JP2003239187A - Twin-wire paper machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a twin-wire paper machine capable of preventing blade damages due to the impingement of white water on the blades in dewatering and capable of producing paper with uniform fiber dispersion free of any paper defect. <P>SOLUTION: The twin-wire paper machine includes, upstream of a pressure element 30, a white water recovering means 20 for recovering white water 15 extracted on the opposite roll side to suppress the interference of the white water 15 with the pressure element 30. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention supplies a fibrous suspension between a pair of opposing wires forming respective loops, and dehydrating the fibrous suspension sandwiched between the wires to remove the paper web. Forming twin wire paper machine.

[0002]

2. Description of the Related Art In the initial dewatering section of a twin wire paper machine,
Two forming wires (hereinafter referred to as wires) each forming a loop are provided. Then, the fibrous suspension (paper raw material liquid) is supplied from the head box between the two wires, and while the fibrous suspension is sandwiched and transferred by the wires, the fibrous suspension is fed by various dehydrating devices. Dehydration pressure is applied to the suspension. By applying the dehydration pressure, water is removed from the fibrous suspension to gradually form a fiber mat, which grows to form a web.

After this, the web is further concentrated by vacuum (vacuum suction) and squeezed and dehydrated in the press section of the next step. Next, the paper web is dried by a dryer, then surface-treated by a calendar unit and wound up by a reel unit into paper. The paper thus produced is required to have various qualities and characteristics depending on the intended use, and most of the required qualities and characteristics have a great influence on the formation process of the fiber mat that determines the basic structure of the paper. To be done.

In the process of forming a fiber mat, a difference in velocity and its change occur in the plane direction and the thickness direction between the mat formed by the dewatering pressure applied by a dewatering device and the fibrous suspension. It is considered that the dispersion state of is changed. Therefore, it can be said that the dispersion state of the fiber mat depends on the magnitude of the dehydration pressure, the working time, the fluctuation pattern, and the like.

By the way, as one of the important paper qualities, there is a texture representing the dispersion state of fibers. In order to improve the formation, it is necessary to disperse the fibers uniformly. In order to obtain a uniform distribution of the fibers, appropriate changes in the dehydration pressure should be applied to the fibrous suspension between the time when the fibrous suspension was supplied from the headbox and the time when the mat formation as a web was completed. It is important to give to. However, in the conventional general dewatering method, the suspension between the two wires on the forming roll is dewatered to form a fiber mat, and the maximum dewatering pressure at this time is approximately the tension of the wire and the forming roll. It is determined by the roll diameter and the amount of fiber mat formed increases as the dehydration progresses, and the pressure change gradually increases to this maximum dehydration pressure. There was a problem that the texture of paper was poor and poor.

Therefore, a dehydration method as disclosed in JP-A-55-137294 and JP-A-6-235185 has been proposed. In these dewatering methods, as shown in FIG. 4, the dewatering devices 9, 10, 11, 12 and the vacuum device 13 that apply dewatering pressure to the suspension 4 sandwiched between the wires 1 and 2 are run by the wires 1 and 2. In addition to being arranged along the line, some of the dehydrating devices 9 are arranged at positions facing the forming rolls 5. Then, the blade member 8 provided at the tip of the dehydrating device 9 is pressed against the forming roll 5 to generate a pulsed dehydrating pressure on the forming roll 5. The wires 1 and 2 are both loop-shaped and guided by a plurality of rolls 6 and 7, respectively. Suspension 4
Is ejected from the head box 3 onto the forming roll 5 and is sandwiched in a wedge-shaped gap formed by the wires 1 and 2.

[0007]

By the way, FIG. 5 corresponds to FIG.
FIG. 6 is a schematic diagram for explaining the dehydration situation with the suction forming roll shown in FIG. 6, and FIG. 6 is a distribution diagram of the cumulative dehydration amount on the side opposite to the roll with the suction forming roll of FIG. 4. Since the forming roll 5 corresponds to the first dehydrating section of the paper machine, the amount of dehydration from the suspension 4 on the forming roll 5 becomes extremely large. Particularly, when the wire wrap angle is within 10 °, about 25% of the flow rate jetted from the head box 3 is dehydrated to the opposite roll side as shown in FIG. The white water dehydrated to the forming roll side is sucked into the suction box 10 of the forming roll 5, while the white water 15 dehydrated to the non-roll side moves in the traveling direction of the wires 1 and 2 as shown by the arrow in FIG. Will be scattered along.

Under such a dehydrating condition, when the blade 8 of the dehydrating device 9 is pressed toward the forming roll 5 from a position facing the forming roll 5 for the purpose of improving formation as shown in FIG. A large amount of dewatered white water 15 on the upstream side of 9 collides violently with the blade 8. Therefore, the blade 8 is deformed due to the collision of the white water 15, and the deformation of the blade 8 causes the blade 8 to bite into the forming roll 5.
In some cases, defects such as uneven wear of the wire or damage to the wires 1 and 2 were induced. Even when the blade 8 is not deformed, the white water 15 that collides with the tip of the blade 8 squeezes between the blade 8 and the wires 1 and 2 and induces paper defects such as streaks, which cannot be said to be a uniform fiber dispersion. Was sometimes manufactured.

The present invention was devised in view of the above problems, and it is possible to prevent damage to the blade due to collision of white water at the time of dehydration and to manufacture a paper having a uniform fiber dispersion without paper defects. It is an object to provide a twin wire paper machine.

[0010]

SUMMARY OF THE INVENTION The present invention solves the above problems by suppressing interference with the pressure elements (blades, etc.) of white water dehydrated to the opposite roll side. That is, the twin wire paper machine of the present invention is characterized by including white water recovery means for recovering dewatered white water on the side opposite to the roll on the upstream side of the pressure element. In the present invention, the fibrous suspension is supplied between the first and second wires that face each other in a loop, and the inner surface side of the first wire and the outer surface side of the second wire are rolled. A twin wire paper machine in which a pressure element for applying a dehydration pressure to the inner surface of the second wire is arranged on the inner surface side of the loop of the second wire so as to face the roll is applied.

When a plurality of pressure elements are arranged along the running direction of the second wire, it is preferable to provide white water recovery means at the forefront end of these pressure element groups. Since the foremost pressure element is most affected by white water, by providing the white water recovery means at the foremost end in this way, it is possible to suppress interference between the foremost pressure element and white water and prevent a defect. Of course, it is also possible to provide white water recovery means for each pressure element.

A blade can be simply used as the white water recovery means. That is, the blade is arranged inside the second wire so as to face the roll. This blade is not for applying dehydration pressure to the loop inner surface side of the second wire like a pressure element, but guides white water along the blade surface in a direction away from the second wire and collects it. This is to prevent white water from colliding with the pressure element. Therefore, it is preferable that the pressure element can be placed farther from the second wire than the pressure element, and that the blade used as the pressure element has higher rigidity (the pressure element is preferably flexible). preferable). Also,
The shape of the white water recovery blade is curved toward the upstream side so that the white water that collides at the tip of the blade and bounces back does not collide with the wire surface again so that the white water can be easily guided to the outside along the surface of the white water recovery blade. The formed shape is preferable. A white water suction means for forcibly sucking the white water recovered by the white water recovery blade may be provided. By forcibly sucking the collected white water, the white water can be collected more efficiently. A vacuum box or the like can be used as the white water suction means.

The position of the white water recovery blade in the roll direction is
It is preferable that the tip be located at a distance of about 15 mm from the second wire. When the white water recovery blade is too far away from the first wire, the white water recovery efficiency decreases, and when the white water recovery blade is pushed into the first wire (that is, when the distance becomes negative), a streak occurs due to the inclusion of white water. This is because the white water recovery blade itself may be deformed. Preferably, position adjusting means for adjusting the position of the white water recovery blade in the roll direction is provided so that the white water recovery blade can be freely adjusted to a position with good recovery efficiency. The white water recovery blade receives pressure from the dewatered water on the side opposite to the roll, but this pressure changes depending on the position in the roll direction. Therefore, a pressure detection means for detecting the pressure acting on the white water recovery blade is provided and detected. If the white water recovery blade is moved so that the pressure becomes an appropriate pressure, the white water recovery blade can be easily adjusted to an appropriate position.

On the other hand, the position of the pressure element in the roll direction is preferably a position where the tip of the pressure element is pushed into the roll side from the loop inner surface side of the first wire by about 1 mm so that the fibers can be dispersed by applying pressure. Preferably, position adjusting means for adjusting the position of the pressure element in the roll direction is provided so that the position can be freely adjusted to a position where proper fiber dispersion can be performed. More preferably, pressure detection means for detecting the pressure acting on the pressure element is provided, and the position of the pressure element in the roll direction is adjusted and moved so that the detected pressure becomes an appropriate pressure.

A general pressure sensor can be used as the pressure detecting means. When the pressure sensor is provided on the white water recovery blade or the pressure element, the pressure acting on the white water recovery blade or the pressure element can be directly detected. Further, since the reaction force of the pressure acting on the white water recovery blade and the pressure element acts on the roll surface, a pressure sensor is provided on the roll surface and acts on the roll surface via white water, wire and fibrous suspension. The pressure acting on the white water recovery blade or the pressure element may be indirectly detected from the pressure.

The pressure element and the white water recovery blade are arranged so as to face each other. The roll is a solid roll or a roll having a porous band wound around the roll surface so that excess white water can be recovered, or the roll surface has various shapes. Although it may have a groove, it is preferably a suction forming roll. With the suction forming roll, the white water that is dehydrated to the roll side can be forcibly sucked in by the suction box, so the amount of white water dehydrated to the anti-roll side that is about to be discharged due to the effect of centrifugal force. It can reduce itself.

By using the above twin wire paper machine, papermaking can be carried out by the following method. That is, the pressure acting on the white water collecting blade is detected by the pressure detecting means, and the paper is manufactured while the position adjusting means adjusts the position of the white water collecting blade in the roll direction so that the detected pressure falls within an appropriate range. Of. According to such a papermaking method, it is possible to reliably prevent the inclusion of white water at the tip of the pressure element, and to manufacture a high-quality paper having a uniform fiber mixture and having no problems such as streaks.

The pressure acting on the white water collecting blade and the pressure element is detected by each pressure detecting means, and each position adjusting means detects the pressure of the white water collecting blade and the pressure element so that each detected pressure falls within an appropriate range. It is also possible to manufacture the paper while adjusting the respective positions in the roll direction. According to such a papermaking method, the dewatering pressure of the pressure element can be optimized, so that it is possible to produce high-quality paper in which the fiber blend is further uniformized.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (A) First Embodiment FIG. 1 is a side view showing a configuration of a main part of a twin wire paper machine according to a first embodiment of the present invention. In FIG. 1, the same parts as those of the conventional twin wire paper machine shown in FIG. 4 are designated by the same reference numerals.

As shown in FIG. 1, the forming roll 5
A pair of wires 1 and 2 are wound around. The wires 1 and 2 are both loop-shaped, and one wire (first wire
Wire) 1 has a forming roll 5 formed on the inner surface of the loop.
And the other wire (second wire) 2 is wound around the outer surface of the loop around the forming roll 5. A suction box 10 is provided in a range (wire wrap range) around which the wires 1 and 2 of the forming roll 5 are wound. A plurality of flexible pressing blades 30 as pressure elements are arranged inside the wire 2 facing the suction box 10 along the traveling direction of the wires 1 and 2. These pressing blades 30 and 30 constitute a dehydrating device that applies a pulsed dehydration pressure to the fibrous suspension 4 which is the raw material liquid sandwiched between the wires 1 and 2 to homogenize the fiber mixture. There is.

In this embodiment, the front pressing blade 30
A blade (white water recovery blade) 20 dedicated to recovering the white water 15 is arranged in proximity to the upstream side of the. The white water recovery blade 20 has a shape in which the tip is gently curved toward the upstream side, and is made more rigid than the pressing blade 30. The position of the white water recovery blade 20 in the roll direction is set so that the tip of the blade 20 comes close to the inner surface of the wire 2 or comes into contact with the wire 2 with a kiss touch.

Further, the white water recovery blade 20 is provided with a pressure sensor 40 and a displacement sensor-equipped moving device 50 for position detection. The pressure sensor 40 is a sensor that detects the pressure that acts on the white water recovery blade, and mainly detects the pressure from the white water that collides with the white water recovery shake during dehydration. Further, the moving device 50 is a device for moving and adjusting the position of the white water recovery blade 20 in the roll direction, and the current position can be confirmed by a displacement sensor.

With such a configuration, the head box 3
The fibrous suspension 4 supplied between the wires 1 and 2 is transferred onto the suction box 10 while being sandwiched between the wires 1 and 2, and is dehydrated by the surface pressure of the wires 1 and 2 and the suction force of the suction box 10. To be done. Further, even on the side opposite to the suction forming roll 5, dehydration proceeds due to the surface pressure and centrifugal force of the wires 1 and 2, and the dehydrated white water 1
5 diverges inside the wire 2 along the traveling direction of the wires 1 and 2.

At this time, the white water 15 dehydrated to the opposite roll side
Is guided and collected in the direction away from the wire 2 along the surface of the white water recovery blade 20. As a result, the amount of white water 15 that collides with the pressing blade 30 is suppressed, and the deformation of the pressing blade 30 due to the collision of a large amount of white water 15 and the occurrence of streaks due to the spillage of the white water 15 between the pressing blade 30 and the wire 2 occur. Can be prevented. That is, according to the twin wire paper machine of the present embodiment, it is possible to prevent the pressing blade 30 from being damaged by the collision of the white water 15 at the time of dehydration, and to manufacture a paper having a uniform fiber dispersion without paper defects such as streaks. it can.

The position of the white water collecting blade 20 is properly adjusted by detecting the pressure acting on the white water collecting blade 20 with the pressure sensor 40 and adjusting the position with the moving device 50 so that the detected pressure becomes an appropriate pressure. Can be adjusted in position. Since the white water recovery blade 20 is not intended to improve fiber dispersion, it is not necessary to generate a high dehydration pressure in the fiber suspension 4. Therefore, although the proper position of the white water recovery blade 20 and a specific position control method will be described later (also described in the second embodiment), at least as described above, the wire 2 is brought into close proximity or is contacted with a kiss touch. If the position is adjusted as described above, the white water recovery blade 20 is not pressed against the wire 2, and the occurrence of streaks due to the spillage of the white water 15 and the intrusion into the wire 2 due to the deformation of the white water recovery blade 20 can be avoided. can do.

(B) Second Embodiment FIG. 2 is a side view showing the configuration of the main part of a twin wire paper machine according to the second embodiment of the present invention. Note that, in FIG. 2, parts common to the first embodiment are denoted by the same reference numerals. In this embodiment, as shown in FIG. 2, the flexible pressing blade 3 is arranged along the traveling direction of the wire 2.
White water recovery blades 25, 26,
27 are provided. Each white water recovery blade 25,2
6, 27 are arranged close to the upstream side of the corresponding pressing blades 35, 36, 37, and the corresponding pressing blades 3
5, 36, 37 together with a displacement device 55 with a displacement sensor,
It is set to 56 and 57. In FIG. 2, three sets of units 65, 66, 67 including the pressing blade, the white water collecting blade, and the moving device are arranged in the traveling direction of the wire 2.

With such a structure, the white water 15 dehydrated to the opposite roll side is collected by each of the units 65, 66 and 67. The accumulated dehydration amount of the white water 15 is the pressing blade 35 at the front.
However, the white water 15 is also dehydrated between the pressing blades 35 and 36 or between the pressing blades 36 and 37. Therefore, by providing the white water recovery blades 25, 26, 27 for each of the units 65, 66, 67 to recover the white water 15, the white water 15 dehydrated between the pressing blades 35, 36 or between the pressing blades 36, 37 is removed. It is also possible to prevent the pressing blades 36 and 37 from colliding with each other, prevent the pressing blades 36 and 37 from being damaged, and manufacture a paper having a more uniform fiber mixture.

In this embodiment, a pressure sensor 60 for detecting the roll surface pressure is arranged inside the forming roll 5. The pressure sensor 60 rotates together with the forming roll 5 and continuously detects the pressure acting at each position in the circumferential direction. Forming roll 5
Since the reaction force of the pressure acting on the white water recovery blades 25, 26, 27 and the pressing blades 35, 36, 37 acts on the surface of the roll, the pressure sensor 60 detects changes in the pressure on the roll surface to collect the white water. Blades 25, 26, 2
The pressure acting on 7 and the pressing blades 35, 36, 37 can be indirectly detected.

Here, FIG. 3 shows white water recovery blades 25 and 2.
6 and 27 and the pressing blades 35, 36, and 37 are explanatory views for explaining the position control method, and FIG. 3A is a distance d from the roll surface to each blade tip and a pressure (pressure) acting on the roll surface. (Detection value of the sensor 60),
FIG. 3B is a schematic diagram for explaining the definition of the distance d in FIG. The position control direction described below can also be applied to the position control of the white water recovery blade 20 according to the first embodiment.

First, the white water recovery blades 25, 26, 27
For the position of the white water recovery blades 25, 26, 27
Is too far away from the wire 2, the efficiency of collecting the white water 15 is reduced, and the white water collecting blades 25, 26, 27 are connected to the wire 2.
It is necessary to take into consideration the fact that when it is pushed into, the streak is generated due to the spillage of the white water 15 and the white water recovery blades 25, 26, 27 themselves are deformed. Therefore, the proper positions of the white water recovery blades 25, 26, 27 are as shown in FIG.
As indicated by a black bar in (a), a position separated from the surface of the forming roll 5 by a total thickness of the thickness of the wires 1 and 2 and the thickness of the fibrous suspension 4 between the wires 1 and 2 is set. As a reference, it is on the side of the white water collision pressure region, and specifically, the range of 0 to 15 mm from the reference position (the inner surface of the wire 2) is the proper position.

On the other hand, at the proper positions of the pressing blades 35, 36 and 37, it is necessary to compress the fiber suspension 4 between the wires 1 and 2 to disperse the fibers. As shown in, it becomes the deformation area side between wires from the reference position,
Specifically, the range pushed from the reference position to the roll side by 1 to 3 mm is the proper position. Each white water recovery blade 2
5, 26, 27 and the position control of the pressing blades 35, 36, 37 are performed by the pressure sensor 6 provided on the forming roll 5.
Based on the detected value of 0. That is, a pressure diagram as shown by the solid line in FIG. 3A is prepared in advance, and the proper pressure range corresponding to the proper position is calculated. Then, the white water recovery blades 25, 26, 27 and the pressing blades 35, 3 are controlled by controlling the moving devices 55, 56, 57 so that the detection value of the pressure sensor 60 falls within an appropriate pressure range.
Adjust the positions of 6, 37. The position control described above can be performed by automatic control or manually by an operator. In the case of automatic control, the pressure diagram is stored in advance in the control device, and each moving device 55, is arranged in the control device so that the detection value of the pressure sensor 60 falls within an appropriate pressure range.
Feedback control is performed on 56 and 57.

In this way, each white water recovery blade 25, 2
6, 27 and the pressing blades 35, 36, 37 while performing the papermaking while controlling the positions of the pressing blades 35, 36, 37.
The dehydration pressure of 36, 37 can be optimized. Further, it is possible to reliably prevent the occurrence of streaks due to the inclusion of white water between the pressing blades 35, 36, 37 and the wire 2. As a result, it becomes possible to produce high-quality paper with a uniform fiber blend.

Since the thickness of the fibrous suspension 4 becomes thinner as the dehydration progresses, the reference position shown in FIG. 3 (a) (from the surface of the forming roll 5 to the thickness of the wires 1, 2 and the wire 1, The position separated by the total thickness of the fibrous suspension 4 between the two) approaches the surface of the forming roll 5 on the downstream side in the traveling direction. Therefore, the pressure diagram shown in FIG. 3A also differs depending on the position where the blade is arranged. Therefore, in order to perform accurate position control, it is preferable to create a pressure diagram corresponding to the arrangement position of each blade in advance and input it to the control device.

(C) Others Two embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications may be made without departing from the spirit of the present invention. be able to. For example, in the second embodiment, the configuration in which the white water recovery blades 25, 26, 27 and the pressing blades 35, 36, 37 are unitized has been described, but the white water recovery blades 25, 26, 27 and the pressing blades 35, 36,
37 are individually arranged, and the moving device is also used for each blade 2
5, 26, 27, 35, 36, 37 may be provided independently. Further, also in the second embodiment, each blade 25, 26, 2
A pressure sensor may be provided on each of 7, 35, 36, and 37 to perform optimum position control based on the pressure value of each blade 25, 26, 27, 35, 36, 37.

Further, the number of white water collecting blades arranged upstream of the pressing blade (second embodiment) or the pressing blade group (first embodiment) is not limited to one as in each embodiment. Alternatively, a plurality of white water recovery blades may be arranged. Further, suction means such as a vacuum box may be added to the white water recovery blade so that the white water recovered by the white water recovery blade can be forcibly sucked. As a result, the recovered white water can be continuously removed to the outside, so that the white water can be recovered more efficiently.

Further, the white water collecting means according to the present invention is not limited to the blade shape as in the embodiment. Any shape may be used as long as it can prevent white water dehydrated at least on the opposite roll side from colliding with the pressing blade. Therefore, for example, the shape may be thicker depending on the traveling direction of the wire, or may be a guide plate as long as the rigidity is ensured. The pressure element is not limited to the blade shape as in the embodiment, and as long as it can apply a pulsed dehydration pressure to the fibrous suspension sandwiched between the wires, a roll shape Member or rod-shaped member may be used. In the case of a blade shape, a fixed blade may be used instead of the flexible blade as in the embodiment.

[0037]

As described in detail above, according to the twin-wire paper machine of the present invention, the white water recovery means collects the white water that is dewatered to the opposite roll side, thereby suppressing the interference of the white water with the pressure element. be able to. As a result, it is possible to avoid deformation of the pressure element, or bite into the roll due to deformation, and even if the pressure element does not deform, white water that collides with the tip sneak in between the pressure element and the wire, causing streaks, etc. Since it is possible to prevent the paper defect from being induced, it is possible to prevent the pressure element from being damaged, and it is possible to produce a high-quality paper having a uniform fiber blend and no paper defect.
Stable operation becomes possible.

[Brief description of drawings]

FIG. 1 is a side view showing a main configuration of a twin wire paper machine according to a first embodiment of the present invention.

FIG. 2 is a side view showing a main part configuration of a twin wire paper machine according to a second embodiment of the present invention.

FIG. 3 is a diagram for explaining a method of controlling the proper positions of the white water recovery blade and the pressing blade, (a) showing a relationship between the roll surface pressure and the distance “d” from the roll to the tip of the blade, and (b). FIG. 6 is a diagram for explaining the definition of the distance d in (a).

FIG. 4 is a side view showing a configuration of a dehydrating section of a conventional twin wire paper machine.

FIG. 5 is an enlarged view showing a dehydration situation with the suction forming roll shown in FIG. 4.

FIG. 6 is a distribution diagram of a cumulative amount of dehydration on the side opposite to the roll in the suction forming roll of FIG.

[Explanation of symbols]

1, 2 wire 3 head box 4 Fibrous suspension 5 Suction forming roll 10 suction box 15 White water 20, 25, 26, 27 White water recovery blade 30, 35, 36, 37 Pressing blade 40,60 Pressure sensor 50,55,56,57 Moving device with displacement sensor 65,66,67 units

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masanobu Matsumoto             Hiroshima Prefecture Mihara City Itozakicho 5007 Mitsubishi Heavy Industries             Paper and printing machinery division (72) Inventor Junichi Ibushi             Hiroshima Prefecture Mihara City Itozakicho 5007 Mitsubishi Heavy Industries             Paper and printing machinery division F-term (reference) 4L055 CD06 CE50 CE58 CE59 CE60                       CE63 DA09 DA16 DA17 FA09                       FA30

Claims (12)

[Claims] 1. A fibrous suspension is supplied between first and second wires that face each other in a loop, and the inner surface side of the loop of the first wire and the outer surface side of the loop of the second wire are respectively supplied. In a twin-wire paper machine that wraps a roll and dehydrates the fibrous suspension sandwiched between the first and second wires, the twin wire paper machine is disposed inside the loop of the second wire so as to face the roll. And a pressure element for applying dehydration pressure to the loop inner surface side of the second wire, and white water recovery means for recovering the dehydrated white water on the loop inner surface side of the second wire on the upstream side of the pressure element. A twin wire paper machine characterized by being equipped. 2. A plurality of the pressure elements are arranged along the traveling direction of the second wire, and the white water recovery means is provided at the foremost end of the pressure element group.
Twin wire paper machine described in. 3. A blade for collecting white water as the white water collecting means, wherein a blade for collecting white water is arranged on the inner surface side of the loop of the second wire so as to face the roll.
Or the twin wire paper machine described in 2. 4. The twin wire paper machine according to claim 3, wherein the white water recovery blade has a shape in which a tip thereof is curved toward an upstream side. 5. The twin wire paper machine according to claim 3, further comprising white water suction means for sucking white water collected by the white water collecting blade. 6. The twin wire paper machine according to claim 3, further comprising position adjusting means for adjusting a position of the white water recovery blade in the roll direction. 7. The twin wire paper machine according to claim 6, further comprising pressure detection means for detecting a pressure acting on the white water recovery blade. 8. The twin wire paper machine according to claim 6, further comprising position adjusting means for adjusting a position of the pressure element in the roll direction. 9. The twin wire paper machine according to claim 8, further comprising pressure detection means for detecting a pressure acting on the pressure element. 10. The twin wire paper machine according to claim 1, wherein the roll is a suction forming roll. 11. The twin wire paper machine according to claim 7, wherein the pressure detecting means detects the pressure acting on the white water recovery blade, and the position adjusting means adjusts the detected pressure to fall within an appropriate range. A paper making method, characterized in that the paper is produced while adjusting the position of the white water recovery blade in the roll direction. 12. The twin wire paper machine according to claim 9, wherein the pressures acting on the white water recovery blade and the pressure element are detected by the pressure detection means, and the detected pressures are within respective appropriate ranges. A papermaking method, characterized in that the paper is produced while adjusting the respective positions of the white water recovery blade and the pressure element in the roll direction by the respective position adjusting means.