JP2011156630A - Method of polishing ceramic roll for papermaking process, and ceramic roll for papermaking process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of polishing a ceramic roll for forming a roll surface with an enhanced separability from paper, while having a smoothing function for paper in a press part and the like in a papermaking process, and to provide the ceramic roll for the papermaking process obtained by this method of polishing. <P>SOLUTION: The method of polishing the ceramic roll for the papermaking process includes: a rough polishing process for roughly polishing the outer circumferential surface of the ceramic roll for the papermaking process; an intermediate polishing process for adjusting the roughness of the roughly polished outer circumferential surface of the ceramic roll for the papermaking process; and a directional zone forming process for forming a directional zone on the outer circumferential surface, the roughness of which has been adjusted, of the ceramic roll for the papermaking process. The directional zone has a scratch forming surface with a main direction inclined with respect to the circumferential direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for polishing a ceramic roll used when dehydrating wet paper in a press part or the like in a papermaking process, and to a ceramic roll for a papermaking process obtained by this method.

  In the paper making process in papermaking, it is necessary to remove a large amount of water contained in the wet paper that has been made and dry it. As a method for removing moisture from the wet paper, a press part is usually provided that dehydrates the wet paper held on the felt between two rolls and pressurizes in the paper making process. As a roll used in this press part, a roll having a hard surface is used as at least one of the two rolls for dehydration by pressurization and imparting smoothness to the wet paper surface.

  The above-mentioned roll with a hard surface is required to be a material that can withstand high loads, high-speed rotation, and long-term use, and stone rolls using natural granite have been used for a long time. Since this stone roll can be mirror-finished, it has a high smoothness-imparting function on paper and has high surface hardness, so it has low wear and can withstand the above-mentioned high loads, high-speed rotation and long-term use. Is possible. However, since stone rolls are made of natural stone, they are becoming difficult to obtain. In addition, it is extremely difficult to quarry, transport, and process large stone materials for rolls that are long and large. Furthermore, since the stone roll is a natural material, there is a disadvantage that the surface characteristics such as hardness vary for each roll to be manufactured or for each portion of one roll.

  Therefore, ceramic rolls having a ceramic layer sprayed on the surface by a gas plasma spraying method or the like are being widely adopted as rolls instead of stone rolls. Since such a ceramic roll has a dense ceramic layer provided on the surface by thermal spraying, the roll surface is highly smooth.

  Such a ceramic roll having a high surface smoothness can improve the paper surface smoothness. On the other hand, if the smoothness is too high, the adhesion between the roll surface and the wet paper becomes too high, and the paper peels off. Sex is reduced. Thus, when the paper peelability of the roll surface is low, the wet paper web surface portion may be peeled off when the wet paper passes through the press roll. The debris on the surface of the wet paper that has been peeled off adheres to the roll surface, which causes a reduction in paper quality. In addition, if the peelability from the paper is low, a paper break may occur in the process after the press roll, and the production line may be stopped.

  When such a ceramic roll is used for a long time in a press part, the surface is gradually worn by contact with the wet paper and the smoothness is increased, and in addition, the roll central portion is worn and the surface tends to be curved.

  Accordingly, in order to control the smoothness of the surface of the ceramic roll, the surface is polished so as to have an appropriate surface roughness in the manufacturing process and in the regular maintenance (Japanese Patent Laid-Open No. 9-9 / 1999). 241820). As this surface polishing method, for example, after rough polishing, finish polishing is performed with a polishing grindstone or a polishing film. In this finish polishing, in the case of a polishing grindstone, a polishing film having a particle size of # 120 to # 1000 is used. In this case, by using particles made of abrasive particles of 15 μm to 100 μm, the level difference (Rk) of the core part, the load length ratio (Mr2) of the core part, and the protruding valley part depth (Rvk) are obtained as the surface roughness. A control method has been proposed (see Japanese Patent Application Laid-Open No. 2005-273090).

  However, according to the roll for the papermaking process in which the surface roughness of the roll surface is simply controlled by using a specific abrasive as described above, pulp fibers on the surface of the wet paper may be clogged by scratches caused by polishing. However, there is a limit to improving the paper peelability. Therefore, it is desired to develop a method for polishing a ceramic roll that can provide a roll surface having higher paper peelability while providing a smoothness imparting function to paper in a press part or the like in a papermaking process.

JP-A-9-241820 JP 2005-273090 A

  The present invention has been made in view of these circumstances, and in a press part or the like in a paper making process, the roll surface having a high peelability from paper can be provided while having a function of imparting smoothness to paper. An object of the present invention is to provide a ceramic roll polishing method and a ceramic roll for paper making process obtained by this polishing method.

The invention made to solve the above problems is
A rough polishing step for rough polishing the outer peripheral surface of the ceramic roll for papermaking process;
A semi-finishing process for adjusting the roughness of the outer surface of the ceramic roll for papermaking process;
A directional region forming step of forming a directional region by polishing on the outer peripheral surface of a ceramic roll for papermaking process,
This is a polishing method for a ceramic roll for papermaking process in which the main direction of the scratches in the directional region is inclined with respect to the circumferential direction.

  According to the method for polishing a ceramic roll for papermaking process, a directional region having a scratch eye in which the main direction is inclined with respect to the circumferential direction of the ceramic roll while giving a desired roughness to the outer circumferential surface of the ceramic roll. Can be formed on the outer peripheral surface of the ceramic roll. Since the directional region having such scratches is formed on the outer peripheral surface of the ceramic roll for paper making process polished by the method, the wet paper made in this directional region is formed in the press part of the paper making step. The fiber orientation direction and the main direction of the scratch eyes can be different directions. Therefore, when the thus-polished ceramic roll for paper making process is used in a press part, the pulp fiber on the wet paper surface is less likely to be buried in the fine scratches in the directional region, thus improving the peelability from the paper. be able to. On the other hand, since the ceramic roll obtained by the polishing method is polished so as to have a desired roughness, sufficient smoothness can be imparted to the paper.

In the directional region forming step,
Using a belt-shaped diamond grindstone that can be circulated across multiple rolls,
The outer peripheral surface of the papermaking process ceramic roll and the outer surface of the belt-shaped diamond grinding wheel are brought into contact with each other, and the belt-shaped diamond grinding stone is oscillated in the axial direction of the papermaking process ceramic roll while rotating the papermaking process ceramic roll. Good.

  According to the method of polishing a ceramic roll for papermaking process, the belt-shaped diamond grinding wheel is oscillated in the axial direction of the ceramic roll for papermaking process while rotating the ceramic roll for papermaking process. The main direction of the eyes can be formed in a zigzag shape along the circumferential direction. Thus, according to the ceramic roll in which the main direction of the scratch eyes is formed in a zigzag shape, the difference between the fiber orientation direction of the wet paper and the main direction of the scratch eyes is caused by the presence of the conversion portion of the main direction in this directional region. Even if it is small, the pulp fibers of the wet paper are less likely to be buried in the scratches. Therefore, according to the ceramic roll obtained by the polishing method, the peelability from paper can be further improved. The zigzag shape means not only a shape in which a straight line is bent but also a shape in which a curve is bent.

  The belt-shaped diamond grindstone has a plurality of diamond grindstone regions disposed on the outer surface, and the diamond grindstone regions are disposed in a grid pattern at equal intervals in the longitudinal direction and the width direction of the belt-shaped diamond grindstone. It is good to have. According to the polishing method, by providing the diamond grindstone region in this way, the directional region of the ceramic roll can be formed into a strip shape, and the directional region is along the axial direction of the ceramic roll. Can be formed at regular intervals. The ceramic roll obtained by such a polishing method is provided with alternating directional regions and other regions in the axial direction. Therefore, according to the ceramic roll obtained by the polishing method, it is possible to further prevent the pulp fibers from being buried together in the scratches and further improve the peelability from the paper. Note that “arranged in a grid pattern” means that each grid is disposed at each grid position.

  The diamond grinding wheel region is a regular square, and the length of one side of the regular square is preferably 3 mm or more and 7 mm or less. According to the polishing method, by making the diamond grindstone region as described above, a ceramic roll for papermaking process having higher releasability from paper can be obtained.

  It is preferable to further include an adjustment finishing step for adjusting the roughness of the outer peripheral surface of the papermaking process ceramic roll in which the directional region is formed. According to the polishing method, by having the adjustment finishing step after the directional region forming step, it is possible to obtain a ceramic roll that achieves both higher levels of peelability from paper and smoothness imparting function to paper.

  Therefore, the ceramic roll for papermaking process obtained by the polishing method has a high peelability from paper while having a function of imparting smoothness to paper.

  Here, the “scratch eyes” refer to fine streak-like polishing marks formed by polishing using an abrasive such as a grindstone or a polishing film.

  As explained above, according to the polishing method of the ceramic roll for papermaking process, the press roll part in the papermaking process gives high smoothness to the wet paper, and in addition, the ceramic roll has high peelability from the wet paper Can be obtained. Therefore, by using the ceramic roll for papermaking process obtained by such a polishing method, it is possible to prevent the paper quality from being lowered and to improve the productivity.

The typical top view (a) and typical side view (b) which show the grinding | polishing method of the ceramic roll for papermaking processes which concerns on one Embodiment of this invention. The typical partial enlarged view which shows the outer peripheral surface of the ceramic roll for papermaking processes obtained by the grinding method of the ceramic roll for papermaking processes of FIG. The typical partial enlarged view which shows the surface of the ceramic roll for papermaking processes different from the ceramic roll for papermaking processes of FIG.

Hereinafter, embodiments of the present invention will be described in detail in the order of a method for polishing a ceramic roll for papermaking process and a ceramic roll for papermaking process obtained by this polishing method, with reference to the drawings as appropriate.
The polishing method of the ceramic roll for papermaking process of the present invention,
(1) A rough polishing step for rough polishing the outer peripheral surface of the ceramic roll for paper making process,
(2) a medium finishing step for adjusting the roughness of the outer peripheral surface of the paper roll for the papermaking process, and (3) a directional region forming step for forming a directional region by polishing on the outer peripheral surface of the paper roll for the ceramic roll And if necessary,
(4) An adjustment finishing step for adjusting again the roughness of the outer peripheral surface of the papermaking process ceramic roll in which the directional region is formed. Although the order of the steps (1) to (3) of the polishing method is not particularly limited, it is performed in the order of the above-described (1) rough polishing step, (2) intermediate finishing step, and (3) directional region forming step. Is preferred. However, for example, (2) the intermediate finishing step and (3) the directional region forming step may be reversed.

  First, a ceramic roll for paper making process polished by the polishing method of the present invention will be described with reference to FIG. 1, mainly FIG. 1 (b).

  The ceramic roll 1 for paper making process in FIG. 1 mainly includes a roll body 2 and a ceramic layer 3 laminated on the outer peripheral surface side of the roll body 2.

  As the roll main body 2, one that is generally employed in a press part in the paper making process can be used. The roll main body 2 is formed of a cast steel roll shell 4 formed in a cylindrical shape and having a predetermined thickness, a disk-shaped head 5 fitted to both ends of the roll shell 4, and the center of each head 5. And a shaft 6 projecting outward.

The ceramic layer 3 is laminated on the outer peripheral surface of the roll shell 4. It does not specifically limit as a ceramic which forms this ceramic layer 3, A well-known thing can be used. Further, the thickness of the ceramic layer 3 is not particularly limited. The ceramic layer 3 can be laminated by, for example, spraying ceramic powder obtained by mixing titania (TiO ₂ ) in a proportion of 10% to 65% with respect to alumina (Al ₂ O ₃ ).

  The surface of such a ceramic roll 1 is usually smoothed by long-term use. The surface roughness (Ra) of the outer peripheral surface of the ceramic roll 1 before polishing is, for example, about 0.7 μm or more and 0.8 μm or less. When the ceramic roll 1 having a smooth surface as described above is used for a press part in a papermaking process, the paper separation property is lowered, and thus the surface needs to be polished. The surface roughness (Ra) in the present specification is a value measured according to JIS-B0601 (1994) with a cutoff λc of 2.5 mm and an evaluation length of 12.5 mm.

  Next, each step will be specifically described.

(1) Rough polishing step In this rough polishing step, the outer peripheral surface of the paper roll ceramic roll smoothed by long-term use is roughened to a certain level. The abrasive used in the rough polishing step is not particularly limited, and an abrasive generally used for polishing a ceramic roll for paper making process such as a wheel-shaped diamond grindstone can be used. As a polishing method using the wheel-shaped diamond grindstone, for example, the wheel-shaped diamond grindstone can be brought into contact with the outer peripheral surface of the ceramic roll 1 while rotating the ceramic roll 1 in the circumferential direction. At this time, the wheel-shaped diamond grindstone may or may not be rotated. In addition, when rotating a wheel-shaped diamond grindstone, it will rotate in the same direction as the rotation direction of the ceramic roll 1. The surface roughness (Ra) of the outer peripheral surface of the ceramic roll that has undergone this rough polishing step is, for example, about 1.7 μm or more and 2.2 μm or less.

(2) Intermediate Finishing Process In this intermediate finishing process, the roughness is adjusted so that the outer peripheral surface of the papermaking process ceramic roll has a surface roughness suitable for the papermaking process ceramic roll. The abrasive used in the intermediate finishing step is not particularly limited, and an abrasive generally used for polishing a ceramic roll for a papermaking process such as a belt-like diamond film can be used.

  When a belt-shaped abrasive such as a belt-shaped diamond film is used, a finisher device can be used. This finisher device is a device for polishing a belt-shaped diamond film by rolling around the belt-shaped diamond film as necessary while rotating the plurality of rolls. Polishing using this finisher device is performed by rotating the ceramic roll in the circumferential direction and bringing the outer surface of the ceramic roll into contact with the outer surface of the diamond film attached to the finisher device.

  As the belt-like diamond film used in the intermediate finishing step, a polyester base cloth laminated with diamond abrasive grains having a particle size of # 320 or more and # 1000 or less is suitably used. In addition, it is preferable to perform stepwise adjustment to a desired surface roughness by performing polishing a plurality of times using a plurality of belt-shaped diamond films on which diamond abrasive grains having different particle sizes are laminated. The surface roughness (Ra) of the outer peripheral surface of the ceramic roll that has undergone such an intermediate finishing step is, for example, about 1.1 μm to 1.2 μm.

(3) Directional region forming step This directional region forming step will be described in detail with reference to FIGS. In the directional region forming step, the directional region 7 is formed on the outer peripheral surface of the ceramic roll 1 by polishing (see FIG. 2). This directional region 7 has a scratch eye whose main direction (the direction of arrow a in FIG. 2) is inclined with respect to the circumferential direction of the ceramic roll 1 (the direction of arrow b in FIG. 2).

  The paper roll process ceramic roll polished by the polishing method is formed with the directional region 7 having the above-described scratches, so that the fiber orientation direction of the wet paper made in this directional region 7; The main direction of the scratch eye can be different. Therefore, when the thus-polished ceramic roll for paper making process 1 is used in a press part or the like, the pulp fibers on the wet paper surface are less likely to be buried in fine scratches in the direction area 7 on the ceramic roll surface. Therefore, the peelability from the paper can be improved. On the other hand, the ceramic roll obtained by the polishing method is polished so as to have a desired roughness, so that sufficient smoothness can be imparted to the paper.

  Polishing in this directional region forming step can be performed using the finisher device 11 as in the above (2) intermediate finishing step.

  The finisher device 11 includes a plurality of rolls 12 and a belt-shaped diamond grindstone 13 that is circulated between the plurality of rolls 12.

  Polishing in the directional region forming step is performed by bringing the outer peripheral surface of the ceramic roll 1 and the outer surface of the belt-shaped diamond grindstone 13 provided in the finisher device 11 into contact with each other and rotating the ceramic roll 1 in the circumferential direction. Is called. At this time, the ceramic roll 1 and the plurality of rolls 12 provided in the finisher device 11 are arranged so that the axes of the rolls are parallel to each other.

  The finisher device 11 may be oscillated (vibrated) in the axial direction of the ceramic roll 1 (the direction of arrow a in FIG. 1). By oscillating the finisher device 11 in this way, the belt-shaped diamond grindstone 13 itself is oscillated in the axial direction of the ceramic roll 1.

  Thus, by rotating the belt-shaped diamond grindstone 13 in the axial direction of the papermaking process ceramic roll 1 while rotating the papermaking process ceramic roll 1, the main direction of the scratches in the directional region 7 can be changed. The zigzag can be formed along the circumferential direction of the ceramic roll 1. Thus, by forming the main direction of the scratch eyes in a zigzag shape, it is possible to provide a conversion portion of the main direction in the directional region 7, and there is a difference between the fiber orientation direction of the wet paper and the main direction of the scratch eyes. Even if it is small, the fibers are less likely to be buried in the scratches. Therefore, according to the ceramic roll 1 obtained by the said grinding | polishing method, the peelability of paper can be improved further.

  The finisher device 11 is preferably polished while moving in the axial direction (in the direction of arrow b in FIG. 1) from one end to the other end of the ceramic roll 1. Thus, by polishing while moving the finisher device 11, the main direction of the scratch eye is inclined with respect to the circumferential direction of the ceramic roll 1 regardless of the presence or absence of the oscillation motion or the vibration speed. Regions can be formed. Further, by polishing while moving the finisher device 11, even when the width of the belt-shaped diamond grindstone 13 is shorter than the length of the ceramic roll 1, the directional region 7 is formed on the entire outer peripheral surface of the ceramic roll 1. Can be formed.

  Further, the belt-shaped diamond grindstone 13 may be circulated during polishing or may not be circulated. When the belt-shaped diamond grindstone 13 is circulated, it is circulated in the same direction as the rotation direction of the ceramic roll 1. As described above, when the belt-shaped diamond grindstone 13 is ground while being circulated, the roughness of the belt-shaped diamond grindstone 13 at the contact portion with the ceramic roll 1 can be maintained, so that the polishing efficiency is improved.

  The belt-shaped diamond grindstone 13 includes a plurality of diamond grindstone regions 15 disposed on the outer surface of the base cloth 14.

  The base fabric 14 is not particularly limited as long as it has a certain strength, for example, a fabric knitted with synthetic fibers (polyester fibers, etc.) and cotton soaked in a resin solution to increase the strength. Used.

  The diamond grinding wheel region 15 is a region where the surface of the ceramic roll 1 can be polished, and is formed, for example, by laminating diamond abrasive grains having a grain size of # 320 to # 1000.

  The diamond grindstone region 15 is arranged in a grid pattern at equal intervals in the longitudinal direction and the width direction of the belt-shaped diamond grindstone 13. Since the diamond grindstone region is arranged in a grid pattern in this way, the directional region 7 can be formed into a strip shape when polished, and further, the directional region 7 is formed on the axis of the ceramic roll 1. It can be formed at regular intervals along the direction. In other words, the ceramic roll 1 obtained by the polishing method includes the directional regions 7 and the other regions alternately in the axial direction. Therefore, according to the ceramic roll 1 obtained by the polishing method, it is possible to further prevent the pulp fibers from being buried together in the scratches and further improve the peelability of the paper.

  The planar shape of the diamond grindstone region 15 is not particularly limited, and examples thereof include an elliptical shape, a rectangular shape, and a regular square shape. As the size when the diamond grinding wheel region 15 is a regular square, the length of one side is preferably 3 mm or more and 7 mm or less, and more preferably 4 mm or more and 6 mm or less. By making the diamond grindstone region 15 into a square having the above size, a ceramic roll for papermaking process having higher releasability from paper can be obtained. If the length of one side is smaller than 3 mm, the area of the directional region, particularly the width, becomes small, and there is a possibility that the paper separation property is not improved. On the other hand, if the length of one side is larger than 7 mm, the pulp fiber is likely to be buried in the scratch area in the directional region, so that there is a possibility that the paper separation property is not improved.

  Further, the distance between the diamond grinding wheel regions 15 when the diamond grinding wheel region 15 is a regular square is not particularly limited, but is preferably 1 mm or more and 5 mm or less in the longitudinal direction and the width direction from the viewpoint of paper separation. More preferably, it is 4 mm or less. If this distance is smaller than 1 mm, the area of the portion other than the directional region is reduced, and the pulp fibers are buried in the scratched area in the directional region, and the paper separation property may be reduced. On the other hand, when the distance exceeds 5 mm, the area of the portion other than the directional region becomes too large, and the function of the directional region is not sufficiently exhibited, and the paper separation property may be deteriorated.

  Further, when the diamond grindstone region 15 is arranged in a grid pattern and polished while circulating the belt-shaped diamond grindstone 13, by adjusting the rotational speed of the ceramic roll 1 and the circulating speed of the belt-shaped diamond grindstone 13, etc. It is also possible to obtain the paper roll process ceramic roll 21 in which the directional regions 27 as shown in FIG. 3 are formed in a strip shape.

  According to the polishing method, the shape (length, width, repetition length, interval, etc.) of the directional region can be adjusted by adjusting each polishing condition as described above. That is, according to the polishing method, the shape of the directional region formed on the outer peripheral surface of the ceramic roll can be easily adjusted in this way, and smoothness imparting properties corresponding to various papermaking having various properties can be achieved. In addition, it is possible to obtain a ceramic roll for a papermaking process that can achieve a high level of releasability from paper.

(4) Adjustment finishing process In this adjustment finishing process, the roughness of the outer peripheral surface of the ceramic roll 1 in which the directional region 7 is formed is adjusted again. Polishing in this adjustment finishing process can be performed using a finisher device using a belt-like diamond film similar to that in the intermediate finishing process as an abrasive.

  Through this adjustment finishing process, the roughness of the outer peripheral surface can be finally finished to an optimum roughness as a ceramic roll for papermaking process, and the function of imparting smoothness to the paper and paper is higher. It is possible to obtain a ceramic roll that is compatible at the level.

  In addition, (1) You may provide the deposit | attachment removal process which removes the deposit | attachment on the outer peripheral surface of a ceramic roll prior to a rough polishing process. As this deposit removal step, a method of polishing the roll surface with a silicon film or the like can be used.

  Next, the papermaking ceramic roll obtained by the polishing method will be described.

  In the ceramic roll for paper making process obtained by the polishing method, a directional region having the following shape is specifically formed on the outer peripheral surface. In this directional region, scratches having a direction different from the main direction may be mixed. In addition, the directionality of the scratches in the region other than the directionality region on the outer peripheral surface of the ceramic roll is not particularly limited. Examples of the scratches in the region other than the directional region include, for example, random directions, a mixture of scratches composed of a plurality of directions, non-linear scratches, and the like. It may be a scratch eye having a direction.

  According to the ceramic roll for papermaking process, as described above, since the main direction of the scratches has a directional area that is inclined with respect to the circumferential direction of the roll, in the press part of the papermaking process, The main direction of the scratches and the main fiber orientation direction of the wet paper made can be different. This is because the fiber orientation direction in the paper made is basically the flow direction in the paper making process, that is, the circumferential direction of the ceramic roll in the press part. Therefore, according to the ceramic roll, even when the paper web is pressed, the pulp fibers on the wet paper surface are less likely to be buried in the fine scratches in the directional region. Can be increased.

  As shown in the enlarged view of FIG. 2, the directional region has a belt-like shape with the main direction of the scratch eye (the arrow direction in FIG. 2) as the longitudinal direction. In addition, this strip | belt-shaped shape means the substantially rectangular shape which has a fixed width | variety, For example, the shape where the corner | angular of the vertex is taken may be sufficient even if it is not strictly a rectangle. The directional regions 7 are arranged at regular intervals along the axial direction of the ceramic roll 1 (lateral direction in FIG. 2).

  According to the ceramic roll, the directional regions are arranged at regular intervals along the axial direction as described above, so that the directional regions and other regions are alternately provided in the axial direction. . Therefore, when this ceramic roll is used in the press part of the papermaking process, the portion in contact with the directional region and the portion in contact with the region other than the directional region on the wet paper surface at the moment of leaving the roll surface Will exist. That is, according to the ceramic roll, even if the pulp fiber coincides with the main direction of the scratches in the directional region on the surface of the wet paper, and the pulp fibers are buried in the scratches, this directionality is maintained. Since the areas other than the areas are close to each other, the pulp fibers buried in the scratches can be kept to a very small part. That is, according to the ceramic roll, it is possible to prevent a certain amount of pulp fibers from being collected and buried in the scratches, and to further improve the peelability of the paper.

  The directional region has a belt-like shape as described above, and is formed in a zigzag shape along the circumferential direction of the ceramic roll (the vertical direction in FIG. 2). According to the ceramic roll 1, since the directional region 7 is formed in a zigzag shape along the circumferential direction in this way, there is a main direction conversion portion in the directional region 7. Therefore, when the ceramic roll is used for a press part or the like, even if the difference between the fiber orientation direction of the wet paper and the main direction of the scratches is small, the fibers are not easily buried in the scratches. Become. That is, even when the main direction of the scratch eye of the directional region 7 and the fiber orientation direction of a certain pulp fiber coincide with each other, in the above-mentioned conversion point, the main direction of the scratch eye is different from the direction. Pulp fiber burial can be confined to one or part of a small amount of fiber. Therefore, according to the ceramic roll 1, it is possible to further improve the peelability from the paper.

  The lower limit of the arithmetic average roughness (Ra) of the outer peripheral surface of the ceramic roll is preferably 0.2 μm, more preferably 0.4 μm, further preferably 0.6 μm, and particularly preferably 0.8 μm. On the other hand, the upper limit of the arithmetic average roughness (Ra) is preferably 2 μm, more preferably 1.6 μm, still more preferably 1.4 μm, and particularly preferably 1.2 μm. According to the ceramic roll, by setting the arithmetic average roughness (Ra) of the outer peripheral surface in the above range, it is possible to improve the paper separating property without reducing the smoothness of the wet paper to be pressed. When the arithmetic average roughness (Ra) of the outer peripheral surface is smaller than the above lower limit, the smoothness is too high and the paper releasability may be reduced. On the other hand, when the arithmetic average roughness (Ra) exceeds the above upper limit, the smoothness of the wet paper surface to be pressed is lowered, and the quality of the obtained paper may be lowered.

  The lower limit of the maximum height (Ry) of the outer peripheral surface of the ceramic roll is preferably 4 μm, and more preferably 6 μm. On the other hand, the upper limit of the maximum height (Ry) is preferably 12 μm, and more preferably 10 μm. According to the ceramic roll, by setting the maximum height (Ry) of the outer peripheral surface in the above range, it is possible to improve the paper separating property without reducing the smoothness of the wet paper to be pressed. When the maximum height (Ry) of the outer peripheral surface of the ceramic roll is smaller than the lower limit, the smoothness is too high and the peelability from the wet paper is lowered. On the contrary, when the maximum height (Ry) exceeds the upper limit, the smoothness of the wet paper to be pressed is lowered, and the paper quality may be lowered.

  The lower limit of the ten-point average roughness (Rz) of the outer peripheral surface of the ceramic roll is preferably 4 μm, and more preferably 6 μm. On the other hand, the upper limit of the ten-point average roughness (Rz) is preferably 12 μm, and more preferably 10 μm. According to the ceramic roll, by setting the ten-point average roughness (Rz) of the outer peripheral surface in the above range, it is possible to improve the paper separating property without reducing the smoothness of the wet paper to be pressed. If the ten-point average roughness (Rz) of the outer peripheral surface of the ceramic roll 1 is smaller than the lower limit, the smoothness is too high and the peelability from the wet paper may be reduced. On the contrary, when the ten-point average roughness (Rz) exceeds the upper limit, the smoothness of the wet paper to be pressed is lowered, and the quality of the paper may be lowered.

  The maximum height (Ry) and ten-point average roughness (Rz) are the same as arithmetic average roughness (Ra), according to JIS-B0601 (1994), with a cutoff λc of 2.5 mm and an evaluation length of 12. It is a value measured at 5 mm.

  The arithmetic average roughness (Ra), the maximum height (Ry), and the ten-point average roughness (Rz) of the outer peripheral surface are preferably in the above ranges regardless of the directional region and other regions. Further, the arithmetic average roughness (Ra), the maximum height (Ry), and the ten-point average roughness (Rz) are approximately five equally spaced in the axial direction of the ceramic roll 1 (when there are portions to be polished at both ends). And the average value measured at a total of 20 locations of 4 locations at approximately equal intervals in the circumferential direction. Each surface roughness can be measured using, for example, SJ-201P manufactured by Mitutoyo Corporation.

  According to the ceramic roll for papermaking process, the main direction of the scratch eye has a directional region inclined with respect to the circumferential direction of the roll, and this directional region further takes the shape and arrangement described above. When used in a press part or the like in a papermaking process, high releasability from wet paper can be exhibited.

  The method for polishing a ceramic roll for paper making process of the present invention is not limited to the above embodiment. For example, in the directional region forming process, the ceramic roll is rotated while the finisher device is oscillated. Instead, it may be performed only by translating in the axial direction. According to the polishing method, although the zigzag directional region is not formed, the directional region having the scratches in which the main direction is inclined with respect to the circumferential direction of the ceramic roll can be formed in this way. The resulting papermaking process ceramic roll can also have a high peelability from the paper while having a function of imparting smoothness to the paper.

  As described above, the method for polishing a ceramic roll for papermaking process according to the present invention can be suitably used when the ceramic roll for papermaking process used in a press part or the like in the papermaking process is polished as maintenance.

DESCRIPTION OF SYMBOLS 1 Ceramic roll for papermaking processes 2 Roll main body 3 Ceramic layer 4 Roll shell 5 Head 6 Axis 7 Directional area 11 Finisher device 12 Roll 13 Belt-shaped diamond grindstone 14 Base cloth 15 Diamond grindstone area 21 Ceramic roll for papermaking process 27 Directional area

Claims (6)

A rough polishing step for rough polishing the outer peripheral surface of the ceramic roll for papermaking process;
A semi-finishing process for adjusting the roughness of the outer surface of the ceramic roll for papermaking process;
A directional region forming step of forming a directional region by polishing on the outer peripheral surface of a ceramic roll for papermaking process,
A method for polishing a ceramic roll for a papermaking process, wherein a main direction of a scratch eye in the directional region is inclined with respect to a circumferential direction. In the directional region forming step,
Using a belt-shaped diamond grindstone that can be circulated across multiple rolls,
The outer peripheral surface of the papermaking process ceramic roll and the outer surface of the belt-shaped diamond grinding wheel are brought into contact with each other, and the belt-shaped diamond grinding stone is oscillated in the axial direction of the papermaking process ceramic roll while rotating the papermaking process ceramic roll. The method for polishing a ceramic roll for papermaking process according to claim 1. The belt-shaped diamond grindstone has a plurality of diamond grindstone regions disposed on the outer surface,
The method for polishing a ceramic roll for a papermaking process according to claim 2, wherein the diamond grinding wheel regions are arranged in a grid pattern at equal intervals in the longitudinal direction and the width direction of the belt-shaped diamond grinding stone. The diamond wheel area is a regular square,
The method for polishing a ceramic roll for a papermaking process according to claim 3, wherein the length of one side of the regular square is 3 mm or more and 7 mm or less.   The polishing of the ceramic roll for papermaking processes of any one of Claims 1-4 which further has the adjustment finishing process which adjusts the roughness of the outer peripheral surface of the ceramic roll for papermaking processes in which the directional area | region was formed again. Method.   A ceramic roll for a papermaking process obtained by the method for polishing a ceramic roll for papermaking according to any one of claims 1 to 5.

Images