JP2010031397A - Roll for papermaking - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roll for papermaking, which especially improves releasability of wet paper from a roll for papermaking in a roll for papermaking in a paper machine. <P>SOLUTION: In the roll for papermaking, which is mounted on a paper machine having a paper stock feed part, a dehydration part, a press part and a drying part and is brought into contact with wet paper having a water content of 30-95%, grooves are formed on the surface of the roll for papermaking and have a contact area ratio between the wet paper and the roll for papermaking of 60-99% per the prescribed area. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a papermaking roll in a papermaking machine, and more particularly to a papermaking roll for improving the peelability between a papermaking roll and a wet paper.

  In a paper machine, wet paper is formed from raw materials including water and fibers, and the formed wet paper is dehydrated while being pressed by a press part, and dried to obtain a dry paper product. At this time, in the press part, for example, in order to form a paper layer of a multi-layer paper, the moisture of the paper layer is removed by a papermaking press roll, but depending on the material of the papermaking press roll, surface properties, press conditions, etc., It has a great influence on the texture and texture of paper. Accordingly, the dewatering accuracy in the press part is a very important process in the production of paper (product), and there are many problems regarding the papermaking press roll used in the press part.

  The papermaking press roll is a pair of a papermaking top press roll and a papermaking bottom press roll. Usually, the paper machine has a plurality of paper press parts, and the water in the paper layer is gradually dehydrated every time it passes through the press part. In addition, as a dewatering method for the press part, a wet paper made of a raw material and containing a large amount of moisture is passed between a pair of papermaking press rolls pressed in a state of being held on the felt, and the moisture of the wet paper is A typical method is to shift the belt to the felt side.

  According to this configuration, since one side (lower surface) of the wet paper is held by the felt, it is not in contact with the bottom press roll for papermaking through the felt, but the other side (upper surface) of the wet paper is the top for papermaking. It will be in direct contact with the press roll.

  Also, when sending wet paper from the press roll to the press roll or the next process, the wet paper is peeled off from the felt and the wet paper is transferred directly to the roll of the next process. It is necessary to peel off at a predetermined position. Therefore, in order to improve the peelability between the wet paper and the papermaking press roll, a natural granite roll has been used as the papermaking top press roll. In addition, a resin-made or rubber-made roll that is softer than the paper-making top roll has been used for the paper-making bottom press roll.

  However, when there are concerns about roll breakage due to higher speeds and higher temperatures of paper machines, the use of granite, which is a natural resource, will lead to resource depletion, making it difficult to obtain granite itself in a few years. It is expected to be.

  Therefore, in order to maintain the peelability of wet paper and papermaking press rolls, synthetic stones made by mixing hard resin or hard rubber with granule or granite particles are proposed as substitutes for natural granite. (For example, see Patent Document 1).

  However, in the press part of a paper machine, the peelability between the wet paper and the papermaking press roll is not sufficient, and the current situation is that the peelability is still a problem. As shown in FIG. 17, the peelability failure means that the wet paper (4) pressurized to the press top roll (1) and the press bottom roll (3) passes the press point top roll. Peel from (1) (27) Hold on the felt (5) and proceed to the next step, but do not peel even after the point to be peeled off (26), adhere to the surface of the press top roll (1) It is a phenomenon that rotates while being attracted. Such a peelability defect has been a problem with rolls through which wet paper containing water of 40% or more passes on the paper machine other than the papermaking press roll used in the press part.

  Further, as one means for improving the peelability failure, a roll having a ceramic film formed on the surface of the roll has been proposed. This forms an undercoating layer made of, for example, an alloy of 95% Ni-5% Al on the surface of a roll shell made of cast steel constituting the press roll body for papermaking. A press roll for papermaking in which a ceramic powder formed by adding 13% or more of TiO2 (titanium dioxide) to Al2O3 (alumina) or a ceramic powder containing TiO2 as 100% to form a ceramic sprayed coating ( For example, see Patent Document 2).

  Furthermore, as another means for improving the peelability failure, a paper making method has been proposed in which a chemical solution is always applied to a paper making press roll. This is because a constant amount of wax as a peeling improver is continuously supplied to the surface of a rotating papermaking press roll, so that the wax is uniformly distributed over the surface of the papermaking press roll to form a wax film. (For example, refer to Patent Document 3).

JP 50-090704 A Japanese Patent Laid-Open No. 10-219581 JP 2000-345489 A

  However, the synthetic stone proposed in Japanese Patent Application Laid-Open No. 50-090704 is inferior in the smoothness and water retention of the press roll surface for papermaking. Therefore, in wet paper containing a lot of water, the wet paper is used for papermaking. It becomes difficult to peel off from the press roll, resulting in defects such as running out of paper.

  Also, the papermaking press roll formed with the ceramic film proposed in Japanese Patent Laid-Open No. 10-219581 is not sufficient although the peelability of the wet paper and the papermaking press roll is improved. Furthermore, since a separate process for forming a ceramic coating on the surface by a thermal spraying method or the like is required, the price is higher than the manufacturing cost of a papermaking press roll, and the manufacturing cost is particularly high for products manufactured in small lots. There is concern.

  Further, the chemical solution applying means proposed in Japanese Patent Application Laid-Open No. 2000-345489 requires a fine adjustment to the application amount of the chemical solution because the application amount of the chemical solution greatly affects the peelability, and the application amount is too small. If the peelable effect is reduced and the coating amount is too large, there is a concern about the influence on the wet paper. In addition, felt stains easily occur due to chemicals, which may cause a reduction in dehydration power.

  In addition, when manufacturing paper of different types such as two-layer paper or three-layer paper on a long paper machine, if the wet paper does not peel from the paper roll and causes poor peelability, the upper layer paper Only the film is attracted and rotated while adhering to the surface of the paper roll, and delamination occurs between the paper layers in the multilayer paper.

  In addition, in the paper machine, in addition to the papermaking press roll used in the press part, a roll is used in a portion where a wet paper having a moisture content of 30% to 95% passes. The roll peelability was poor.

  The present invention is intended to solve the above-mentioned problems, forming grooves on the surface of the papermaking roll, improving the water retention of the surface of the papermaking roll, and contacting the surface of the papermaking roll with the wet paper By reducing the area, a papermaking roll having good wet paper peelability due to their synergistic effect is provided.

  The papermaking roll of the present invention is installed in a papermaking machine having a paper supply unit, a dewatering unit, a pressing unit, and a drying unit, and is used for papermaking in a papermaking roll in contact with a wet paper having a moisture content of 30 to 95%. Grooves are formed on the surface of the roll, and the grooves are provided so that the contact area ratio between the wet paper and the papermaking roll is in the range of 60% to 99% per predetermined area.

  The predetermined area is about 10% of the total area in the effective surface length of the papermaking roll.

  The groove of the papermaking roll in the present invention is characterized in that the pitch is 1.0 mm to 10.0 mm and the depth is 0.03 mm to 0.3 mm.

  By forming a predetermined groove on the surface of the papermaking roll, it becomes possible to obtain higher water retention on the roll surface than before. Furthermore, the contact area between the surface of the papermaking roll and the wet paper can be reduced by adjusting the contact area between the surface of the papermaking roll and the wet paper. By these synergistic effects, a high peeling effect between the wet paper and the papermaking roll can be obtained. Moreover, in multilayer paper, delamination does not occur between paper layers.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a front view of a papermaking roll in the present invention. Also, the inside of the two-dot dashed circle is an enlarged view showing the groove pitch, the groove depth, the groove width, and the contact length between the wet paper and the papermaking roll. FIG. 2 shows an example of the shape of the groove of the papermaking roll in the present invention. FIG. 3A shows a case where the grooves of the papermaking roll in the present invention have the same pitch, and FIG. 3B shows a case where the grooves of the papermaking roll have different pitches. FIG. 4 shows the contact area between the pitches of the grooves of the papermaking roll, the number of contacts within the effective surface length of the papermaking roll, and the total contact area of the wet paper and the papermaking roll. FIG. 5 shows a side view of the papermaking roll in the present invention. FIG. 6 shows the contact area ratio per predetermined area between the papermaking roll and the wet paper in the present invention. 7 shows an example of the shape of the groove when the surface of the papermaking roll in the present invention is viewed from the top. FIG. 8 shows the overall configuration of a single-layer paper manufacturing apparatus according to the present invention. FIG. 9 shows the overall configuration of the multilayer paper manufacturing apparatus in the present invention. FIG. 10 shows a method for calculating the groove width and the groove length when the grooves of the papermaking roll according to the present invention are formed in a triangular shape with a processing bite of 60 degrees. FIG. 11 shows a method for calculating the groove width and the groove length when the grooves of the papermaking roll according to the present invention are formed in a triangular shape with a processing bite of 60 degrees. FIG. 12 shows a method for calculating the groove width and the groove length when the grooves of the papermaking roll in the present invention are formed in a triangular shape with a processing bite of 90 degrees. FIG. 13 shows a calculation method of the groove width and the groove length when the grooves of the papermaking roll in the present invention are formed in a triangular shape with a processing bite of 90 degrees and the groove pitches are varied. FIG. 14 shows a method of calculating the groove width and the groove length when the paper-making roll groove in the present invention is formed in a square shape. FIG. 15 shows a calculation method of the groove width and the groove length when the paper-making roll groove in the present invention is formed in a circular shape. FIG. 16 shows the holding angle between the papermaking roll and the wet paper in the present invention.

  As shown in FIG. 1, a predetermined groove is formed in the papermaking roll in the present invention.

  The surface of the papermaking roll is made of natural stone, resin, or rubber, and the surface hardness ranges from A70 to A100. When the surface hardness is smaller than A70, it is difficult to form a good processed groove, which causes problems such as the occurrence of burrs on the roll surface and poor paper formation.

  As a means for forming a groove in the papermaking roll, it is possible to provide the groove of the papermaking roll in the present invention as long as it is a commercially available processing bite, and the shape and the bite angle are not limited.

  The shape of the groove differs depending on the machining tool to be used. For example, as shown in FIGS. 2 (a) to 2 (c), the shape of the groove having a triangular shape (a), a square shape (b), or a circular shape (c) may be used. Can be mentioned. However, if other machining tools are used, other groove shapes can be formed.

  The conditions for the grooves formed in the papermaking roll used when the wet paper moisture content is 50% to 70% are shown below. The range of the pitch of the grooves is 1.0 mm to 10.0 mm. In the present invention, the pitch of grooves refers to the length from the point that becomes the low point of one groove to the point that becomes the low point of adjacent grooves. In the case of the triangular groove shown in FIG. 2 (a), the convex portion (mountain portion) which is the deepest part of the groove with respect to the surface of the paper roll is a low point, and the rectangular groove shown in FIG. In the case of the groove, the center of the bottom portion of the groove is a low point, and in the case of the circular groove shown in FIG. 2C, the curved portion that is the deepest portion of the groove with respect to the surface of the papermaking roll is low. It becomes a point.

  When the pitch of the grooves is smaller than 1.0 mm and the processing depth is increased, adjacent grooves are too close to each other, causing a problem that burrs are generated on the surface of the roll due to a defective shape of the convex portion (mountain portion). . In addition, when it is larger than 10.0 mm, it is difficult to obtain the effect of improving the water retention of the roll surface, and the contact area between the wet paper and the papermaking roll cannot be reduced so much. The problem of lowering occurs.

  The pitch of the grooves formed on the papermaking roll may be formed at a constant pitch as shown in FIG. 3 (a) or an irregular pitch as shown in FIG. 3 (b). The groove pitch may be in the range of 1.0 mm to 10.0 mm. Hereinafter, an embodiment in which the groove pitch is constant will be described.

  The range of the depth of the groove is 0.03 mm to 0.3 mm. The depth of the groove in the present invention means a length obtained by connecting the surface of the papermaking roll to the low point of the groove at a right angle. When the depth of the groove is smaller than 0.03 mm, there arises a problem that it is difficult to obtain the effect of improving the water retention of the roll surface. Further, when the depth of the groove is larger than 0.3 mm, the water retention becomes too high, resulting in a problem of poor paper texture.

  The depth of the groove formed in the papermaking roll may be different between adjacent grooves, but in that case, after forming one line of groove, the angle of the machining bite is changed when forming the adjacent groove. It is necessary to change, which is not preferable in practice.

  Further, the width and contact length of the groove are calculated by the depth of the groove. The width of the groove in the present invention refers to the width of the opening of the groove engraved with a cutting tool. Further, the contact length in the present invention refers to a dimension in which a non-processed portion between grooves engraved with a cutting tool comes into contact with wet paper or paper.

  The width of the groove depends on the depth of the groove and the shape of the machining tool. For example, when the shape of the machining tool is a triangle, it is calculated by the length ratio of the triangular shape of the cross section of the groove and the depth of the groove according to the machining tool angle. Further, when the angle of the machining tool is a square shape, it is calculated from the length of the cutting edge of the machining tool and the depth of the groove. Further, when the shape of the machining tool is circular, a groove is formed by laser engraving, and therefore depends on the laser to be used. Further, the contact length is calculated by (groove pitch-groove width).

  A method for calculating the total contact area between the wet paper and the papermaking roll will be described.

  First, the contact area between the pitches of the grooves is calculated. The contact area between the pitches of the grooves in the present invention refers to the area where the roll is in contact between the pitches of the grooves as shown in FIG. The contact area between the pitches of the grooves is calculated by (contact length × nip width). As shown in FIG. 5, the nip width is the width in the wet paper flow direction where the wet paper and the paper making roll come into contact when the paper making roll is pressed against the wet paper.

  Next, the number of contacts within the effective surface length of the papermaking roll is calculated. The number of contacts within the effective surface length of the papermaking roll in the present invention refers to the number of contact portions in the length in the paper width direction where the wet paper and the papermaking roll contact. The number of contacts within the effective surface length of the papermaking roll is calculated by (effective surface length of papermaking roll / groove pitch).

  Based on the above results, the total contact area between the wet paper and the papermaking roll is calculated. The total contact area between the wet paper and the papermaking roll in the present invention refers to the total area obtained by multiplying the number of contact lengths (unprocessed portions) within the effective area of the roll by the contact area. The total contact area between the wet paper and the papermaking roll is calculated by (contact area between pitches of grooves × number of contacts within the effective surface length of the papermaking roll).

  The nip width depends on the surface hardness of the papermaking roll, the diameter of the papermaking roll, and the like. However, it is 1.0 mm to 10.0 mm on the execution surface.

  Considering the peelability of the wet paper and the papermaking roll accompanying the water retention of the papermaking roll surface, the range of the contact area ratio between the wet paper and the papermaking roll is 60% to 99% per predetermined area. When the contact area ratio between the wet paper and the papermaking roll is less than 60%, the water retention on the surface of the papermaking roll becomes too high, resulting in a problem of poor paper texture. Conversely, if the contact area ratio between the wet paper and the papermaking roll is greater than 99%, the water retention on the surface of the papermaking roll is lowered, and the peeling effect between the wet paper and the papermaking roll is reduced.

  However, the above-mentioned predetermined per predetermined area is about 10% in a continuous region with respect to the total area of the effective surface length of the papermaking roll, as shown in FIG.

  As a reason for about 10% in the continuous area, as shown in FIG. 6B, for example, in the area where the X area, the Y area, and the Z area, which are non-continuous areas, total 10%. Even if it is a papermaking roll in which the contact area ratio between the paper and the papermaking roll is 80%, the problem of the present invention has not been solved, and in order to make a papermaking roll for solving the problem, This is because it is necessary to provide grooves almost evenly.

  In addition, as shown in FIG. 6C, for example, in the case of making a paper roll having grooves in which the contact area ratio between the wet paper and the paper roll is 80%, the effective surface length of the paper roll is Even if it is a papermaking roll in which the contact area ratio between the wet paper and the papermaking roll is 80% by providing grooves intensively on the other side without providing any groove on one side This is because the problem of the present invention cannot be solved, and in order to obtain a papermaking roll for solving the problem, it is necessary to provide grooves almost evenly.

  From this, the contact area ratio of the wet paper and the papermaking roll needs to be 60% to 99% per 10% continuous area at any location with respect to the total area of the effective surface length of the papermaking roll. There is.

  When the surface of the papermaking roll is viewed from the top, the groove formed on the papermaking roll may be a continuous groove as shown in FIG. 7A, or a discontinuous groove as shown in FIG. 7B. But it ’s okay. Furthermore, in the drawings, the groove and the adjacent groove are in a parallel state without overlapping, but are not limited to this, and may be in a lattice state.

  Next, a paper making method in the case of a single layer will be described. FIG. 8 shows the overall configuration of a single-layer paper manufacturing apparatus.

  The apparatus for producing single-layer paper is referred to as a long net paper machine (28), and has a wire (9) for making endless paper which is made of a net band and circulates. The wire (9) is bridged between the suction couch roll (10) and the breast roll (11), and is supported and guided by a plurality of rolls (not shown) arranged inside along the wire (9). Cycle around.

  A paper supply tank (12) is disposed from the upstream side to the downstream side in the upstream portion (movement start end portion on the upper surface of the wire) of the wire (9).

  The stock supply tank (12) is filled with the stock (15), and is appropriately replenished from a supply source (not shown) and controlled to maintain a predetermined liquid level. The paper stock (15) is mainly composed of pulp fiber, water, chemicals and filler.

  In the downstream portion of the stock supply tank (12), stock stop plates (17a, 17b, 17c) are arranged. The supplied stock (15) flows into the gap between the stock plugs (17a, 17b, 17c) and the wire (9), and the stock mat (8) is placed on the wire (9). Form and enable papermaking.

  A suction box (22) is disposed below the wire (9) at the downstream side (moving terminal portion on the upper surface of the wire). The suction box (22) is for dewatering by forcibly sucking water contained in the paper mat (8) in the downstream portion of the wire (9) in the paper making process.

  The single-layer paper in the wet paper state formed by the wire (9) is guided by a guide roll (not shown) and wound by a winding roll as a final product, but between the wire (9) and the winding roll, it is upstream. From the side, a press part top roll (1), a press part bottom roll (3), a paper roll (29, 30, 31) and a drying device (25) are disposed.

  The press part top roll (1) and the press part bottom roll (3) sandwich the single-layer paper and further feed it to the downstream take-up roll (25). The drying device (23) uses a known drying device.

  Next, a paper making method in the case of multiple layers will be described. FIG. 9 shows the overall configuration of a multilayer paper manufacturing apparatus.

  The apparatus for producing multi-layer paper is called a long-mesh paper machine (28), and has an endless paper-making wire (9) made of a web band and circulated. The wire (9) is bridged between the suction couch roll (10) and the breast roll (11), and is supported and guided by a plurality of rolls (not shown) arranged inside along the wire (9). Cycle around.

  From the upstream side to the downstream side, the lower layer paper supply tank (12), the intermediate sheet supply device (13), and the upper layer paper supply tank are arranged at the upstream part (movement start end part on the upper surface of the wire) of the wire (9) (14) are sequentially arranged at intervals.

  The lower layer stock supply tank (12) and the upper layer stock supply tank (14) are respectively filled with the lower layer stock (15) and the upper layer stock (16), and are appropriately replenished from a supply source (not shown). The liquid level is controlled to be maintained. The lower layer stock (15) and the upper layer stock (16) are materials that are used as the material of the lower layer stock layer (8) and the upper layer stock layer (6), and mainly include pulp fibers, water, and additives.

  In the downstream portion of each of the lower layer material supply tank (12) and the upper layer material supply tank (14), a lower sheet material sealing plate (17) and an upper layer material sealing plate (18) are respectively arranged. Has been. The lower layer stock (15) and the upper layer are respectively placed on the wire (9) through a gap between the lower layer stock plate (17) and the upper layer stock plate (18) and the wire (9). Paper stock (16) is supplied to enable papermaking.

  The intermediate sheet supply portion by the intermediate sheet supply device (13) is provided on the downstream side of the lower layer material supply tank (12) and upstream of the upper layer material supply tank (14). The intermediate sheet (7) is supplied on the lower layer paper layer (wet paper) (8) formed on the sheet. The intermediate sheet supply device (13) includes a sheet roll (19), a feeding roll (20), and a dancer roll (21).

  The width of the belt-shaped intermediate sheet supplied from the intermediate sheet supply device (13) is the lower layer stock formed by being supplied to the upper surface (conveying surface) of the wire (9) from the lower material sealing plate (17). The upper layer paper layer (8) is substantially the same as the width of the layer (lower wet paper) (8), and is further supplied to the upper surface of the lower layer paper layer (8) from the upper sheet material sealing plate (18). The width of the upper wet paper (6) is substantially the same.

  The sheet roll (19) is illustrated so that it can move along with the nonwoven fabric wound in the longitudinal direction of the axis (direction perpendicular to the paper surface), that is, the width direction of the intermediate sheet, and adjust the position in the width direction. The intermediate sheet supply drum width direction position adjusting device is not included.

  A suction box (22) is disposed below the wire (9) at the downstream side (moving terminal portion on the upper surface of the wire). This suction box (22) sucks and squeezes water contained in the lower paper layer (8), the intermediate sheet and the upper paper material layer (6) in the downstream portion of the wire (9) in the paper making process. Water.

  The multilayer laminated paper formed of the wire (9) is guided by a guide roll (not shown) and wound up by a winding roll as a final product. Between the wire (9) and the winding roll, from the upstream side. A press part top roll (1), a press part bottom roll (3), a paper roll (29, 30, 31), and a drying device (23) are disposed.

  A press part top roll (1) and a press part bottom roll (3) pinch | interpose multilayer laminated paper, and also send it to a downstream winding roll (25). The drying device (23) uses a known drying device.

  The produced papermaking roll can be used not only for the press section top roll (1) that is in direct contact with the wet paper, but also for the paper roll (29, 30, 31). The effect of eliminating defects and delamination can be expected. However, the present invention is not limited to this, and any roll can be used as long as the roll is installed in front of the drying device (23) in the paper machine (28). Furthermore, the roll for papermaking of the present invention can be used not only for the long paper machine but also for the circular paper machine as long as the wet paper is in contact with the roll.

  A groove is provided in the papermaking roll under the conditions of a triangular shape with a bite angle of 60 degrees, a constant groove pitch of 1.0 mm, a groove depth of 0.3 mm, a nip width of 5.0 mm, and an effective surface length of the papermaking roll of 1000 mm. An example of the case will be described with reference to FIG.

  As a papermaking roll, a hard rubber roll having a surface hardness of A70 is used, and with respect to the surface of the papermaking roll, a cutting tool with a blade tip angle of 60 degrees is used on the surface of the papermaking roll under the conditions described below. A groove was formed.

  As shown in FIG. 10, the cross-section of the groove (2) also becomes a triangular shape by using a processing tool with a tip having a tip angle of 60 degrees, and the groove width is divided into two equal parts: the groove width. The length from the beginning of the groove to the low point of the groove: The length from the low point of the groove to the surface of the paper roll is perpendicular to the ratio of 1: 2: √3. The groove width is calculated by (groove depth / √3 × 2), and the contact length is calculated by (groove pitch−groove width).

  When the pitch of the formed grooves is 1.0 mm and the groove depth is 0.3 mm, the groove width is (groove depth / √3 × 2) = (0.3 mm / √3 × 2) = 0.3464 mm. The contact length is (groove pitch-groove width) = (1.0 mm−0.3464 mm) = 0.6536 mm.

Next, the total contact area between the wet paper and the papermaking roll is calculated. The contact area between the pitches of the grooves is (contact length × nip width) = (0.6536 mm × 5.0 mm) = 3.2680 mm ² . Next, the number of contacts within the effective surface length of the papermaking roll is (effective surface length of the papermaking roll / groove pitch) = (1000 mm / 1.0 mm) = 1000. The total contact area between the wet paper and the papermaking roll is (contact area between the pitches of the grooves × number of contacts within the effective surface length of the papermaking roll) = (3.2680 mm ² × 1000) = 3268 mm ² .

  Therefore, the contact area ratio between the wet paper and the papermaking roll is 65.3%.

The papermaking roll thus produced was installed at the location of the press top roll (1) which is the roll on the side in direct contact with the wet paper in the dehydration step of the single-layer paper manufacturing apparatus shown in FIG. . The paper making speed during paper making was 30 m. Type of paper, and quality paper, the paper layer structure was papermaking monolayers paper having a basis weight of ^{70g / m 2 ~100g / m 2} .

  As shown in FIG. 16, assuming that the wet paper holding angle on the inlet side is a, the wet paper holding angle on the outlet side when paper separation is good is b, and the wet paper holding angle when paper separation is bad is c, b ≦ a < c. When the papermaking roll in the present invention is not used, the wet paper is in close contact with the press portion top roll as shown in FIG. 17 and the paper separation is bad, but by using the papermaking roll in the present invention, b ≦ As a result, a high peeling effect between the wet paper and the press portion top roll was obtained, and the problem of paper separation failure and delamination was solved.

  A groove is provided in the papermaking roll under the conditions of a triangular shape with a bite angle of 60 degrees, a constant groove pitch of 10.0 mm, a groove depth of 0.03 mm, a nip width of 5.0 mm, and an effective surface length of the papermaking roll of 1000 mm. An example of the case will be described with reference to FIG.

  As a papermaking roll, a hard rubber roll having a surface hardness of A100 is used, and with respect to the surface of the papermaking roll, a cutting tool with a blade tip angle of 60 degrees is used on the surface of the papermaking roll under the conditions described below. A groove was formed.

  As shown in FIG. 11, the groove (2) has a triangular cross-section by using a processing tool with a tip having a tip angle of 60 degrees, and the width of the groove is divided into two: the groove width The length from the beginning of the groove to the low point of the groove: The length from the low point of the groove to the surface of the paper roll is perpendicular to the ratio of 1: 2: √3. Therefore, the groove width is calculated by (groove depth / √3 × 2), and the contact length is calculated by (groove pitch−groove width).

  As conditions for the formed grooves, the pitch of the grooves was 10.0 mm, and the depth of the grooves was 0.03 mm. In that case, the width of the groove is (groove depth / √3 × 2) = (0.03 mm / √3 × 2) = 0.0346 mm. The contact length is (groove pitch-groove width) = (1.0 mm−0.0346 mm) = 9.9654 mm.

  When the groove pitch is 1.0 mm to 10.0 mm, the groove depth is 0.03 mm to 0.3 mm, and the machining bite angle is 60 degrees, the groove width range is 0.0346 mm to 0.346 mm. It becomes. When the width of the groove is smaller than 0.0346 mm, there arises a problem that it is difficult to obtain the effect of improving the water retention of the roll surface. Conversely, if the groove width is larger than 0.346 mm, the water retention becomes too high, resulting in a problem of poor paper texture.

  The range of the contact length is 0.6536 mm to 9.9654 mm. When the width of the groove is smaller than 0.6536 mm, there arises a problem that it is difficult to obtain the effect of improving the water retention of the roll surface. In addition, when the width of the groove is larger than 9.9654 mm, the water retention becomes too high, resulting in a problem of poor paper texture.

Next, the total contact area between the wet paper and the papermaking roll is calculated. First, the contact area between the pitches of the grooves is (contact length × nip width) = (9.9654 mm × 5.0 mm) = 49.827 m ² . Next, the number of contacts within the effective surface length of the papermaking roll is (effective surface length of the papermaking roll / groove pitch) = (1000 mm / 10.0 mm) = 100. Next, the total contact area between the wet paper and the papermaking roll is (contact area between pitches of grooves × number of contacts within the effective surface length of the papermaking roll) = (49.88 mm ² × 100) = 4983 mm ² Become.

The groove pitch is 1.0 mm to 10.0 mm, the groove depth is 0.03 mm to 0.3 mm, the working bite angle is 60 degrees, the effective surface length of the papermaking roll is 1000 mm, and the nip width is 5.0 mm. In some cases, the range of the contact area between the wet paper and the papermaking roll is 3265 mm ^{2 to} 4933 mm ² . When the contact area between the wet paper and the papermaking roll is smaller than 3265 mm ² , the water retention on the surface of the papermaking roll becomes too high, resulting in a problem of poor paper texture. On the other hand, when the contact area between the wet paper and the papermaking roll is larger than 4933 mm ² , the water retention on the surface of the papermaking roll is lowered and the peeling effect between the wet paper and the papermaking roll is lowered.

  Therefore, the contact area ratio between the wet paper and the papermaking roll is 99.0%. The groove pitch is 1.0 mm to 10.0 mm, the groove depth is 0.03 mm to 0.3 mm, the working bite angle is 60 degrees, the effective surface length of the papermaking roll is 1000 mm, and the nip width is 5.0 mm. In some cases, the range of the contact area ratio between the wet paper and the papermaking roll is 65.3% to 99.0%. When the contact area between the wet paper and the papermaking roll is smaller than 65.3%, the water retention on the surface of the papermaking roll becomes too high, resulting in a problem of poor paper texture. Further, when the contact area between the wet paper and the papermaking roll is larger than 99.0%, the water retention on the surface of the papermaking roll is lowered, and the peeling effect between the wet paper and the papermaking roll is lowered.

The papermaking roll thus produced was provided at the place of the press part top roll (1) which is a roll on the side in direct contact with the wet paper in the dewatering step of the multilayer paper manufacturing apparatus shown in FIG. The paper making speed during paper making was 30 m. Type of paper, and quality paper, the paper layer structure ^was papermaking low basis weight of the multilayer sheet of ^{30g / m 2 ~70g / m 2} .

  As shown in FIG. 16, assuming that the wet paper holding angle on the inlet side is a, the wet paper holding angle on the outlet side when paper separation is good is b, and the wet paper holding angle when paper separation is bad is c, b ≦ a < c. When the papermaking roll in the present invention is not used, the wet paper is in close contact with the press portion top roll as shown in FIG. 17 and the paper separation is bad, but by using the papermaking roll in the present invention, b ≦ As a result, a high peeling effect between the wet paper and the press portion top roll was obtained, and the problem of paper separation failure and delamination was solved.

  Grooves are provided in the papermaking roll under the conditions of a triangular shape with a bite angle of 90 degrees, a constant groove pitch of 1.0 mm, a groove depth of 0.03 mm, a nip width of 5.5 mm, and an effective surface length of the papermaking roll of 1000 mm. An example of the case will be described with reference to FIG.

  As a papermaking roll, a hard rubber roll having a surface hardness of A100 is used, and with respect to the surface of the papermaking roll, an NC lathe is used with a cutting tool with a blade tip angle of 90 degrees, under the conditions described below. A groove was formed.

  As the conditions of the formed groove, the groove pitch was 1.0 mm, and the groove depth was 0.03 mm. As shown in FIG. 12, the cross section of the groove (2) has a triangular shape, and the length obtained by dividing the groove width into two equal parts: the length from the beginning of the groove width to the low point of the groove: papermaking from the low point of the groove The length tied to the surface of the roll for use at a right angle has a ratio of 1: √2: 1. In this case, the width of the groove is (groove depth × 2) = (0.03 mm × 2) = 0.06 mm. The contact length is (groove pitch-groove width) = (1.0 mm−0.06 mm) = 0.94 mm.

Next, the total contact area between the wet paper and the papermaking roll is calculated. First, the contact area between the pitches of the grooves is (contact length × nip width) = (0.94 mm × 5.5 mm) = 5.17 mm ² . Next, the number of contacts within the effective surface length of the papermaking roll is (effective surface length of the papermaking roll / groove pitch) = (1000 mm / 1.0 mm) = 1000. Next, the total contact area between the wet paper and the papermaking roll is (contact area between pitches of grooves × number of contacts within the effective surface length of the papermaking roll) = (5.17 mm ² × 1000) = 5170 mm ² Become.

  Therefore, the contact area ratio between the wet paper and the papermaking roll is 94.0%.

The papermaking roll thus produced was installed at the location of the press top roll (1) which is the roll on the side in direct contact with the wet paper in the dehydration step of the single-layer paper manufacturing apparatus shown in FIG. . The paper making speed at the time of paper making was 30 m. Type of paper, and quality paper, the paper layer structure was papermaking monolayers paper having a basis weight of ^{70g / m 2 ~100g / m 2} .

  As shown in FIG. 16, assuming that the wet paper holding angle on the inlet side is a, the wet paper holding angle on the outlet side when paper separation is good is b, and the wet paper holding angle when paper separation is bad is c, b ≦ a < c. When the papermaking roll in the present invention is not used, the wet paper is in close contact with the press portion top roll as shown in FIG. 17 and the paper separation is bad, but by using the papermaking roll in the present invention, b ≦ As a result, a high peeling effect between the wet paper and the press portion top roll was obtained, and the problem of paper separation failure and delamination was solved.

  Under the conditions of a triangular shape with a bite angle of 90 degrees, irregular within a groove pitch of 1.0 mm to 10.0 mm, a groove depth of 0.3 mm, a nip width of 5.0 mm, and an effective surface length of a paper roll of 1000 mm An example in which grooves are provided in the papermaking roll will be described with reference to FIG.

  As a papermaking roll, a hard rubber roll having a surface hardness of A100 is used, and with respect to the surface of the papermaking roll, a cutting tool with a blade tip angle of 90 degrees is used on the surface of the papermaking roll under the conditions described below. A groove was formed.

  As conditions for the formed grooves, three types of groove pitches of 2.0 mm, 3.0 mm, and 4.0 mm were used, and the groove depth was 0.3 mm. In this case, as shown in FIG. 13, the width of the groove (a in FIG. 13) is (groove depth × 2) = (0.3 mm × 2) = 0.6 mm. Further, when the groove pitch (c + β in FIG. 13) is 2.0 mm, the contact length (b + β in FIG. 13) is (groove pitch−groove width) = (2.0 mm−0. 6 mm) = 1.4 mm, and the contact length (b in FIG. 13) when the groove pitch (c in FIG. 13) is 3.0 mm is (groove pitch−groove width) = (3.0 mm− 0.6 mm) = 2.4 mm, and the contact length (b + α in FIG. 13) when the groove pitch (c + α in FIG. 13) is 4.0 mm is (groove pitch−groove width). = (4.0 mm-0.6 mm) = 3.4 mm.

Next, the total contact area between the wet paper and the papermaking roll is calculated. The contact area between the groove pitches when the groove pitch is 1.0 mm is (contact length × nip width) = (1.4 mm × 5.0 mm) = 7.0 mm ² . The number of contacts within the effective surface length of the papermaking roll is (effective surface length of the papermaking roll / groove pitch) = (1000 mm / 2.0 mm) = 500. The total contact area between the wet paper and the papermaking roll is (contact area between the pitches of the grooves × number of contacts within the effective surface length of the papermaking roll) = (7.0 mm ² × 500) = 3500 mm ² . Therefore, the contact area ratio between the wet paper and the papermaking roll is 70.0%.

The contact area between the groove pitches when the groove pitch is 3.0 mm is (contact length × nip width) = (2.4 mm × 5.0 mm) = 12.0 m ² . Next, the number of contacts within the effective surface length of the papermaking roll is (effective surface length of the papermaking roll / groove pitch) = (1000 mm / 3.0 mm) = 333. Then, the total contact area of the wet paper and papermaking rolls, and (contact number in the effective face length of roll contact area × papermaking between groove pitch) = (12.0 mm ² × 333 present) = 3996mm ² Become. Therefore, the contact area ratio between the wet paper and the papermaking roll is 80.0%.

The contact area between the groove pitches when the groove pitch is 4.0 mm is (contact length × nip width) = (3.4 mm × 5.0 mm) = 17.0 m ² . Next, the number of contacts within the effective surface length of the papermaking roll is (effective surface length of the papermaking roll / groove pitch) = (1000 mm / 4.0 mm) = 250. Then, the total contact area of the wet paper and papermaking rolls, and (contact number in the effective face length of roll contact area × papermaking between groove pitch) = (17.0 mm ² × 250 present) = 4250mm ² Become. Therefore, the contact area ratio between the wet paper and the papermaking roll is 85.0%.

  When the groove pitch is 2.0 mm, 3.0 mm, and 4.0 m, the contact area ratio between the wet paper and the papermaking roll is 70.0%, 80.0%, and 85.0%, respectively. From this, grooves were formed in the papermaking roll by a combination such that the contact area ratio between the wet paper and the papermaking roll was in the range of 60% to 99%.

The papermaking roll thus produced was installed at the location of the press top roll (1) which is the roll on the side in direct contact with the wet paper in the dehydration step of the single-layer paper manufacturing apparatus shown in FIG. . The paper making speed during paper making was 30 m. Type of paper, and quality paper, the paper layer structure, the low basis weight monolayer paper having a basis weight of ^{30g / m 2 ~70g / m 2} , and functional paper having a basis weight of ^70g / ^{m 2 ~100g} / m 2 Made.

  As shown in FIG. 16, assuming that the wet paper holding angle on the inlet side is a, the wet paper holding angle on the outlet side when paper separation is good is b, and the wet paper holding angle when paper separation is bad is c, b ≦ a < c. When the papermaking roll in the present invention is not used, the wet paper is in close contact with the press portion top roll as shown in FIG. 17 and the paper separation is bad, but by using the papermaking roll in the present invention, b ≦ As a result, a high peeling effect between the wet paper and the press portion top roll was obtained, and the problem of paper separation failure and delamination was solved.

  When the groove is provided on the papermaking roll under the conditions that the groove shape is a square shape, the groove pitch is 1.0 mm, the groove depth is 0.3 mm, the nip width is 5.0 mm, and the effective surface length of the papermaking roll is 1000 mm. An example will be described with reference to FIG.

  As a papermaking roll, a hard rubber roll having a surface hardness of A100 is used, and a rectangular groove is formed on the surface of the papermaking roll using a 0.03 mm laser engraving machine under the conditions described below. did.

  As the conditions for the formed grooves, the groove pitch was 1.0 mm and the groove depth was 0.3 mm. As shown in FIG. 14, the groove (2) has a square cross section, and the width of the groove becomes 0.03 mm by irradiation with a laser engraving machine. The contact length is (groove pitch-groove width) = (1.0 mm−0.03 mm) = 0.97 mm.

Next, the total contact area between the wet paper and the papermaking roll is calculated. First, the contact area between the pitches of the grooves is (contact length × nip width) = (0.97 mm × 5.0 mm) = 4.85 mm ² . Next, the number of contacts within the effective surface length of the papermaking roll is (effective surface length of the papermaking roll / groove pitch) = (1000 mm / 1.0 mm) = 1000. Then, the total contact area of the wet paper and papermaking rolls, and (contact number in the effective face length of roll contact area × papermaking between groove pitch) = (4.85 mm ² × 1000 present) = 4850mm ² Become.

  Therefore, the contact area ratio between the wet paper and the papermaking roll is 97.0%.

The papermaking roll thus produced was installed at the location of the press top roll (1) which is the roll on the side in direct contact with the wet paper in the dehydration step of the single-layer paper manufacturing apparatus shown in FIG. . The paper making speed during paper making was 30 m. Type of paper, and quality paper, the paper layer structure was papermaking monolayers paper having a basis weight of ^{70g / m 2 ~100g / m 2} .

  As shown in FIG. 16, assuming that the wet paper holding angle on the inlet side is a, the wet paper holding angle on the outlet side when paper separation is good is b, and the wet paper holding angle when paper separation is bad is c, b ≦ a < c. When the papermaking roll in the present invention is not used, the wet paper is in close contact with the press portion top roll as shown in FIG. 17 and the paper separation is bad, but by using the papermaking roll in the present invention, b ≦ As a result, a high peeling effect between the wet paper and the press portion top roll was obtained, and the problem of paper separation failure and delamination was solved.

  When the groove is provided on the papermaking roll under the conditions that the groove shape is circular, the groove pitch is 1.0 mm, the groove depth is 0.3 mm, the nip width is 5.0 mm, and the effective surface length of the papermaking roll is 1000 mm. An example will be described with reference to FIG.

  As a papermaking roll, a hard rubber roll with a surface hardness of A100 is used, and a circular groove is formed on the surface of the papermaking roll using a 0.03 mm laser engraving machine under the conditions described below. did.

  As the conditions for the formed grooves, the groove pitch was 1.0 mm and the groove depth was 0.3 mm. The cross section of the groove is circular, and the width of the groove is 0.03 mm by irradiation with a laser engraving machine. The contact length is (groove pitch-groove width) = (1.0 mm−0.03 mm) = 0.97 mm.

Next, the total contact area between the wet paper and the papermaking roll is calculated. First, the contact area between the pitches of the grooves is (contact length × nip width) = (0.97 mm × 5.0 mm) = 4.85 mm ² . Next, the number of contacts within the effective surface length of the papermaking roll is (effective surface length of the papermaking roll / groove pitch) = (1000 mm / 1.0 mm) = 1000. Then, the total contact area of the wet paper and papermaking rolls, and (contact number in the effective face length of roll contact area × papermaking between groove pitch) = (4.85 mm ² × 1000 present) = 4850mm ² Become.

  Therefore, the contact area ratio between the wet paper and the papermaking roll is 97.0%.

The papermaking roll thus produced was installed at the location of the press top roll (1) which is the roll on the side in direct contact with the wet paper in the dehydration step of the single-layer paper manufacturing apparatus shown in FIG. . The paper making speed at the time of paper making was 30 m. Type of paper, and quality paper, the paper layer structure was papermaking monolayers paper having a basis weight of ^{70g / m 2 ~100g / m 2} .

  As shown in FIG. 16, assuming that the wet paper holding angle on the inlet side is a, the wet paper holding angle on the outlet side when paper separation is good is b, and the wet paper holding angle when paper separation is bad is c, b ≦ a < c. When the papermaking roll in the present invention is not used, the wet paper is in close contact with the press portion top roll as shown in FIG. 17 and the paper separation is bad, but by using the papermaking roll in the present invention, b ≦ As a result, a high peeling effect between the wet paper and the press portion top roll was obtained, and the problem of paper separation failure and delamination was solved.

  As can be seen from Examples 1, 2, 3, 4, 5 and 6 above, by using the paper-making roll having grooves formed therein, particularly for the press section top roll (1), single-layer paper, multilayer paper, and It was confirmed that the effect of improving peelability was obtained in common with functional paper.

The front view of the papermaking roll in this invention is shown. An example of the shape of the groove | channel of the papermaking roll in this invention is shown. An example of the pitch of the groove | channel of the papermaking roll in this invention is shown. The contact area between the pitches of the grooves of the papermaking roll in the present invention, the number of contacts within the effective surface length of the papermaking roll, and the total contact area of the wet paper and the papermaking roll are shown. The side view of the papermaking roll in this invention is shown. The contact area rate per predetermined area of the papermaking roll and wet paper in the present invention is shown. An example of the shape of the groove | channel which looked at the surface of the papermaking roll in this invention from the upper part is shown. The whole structure of the manufacturing apparatus of the single layer paper in this invention is shown. The whole structure of the manufacturing apparatus of the multilayer paper in this invention is shown. The method for calculating the groove width and the groove length when the groove of the papermaking roll in the present invention is formed in a triangular shape with a processing bite of 60 degrees is shown. The method for calculating the groove width and the groove length when the groove of the papermaking roll in the present invention is formed in a triangular shape with a processing bite of 60 degrees is shown. The method for calculating the groove width and the groove length when the grooves of the papermaking roll according to the present invention are formed in a triangular shape with a working bite of 90 degrees is shown. The method for calculating the groove width and the groove length when the grooves of the papermaking roll in the present invention are formed in a triangular shape with a processing bite of 90 degrees and the groove pitches are varied will be shown. The calculation method of the width | variety of a groove | channel and the length of a groove | channel at the time of forming the groove | channel of the papermaking roll in this invention in square shape is shown. The calculation method of the difference of the width | variety of the groove | channel and groove | channel length at the time of forming the groove | channel of the papermaking roll in this invention in circular shape is shown. The holding angle of the papermaking roll and wet paper in the present invention is shown. The state of peeling failure is shown.

Explanation of symbols

1 Press part top roll 2 Groove 3 Press part bottom roll 4 Wet paper 5 Felt 6 Upper paper layer (Wet paper)
7 Intermediate sheet 8 Lower layer (wet paper)
9 Wire (paper network)
10 Suction couch roll 11 Breast roll 12 Lower layer stock supply tank,
13 Intermediate sheet supply device 14 Upper layer stock supply tank 15 Lower layer stock 16 Upper layer stock 17, 17a, 17b, 17c Seal plate for lower layer stock (slice plate)
18 Sealing plate for upper layer paper 19 Sheet roll 20 Feeding roll 21 Dancer roll 22 Suction box (dehydrating device)
23 Drying device 24 Dandy roll 25 Take-up roll 26 Wet paper separation failure or delamination 27 Middle layer and lower layer mat 28 in delamination state Paper machine 29, 30, 31 Paper roll

Claims (2)

In a papermaking roll in contact with a wet paper having a moisture content of 30 to 95%, which is installed in a paper machine having a paper supply unit, a dewatering unit, a press unit and a drying unit,
Forming grooves on the surface of the papermaking roll,
The papermaking roll, wherein the groove is provided so that a contact area ratio between the wet paper and the papermaking roll is in a range of 60% to 99% per predetermined area. The papermaking roll according to claim 1, wherein the groove has a pitch of 1.0 mm to 10.0 mm and a depth of 0.03 mm to 0.3 mm.

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