JP2013112901A - Cylinder type sheet former - Google Patents

Abstract

A round net type papermaking machine capable of reducing variation in thickness of a board material with a simple configuration.
A paper making machine 1 includes a plurality of tanks 11A to 11D for storing a raw material slurry, a round net 13 immersed in the slurry, and making up a solid content in the slurry as it rotates, and the tank. Supply means 15 for supplying slurry, and discharge means 18 and 19 for discharging the slurry from the tank provided on the end side of the rotary shaft of the round net in the tank. The plurality of tanks include at least first tanks 11A and 11B and second tanks 11C and 11D. The discharge means has at least a first discharge means and a second discharge means respectively provided in the first and second tanks. The first discharge means 18 has a round net 13 with respect to the second discharge means 19. It is provided at a position facing each other.
[Selection] Figure 4

Description

  The present invention relates to a round net type paper machine, and more particularly to a round net type paper machine capable of reducing variations in the thickness of a board material with a simple configuration.

  2. Description of the Related Art Conventionally, for example, a board material (one example) used as a building material for a house is manufactured by a method called a papermaking method. Among them, in manufacturing using a round net type paper machine, a raw slurry is made with a plurality of round nets, a sheet formed by paper making is wound, and a plurality of sheets are laminated. After the laminated sheet is pressed, it becomes a board material for building materials through each process of steam curing and drying (see Patent Document 1).

  In addition, in order to reduce the variation in the thickness of the board made in the round net type paper machine, the deviation of the thickness is calculated by interrupting the paper making process based on the deviation and changing the number of sheets to be laminated. There has also been a proposal for reduction (see Patent Document 2).

JP 2004-231443 A JP 60-139894 A

  However, the technique of Patent Document 1 does not describe the point of reducing the variation in the thickness of the sheet-formed laminated sheet. Further, the technique of Patent Document 2 is cumbersome because the deviation is calculated, and since the number of stacked sheets is changed, a variation smaller than the thickness per sheet cannot be corrected, and fine adjustment is possible. There was a problem that it was not possible.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a papermaking machine that can reduce thickness variation of a board material with a simple configuration and can reduce variation with high accuracy. It is in.

In order to achieve the above object, the circular net paper machine of the present invention is:
A plurality of tanks for storing raw material slurry;
A round net that is immersed in the slurry and rolls up the solid content in the slurry as it rotates,
Supply means for supplying slurry to the tank;
In the round net-type papermaking machine provided on the end side of the rotary shaft of the round net in the tank, and having a discharge means for discharging the slurry from the tank,
The plurality of tanks have at least a first tank and a second tank,
The discharge means has at least first discharge means and second discharge means respectively provided in the first and second tanks,
The first discharge means is provided at a position facing the second discharge means across the round net.

  ADVANTAGE OF THE INVENTION According to this invention, the paper machine which can reduce the dispersion | variation in the thickness of a board with simple structure can be provided.

It is a side view which shows the structure of the round net-type papermaking machine of one form of this invention. It is a flowchart which shows the outline of the manufacturing process of the board material by a papermaking method. It is sectional drawing which shows the mode in a tank in the state which is rotating the round net. It is a perspective view which shows the structure of the tank in one form of this invention. It is a top view which shows the discharge direction of the slurry in each tank. It is a schematic diagram which shows the flow of the slurry of the tank of Fig.4 (a). It is a top view which shows the structure which weighted the discharge direction of each tank (comparative example). It is a figure which shows the result of having measured the board thickness after a press (comparative example). It is a figure which shows the result of having measured the board thickness after a press (this embodiment). It is a figure which shows the graph and the measuring method which compared the thickness of the board material manufactured with the apparatus (comparative example 1) like FIG. 7, and the board thickness manufactured with the apparatus of one form of this invention. It is a perspective view which shows the structure of the tank of the other form of this invention. It is a schematic diagram which shows the flow of the slurry of the tank of FIG. It is a schematic diagram which shows the flow of the slurry when the magnitude | size of a right-and-left discharge port is made the same. It is a perspective view which shows the structure of the tank of the further another form of this invention.

(First embodiment)
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  First, the flow of manufacturing board materials using papermaking will be briefly described. In this manufacturing method, as shown in FIG. 2, first, as step S1, a paper making process is performed, that is, a board raw material is made from slurry to form a laminated sheet and cut into a predetermined size to obtain a board (details will be described later). ). Next, the board is pressed in step S2, steam curing and drying are performed in step S3, and final processing and coating are performed in step S4, whereby a building board material is manufactured.

  A round net type papermaking machine 1 according to the present embodiment shown in FIG. 1 is used in the papermaking process of step S1. As shown in FIG. 1, the papermaking machine 1 includes a conveyor device 20 including a conveyor belt 21 made of felt, for example, and four tanks 11 </ b> A to 11 </ b> D (hereinafter simply referred to as “tanks”) disposed below the conveyor device 20. (Also referred to as a tank 11).

  In principle, the slurry containing the raw material of the board material is always supplied to the four tanks 11A to 11D. The tanks 11 </ b> A to 11 </ b> D are arranged at predetermined intervals along the feeding direction of the conveyor belt 21. In each tank 11, a cylindrical round net 13 formed in a mesh shape is disposed to make the raw material. The axial direction of the round net 13 is a direction substantially orthogonal to the feed direction of the conveyor belt 21. The round net 13 is configured to be rotated by a drive source (not shown). As an example, the rotational speed of the round net 13 is such that the moving speed of the surface of the round net is the same as the conveying speed of the conveyor belt 21. Is speed.

  A roller 23 configured to be rotatable and a cutter 26 disposed adjacent to the roller 23 are disposed on the downstream side in the feed direction of the conveyor belt 21. The roller 23 is for winding up the laminated sheet that has been sent.

The basic operation of the round netting machine shown in FIG. 1 is as follows.
First, the conveyor belt 21 is run while the slurry containing the board raw material is contained in the four tanks 11A to 11D, and the four round nets 13 are rotated according to the speed. By rotating the round net 13, the raw material in the slurry of each tank 11 is made by the round net 13 and transferred to the surface of the conveyor belt 21. When passing through each tank 11, the sheets are laminated one by one, and finally, when passing through all the tanks 11, a four-layer laminated sheet is finally formed.

  The laminated sheet is continuously sent to the downstream side by the conveyor belt 21, and is wound around the roller 23 when it is sent to the roller 23 in FIG. 1. The laminated sheet wound up by the roller 23 is peeled from the roller 23 by the cutter 26 at a predetermined timing, and is cut into a desired size. In this way, the board A that is the final form of the board material is created. The board A is then sent to the pressing process, curing / drying process, and processing / painting process. In addition, since these processes are conventionally well-known, detailed description is abbreviate | omitted.

  Next, with reference to FIGS. 3-6, the detailed structure of each tank 11A-11D is demonstrated. FIG. 3 is a cross-sectional view showing the inside of the tank 11 in a state where the circular net 13 is rotated. FIG. 4 is a perspective view for explaining the structure of the tank 11 in the present embodiment. In FIG. 4, illustration of the wall surface and the round net of the tank 11 is omitted, and the slurry supply port and the discharge port are schematically illustrated. FIG. 5 is a diagram showing the positions of the discharge ports 18 and 19 in the tanks 11A and 11B, and FIG. 6 is a schematic diagram of the slurry flow rate toward the discharge port 18 in FIG.

  As shown in FIG. 4, each of the tanks 11 </ b> A to 11 </ b> D has a slurry supply port 15 that is elongated in the width direction of the tank 11 (the horizontal direction in the drawing) on the upstream side. Since the slurry supply port 15 has such a shape, the slurry is supplied under substantially the same conditions over the entire width direction of the tank 11. As shown in FIG. 3, the slurry supplied from the upstream side of the tank 11 flows into the round net 13 while flowing along the round net 13, and the solid content in the slurry is changed to the round net 13 when flowing in. It is extracted. In this way, when flowing along the circular mesh 13, the slurry flows into the inner peripheral side of the circular mesh 13, but the inflow amount becomes maximum in the region D1 in FIG. 4A and in the region D2 in FIG. 4B ( Details will be described later).

  In the state where the round net 13 is rotated, as shown in FIG. 3, the liquid level L1 inside the round net 13 is lower than the outside.

  The slurry that has flowed into the round net 13 in this manner is discharged to the outside from the slurry discharge ports 18 and 19. As shown in FIG. 4A and FIG. 5, in the present embodiment, among the four tanks 11 </ b> A to 11 </ b> D, the two upstream tanks 11 </ b> A and 11 </ b> B are provided with a slurry discharge port 18 on the right side surface. .

  On the other hand, as for the two tanks 11C and 11D on the downstream side, as shown in FIGS. 4B and 5, a slurry discharge port 19 is provided on the left side surface. Although not particularly limited, in the present embodiment, as an example, the sizes of the slurry discharge ports 18 and 19 are the same.

  When the slurry discharge port 18 (one example) is provided on one side of the tank 11, the pressure of the slurry near the discharge port 18 is high (the flow rate is high), and the pressure is low (the flow rate is low) on the opposite side. . Further, the slurry supplied from the supply port 15 passes through the lower side of the circular mesh 13 and collides with the opposing surface 11a toward the opposing surface 11a of the supply port 15 and flows into the inner peripheral side of the circular mesh 13. It is discharged from the discharge port 18 (see FIG. 3). A part of the slurry also flows into the inner peripheral side of the round net 13 when passing through the lower side of the round net 13, but the opposing wall 11 a is larger than the flow rate to the inner peripheral side of the round net 13 during normal operation of the papermaking machine 1. Since the flow rate to the side is large, the slurry pressure in the tanks 11A and 11B is relatively larger in the vicinity of the facing surface 11a than in other regions.

  Therefore, in FIG. 4 (a), the area near the upper part of the opposing surface 11a and the discharge port 18 side (right side) is the highest pressure region D1, and the flow rate of the slurry flowing into the inner peripheral side of the round net 13 is also the region D1. The solid content produced by the round net 13 is relatively increased in the region D1 as compared with other regions. This phenomenon is the same in FIG. Due to the above action, the thickness of the sheet transferred to the conveyor belt 21 is thicker on the side of the discharge port 18 where the region D1 exists in FIG. 4A, and on the side of the discharge port 19 where the region D2 exists in FIG. It will become thicker, and there will be a difference between left and right.

  Such a variation in the thickness of the left and right sheets causes a variation in the thickness of the final board material. In particular, in the round net type paper machine having a plurality of tanks 11 as shown in FIG. 7, when the positions of the respective outlets 18 are unevenly located at the same position with respect to the round nets, the difference in thickness in each tank 11. Are superimposed, and the thickness variation of the laminated sheet becomes more remarkable.

  Further, when the thickness of the laminated sheet varies, there is a possibility that transfer failure may occur when the laminated sheet is pressed to transfer the pattern for the board in a subsequent process. Or, when water remains in the thick part of the laminated sheet, when the laminated sheet passes the roller 23 (see FIG. 1), a problem called “water cracking”, that is, water enters between the sheets, The water is compressed at the time of pressing, and the sheet breaks. Furthermore, the water remaining in the laminated sheet may cause separation of the sheets after pressing.

  In view of such a problem, in this embodiment, as shown in FIG. 5, the positions of the slurry discharge ports 18 and 19 are divided and provided to the left and right. Thereby, the position where the difference in the thickness of the raw material generated in each of the tanks 11A to 11D is dispersed, and the difference in thickness is relatively absorbed when the raw materials drawn up in each of the tanks 11A to 11D are stacked. Is possible. Therefore, a complicated configuration such as calculation of deviation is not required, and variations in board thickness can be efficiently reduced with a simple configuration.

  8A to 8C are a comparison between Comparative Example 1 and the present embodiment. The results of measuring the thickness of the board material after pressing are shown in FIG. 8A (Comparative Example 1) and FIG. 8B (this embodiment). FIGS. 8A and 8B show variations in thickness of one board material, where the thinner the plate thickness, the darker the thicker portion. In Comparative Example 1, as shown in FIG. 8A, the central portion of the board material was thick but the end portion side was thin, and the variation in the plate thickness was large. On the other hand, in this embodiment, as shown in FIG. 8B, variation in the plate thickness is suppressed over the entire board material.

  The graph of FIG. 8C shows the result of comparing the thickness when the board material manufactured by the apparatus as shown in FIG. 7 (Comparative Example 1) is overlapped with the thickness of the board material manufactured by the apparatus of this embodiment. Yes. The thickness of the board material was measured by stacking a predetermined number of boards as shown in the lower left figure of FIG. The above measurement was performed several times by increasing the number of boards to be stacked. In the graph, the left side shows the result of Comparative Example 1, and the right side shows the result of the present embodiment. The horizontal axis is the number of stacked boards, and the vertical axis is the stacked height. As is clear from this graph, the left and right heights of the boards in Comparative Example 1 are significantly different, whereas in this embodiment, the left and right heights are substantially the same. It was proved that the paper machine can greatly reduce the variation in the thickness of the board material.

  As described above, the tanks 11 </ b> A to 11 </ b> D are arranged in such a manner that the slurry discharge directions are the right side, right side, left side, and left side (see FIG. 5). The right side and the left side may be alternated. Further, all the slurry overflowing from the first tank 11A may be discharged from the left discharge port, or a part thereof may be supplied to the second tank 11B. The same applies to the tanks 11C and 11D.

(Second Embodiment)
The present invention may further include a tank 11-2 as shown in FIG.
In this tank 11-2, as shown in FIG. 9, the small opening part 18 'is formed in the one side of the left-right direction, and the large opening part 19' is formed in the other side. The difference in opening area between the two openings 18 'and 19' causes a difference in the flow rate of the slurry discharged from the large opening 19 'and the small opening 18'. Based on the difference, a pressure difference between the right and left is generated in the vicinity of the facing surface 11a. For this reason, the region D3 is higher in the region D3 on the large opening 19 ′ side and the region d3 on the small opening 18 ′ side in the upper part near the facing surface 11a. Accordingly, the amount of the raw material produced in the region D3 is relatively increased compared to the other regions.

  Further, in the second embodiment, since the flow rate to the large opening 19 ′ and the flow rate to the small opening 18 ′ are different, the flow velocity distribution in the tank 11-2 becomes unbalanced, and the discharge from the small opening 18 ′. In the region D4 (unevenly distributed to the small opening 18 ′ side from the center line L2) by a small amount, the pressure increases, the flow velocity becomes high, and the slurry passing through the round net 13 increases. Accordingly, since the amount of the finished slurry in the region D4 increases, the thickness increases.

  Therefore, as in the first embodiment, two of the four tanks on the upstream side are tanks as shown in FIG. 9, and the small opening 18 ′ is arranged on the left side and the region D4 is unevenly distributed on the left side (see FIG. 5). For the two tanks on the downstream side, a tank (not shown) in which the positions of the two openings 18 'and 19' are horizontally reversed is arranged, the small opening 18 'is arranged on the right side, and the region D4 is on the left side. Make it unevenly distributed. With such a configuration, as in the above-described embodiment, the positions where the thicknesses of the raw materials generated in the respective tanks differ are dispersed, and variations in the thickness of the boards to be manufactured can be effectively reduced.

  As is apparent from the above description, slurry discharge ports 18 'and 19' may be provided on both sides of the tank in the present invention. However, it is preferable that a difference is provided in the size of the left and right discharge ports. The reason for this is that when the size of the slurry outlet is the same on the left and right, as illustrated in FIG. 11, the flow of the slurry is subject to the left and right across the center line L2, and the flow velocity near the left and right outlets increases. On the other hand, since the flow velocity in the vicinity of the center line L2 becomes small, the thickness in the vicinity of the center line L2 increases, so that the position where the difference in the thickness of the raw material generated in each tank cannot be dispersed. This is because the position where the thickness increases or the position where the thickness decreases is formed in a symmetrical position in each tank, and even if the raw materials are stacked, it is difficult to reduce variation in the thickness of the board. On the other hand, in the first and second embodiments, and in Example 3 described later, the position where the thickness increases or decreases is formed at an asymmetric position in each tank. As a result, the thickness of the board can be reduced.

(Third embodiment)
The present invention may further include a tank 11-3 as shown in FIG. In the tank 11-3, the position of the slurry supply port 15 'is unevenly distributed on the left and right sides. In the example of FIG. 12, only one slurry supply port 15 ′ is arranged on the right side which is smaller than that of the above embodiment. The sizes of the slurry discharge ports 18 and 19 are the same on the left and right as an example.

  In such a tank 11-3, the sizes of the left and right slurry discharge ports 18 are the same, but since the supply ports 15 'are unevenly distributed, the supply ports 15' are relatively close to each other in the vicinity of the facing surface 11a. The pressure becomes high and a pressure difference between the left and right (flow velocity difference) occurs. As a result, compared to other regions, the region D4 on the supply port 15 'side, which is on the opposite surface 11a, has a relatively high pressure, and the amount of the finished paper is increased locally, resulting in variations in sheet thickness. . Similarly to the above, as an example, out of the four tanks, two upstream ones are tanks 11-3 as shown in FIG. 12, and two downstream ones are tanks in which the position of the slurry supply port 15 'is reversed horizontally ( (Not shown). With such a configuration, the position where the difference in the thickness of the raw material generated in each tank is dispersed, and the variation in the thickness of the board to be manufactured can be effectively reduced.

  As mentioned above, although several forms were illustrated and demonstrated about this invention, this invention is not limited to the specific structure shown above. For example, the number of tanks may be other than four. However, it is preferable that the number of tanks is an even number from the viewpoint of evenly distributing the variation in sheet thickness in each tank to the left and right.

The present invention has been described above by taking the first to third embodiments as examples. The gist of the present invention is as follows.
(1) a plurality of tanks (11) for storing raw material slurry;
A round net (13) immersed in the slurry and rolling up solids in the slurry with rotation;
Supply means (15) for supplying slurry to the tank (11);
A round net-type paper machine (1) provided on the end side of the rotary shaft of the round net (13) in the tank (11) and having discharge means (18, 19) for discharging the slurry from the tank )
The plurality of tanks (11) have at least a first tank (11A, 11B) and a second tank (11C, 11D),
The discharge means has at least a first discharge means (18) and a second discharge means (19) respectively provided in the first and second tanks,
The first netting means (18) is provided at a position facing the second ejection means (19) across the round net (13).

(2) In the round net type papermaking machine described in (1) above,
Each of the first tanks (11A, 11B) and the second tanks (11C, 11D) is provided with two each, a round net-type papermaking machine.
Thus, when two tanks are provided, the dispersion | variation in the thickness at the time of sheet | seat lamination | stacking can further be reduced.

(3) In the round net-type paper machine according to (1) or (2) above,
The first discharge means (18) is provided only on one of the side surfaces of the first tank (11A, 11B) on the rotating shaft side,
The second net discharging means (19) is provided on only one of the side surfaces on the rotating shaft side of the second tank (11C, 11D).
As described above, when the discharging means is provided only in one of the tanks, variation in the thickness of the board material can be reduced with a simple configuration.

(4) In the round net-type paper machine according to (1) or (2) above,
The first discharge means is an opening provided on both side surfaces of the first tank (11A, 11B) on the rotating shaft side, each having a first large opening (19 ′) having a different opening area, and a first One small opening (18 '), the first large opening (19') and the first small opening (18 ') are provided on opposite side surfaces;
The second discharge means is an opening provided on both side surfaces of the second tank (11C, 11D) on the rotating shaft side, each having a second large opening and a second small opening having different opening areas. The second large opening and the second small opening are provided on side surfaces facing each other,
The first and second large openings are provided opposite to each other with respect to the round net,
The first and second small openings are provided opposite to each other with respect to the round net.
In this way, by providing discharge ports on both side surfaces of the tank and having different opening areas, and changing the area ratio as appropriate, the flow rate of the discharged slurry can be changed as appropriate, and the thickness variation can be finely adjusted. .

(5) In the round net-type paper machine according to (1) or (2) above,
The round net type papermaking machine is characterized in that the supply means (15 ') is provided unevenly on one side in the rotational axis direction of the round net (13).
In this way, by unevenly distributing the slurry supply means, it becomes possible to change the flow rate distribution in the tank and adjust the amount of slurry that is made up in a specific region of the round net. Therefore, fine adjustment of thickness variation can be performed.

  It should be noted that other embodiments may be used as long as the thickness variation is reduced by combining a plurality of tanks where the positions where the thickness increases or decreases are asymmetric. For example, out of a total of four tanks, you may provide two tanks which have a drain outlet only on one side, and two tanks which have a drain outlet on both sides.

  In this case, in the tank that drains only on one side, one tank that has a drain outlet only on the left side and one tank that has a drain port only on the right side are provided. If the tank is provided with a large drain outlet and the tank on the other side is provided with a large drain outlet on the right side, the position where the thickness is large and the position where the thickness is small are asymmetrical with each other, and as a result, variation in thickness can be reduced. .

DESCRIPTION OF SYMBOLS 1 Round net-making machine 11A-11D, 11-2, 11-3 Tank 13 Round net | network 15, 15 'Slurry supply port 18, 18', 19, 19 'Slurry discharge port 20 Conveyor apparatus 21 Conveyor belt 23 Roller 26 Cutter A Board L1 Liquid level L2 Center line

Claims (5)

A plurality of tanks for storing raw material slurry;
A round net that is immersed in the slurry and rolls up the solid content in the slurry as it rotates,
Supply means for supplying slurry to the tank;
In the round net-type papermaking machine provided on the end side of the rotary shaft of the round net in the tank, and having a discharge means for discharging the slurry from the tank,
The plurality of tanks have at least a first tank and a second tank,
The discharge means has at least first discharge means and second discharge means respectively provided in the first and second tanks,
The round net type papermaking machine, wherein the first discharge means is provided at a position facing the second discharge means across the round net. In the round netting machine according to claim 1,
Each of the first tank and the second tank is provided two by two. In the round net-type paper machine according to claim 1 or 2,
The first discharge means is provided only on one of the side surfaces of the first tank on the rotating shaft side,
The second net discharging means is provided only on one of the side surfaces of the second tank on the rotating shaft side. In the round net-type paper machine according to claim 1 or 2,
The first discharge means is an opening provided on both side surfaces of the first tank on the rotating shaft side, and has a first large opening and a first small opening, each having a different opening area, The first large opening and the first small opening are provided on side surfaces facing each other,
The second discharge means is an opening provided on both side surfaces of the second tank on the rotating shaft side, each having a second large opening and a second small opening having different opening areas, The second large opening and the second small opening are provided on the side surfaces facing each other,
The first and second large openings are provided opposite to each other with respect to the round net,
The first and second small openings are provided opposite to each other with respect to the round net. In the round net-type paper machine according to claim 1 or 2,
The round net type papermaking machine is characterized in that the supply means is provided unevenly on one side of the round net in the rotation axis direction.