satisfies the following formula (3): x≤500 (3)。 3. The papermaking felt according to claim 1 or 2, wherein y satisfies the following formula (4): 51≤y (4)。 4. The papermaking felt according to claim 1 or 2, wherein Contains 2 base fabrics with joints.

5. The papermaking felt according to claim 1 or 2, wherein The present invention comprises three or more base fabrics having joints, wherein the distances of the joints in the MD direction of the base fabrics are unequal to each other.

6. The papermaking felt according to claim 1 or 2, wherein Also includes an endless base fabric.

7. The papermaking felt according to claim 1 or 2, wherein The ends in the MD direction of the base fabric having the joining portion are joined by welding.

8. The papermaking felt according to claim 1 or 2, wherein A flocked fiber layer having a non-woven fiber material.

9. A method for producing a felt for papermaking, wherein: include: (a) a step of directly overlapping each base fabric of a combination of two or more base fabrics formed by MD wires in the felt travel direction, i.e., the MD direction, and CD wires in the felt transverse direction, i.e., the CD direction, and having a joint portion formed by joining the MD end portions formed by the first MD end portion and the second MD end portion; (b) a step of arranging base fabrics so that, for all base fabrics having junctions, the maximum distance in the MD direction of the junctions of the base fabrics is x and the minimum distance is y, the following equations (1) and (2) are satisfied: x≤750(1)、 10≤y (2)； Where, the units of x and y are cm; The length of the papermaking felt in the MD direction is 1550 cm or more and 40000 cm or less; (c) a step of integrating the base fabric and the flocked fiber layer overlapped in step (b); And among them, The fiber constituent material of the MD wire and CD wire is a thermoplastic resin. The fiber is in the form of monofilament, multifilament, staple yarn or processed yarn, or twisted yarn obtained by twisting these yarns. The base fabric is a single-layer texture or a multi-layer texture.

10. The manufacturing method according to claim 9, wherein: include: In step (b), a step of overlapping the base fabrics in such a manner that x satisfies the following formula (3): x≤500 (3)。 11. The manufacturing method according to claim 9 or 10, wherein: include: In step (b), a step of overlapping the base fabrics in such a manner that y satisfies the following formula (4): 51≤y (4)。

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