Seam felt for papermaking

Abstract

To provide a seam felt for paper making allowing a core wire to be easily inserted into loops by engaging the loops with each other.SOLUTION: A seam felt for paper making 1 has a felt body 2 with loops on both ends in a length direction and a pair of temporary connectors 3 used to engage the loops on both ends with each other. The pair of temporary connectors 3 is connected with each other and disposed in a predetermined range of both ends of the felt body 2, and both ends of the felt body 2 are abutted against each other so that abutting part 9 are formed into a mountain shape. As a water soluble resin 4 is applied to the abutting parts 9, the abutting parts are prevented from warping. The water soluble resin 4 is removed by a water circulating operation performed before manufacturing paper.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a papermaking seam felt provided with an auxiliary tool for joining its two ends together. [Background technology]

[0002] Papermaking felt is used in the press section of papermaking machines to transport the wet paper that is being squeezed. To improve the workability when attaching papermaking felt to papermaking machines, so-called seam felt is widely used, in which the felt with ends is pulled into the felt's path, or felt run, and then both ends are joined together to create an endless felt. In this type of seam felt, the loops formed at the ends in the length direction by folding the warp threads that make up the base fabric are interlocked alternately so that the loop holes of each loop are aligned, and the ends are joined by passing a core wire through the common hole formed in this way.

[0003] Joining seam felt in this way is a meticulous manual process, so it is desirable to stabilize the edges of the felt during the work. Also, to make it easier to visually check the interlocking of the loops and the insertion of the core wire, it is desirable to butt the edges of the felt into a V-shape. For this reason, it is known that a temporary fastener equipped with a sliding fastener is sewn onto the edge of the felt in advance, and once the felt has been pulled in, the fastener is closed to temporarily secure both ends of the felt and to hold both ends of the felt in a V-shape (Patent Documents 1-3). Furthermore, Patent Document 4 describes applying liquid resin to the loops to facilitate the core wire removal process. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 62-250294 [Patent Document 2] Japanese Patent Publication No. 2005-264402 [Patent Document 3] Japanese Patent Publication No. 2010-275671 [Patent Document 4] Japanese Patent Publication No. 2010-065343 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] In recent years, the demand for lightweight seam felt has increased due to the requirements of papermaking machines. Lightweight seam felt has reduced rigidity compared to conventional products. In particular, if the bending modulus of elasticity (bending rigidity) in the length direction is low, when the ends of the seam felt are butted together to form a mountain shape, the inclined surface that forms the mountain shape will bend inward, making it difficult to interlock the loops. Also, if the bending modulus of elasticity in the width direction of the seam felt is low, the top of the mountain shape will bend or indent downward during the core wire insertion process, making it difficult to insert the core wire. The process of interlocking the loops and passing the lead wire can be completed in less than 10 minutes per meter with relatively heavy and rigid seam felt, but with relatively light and less rigid seam felt, it can take more than 30 minutes per meter, and in the worst case, the core wire may not be inserted and may have to be detached.

[0006] In view of the above background, the present invention aims to provide a seam felt for papermaking that allows for easy insertion of a core wire into a loop by interlocking the loops, even if the seam felt is lightweight and has low rigidity. [Means for solving the problem]

[0007] To solve the above problems, a papermaking seam felt (1) according to one aspect of the present invention comprises a base fabric (5) and a butt fiber layer (6) integrated with the base fabric, and has a plurality of loops (7) at both ends in the length direction that are to interlock with each other, and a felt body (2) divided into a pair of butt portions (9) defined in a predetermined range from both ends toward the center in the length direction and an intermediate portion (10) defined between the pair of butt portions, and the pair of butt portions and the intermediate portion in the felt body The device comprises a pair of temporary fasteners (3) that are detachably attached to the boundary with the part, are capable of engaging and disengaging with each other, and, when engaged with each other, hold the pair of abutting parts in a state where their ends are abutted together such that they form a mountain shape, wherein at least one of the pair of abutting parts has a water-soluble resin (4) applied to the surface of at least one of the butt fiber layers near the loop, and the length of the applied water-soluble resin in the length direction is at least half the length of the abutting part in the length direction.

[0008] According to this embodiment, the rigidity in the vertical direction of the butt joint is reinforced by the water-soluble resin, so that the warping of the butt joint, which is joined in a mountain shape, is suppressed, and the work of interlocking the loops and inserting the core wire into the loops can be easily performed.

[0009] In the above embodiment, the length in the vertical direction of the water-soluble resin (4) applied to the butt joint (9) may be 3 cm or more and 8 cm or less.

[0010] According to this embodiment, the size of the area where the water-soluble resin (4) is applied is such that the loop interlocking work can be easily performed, and the bending moment in the length direction applied to the butt joint during the loop interlocking work and core wire insertion work is not excessive, and warping can be suppressed by reinforcement with the water-soluble resin.

[0011] In the above embodiment, the butt joint portion before the application of the water-soluble resin may have a flexural modulus of 7.0 MPa or less in the length direction.

[0012] According to this aspect, the bending rigidity does not become excessive enough to inhibit workability.

[0013] In the above aspect, the water-soluble resin may include polyvinyl alcohol, carboxymethyl cellulose, polyvinyl acetate or modified starch, or a combination thereof.

[0014] According to this aspect, the rigidity reinforcement effect by the water-soluble resin and the removability of the water-soluble resin by the water circulation operation are good.

[0015] In the above aspect, the water-soluble resin (4) includes polyvinyl alcohol, and the water-soluble resin applied to the butted portion (9) has a basis weight of 20 g / m 2 or more and 40 g / m 2 or less.

[0016] According to this aspect, the rigidity reinforcement effect by the water-soluble resin and the removability of the water-soluble resin by the water circulation operation are further improved.

Effect of the Invention

[0017] According to the above aspects, it is possible to provide a papermaking seam felt that can easily perform the operation of engaging loops and inserting a core wire into a loop hole even with a lightweight and low-rigidity seam felt.

Brief Description of the Drawings

[0018] [Figure 1] Perspective view showing a papermaking seam felt according to an embodiment [Figure 2] Perspective view showing the felt body of a papermaking seam felt according to an embodiment [Figure 3] Vertical cross-sectional view showing the periphery of the joint of a papermaking seam felt according to an embodiment [Figure 4] Plan view showing the periphery of the joint of a papermaking seam felt according to an embodiment [Figure 5]Plan view showing the area around the joint of a papermaking seam felt according to a modified embodiment. [Figure 6] Front view showing a test apparatus for measuring physical properties related to the flexural modulus. [Modes for carrying out the invention]

[0019] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a perspective view showing the joint of a papermaking seam felt 1 according to an embodiment. In the following description, the term "length direction" refers to the length direction (warp direction) of the papermaking seam felt 1, and the term "width direction" refers to the width direction (weft direction) of the papermaking seam felt 1.

[0020] As shown in Figure 1, the papermaking seam felt 1 comprises a felt body 2 that is attached to a papermaking machine (not shown), such as a paper machine or pulp machine, to transport wet paper that has been dewatered, and a pair of temporary fasteners 3 used to join both ends of the felt body 2 in the length direction, and which are removed after the ends have been joined. A water-soluble resin 4 is applied near the ends of the felt body 2.

[0021] Figure 2 is a perspective view of the felt body 2. As shown in Figure 2, the felt body 2 includes a base fabric 5 and a butt fiber layer 6 formed by needling a short fiber sheet of synthetic resin such as polyamide, polyester, polyethylene, polypropylene, or polyvinyl chloride into the base fabric 5. Multiple loops 7 are formed at both ends of the base fabric 5 in the length direction. The felt body 2 is used in the press part of a papermaking machine. The loops 7 at both ends are interlocked, and the core wire 8 (see Figure 3) is inserted through the holes defined by the loops 7 to join the ends, creating an endless structure. Its inner (running surface side) surface is supported by a roll (not shown) of the papermaking machine, and its outer (papermaking surface side) surface supports the wet paper. Each loop 7 is formed by folding back the warp threads in the base fabric 5. The loops 7 protrude from the butt fiber layer 6. In the following description, the "base end" of the loop 7 means the part of the loop 7 that begins to protrude from the butt fiber layer 6.

[0022] Figure 3 is a longitudinal cross-sectional view of the area around the joint of the papermaking seam felt 1. As shown in Figures 1 and 3, the felt body 2 is divided in the length direction into a pair of butt joints 9 defined within a predetermined range from both ends toward the center in the length direction, and an intermediate section 10 defined between the pair of butt joints 9. The lengths of the pair of butt joints 9 in the length direction may be equal to each other or may be different.

[0023] Each pair of temporary fasteners 3 includes a fabric portion 11 fixed to the surface of the felt body 2, and a fastener element portion 12 attached to one end edge of the fabric portion 11. A slider 13 is slidably attached to either of the pair of fastener element portions 12 for interlocking and disengaging the fastener elements 12. In other words, the pair of temporary fasteners 3 are joined together by a wire fastener (sliding fastener).

[0024] Each pair of temporary fasteners 3 is sewn to the felt body 2 with thread 14 near the edge of the fabric portion 11 opposite to the edge to which the fastener element portion 12 is attached, so that the fastener element portions 12 of each pair can face each other. The fastener element portions 12 extend parallel to the width direction. The sewing line of the thread 14 that sews the fabric portion 11 to the felt body 2 extends in the width direction and forms the boundary between the butt joint portion 9 and the intermediate portion 10 of the felt body 2. The distance from this sewing line to the fastener element portion 12 is shorter than the distance from this sewing line to the loop 7. Therefore, when the fastener element portions 12 of the pair of temporary fasteners 3 are engaged with each other and the ends of the felt body 2 in the length direction are butted together, the butt joint portion 9 forms a mountain shape with the butted ends as its apex. The sewing method of the thread 14 that sews the temporary fasteners 3 to the felt body 2 is preferably a double chain stitch using a sewing machine.

[0025] At each of the ends of the felt body 2 in the length direction, the distance from the tip of the loop 7 to the thread 14 that sews the temporary fastener 3 to the felt body 2, that is, the length of the butt joint 9 in the length direction, is preferably 4 cm or more and 10 cm or less, and more preferably 6 cm or more and 8 cm or less. This embodiment is preferably applied to a papermaking seam felt 1 having a butt joint 9 having a bending modulus of elasticity in the length direction of 7.0 MPa or less, preferably 5.0 MPa or less, and even more preferably 3.0 MPa or less, before applying the water-soluble resin 4.

[0026] Figure 4 is a plan view of the area around the joint of the papermaking seam felt 1. As shown in Figure 4, a water-soluble resin 4 is applied to the surface of the butt fiber layer 6 at the butt joint 9. In the illustrated example, the water-soluble resin 4 is applied to the surface of the felt body 2 opposite to the side to which the temporary fastener 3 (see Figure 3) is attached. However, it may also be applied to the surface on the same side as the temporary fastener 3 attached to the felt body 2, or to both surfaces. It is preferable that the water-soluble resin 4 is applied over the entire width. It is preferable that the water-soluble resin 4 has a length in the height direction of the butt joint 9 that is at least half the height direction of the butt joint 9, and it is preferable that the edge of the water-soluble resin 4 on the loop 7 side is positioned to substantially overlap the height direction edge of the butt fiber layer 6, or the base end of the loop 7 in a plan view. Note that the application range of the water-soluble resin 4 described here is at the time of application, and the applied water-soluble resin 4 may seep into the surrounding area by capillary action, etc., before it dries. As the water-soluble resin 4, for example, polyvinyl alcohol (PVA), carboxymethylcellulose (CMC), polyvinyl acetate (PVAc), modified starch, or a combination thereof can be used, but other resins that can exhibit similar functions and effects can also be used. The surface density of the water-soluble resin 4 is 20 g / m². 2 More than 40g / m 2 It is more preferable that the following is the case: 30 g / m 2 More than 40g / m 2 The following is even more preferable:

[0027] Figure 5 is a plan view of the area around the joint in a modified example of the seam felt 1 for papermaking. As shown in Figure 5, the edge of the water-soluble resin 4 on the loop 7 side is located at a position that substantially overlaps with the edge of the butt fiber layer 6 in the length direction, or with the base end of the loop 7 in a plan view, and the edge of the water-soluble resin 4 on the intermediate portion 10 side may be located at or near the boundary between the butt joint 9 and the intermediate portion 10. If the water-soluble resin 4 is applied across the boundary between the butt joint 9 and the intermediate portion 10, it becomes difficult to sew the temporary fastener 3 to the felt body 2, so it is preferable that the water-soluble resin 4 be applied to the butt joint 9 so as not to cross this boundary.

[0028] Referring to Figures 1 and 3, the method for joining the ends of the papermaking seam felt 1 in the length direction will be described.

[0029] At the manufacturing plant for papermaking seam felt 1, after the felt body 2 is manufactured, a water-soluble resin 4 is applied to the butt joint 9, and a pair of temporary fasteners 3 are sewn onto the felt body 2. The papermaking seam felt 1 is shipped from the manufacturing plant and transported to the paper mill. Workers perform the following tasks at the paper mill.

[0030] First, the papermaking seam felt 1 is drawn into the travel path of the papermaking machine, and both ends of the felt body 2 are brought close together and facing each other.

[0031] Next, the slider 13 of the pair of temporary fasteners 3 is slid along the pair of zipper element parts 12 to interlock the zipper element parts 12 with each other. Since the pair of temporary fasteners 3 are attached near both ends of the felt body 2, the ends of the felt body 2 can be held together. At this time, the distance from the sewing line of the thread 14 that sews the pair of temporary fasteners 3 to the felt body 2 to the zipper element part 12 is shorter than the distance from this sewing line to the loop 7, so the butt joint 9 forms a mountain shape that protrudes on the opposite side from the temporary fastener 3.

[0032] Next, starting from one end in the width direction and moving towards the other end, the lead wire (not shown) connected to the core wire 8 is passed through the holes in the loops 7, aligning the holes in the loops 7 in the width direction so that the loops 7 at both ends in the height direction are alternately arranged. Once the lead wire reaches the other end in the width direction, the lead wire is pulled to pass the core wire 8 through the hole in the loop 7.

[0033] Next, slide the slider 13 in the opposite direction to release the interlocking of the zipper element 12. Then, untie the thread 14 and remove the temporary fastener 3 from the felt body 2.

[0034] Water is introduced into the papermaking machine instead of paper raw materials, and a water circulation operation is performed to operate the papermaking machine and remove the water-soluble resin 4 from the felt body 2.

[0035] The effects and advantages of the above embodiment will now be explained.

[0036] The water-soluble resin 4 reinforces the bending modulus in the length direction of the portion of the felt body 2 near the loop 7, thereby suppressing the curvature of the butt joint 9 which is joined in a mountain shape. This makes it easier to pass the lead wire and core wire 8 through the hole in the loop 7, and shortens the working time.

[0037] Furthermore, the water-soluble resin 4 reinforces the flexural modulus in the width direction of the portion of the felt body 2 near the loops 7. This prevents the rows of loops 7 from sagging or bending downwards when inserting the lead wires into the holes of the loops 7, making it easier to pass the lead wires and core wires 8 through the holes of the loops 7 and shortening the working time.

[0038] Since the water-soluble resin 4 is removed by the water circulation operation, it does not adversely affect the performance of the papermaking machine. Furthermore, since the water circulation operation is performed to allow the felt body 2 to become familiar with the papermaking machine regardless of the presence or absence of the water-soluble resin 4, no additional work is required to remove the water-soluble resin 4.

[0039] The surface density of water-soluble resin 4 is 20 g / m².2 If it is less than this value, the rigidity of the butting portion 9 is not sufficiently reinforced, and the areal density of the water-soluble resin 4 is 40 g / m 2 If it is greater than this value, the rigidity of the butting portion 9 is sufficiently reinforced, but it is necessary to lengthen the flushing operation time for removing the water-soluble resin 4. The areal density of the water-soluble resin 4 is 20 g / m 2 or more and 40 g / m 2 or less. Therefore, it is possible to achieve both reinforcement of rigidity and removal efficiency of the water-soluble resin 4.

[0040] If the areal density of the water-soluble resin 4 is too large, the rigidity of the butting portion 9 becomes too high, and when the loops 7 at both ends in the length direction are engaged with each other, it becomes difficult to finely adjust the position of the loop 7 such as bending the wire. The areal density of the water-soluble resin 4 is 20 g / m 2 or more and 40 g / m 2 or less. Therefore, it is possible to achieve both workability of inserting the core wire and removal efficiency of the water-soluble resin 4.

[0041] Since the length of the water-soluble resin 4 in the length direction is 3 cm or more and 8 cm or less, it is easy to engage the loops 7. Also, if the coating range of the water-soluble resin 4 is of this size, the bending moment in the length direction applied to the butting portion 9 during the loop engagement operation and the core wire insertion operation does not become excessive. Therefore, even for the water-soluble resin 4 with a smaller rigidity reinforcement effect compared to the case of attaching a plate-shaped rigidity reinforcing member (not shown), warping of the butting portion 9 can be suppressed.

Example

[0042] The flexural modulus in the vertical direction was measured for two test pieces 15 before the application of the water-soluble resin. Figure 6 shows the test apparatus 16 used to measure the flexural modulus (testing machine: Strograph Model E3-L (Toyo Seiki Seisakusho), jig: 3-point bending jig Model F-0 (Toyo Seiki Seisakusho)). The test apparatus 16 comprises a pair of support bases 17 with a support base radius of 5 mm (the roundness of the opposing ends of the surfaces supporting the test piece 15) and arranged so that the distance between the support points is 40 mm, and an indenter 18 with an indenter radius of 5 mm. The bending speed was 5 mm / min, the test piece size was 100 mm × 25 mm, and the number of tests was 3 for each test. The test pieces 15 were left in a constant temperature and humidity chamber at room temperature of 19.5°C and humidity of 65% for 24 hours or more so that the papermaking side was indented, and then the flexural modulus was measured. Furthermore, for each test piece 15, the ends in the length direction were butted together so that the butt joint 9, which has a length of 8 cm in the length direction, forms a mountain shape, and the loops 7 at both ends in the length direction were interlocked and the core wire 8 was inserted. The results are shown in Table 1.

[0043] [Table 1]

[0044] The second test specimen, which had a relatively high flexural modulus, allowed for both interlocking and core wire insertion without any problems. The first test specimen, which had a relatively low flexural modulus, was difficult to work with in both interlocking and core wire insertion, and took longer to complete compared to the second test specimen.

[0045] For the first test piece, which was difficult to assemble and insert the core wires into as is, a water-soluble resin 4 made of polyvinyl alcohol resin was added at concentrations of 5, 10, 20, 30, 40, 50, and 60 g / m². 2 The resin was applied at a surface density, and interlocking and core wire insertion were performed. The length of the butt joint 9 in the vertical direction was 8 cm, and the length of the water-soluble resin 4 in the vertical direction was 5 cm from the base end of the loop 7. The water-soluble resin 4 was applied using a spray gun. The results are shown in Table 2.

[0046] [Table 2]

[0047] The coating amount of water-soluble resin 4 is 10 g / m². 2 If the amount was less than 10g / m², it did not provide enough rigidity, making it difficult to interlock loop 7 and insert the core wires. 2 With the above specifications, the interlocking workability of loop 7 is improved, especially for 20-40 g / m 2 With this setup, both the interlocking of loop 7 and the insertion of the core wire were easy and could be performed without any problems. 50g / m 2 and 60g / m 2 Regarding the amount of water-soluble resin 4 applied, the interlocking workability of the loop 7 improved, but the core wire insertion work became somewhat difficult. This is because the large amount of resin causes some of the resin to penetrate into the loop 7, creating resistance and hindering the insertion of the core wire.

[0048] For the first test specimen with a length of 6 cm in the vertical direction, water-soluble resin 4 made of polyvinyl alcohol resin was applied at lengths of 2, 3, 4, and 6 cm in the vertical direction (length from the base end of loop 7), and interlocking and core wire insertion work was performed. Similarly, for the first test specimen with a length of 8 cm in the vertical direction, water-soluble resin 4 made of polyvinyl alcohol resin was applied at lengths of 2, 3, 4, 6, and 8 cm in the vertical direction (length from the base end of loop 7), and interlocking and core wire insertion work was performed. The surface density of the applied water-soluble resin 4 was 40 g / m². 2 The results are shown in Table 3.

[0049] [Table 3]

[0050] If the length of the water-soluble resin 4 in the vertical direction was less than half the length of the butt joint 9 in the vertical direction, the warping of the parts not coated with the water-soluble resin 4 was significant, making it difficult to interlock the loops 7 and insert the core wires. If the length of the water-soluble resin 4 in the vertical direction was half or more the length of the butt joint 9 in the vertical direction, the warping of the parts not coated with the water-soluble resin 4 had little effect, making it easier to interlock the loops 7 and insert the core wires.

[0051] This concludes the description of specific embodiments, but the present invention is not limited to the above embodiments or modifications and can be broadly modified and implemented. A pair of temporary fasteners may be temporarily joined by a point fastener with multiple snap buttons instead of a wire fastener, or by a hook-and-loop fastener, or by having multiple holes in each of the temporary fastener bodies and being temporarily joined by a string or the like inserted through these holes. Instead of sewing the pair of temporary fasteners together after applying the water-soluble resin, the water-soluble resin may be applied after sewing the pair of temporary fasteners together. [Explanation of Symbols]

[0052] 1: Seam felt for papermaking 2: Felt body 3: Temporary fasteners 4: Water-soluble resin 6: Butt fiber layer 7: Loop 8: Core wire 9: Butt joint 10: Middle section

Claims

1. A felt body comprising a base fabric and a butt fiber layer integrated with the base fabric, wherein a plurality of loops are provided at both ends in the length direction to interlock with each other, and the felt body is divided into a pair of butt joints defined in a predetermined range from both ends toward the center in the length direction, and an intermediate part defined between the pair of butt joints, A pair of temporary fasteners are detachably attached to the boundary between a pair of abutting portions and the intermediate portion of the felt body, and are capable of engaging and disengaging with each other, and when engaged, hold the pair of abutting portions in a state where their ends are abutted together so that they form a mountain shape. Equipped with, At least one of the pair of abutting portions has a water-soluble resin applied to the surface of at least one of the butt fiber layers near the loop. A seam felt for papermaking, wherein the length of the coated water-soluble resin in the vertical direction is 1 / 2 or more of the length of the butt joint in the vertical direction.

2. The papermaking seam felt according to claim 1, wherein the length in the vertical direction of the water-soluble resin applied to the butt joint is 3 cm or more and 8 cm or less.

3. The seam felt for papermaking according to claim 1, wherein the butt joint portion before the application of the water-soluble resin has a flexural modulus of 7.0 MPa or less in the length direction.

4. The water-soluble resin comprises polyvinyl alcohol, carboxymethylcellulose, polyvinyl acetate, or modified starch, or a combination thereof, as described in any one of claims 1 to 3, for use as a papermaking seam felt.

5. The aforementioned water-soluble resin contains polyvinyl alcohol, The water-soluble resin applied to the butt joint portion is 20 g / m². ２ More than 40g / m ２ The papermaking seam felt according to claim 4, having the following surface density.

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